JP5520569B2 - Resist composition and resist pattern forming method - Google Patents

Description

  The present invention relates to a novel polymer compound that can be used as an additive for a resist composition, a compound useful as a monomer for the polymer compound, a resist composition having good lithography characteristics and a good resist pattern shape, And a resist pattern forming method using the resist composition.

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 to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film.
A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.

Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions.
As a resist material satisfying such requirements, a chemically amplified resist composition containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. ing.
For example, as a positive chemically amplified resist composition, a composition containing a resin component (base resin) whose solubility in an alkaline developer is increased by the action of an acid and an acid generator component is generally used. Yes. When such a resist film formed using the resist composition is selectively exposed at the time of forming the resist pattern, an acid is generated from the acid generator in the exposed portion, and the alkali developer of the resin component is generated by the action of the acid. As a result, the exposed area becomes soluble in an alkaline developer.
Currently, as a resist base resin used in ArF excimer laser lithography and the like, a resin having a constitutional unit derived from (meth) acrylic acid ester (acrylic resin) because of its excellent transparency near 193 nm ) And the like are generally used (see, for example, Patent Document 1). Here, “(meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position. “(Meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.

As one of the methods for further improving the resolution, exposure (immersion exposure) is performed by interposing a liquid (immersion medium) having a higher refractive index than air between the objective lens of the exposure machine and the sample. A so-called immersion lithography (hereinafter referred to as “immersion exposure”) is known (for example, see Non-Patent Document 1).
According to immersion exposure, even when a light source having the same exposure wavelength is used, the same high resolution as when using a light source with a shorter wavelength or using a high NA lens can be achieved, and the depth of focus can be reduced. It is said that there is no decline. Moreover, immersion exposure can be performed using an existing exposure apparatus. For this reason, immersion exposure is expected to be able to form resist patterns with low cost, high resolution, and excellent depth of focus. In particular, in terms of lithography characteristics such as resolution, the semiconductor industry is attracting a great deal of attention.
Immersion exposure is effective in forming all pattern shapes, and can be combined with super-resolution techniques such as the phase shift method and the modified illumination method that are currently under investigation. Currently, as an immersion exposure technique, a technique mainly using an ArF excimer laser as a light source is being actively researched. Currently, water is mainly studied as an immersion medium.

In recent years, with respect to fluorine-containing compounds, their water repellency, transparency and other characteristics have attracted attention, and research and development in various fields has been actively conducted. For example, in the field of resist materials, acid instability such as a methoxymethyl group, tert-butyl group, tert-butyloxycarbonyl group, etc. is added to a fluorine-containing polymer compound for use as a base resin of a positive chemically amplified resist. Introducing groups. However, when such a fluorine-based polymer compound is used as a base resin for a positive resist composition, there are disadvantages such as generation of a large amount of outgas after exposure and insufficient resistance to dry etching gas (etching resistance). is there.
Recently, it has been reported that an excellent pattern shape is exhibited by using a fluorine-containing polymer compound having an ester bond [—C (═O) —O—] in a resist composition (for example, Patent Documents). 2-3)

JP 2003-241385 A JP 2009-0119199 A US Publication No. 2009-0197204

Proceedings of SPIE, 5754, 119-128 (2005).

In the future, there is a demand for new materials that can be used for lithography applications as further advancement of lithography technology and expansion of application fields are expected. For example, as the pattern becomes finer, the resist material is also required to improve various lithography characteristics.
In addition, the fluorine-containing polymer compound having an ester bond [—C (═O) —O—] as described in Patent Documents 2 to 3 is PGME (propylene glycol monomethyl ether) or the like that is generally used at present. When dissolved in an alcohol-based organic solvent, the ester bond is hydrolyzed and a hydrophilic group is generated, which causes a problem in storage stability.
Furthermore, the fluorine-containing polymer compound having an ester bond [—C (═O) —O—] as described above is hydrolyzed by a strongly basic amine such as an alkylamine used as a quencher. However, since a hydrophilic group is generated, there is a problem that an amine having a strong basicity cannot be used, and an improvement thereof has been demanded.
The present invention has been made in view of the above circumstances, and is a novel polymer compound that can be used as an additive for a resist composition, a compound that is useful as a monomer of the polymer compound, has good lithography characteristics, and is formed. It is an object of the present invention to provide a resist composition having a good resist pattern shape and a resist pattern forming method using the resist composition.

In order to solve the above problems, the present invention employs the following configuration.
That is, the first aspect of the present invention includes a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, an acid generator component (B) that generates an acid upon exposure, and an alkaline developer. Is a resist composition obtained by dissolving a fluorine-containing polymer compound (C) exhibiting decomposability in an organic solvent (S), wherein the fluorine-containing polymer compound (C) has the following general formula ( The structural unit (c0-1) represented by c0-1) or the structural unit (c0-2) represented by the following general formula (c0-2), and the organic solvent (S) A resist composition comprising an alcohol-based organic solvent represented by the formula (s-0).

［式中、Ｒはそれぞれ独立に、水素原子、炭素数１〜５のアルキル基、または炭素数１〜５のハロゲン化アルキル基であり、Ｘはフッ素原子を有していてもよい２価の連結基であり、Ａ_ａｒｙｌは、置換基を有していてもよい芳香族環式基であり、Ｘ_０１は単結合またはフッ素原子を有していてもよい２価の連結基であり、Ｒ^２は、炭素数１〜１０の炭化水素基であって、該炭化水素基の水素原子が水酸基で置換されていてもよく、該炭化水素基のＣＨ_２がカルボニル基または酸素原子で置換されていてもよい。なお、式（ｃ０−１）及び式（ｃ０−２）におけるＲ ^２ は、式（ｓ−０）で表されるアルコール系有機溶剤におけるＲ ^２ と共通の基である。］

[Wherein, each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and X is a divalent alkyl group that may have a fluorine atom. A linking group, A _aryl is an aromatic cyclic group which may have a substituent, X ₀₁ is a divalent linking group which may have a single bond or a fluorine atom, R R ² is a hydrocarbon group having 1 to 10 carbon atoms, wherein the hydrogen atom of the hydrocarbon group may be substituted with a hydroxyl group, and CH ₂ of the hydrocarbon group is substituted with a carbonyl group or an oxygen atom. May be. Incidentally, ^{R 2} in the formula (C0-1) and formula (C0-2) is a common radical and ^{R 2} in an alcoholic solvent represented by the formula (s-0). ]

  According to a second aspect of the present invention, there is provided a step of forming a resist film on a support using the resist composition of the first aspect, a step of exposing the resist film, and an alkali developing of the resist film to form a resist It is a resist pattern formation method including the process of forming a pattern.

The third aspect (reference example) of the present invention is a compound represented by any one of the following general formulas (1) to (10).

［式中、Ｘはフッ素原子を有していてもよい２価の連結基であり、Ａ_ａｒｙｌは、置換基を有していてもよい芳香族環式基であり、Ｘ_０１は単結合またはフッ素原子を有していてもよい２価の連結基である。］

[Wherein, X is a divalent linking group optionally having a fluorine atom, A _aryl is an aromatic cyclic group optionally having a substituent, and X ₀₁ is a single bond or It is a divalent linking group which may have a fluorine atom. ]

The 4th aspect (reference example) of this invention is a high molecular compound containing the structural unit represented by any one of the following general formula (11)-(20).

［式中、Ｒはそれぞれ独立に、水素原子、炭素数１〜５のアルキル基、炭素数１〜５のハロゲン化アルキル基であり、Ｘはフッ素原子を有していてもよい２価の連結基であり、Ａ_ａｒｙｌは、置換基を有していてもよい芳香族環式基であり、Ｘ_０１は単結合またはフッ素原子を有していてもよい２価の連結基である。］

[Wherein, R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and X is a divalent linkage optionally having a fluorine atom. A _aryl is an aromatic cyclic group which may have a substituent, and X ₀₁ is a divalent linking group which may have a single bond or a fluorine atom. ]

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the 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 part or all of the hydrogen atoms of an alkyl group or alkylene group are substituted with fluorine atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include those in which a hydrogen atom is bonded to the carbon atom at the α-position, and those in which a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom in the α-position. Include concepts. Examples of the substituent bonded to the α-position carbon atom include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
In the acrylic ester, the alkyl group having 1 to 5 carbon atoms as the substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl C1-C5 linear or branched alkyl groups, such as a group, a pentyl group, an isopentyl group, and a neopentyl group.
Further, as the halogenated alkyl group having 1 to 5 carbon atoms, specifically, a part or all of the hydrogen atoms in the above-mentioned “alkyl group having 1 to 5 carbon atoms as a substituent at the α-position” are substituted with halogen atoms. Group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. It is more preferably a C 1-5 alkyl group or a C 1-5 fluorinated alkyl group, and most preferably a hydrogen atom or a methyl group in terms of industrial availability.
“Exposure” is a concept including general irradiation of radiation.
“Degradable with respect to alkali developer” means that it is decomposed by the action of an alkali developer (preferably at 23 ° C. by the action of a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution. This means that the solubility in an alkaline developer is increased.

  According to the present invention, a novel polymer compound that can be used as an additive for a resist composition, a compound that is useful as a monomer for the polymer compound, a resist composition having good lithography characteristics and a good resist pattern shape And a resist pattern forming method using the resist composition.

