JP7414457B2 - Resist composition and resist pattern forming method - Google Patents

Description

The present invention relates to a resist composition and a resist pattern forming method.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed and developed to form a resist pattern in a predetermined shape on the resist film. The process of A resist material whose characteristics change so that the exposed portion of the resist film dissolves in a developer is called a positive type, and a resist material whose characteristics change so that the exposed portion of the resist film does not dissolve in a developer is called a negative type.
In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, advances in lithography technology have led to rapid miniaturization of patterns. As a technique for miniaturization, generally the wavelength of the exposure light source is shortened (higher energy). Specifically, in the past, ultraviolet rays such as g-line and i-line were used, but now semiconductor devices are mass-produced using KrF excimer laser light and ArF excimer laser light. . Further, studies are also being conducted on EUV (extreme ultraviolet), EB (electron beam), X-rays, etc., which have shorter wavelengths (higher energy) than these excimer laser beams.

Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with minute dimensions.
As a resist material that satisfies these requirements, chemically amplified resist compositions have conventionally been used that contain a base component whose solubility in a developer changes due to the action of an acid, and an acid generator component that generates an acid upon exposure. is used.
For example, when the above developer is an alkaline developer (alkaline development process), a positive chemically amplified resist composition consists of a resin component (base resin) whose solubility in the alkaline developer increases due to the action of acid, Those containing the following ingredients are generally used. When a resist film formed using such a resist composition is selectively exposed during resist pattern formation, acid is generated from the acid generator component in the exposed area, and the polarity of the base resin increases due to the action of the acid. As a result, the exposed portion of the resist film becomes soluble in the alkaline developer. Therefore, by alkali development, a positive pattern is formed in which the unexposed portions of the resist film remain as a pattern.
On the other hand, when such a chemically amplified resist composition is applied to a solvent development process using a developer containing an organic solvent (organic developer), as the polarity of the base resin increases, the organic developer Since the solubility in the liquid decreases, the unexposed portions of the resist film are dissolved and removed by the organic developer, forming a negative resist pattern in which the exposed portions of the resist film remain as a pattern. A solvent development process for forming a negative resist pattern in this manner is sometimes referred to as a negative development process.

In the above-mentioned chemically amplified resist composition, in order to suppress film thinning of the resist film during resist pattern formation and improve the difference in solubility (dissolution contrast) between exposed and unexposed parts of the resist film, a developer is added. It is known to incorporate a dissolution inhibitor to suppress solubility in (for example, see Patent Documents 1 to 3).

In recent years, photofabrication has become the mainstream of precision microfabrication technology. Photofabrication is a process in which the chemically amplified resist composition is applied to the surface of a workpiece to form a resist film, a resist pattern of a predetermined shape is formed on the resist film, and this is used as a mask to perform chemical etching. A processing technology that manufactures various precision parts by performing electrolytic etching or electroforming, which mainly uses electroplating.

Japanese Patent Application Publication No. 2006-328241 Japanese Patent Application Publication No. 2007-206425 Japanese Patent Application Publication No. 2008-122932

In such photofabrication, a thick resist film with a film thickness on the order of microns, for example, is formed on the surface of the workpiece depending on the application, and a resist pattern is formed and etching etc. are performed. There is. For example, in the development of three-dimensional structured devices (three-dimensional NAND), memory capacity is increased by vertically stacking several dozen layers of cells fabricated using thick film resist patterns.
As a result of studies conducted by the present inventors, when a thick resist film on the order of microns was formed using a chemically amplified resist composition containing a conventional dissolution inhibitor, a resist pattern was formed, and etching was performed. In some cases, the etching resistance was insufficient. On the other hand, when a thick resist film is formed using a chemically amplified resist composition that does not contain a dissolution inhibitor and a resist pattern is formed, the thickness of the resist film is reduced during the formation of the resist pattern, and the desired result is not achieved. In some cases, a pattern having a shape could not be formed.

The present invention has been made in view of the above circumstances, and provides a resist composition that has good etching resistance and can form a pattern with a good shape, and a resist pattern forming method using the resist composition. The task is to do so.

In order to solve the above problems, the present invention employs the following configuration.
That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure to light and whose solubility in a developing solution changes due to the action of the acid. and a dissolution inhibitor (Z) that suppresses solubility in a developer, and the dissolution inhibitor (Z) has a mass average molecular weight of 3000 or less and contains a A resist composition containing a compound (Z1) having a phenolic hydroxyl group or a carboxyl group, and a compound (Z2) having a mass average molecular weight of 3000 or less and represented by the following general formula (z2).

［式中、Ｒ_ｚ ^２０は酸解離性基である。Ｒ_ｚ ^３０は水素原子又は有機基である。ｎ１は１～６の整数であり、ｎ２は０～５の整数である。ただし、ｎ１＋ｎ２＝６である。］

[In the formula, R _z ²⁰ is an acid dissociable group. R _z ³⁰ is a hydrogen atom or an organic group. n1 is an integer from 1 to 6, and n2 is an integer from 0 to 5. However, n1+n2=6. ]

A second aspect of the present invention includes a step (i) of forming a resist film on a support using the resist composition, a step (ii) of exposing the resist film, and a step (ii) of exposing the resist film to light. This is a resist pattern forming method including a step (iii) of developing and forming a resist pattern.

According to the present invention, it is possible to provide a resist composition that has good etching resistance and can form a pattern with a good shape, and a method for forming a resist pattern using the resist composition.

In this specification and the claims, the term "aliphatic" is a relative concept to aromatic, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the "alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups.
A "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
"Fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which some or all of the hydrogen atoms of an alkyl group or alkylene group are substituted with fluorine atoms.
"Constituent unit" means a monomer unit (monomer unit) that constitutes a high molecular compound (resin, polymer, copolymer).
When describing "may have a substituent" or "may have a substituent", there are two cases in which a hydrogen atom (-H) is substituted with a monovalent group, and a case in which a methylene group (-CH ₂ -) is substituted with a divalent group.
“Exposure” is a concept that includes radiation irradiation in general.

"A structural unit derived from an acrylic ester" means a structural unit formed by cleavage of an ethylenic double bond of an acrylic ester.
"Acrylic acid ester" is a compound in which the hydrogen atom at the end of the carboxy group of acrylic acid (CH ₂ =CH-COOH) is substituted with an organic group.
In the acrylic ester, the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. The substituent (R ^α0 ) substituting the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom, such as an alkyl group having 1 to 5 carbon atoms, a halogenated group having 1 to 5 carbon atoms, Examples include alkyl groups. In addition, there are also itaconic acid diesters in which the substituent (R ^α0 ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R ^α0 ) is substituted with a hydroxyalkyl group or a group modifying the hydroxyl group. shall be included. Note that the α-position carbon atom of the acrylic acid ester is the carbon atom to which the carbonyl group of acrylic acid is bonded, unless otherwise specified.
Hereinafter, an acrylic ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylic ester. In addition, acrylic esters and α-substituted acrylic esters are sometimes collectively referred to as "(α-substituted) acrylic esters."

"A structural unit derived from acrylamide" means a structural unit formed by cleavage of the ethylenic double bond of acrylamide.
In acrylamide, the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and one or both of the hydrogen atoms of the amino group of acrylamide may be substituted with a substituent. Note that the carbon atom at the α-position of acrylamide is the carbon atom to which the carbonyl group of acrylamide is bonded, unless otherwise specified.
As the substituent for substituting the hydrogen atom bonded to the carbon atom at the α-position of acrylamide, the same ones as those listed as the substituent at the α-position (substituent (R ^α0 )) in the α-substituted acrylic ester can be used. Can be mentioned.

The term "structural unit derived from hydroxystyrene" means a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene. "A structural unit derived from a hydroxystyrene derivative" means a structural unit formed by cleavage of an ethylenic double bond of a hydroxystyrene derivative.
The term "hydroxystyrene derivative" is a concept that includes hydroxystyrene in which the hydrogen atom at the α-position is substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. These derivatives include those in which the hydrogen atom of the hydroxyl group of hydroxystyrene is replaced with an organic group; the hydrogen atom at the α position may be substituted with a substituent; Good examples include those in which a substituent other than a hydroxyl group is bonded to the benzene ring of hydroxystyrene. Note that the α-position (α-position carbon atom) refers to a carbon atom to which a benzene ring is bonded, unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents as those listed as the substituent at the α-position in the α-substituted acrylic ester.

"A structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative" means a structural unit formed by cleavage of the ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative.
The term "vinylbenzoic acid derivative" is a concept that includes vinylbenzoic acid in which the hydrogen atom at the α-position is substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. These derivatives include those in which the hydrogen atom of the carboxy group of vinylbenzoic acid is substituted with an organic group; the hydrogen atom at the α position may be substituted with a substituent; Examples include those in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinylbenzoic acid, which may be an optional vinyl benzoic acid. Note that the α-position (α-position carbon atom) refers to a carbon atom to which a benzene ring is bonded, unless otherwise specified.

The term "styrene derivative" is a concept that includes styrene in which the hydrogen atom at the α-position is substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include those in which a substituent is bonded to the benzene ring of hydroxystyrene in which the hydrogen atom at the α-position may be substituted with a substituent. Note that the α-position (α-position carbon atom) refers to a carbon atom to which a benzene ring is bonded, unless otherwise specified.
"Structural unit derived from styrene" and "structural unit derived from styrene derivative" refer to a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.

The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, specifically an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group). , n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group).
In addition, examples of the halogenated alkyl group as a substituent at the α-position include a group in which part or all of the hydrogen atoms of the above-mentioned "alkyl group as a substituent at the α-position" are substituted with a halogen atom. It will be done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, with a fluorine atom being particularly preferred.
Further, specific examples of the hydroxyalkyl group as a substituent at the α-position include a group in which part or all of the hydrogen atoms of the above-mentioned "alkyl group as a substituent at the α-position" are substituted with a hydroxyl group. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

In this specification and the claims, some structures represented by chemical formulas may contain asymmetric carbon atoms and may have enantiomers or diastereomers. In that case, one chemical formula represents these isomers. These isomers may be used alone or as a mixture.

(Resist composition)
The resist composition according to the first aspect of the present invention is a resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid.
One embodiment of such a resist composition includes a base component (A) whose solubility in a developer changes due to the action of an acid (hereinafter also referred to as "component (A)"), and a dissolution component that suppresses solubility in a developer. Examples include resist compositions containing an inhibitor (Z) (hereinafter also referred to as "component (Z)") and an organic solvent component (S) (hereinafter also referred to as "component (S)").

The resist composition of this embodiment is suitable for resist pattern formation in which exposure is performed using ultraviolet light such as g-line or i-line, or an exposure light source such as KrF excimer laser.
Further, the resist composition of the present embodiment is suitable for forming a resist film of, for example, 1 to 10 μm on a support, and is particularly suitable for forming a resist pattern by forming a thick resist film. It is suitable for forming. The thick film here refers to a film with a thickness of 3 μm or more. The resist composition of this embodiment is preferably one suitable for forming a resist film having a thickness of 3 μm or more, within this range, a thickness of 3.5 μm or more, and more preferably 4 μm or more. It is.

When a resist film is formed using such a resist composition and the resist film is selectively exposed to light, acid is generated in the exposed areas of the resist film, and due to the action of the acid, the developer of component (A) While the solubility of component (A) in the developer changes in the unexposed areas of the resist film, the solubility of component (A) in the developer does not change, so there is a difference in solubility in the developer between the exposed and unexposed areas. arise. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed portion of the resist film is dissolved and removed to form a positive resist pattern, and if the resist composition is negative type, the resist film is not formed. The exposed portion is dissolved and removed to form a negative resist pattern.
In this specification, a resist composition in which an exposed portion of the resist film is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and an unexposed portion of the resist film is dissolved and removed to form a negative resist pattern. A resist composition that does this is called a negative resist composition.
The resist composition of this embodiment may be a positive resist composition or a negative resist composition.
Further, the resist composition of this embodiment may be used in an alkaline development process in which an alkaline developer is used in the development process during resist pattern formation, and a developer containing an organic solvent (organic developer) is used in the development process. It may be for a solvent development process to be used.

The resist composition of this embodiment has an acid-generating ability that generates an acid upon exposure to light, and the (A) component may generate an acid upon exposure, and the resist composition includes an additive that is blended separately from the (A) component. The components may generate acid upon exposure to light.
Specifically, the resist composition of this embodiment may contain (1) an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as "component (B)"); 2) Component (A) may be a component that generates an acid upon exposure to light, and (3) Component (A) may be a component that generates an acid upon exposure to light, and further contains the (B) component. There may be.
That is, in the cases of (2) and (3) above, the component (A) is "a base material component that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid." When component (A) is a base material component that generates an acid upon exposure and whose solubility in a developing solution changes due to the action of the acid, the component (A1) described below generates an acid upon exposure, and A polymer compound whose solubility in a developer changes due to the action of an acid is preferable. As such a polymer compound, a resin having a structural unit that generates an acid upon exposure to light can be used. As the structural unit that generates acid upon exposure to light, known units can be used.

Among the above-mentioned resist compositions, an embodiment in which the resist composition corresponds to the case (1) above, that is, the component (A) and the component (Z), and further contains the component (B) is particularly preferable.

<(A) component>
In the resist composition of this embodiment, component (A) is a base material component whose solubility in a developer changes due to the action of an acid.
In the present invention, the "base material component" is an organic compound having film-forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved, and in addition, it becomes easier to form a nano-level resist pattern.
Organic compounds used as base material components are broadly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4,000 are usually used. Hereinafter, the term "low molecular compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4,000.
As the polymer, one having a molecular weight of 1000 or more is usually used. Hereinafter, "resin", "high molecular compound", or "polymer" refers to a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, the mass average molecular weight calculated by GPC (gel permeation chromatography) in terms of polystyrene is used.

When the resist composition of the present embodiment is a "negative resist composition for alkaline development process" that forms a negative resist pattern in an alkaline development process, or "a negative resist composition for an alkaline development process" that forms a positive resist pattern in a solvent development process, Component (A) is preferably a base component (A-2) soluble in an alkaline developer (hereinafter referred to as "component (A-2)"). In addition, a crosslinking agent component is added. In such a resist composition, for example, when an acid is generated from the component (B) upon exposure, crosslinking occurs between the component (A-2) and the crosslinking agent component due to the action of the acid, and as a result, alkaline development The solubility in the developer decreases (the solubility in the organic developer increases). Therefore, when forming a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed, the exposed areas of the resist film are poorly soluble in alkaline developers (in organic developers). On the other hand, the unexposed areas of the resist film remain soluble in alkaline developers (slightly soluble in organic developers), so developing with an alkaline developer can make a negative resist A pattern is formed. Further, at this time, a positive resist pattern is formed by developing with an organic developer.
As component (A-2), a resin soluble in an alkaline developer (hereinafter referred to as "alkali-soluble resin") is preferably used.
Examples of the alkali-soluble resin include α-(hydroxyalkyl)acrylic acid or an alkyl ester of α-(hydroxyalkyl)acrylic acid (preferably having 1 to 5 carbon atoms), as disclosed in JP-A No. 2000-206694. A resin having a structural unit derived from at least one selected from alkyl esters; disclosed in US Pat. No. 6,949,325, in which the hydrogen atom bonded to the α-position carbon atom having a sulfonamide group is substituted with a substituent. Acrylic resin or polycycloolefin resin which may be Acrylic resins in which the hydrogen atoms bonded to carbon atoms may be substituted with substituents; polycycloolefin resins containing fluorinated alcohols disclosed in JP-A No. 2006-259582 have good properties with little swelling. This is preferable because a resist pattern can be formed.
The α-(hydroxyalkyl)acrylic acid is an acrylic acid in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and the α-position carbon atom bonded to the carboxy group is hydrogenated. Indicates one or both of acrylic acid to which atoms are bonded and α-hydroxyalkyl acrylic acid to which a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is bonded to the carbon atom at the α position. .
As the cross-linking agent component, it is preferable to use, for example, an amino-based cross-linking agent such as glycoluril having a methylol group or an alkoxymethyl group, or a melamine-based cross-linking agent, since a good resist pattern with little swelling is likely to be formed. . The blending amount of the crosslinking agent component is preferably 1 to 50 parts by weight per 100 parts by weight of the alkali-soluble resin.

The resist composition of the present embodiment is a "positive resist composition for alkaline development process" that forms a positive resist pattern in an alkaline development process, or a "solvent resist composition for forming a negative resist pattern in a solvent development process". Component (A) is preferably a base component (A-1) whose polarity increases due to the action of an acid (hereinafter referred to as "component (A-1)"). ) is used. By using the component (A-1), the polarity of the base material component changes before and after exposure, so that good development contrast can be obtained not only in an alkaline development process but also in a solvent development process.
When applying an alkaline development process, the component (A-1) is poorly soluble in an alkaline developer before exposure, and for example, when an acid is generated from component (B) due to exposure, the component (A-1) is Increased polarity increases solubility in alkaline developers. Therefore, when forming a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed to light, the exposed areas of the resist film change from being poorly soluble to soluble in an alkaline developer. On the other hand, since the unexposed portions of the resist film remain poorly soluble in alkali and do not change, a positive resist pattern is formed by alkali development.
On the other hand, when applying a solvent development process, the component (A-1) is highly soluble in an organic developer before exposure, and when an acid is generated from component (B) upon exposure, the effect of the acid is This increases the polarity and reduces the solubility in organic developers. Therefore, when forming a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed to light, the exposed areas of the resist film change from being soluble to slightly soluble in an organic developer. While the resist film changes, the unexposed areas of the resist film remain soluble and do not change, so by developing with an organic developer, contrast can be created between the exposed areas and the unexposed areas, and a negative resist pattern is created. It is formed.

In the resist composition of the present embodiment, one kind of component (A) may be used alone, or two or more kinds may be used in combination.
In the resist composition of this embodiment, the component (A) is preferably the component (A-1) described above. That is, the resist composition of the present embodiment is a "positive resist composition for alkaline development process" that forms a positive resist pattern in an alkaline development process, or a "solvent developable resist composition that forms a negative resist pattern in a solvent development process." A "negative resist composition for process use" is preferable. At least one of a high molecular compound and a low molecular compound can be used as the component (A).
When component (A) is component (A-1), component (A-1) preferably contains a resin component (A1) (hereinafter also referred to as "component (A1)").

- Regarding component (A1) Component (A1) is a resin component, and preferably contains a polymer compound having a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid.
In addition to the structural unit (a1), the component (A1) preferably has a structural unit (a10) containing a hydroxystyrene skeleton.
In addition to the structural unit (a1), the component (A1) also preferably has a structural unit (st) derived from styrene or a derivative thereof.
Moreover, the component (A1) may have structural units other than the structural unit (a1), the structural unit (a10), and the structural unit (st).