It is a figure explaining advancing angle ((theta) ₁ ), receding angle ((theta) ₂ ), and falling angle ((theta) ₃ ).

≪Resist composition≫
The resist composition of the present invention comprises a base component (A) whose solubility in an alkaline developer is changed by the action of an acid (hereinafter referred to as “component (A)”), and an acid generator that generates an acid upon exposure. Component (B) (hereinafter referred to as “component (B)”) and fluorine-containing polymer compound (C) (hereinafter referred to as “component (C)”) exhibiting degradability with respect to an alkaline developer. And dissolved in an organic solvent (S) (hereinafter referred to as “component (S)”).
When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the component (B), and the acid has a solubility in the alkaline developer of the component (A). Change. As a result, while the solubility of the exposed portion of the resist film in the alkaline developer changes, the unexposed portion does not change the solubility in the alkaline developer. In the case of the negative type, the unexposed part is dissolved and removed, and a resist pattern is formed.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
“Substrate component” means an organic compound having film-forming ability.
As the component (A), an organic compound having a molecular weight of 500 or more is usually used. When the molecular weight is 500 or more, it has a sufficient film forming ability and can easily form a nano-level resist pattern.
“Organic compounds having a molecular weight of 500 or more” are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the “low molecular compound” refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, those having a molecular weight of 1000 or more are usually used. Hereinafter, the term “resin” refers to a polymer having a molecular weight of 1000 or more. In the case of a resin, a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used as the “molecular weight”.
As the component (A), a resin may be used, a low molecular compound may be used, or these may be used in combination.

When the resist composition of the present invention is a negative resist composition, as the component (A), a base component soluble in an alkali developer is used, and a crosslinking agent is further blended.
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause crosslinking between the base material component and the crosslinking agent, resulting in poor solubility in an alkali developer. To do. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the negative resist composition on the substrate is selectively exposed, the exposed portion turns into poorly soluble in an alkaline developer, while unexposed. Since the portion remains soluble in the alkali developer and does not change, a resist pattern can be formed by alkali development.
As the component (A) of the negative resist composition, a resin that is soluble in an alkali developer (hereinafter referred to as an alkali-soluble resin) is usually used.
Examples of the alkali-soluble resin include α- (hydroxyalkyl) acrylic acid or alkyl esters of α- (hydroxyalkyl) acrylic acid (preferably alkyl having 1 to 5 carbon atoms) disclosed in JP-A No. 2000-206694. Resin having a unit derived from at least one selected from ester), (meth) acrylic resin or polycycloolefin resin having a sulfonamide group, disclosed in US Pat. No. 6,949,325, US Pat. (Meth) acrylic resin containing a fluorinated alcohol, disclosed in JP-A No. 2005-336442, JP-A-2006-317803, and polycycloolefin resin having a fluorinated alcohol disclosed in JP-A-2006-259582 Etc. Good with little swelling A resist pattern can be formed, which is preferable.
The α- (hydroxyalkyl) acrylic acid is composed of acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having a carbon number) in the α-position carbon atom. One or both of α-hydroxyalkylacrylic acid to which 1-5 hydroxyalkyl groups) are bonded.
As the crosslinking agent, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, a melamine crosslinking agent, or the like because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

  When the resist composition of the present invention is a positive resist composition, as the component (A), a base material component whose solubility in an alkaline developer is increased by the action of an acid is used. The substrate component is hardly soluble in an alkali developer before exposure, and when an acid is generated from the component (B) by exposure, the solubility in the alkali developer is increased by the action of the acid. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the positive resist composition on the substrate is selectively exposed, the exposed portion changes from poorly soluble to soluble in an alkaline developer. On the other hand, since the unexposed portion remains hardly soluble in alkali and does not change, a resist pattern can be formed by alkali development.

In the resist composition of the present invention, the component (A) is preferably a base material component whose solubility in an alkaline developer is increased by the action of an acid. That is, the resist composition of the present invention is preferably a positive resist composition.
The component (A) may be a resin component (A1) (hereinafter also referred to as component (A1)) whose solubility in an alkaline developer is increased by the action of an acid. It may be a low molecular compound (A2) (hereinafter sometimes referred to as the component (A2)) whose solubility in a liquid is increased, or a mixture thereof. Especially, it is preferable that this (A) component contains (A1) component.

[(A1) component]
As the component (A1), resin components (base resins) that are usually used as base components for chemically amplified resists can be used alone or in combination of two or more.
In the present invention, the component (A1) preferably has a structural unit derived from an acrylate ester.
In the resist composition of the present invention, it is particularly preferable that the component (A1) has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
In addition to the structural unit (a1), the component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
The component (A1) is derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a1) or in addition to the structural units (a1) and (a2). It is preferable to have a structural unit (a3).

(Structural unit (a1))
The structural unit (a1) is a structural unit derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire component (A1) difficult to dissolve in an alkali developer before dissociation, and dissociates with an acid. This increases the solubility of the entire component in an alkaline developer, and those that have been proposed as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists can be used. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. .

Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (═O ) -O-) shows a structure in which the tertiary carbon atom of the chain-like or cyclic alkyl group is bonded to the terminal oxygen atom. In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.
Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.

Here, the term “aliphatic branched” in the claims and the specification means having a branched structure having no aromaticity.
The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group.
The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferable, and specific examples include a tert-butyl group, a tert-pentyl group, and a tert-heptyl group. .

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like. Is mentioned.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include a monocycloalkane, a bicycloalkane, and a tricyclo which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated alkyl group. Examples thereof include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as an alkane or tetracycloalkane. More specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .

  Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Specifically, 2-methyl-2 -Adamantyl group, 2-ethyl-2-adamantyl group, etc. are mentioned. Alternatively, in the structural units represented by the following general formulas (a1 ″ -1) to (a1 ″ -6), an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (—C (O) —O—) A group having an aliphatic cyclic group such as a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecyl group, or a tetracyclododecyl group and a branched alkylene group having a tertiary carbon atom bonded thereto. Can be mentioned.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し；Ｒ^１５、Ｒ^１６はアルキル基（直鎖状、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

In the formula, R represents a hydrogen atom, a halogenated alkyl group of 1 to 5 alkyl group or a C1-5 carbon; R ^15, R ¹⁶ is an alkyl group (straight, any branched Well, preferably 1 to 5 carbon atoms). ]

  In the general formulas (a1 ″ -1) to (a1 ″ -6), the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms of R is bonded to the α-position of the acrylate ester. And the same as the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms.

The “acetal acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表し、ｎは０〜３の整数を表し、Ｙは炭素数１〜５のアルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl group having 1 to 5 carbon atoms. Or represents an aliphatic cyclic group. ]

In the above formula, n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group having 1 to 5 carbon atoms of R ¹ ′ and R ² ′ include those similar to the alkyl group having 1 to 5 carbon atoms of R, preferably a methyl group or an ethyl group, and most preferably a methyl group. preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable, dissolution inhibiting group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

[Wherein R ¹ ′, n and Y are the same as described above. ]

Examples of the alkyl group having 1 to 5 carbon atoms of Y include the same as the alkyl group having 1 to 5 carbon atoms of R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists, for example, the “aliphatic ring” described above. Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable, dissolution inhibiting group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状または分岐鎖状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐鎖状または環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represent a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group. In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, are included. Examples include a group excluding a hydrogen atom. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ¹⁹ and R ¹⁷ The terminal may be bonded.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  As the structural unit (a1), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し、Ｘ^１は酸解離性溶解抑制基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and X ¹ represents an acid dissociable, dissolution inhibiting group. ]

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し、Ｘ^２は酸解離性溶解抑制基を示し、Ｙ^２は２価の連結基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, X ² represents an acid dissociable, dissolution inhibiting group, and Y ² represents a divalent linkage. Indicates a group. ]

In the general formula (a1-0-1), the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms of R may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group having ˜5 or the halogenated alkyl group having 1 to 5 carbon atoms.
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. And tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred.

In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).

Examples of the divalent linking group for Y ² include an alkylene group, a divalent aliphatic cyclic group, and a divalent linking group containing a hetero atom.
As the aliphatic cyclic group, those similar to the explanation of the “aliphatic cyclic group” can be used except that a group in which two or more hydrogen atoms are removed is used.
When Y ² is an alkylene group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and 1 to 3 carbon atoms. Most preferably it is.
When Y ² is a divalent aliphatic cyclic group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable. .
When Y ² is a divalent linking group containing a hetero atom, examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, —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—, “—AO (oxygen atom) —B— (wherein A and B each independently have a substituent) And a combination of an alkylene group and a divalent linking group containing a hetero atom.

When Y ² is —NH—, the substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 5 carbon atoms. It is particularly preferred that
When Y ² is “A—O—B”, A and B are each independently a divalent hydrocarbon group which may have a substituent.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.

  The hydrocarbon group in A may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.

The aliphatic hydrocarbon group for A may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for A include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 2 to 5, and most preferably 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, 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 - ; alkylethylene groups such as - Alkylethylene groups such as CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —; Alkyl trimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH _{3) CH} 2 CH ₂ - alkyl, such as alkyl tetramethylene group such as Such as an alkylene group, and the like. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like 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, an oxygen atom (= O), and the like.

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group described above as a chain-like aliphatic group. And a group that is bonded to the terminal of the aromatic hydrocarbon group or intervenes in the middle of the chain-like aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane.
As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

  A is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 2 to 5 carbon atoms, and most preferably an ethylene group.

Examples of the hydrocarbon group for B include the same divalent hydrocarbon groups as those described above for A.
B is preferably a linear or branched aliphatic hydrocarbon group, particularly preferably a methylene group or an 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.

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５のアルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；Ｙ^２は２価の連結基を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester-type acid dissociable, dissolution inhibiting group, Y represents an alkyl group having 1 to 5 carbon atoms or an aliphatic cyclic group; n represents an integer of 0 to 3; Y ² represents a divalent linking group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ]

In the formula, X 'include the same tertiary alkyl ester-type acid dissociable, dissolution inhibiting groups as those described above for X ^{1.
R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable, dissolution inhibiting group" described above ^{(p1) ', R 2'} , n, Y The same thing is mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).

Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.
In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
Among these, the structural unit represented by general formula (a1-1), (a1-2) or (a1-3) is preferable, and specifically, (a1-1-1) to (a1-1-4). , (A1-1-20) to (a1-1-23), (a1-2-1) to (a1-2-24) and (a1-3-25) to (a1-3-28) It is more preferable to use at least one selected from the group.
Furthermore, as the structural unit (a1), in particular, the following general formula (a1-1-1-) including structural units of the formulas (a1-1-1) to (a1-1-3) and (a1-1-26) 01), formulas (a1-1-16) to (a1-1-17) and formulas (a1-1-20) to (a1-1-23) What is represented by (a1-1-02), which is represented by the following general formula (a1-3-01) including the structural units of formulas (a1-3-25) to (a1-3-26) The following general formula (a1-3-02) or the formulas (a1-3-29) to (a1-3-30) including the structural units of the formulas (a1-3-27) to (a1-3-28) The structural unit represented by the following general formula (a1-3-03) including the structural unit is also preferable.

[式中、Ｒはそれぞれ独立に水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し、Ｒ^１１は炭素数１〜５のアルキル基を示す。Ｒ^１２は炭素数１〜７のアルキル基を示す。ｈは１〜６の整数を表す。]

[Wherein, R independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R ¹¹ represents an alkyl group having 1 to 5 carbon atoms. R ¹² represents an alkyl group having 1 to 7 carbon atoms. h represents an integer of 1 to 6. ]

In general formula (a1-1-01), R is the same as defined above. The alkyl group having 1 to 5 carbon atoms of R ¹¹ is the same as the alkyl group having 1 to 5 carbon atoms in R, and is preferably a methyl group, an ethyl group, or an isopropyl group.

In general formula (a1-1-02), R is the same as defined above. The alkyl group having 1 to 5 carbon atoms of R ¹² is the same as the alkyl group having 1 to 5 carbon atoms in R, and is preferably a methyl group, an ethyl group, or an isopropyl group. h is preferably 1 or 2, and most preferably 2.

[式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し；Ｒ^１４は炭素数１〜５のアルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数である。]

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁴ represents an alkyl group having 1 to 5 carbon atoms, and R ¹³ represents a hydrogen atom. Or it is a methyl group and a is an integer of 1-10. ]

[式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を示し；Ｒ^１４は炭素数１〜５のアルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数であり、ｎ’は１〜６の整数である。]

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁴ represents an alkyl group having 1 to 5 carbon atoms, and R ¹³ represents a hydrogen atom. Or it is a methyl group, a is an integer of 1-10, n 'is an integer of 1-6. ]

［式中、Ｒは前記と同じであり、Ｙ^２’およびＹ^２”はそれぞれ独立して２価の連結基であり、Ｘ’は酸解離性溶解抑制基であり、ｎは０〜３の整数である。］

[Wherein, R is the same as defined above, Y ² ′ and Y ² ″ each independently represent a divalent linking group, X ′ represents an acid dissociable, dissolution inhibiting group, and n represents 0 to 3] It is an integer.]

In the general formulas (a1-3-01) to (a1-3-03), R is the same as described above.
R ¹³ is preferably a hydrogen atom.
Alkyl group of 1 to 5 carbon atoms for R ¹⁴ is the same as the alkyl group having 1 to 5 carbon atoms for R, a methyl group or an ethyl group is preferred.
n ′ is preferably 1 or 2, and most preferably 2.
a is preferably an integer of 1 to 8, more preferably an integer of 2 to 5, and most preferably 2.
As the divalent linking group for Y ² ′ and Y ² ″, the same groups as those described above for Y ² in formula (a1-3) can be given.
Y ² ′ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and even more preferably a linear alkylene group. Among these, a linear alkylene group having 1 to 5 carbon atoms is preferable, and a methylene group and an ethylene group are most preferable.
Y ² ″ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and still more preferably a linear alkylene group. A linear alkylene group of 1 to 5 is preferable, and a methylene group and an ethylene group are most preferable.
Examples of the acid dissociable, dissolution inhibiting group in X ′ include the same groups as described above, and are preferably tertiary alkyl ester type acid dissociable, dissolution inhibiting groups, and (i) the monovalent aliphatic cyclic group described above. A group having a tertiary carbon atom on the ring skeleton of the group is more preferable, and among them, the group represented by the general formula (1-1) is preferable.
n is an integer of 0 to 3, and n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.

  In the component (A1), the proportion of the structural unit (a1) is preferably from 5 to 80 mol%, more preferably from 10 to 80 mol%, more preferably from 15 to 75 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

(Structural unit (a2))
The structural unit (a2) is a structural unit derived from an acrylate ester containing a lactone-containing cyclic group.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring, and when it is only the lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
When the component (A1) is used for forming a resist film, the lactone cyclic group of the structural unit (a2) increases the adhesion of the resist film to the substrate or has an affinity for a developer containing water. It is effective in raising.
As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, the lactone-containing monocyclic group is a group in which one hydrogen atom is removed from a 4- to 6-membered ring lactone, such as a group in which one hydrogen atom is removed from β-propiolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed, and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) shown below.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；Ｒ’はそれぞれ独立に水素原子、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、Ｒ”は水素原子またはアルキル基であり；Ｒ^２９は単結合または２価の連結基であり、ｓ”は０〜２の整数であり；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；ｍは０または１である。］

[Wherein, 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; R ′ is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, carbon An alkoxy group of 1 to 5 or —COOR ″, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group, and s ″ is an integer of 0 to 2; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom; m is 0 or 1. ]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a0).
Examples of the alkyl group having 1 to 5 carbon atoms of R ′ include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms of R ′ include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.
R ′ is preferably a hydrogen atom in view of industrial availability.
The alkyl group in R ″ may be linear, branched or cyclic.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
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, a fluorine atom Or a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
Examples of A ″ include the same as A ′ in the general formula (3-1). A ″ represents an alkylene group having 1 to 5 carbon atoms, an oxygen atom (—O—) or a sulfur atom (— S-) is preferable, and an alkylene group having 1 to 5 carbon atoms or -O- is more preferable. The alkylene group having 1 to 5 carbon atoms is more preferably a methylene group or dimethylmethylene group, and most preferably a methylene group.

R ²⁹ is a single bond or a divalent linking group. As a bivalent coupling group, the thing similar to the bivalent coupling group demonstrated by R < ² > in the said general formula (a0-1) is mentioned. Among these, an alkylene group, an ester bond (—C (═O) —O—), or a combination thereof is preferable. The alkylene group as the divalent linking group for R ²⁹ is more preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group for R ² can be used.
As R ²⁹ , in particular, a single bond or —R ²⁹ ′ —C (═O) —O— [wherein R ²⁹ ′ is a linear or branched alkylene group. ] Is preferable.
The linear or branched alkylene group for R ²⁹ ′ preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 1 to 5, particularly preferably 1 to 3. ~ 2 is most preferred.
As the linear alkylene group for R ²⁹ ′, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable. The branched alkylene group for R ²⁹ ′ is preferably an alkylmethylene group or an alkylethylene group, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — Is particularly preferred.
In formula (a2-1), s ″ is preferably 1 to 2.
Specific examples of the structural units represented by the general formulas (a2-1) to (a2-5) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

In the component (A1), as the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
In the present invention, the component (A1) is at least one selected from the group consisting of structural units represented by any one of the general formulas (a2-1) to (a2-5) as the structural unit (a2). It is preferable that at least one selected from the group consisting of structural units represented by any one of the general formulas (a2-1) to (a2-3) is more preferable. It is particularly preferable to have at least one selected from the group consisting of structural units represented by 1) or (a2-2).

  The proportion of the structural unit (a2) in the component (A1) is such that the resist film formed using the positive resist composition containing the component (A1) adheres to a support such as a substrate, and the developer. From the viewpoint of excellent affinity, etc., it is preferably 5 to 70 mol%, more preferably 10 to 65 mol%, more preferably 15 to 65 mol%, based on the total of all structural units constituting the component (A1). Is more preferable, and 20 to 60 mol% is most preferable. By setting it as the above range, MEF and pattern shape are further improved, and CDU is also improved.

(Structural unit (a3))
The structural unit (a3) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
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 polycyclic aliphatic hydrocarbon group (polycyclic group). It is done.
As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid 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. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the following formula (a3-2), and the following formula The structural unit represented by (a3-3) is preferable.