≪Constituent unit (a1)≫
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases under the action of an acid.
An "acid-decomposable group" is a group having acid-decomposability that allows at least a portion of the bonds in the structure of the acid-decomposable group to be cleaved by the action of an acid.
Examples of acid-decomposable groups whose polarity increases under the action of acids include groups that decompose under the action of acids to produce polar groups.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO ₃ H). Among these, a polar group containing -OH in its structure (hereinafter sometimes referred to as "OH-containing polar group") is preferred, a carboxy group or a hydroxyl group is more preferred, and a carboxy group is particularly preferred.
More specifically, the acid-decomposable group includes a group in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

Here, the term "acid-dissociable group" refers to (i) a group having acid-dissociable properties in which the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved by the action of an acid; or (ii) after some bonds are cleaved by the action of an acid, a decarboxylation reaction occurs, whereby the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group is cleaved. This refers to both of the groups that can be obtained.
The acid-dissociable group constituting the acid-dissociable group needs to be a group with lower polarity than the polar group generated by dissociation of the acid-dissociable group. When is dissociated, a polar group having higher polarity than the acid-dissociable group is generated and the polarity increases. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the relative solubility in the developer changes; when the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases. Decrease.

Examples of the acid-dissociable group include those that have been proposed as acid-dissociable groups for base resins for chemically amplified resist compositions.
Specifically, examples of acid-dissociable groups proposed as acid-dissociable groups for base resins for chemically amplified resist compositions include "acetal-type acid-dissociable groups" and "tertiary alkyl ester-type acid-dissociable groups" described below. "group" and "tertiary alkyloxycarbonylic acid dissociable group".

Acetal type acid dissociable group:
Among the polar groups, the acid-dissociable group that protects the carboxy group or hydroxyl group is, for example, an acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as an "acetal-type acid-dissociable group"). ) can be mentioned.

［式中、Ｒａ’^１、Ｒａ’^２は水素原子またはアルキル基である。Ｒａ’^３は炭化水素基であって、Ｒａ’^３は、Ｒａ’^１、Ｒａ’^２のいずれかと結合して環を形成してもよい。］

[In the formula, Ra' ¹ and Ra' ² are hydrogen atoms or alkyl groups. Ra' ³ is a hydrocarbon group, and Ra' ³ may be bonded to either Ra' ¹ or Ra' ² to form a ring. ]

In formula (a1-r-1), at least one of Ra' ¹ and Ra' ² is preferably a hydrogen atom, and more preferably both are hydrogen atoms.
When Ra' ¹ or Ra' ² is an alkyl group, the alkyl group may be one of the alkyl groups listed as substituents that may be bonded to the carbon atom at the α position in the explanation of the α-substituted acrylic ester above. Similar ones can be mentioned, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, straight-chain or branched-chain alkyl groups are preferably mentioned. More specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. More preferred, and methyl group is particularly preferred.

In formula (a1-r-1), the hydrocarbon group for Ra' ³ includes a linear or branched alkyl group, or a cyclic hydrocarbon group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, and n-pentyl group. Among these, methyl group, ethyl group or n-butyl group are preferred, and methyl group or ethyl group is more preferred.

The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, and isopropyl group is preferred.

When Ra' ³ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically Examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

When the cyclic hydrocarbon group of Ra' ³ is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.
Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms; Can be mentioned. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group in Ra' ³ is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); A group in which one hydrogen atom is removed from an aromatic compound (e.g. biphenyl, fluorene, etc.); a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., benzyl , phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc.). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon number. preferable.

The cyclic hydrocarbon group in Ra' ³ may have a substituent. Examples of this substituent include -R ^P1 , -R ^P2 -O-R ^P1 , -R ^P2 -CO-R P1 , -R ^P2 -CO- ^{OR P1 ,} -R ^P2 -O-CO-R ^P1 , -R ^P2 -OH, -R ^P2 -CN or -R ^P2 -COOH (hereinafter these substituents are also collectively referred to as "Ra ⁰⁵ "), and the like.
Here, R ^P1 is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic group having 6 to 30 carbon atoms. It is a group hydrocarbon group. R ^P2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent saturated hydrocarbon group having 6 to 30 carbon atoms. is an aromatic hydrocarbon group. However, some or all of the hydrogen atoms of the chain saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group of R ^P1 and R ^P2 may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the above substituents, or may have one or more of each of the above substituents.
Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, etc. .
Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group, etc. Monocyclic aliphatic saturated hydrocarbon group; bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl group , tetracyclo[6.2.1.13,6.02,7]dodecanyl group, adamantyl group, and other polycyclic aliphatic saturated hydrocarbon groups.
Examples of monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

When Ra' ³ is bonded to either Ra' ¹ or Ra' ² to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group, a tetrahydrofuranyl group, and the like.

Tertiary alkyl ester type acid dissociable group:
Among the above polar groups, examples of acid-dissociable groups that protect carboxy groups include acid-dissociable groups represented by the following general formula (a1-r-2).
Note that among the acid-dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups may be hereinafter referred to as "tertiary alkyl ester type acid-dissociable groups" for convenience. .

［式中、Ｒａ’^４～Ｒａ’^６はそれぞれ炭化水素基であって、Ｒａ’^５、Ｒａ’^６は互いに結合して環を形成してもよい。］

[In the formula, Ra' ⁴ to Ra' ⁶ are each a hydrocarbon group, and Ra' ⁵ and Ra' ⁶ may be bonded to each other to form a ring. ]

Examples of the hydrocarbon group for Ra' ⁴ include a linear or branched alkyl group, a chain or cyclic alkenyl group, or a cyclic hydrocarbon group.
Straight chain or branched alkyl group, cyclic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group, aromatic hydrocarbon group) in Ra' ⁴ ) is the same as Ra' ³ above.
The chain or cyclic alkenyl group for Ra' ⁴ is preferably an alkenyl group having 2 to 10 carbon atoms.
Examples of the hydrocarbon groups for Ra' ⁵ and Ra' ⁶ include the same ones as for Ra' ³ above.

When Ra' ⁵ and Ra' ⁶ combine with each other to form a ring, a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2) , groups represented by the following general formula (a1-r2-3) are preferably mentioned.
On the other hand, when Ra' ⁴ to Ra' ⁶ do not bond to each other and are independent hydrocarbon groups, groups represented by the following general formula (a1-r2-4) are preferably mentioned.

［式（ａ１－ｒ２－１）中、Ｒａ’^１０は、炭素数１～１０のアルキル基、又は下記一般式（ａ１－ｒ２－ｒ１）で表される基を示す。Ｒａ’^１１はＲａ’^１０が結合した炭素原子と共に脂肪族環式基を形成する基を示す。式（ａ１－ｒ２－２）中、Ｙａは炭素原子である。Ｘａは、Ｙａと共に環状の炭化水素基を形成する基である。この環状の炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。Ｒａ^０１～Ｒａ^０３は、それぞれ独立して、水素原子、炭素数１～１０の１価の鎖状飽和炭化水素基又は炭素数３～２０の１価の脂肪族環状飽和炭化水素基である。この鎖状飽和炭化水素基及び脂肪族環状飽和炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。Ｒａ^０１～Ｒａ^０３の２つ以上が互いに結合して環状構造を形成していてもよい。式（ａ１－ｒ２－３）中、Ｙａａは炭素原子である。Ｘａａは、Ｙａａと共に脂肪族環式基を形成する基である。Ｒａ^０４は、置換基を有していてもよい芳香族炭化水素基である。式（ａ１－ｒ２－４）中、Ｒａ’^１２及びＲａ’^１３は、それぞれ独立に、炭素数１～１０の１価の鎖状飽和炭化水素基又は水素原子である。この鎖状飽和炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。Ｒａ’^１４は、置換基を有していてもよい炭化水素基である。＊は結合手を示す（以下同じ）。］

[In formula (a1-r2-1), Ra' ¹⁰ represents an alkyl group having 1 to 10 carbon atoms or a group represented by the following general formula (a1-r2-r1). Ra' ¹¹ represents a group forming an aliphatic cyclic group together with the carbon atom to which Ra' ¹⁰ is bonded. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms possessed by this cyclic hydrocarbon group may be substituted. Ra ⁰¹ to Ra ⁰³ are each independently a hydrogen atom, a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms possessed by this chain saturated hydrocarbon group and aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra ⁰¹ to Ra ⁰³ may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra ⁰⁴ is an aromatic hydrocarbon group which may have a substituent. In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms possessed by this chain saturated hydrocarbon group may be substituted. Ra' ¹⁴ is a hydrocarbon group which may have a substituent. * indicates a bond (the same applies below). ]

［式中、Ｙａ^０は、第４級炭素原子である。Ｒａ^０３１、Ｒａ^０３２及びＲａ^０３３は、それぞれ独立に、置換基を有していてもよい炭化水素基である。但し、Ｒａ^０３１、Ｒａ^０３２及びＲａ^０３３のうちの１つ以上は、少なくとも一つの極性基を有する炭化水素基である。］

[In the formula, Ya ⁰ is a quaternary carbon atom. Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are each independently a hydrocarbon group which may have a substituent. However, one or more of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least one polar group. ]

In the above formula (a1-r2-1), the alkyl group having 1 to 10 carbon atoms in Ra' ¹⁰ is the linear or branched alkyl group in Ra' ³ in formula (a1-r-1). The groups mentioned are preferred. Ra' ¹⁰ is preferably an alkyl group having 1 to 5 carbon atoms.

In the formula (a1-r2-r1), Ya ⁰ is a quaternary carbon atom. That is, the number of adjacent carbon atoms bonded to Ya ⁰ (carbon atom) is four.

In the formula (a1-r2-r1), Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are each independently a hydrocarbon group which may have a substituent. The hydrocarbon groups in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ each independently include a linear or branched alkyl group, a chain or cyclic alkenyl group, or a cyclic hydrocarbon group.

The linear alkyl group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, and the like. Among these, methyl group, ethyl group or n-butyl group are preferred, and methyl group or ethyl group is more preferred.
The branched alkyl group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, and isopropyl group is preferred.
The chain or cyclic alkenyl group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is preferably an alkenyl group having 2 to 10 carbon atoms.

The cyclic hydrocarbon group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically Examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

The aromatic hydrocarbon group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; Can be mentioned. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specifically, the aromatic hydrocarbon group includes a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); an aromatic group containing two or more aromatic rings; A group obtained by removing one hydrogen atom from a compound (e.g. biphenyl, fluorene, etc.); a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g. benzyl group, phenethyl group) , 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc.). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon number.

When the hydrocarbon group represented by Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ above is substituted, examples of the substituent include a hydroxy group, a carboxy group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.). ), alkoxy groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), alkyloxycarbonyl group, etc.

Among the above, the hydrocarbon group which may have a substituent in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is preferably a linear or branched alkyl group which may have a substituent, Straight chain alkyl groups are more preferred.

However, one or more of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least a polar group.
"Hydrocarbon group having a polar group" refers to a hydrocarbon group in which the methylene group (-CH ₂ -) is substituted with a polar group, or a hydrocarbon group in which at least one hydrogen atom in the hydrocarbon group is substituted with a polar group. It includes all those substituted with polar groups.
The "hydrocarbon group having a polar group" is preferably a functional group represented by the following general formula (a1-p1).

［式中、Ｒａ^０７は、炭素数２～１２の２価の炭化水素基を表す。Ｒａ^０８は、ヘテロ原子を含む２価の連結基を表す。Ｒａ^０６は、炭素数１～１２の１価の炭化水素基を表す。ｎ_ｐ０は、１～６の整数である。］

[In the formula, Ra ⁰⁷ represents a divalent hydrocarbon group having 2 to 12 carbon atoms. Ra ⁰⁸ represents a divalent linking group containing a heteroatom. Ra ⁰⁶ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms. n _p0 is an integer from 1 to 6. ]

In the formula (a1-p1), Ra ⁰⁷ represents a divalent hydrocarbon group having 2 to 12 carbon atoms.
The carbon number of Ra ⁰⁷ is 2 to 12, preferably 2 to 8, more preferably 2 to 6, even more preferably 2 to 4, and particularly preferably 2.
The hydrocarbon group in Ra ⁰⁷ is preferably a chain or cyclic aliphatic hydrocarbon group, more preferably a chain hydrocarbon group.
Examples of Ra ⁰⁷ include ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1, 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, etc. Linear alkanediyl group; propane-1,2-diyl group, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, pentane-1,4-diyl group, 2 - Branched alkanediyl groups such as methylbutane-1,4-diyl group; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1 ,5-diyl group; cycloalkanediyl groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group; Examples include cyclic divalent alicyclic hydrocarbon groups.
Among the above, alkanediyl groups are preferred, and linear alkanediyl groups are more preferred.

In the formula (a1-p1), Ra ⁰⁸ represents a divalent linking group containing a heteroatom.
Ra ⁰⁸ is, for example, -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH- , -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O) ₂ -, - Examples include S(=O) ₂ -O-.
Among these, -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O- are preferred from the viewpoint of solubility in the developer, and - O-, -C(=O)- are particularly preferred.

In the formula (a1-p1), Ra ⁰⁶ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms.
The number of carbon atoms in Ra ⁰⁶ is 1 to 12, from the viewpoint of solubility in a developer, preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, even more preferably 1 to 3 carbon atoms, and 1 or 2 is particularly preferred, and 1 is most preferred.

Examples of the hydrocarbon group in Ra ⁰⁶ include a chain hydrocarbon group, a cyclic hydrocarbon group, or a combination of a chain and a cyclic hydrocarbon group.
Examples of chain hydrocarbon groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n- -heptyl group, 2-ethylhexyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group and the like.

The cyclic hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, and methyl. Examples include cycloalkyl groups such as cyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, and cyclodecyl group. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1-(adamantan-1-yl)alkan-1-yl group, norbornyl group, group, methylnorbornyl group, isobornyl group, etc.
Examples of aromatic hydrocarbon groups include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group. , biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and the like.

From the viewpoint of solubility in a developer, Ra ⁰⁶ is preferably a chain hydrocarbon group, more preferably an alkyl group, and even more preferably a linear alkyl group.

In the formula (a1-p1), n _p0 is an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1 or 2, and even more preferably 1.

Specific examples of the hydrocarbon group having at least a polar group are shown below.
In the following formula, * is a bond bonded to a quaternary carbon atom (Ya ⁰ ).

In the above formula (a1-r2-r1), among Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ , the number of hydrocarbon groups having at least a polar group is one or more, but it is difficult to add to the developer when forming a resist pattern. For example, it is preferably one or two of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ , and particularly preferably one.

The hydrocarbon group having at least a polar group may have a substituent other than the polar group. Examples of this substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.) and a halogenated alkyl group having 1 to 5 carbon atoms.

In formula (a1-r2-1), Ra' ¹¹ (the aliphatic cyclic group formed together with the carbon atom to which Ra' ¹⁰ is bonded) is the monocyclic group of Ra' ³ in formula (a1-r-1). Or the groups listed above as aliphatic hydrocarbon groups which are polycyclic groups are preferable.

In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya is a cyclic ^monovalent hydrocarbon group (aliphatic Examples include groups obtained by further removing one or more hydrogen atoms from a hydrocarbon group.
The cyclic hydrocarbon group formed by Xa and Ya may have a substituent. Examples of this substituent include the same substituents that the cyclic hydrocarbon group in Ra' ³ above may have.
In formula (a1-r2-2), examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra ⁰¹ to Ra ⁰³ include methyl group, ethyl group, propyl group, butyl group, and pentyl group. group, hexyl group, heptyl group, octyl group, decyl group, etc.
Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in Ra ⁰¹ to Ra ⁰³ include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclodecyl group. monocyclic aliphatic saturated hydrocarbon groups such as cyclododecyl group; bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1 Examples thereof include polycyclic aliphatic saturated hydrocarbon groups such as a tetracyclo[6.2.1.13,6.02,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group.
Among them, Ra ⁰¹ to Ra ⁰³ are preferably a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, from the viewpoint of ease of synthesis of the monomer compound inducing the structural unit (a1). Among these, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

Examples of the substituent of the chain saturated hydrocarbon group or aliphatic cyclic saturated hydrocarbon group represented by Ra ⁰¹ to Ra ⁰³ above include the same groups as Ra ⁰⁵ above.

Groups containing a carbon-carbon double bond formed by two or more of Ra ⁰¹ to Ra ⁰³ bonding to each other to form a cyclic structure include, for example, a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methyl Examples include a cyclohexenyl group, a cyclopentylideneethenyl group, and a cyclohexylideneethenyl group. Among these, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylideneethenyl group are preferred from the viewpoint of ease of synthesis of a monomer compound for inducing the structural unit (a1).

In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is a carbonized aliphatic group that is a monocyclic group or polycyclic group of Ra' ³ in formula (a1-r-1). The groups listed as hydrogen groups are preferred.
In formula (a1-r2-3), the aromatic hydrocarbon group for Ra ⁰⁴ includes a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among these, Ra ⁰⁴ is preferably a group in which one or more hydrogen atoms are removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, and more preferably a group in which one or more hydrogen atoms are removed from benzene, naphthalene, anthracene, or phenanthrene. , a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene is more preferable, a group obtained by removing one or more hydrogen atoms from benzene or naphthalene is particularly preferable, and a group obtained by removing one or more hydrogen atoms from benzene is most preferable. preferable.

Examples of the substituent that Ra ⁰⁴ in formula (a1-r2-3) may have include methyl group, ethyl group, propyl group, hydroxyl group, carboxyl group, halogen atom (fluorine atom, chlorine atom, (bromine atom, etc.), alkoxy groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), alkyloxycarbonyl group, etc.

In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. The monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra' ¹² and Ra' ¹³ is the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra ⁰¹ to Ra ⁰³ above. Examples include those similar to the group. Some or all of the hydrogen atoms possessed by this chain saturated hydrocarbon group may be substituted.
Ra' ¹² and Ra' ¹³ are preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, even more preferably a methyl group or an ethyl group, and a methyl group is particularly preferred. preferable.
When the chain saturated hydrocarbon group represented by Ra' ¹² and Ra' ¹³ is substituted, examples of the substituent include the same groups as Ra ⁰⁵ described above.

In formula (a1-r2-4), Ra' ¹⁴ is a hydrocarbon group that may have a substituent. The hydrocarbon group for Ra' ¹⁴ includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

The linear alkyl group in Ra' ¹⁴ preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, and the like. Among these, methyl group, ethyl group or n-butyl group are preferred, and methyl group or ethyl group is more preferred.

The branched alkyl group in Ra' ¹⁴ preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, and isopropyl group is preferred.

When Ra' ¹⁴ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically Examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

Examples of the aromatic hydrocarbon group in Ra' ¹⁴ include the same aromatic hydrocarbon groups as in Ra ⁰⁴ . Among these, Ra' ¹⁴ is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, and more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene, or phenanthrene. Preferably, a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene is more preferable, a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene is particularly preferable, and a group obtained by removing one or more hydrogen atoms from naphthalene is more preferable. Most preferred.
Examples of the substituents that Ra' ¹⁴ may have include the same substituents as the substituents that Ra ⁰⁴ may have.

When Ra' ¹⁴ in formula (a1-r2-4) is a naphthyl group, the position bonded to the tertiary carbon atom in formula (a1-r2-4) is the 1st or 2nd position of the naphthyl group. It may be either.
When Ra' ¹⁴ in formula (a1-r2-4) is an anthryl group, the position bonded to the tertiary carbon atom in formula (a1-r2-4) is the 1st, 2nd or 2nd position of the anthryl group. It can be any of the 9th place.

Specific examples of the group represented by the formula (a1-r2-1) are listed below.

Specific examples of the group represented by the above formula (a1-r2-2) are listed below.

Specific examples of the group represented by the above formula (a1-r2-3) are listed below.

Specific examples of the group represented by the above formula (a1-r2-4) are listed below.

Tertiary alkyloxycarbonylic acid dissociable group:
Among the polar groups, the acid-dissociable group that protects the hydroxyl group is, for example, an acid-dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as a "tertiary alkyloxycarbonyl acid-dissociable group" for convenience). ”) can be mentioned.

［式中、Ｒａ’^７～Ｒａ’^９はそれぞれアルキル基である。］

[In the formula, Ra' ⁷ to Ra' ⁹ are each an alkyl group. ]

In formula (a1-r-3), Ra' ⁷ to Ra' ⁹ are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms.
Further, the total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

The structural unit (a1) is a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, a structural unit derived from acrylamide, hydroxystyrene or hydroxyl. A structural unit in which at least a portion of the hydrogen atoms in the hydroxyl group of a structural unit derived from a styrene derivative is protected by a substituent containing the acid-decomposable group, a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative, - Examples include structural units in which at least a portion of the hydrogen atoms in C(=O)-OH are protected by a substituent containing the acid-decomposable group.

Among the above-mentioned structural units, structural units (a1) are preferably structural units derived from acrylic esters in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent.
Preferred specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2).

［式中、Ｒは、水素原子、炭素数１～５のアルキル基又は炭素数１～５のハロゲン化アルキル基である。Ｖａ^１は、エーテル結合を有していてもよい２価の炭化水素基である。ｎ_ａ１は、０～２の整数である。Ｒａ^１は、上記の一般式（ａ１－ｒ－１）又は（ａ１－ｒ－２）で表される酸解離性基である。Ｗａ^１はｎ_ａ２＋１価の炭化水素基であり、ｎ_ａ２は１～３の整数であり、Ｒａ^２は上記の一般式（ａ１－ｒ－１）又は（ａ１－ｒ－３）で表される酸解離性基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group which may have an ether bond. n _a1 is an integer from 0 to 2. Ra ¹ is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-2). Wa ¹ is n _a2 + monovalent hydrocarbon group, n _a2 is an integer of 1 to 3, and Ra ² is represented by the above general formula (a1-r-1) or (a1-r-3). It is an acid dissociable group. ]

In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group. , propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, with a fluorine atom being particularly preferred.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

In the formula (a1-1), the divalent hydrocarbon group in Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specifically, the aliphatic hydrocarbon group includes a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, and the like.

The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. .
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.
The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups; CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; -CH(CH ₃ )CH ₂ CH ₂ -, alkyltrimethylene groups such as -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ )CH ₂ CH ₂ -, and the like. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group in which the alicyclic hydrocarbon group is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ is a hydrocarbon group having an aromatic ring.
Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. . However, the number of carbon atoms does not include the number of carbon atoms in substituents.
Specifically, examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; Examples include aromatic heterocycles substituted with atoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group includes a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group); ) in which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group) (a group obtained by removing one hydrogen atom from an aryl group in the group), and the like. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon number.

In the formula (a1-1), Ra ¹ is an acid-dissociable group represented by the formula (a1-r-1) or (a1-r-2).

In the formula (a1-2), the n _a2 +1-valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group without aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. The aliphatic hydrocarbon group is a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a linear or branched aliphatic hydrocarbon group. Examples include groups in which a ring-containing aliphatic hydrocarbon group is combined in the structure.
The n _a2 +1 valence is preferably 2 to 4, more preferably 2 or 3.

In the above formula (a1-2), Ra ² is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

Specific examples of the structural unit represented by the above formula (a1-1) are shown below. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

Specific examples of the structural unit represented by the above formula (a1-2) are shown below.

The number of structural units (a1) contained in the component (A1) may be one or more.
As the structural unit (a1), a structural unit represented by the above formula (a1-1) is more preferable because the characteristics (sensitivity, CDU, shape, etc.) in lithography using KrF can be more easily improved.
Among these, as the structural unit (a1), one containing a structural unit represented by the following general formula (a1-1-1) is particularly preferable.

［式中、Ｒａ^１”は、一般式（ａ１－ｒ２－１）、（ａ１－ｒ２－３）又は（ａ１－ｒ２－４）で表される酸解離性基である。］

[In the formula, Ra ¹ '' is an acid-dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4).]

In the formula (a1-1-1), R, Va ¹ and n _a1 are the same as R, Va ¹ and n _a1 in the formula (a1-1).
The acid dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4) is as described above.

The proportion of the structural unit (a1) in the component (A1) is preferably 1 to 80 mol%, and 5 to 70 mol%, based on the total (100 mol%) of all the structural units constituting the component (A1). It is more preferably 10 to 60 mol%.
By setting the proportion of the structural unit (a1) to the lower limit or more, lithography properties such as sensitivity, resolution, and roughness improvement are improved. Moreover, when it is below the upper limit, it is possible to maintain a balance with other structural units, and various lithography properties become favorable.

≪Structural unit containing hydroxystyrene skeleton (a10)≫
Component (A1) preferably has a structural unit (a10) containing a hydroxystyrene skeleton in addition to the structural unit (a1).
As such a structural unit (a10), for example, a structural unit represented by the following general formula (a10-1) can be preferably mentioned.

［式中、Ｒは、水素原子、炭素数１～５のアルキル基又は炭素数１～５のハロゲン化アルキル基である。Ｙａ^ｘ１は、単結合又は２価の連結基である。Ｗａ^ｘ１は、（ｎ_ａｘ１＋１）価の芳香族炭化水素基である。ｎ_ａｘ１は、１～３の整数である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or a divalent linking group. Wa ^x1 is a (na _x1 +1)-valent aromatic hydrocarbon group. n _ax1 is an integer from 1 to 3. ]

In the formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n- Examples include butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like. The halogenated alkyl group having 1 to 5 carbon atoms for R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, with a fluorine atom being particularly preferred.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

In the formula (a10-1), Ya ^x1 is a single bond or a divalent linking group.
Suitable examples of the divalent linking group in Ya ^x1 include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

・Divalent hydrocarbon group that may have a substituent:
When Ya ^x1 is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

...Aliphatic hydrocarbon group in Ya ^x1 The aliphatic hydrocarbon group means a hydrocarbon group without aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

...Linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and The number of carbon atoms is more preferably 1 to 4, and the number of carbon atoms is most preferably 1 to 3.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.
The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups; CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; -CH(CH ₃ )CH ₂ CH ₂ -, alkyltrimethylene groups such as -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ )CH ₂ CH ₂ -, and the like. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and a carbonyl group.

...Aliphatic hydrocarbon group containing a ring in its structure The aliphatic hydrocarbon group containing a ring in its structure is a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in its ring structure. (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, Examples include groups in which a group hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those mentioned above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms. Specifically, Examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group. Most preferred are methoxy and ethoxy groups.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, with a fluorine atom being preferred.
Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms.
In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom. As the substituent containing the hetero atom, -O-, -C(=O)-O-, -S-, -S(=O) ₂ -, and -S(=O) ₂ -O- are preferable.

...Aromatic hydrocarbon group in Ya ^x1 The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; Can be mentioned. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group includes a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings; (e.g. biphenyl, fluorene, etc.) with two hydrogen atoms removed; One hydrogen atom of the group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle. is substituted with an alkylene group. (a group in which one atom is removed), and the like. The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon number.

The hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group.
Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

・Divalent linking group containing a heteroatom:
When Ya ^x1 is a divalent linking group containing a heteroatom, the linking group is preferably -O-, -C(=O)-O-, -C(=O)-, -O-C (=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)-(H may be substituted with a substituent such as an alkyl group or an acyl group) ), -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, general formula -Y ²¹ -O-Y ²² -, -Y ²¹ -O-, -Y ²¹ - C(=O)-O-, -C(=O)-O-Y ²¹ -, -[Y ²¹ -C(=O)-O] _m” -Y ²² -, -Y ²¹ -O-C( A group represented by =O)-Y ²² - or -Y ²¹ -S(=O) ₂ -O-Y ²² - [wherein Y ²¹ and Y ²² each independently have a substituent] O is an oxygen atom, and m'' is an integer from 0 to 3. ] etc.
The above divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH )-, H may be substituted with a substituent such as an alkyl group or acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
General formula -Y ²¹ -O-Y ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-O-Y ²¹ -, -[Y ²¹ - C(=O)-O] _m” -Y ²² -, -Y ²¹ -O-C(=O)-Y ²² - or -Y ²¹ -S(=O) ₂ -O-Y ²² -, Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include those mentioned in the description of the divalent linking group above. (divalent hydrocarbon group which may have a substituent).
^Y21 is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, even more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly a methylene group or an ethylene group. preferable.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, and more preferably a methylene group, ethylene group or alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula -[Y ²¹ -C(=O)-O] _m" -Y ²² -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, and 0 or 1 is more preferred, and 1 is particularly preferred. In other words, as a group represented by the formula -[Y ²¹ -C(=O)-O] _m'' -Y ²² -, a group represented by the formula -Y ²¹ -C(=O)-O-Y ²² - A group is particularly preferred. Among these, a group represented by the formula -(CH ₂ ) _a' -C(=O)-O-(CH ₂ ) _b' - is preferred. In the formula, a' is 1 to 10 b' is an integer of 1 to 8, preferably an integer of 1 to 8, more preferably 1 to 5, even more preferably 1 or 2, and most preferably 1.b' is an integer of 1 to 10, preferably 1 to 8. An integer is preferred, an integer from 1 to 5 is more preferred, 1 or 2 is even more preferred, and 1 is most preferred.

Ya ^x1 is a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), -C(=O)-NH-, or a linear or branched alkylene group. , or a combination thereof, with single bonds being particularly preferred.

In the formula (a10-1), Wa ^x1 is a (n _ax1 +1)-valent aromatic hydrocarbon group.
Examples of the aromatic hydrocarbon group in Wa ^x1 include a group obtained by removing (na _x1 +1) hydrogen atoms from an aromatic ring. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; Can be mentioned. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

In the formula (a10-1), n _ax1 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.

Specific examples of the structural unit represented by the general formula (a10-1) are shown below.
In the following formula, R ^α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

The number of structural units (a10) contained in the component (A1) may be one type or two or more types.
In component (A1), the proportion of the structural unit (a10) is, for example, 1 to 90 mol%, and 10 to 85 The amount is preferably mol%, more preferably 20 to 80 mol%, and particularly preferably 30 to 75 mol%.
By setting the proportion of the structural unit (a10) to the lower limit of the above-mentioned preferable range or more, lithography properties such as sensitivity, resolution, and roughness improvement are improved. Moreover, when it is below the upper limit, it is possible to maintain a balance with other structural units, and various lithography properties become favorable.

≪Constituent unit (a2)≫
In addition to the structural unit (a1), the component (A1) further contains a structural unit (a2) containing a lactone-containing cyclic group, a -SO ₂ --containing cyclic group, or a carbonate-containing cyclic group (provided that the structural unit ( (excluding those falling under a1)).
The lactone-containing cyclic group, -SO ₂ --containing cyclic group, or carbonate-containing cyclic group of the structural unit (a2) is important for the adhesion of the resist film to the substrate when the component (A1) is used to form the resist film. It is effective in increasing sexuality. In addition, by having the structural unit (a2), for example, the acid diffusion length can be appropriately adjusted, the adhesion of the resist film to the substrate can be increased, and the solubility during development can be appropriately adjusted, so that the lithography properties can be improved. etc. will be good.

The term "lactone-containing cyclic group" refers to a cyclic group containing a ring containing -OC(=O)- (lactone ring) in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, and when it has other ring structures, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any arbitrary group can be used. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be mentioned.

［式中、Ｒａ’^２１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、－ＣＯＯＲ”、－ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は－ＳＯ_２－含有環式基であり；Ａ”は酸素原子（－Ｏ－）もしくは硫黄原子（－Ｓ－）を含んでいてもよい炭素数１～５のアルキレン基、酸素原子または硫黄原子であり、ｎ’は０～２の整数であり、ｍ’は０または１である。］

[In the formula, Ra' ²¹ is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group. Yes; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO ₂ --containing cyclic group; A" is an oxygen atom (-O-) or a sulfur atom (- S-) is an alkylene group having 1 to 5 carbon atoms, an oxygen atom, or a sulfur atom, n' is an integer of 0 to 2, and m' is 0 or 1. ]

In the general formulas (a2-r-1) to (a2-r-7), the alkyl group at Ra' ²¹ is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, and the like. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred.
The alkoxy group for Ra' ²¹ is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, a group in which the alkyl group mentioned above as the alkyl group in Ra' ²¹ and an oxygen atom (-O-) are connected can be mentioned.
Examples of the halogen atom in Ra' ²¹ include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, with a fluorine atom being preferred.
Examples of the halogenated alkyl group at Ra' ²¹ include groups in which part or all of the hydrogen atoms of the alkyl group at Ra' ²¹ are substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In -COOR'' and -OC(=O)R'' in Ra' ²¹ , R'' is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -SO ₂ -containing cyclic group. It is.
The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms.
When R'' is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R'' is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms.Specifically, fluorine atom or a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorinated alkyl group; polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes Examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane and cyclohexane; adamantane, norbornane, isobornane, tri- Examples include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as cyclodecane and tetracyclododecane.
Examples of the lactone-containing cyclic group in R'' include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7).
The carbonate-containing cyclic group in R'' is the same as the carbonate-containing cyclic group described below, and specifically, groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. can be mentioned.
The -SO ₂ --containing cyclic group in R'' is the same as the -SO ₂ --containing cyclic group described below, and specifically, general formulas (a5-r-1) to (a5-r-4) Examples include groups represented by the following.
The hydroxyalkyl group in Ra' ²¹ preferably has 1 to 6 carbon atoms, and specifically includes a group in which at least one hydrogen atom of the alkyl group in Ra' ²¹ is substituted with a hydroxyl group. .

In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A'' is a linear or branched alkylene group. Alkylene groups are preferred, and include methylene groups, ethylene groups, n-propylene groups, isopropylene groups, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples include the terminal or carbon atoms of the alkylene group. Examples include groups in which -O- or -S- exists between atoms, such as -O-CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH _2- , etc.A'' is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

Specific examples of groups represented by general formulas (a2-r-1) to (a2-r-7) are listed below.

"-SO ₂ --containing cyclic group" refers to a cyclic group containing a ring containing -SO ₂ - in its ring skeleton, and specifically, the sulfur atom (S) in -SO ₂ - A cyclic group that forms part of the ring skeleton of a cyclic group. A ring containing -SO ₂ - in its ring skeleton is counted as the first ring, and if this ring only exists, it is a monocyclic group, and if it has other ring structures, it is a polycyclic group regardless of the structure. It is called. The -SO ₂ --containing cyclic group may be a monocyclic group or a polycyclic group.
-SO ₂ --containing cyclic group is particularly a cyclic group containing -O-SO ₂ - in its ring skeleton, that is, -O-S- in -O-SO ₂ - forms part of the ring skeleton. Preferably, it is a cyclic group containing a sultone ring.
More specific examples of the -SO ₂ --containing cyclic group include groups represented by the following general formulas (a5-r-1) to (a5-r-4), respectively.

［式中、Ｒａ’^５１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、－ＣＯＯＲ”、－ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は－ＳＯ_２－含有環式基であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１～５のアルキレン基、酸素原子または硫黄原子であり、ｎ’は０～２の整数である。］

[In the formula, Ra' ⁵¹ is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group. Yes; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO ₂ --containing cyclic group; A" is a carbon that may contain an oxygen atom or a sulfur atom It is an alkylene group of number 1 to 5, an oxygen atom or a sulfur atom, and n' is an integer of 0 to 2. ]

In the general formulas (a5-r-1) to (a5-r-2), A'' is the general formula (a2-r-2), (a2-r-3), (a2-r-5) It is the same as "A" in the middle.
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in Ra' ⁵¹ are represented by the above general formulas (a2-r-1) to ( The same compounds as those mentioned in the explanation of Ra' ²¹ in a2-r-7) can be mentioned.
Specific examples of groups represented by general formulas (a5-r-1) to (a5-r-4) are listed below. "Ac" in the formula represents an acetyl group.

The term "carbonate-containing cyclic group" refers to a cyclic group containing a ring containing -OC(=O)-O- (carbonate ring) in its ring skeleton. The carbonate ring is counted as the first ring, and when it has only a carbonate ring, it is called a monocyclic group, and when it has other ring structures, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
Any carbonate ring-containing cyclic group can be used without particular limitation. Specifically, groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) can be mentioned.

［式中、Ｒａ’^ｘ３１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、－ＣＯＯＲ”、－ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は－ＳＯ_２－含有環式基であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１～５のアルキレン基、酸素原子または硫黄原子であり、ｐ’は０～３の整数であり、ｑ’は０または１である。］

[In the ^formula , Ra'Yes;R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO ₂ --containing cyclic group; A" is a carbon that may contain an oxygen atom or a sulfur atom It is an alkylene group of number 1 to 5, an oxygen atom or a sulfur atom, p' is an integer of 0 to 3, and q' is 0 or 1. ]

In the general formulas (ax3-r-2) to (ax3-r-3), A'' is the general formula (a2-r-2), (a2-r-3), (a2-r-5) It is the same as "A" in the middle.
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in Ra' ³¹ are represented by the above general formulas (a2-r-1) to ( The same compounds as those mentioned in the explanation of Ra' ²¹ in a2-r-7) can be mentioned.
Specific examples of the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) are listed below.