[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。]

[Wherein, R is as defined 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 of 1 to 3. ]

In formula (a3-1), j is preferably 1 or 2, and 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.
j is preferably 1, and a hydroxyl group bonded to the 3-position of the adamantyl group is particularly preferred.

  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. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a3) is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on all structural units constituting the component (A1). More preferred is ˜40 mol%. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

(Other structural units)
The component (A1) may contain other structural units (hereinafter referred to as structural unit (a4)) other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1) to (a3) described above, and is for ArF excimer laser and KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
Examples of the structural unit (a4) include a structural unit derived from an acrylate ester containing a non-acid dissociable aliphatic polycyclic group, a structural unit derived from a styrene monomer, and a vinyl naphthalene monomer. preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms 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 those represented by the following general formulas (a4-1) to (a4-5).

［式中、Ｒは前記と同じである。］

[Wherein, R is the same as defined above. ]

As the structural unit (a4), one type may be used alone, or two or more types may be used in combination.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 20 mol% with respect to the total of all the structural units constituting the component (A1). 15 mol% is more preferable and 1-10 mol% is further more preferable.

The component (A1) is preferably a copolymer having the structural unit (a1).
Examples of such a copolymer include a copolymer composed of the structural unit (a1) and the structural unit (a3); a copolymer composed of the structural units (a1), (a2) and (a3).
In the present invention, the component (A1) preferably includes a combination of structural units represented by the following general formulas (A1-11) and (A1-12).

［式中、Ｒ、Ｒ^２９、ｓ”、Ｒ^１２、ｈ、ｊはそれぞれ前記と同じであり、式中に複数あるＲは、同じであっても異なっていてもよい。］

[Wherein R, R ²⁹ , s ″, R ¹² , h, j are the same as defined above, and a plurality of R in the formula may be the same or different.]

［式中、Ｒ、Ｒ^２９、ｓ”、Ｒ^１１、ｊはそれぞれ前記と同じであり、式中に複数あるＲは、同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , s ″, R ¹¹ and j are the same as defined above, and a plurality of R in the formula may be the same or different.]

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, most preferably 2500 to 20000. preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.2 to 2 .5 is most preferred.
Mn represents a number average molecular weight.

In the component (A), as the component (A1), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, and 100% by mass with respect to the total mass of the component (A). May be. When the ratio is 25% by mass or more, the effects such as lithography characteristics are improved.

[(A2) component]
The component (A2) is preferably a low molecular compound having a molecular weight of 500 or more and less than 2500 and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of the component (A1). Specifically, a compound in which a part of hydrogen atoms of a hydroxyl group of a compound having a plurality of phenol skeletons is substituted with the acid dissociable, dissolution inhibiting group can be mentioned.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a soluble dissolution inhibiting group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2 to 6 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol and xylenol. Of course, it is not limited to these. In particular, a phenol compound having 2 to 6 triphenylmethane skeletons is preferable because of excellent resolution and LWR.
The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.
(A2) A component may be used individually by 1 type and may be used in combination of 2 or more type.

In the resist composition of the present invention, as the component (A), one type may be used alone, or two or more types may be used in combination.
Among the above, the component (A) preferably contains the component (A1).
In the resist composition of the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<(B) component>
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^４”は、置換基を有していても良いアルキル基、ハロゲン化アルキル基、アリール基、またはアルケニル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; among R ¹ ″ to R ³ ″ in formula (b-1), Any two may be bonded to each other to form a ring together with the sulfur atom in the formula; R ⁴ ″ may be an optionally substituted alkyl group, halogenated alkyl group, aryl group, or alkenyl group; And at least one of R ¹ ″ to R ³ ″ represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. In addition, any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Further, at least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.

The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may or may not be substituted with a group, a halogen atom, a hydroxyl group or the like.
The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, A tert-butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
The halogen atom that may be substituted with the hydrogen atom of the aryl group is preferably a fluorine atom.

The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.

When any two of R ¹ ″ to R ³ ″ in the formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, a 3 to 10 membered ring including the sulfur atom is formed. It is preferable that a 5- to 7-membered ring is formed.
When any two of R ¹ ″ to R ³ ″ in formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one may be an aryl group preferable. Examples of the aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″.

Preferable examples of the cation moiety of the compound represented by the formula (b-1) include cation moieties represented by the following formulas (I-1-1) to (I-1-10). Among these, those having a triphenylmethane skeleton such as a cation moiety represented by formulas (I-1-1) to (I-1-8) are preferable.
In the following formulas (I-1-9) to (I-1-10), R ⁹ and R ¹⁰ are each independently a phenyl group, naphthyl group or carbon number 1 to 5 which may have a substituent. An alkyl group, an alkoxy group, and a hydroxyl group.
u is an integer of 1 to 3, and 1 or 2 is most preferable.

R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.
The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.
The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.
In the above R ⁴ ″, “optionally substituted” means one of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group. It means that part or all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ⁴ ″ may be one or two or more.

Examples of the substituent include, for example, a halogen atom, a hetero atom, an alkyl group, a formula: XQ ^1- [where Q ¹ is a divalent linking group containing an oxygen atom, and X has a substituent. And a hydrocarbon group having 3 to 30 carbon atoms. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described above for R ⁴ ″ as the halogen atom and alkyl group in the halogenated alkyl group.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

X-Q 1 ^- In the group represented by, Q ¹ represents a divalent linking group containing an oxygen atom.
Q ¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond; —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —O—C (═O) — , R ^{91 to} R ⁹³ are each independently an alkylene group.) And the like.
The alkylene group for R ^{91 to} R ⁹³ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —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 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ — and the like. Alkylethylene groups; trimethylene groups (n-propylene groups) [—CH ₂ CH ₂ CH ₂ —]; alkyls such as —CH (CH ₃ ) CH ₂ CH ₂ — and —CH ₂ CH (CH ₃ ) CH ₂ — trimethylene; tetramethylene group _[-CH 2 _CH 2 C _{2 CH 2 -]; - CH} (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; pentamethylene group _[-CH 2 _CH 2 CH ₂ CH ₂ CH ₂ —] and the like.
Q ¹ is preferably a divalent linking group containing an ester bond or an ether bond, and in particular, —R ⁹¹ —O—, —R ⁹² —O—C (═O) — or —C (═O) — O—R ⁹³ —O—C (═O) — is preferred.

In the group represented by XQ ^1- , the hydrocarbon group of X may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic hydrocarbon group for X may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In X, the aliphatic hydrocarbon group may have a part of the carbon atoms constituting the aliphatic hydrocarbon group substituted by a substituent containing a hetero atom, and the hydrogen atom constituting the aliphatic hydrocarbon group May be substituted with a substituent containing a hetero atom.
The “heteroatom” in X is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, 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 a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (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, decyl 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, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group (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, 4-methylpentyl group and the like.

As an unsaturated hydrocarbon group, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms are removed from a monocycloalkane; a group in which one or more hydrogen atoms are removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and has one or more hydrogen atoms from the polycycloalkane. Excluded groups are preferred, and most preferred are groups in which one or more hydrogen atoms have been removed from adamantane.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include the following formulas (L1) to (L5), (S1) to (S4), and the like.

［式中、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[Wherein, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —, and R ⁹⁴ and R ⁹⁵ are each independently carbon. An alkylene group of 1 to 5 and m is an integer of 0 or 1.]

In the formula, examples of the alkylene group for Q ″, R ⁹⁴ and R ⁹⁵ include the same alkylene groups as those described above for R ^{91 to} R ⁹³ .
In these aliphatic cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
Examples of the alkoxy group and the halogen atom are the same as those exemplified as the substituent for substituting part or all of the hydrogen atoms.

In the present invention, X is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, (L2) to (L5), (S3) to (S4), and the like.

In the present invention, ^{R 4} ", ^{X-Q 1} - as a substituent preferably has the case, ^{R 4."} The, ^{X-Q 1} -Y 1 - in the Formula, ^{Q 1} and X are the Y ¹ is an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ] Is preferable.
In the group represented by XQ ¹ -Y ^1- , the alkylene group for Y ¹ includes the same alkylene groups as those described above for Q ¹ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^1, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ¹ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

The alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl group.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"As ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
In addition, the anion part of these onium salts may be methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, 1-adamantanesulfonate, 2-norbornanesulfonate, d-camphor-10-sulfonate, benzenesulfonate, Onium salts substituted with alkyl sulfonates such as fluorobenzene sulfonate and p-toluene sulfonate can also be used.
Moreover, the onium salt which replaced the anion part of these onium salts by the anion part represented by either of following formula (b1)-(b8) can also be used.

［式中、ｐは１〜３の整数であり、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^７は置換基であり、ｎ１〜ｎ５はそれぞれ独立に０または１であり、ｖ０〜ｖ５はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ５はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[Wherein p is an integer of 1 to 3, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 ~ R2 is each independently an integer of 0 to 3, g is an integer of 1 to 20, R ⁷ is a substituent, n1 to n5 are each independently 0 or 1, and v0 to v5 are each Each independently represents an integer of 0 to 3, w1 to w5 are each independently an integer of 0 to 3, and Q ″ is the same as defined above.]

Examples of the substituent for R ⁷ are the same as those described above as the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have in X. Can be mentioned.
Code (r1 and r2, w1 to w5) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, may be different.