Among these, the structural unit (a2) is preferably a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent.
The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

［式中、Ｒは水素原子、炭素数１～５のアルキル基又は炭素数１～５のハロゲン化アルキル基である。Ｙａ^２１は単結合または２価の連結基である。Ｌａ^２１は－Ｏ－、－ＣＯＯ－、－ＣＯＮ（Ｒ’）－、－ＯＣＯ－、－ＣＯＮＨＣＯ－又は－ＣＯＮＨＣＳ－であり、Ｒ’は水素原子またはメチル基を示す。ただしＬａ^２１が－Ｏ－の場合、Ｙａ^２１は－ＣＯ－にはならない。Ｒａ^２１はラクトン含有環式基、カーボネート含有環式基、又は－ＳＯ_２－含有環式基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ²¹ is a single bond or a divalent linking group. La ²¹ is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, and R' represents a hydrogen atom or a methyl group. However, when La ²¹ is -O-, Ya ²¹ does not become -CO-. Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO ₂ -containing cyclic group. ]

In the formula (a2-1), R is the same as above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferred.

In the above formula (a2-1), the divalent linking group of Ya ²¹ is not particularly limited, but includes a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, etc. etc. are preferably mentioned. The explanation about the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom in ^{Ya 21 is} as follows: The explanations are the same as for the divalent hydrocarbon group which may have a group and the divalent linking group containing a hetero atom.
Ya ²¹ is preferably a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof. .

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group, a -SO ₂ --containing cyclic group, or a carbonate-containing cyclic group.
The lactone-containing cyclic group, -SO ₂ --containing cyclic group, and carbonate-containing cyclic group in Ra ²¹ are each represented by the aforementioned general formulas (a2-r-1) to (a2-r-7), respectively. groups represented by general formulas (a5-r-1) to (a5-r-4), groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. are preferably mentioned.
Among these, lactone-containing cyclic groups or -SO ₂ --containing cyclic groups are preferred, and those of the general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r The groups represented by -1) are more preferred. Specifically, the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r- More preferred are any of the groups represented by lc-6-1), (r-sl-1-1), and (r-sl-1-18), respectively.

The number of structural units (a2) contained in the component (A1) may be one or more.
When the component (A1) has a structural unit (a2), the proportion of the structural unit (a2) is 0 to 50 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). It is preferably 5 to 45 mol%, even more preferably 10 to 40 mol%, and particularly preferably 10 to 30 mol%.
By setting the ratio of the structural unit (a2) to a preferable lower limit or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the ratio to the upper limit or less, a balance with other structural units can be achieved. This results in improved various lithography properties.

≪Constituent unit (a3)≫
In addition to the structural unit (a1), the component (A1) is a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group (provided that the structural unit (a1) and the structural unit (a2) ). When the component (A1) has the structural unit (a3), it can, for example, appropriately adjust the acid diffusion length, increase the adhesion of the resist film to the substrate, appropriately adjust the solubility during development, and improve etching resistance. Due to the effect of improving the lithography characteristics, etc., the lithography characteristics become better.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which some of the hydrogen atoms of an alkyl group are substituted with fluorine atoms, with the hydroxyl group being particularly preferred.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and can be appropriately selected from among a large number of groups proposed for use in, for example, resins for resist compositions for ArF excimer lasers. The cyclic group is preferably a polycyclic group, and more preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylic ester containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. is more preferable. Examples of the polycyclic group include groups obtained by removing two or more hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, and the like. Specifically, examples thereof include groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups obtained by removing two or more hydrogen atoms from adamantane, groups obtained by removing two or more hydrogen atoms from norbornane, and groups obtained by removing two or more hydrogen atoms from tetracyclododecane. Industrially preferred.

As the structural unit (a3), any unit can be used without particular limitation as long as it contains a polar group-containing aliphatic hydrocarbon group.
The structural unit (a3) is a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and includes a polar group-containing aliphatic hydrocarbon group. Constituent units are preferred.
When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the structural unit (a3) may be derived from hydroxyethyl ester of acrylic acid. Preferably, the structural unit is
Further, as the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the formula (a3 Preferred examples include the structural unit represented by -2) and the structural unit represented by formula (a3-3).

［式中、Ｒは前記と同じであり、ｊは１～３の整数であり、ｋは１～３の整数であり、ｔ’は１～３の整数であり、ｌは１～５の整数であり、ｓは１～３の整数である。］

[In the formula, R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, and l is an integer of 1 to 5. and s is an integer from 1 to 3. ]

In formula (a3-1), j is preferably 1 or 2, more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
It is preferable that j is 1, and it is particularly preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

In formula (a3-3), t' is preferably 1. It is preferable that l is 1. Preferably, s is 1. In these, it is preferable that a 2-norbornyl group or a 3-norbornyl group is bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5 or 6 position of the norbornyl group.

The structural unit (a3) contained in the component (A1) may be one type or two or more types.
When component (A1) has a structural unit (a3), it is preferably 1 to 40 mol%, more preferably 2 to 30 mol%, based on the total of all structural units constituting component (A1), It is more preferably 5 to 25 mol%, particularly preferably 5 to 20 mol%.
By setting the ratio of the structural unit (a3) to a preferable lower limit or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting the ratio to the upper limit or less, a balance with other structural units can be achieved. This results in improved various lithography properties.

≪Constituent unit (st)≫
In addition to the structural unit (a1), the component (A1) may further have a structural unit (st) derived from styrene or a derivative thereof. The term "styrene" includes styrene and styrene in which the hydrogen atom at the α-position is substituted with a substituent such as an alkyl group or a halogenated alkyl group. Examples of the alkyl group as a substituent here include an alkyl group having 1 to 5 carbon atoms, and examples of the halogenated alkyl group as the substituent include a halogenated alkyl group having 1 to 5 carbon atoms.
Examples of the "styrene derivative" include those in which a substituent is bonded to the benzene ring of styrene, in which the hydrogen atom at the α-position may be substituted with a substituent.
Note that the α-position (α-position carbon atom) refers to a carbon atom to which a benzene ring is bonded, unless otherwise specified.
"Structural unit derived from styrene" and "structural unit derived from styrene derivative" refer to a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.
The structural unit (st) contained in the component (A1) may be one type or two or more types.
When the component (A1) has a structural unit (st), the proportion of the structural unit (st) is 1 to 50 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). It is preferably 3 to 40 mol%, more preferably 3 to 40 mol%.

≪Other constituent units≫
The component (A1) may have other structural units other than the above-mentioned structural unit (a1), structural unit (a10), structural unit (a2), structural unit (a3), and structural unit (st).
Other structural units include, for example, the structural unit (a9) represented by the general formula (a9-1) described below, the structural unit derived from styrene, the structural unit derived from a styrene derivative (however, the structural unit (a10) ), structural units containing non-acid-dissociable aliphatic cyclic groups, etc.

Constituent unit (a9):
The structural unit (a9) is a structural unit represented by the following general formula (a9-1).

［式中、Ｒは、水素原子、炭素数１～５のアルキル基又は炭素数１～５のハロゲン化アルキル基である。Ｙａ^９１は、単結合又は２価の連結基である。Ｙａ^９２は、２価の連結基である。Ｒ^９１は、置換基を有していてもよい炭化水素基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ⁹¹ is a single bond or a divalent linking group. Ya ⁹² is a divalent linking group. R ⁹¹ is a hydrocarbon group that may have a substituent. ]

In the formula (a9-1), R is the same as above.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is particularly preferable from the viewpoint of industrial availability.

In the above formula (a9-1), the divalent linking group in Ya ⁹¹ is the same as the divalent linking group in Ya ^x1 in the above-mentioned general formula (a10-1). Among these, Ya ⁹¹ is preferably a single bond.

In the above formula (a9-1), the divalent linking group at Ya ⁹² may be the same as the divalent linking group at Ya ^x1 in the above-mentioned general formula (a10-1).
In the divalent linking group in Ya ⁹² , the divalent hydrocarbon group which may have a substituent is preferably a linear or branched aliphatic hydrocarbon group.
In addition, among the divalent linking groups in Ya ⁹² , divalent linking groups containing a hetero atom include -O-, -C(=O)-O-, -C(=O)-, -O-C (=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)-(H may be substituted with a substituent such as an alkyl group or an acyl group) ), -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, -C(=S)-, general formula -Y ²¹ -O-Y ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-O--Y ²¹ , [Y ²¹ -C(=O)-O] _m' -Y ²² - or - A group represented by Y ²¹ -O-C(=O)-Y ²² - [wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent; , O is an oxygen atom, and m' is an integer from 0 to 3. ] etc. Among these, -C(=O)- and -C(=S)- are preferred.

In the formula (a9-1), examples of the hydrocarbon group for R ⁹¹ include an alkyl group, a monovalent alicyclic hydrocarbon group, an aryl group, an aralkyl group, and the like.
The alkyl group in R ⁹¹ preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and may be linear or branched. Specifically, preferred examples include methyl group, ethyl group, propyl group, butyl group, hexyl group, and octyl group.
The monovalent alicyclic hydrocarbon group for R ⁹¹ preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms, and may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclobutane, cyclopentane, and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms. Specifically, Examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The aryl group in R ⁹¹ preferably has 6 to 18 carbon atoms, more preferably 6 to 10 carbon atoms, and specifically, phenyl group is particularly preferable.
The aralkyl group for R ⁹¹ is preferably an aralkyl group in which an alkylene group having 1 to 8 carbon atoms and the above "aryl group in R ⁹¹ " are bonded, and an alkylene group having 1 to 6 carbon atoms and the above "aryl group in R ⁹¹ " are bonded. is more preferable, and an aralkyl group in which an alkylene group having 1 to 4 carbon atoms is bonded to the above-mentioned "aryl group in R ⁹¹ " is particularly preferable.
In the hydrocarbon group in R ⁹¹ , it is preferable that some or all of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms. It is more preferable that Among these, a perfluoroalkyl group in which all of the hydrogen atoms of the alkyl group mentioned above are substituted with fluorine atoms is particularly preferable.

The hydrocarbon group for R ⁹¹ may have a substituent. Examples of the substituent include a halogen atom, an oxo group (=O), a hydroxyl group (-OH), an amino group (-NH ₂ ), and -SO ₂ -NH ₂ . Further, some of the carbon atoms constituting the hydrocarbon group may be substituted with a substituent containing a hetero atom. Examples of substituents containing heteroatoms include -O-, -NH-, -N=, -C(=O)-O-, -S-, -S(=O) ₂ -, -S(=O ) ₂ -O-.
In R ⁹¹ , examples of the hydrocarbon group having a substituent include lactone-containing cyclic groups represented by the above general formulas (a2-r-1) to (a2-r-7), respectively.

In addition, in R ⁹¹ , the hydrocarbon group having a substituent is an -SO ₂ -containing cyclic group represented by each of the above general formulas (a5-r-1) to (a5-r-4); Also included are substituted aryl groups and monovalent heterocyclic groups represented by chemical formulas.

Among the structural units (a9), structural units represented by the following general formula (a9-1-1) are preferred.

［式中、Ｒは前記と同様であり、Ｙａ^９１は単結合または２価の連結基であり、Ｒ^９１は置換基を有していてもよい炭化水素基であり、Ｒ^９２は酸素原子又は硫黄原子である。］

[In the formula, R is the same as above, Ya ⁹¹ is a single bond or a divalent linking group, R ⁹¹ is a hydrocarbon group that may have a substituent, and R ⁹² is an oxygen atom or It is a sulfur atom. ]

In general formula (a9-1-1), the explanations for Ya ⁹¹ , R ⁹¹ and R are the same as above. Further, R ⁹² is an oxygen atom or a sulfur atom.

Specific examples of the structural unit represented by the above formula (a9-1) or general formula (a9-1-1) are shown below. In the following formula, R ^α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

Component (A1) may contain one type of structural unit (a9) or two or more types.
When the component (A1) has a structural unit (a9), the proportion of the structural unit (a9) is 1 to 40 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). It is preferably 3 to 30 mol%, even more preferably 5 to 25 mol%, and particularly preferably 10 to 20 mol%.
By setting the ratio of the structural unit (a9) to the lower limit or more, for example, the acid diffusion length can be appropriately adjusted, the adhesion of the resist film to the substrate can be increased, the solubility during development can be appropriately adjusted, and the etching resistance can be improved. If the content is below the upper limit, a balance with other structural units can be achieved and various lithography properties will be improved.

Constituent unit (a4):
The structural unit (a4) is a structural unit containing an acid non-dissociable aliphatic cyclic group. In addition to the structural unit (a1), the component (A1) may further include a structural unit (a4).
When the component (A1) has the structural unit (a4), the dry etching resistance of the resist pattern to be formed is improved. Moreover, the hydrophobicity of component (A) increases. Improvement in hydrophobicity is considered to contribute to improvement in resolution, resist pattern shape, etc., especially in the case of a solvent development process.
The "acid non-dissociable cyclic group" in the structural unit (a4) is a non-acid dissociable cyclic group that is used when an acid is generated in the resist composition due to exposure (for example, when an acid is generated from component (B) described below). It is a cyclic group that remains in the structural unit without dissociating even if acted upon by
The structural unit (a4) is preferably a structural unit derived from an acrylic ester containing an acid-nondissociable aliphatic cyclic group. As the cyclic group, a large number of those conventionally known as those used in resin components of resist compositions for ArF excimer lasers, KrF excimer lasers (preferably ArF excimer lasers), etc. can be used. .
In particular, at least one selected from tricyclodecyl, adamantyl, tetracyclododecyl, isobornyl, and norbornyl groups is preferred from the standpoint of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include structural units represented by the following general formulas (a4-1) to (a4-7).

［式中、Ｒ^αは前記と同じである。］

[In the formula, R ^α is the same as above. ]

The structural unit (a4) contained in the component (A1) may be one type or two or more types.
When the component (A1) has a structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all structural units constituting the component (A1), More preferably 3 to 20 mol%.
By setting the ratio of the structural unit (a4) to a preferable lower limit or more, the effect of containing the structural unit (a4) can be sufficiently obtained, while by setting the ratio to a preferable upper limit or less, it can be combined with other structural units. It becomes easier to balance.

The component (A1) contained in the resist composition may be used alone or in combination of two or more.
Component (A1) preferably contains a polymer compound (A1-1) having a structural unit (a1) (hereinafter also referred to as "component (A1-1)").
Preferred component (A1-1) is, for example, a polymer compound having a repeating structure of the structural unit (a1) and the structural unit (a10), or a polymer compound having a repeating structure of the structural unit (a1) and the structural unit (st). Examples include polymer compounds.
In addition to the combination of the two structural units described above, the structural units described above may be combined as a third or three or more structural units as appropriate to achieve a desired effect. Examples of the combination of three or more structural units include a combination of a structural unit (a1), a structural unit (a10), and a structural unit (st).

Component (A1) is prepared by dissolving monomers for inducing each structural unit in a polymerization solvent, and initiating radical polymerization of, for example, azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (for example, V-601, etc.). It can be manufactured by adding an agent and polymerizing it. Alternatively, the component (A1) may include a monomer that induces the structural unit (a1) and, if necessary, a precursor of a monomer that induces a structural unit other than the structural unit (a1) (the functional group of the monomer is protected). It can be produced by dissolving a monomer) in a polymerization solvent, adding thereto a radical polymerization initiator as described above for polymerization, and then performing a deprotection reaction. In addition, during polymerization, for example, by using a chain transfer agent such as HS-CH ₂ -CH ₂ -CH ₂ -C(CF ₃ ) ₂ -OH in combination, -C(CF ₃ ) is added to the terminal. ₂ -OH group may be introduced. In this way, a copolymer into which a hydroxyalkyl group is introduced in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms can reduce development defects and reduce LER (line edge roughness: unevenness of line sidewalls). It is effective in reducing

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard determined by gel permeation chromatography (GPC)) is not particularly limited, and is preferably from 1,000 to 50,000, more preferably from 2,000 to 30,000, and from 3,000 to 20,000 is more preferable.
When the Mw of component (A1) is below the preferable upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is above the preferable lower limit of this range, it has good dry etching resistance. The cross-sectional shape of the resist pattern is good.
The degree of dispersion (Mw/Mn) of component (A1) is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, particularly preferably 1.1 to 2.0. . In addition, Mn indicates a number average molecular weight.

・About the (A2) component The resist composition of the present embodiment contains, as the (A) component, a base material component (hereinafter referred to as "(A2) ) may be used in combination.
The component (A2) is not particularly limited, and may be arbitrarily selected from a large number of components conventionally known as base components for chemically amplified resist compositions.
As the component (A2), one type of high molecular compound or low molecular compound may be used alone, or two or more types may be used in combination.

The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and 100% by mass, based on the total mass of component (A). It may be. When the proportion is 25% by mass or more, a resist pattern that is excellent in various lithography properties such as high sensitivity, resolution, and roughness improvement is easily formed.

<(Z) component>
In the resist composition of this embodiment, component (Z) is a dissolution inhibitor that suppresses solubility in a developer.
Component (Z) is a compound (Z1) having a mass average molecular weight of 3000 or less and having a phenolic hydroxyl group or carboxyl group in the molecule (hereinafter also referred to as "(Z1) component"), and a compound (Z1) having a mass average molecular weight of 3000 or less. and a compound (Z2) (hereinafter also referred to as "component (Z2)") represented by the general formula (z2) described below.

- Regarding component (Z1) Component (Z1) is not particularly limited as long as it is a compound having a mass average molecular weight of 3000 or less and having a phenolic hydroxyl group or carboxyl group in the molecule.
The mass average molecular weight of component (Z1) is preferably 150 to 3,000, more preferably 200 to 2,500, and still more preferably 250 to 2,000.
When the mass average molecular weight of the component (Z1) is at least the lower limit of the above-mentioned preferred range, the adhesion performance to the substrate is improved.

As component (Z1), a compound represented by the following general formula (z1-1) or (z1-2) is preferable.

［式（ｚ１－１）中、Ｖ_ｚ ^１は２価の連結基である。ｎ１１及びｎ１２は、それぞれ独立に、１～３の整数である。式（ｚ１－２）中、Ｒｚ^２は、炭化水素基である。ｎ２１は１又は２である。ｎ２２は２～５の整数である。ただし、ｎ２１＋ｎ２２≦６である。］

[In formula (z1-1), V _z ¹ is a divalent linking group . n11 and n12 are each independently an integer of 1 to 3. In formula (z 1 - 2 ), Rz ² is a hydrocarbon group. n21 is 1 or 2. n22 is an integer from 2 to 5. However, n21+n22≦6. ]

In the above formula (z1-1), the divalent linking group for V _z ¹ includes the same divalent linking group as the divalent linking group for Ya ^x1 in the above-mentioned general formula (a10-1). Further, as the divalent linking group of V _z ¹ , a linear or branched aliphatic hydrocarbon group is used as the divalent linking group of Ya ^x1 in the above-mentioned general formula (a10-1). Also included are groups in which some of the hydrogen atoms are substituted with aromatic hydrocarbon groups.

The linear or branched aliphatic hydrocarbon group in "a group in which some of the hydrogen atoms constituting the linear or branched aliphatic hydrocarbon group are substituted with an aromatic hydrocarbon group" , methylene group [-CH ₂ -], ethylene group [-(CH ₂ ) ₂ -], -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, - Examples include alkylmethylene groups such as C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, and -C(CH ₂ CH ₃ ) ₂ -.
Examples of aromatic hydrocarbon groups in "a straight-chain or branched aliphatic hydrocarbon group in which some of the hydrogen atoms are substituted with an aromatic hydrocarbon group" include benzene, fluorene, naphthalene, anthracene, etc. , phenanthrene, biphenyl, and other groups in which one hydrogen atom is removed from an aromatic ring.
The aromatic hydrocarbon group in "a straight-chain or branched aliphatic hydrocarbon group in which some of the hydrogen atoms are substituted with an aromatic hydrocarbon group" may have a substituent. good. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an arylalkyl group, and the like.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group.
Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include the hydrogen atom possessed by the cyclic aliphatic hydrocarbon group in the divalent linking group of Ya ^x1 in the general formula (a10-1) described above. Examples of the substituent for substituting .
Examples of the arylalkyl group as the substituent include benzyl group, phenethyl group, phenyl-t-butyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc. It will be done. The arylalkyl group may have a substituent such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or an arylalkyl group.

The compound represented by the formula (z1-1) is preferably a compound represented by the following general formula (z1-1-1).

［式中、Ｒ_ｚ ^１１及びＲ_ｚ ^１２は、それぞれ独立して、水素原子又は置換基を有してもよい炭化水素基である。Ｒ_ｚ ^１１及びＲ_ｚ ^１２は、相互に結合して環を形成してもよい。ｎ１１及びｎ１２は、それぞれ独立に、１～３の整数である。］

[In the formula, R _z ¹¹ and R _z ¹² are each independently a hydrogen atom or a hydrocarbon group which may have a substituent. R _z ¹¹ and R _z ¹² may be bonded to each other to form a ring. n11 and n12 are each independently an integer of 1 to 3. ]

In the above formula (z1-1-1), the hydrocarbon groups for R _z ¹¹ and R _z ¹² include a linear or branched alkyl group, an aromatic hydrocarbon group which may have a substituent, etc. can be mentioned.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, and the like. Among these, methyl group, ethyl group or n-butyl group are preferred, and methyl group or ethyl group is more preferred.
The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, and isopropyl group is preferred.

Examples of the aromatic hydrocarbon group for R _z ¹¹ and R _z ¹² include groups obtained by removing one hydrogen atom from an aromatic ring such as benzene, fluorene, naphthalene, anthracene, phenanthrene, and biphenyl.
The aromatic hydrocarbon group in R _z ¹¹ and R _z ¹² may have a substituent. As the substituent, the aromatic hydrocarbon group in the above-mentioned "group in which a part of the hydrogen atoms constituting the linear or branched aliphatic hydrocarbon group is substituted with an aromatic hydrocarbon group" is used. The same applies to the substituents that may be used.

In the formula (z1-1-1), R _z ¹¹ and R _z ¹² may be bonded to each other to form a ring. Examples of the ring formed include aliphatic rings such as a cyclopentane ring, a cyclohexane ring, and a cycloheptane ring.

In the formula (z1-1-1), R _z ¹¹ and R _z ¹² are a linear alkyl group having 1 to 5 carbon atoms or an aromatic hydrocarbon group which may have a substituent, Alternatively, R _z ¹¹ and R _z ¹² are preferably bonded to each other to form an aliphatic ring, and are a methyl group, a phenyl group, or a 4-(4-hydroxyphenyl-t-butyl) phenyl group, Alternatively, it is more preferable that R _z ¹¹ and R _z ¹² are bonded to each other to form a cyclopentane ring.

In the above formula (z1-2), examples of the hydrocarbon group for Rz ² include those exemplified as the hydrocarbon groups for R _z ¹¹ and R _z ¹² in the above formula (z1-1-1). Among these, Rz ² is preferably an aromatic hydrocarbon group, more preferably a phenyl group or a benzyl group, and even more preferably a phenyl group.
In the formula (z1-2), n21 is 1 or 2, preferably 1. n22 is an integer of 2 to 5, preferably 2 or 3, and more preferably 2.

The compound represented by the formula (z1-2) is preferably a compound represented by the following general formula (z1-2-1).

［式中、Ｒｚ^２１及びＲｚ^２２は、それぞれ独立に、芳香族炭化水素基である。］

[In the formula, Rz ²¹ and Rz ²² are each independently an aromatic hydrocarbon group. ]

In the above formula (z1-2-1), examples of the hydrocarbon group for Rz ² include those exemplified as the hydrocarbon groups for R _z ¹¹ and R _z ¹² in the above formula (z1-1-1). Among these, Rz ² is preferably a phenyl group or a benzyl group, and more preferably a phenyl group.

Specific examples of component (Z1) are listed below.

Other specific examples of component (Z1) include the compounds described in paragraph [0158] of JP-A-2008-122932, and the compounds described in paragraphs [0036]-[0055] of JP-A-10-097075. Examples include compounds that are

The component (Z1) contained in the resist composition may be used alone or in combination of two or more.

- Regarding component (Z2) Component (Z2) is a compound having a mass average molecular weight of 3000 or less and represented by the following general formula (z2).

［式中、Ｒ_ｚ ^２０は酸解離性基である。Ｒ_ｚ ^３０は水素原子又は有機基である。ｎ１は１～６の整数であり、ｎ２は０～５の整数である。ただし、ｎ１＋ｎ２＝６である。］

[In the formula, R _z ²⁰ is an acid dissociable group. R _z ³⁰ is a hydrogen atom or an organic group. n1 is an integer from 1 to 6, and n2 is an integer from 0 to 5. However, n1+n2=6. ]

The mass average molecular weight of component (Z2) is preferably 150 to 3,000, more preferably 200 to 2,500, and still more preferably 250 to 2,000.
When the mass average molecular weight of the component (Z2) is within the above-mentioned preferred range, the amount of resist film slippage made of the radiation-sensitive resin composition can be reduced.

In the formula (z2), examples of the acid dissociable group for R _z ²⁰ include groups represented by the following general formulas (z2-r-1) to (z2-r-4).

［式中、Ｒ_ｚ ^２０１～Ｒ_ｚ ^２０６は、それぞれ独立に、直鎖状又は分枝状のアルキル基、直鎖状又は分枝状のアルコキシ基、直鎖状又は分枝状のアルコキシアルキル基、直鎖状又は分枝状のアルケニル基、又はアリール基であり、これら基は鎖中にカルボニル基を含んでいてもよい。あるいは、Ｒ_ｚ ^２０１とＲ_ｚ ^２０２、Ｒ_ｚ ^２０４とＲ_ｚ ^２０５は互いに結合して環を形成していてもよい。Ｒ_ｚ ^２０７及びＲ_ｚ ^２０８は、それぞれ独立に、水素原子、直鎖状又は分枝状のアルキル基、直鎖状又は分枝状のアルコキシ基、直鎖状又は分枝状のアルコキシアルキル基、直鎖状又は分枝状のアルケニル基、又はアリール基である。Ｒ_ｚ ^２０９は、直鎖状又は分枝状のアルキル基、直鎖状又は分枝状のアルコキシアルキル基、直鎖状又は分枝状のアルケニル基、又はアリール基であり、これら基は鎖中にカルボニル基を含んでいてもよい。あるいは、Ｒ_ｚ ^２０９はＲ_ｚ ^２０８と結合して環を形成していてもよい。Ｒ_ｚ ^２１０は２価の脂肪族、脂環式又は芳香族基であり、Ｒ_ｚ ^２１１は酸解離性基である。ｑは０又は１である。］

[In the formula, R _z ²⁰¹ to R _z ²⁰⁶ each independently represent a linear or branched alkyl group, a linear or branched alkoxy group, a linear or branched alkoxyalkyl group , a linear or branched alkenyl group, or an aryl group, and these groups may contain a carbonyl group in the chain. Alternatively, R _z ²⁰¹ and R _z ²⁰² and R _z ²⁰⁴ and R _z ²⁰⁵ may be bonded to each other to form a ring. R _z ²⁰⁷ and R _z ²⁰⁸ each independently represent a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, a linear or branched alkoxyalkyl group, It is a linear or branched alkenyl group or an aryl group. R _z ²⁰⁹ is a linear or branched alkyl group, a linear or branched alkoxyalkyl group, a linear or branched alkenyl group, or an aryl group, and these groups are may contain a carbonyl group. Alternatively, R _z ²⁰⁹ may be combined with R _z ²⁰⁸ to form a ring. R _z ²¹⁰ is a divalent aliphatic, alicyclic or aromatic group, and R _z ²¹¹ is an acid dissociable group. q is 0 or 1. ]

In the formulas (z2-r-1) to (z2-r-2), R _z ²⁰¹ to R _z ²⁰⁶ each independently represent a linear or branched alkyl group, a linear or branched an alkoxy group, a linear or branched alkoxyalkyl group, a linear or branched alkenyl group, or an aryl group, and these groups may contain a carbonyl group in the chain.
Examples of the alkyl group in R _z ²⁰¹ to R _z ²⁰⁶ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, hexyl group, cyclohexyl group, and adamantyl group. Those having 1 to 10 carbon atoms are preferred, and among them, methyl, ethyl, isopropyl, and tert-butyl groups are more preferred.
Examples of the alkoxy group in R _z ²⁰¹ to R _z ²⁰⁶ include methoxy group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, hexyloxy group, cyclohexyloxy group, etc. Those having 1 to 8 carbon atoms are preferred, and among them, methoxy, ethoxy, isopropoxy, and tert-butoxy groups are more preferred.
As the alkoxyalkyl group in R _z ²⁰¹ to R _z ²⁰⁶ , those having 2 to 10 carbon atoms such as methoxymethyl group, ethoxypropyl group, propoxyethyl group, tert-butoxyethyl group are preferable, and among them, methoxymethyl group , methoxyethyl group, ethoxypropyl group, propoxyethyl group, etc. are preferred.
The alkenyl group for R _z ²⁰¹ to R _z ²⁰⁶ is preferably one having 2 to 4 carbon atoms, such as a vinyl group, propenyl group, allyl group, or butenyl group.
The aryl group for R _z ²⁰¹ to R _z ²⁰⁶ is preferably one having 6 to 14 carbon atoms, such as a phenyl group, xylyl group, tolyl group, or cumenyl group.

In the formulas (z2-r-1) to (z2-r-2), R _z ²⁰¹ and R _z ²⁰² and R _z ²⁰⁴ and R _z ²⁰⁵ may be bonded to each other to form a ring.
Examples of the ring formed by bonding R _z ²⁰¹ and R _z ²⁰² to each other include a cyclohexylidene group, a cyclopentylidene group, a 3-oxocyclohexylidene group, a 4-methylcyclohexylidene group, etc. 4 to 10 are listed.
Examples of the ring formed by combining R _z ²⁰⁴ and R _z ²⁰⁵ include a 1-silacyclohexylidene group, a 1-silacyclopentylidene group, a 3-oxo-1-silacyclopentylidene group, and a 4-silacyclohexylidene group. Examples include those having 3 to 9 carbon atoms such as methyl-1-silacyclopentylidene group.

In the formula (z2-r-3), R _z ²⁰⁷ and R _z ²⁰⁸ each independently represent a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, a linear A linear or branched alkoxyalkyl group, a linear or branched alkenyl group, or an aryl group. R _z ²⁰⁹ is a linear or branched alkyl group, a linear or branched alkoxyalkyl group, a linear or branched alkenyl group, or an aryl group, and these groups are may contain a carbonyl group.
The alkyl group, alkoxy group, alkoxyalkyl group, alkenyl group, and aryl group in R _z ²⁰⁷ to R _z ²⁰⁹ are R _z ²⁰¹ to R _z in the above formulas (z2-r-1) to (z2-r-2). This is the same as the alkyl group, alkoxy group, alkoxyalkyl group, alkenyl group, and aryl group in ²⁰⁶ .

In the formula (z2-r-3), R _z ²⁰⁹ may be combined with R _z ²⁰⁸ to form a ring.
The ring formed by combining R _z ²⁰⁹ with R _z ²⁰⁸ includes, for example, a 2-oxacyclohexylidene group, a 2-oxacyclopentylidene group, a 2-oxa-4-methylcyclohexylidene group, etc. 4 to 10 are listed.

In the formula (z2-r-4), R _z ²¹⁰ is a divalent aliphatic, alicyclic or aromatic group.
The divalent aliphatic group in R _z ²¹⁰ includes those having 1 to 8 carbon atoms, such as methylene group, ethylene group, propylene group, butylene group, 2-methylpropylene group, and 2-methyl-3-ethoxybutylene group. Among them, methylene group, ethylene group, and propylene group are more preferably used.
Examples of the divalent alicyclic group in R _z ²¹⁰ include those having 5 to 10 carbon atoms such as a cyclohexylene group.
Examples of the divalent aromatic group in R _z ²¹⁰ include those having 6 to 14 carbon atoms, such as a phenylene group, a xylylene group, a tolylene group, and a cumenylene group.

In the above formula (z2-r-4), examples of the acid dissociable group for R _z ²¹¹ include groups represented by the above formulas (z2-r-1) to (z2-r-3).

In the formula (z2), R _z ³⁰ is a hydrogen atom or an organic group.
Examples of the organic group for R _z ³⁰ include a hydrocarbon group that may have a substituent.
Examples of the hydrocarbon group in R _z ³⁰ include a linear or branched alkyl group, or a cyclic hydrocarbon group.
The linear alkyl group in R _z ³⁰ preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, and n-pentyl group.
The branched alkyl group in R _z ³⁰ preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, and 2,2-dimethylbutyl group.

The cyclic hydrocarbon group in R _z ³⁰ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically Examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

The aromatic hydrocarbon group in R _z ³⁰ includes a group obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, and phenanthrene; a hydrogen atom from an aromatic heterocycle such as a pyridine ring and a thiophene ring. A group from which one hydrogen atom is removed from an aromatic compound containing two or more aromatic rings (e.g. biphenyl, fluorene, etc.); One hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle Examples include groups in which one group is substituted with an alkyl group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group), etc. . The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon number.

Examples of substituents that the hydrocarbon group in R _z ³⁰ may have include a linear, branched or cyclic alkyl group, an aromatic hydrocarbon group, a linear or branched alkoxy group, a hydroxy group, Examples include a carboxyl group, a halogen atom, and groups represented by the above formulas (z2-r-1) to (z2-r-4). The aromatic hydrocarbon group as a substituent which the hydrocarbon group in R _z ³⁰ may have further includes a linear, branched or cyclic alkyl group or the above formula (z2-r-1) as a substituent. It may have a group represented by ~(z2-r-4).

Component (Z2) is preferably at least one selected from the group consisting of groups represented by the following general formulas (z2-1) to (z2-2).

［式中、Ｖ_ｚ ^２は、２価の連結基である。Ｒ_ｚ ^２０、Ｒ_ｚ ^３３は、それぞれ独立に、酸解離性基である。Ｒ_ｚ ^３１、Ｒ_ｚ ^３２は、それぞれ独立に、水素原子又は有機基である。Ｒ_ｚ ^２５、Ｒ_ｚ ^２６は、それぞれ独立に、水素原子又は置換基を有してもよい炭化水素基である。ｎ１１は、１～５の整数である。ｎ１２は、０～４の整数である。ただし、ｎ１１＋ｎ１２＝５である。ｎ１３は、１～５の整数である。ｎ１４は、０～４の整数である。ただし、ｎ１３＋ｎ１４＝５である。］

[In the formula, V _z ² is a divalent linking group. R _z ²⁰ and R _z ³³ are each independently an acid dissociable group. R _z ³¹ and R _z ³² each independently represent a hydrogen atom or an organic group. R _z ²⁵ and R _z ²⁶ each independently represent a hydrogen atom or a hydrocarbon group which may have a substituent. n11 is an integer from 1 to 5. n12 is an integer from 0 to 4. However, n11+n12=5. n13 is an integer from 1 to 5. n14 is an integer from 0 to 4. However, n1 3 +n1 4 =5. ]

In the formula (z2-1), the divalent linking group in V _z ² is the same as the divalent linking group in Ya ^x1 in the formula (a10-1). Among these, the divalent linking group in V _z ² is preferably a linear alkylene group having 1 to 10 carbon atoms, such as a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ - ], trimethylene group [-(CH ₂ ) ₃ --], tetramethylene group [-(CH ₂ ) ₄ --], pentamethylene group [-(CH ₂ ) ₅ --] are more preferred, and methylene group is even more preferred.

In the formulas (z2-1) to (z2-2), the acid-dissociable groups in R _z ²⁰ and R _z ³³ are the same as the acid-dissociable group in R _z ²⁰ in the formula (z2). Among these, the acid-dissociable group in R _z ²⁰ and R _z ³³ is preferably a group represented by the formula (z2-r-4), and the group represented by the formula (z2-r-4) in R _z ²¹¹ is preferable. More preferably, the acid-dissociable group is a group represented by the above formula (z2-r-1).

In the formulas (z2-1) to (z2-2), the organic groups in R _z ³¹ and R _z ³² are the same as the organic group in R _z ³⁰ in the formula (z2). Among these, the organic group in R _z ³¹ and R _z ³² is preferably an aromatic hydrocarbon group which may have a substituent, and more preferably a group represented by the following general formula (z2-r-5). .