  Moreover, as an onium salt type | system | group acid generator, in the said general formula (b-1) or (b-2), an anion part is represented by the following general formula (b-3) or (b-4). An onium salt-based acid generator replaced with can also be used (the cation moiety is the same as (b-1) or (b-2)).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Most preferably, it has 3 carbon atoms.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably Has 1 to 7 carbon atoms, more preferably 1 to 3 carbon atoms.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid increases, and high-energy light or electron beam of 200 nm or less The ratio of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all. Are a perfluoroalkylene group or a perfluoroalkyl group in which a hydrogen atom is substituted with a fluorine atom.

  Moreover, the sulfonium salt which has a cation part represented by the following general formula (b-5) or (b-6) can also be used as an onium salt type | system | group acid generator.

［式中、Ｒ^４１〜Ｒ^４６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[Wherein R ^{41 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{1 to} n ₅ are each independently an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

In R ^{41 to} R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, an isopropyl group, n A butyl group or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{1 to} n ₆ attached to R ^{41 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

The anion part of the sulfonium salt having a cation part represented by the formula (b-5) or (b-6) is not particularly limited, and is the same as the anion part of the onium salt acid generators proposed so far. It may be a thing. Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ^{4 ″} SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). The anion part represented by the general formula (b-3) or (b-4) and the like.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

[式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。]

[In Formula (B-1), R ³¹ and R ³² each independently represents an organic group. ]

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.
As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent for R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.
As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And heteroaryl groups in which some of the carbon atoms constituting the ring of these groups are substituted with heteroatoms such as oxygen, sulfur, and nitrogen atoms. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.
The alkyl group or halogenated alkyl group having no substituent for R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [Chemical 18] to [Chemical 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 86 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
In the present invention, it is preferable to use an onium salt acid generator having a fluorinated alkyl sulfonate ion as an anion as the component (B).
The content of the component (B) in the positive resist composition of the present invention is preferably 0.5 to 50 parts by mass and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the component (A). By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(C) component>
In the present invention, the component (C) is a fluorine-containing polymer compound that is decomposable to an alkaline developer, and is a structural unit (c0-1) represented by the following general formula (c0-1), or It has a structural unit (c0-2) represented by the following general formula (c0-2).
Hereinafter, the structural units (c0-1) and (c0-2) may be collectively referred to as “structural unit (c0)”.

［式中、Ｒはそれぞれ独立に、水素原子、炭素数１〜５のアルキル基、または炭素数１〜５のハロゲン化アルキル基であり、Ｘはフッ素原子を有していてもよい２価の連結基であり、Ａ_ａｒｙｌは、置換基を有していてもよい芳香族環式基であり、Ｘ_０１は単結合またはフッ素原子を有していてもよい２価の連結基であり、Ｒ^２は、炭素数１〜１０の炭化水素基であって、該炭化水素基の水素原子が水酸基で置換されていてもよく、該炭化水素基のＣＨ_２がカルボニル基または酸素原子で置換されていてもよい。］

[Wherein, each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and X is a divalent alkyl group that may have a fluorine atom. A linking group, A _aryl is an aromatic cyclic group which may have a substituent, X ₀₁ is a divalent linking group which may have a single bond or a fluorine atom, R R ² is a hydrocarbon group having 1 to 10 carbon atoms, wherein the hydrogen atom of the hydrocarbon group may be substituted with a hydroxyl group, and CH ₂ of the hydrocarbon group is substituted with a carbonyl group or an oxygen atom. May be. ]

In the resist composition of the present invention, by containing the component (C), in the formation of the resist pattern, it is possible to form a resist film having characteristics that are hydrophobic during immersion exposure and hydrophilic during alkali development. . The component (C) is hardly soluble in an alkali developer before being decomposed, and when decomposed by the action of the alkali developer, a carboxy group which is a hydrophilic group is generated, and the solubility in an alkali developer is increased. A compound.
In the component (C) of the present invention, when the structural unit (c0-1) or (c0-2) is not a structural unit exhibiting decomposability to an alkaline developer, the structural unit (c0-1) or (c0-2) ) Requires copolymerization with other structural units that are degradable to an alkali developer. Examples of other structural units exhibiting decomposability to the alkali developer include structural units (c21) described later.

(Structural unit (c0))
In formula (c0-1), R is the same as R in the description of the component (A) and is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. .
Specific examples of the alkyl group having 1 to 5 carbon atoms of R include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl. Examples thereof include linear or branched alkyl groups having 1 to 5 carbon atoms.
Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms for R include groups in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
R is more 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 more preferably a hydrogen atom or a methyl group.

  In the formula (c0-1), X is a divalent linking group which may have a fluorine atom. For example, a hydrocarbon group which may have a substituent, a group containing a hetero atom, or the like It is mentioned as preferable.

(Hydrocarbon group which may have a substituent)
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Such an aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

  More specifically, 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.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, more preferably 1 to 5, particularly preferably 1 to 3, and 2 Most preferred.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, 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 - ; alkylethylene groups such as - Alkylethylene groups such as CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —; Alkyl trimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH _{3) CH} 2 CH ₂ - alkyl, such as alkyl tetramethylene group such as Such as an alkylene group, and the like. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like (straight chain or branched chain) aliphatic hydrocarbon group may or may not have a substituent. Preferred examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (═O), and the like.

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the chain aliphatic aliphatic hydrocarbon group described above. Examples include a group bonded to the terminal of an aromatic hydrocarbon group or interposed in the middle of a chain aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane.
As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Preferred examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (═O).

Examples of the aromatic hydrocarbon group include aromatics of monovalent aromatic hydrocarbon groups such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. A divalent aromatic hydrocarbon group obtained by removing one hydrogen atom from the hydrocarbon nucleus;
An aromatic hydrocarbon group in which a part of carbon atoms constituting the ring of the divalent aromatic hydrocarbon group is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom;
Benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc. Aromatic hydrocarbon groups and the like removed.
Among them, the divalent aromatic hydrocarbon group is preferable, and an aromatic hydrocarbon group in which one hydrogen atom is further removed from a phenyl group, and an aromatic hydrocarbon group in which one hydrogen atom is further removed from a naphthyl group are particularly preferable. preferable.
The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
The aromatic hydrocarbon group may or may not have a substituent. Preferred examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (═O).

Among the above, the hydrocarbon group which may have a substituent is preferably a linear, branched or cyclic aliphatic hydrocarbon group, or a divalent aromatic hydrocarbon group, more preferably a methylene group. , Ethylene group, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) CF ₂ —, a group obtained by further removing one hydrogen atom from a tetracyclododecanyl group, and further removing one hydrogen atom from a phenyl group Especially preferred are aromatic hydrocarbon groups.

(Groups containing heteroatoms)
A hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
Examples of the group containing a hetero atom include -O-, -C (= O)-, -C (= O) -O-, carbonate bond (-O-C (= O) -O-), -NH. —, —NR ⁰⁴ (R ⁰⁴ is an alkyl group) —, —NH—C (═O) —, ═N—, or “one or more of these groups” and a divalent hydrocarbon group A combination etc. are mentioned.
Examples of the divalent hydrocarbon group include the same hydrocarbon groups that may have a substituent as described above, and a linear or branched aliphatic hydrocarbon group is preferable.
Among these, as the group containing a hetero atom, a combination of the “one or more of these groups” and a divalent hydrocarbon group is more preferable. Species or a combination of two or more ”and the aliphatic hydrocarbon group, and a combination of the aliphatic hydrocarbon group and the“ one or more of these groups ”and the aliphatic hydrocarbon group is particularly preferable. .

In formula (c0-1), R ² is an organic group having “R ² —OH” as an alcohol-based organic solvent. R ² is a hydrocarbon group having 1 to 10 carbon atoms, wherein the hydrogen atom of the hydrocarbon group may be substituted with a hydroxyl group, and CH ₂ of the hydrocarbon group is substituted with a carbonyl group or an oxygen atom. It may be. R ² is one obtained by removing one hydroxyl group from an alcoholic organic solvent, and is preferably one obtained by removing one hydroxyl group from an alcoholic organic solvent usually used in a resist composition.

  In the present specification and claims, an “alcohol organic solvent” is a compound in which at least one of the hydrogen atoms of an aliphatic hydrocarbon is substituted with a hydroxyl group, and is a liquid that is liquid at normal temperature and pressure Say. The structure of the main chain constituting the aliphatic hydrocarbon may be a chain structure, may be a cyclic structure, may have a cyclic structure in the chain structure, The chain structure may contain an ether bond.

Examples of the alcohol-based organic solvent include the following. As the alcohol organic solvent, monohydric alcohols, polyhydric alcohols, and derivatives of polyhydric alcohols are preferable.
Specific examples of the alcohol-based organic solvent include those having a chain structure, such as propylene glycol monomethyl ether (PGME), ethyl lactate (EL), methyl lactate, propylene glycol (PG), ethylene glycol, diethylene glycol, dipropylene glycol, 1-butoxy-2-propanol (BP), n-hexanol, 2-heptanol, 3-heptanol, 1-heptanol, 5-methyl-1-hexanol, 6-methyl-2-heptanol, 1-octanol, 2-octanol , 3-octanol, 4-octanol, 2-ethyl-1-hexanol, 2- (2-butoxyethoxy) ethanol, n-pentyl alcohol, s-pentyl alcohol, t-pentyl alcohol, isopentyl alcohol, isobutano (Also referred to as isobutyl alcohol or 2-methyl-1-propanol), isopropyl alcohol, 2-ethylbutanol, neopentyl alcohol, n-butanol, s-butanol, t-butanol, 1-propanol, 2-methyl-1 -Butanol, 2-methyl-2-butanol, 4-methyl-2-pentanol and the like.
In addition, as those having a cyclic structure, cyclopentanemethanol, 1-cyclopentylethanol, cyclohexanol, cyclohexanemethanol (CM), cyclohexaneethanol, 1,2,3,6-tetrahydrobenzyl alcohol, exo-norbornol, 2-methyl Examples include cyclohexanol, cycloheptanol, 3,5-dimethylcyclohexanol, and benzyl alcohol.
Among them, examples of the alcohol organic solvent include propylene glycol monomethyl ether (PGME), ethyl lactate (EL), 1-butoxy-2-propanol (BP), isobutanol (2-methyl-1-propanol), or 4- Methyl-2-pentanol is preferred. That is, as R ² , —CH (CH ₃ ) CH ₂ —O—CH ₃ , —CH (CH ₃ ) C (═O) O—CH ₂ —CH ₃ , —CH (CH ₃ ) CH ₂ —O [—CH ₂ —] ₃ CH ₃ , —CH ₂ —CH (CH ₃ ) CH ₃ , or —CH (CH ₃ ) CH ₂ —CH (CH ₃ ) CH ₃ is preferable.

  In the present invention, when R and X in formula (c0-1) do not have a fluorine atom, the structural unit (c0-1) needs to be copolymerized with another structural unit having a fluorine atom. Examples of the other structural unit having a fluorine atom include a structural unit (c0-2) having a fluorine atom, a structural unit (c2) described later, and the like.

Wherein (C0-2), R, ^{R 2} are each similar R in formula (C0-1) as described above, and ^{R 2.}
In formula (c0-2), A _aryl is an aromatic cyclic group which may have a substituent. Specific examples of A _aryl include a group in which two hydrogen atoms have been removed from an aromatic hydrocarbon ring which may have a substituent.
The ring skeleton of the aromatic cyclic group in A _aryl preferably has 6 to 15 carbon atoms, and examples thereof include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. Among these, a benzene ring or a naphthalene ring is particularly preferable.
In A _aryl , examples of the substituent that the aromatic cyclic group may have include a halogen atom, an alkyl group, an alkoxy group, a halogenated alkyl group having 1 to 5 carbon atoms, and an oxygen atom (═O). Can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. The substituent that the aromatic cyclic group of A _aryl may have is preferably a fluorine atom.
The aromatic cyclic group of A _aryl may have no substituent, may have a substituent, and preferably has no substituent.
In A _aryl , when the aromatic cyclic group has a substituent, the number of substituents may be one, two or more, and one or two. Is preferable, and one is more preferable.

In formula (c0-2), X ₀₁ represents a divalent linking group which may have a single bond or a fluorine atom. Examples of the divalent linking group that may have a fluorine atom include an alkylene group having 1 to 10 carbon atoms, —O—, —C (═O) —, —C (═O) —O—, and a carbonate bond. (—O—C (═O) —O—), —NH—C (═O) —, or a combination thereof may be mentioned, and the combination of —O— and an alkylene group having 1 to 12 carbon atoms is the most. preferable.
Examples of the alkylene group having 1 to 12 carbon atoms include linear, branched or cyclic alkylene groups, linear or branched alkylene groups having 1 to 5 carbon atoms, and 4 to 12 carbon atoms. A cyclic alkylene group is preferred.

In the present invention, when R, A _aryl , or X ₀₁ in formula (c0-2) does not have a fluorine atom, the structural unit (c0-2) is copolymerized with another structural unit having a fluorine atom. Is required. Examples of the other structural unit having a fluorine atom include a structural unit (c0-1) having a fluorine atom, a structural unit (c2) described later, and the like.

  Preferred examples of the structural unit (c0) include structural units represented by general formulas (c0-11) to (c0-15) and (c0-21) to (c0-24) shown below.

In general formulas (c0-11) to (c0-15) and (c0-21) to (c0-24) below, R and R ² are the same as defined above; R ⁵¹ and R ⁵² are each Independently represents 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, and a plurality of R ⁵¹ or R ⁵² may be the same or different; A1, a2, a5, a7, a9 and a11 to a13 each independently represent an integer of 1 to 5; a4, a6, a8 and a10 each independently represents an integer of 0 or 1 to 5; ; b1-b5 are each independently an integer of 0 or 1; ^{R 5} is a substituent, e represents an integer of 0 to 2; _{a 1} is a cyclic alkylene group having 4 to 20 carbon atoms .

In the general formula (c0-11), examples of the halogen atom for R ⁵¹ and R ⁵² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. The alkyl group of 1 to 5 carbon atoms for R ^51, R ^52, the same alkyl group of 1 to 5 carbon atoms in the R, and a methyl group or an ethyl group is preferred. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms of R ⁵¹ and R ⁵² include a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. Can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In the present invention, as R ⁵¹ and R ⁵² , a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group is preferable.
In general formula (c0-11), a1 is preferably 1 to 3, and more preferably 1 or 2.

In general formula (c0-12), a2 and a3 are each independently preferably 1 to 3, and more preferably 1 or 2. b1 is 0 or 1.
In the general formula (c0-13), a4 is preferably 0 or 1 to 3, more preferably 0 or 1 to 2, and most preferably 0 or 1. a5 is preferably 1 to 3, and more preferably 1 or 2. Examples of the substituent for R ⁵ include a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and an oxygen atom (═O). Can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. e is preferably 0 or 1, and particularly preferably 0 from an industrial viewpoint. b2 is preferably 0.
In the general formula (c0-14), a6 is preferably 0 or 1 to 3, more preferably 0 or 1 to 2, and most preferably 0 or 1. a7 is preferably 1 to 3, and more preferably 1 or 2. b3 is preferably 0. R ⁵ and e are the same as defined above.
In the general formula (c0-15), A ₁ is a cyclic alkylene group having 4 to 20 carbon atoms, preferably a cyclic alkylene group having 5 to 15 carbon atoms, and a cyclic alkylene group having 6 to 12 carbon atoms. More preferred. Specific examples include those exemplified for the “cyclic aliphatic hydrocarbon group” in the hydrocarbon group which may have a substituent described above.
In the general formula (c0-21), a8 is preferably 0 or 1 to 3, more preferably 0 or 1 to 2, and most preferably 0 or 1. a9 is preferably 1 to 3, and more preferably 1 or 2. b4 is preferably 0. R ⁵ and e are the same as defined above.
In general formula (c0-22), a10 is preferably 0 or 1 to 3, more preferably 0 or 1 to 2, and most preferably 0 or 1. a11 is preferably 1 to 3, and more preferably 1 or 2. b5 is preferably 0. R ⁵ and e are the same as defined above.
In general formula (c0-23), a12 is preferably 1 to 3, and more preferably 1 or 2. R ⁵ and e are the same as defined above.
In the general formula (c0-24), a13 is preferably 1 to 3, and more preferably 1 or 2. R ⁵ and e are the same as defined above.

  Specific examples of the structural unit (c0-1) represented by the formulas (c0-11) to (c0-15) are shown below. In the following formulas, R is the same as described above.

  Specific examples of the structural unit (c0-2) represented by the formulas (c0-21) to (c0-24) are shown below. In the following formulas, R is the same as described above.

  The structural unit (c0) is at least one selected from the group consisting of structural units represented by the general formulas (c0-11) to (c0-15) and (c0-21) to (c0-24). And at least one selected from the group consisting of structural units represented by the general formulas (c0-11) to (c0-15), (c0-21), and (c0-22) is more preferable. Particularly preferred is at least one selected from the group consisting of structural units represented by general formulas (c0-11), (c0-15) and (c0-22).

In the component (C), as the structural unit (c0), one type may be used alone, or two or more types may be used in combination.
In the component (C), the proportion of the structural units (c0-1) and (c0-2) is preferably 30 mol% or more, more preferably 50 mol%, based on the total of all the structural units constituting the component (C). Preferably, it may be 100 mol%. The effect of this invention improves more as the ratio of structural unit (c0-1) and (c0-2) is more than the lower limit of the said range.

The component (C) may have structural units other than the structural units (c0-1) and (c0-2) as long as the effects of the present invention are not impaired. In addition, as described above, when the structural unit (c0-1) or (c0-2) does not have a fluorine atom in its structure, the structural unit (c0) can be shared with other structural units having a fluorine atom. Polymerization is essential.
Such a structural unit is not particularly limited, but a structural unit derived from a compound copolymerizable with the compound deriving the structural unit (c0-1) or (c0-2) is preferable. As such a structural unit, for example, the structural units (a1) to (a4) listed as the constituents that the resin component (A1) may have, a structural unit derived from hydroxystyrene, or derived from styrene. Examples thereof include a structural unit and a structural unit having a carboxy group.
Among these, the structural units other than the structural units (c0-1) and (c0-2) of the fluorine-containing polymer compound do not correspond to the structural units (c0-1) and (c0-2). A structural unit having a fluorine atom (hereinafter referred to as “structural unit (c2)”) is preferable.

(Structural unit (c2))
In the fluorine-containing polymer compound (C), the structural unit (c2) is a structural unit having a fluorine atom that does not correspond to the structural units (c0-1) and (c0-2).
As the fluorine-containing polymer compound (C), the structural unit (c2) is preferably a structural unit represented by the following general formula (c2-1).