［式中、Ｒ_ｚ ^２０１は酸解離性基である。Ｒ_ｚ ^３０１は水素原子又はアルキル基である。ｎ１５は１～６の整数であり、ｎ１６は０～５の整数である。ただし、ｎ１５＋ｎ１６＝６である。ｎ１７は、０又は１である。＊は結合手を示す。］

[In the formula, R _z ²⁰¹ is an acid dissociable group. R _z ³⁰¹ is a hydrogen atom or an alkyl group. n15 is an integer from 1 to 6, and n16 is an integer from 0 to 5. However, n15+n16=6. n17 is 0 or 1. * indicates a bond. ]

In the formula (z2-r-5), the acid-dissociable group at R _z ²⁰¹ is the same as the acid-dissociable group at R _z ²⁰ in the formula (z2). Among these, the acid-dissociable group in R _z ²⁰¹ is preferably a group represented by the formula (z2-r-4), and the acid-dissociable group in R _z ²¹¹ in the formula (z2-r-4) is preferable. is more preferably a group represented by the above formula (z2-r-1).
In the formula (z2-r-5), the alkyl group for R _z ³⁰¹ is preferably a methyl group, an ethyl group, or a cyclohexyl group, and more preferably a methyl group or a cyclohexyl group.
In the formula (z2-r-5), n15 is preferably 1 or 2, and more preferably 1.
In the formula (z2-r-5), n16 is preferably 4 or 5, and more preferably 5.

In the formula (z2-2), the hydrocarbon groups in R _z ²⁵ and R _z ²⁶ are the same as the hydrocarbon group as the organic group in R _z ³⁰ in the formula (z2). Among these, R _z ²⁵ and R _z ²⁶ are preferably a hydrogen atom or an aromatic hydrocarbon group which may have a substituent, and a hydrogen atom or a group represented by the above formula (z2-r-5) is more preferable.

In the formulas (z2-1) to (z2-2), n11 and n13 are preferably 1 or 2, and more preferably 1.
In the formulas (z2-1) to (z2-2), n16 is preferably 4 or 5, and more preferably 5.

Specific examples of component (Z2) include compounds represented by the following chemical formulas (Z2-1) and (Z2-2), and compounds described in paragraphs [0046] to [0050] of JP-A No. 2005-122097. Examples include compounds that have been

Other specific examples of component (Z2) include the compounds described in paragraphs [0034], [0036], and [0037] of JP-A-9-278699, and the compounds described in paragraph [0119] of JP-A-10-097075. ]-[0122] and the like.

The component (Z2) contained in the resist composition may be used alone or in combination of two or more.

In the resist composition of the present embodiment, the content of component (Z) is preferably 30 parts by mass or less, more preferably 10 to 30 parts by mass, per 100 parts by mass of component (A).
When the ratio of the component (Z) is within the above-mentioned preferred range, it is easy to form a pattern with good etching resistance and a good shape.
Further, in the resist composition of the present embodiment, the blending ratio (mass ratio) of the (Z1) component and (Z2) component in the (Z) component is Z1:Z2 = 75:25 to 25:75. is preferable, Z1:Z2=70:30 to 40:60 is more preferable, and Z1:Z2=67:33 to 45:55 is still more preferable.
When the compounding ratio (mass ratio) of the (Z1) component and the (Z2) component in the (Z) component is within the above-mentioned preferred range, a pattern with good etching resistance and a good shape can be formed. It's easy to do.

<Optional ingredients>
≪Component (B): Acid generator component≫
The resist composition of the present embodiment preferably contains, in addition to the component (A) and the component (Z), an acid generator component (component (B)) that generates acid upon exposure.
Component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resist compositions can be used.
Such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts; oxime sulfonate acid generators; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl)diazomethanes; Acid generators include a wide variety of acid generators such as nitrobenzylsulfonate acid generators, iminosulfonate acid generators, and disulfone acid generators.

Examples of onium salt-based acid generators include compounds represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), and compounds represented by the general formula (b-2). Examples include a compound (hereinafter also referred to as "component (b-2)") or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

［式中、Ｒ^１０１、Ｒ^１０４～Ｒ^１０８はそれぞれ独立に、置換基を有してもよい環式基、置換基を有してもよい鎖状のアルキル基、又は置換基を有してもよい鎖状のアルケニル基である。Ｒ^１０４、Ｒ^１０５は、相互に結合して環を形成していてもよい。Ｒ^１０２はフッ素原子又は炭素数１～５のフッ素化アルキル基である。Ｙ^１０１は単結合、又は酸素原子を含む２価の連結基である。Ｖ^１０１～Ｖ^１０３はそれぞれ独立に単結合、アルキレン基又はフッ素化アルキレン基である。Ｌ^１０１～Ｌ^１０２はそれぞれ独立に単結合又は酸素原子である。Ｌ^１０３～Ｌ^１０５はそれぞれ独立に単結合、－ＣＯ－又は－ＳＯ_２－である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

[In the formula, R ¹⁰¹ , R ¹⁰⁴ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent It is a good chain alkenyl group. R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ¹⁰¹ to V ¹⁰³ are each independently a single bond, an alkylene group or a fluorinated alkylene group. L ¹⁰¹ to L ¹⁰² are each independently a single bond or an oxygen atom. L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -. m is an integer of 1 or more, and M' ^m+ is an m-valent onium cation. ]

{Anion part}
- Anion moiety of component (b-1) In formula (b-1), R ¹⁰¹ is a cyclic group that may have a substituent, a chain alkyl group that may have a substituent, or a substituted It is a chain alkenyl group which may have a group.

Cyclic group that may have a substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Aliphatic hydrocarbon group means a hydrocarbon group without aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

The aromatic hydrocarbon group in R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and 6 to 30 carbon atoms. 10 is most preferred. However, the number of carbon atoms does not include the number of carbon atoms in substituents.
Specifically, the aromatic ring possessed by the aromatic hydrocarbon group in R ¹⁰¹ is benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples include aromatic heterocycles. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group in R ¹⁰¹ is a group in which one hydrogen atom is removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), an alkylene group in which one of the hydrogen atoms in the aromatic ring is (eg, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group), and the like. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon number.

Examples of the cyclic aliphatic hydrocarbon group in R ¹⁰¹ include aliphatic hydrocarbon groups containing a ring in the structure.
The aliphatic hydrocarbon group containing a ring in its structure includes an alicyclic hydrocarbon group (a group in which one hydrogen atom is removed from an aliphatic hydrocarbon ring), an alicyclic hydrocarbon group that is linear or branched. Examples include a group bonded to the end of a chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 3 to 20 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkanes include polycycloalkanes having polycyclic skeletons such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; condensed ring systems such as cyclic groups having steroid skeletons; More preferred are polycycloalkanes having a polycyclic skeleton.

Among these, as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ , a group obtained by removing one or more hydrogen atoms from a monocycloalkane or polycycloalkane is preferable, and a group obtained by removing one hydrogen atom from a polycycloalkane is more preferable. Particularly preferred are an adamantyl group, a norbornyl group, and a cyclic group having a steroid skeleton, and most preferred are an adamantyl group and a cyclic group having a steroid skeleton.

The linear or branched aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and The number of carbon atoms is more preferably 1 to 4, and the number of carbon atoms is particularly preferably 1 to 3.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups; CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ - and other alkyltrimethylene groups; -CH(CH ₃ ) Examples include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ )CH ₂ CH ₂ -, and the like. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

Furthermore, the cyclic hydrocarbon group in R ¹⁰¹ may contain a heteroatom such as a heterocycle. Specifically, lactone-containing cyclic groups represented by the above general formulas (a2-r-1) to (a2-r-7), respectively, and the above general formulas (a5-r-1) to (a5-r- -SO ₂ --containing cyclic groups represented by 4), and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16), respectively.

Examples of the substituent in the cyclic group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. and ethoxy groups are most preferred.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, with a fluorine atom being preferred.
Examples of the halogenated alkyl group as a substituent include an alkyl group having 1 to 5 carbon atoms, such as a methyl group, ethyl group, propyl group, n-butyl group, and tert-butyl group, in which some or all of the hydrogen atoms are Examples include groups substituted with halogen atoms.
The carbonyl group as a substituent is a group that substitutes a methylene group (-CH ₂ -) constituting a cyclic hydrocarbon group.

Chain-like alkyl group which may have a substituent:
The chain alkyl group for R ¹⁰¹ may be either linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group. group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group, and the like.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

Chain alkenyl group which may have a substituent:
The chain alkenyl group of R ¹⁰¹ may be linear or branched, preferably has 2 to 10 carbon atoms, more preferably has 2 to 5 carbon atoms, and has 2 to 4 carbon atoms. More preferably, the number of carbon atoms is 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, and 2-methylpropenyl group.
As the chain alkenyl group, among the above, a straight chain alkenyl group is preferable, a vinyl group and a propenyl group are more preferable, and a vinyl group is particularly preferable.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the cyclic group in R ¹⁰¹ above. Can be mentioned.

Among these, R ¹⁰¹ is preferably a cyclic group that may have a substituent, and more preferably a cyclic hydrocarbon group that may have a substituent. More specifically, a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, a polycycloalkane; Lactone-containing cyclic groups represented by -7); -SO ₂ -containing cyclic groups represented by general formulas (a5-r-1) to (a5-r-4), etc. are preferred.

In the formula (b-1), Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain atoms other than the oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.
Examples of such divalent linking groups containing an oxygen atom include linking groups represented by the above general formulas (y-al-1) to (y-al-8), respectively.
Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, each represented by the above general formulas (y-al-1) to (y-al-5). More preferred are linking groups.

In the formula (b-1), V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group in V ¹⁰¹ preferably have 1 to 4 carbon atoms. The fluorinated alkylene group in V ¹⁰¹ includes a group in which some or all of the hydrogen atoms of the alkylene group in V ¹⁰¹ are substituted with fluorine atoms. Among these, V ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

In the formula (b-1), R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ¹⁰² is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

Specific examples of the anion moiety of component ⁽ b-1) include, for example, when Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; In the case of a divalent linking group containing an oxygen atom, examples include anions represented by any of the following formulas (an-1) to (an-3).

［式中、Ｒ”^１０１は、置換基を有してもよい脂肪族環式基、上記の化学式（ｒ－ｈｒ－１）～（ｒ－ｈｒ－６）でそれぞれ表される１価の複素環式基、又は置換基を有してもよい鎖状のアルキル基である。Ｒ”^１０２は、置換基を有してもよい脂肪族環式基、前記一般式（ａ２－ｒ－１）、（ａ２－ｒ－３）～（ａ２－ｒ－７）でそれぞれ表されるラクトン含有環式基、又は前記一般式（ａ５－ｒ－１）～（ａ５－ｒ－４）でそれぞれ表される－ＳＯ_２－含有環式基である。Ｒ”^１０３は、置換基を有してもよい芳香族環式基、置換基を有してもよい脂肪族環式基、又は置換基を有してもよい鎖状のアルケニル基である。Ｖ”^１０１は、単結合、炭素数１～４のアルキレン基、又は炭素数１～４のフッ素化アルキレン基である。Ｒ^１０２は、フッ素原子又は炭素数１～５のフッ素化アルキル基である。ｖ”はそれぞれ独立に０～３の整数であり、ｑ”はそれぞれ独立に１～２０の整数であり、ｎ”は０または１である。］

[In the formula, ^R''101 is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), respectively. It is a cyclic group or a chain alkyl group which may have a substituent.R" ¹⁰² is an aliphatic cyclic group which may have a substituent, the general formula (a2-r-1) , a lactone-containing cyclic group represented by (a2-r-3) to (a2-r-7), respectively, or a lactone-containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively. is a -SO ₂ -containing cyclic group. ^R''103 is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. V" ¹⁰¹ is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. v'' are each independently an integer from 0 to 3, q'' are each independently an integer from 1 to 20, and n'' is 0 or 1.]

The aliphatic cyclic group which may have a substituent for R" ¹⁰¹ , R" ¹⁰² and R" ¹⁰³ is preferably a group exemplified as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ above. Examples of the group include the same substituents that may substitute the cyclic aliphatic hydrocarbon group in ^R101 .

The aromatic cyclic group which may have a substituent in R" ¹⁰³ is preferably the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R ^101. The substituent is: The same substituents as those that may substitute the aromatic hydrocarbon group in R ¹⁰¹ can be mentioned.

The chain alkyl group which may have a substituent in ^R''101 is preferably the group exemplified as the chain alkyl group in ^R101 above.Even if it has a substituent in ^R''104 , A good chain alkenyl group is preferably a group exemplified as the chain alkenyl group in R ¹⁰¹ above.

V" ¹⁰¹ is preferably a single bond or a fluorinated alkylene group, more preferably a single bond or a fluorinated alkylene group having 1 to 3 carbon atoms. When V" ¹⁰¹ is a fluorinated alkylene group -V" ¹⁰¹ -C(F)(R" ¹⁰² ) _-SO3 ^- V" ¹⁰¹ is -CF2-, _-CHF- , _{-CF2CF2- , -CHFCF2-} , -CF( _CF3 ) _CF2 -, -CH(CF ₃ )CF ₂ - are preferred, and -CF ₂ - and -CHF- are more preferred.

R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ¹⁰² is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

v" is an integer of 0 to 3, preferably 0 or 1. q" is an integer of 1 to 20, preferably an integer of 1 to 10, more preferably an integer of 1 to 5. , more preferably 1, 2 or 3, particularly preferably 1 or 2. n'' is 0 or 1.

・(b-2) Anion moiety of component In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ each independently represent a cyclic group that may have a substituent, a chain that may have a substituent A chain-like alkyl group or a chain-like alkenyl group which may have a substituent, and examples thereof include the same groups as R ¹⁰¹ in the above formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably a chain alkyl group that may have a substituent, and are a linear or branched alkyl group or a linear or branched fluorinated alkyl group. is more preferable.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. The smaller the number of carbon atoms in the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is, within the above range, the better, for reasons such as good solubility in a resist solvent. Furthermore, in the chain alkyl groups of R ¹⁰⁴ and R ¹⁰⁵ , the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, which is preferable. The proportion of fluorine atoms in the chain alkyl group, that is, the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. It is a perfluoroalkyl group.
In formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each of them is the same as V ¹⁰¹ in formula (b-1). Can be mentioned.
In formula (b-2), L ¹⁰¹ and L ¹⁰² are each independently a single bond or an oxygen atom.

- Anion moiety of component (b-3) In formula (b-3), R ¹⁰⁶ to R ¹⁰⁸ each independently represent a cyclic group that may have a substituent, or a chain that may have a substituent. A chain-like alkyl group or a chain-like alkenyl group which may have a substituent, and examples thereof include the same groups as R ¹⁰¹ in formula (b-1).
L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -.

{Cation part}
In formulas (b-1), (b-2) and (b-3), m is an integer of 1 or more, and M' ^m+ is an m-valent onium cation, preferably a sulfonium cation or an iodonium cation. For example, organic cations represented by the above general formulas (ca-1) to (ca-4) can be mentioned.

［式中、Ｒ^２０１～Ｒ^２０７及びＲ^２１１～Ｒ^２１２はそれぞれ独立に、置換基を有してもよいアリール基、置換基を有してもよいアルキル基、又は置換基を有してもよいアルケニル基を表す。Ｒ^２０１～Ｒ^２０３、Ｒ^２０６～Ｒ^２０７、Ｒ^２１１～Ｒ^２１２はそれぞれ、相互に結合して式中のイオウ原子と共に環を形成していてもよい。Ｒ^２０８～Ｒ^２０９は、それぞれ独立に、水素原子もしくは炭素数１～５のアルキル基を表すか、又は相互に結合して式中のイオウ原子と共に環を形成していてもよい。Ｒ^２１０は、置換基を有してもよいアリール基、置換基を有してもよいアルキル基、置換基を有してもよいアルケニル基、又は置換基を有してもよい－ＳＯ_２－含有環式基である。Ｌ^２０１は、－Ｃ（＝Ｏ）－又は－Ｃ（＝Ｏ）－Ｏ－を表す。複数のＹ^２０１はそれぞれ独立に、アリーレン基、アルキレン基又はアルケニレン基を表す。ｘは、１又は２である。Ｗ^２０１は、（ｘ＋１）価の連結基を表す。］

[In the formula, R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² are each independently an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkyl group which may have a substituent. Represents a good alkenyl group. R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ , and R ²¹¹ to R ²¹² may each be bonded to each other to form a ring with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, or may be bonded to each other to form a ring with the sulfur atom in the formula. R ²¹⁰ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or -SO ₂ - which may have a substituent. It is a containing cyclic group. L ²⁰¹ represents -C(=O)- or -C(=O)-O-. Each of the plurality of ^Y201 's independently represents an arylene group, an alkylene group, or an alkenylene group. x is 1 or 2. W ²⁰¹ represents a (x+1)-valent linking group. ]

Examples of the aryl group for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² include aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred.
The alkyl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² preferably has 2 to 10 carbon atoms.
Examples of substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and the following general groups. Examples include groups represented by formulas (car-r-1) to (car-r-7), respectively.

［式中、Ｒ’^２０１は、それぞれ独立に、水素原子、置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、又は置換基を有していてもよい鎖状のアルケニル基である。］

[In the formula, R' ²⁰¹ is each independently a hydrogen atom, a cyclic group that may have a substituent, a chain alkyl group that may have a substituent, or a It is a chain alkenyl group which may be ]

The cyclic group that may have a substituent, the chain alkyl group that may have a substituent, or the chain alkenyl group that may have a substituent for ^R'201 are as described below. In addition to those similar to R ¹⁰¹ in formula (b-1), examples of the cyclic group that may have a substituent or the chain alkyl group that may have a substituent include those mentioned above. Also included are those similar to the acid dissociable group represented by formula (a1-r-2).

When R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ , and R ²¹¹ to R ²¹² are bonded to each other to form a ring together with the sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom, a nitrogen atom, Carbonyl group, -SO-, -SO ₂ -, -SO ₃ -, -COO-, -CONH- or -N(R _N )- (R _N is an alkyl group having 1 to 5 carbon atoms), etc. may be bonded via a functional group. As for the ring to be formed, one ring in the formula containing a sulfur atom in its ring skeleton is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring. preferable. Specific examples of the ring formed include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, and a tetrahydrocarbon ring. Examples include a thiophenium ring and a tetrahydrothiopyranium ring.

R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when they are an alkyl group, they are bonded to each other. It may form a ring.

R ²¹⁰ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. -SO ₂ -containing cyclic group.
Examples of the aryl group for R ²¹⁰ include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred.
The alkyl group for R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms. The -SO ₂ --containing cyclic group which may have a substituent in R ²¹⁰ is preferably a "-SO ₂ --containing polycyclic group", and is represented by the general formula (a5-r-1) above. More preferred are groups such as

Y ²⁰¹ each independently represents an arylene group, an alkylene group, or an alkenylene group.
Examples of the arylene group in Y ²⁰¹ include a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group in R ¹⁰¹ in formula (b-1) described below.
Examples of the alkylene group and alkenylene group in Y ²⁰¹ include groups obtained by removing one hydrogen atom from the groups exemplified as the chain alkyl group and chain alkenyl group in R ¹⁰¹ in formula (b-1) described below. .