［式（ｃ２−１）中、Ｒは水素原子、炭素数１〜５の低級アルキル基、または炭素数１〜５のハロゲン化アルキル基であり；Ｑ^０は単結合又は２価の連結基であり、Ｒ^０はフッ素原子を有していてもよい有機基であり、Ｒ^０がフッ素原子を有しない場合は、Ｑ^０がフッ素原子を有する。］

[In formula (c2-1), R is a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Q ⁰ is a single bond or a divalent linking group; Yes, R ⁰ is an organic group which may have a fluorine atom, and when R ⁰ does not have a fluorine atom, Q ⁰ has a fluorine atom. ]

In said formula (c2-1), R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group, and a hydrogen atom or a methyl group is preferable.
In Formula (c2-1), Q ⁰ is a single bond or a divalent linking group.
Preferred examples of the divalent linking group for Q ⁰ include a hydrocarbon group which may have a substituent and a group containing a hetero atom. The divalent linking group for Q ⁰ is preferably a divalent organic group having no acid dissociable portion. Examples of the hydrocarbon group optionally having a substituent and a group containing a hetero atom include the same hydrocarbon groups optionally having the substituent of X and the same group containing a hetero atom. Among them, Q ⁰ is more preferably a single bond or a group containing a hetero atom, and a single bond or a combination of the “one or more of these groups” and the aliphatic hydrocarbon group is particularly preferable.

In the general formula (c2-1), R ⁰ is an organic group that may have a fluorine atom. However, when R ⁰ does not have a fluorine atom, Q ⁰ has a fluorine atom.
Here, the “organic group having a fluorine atom” refers to a group in which part or all of the hydrogen atoms in the organic group are substituted with fluorine atoms.
Preferred examples of the organic group optionally having a fluorine atom for R ⁰ include a hydrocarbon group optionally having a fluorine atom.
The hydrocarbon group which may have a fluorine atom may be linear, branched or cyclic.
R ⁰ preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms.
Further, in the organic group having a fluorine atom of R ⁰ , 25% or more of hydrogen atoms in the organic group are preferably fluorinated, more preferably 50% or more are fluorinated, and 60% or more. It is particularly preferable that is fluorinated since the hydrophobicity of the resist film during immersion exposure is increased.
R ⁰ is preferably a group other than an acid dissociable group, a base dissociable group, an acid dissociable group, and a base dissociable group.
The acid dissociable group is a group that dissociates with an acid and increases the solubility in an alkali developer. When the acid dissociable group does not contain a fluorine atom, Q ⁰ has a fluorine atom.
The basic decomposable group is a group that exhibits decomposability by the action of an alkali developer (—O—R ⁰ is dissociated). “Degradable with respect to alkali developer” means that it is decomposed by the action of an alkali developer (preferably at 23 ° C. by the action of a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution. This means that the solubility in an alkaline developer is increased. This is because the ester bond [—C (═O) —O—R ⁰ ] is decomposed (hydrolyzed) by the action of a base (alkaline developer) to produce a hydrophilic group [—C (═O) —OH]. (—O—R ⁰ dissociates).

Preferred examples of the base dissociable group include a fluorinated hydrocarbon group that may or may not have a substituent. Of these, a fluorinated saturated hydrocarbon group or a fluorinated unsaturated hydrocarbon group is preferable, and a fluorinated saturated hydrocarbon group is particularly preferable.
R ⁰ may be linear, branched or cyclic, and is preferably linear or branched.
In R ⁰ , the carbon number is preferably 1-20, more preferably 1-15, particularly preferably 1-10, and most preferably 1-5.
Further, in the organic group having a fluorine atom of R ⁰ , 25% or more of hydrogen atoms in the organic group are preferably fluorinated, more preferably 50% or more are fluorinated, and 60% or more. It is particularly preferable that is fluorinated since the hydrophobicity of the resist film during immersion exposure is increased.

The group other than the acid dissociable group and the base dissociable group is, for example, a linear, branched or cyclic alkyl group having 3 to 15 carbon atoms (however, a group having a tertiary carbon atom is excluded). In this case, Q ⁰ has a fluorine atom.

(Acid dissociable group)
The acid dissociable group for R ⁰ is not particularly limited as long as it is an organic group that can be dissociated by the action of an acid, and is a cyclic or chain tertiary alkyl ester type acid dissociable group; an alkoxyalkyl group And acetal type acid dissociable groups. Among these, R ⁰ is preferably a tertiary alkyl ester type acid dissociable group, and more preferably a structural unit represented by the following general formula (IV-1).

［式（ＩＶ−１）中、複数のＲ^２０１はそれぞれ同じであっても異なっていてもよく、少なくとも１つは炭素数１〜４の直鎖状もしくは分岐鎖状のアルキル基であり；残りの２つのＲ^２０１は、それぞれ独立して炭素数１〜４の直鎖状もしくは分岐鎖状のアルキル基、または炭素数４〜２０の１価の脂肪族環式基であるか、あるいは、前記残りの２つのＲ^２０１は相互に結合して、それぞれが結合している炭素原子と共に炭素数４〜２０の２価の脂肪族環式基を形成している。］

[In the formula (IV-1), a plurality of R ²⁰¹ may be the same or different, and at least one is a linear or branched alkyl group having 1 to 4 carbon atoms; two of R ²⁰¹ of are either each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or a monovalent aliphatic cyclic group having 4 to 20 carbon atoms, or wherein The remaining two R ²⁰¹ are bonded to each other to form a divalent aliphatic cyclic group having 4 to 20 carbon atoms together with the carbon atom to which each of R ²⁰¹ is bonded. ]

In the general formula (IV-1), examples of the aliphatic cyclic group represented by R ²⁰¹ include one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Excluded groups and the like. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. More specifically, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like can be given.
Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group.

As the acid dissociable group represented by the general formula (IV-1), a plurality of R ²⁰¹ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms. Examples thereof include a butyl group, a tert-pentyl group, and a tert-hexyl group.

As the acid dissociable group represented by the general formula (IV-1), at least one of the plurality of R ^{201 is} a linear or branched alkyl group having 1 to 4 carbon atoms, and the remaining two R ²⁰¹ Are each independently a linear or branched alkyl group having 1 to 4 carbon atoms or a monovalent aliphatic cyclic group having 4 to 20 carbon atoms, such as 1- (1-adamantyl) ) -1-methylethyl group, 1- (1-adamantyl) -1-methylpropyl group, 1- (1-adamantyl) -1-methylbutyl group, 1- (1-adamantyl) -1-methylpentyl group; 1 -(1-cyclopentyl) -1-methylethyl group, 1- (1-cyclopentyl) -1-methylpropyl group, 1- (1-cyclopentyl) -1-methylbutyl group, 1- (1-cyclopentyl) -1- Methylpentyl 1- (1-cyclohexyl) -1-methylethyl group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl)- 1-methylpentyl group, etc. are mentioned.

As the acid dissociable group represented by formula (IV-1), among the plurality of ^{R 201,} 1 single ^{R 201} is a straight-chain or branched alkyl group having 1 to 4 carbon atoms, the two Examples of the group in which R ²⁰¹ is bonded to each other to form a divalent aliphatic cyclic group having 4 to 20 carbon atoms together with the carbon atom to which each is bonded include a 2-methyl-2-adamantyl group, 2-alkyl-2-adamantyl group such as 2-ethyl-2-adamantyl group, 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-methyl-1-cyclohexyl group, 1-ethyl 1-alkyl-1-cycloalkyl groups such as a -1-cyclohexyl group.
Among these, as the acid dissociable group represented by the general formula (IV-1), among the plurality of R ²⁰¹ , one R ²⁰¹ is a linear or branched alkyl group having 1 to 4 carbon atoms. In which two R ²⁰¹ 's are bonded to each other to form a divalent aliphatic cyclic group having 4 to 20 carbon atoms together with the carbon atoms to which they are bonded, particularly 2-methyl A 2-adamantyl group is preferred.

Moreover, as long as the group represented by general formula (IV-1) can function as an acid dissociable group, each R ²⁰¹ may have a substituent. Examples of the substituent include a halogen atom such as a fluorine atom.

Below, the suitable specific example of a structural unit (c2) is illustrated.
Hereinafter, the case where R ⁰ in the general formula (c2-1) is a “base dissociable group” is referred to as a structural unit (c21), and the case where R ² is an “acid dissociable group” is represented by a structural unit (c22). That's it.

(Structural unit (c21))
Preferable specific examples of the structural unit (c21) include structural units that do not correspond to the structural unit (c0) and are represented by the following general formula (c21-1) or formula (c21-2).