In the formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x+1)-valent, ie, divalent or trivalent, linking group.
The divalent linking group in W ²⁰¹ is preferably a divalent hydrocarbon group which may have a substituent, and a divalent hydrocarbon group having a substituent similar to Ya ²¹ in the above general formula (a2-1) is preferable. An example is a divalent hydrocarbon group which may be The divalent linking group in W ²⁰¹ may be linear, branched, or cyclic, and is preferably cyclic. Among these, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, with a phenylene group being particularly preferred.
Examples of the trivalent linking group in W ²⁰¹ include a group obtained by removing one hydrogen atom from the divalent linking group in W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, etc. Can be mentioned. The trivalent linking group in W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

Specifically, suitable cations represented by the above formula (ca-1) include the following chemical formulas (ca-1-1) to (ca-1-78), (ca-1-101) to (ca- 1-149), respectively.
In the chemical formula below, g1 represents the number of repeats, and g1 is an integer from 1 to 5. g2 indicates the number of repetitions, and g2 is an integer from 0 to 20. g3 indicates the number of repetitions, and g3 is an integer from 0 to 20.

［式中、Ｒ”^２０１は水素原子又は置換基である。該置換基としては、上記Ｒ^２０１～Ｒ^２０７およびＲ^２１１～Ｒ^２１２が有してもよい置換基として挙げた、アルキル基、ハロゲン原子、ハロゲン化アルキル基、カルボニル基、シアノ基、アミノ基、アリール基、一般式（ｃａ－ｒ－１）～（ｃａ－ｒ－７）でそれぞれ表される基が挙げられる。］

[In the formula, R'' ²⁰¹ is a hydrogen atom or a substituent. Examples of the substituent include an alkyl group, a halogen group, and the like as the substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² may have. Examples include atoms, halogenated alkyl groups, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by general formulas (car-r-1) to (car-r-7), respectively.]

Specifically, preferred cations represented by the formula (ca-2) include cations represented by the following formulas (ca-2-1) to (ca-2-3), diphenyliodonium cations, bis( Examples include 4-tert-butylphenyl)iodonium cation.

Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-7).

Specific examples of suitable cations represented by the above formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

Among the above, the cation moiety ((M ^m+ ) _1/m ) is preferably a cation represented by the general formula (ca-1) or (ca-2), and the cation moiety ((M m+ ) 1/m ) is preferably a cation represented by the general formula (ca-1) or (ca-2). 1-78), (ca-1-101) to (ca-1-149) and chemical formulas (ca-2-1) to (ca-2-3), respectively, are more preferred.

Examples of the iminosulfonate acid generator include a compound represented by the following general formula (b-4) (hereinafter also referred to as "component (b-4)").

［式中、Ｒ^２１３は、置換を有してもよいアルキル基、又は置換基を有してもよいアリール基である。Ａは、置換を有してもよいアルキレン基、置換を有してもよいアルケニレン基、又は置換を有してもよいアリーレン基である。］

[In the formula, R ²¹³ is an optionally substituted alkyl group or an optionally substituted aryl group. A is an optionally substituted alkylene group, an optionally substituted alkenylene group, or an optionally substituted arylene group. ]

Specific examples of component (b-4) include compounds represented by the following chemical formula (B1-1) and compounds described in paragraphs [0089] to [0091] of JP-A-10-097075. It will be done.

In the resist composition of the present embodiment, the component (B) may be used alone or in combination of two or more.
When the resist composition contains component (B), the content of component (B) in the resist composition is preferably 50 parts by mass or less, and 0.1 to 40 parts by mass, based on 100 parts by mass of component (A). Parts by weight are more preferable, even more preferably 0.1 to 30 parts by weight, particularly preferably 0.1 to 20 parts by weight.
By setting the content of component (B) within the above range, pattern formation can be sufficiently performed.

≪(D) Component≫
The resist composition in this embodiment may further contain an acid diffusion control agent component (hereinafter referred to as "component (D)") in addition to component (A) and component (Z). Component (D) acts as a quencher (acid diffusion control agent) that traps acid generated by exposure in the resist composition.
Component (D) includes, for example, a nitrogen-containing organic compound (D1) (hereinafter referred to as "component (D1)"), a photodegradable base (D2) that decomposes upon exposure and loses acid diffusion controllability, which does not fall under the component (D1). ) (hereinafter referred to as "component (D2)").
By using a resist composition containing component (D), it is possible to further improve the contrast between exposed and unexposed areas of the resist film when forming a resist pattern.

- Regarding component (D1) Component (D1) is a base component, and is a nitrogen-containing organic compound component that acts as an acid diffusion control agent in the resist composition.

Component (D1) is not particularly limited as long as it acts as an acid diffusion control agent, and examples thereof include aliphatic amines, aromatic amines, and the like.

Among the aliphatic amines, secondary aliphatic amines and tertiary aliphatic amines are preferred.
The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.
Examples of aliphatic amines include amines (alkyl amines or alkyl alcohol amines) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkyl amines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, tri- Examples include alkyl alcohol amines such as isopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specifically, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5. 4.0]-7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane, and the like.

Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2- (1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy) ) ethoxy}ethyl]amine, triethanolamine triacetate, etc., with triethanolamine triacetate being preferred.

Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, aniline compounds, N-tert-butoxycarbonylpyrrolidine, and the like.

Component (D1) may be used alone or in combination of two or more.
Among the above components, component (D1) is preferably an aromatic amine, and more preferably an aniline compound. Examples of the aniline compound include 2,6-diisopropylaniline, N,N-dimethylaniline, N,N-dibutylaniline, and N,N-dihexylaniline.

・About component (D2) Component (D2) is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion control properties, and can be a compound represented by the following general formula (d2-1) (hereinafter referred to as "( d2-1) component"), a compound represented by the following general formula (d2-2) (hereinafter referred to as "(d2-2) component"), and a compound represented by the following general formula (d2-3) (hereinafter referred to as "component (d2-3)") is preferably one or more compounds selected from the group consisting of:
Components (d2-1) to (d2-3) decompose in the exposed areas of the resist film and lose their acid diffusion control properties (basicity), so they do not act as quenchers, and they act as quenchers in the unexposed areas of the resist film. It acts as.

［式中、Ｒｄ^１～Ｒｄ^４は置換基を有してもよい環式基、置換基を有してもよい鎖状のアルキル基、又は置換基を有してもよい鎖状のアルケニル基である。但し、一般式（ｄ２－２）中のＲｄ^２における、Ｓ原子に隣接する炭素原子にはフッ素原子が結合していないものとする。Ｙｄ^１は単結合又は２価の連結基である。ｍは１以上の整数であって、Ｍ’^ｍ＋はそれぞれ独立にｍ価のオニウムカチオンである。］

[In the formula, Rd ¹ to Rd ⁴ are a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. It is. However, it is assumed that no fluorine atom is bonded to the carbon atom adjacent to the S atom in Rd ² in the general formula (d2-2). Yd ¹ is a single bond or a divalent linking group. m is an integer of 1 or more, and M' ^m+ each independently represents an m-valent onium cation. ]

{(d2-1) component}
・Anion part In formula (d2-1), Rd ¹ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group, and examples thereof include those similar to R ¹⁰¹ in the above formula (b-1).
Among these, Rd ¹ is an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain type which may have a substituent. Alkyl groups are preferred. Substituents that these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, and the above general formulas (a2-r-1) to (a2-r-7). ), lactone-containing cyclic groups, ether bonds, ester bonds, or combinations thereof. When an ether bond or an ester bond is included as a substituent, it may be via an alkylene group, and the substituent in this case is represented by the above formulas (y-al-1) to (y-al-5), respectively. A linking group is preferred.
Preferred examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (for example, a polycyclic structure consisting of a ring structure of a bicyclooctane skeleton and other ring structures). It will be done.
The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, Straight chain alkyl groups such as nonyl group and decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group Examples include branched alkyl groups such as 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and 1 -4 is more preferred. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, and nitrogen atoms.
Rd ¹ is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms; A fluorinated alkyl group (linear perfluoroalkyl group) in which all fluorine atoms are substituted is particularly preferred.

Preferred specific examples of the anion moiety of component (d2-1) are shown below.

-Cation part In formula (d2-1), M' ^m+ is an m-valent onium cation.
As the onium cation of M' ^m+ , the same cations as the cations represented by the above general formulas (ca-1) to (ca-4) are preferably mentioned, and the onium cations represented by the above general formula (ca-1) are preferably mentioned. More preferred are cations represented by the above formulas (ca-1-1) to (ca-1-78) and (ca-1-101) to (ca-1-149), respectively.
Component (d2-1) may be used alone or in combination of two or more.

{(d2-2) component}
・Anion part In formula (d2-2), Rd ² is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group, and examples include those similar to R ¹⁰¹ in the above formula (b-1).
However, it is assumed that no fluorine atom is bonded to the carbon atom adjacent to the S atom in Rd ² (not substituted with fluorine). As a result, the anion of the component (d2-2) becomes an appropriately weak acid anion, and the quenching ability of the component (D2) is improved.
Rd ² is preferably a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. Examples of aliphatic cyclic groups include groups obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent); one or more from camphor, etc. More preferably, it is a group from which a hydrogen atom is removed.
^The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain The same substituents as the alkyl group) may be included.

Preferred specific examples of the anion moiety of component (d2-2) are shown below.

-Cation moiety In formula (d2-2), M' ^m+ is an m-valent onium cation, and is the same as M' ^m+ in formula (d2-1) above.
Component (d2-2) may be used alone or in combination of two or more.

{(d2-3) component}
・Anion part In formula (d2-3), Rd ³ is a cyclic group that may have a substituent, a chain alkyl group that may have a substituent, or a chain that may have a substituent. It is a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group, such as the same as R ¹⁰¹ in the above formula (b-1). is preferred. Among these, a fluorinated alkyl group is preferred, and the same fluorinated alkyl group as Rd ¹ above is more preferred.

In formula (d2-3), Rd ⁴ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkyl group which may have a substituent. It is an alkenyl group, and examples include those similar to R ¹⁰¹ in the above formula (b-1).
Among these, preferred are alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups that may have substituents.
The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group. , tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A portion of the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group in Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n- Examples include butoxy group and tert-butoxy group. Among them, methoxy group and ethoxy group are preferred.

Examples of the alkenyl group in Rd ⁴ include those similar to R ¹⁰¹ in the above formula (b-1), and vinyl group, propenyl group (allyl group), 1-methylpropenyl group, and 2-methylpropenyl group are preferable. . These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

Examples of the cyclic group in Rd ⁴ include those similar to R ¹⁰¹ in the above formula (b-1), and include cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group obtained by removing one or more hydrogen atoms from , or an aromatic group such as a phenyl group or a naphthyl group is preferable. When Rd ⁴ is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in good lithography properties.

In formula (d2-3), Yd ¹ is a single bond or a divalent linking group.
The divalent linking group in Yd ¹ is not particularly limited, but includes divalent hydrocarbon groups that may have substituents (aliphatic hydrocarbon groups, aromatic hydrocarbon groups), divalent hydrocarbon groups containing heteroatoms, etc. Examples include linking groups such as These are the divalent hydrocarbon group which may have a substituent, the divalent linking group in Ya ^x1 in the above formula (a10-1), and the heteroatom-containing divalent Examples include those similar to the valent linking group.
Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

Preferred specific examples of the anion moiety of component (d2-3) are shown below.

-Cation moiety In formula (d2-3), M' ^m+ is an m-valent onium cation, and is the same as M' ^m+ in formula (d2-1) above.
Component (d2-3) may be used alone or in combination of two or more.

As the component (D2), any one of the components (d2-1) to (d2-3) above may be used alone, or two or more thereof may be used in combination.
When the resist composition contains component (D2), the content of component (D2) in the resist composition is preferably 0.5 to 35 parts by mass, and 1 to 35 parts by mass, based on 100 parts by mass of component (A). It is more preferably 25 parts by weight, even more preferably 2 to 20 parts by weight, and particularly preferably 3 to 15 parts by weight.
When the content of the component (D2) is at least the preferable lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained. On the other hand, when the content is below the upper limit, a balance with other components can be maintained, and various lithography properties become favorable.

(D2) Method for producing component:
The method for producing the components (d2-1) and (d2-2) is not particularly limited, and they can be produced by known methods.
Further, the method for producing component (d2-3) is not particularly limited, and is produced, for example, in the same manner as the method described in US2012-0149916.

≪Component (E): at least one compound selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and derivatives thereof≫
The resist composition of this embodiment contains an organic carboxylic acid, a phosphorus oxoacid, and its derivatives as optional components for the purpose of preventing sensitivity deterioration, improving resist pattern shape, storage stability over time, etc. At least one compound (E) selected from the group (hereinafter referred to as "component (E)") can be contained.
Suitable organic carboxylic acids include, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid.
Examples of the phosphorus oxoacid include phosphoric acid, phosphonic acid, and phosphinic acid, and among these, phosphonic acid is particularly preferred.
Examples of derivatives of phosphorus oxo acids include esters in which the hydrogen atoms of the above oxo acids are replaced with hydrocarbon groups, and the hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms, and esters having 6 to 5 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphoric acid ester and diphenyl phosphoric acid ester.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of derivatives of phosphinic acid include phosphinic esters and phenylphosphinic acid.
In the resist composition of the present embodiment, one kind of component (E) may be used alone, or two or more kinds may be used in combination.
When the resist composition contains component (E), the content of component (E) is usually used in the range of 0.01 to 5 parts by mass based on 100 parts by mass of component (A).

≪Component (F): Fluorine additive component≫
The resist composition of the present embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") in order to impart water repellency to the resist film or improve lithography properties.
The component (F) is described, for example, in JP-A No. 2010-002870, JP-A No. 2010-032994, JP-A No. 2010-277043, JP-A No. 2011-13569, and JP-A No. 2011-128226. The following fluorine-containing polymer compounds can be used.
More specifically, component (F) includes a polymer having a structural unit (f1) represented by the following formula (f1-1). This polymer includes a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the above structural unit (a1); Preferably, it is a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, 1-methyl-1-adamantyl ( Preference is given to building blocks derived from meth)acrylates.

［式中、Ｒは前記と同様であり、Ｒｆ^１０２およびＲｆ^１０３はそれぞれ独立して水素原子、ハロゲン原子、炭素数１～５のアルキル基又は炭素数１～５のハロゲン化アルキル基を表し、Ｒｆ^１０２およびＲｆ^１０３は同じであっても異なっていてもよい。ｎｆ^１は１～５の整数であり、Ｒｆ^１０１はフッ素原子を含む有機基である。］

[wherein R is the same as above, Rf ¹⁰² and Rf ¹⁰³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, Rf ¹⁰² and Rf ¹⁰³ may be the same or different. nf ¹ is an integer from 1 to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom. ]

In formula (f1-1), R bonded to the carbon atom at the α position is the same as described above. As R, a hydrogen atom or a methyl group is preferable.
In formula (f1-1), examples of the halogen atom for Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, with a fluorine atom being particularly preferred. Examples of the alkyl group having 1 to 5 carbon atoms for Rf ¹⁰² and Rf ¹⁰³ include those similar to the alkyl group having 1 to 5 carbon atoms for R above, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms in Rf ¹⁰² and Rf ¹⁰³ include groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. It will be done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, with a fluorine atom being particularly preferred. Among these, Rf ¹⁰² and Rf ¹⁰³ are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group.
In formula (f1-1), nf ¹ is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms. , carbon atoms of 1 to 10 are particularly preferred.
Further, in the hydrocarbon group containing a fluorine atom, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and 60% or more are fluorinated. It is particularly preferable that the resist be fluorinated because it increases the hydrophobicity of the resist film during immersion exposure.
Among them, Rf ¹⁰¹ is preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, such as trifluoromethyl group, -CH ₂ -CF ₃ , -CH ₂ -CF ₂ -CF ₃ , -CH(CF ₃ ) ₂ , -CH ₂ -CH ₂ -CF ₃ and -CH ₂ -CH ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₃ are particularly preferred.

The mass average molecular weight (Mw) of the component (F) (based on polystyrene standards determined by gel permeation chromatography) is preferably from 1,000 to 50,000, more preferably from 5,000 to 40,000, and most preferably from 10,000 to 30,000. When it is below the upper limit of this range, there is sufficient solubility in a resist solvent for use as a resist, and when it is above the lower limit of this range, the water repellency of the resist film is good.
The degree of dispersion (Mw/Mn) of component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

In the resist composition of the present embodiment, one kind of component (F) may be used alone, or two or more kinds may be used in combination.
When the resist composition contains component (F), the content of component (F) is usually 0.5 to 10 parts by mass based on 100 parts by mass of component (A).

≪(S) component: organic solvent component≫
The resist composition of this embodiment can be manufactured by dissolving a resist material in an organic solvent component (hereinafter referred to as "component (S)").
The component (S) may be any one as long as it can dissolve each component to be used and form a uniform solution, and any one can be used as appropriate from among those conventionally known as solvents for chemically amplified resist compositions. It can be used selectively.
As the component (S), for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol , polyhydric alcohols such as dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, the polyhydric alcohols or having the ester bond. Derivatives of polyhydric alcohols such as monoalkyl ethers of compounds such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or compounds having ether bonds such as monophenyl ether [Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate , methyl methoxypropionate, ethyl ethoxypropionate and other esters; anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenethol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, Examples include aromatic organic solvents such as xylene, cymene, and mesitylene, dimethyl sulfoxide (DMSO), and the like.
In the resist composition of this embodiment, the (S) component may be used alone or as a mixed solvent of two or more.
Among these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.
Further, a mixed solvent in which PGMEA and a polar solvent are mixed is also preferable. The blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and the polar solvent, but is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. It is preferable to keep it within this range.
More specifically, when blending EL or cyclohexanone as a polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. . Further, when PGME is blended as a polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7: It is 3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred.
In addition, as component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5.
The amount of component (S) to be used is not particularly limited, and is appropriately set at a concentration that allows coating on a substrate, etc., depending on the thickness of the coating film. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 50% by weight, preferably 10 to 50% by weight.

The resist composition of the present embodiment may further include miscible additives, such as additional resins, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents to improve the performance of the resist film, if desired. , dyes, etc. may be added and contained as appropriate.

In the resist composition of the present embodiment, impurities and the like may be removed using a polyimide porous membrane, a polyamide-imide porous membrane, etc. after dissolving the resist material in the (S) component. For example, the resist composition may be filtered using a filter made of a porous polyimide membrane, a filter made of a porous polyamide-imide membrane, a filter made of a porous polyimide membrane and a porous polyamide-imide membrane, or the like. Examples of the polyimide porous membrane and the polyamideimide porous membrane include those described in JP-A No. 2016-155121.

The resist composition of this embodiment contains a base component (A) and a dissolution inhibitor (Z). The dissolution inhibitor (Z) contains a compound (Z1) and a compound (Z2).
Generally, in a resist film formed using a resist composition, spaces are created between molecules constituting the base material component. As the molecular weight of the base component increases, the molecules constituting the base component also increase in size, and the spaces created between the molecules also increase. Such spaces generated in the resist film may reduce the adhesion of the resist film to the substrate.
In the resist composition of the present embodiment, compound (Z1) and compound (Z2) both have a mass average molecular weight of 3000 or less, and thus have a relatively small molecular size. Therefore, in the resist film formed using the resist composition of this embodiment, the compound (Z1) and the compound (Z2) are likely to be appropriately dispersed in the spaces created between the molecules constituting the base component (A). .
Since the compound (Z1) has a phenolic hydroxyl group or a carboxyl group in its molecule, it tends to segregate to the lower layer in the resist film. Therefore, it is presumed that the compound (Z1) contributes to improving the adhesion between the resist film and the substrate interface, and improves the etching resistance (particularly the wet etching resistance).
On the other hand, since compound (Z1) has a phenolic hydroxyl group or a carboxyl group in its molecule, it may cause film thinning of the resist film, especially in an alkaline development process. However, compound (Z2) is more hydrophobic than compound (Z1). Therefore, it is presumed that the compound (Z2) contributes to suppressing the thinning of the resist film that may occur due to the compound (Z1).
It is presumed that due to the synergistic effect of the compound (Z1) and the compound (Z2) as described above, a resist pattern with good etching resistance and a good shape can be obtained.

(Resist pattern formation method)
A second aspect of the present invention includes a step (i) of forming a resist film on a support using the resist composition according to the first aspect described above, a step (ii) of exposing the resist film, and The resist pattern forming method includes a step (iii) of developing the exposed resist film to form a resist pattern.
One embodiment of such a resist pattern forming method includes, for example, a resist pattern forming method performed as follows.

Step (i):
First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed for 40 to 200 seconds at a temperature of, for example, 80 to 160°C. Preferably, it is applied for 60 to 150 seconds to form a resist film.

Step (ii):
Next, the resist film is selectively exposed to light through a mask (mask pattern) on which a predetermined pattern is formed using an exposure device such as a KrF exposure device, and then baked (post-baked). Exposure bake (PEB) treatment is performed, for example, at a temperature of 80 to 150°C for 40 to 150 seconds, preferably 60 to 120 seconds.

Process (iii):
Next, the resist film is developed. The development process is performed using an alkaline developer in the case of an alkaline development process, and is performed using a developer containing an organic solvent (organic developer) in the case of a solvent development process.
After the development process, preferably a rinsing process is performed. For the rinsing treatment, in the case of an alkaline development process, water rinsing using pure water is preferable, and in the case of a solvent development process, it is preferable to use a rinsing liquid containing an organic solvent.
In the case of a solvent development process, after the development treatment or rinsing treatment, a process may be performed in which the developer or rinse agent adhering to the pattern is removed using a supercritical fluid.

After development processing or rinsing processing, drying is performed. In some cases, a bake process (post-bake) may be performed after the development process. The baking treatment (post-baking) is performed at a temperature of, for example, 80° C. or higher, preferably 90 to 120° C., for 10 to 120 seconds, preferably 300 to 90 seconds.
In this way, a resist pattern can be formed.

The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and substrates on which predetermined wiring patterns are formed. More specifically, examples include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. As the material for the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used.
Further, the support may be one in which an inorganic and/or organic film is provided on the above-mentioned substrate. Examples of the inorganic film include an inorganic antireflection film (inorganic BARC). Examples of the organic film include organic films such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method means that at least one layer of organic film (lower layer organic film) and at least one layer of resist film (upper layer resist film) are provided on a substrate, and the resist pattern formed on the upper layer resist film is used as a mask. This is a method of patterning a lower organic film, and is said to be able to form patterns with high aspect ratios. That is, according to the multilayer resist method, since the required thickness can be ensured by the lower organic film, the resist film can be made thinner, and a fine pattern with a high aspect ratio can be formed.
The multilayer resist method basically has a two-layer structure consisting of an upper resist film and a lower organic film (two-layer resist method), and a method in which one or more intermediate layers are formed between the upper resist film and the lower organic film. There are two methods: a method of creating a multilayer structure of three or more layers (three-layer resist method), and a method of forming a multilayer structure of three or more layers (metal thin film, etc.).

The resist pattern forming method of the embodiment is a method useful when forming a thick resist film. Even if the thickness of the resist film formed in step (i) is, for example, 1 to 10 μm, a resist pattern can be stably formed in a good shape.

The wavelength used for exposure is not particularly limited, and includes ultraviolet rays such as g-line and i-line, ArF excimer laser light, KrF excimer laser light, _F2 excimer laser light, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB ( This can be carried out using radiation such as electron beams), X-rays, and soft X-rays.
The resist composition according to the first embodiment described above is highly useful for ultraviolet rays such as g-line and i-line, KrF excimer laser beam, ArF excimer laser beam, EB or EUV, and is highly useful for ultraviolet rays such as g-line and i-line, It is more useful for ultraviolet rays, KrF excimer laser light, and ArF excimer laser light, and particularly useful for ultraviolet rays such as g-line and i-line, and KrF excimer laser light. The resist pattern forming method according to the second aspect is particularly suitable for irradiating the resist film with ultraviolet rays such as g-line and i-line, or KrF excimer laser light in step (ii).

The method of exposing the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion lithography.
In immersion exposure, the space between the resist film and the lowest lens of the exposure device is filled in advance with a solvent (immersion medium) that has a refractive index greater than that of air, and exposure (immersion exposure) is performed in that state. This is an exposure method.
The immersion medium is preferably a solvent having a refractive index greater than that of air and smaller than the refractive index of the resist film to be exposed. The refractive index of such a solvent is not particularly limited as long as it falls within the above range.
Examples of the solvent having a refractive index higher than that of air and lower than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, a hydrocarbon-based solvent, and the like.
Specific examples of fluorine-based inert liquids include those whose main component is a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ Examples include liquids, and those with a boiling point of 70 to 180°C are preferable, and those with a boiling point of 80 to 160°C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point within the above range because the medium used for immersion can be removed by a simple method after exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include perfluoroalkyl ether compounds and perfluoroalkylamine compounds.
Further, specifically, the perfluoroalkyl ether compound may include perfluoro(2-butyl-tetrahydrofuran) (boiling point 102°C), and the perfluoroalkylamine compound may include perfluorotributylamine ( (boiling point 174°C).
Water is preferably used as the immersion medium from the viewpoints of cost, safety, environmental issues, versatility, and the like.

Examples of the alkaline developer used in the alkaline development process include a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for development in the solvent development process may be any organic solvent as long as it can dissolve component (A) (component (A) before exposure), and may be selected from known organic solvents. You can choose as appropriate. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, hydrocarbon solvents, and the like.
A ketone solvent is an organic solvent containing CC(=O)-C in its structure. Ester solvents are organic solvents containing CC(=O)-OC in their structure. An alcoholic solvent is an organic solvent containing an alcoholic hydroxyl group in its structure. "Alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. A nitrile solvent is an organic solvent containing a nitrile group in its structure. An amide solvent is an organic solvent containing an amide group in its structure. Ether solvents are organic solvents containing C—O—C in their structure.
Among organic solvents, there are organic solvents that contain multiple types of functional groups that characterize each of the above solvents in their structure, but in that case, any solvent type that contains the functional groups that the organic solvent has shall be taken as a thing. For example, diethylene glycol monomethyl ether falls under both alcohol solvents and ether solvents in the above classification.
The hydrocarbon solvent is a hydrocarbon solvent that is made of a hydrocarbon that may be halogenated and has no substituent other than a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, with a fluorine atom being preferred.
As the organic solvent contained in the organic developer, polar solvents are preferred among the above, and ketone solvents, ester solvents, nitrile solvents, and the like are preferred.

Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, and methyl ethyl ketone. , methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), and the like. Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxy acetate, ethyl ethoxy acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate , 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether Acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3 -Methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, formic acid Propyl, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, propionic acid Ethyl, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate , propyl-3-methoxypropionate and the like. Among these, butyl acetate is preferred as the ester solvent.

Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, butyronitrile, and the like.

Known additives can be added to the organic developer, if necessary. Examples of such additives include surfactants. Although the surfactant is not particularly limited, for example, ionic or nonionic fluorine-based and/or silicon-based surfactants can be used. As the surfactant, a nonionic surfactant is preferred, and a nonionic fluorine surfactant or a nonionic silicone surfactant is more preferred.
When blending a surfactant, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and preferably 0.01 to 0.01% by mass, based on the total amount of the organic developer. 5% by mass is more preferred.

The development process can be carried out by a known development method, such as a method in which the support is immersed in a developer for a certain period of time (dipping method), a method in which the support is heaped up on the surface of the support by surface tension, and then left for a certain period of time. (paddle method), spraying the developer onto the surface of the support (spray method), and applying the developer onto the rotating support while scanning the developer application nozzle at a constant speed. Examples include a continuous dispensing method (dynamic dispensing method), etc.

As the organic solvent contained in the rinsing liquid used for rinsing after development in the solvent development process, for example, among the organic solvents listed as organic solvents used in the organic developer, those that do not easily dissolve the resist pattern are appropriately selected. It can be used as Generally, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents is preferred, and at least one selected from alcohol solvents and ester solvents is more preferred. Preferred are alcoholic solvents, particularly preferred.
The alcoholic solvent used in the rinse solution is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched, or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol, etc. It will be done. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred.
Any one type of these organic solvents may be used alone, or two or more types may be used in combination. Further, it may be used in combination with an organic solvent other than those mentioned above or water. However, in consideration of development characteristics, the amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably 3% by mass, based on the total amount of the rinse solution. The following are particularly preferred.
Known additives can be added to the rinsing liquid as necessary. Examples of such additives include surfactants. Examples of the surfactant include those mentioned above, preferably a nonionic surfactant, and more preferably a nonionic fluorine surfactant or a nonionic silicone surfactant.
When blending a surfactant, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.5% by mass, based on the total amount of the rinse liquid. % is more preferable.

The rinsing process (cleaning process) using a rinsing liquid can be performed by a known rinsing method. Examples of the rinsing method include a method of continuously applying a rinsing liquid onto a support rotating at a constant speed (rotary coating method), a method of immersing the support in a rinsing liquid for a certain period of time (dipping method), Examples include a method of spraying a rinsing liquid onto the surface of the support (spray method).

In the resist pattern forming method of the present embodiment described above, since the resist composition according to the first aspect described above is used, a resist pattern with good etching resistance and a good shape can be obtained. Guessed.

Such a resist composition and resist pattern forming method are useful, for example, in applications requiring a thick resist film. In addition, such resist compositions and resist pattern forming methods are useful for processing multi-stage staircase structures, and by applying the present invention, it is possible to stack memory films (three-dimensionally, manufacture large-capacity memories, etc.). ) can be realized with high precision.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Preparation of resist composition>
(Examples 1 to 10, Comparative Examples 1 to 3)
Each component shown in Table 1 was mixed and dissolved to prepare a resist composition (solid content concentration: 30% by mass) of each example.

In Table 1, each abbreviation has the following meaning. The numbers in brackets are the amount (parts by mass).
(A)-1: A polymer compound represented by the following chemical formula (A1-1). The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 10,000, and the molecular weight dispersity (Mw/Mn) was 2.14. The copolymer composition ratio (ratio (mole ratio) of each structural unit in the structural formula) determined by ¹³ C-NMR was l/m/n=61/14/25.

(B1)-1: A compound represented by the following chemical formula (B1-1).

(Z1)-1: A compound represented by the following chemical formula (Z1-1). Mass average molecular weight (Mw) is 268.35.
(Z1)-2: A compound represented by the following chemical formula (Z1-2). Mass average molecular weight (Mw) is 424.53.
(Z1)-3: A compound represented by the following chemical formula (Z1-3). Mass average molecular weight (Mw) is 352.43.
(Z1)-4: A compound represented by the following chemical formula (Z1-4). Mass average molecular weight (Mw) is 246.31.
(Z1)-5: A compound represented by the following chemical formula (Z1-5). Mass average molecular weight (Mw) is 292.29.

(Z2)-1: A compound represented by the following chemical formula (Z1-1). Mass average molecular weight (Mw) is 953.21.
(Z2)-2: A compound represented by the following chemical formula (Z1-2). Mass average molecular weight (Mw) is 827.1.

(S)-1: A mixed solvent of propylene glycol monomethyl ether acetate/propylene glycol monomethyl ether (mass ratio 50/50).

<Method for forming resist pattern>
Step (i):
Each resist composition was applied using a spinner onto a silicon substrate treated with hexamethyldisilazane (HMDS), and pre-baked (PAB) was performed at 90°C for 120 seconds on a hot plate. By drying, a resist film having a thickness of 5.0 μm was formed.
Step (ii):
Next, a high-pressure mercury lamp (365 nm) was applied to the resist film using an i-line stepper (reduction projection exposure apparatus: NSR-2205i14E (manufactured by Nikon Corporation; NA (numerical aperture) = 0.57, σ = 0.67)). , selectively irradiated through a mask pattern (6% halftone).
Then, post-exposure heating (PEB) treatment was performed at 110° C. for 60 seconds.
Process (iii):
Next, alkaline development was performed at 23°C for 60 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developer. Ta.
Thereafter, baking treatment (post-baking) was performed at 100° C. for 60 seconds.
As a result, an isolated line pattern (hereinafter referred to as "IS pattern") with a space width of 3 μm and a pitch of 15 μm was formed.

<Dry etching resistance evaluation>
The IS pattern formed by the resist pattern forming method described above was dry etched using an etching apparatus manufactured by Tokyo Ohka Kogyo under the following conditions.
conditions:
Type and flow rate of etching gas: Tetrafluoromethane 30cc/min. and trifluoromethane 30cc/min. and helium 100cc/min. Mixed gas pressure: 300mmTorr
Output: 600w
Time: 120 seconds The cross-sectional shape of the IS pattern after dry etching was observed with a scanning electron microscope (product name: S4500; manufactured by Hitachi, Ltd.), and the presence or absence of undercut (etching at the bottom of the pattern) was evaluated. The results are shown in Table 2.

<Wet etching resistance evaluation>
A part of the substrate on which the IS pattern was formed by the resist pattern forming method described above was cut out and immersed in 23% buffered hydrofluoric acid for 12 minutes.
The cross-sectional shape of the IS pattern after dipping was observed with a scanning electron microscope (product name: S4500; manufactured by Hitachi, Ltd.), and the amount of side etching (μm) was evaluated. The results are shown in Table 2.

(Evaluation of pattern film loss)
The resist composition of each example was applied onto an 8-inch silicon wafer using a spinner, pre-baked (PAB) was performed at 120°C for 90 seconds on a hot plate, and dried to determine the film thickness. A resist film of 5.0 μm was formed.
Next, the resist film was developed at 23°C for 60 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developer. Alkaline development was performed using.
Thereafter, spin coating was performed to dry the resist film, and the film thickness (nm) of the resist film was measured using Nanospec 6100A (manufactured by Nanometrics). The results are shown in Table 2.

From the results shown in Table 2, when resist patterns were formed using the resist compositions of Examples 1 to 10 to which the present invention was applied, film thinning of the pattern was suppressed, and both dry etching resistance and wet etching resistance were improved. It was also confirmed that the condition was good.

Claims (6)

A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid,
a base component (A) whose solubility in a developer changes due to the action of an acid;
A dissolution inhibitor (Z) that suppresses solubility in the developer,
Contains
The dissolution inhibitor (Z) is
A compound (Z1) represented by the following general formula (z1-1) or (z1-2) and having a mass average molecular weight of 3000 or less and having a phenolic hydroxyl group or carboxyl group in the molecule,
A compound (Z2) having a mass average molecular weight of 3000 or less and represented by the following general formula (z2),
A resist composition comprising:

[In formula (z1-1), V _z ¹ is a divalent linking group. n11 and n12 are each independently an integer of 1 to 3. In formula (z1-2), Rz ² is a hydrocarbon group. n21 is 1 or 2. n22 is an integer from 2 to 5. However, n21+n22≦6. ]

[In the formula, R _z ²⁰ is an acid dissociable group. R _z ³⁰ is a hydrogen atom or an organic group. n1 is an integer from 1 to 6, and n2 is an integer from 0 to 5. However, n1+n2=6. ] The resist composition according to claim 1, wherein the compound (Z1) is a compound represented by the following general formula (z1-1-1) or ( z1-2-1 ) .

[In the formula, R _z ¹¹ and R _z ¹² are each independently a hydrogen atom or a hydrocarbon group which may have a substituent. R _z ¹¹ and R _z ¹² may be bonded to each other to form a ring. n11 and n12 are each independently an integer of 1 to 3. ]

[In the formula, Rz ²¹ and Rz ²² are each independently an aromatic hydrocarbon group. ] The resist composition according to claim 1 or 2, wherein the compound (Z2) is a compound represented by the following general formula (z2-1) or (z2-2).

[In the formula, V _z ² is a divalent linking group. R _z ²⁰ and R _z ³³ are each independently an acid dissociable group. R _z ³¹ and R _z ³² each independently represent an organic group. R _z ²⁵ and R _z ²⁶ each independently represent a hydrogen atom or a hydrocarbon group which may have a substituent. n11 is an integer from 1 to 4. n12 is an integer from 1 to 4. However, n11+n12=5. n13 is an integer from 1 to 4. n14 is an integer from 1 to 4. However, n13+n14=5. ] The resist composition according to any one of claims 1 to 3, wherein the content of the dissolution inhibitor (Z) is 30 parts by mass or less based on 100 parts by mass of the base component (A). The blending ratio (mass ratio) of the compound (Z1) and the compound (Z2) is
The resist composition according to any one of claims 1 to 4, wherein Z1:Z2=75:25 to 25:75. A step (i) of forming a resist film on a support using the resist composition according to any one of claims 1 to 5, a step (ii) of exposing the resist film, and a step (ii) of exposing the resist film to light. A resist pattern forming method comprising a step (iii) of developing a resist film to form a resist pattern.