［式中、Ｒはそれぞれ独立して水素原子、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り；Ｘは二価の有機基であり、Ａ_ａｒｙｌは置換基を有していてもよい芳香族環式基であり、Ｘ_０１は単結合又は二価の連結基であり；Ｒ^２１は、それぞれ独立して、塩基解離性基である。ただし、Ｒ^２１がフッ素原子を有さない場合、（ｃ２１−１）においてはＸが、（ｃ２１−２）においてはＡ_ａｒｙｌ、またはＸ_０１がフッ素原子を有するものとする。］

[Wherein, R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X is a divalent organic group, and A _aryl is substituted. An aromatic cyclic group which may have a group, X ₀₁ is a single bond or a divalent linking group; and each R ²¹ is independently a base-dissociable group. ^{However, if R 21} has no fluorine atom, X is in the (c21-1), assumed to have the _{A aryl} or _{X 01} is a fluorine atom, in (c21-2). ]

In the general formula (c21-1) or _{(c21-2), R, A aryl} , X, and _{X 01} are each, the formula (c-1-1) as in ~ (c-1-2) R, A _aryl , X, and X _{01 are the} same.
The base dissociable group for R ²¹ is the same as described above, more preferably an alkyl group having 1 to 2 carbon atoms or a fluorinated hydrocarbon group having 1 to 5 carbon atoms, a methyl group, —CH ₂ —CF _{3. , -CH 2 -CF 2 -CF 3,} -CH (CF 3) 2, and most preferably _{-CH 2 -CH 2 -CF 2 -CF 2} -CF 2 -CF 3. When R ²¹ is a methyl group, an ethyl group, or a fluorinated hydrocarbon group, —O—R ²¹ in the formula becomes a base dissociable group that is dissociated by the action of an alkali developer.

  Preferred examples of the structural unit (c21) include those represented by the following general formulas (c21-1-1) to (c21-1-5) or (c21-2-1) to (c21-2-4). The structural unit is given.

In the general formulas (c21-1-1) to (c21-1-5) or (c21-2-1) to (c21-2-4), R, R ⁵¹ , R ⁵² , a1 to a13, b1 to ^{b5, R} 5, e and _{a 1} are both, ^R in description in the above-mentioned structural unit ^{(c0), R 51, R} 52, a1~a13, b1~b5, same as ^R 5, e and _{a 1} And R ²¹ is the same as defined above.

  Specific examples of the structural units represented by general formulas (c21-1-1) to (c21-1-5) and general formulas (c21-2-1) to (c21-2-4) are shown below. .

  The structural unit (c21) is composed of structural units represented by the general formulas (c21-1-1) to (c21-1-5) and (c21-2-1) to (c21-2-4). Preferably, at least one selected from the group is represented by the general formulas (c21-1-1) to (c21-1-5), (c21-2-1) and (c21-2-2) At least one selected from the group consisting of units is more preferred, and a group consisting of structural units represented by the general formulas (c21-1-1), (c21-1-5) and (c21-2-2) At least one selected from is particularly preferred.

As the structural unit (c21), one type may be used alone, or two or more types may be used in combination.
In the case where the component (C21) is contained in the component (C), the proportion of the component (c21) is preferably 10 to 90 mol% with respect to the total of all the components constituting the component (C). 20-90 mol% is more preferable, and 30-90 mol% is especially preferable. When the proportion of the structural unit (c21) is not less than the lower limit of the above range, the characteristics that become hydrophobic during immersion exposure are further improved in the formation of the resist pattern. If it is less than or equal to the upper limit of the range, it is possible to balance with other structural units.

(Structural unit (c22))
Preferable specific examples of the structural unit (c22) include structural units represented by general formula (c22-1) shown below.

［式（ｃ２２−１）中、Ｒはそれぞれ独立して水素原子、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り；Ｑ^０’は単結合又は二価の連結基であり、Ｒ^２２は酸解離性基である。］

[In formula (c22-1), each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Q ⁰ ′ is a single bond or a divalent group. R ²² is an acid dissociable group. ]

In general formula (c22-1), R is the same as defined above, and more preferably a hydrogen atom or a methyl group.
Examples of the acid dissociable group for R ²² include the same groups as those exemplified above in the description of the acid dissociable group for R ² .

In the general formula (c22-1), examples of the structural unit in which Q ⁰ ′ is a single bond include structural units represented by the following general formulas (c22-1-1) to (c22-1-4). It is mentioned as a suitable thing.
In the general formula (c22-1), when Q ⁰ ′ is a divalent linking group, the divalent linking group is the same as X _{01 in the} formula (c21-2) or a divalent fragrance. Group hydrocarbon groups. As a bivalent aromatic hydrocarbon group, a C6-C20 aromatic hydrocarbon group is mentioned, The group remove | excluding two hydrogen atoms from benzene, naphthalene, and anthracene is mentioned.
In the structural unit (c22), as Q ⁰ ′, a single bond or —C (═O) —O—R ^c — [R ^c is a straight chain having 1 to 10 carbon atoms which may contain an oxygen atom or It is a branched alkylene group. The alkylene group may be fluorinated. It is preferable that it is a single bond.
In the general formula (c22-1), examples of the structural unit in which Q ⁰ ′ is —C (═O) —O—R ^c — include, for example, the following general formulas (c22-1-5) to (c22-1) The structural unit represented by -11) is preferable.
However, R in the following general formula is the same as the above R, and is preferably a hydrogen atom or a methyl group.

  The structural unit (c22) is preferably at least one selected from the group consisting of structural units represented by the general formulas (c22-1-1) to (c22-1-11). -1-1) to (c22-1-8), at least one selected from the group consisting of structural units represented by formulas (c22-1-1) to (c22-1-4) is more preferable. The structural unit represented by the formula is particularly preferred.

In the component (C), as the structural unit (c22), one type may be used alone, or two or more types may be used in combination.
When the component (C22) is contained in the component (C), the proportion of the component (c22) is preferably 10 to 80 mol% with respect to the total of all the components constituting the component (C). 15-75 mol% is more preferable, and 20-70 mol% is especially preferable. When the proportion of the structural unit (c22) is not less than the lower limit of the above range, in the formation of the resist pattern, the property of becoming hydrophobic during immersion exposure is further improved. Further, the lithography characteristics are further improved. If it is less than or equal to the upper limit of the range, it is possible to balance with other structural units.

In the component (C), as the structural unit (c2), one type may be used alone, or two or more types may be used in combination.
In the case where the component (C2) is contained in the component (C), the proportion of the component (c2) is preferably 5 to 80 mol% with respect to the total of all the components constituting the component (C). 10-60 mol% is more preferable, 15-50 mol% is further more preferable, and 20-40 mol% is especially preferable. When the proportion of the structural unit (c2) is not less than the lower limit of the above range, in the formation of the resist pattern, the characteristics that it is hydrophobic during immersion exposure and the hydrophilicity increases when exposure and PEB are performed are more remarkable. become. In addition, the bridge defect can be suppressed in the line and space pattern, and the defective opening defect can be suppressed in the contact hole pattern. Further, the proportion of hydrocarbon groups is improved, and the scan followability is improved. When the amount is not more than the upper limit, the balance with the structural unit (c0) becomes good, and the water repellency effect is improved.

[Other structural units]
The component (C) is a structural unit other than the structural units (c0-1), (c0-2), and the structural unit (c2) (hereinafter referred to as “structural unit (c3)”, as long as the effects of the present invention are not impaired. .) May be included.
The structural unit (c3) is not particularly limited as long as it is a structural unit derived from a compound copolymerizable with the compound that derives the structural units (c0-1), (c0-2), and (c2). As such a structural unit, what has been proposed as a structural unit of a base resin for a chemically amplified resist (for example, among the structural units (a1) to (a4), the structural unit (c0-1), (C0-2) and those not corresponding to (c2)).

In the component (C), as the structural unit (c3), one type may be used alone, or two or more types may be used in combination.
When the component (C3) is contained in the component (C), the proportion of the component (c3) is preferably 1 to 25 mol% based on the total of all the components constituting the component (C). 5-20 mol% is more preferable, and 10-20 mol% is especially preferable.

  In the present invention, the component (C) is a polymer containing the structural unit (c0-1) or the structural unit (c0-2), and the polymer is composed of only one structural unit (c0-1). Polymer (homopolymer) consisting of only one structural unit (c0-2); copolymer consisting of two or more structural units (c0-1); two or more structural units A copolymer consisting of the unit (c0-2); a copolymer consisting of the structural units (c0-1) and (c0-2); a polymer consisting of the structural units (c0-1) and (c2), etc. are suitable. It is mentioned as a thing.

The mass average molecular weight (Mw) of the component (C) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000, and 4000 to 25000. Most preferred. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 4.0, and most preferably 1.2 to 3.0. Mn represents a number average molecular weight.

  The component (C) described above can be suitably used as an additive for a resist composition for immersion exposure.

In the resist composition of the present invention, as the component (C), one type may be used alone, or two or more types may be used in combination.
The content of the component (C) in the resist composition of the present invention is preferably 0.1 to 50 parts by mass, more preferably 0.1 to 40 parts by mass, with respect to 100 parts by mass of the component (A). -30 mass parts is especially preferable, and 0.5-15 mass parts is the most preferable.
The hydrophobicity of the resist film formed using the resist composition is improved by setting it to the lower limit of the above range, and the hydrophobicity suitable for immersion exposure is obtained. The hydrophilicity of the resist film by contact becomes higher. When it is at most the upper limit value, the lithography properties are improved.

<Optional component / (D) component>
The positive resist composition of the present invention may further contain a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) as an optional component.
The component (D) is not particularly limited as long as it acts as an acid diffusion controller, that is, a quencher that traps the acid generated from the component (B) by exposure, and a wide variety of components have already been proposed. Therefore, any known one may be used, and aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are particularly preferable. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 20 carbon atoms.
Examples of the aliphatic amine include an amine (alkylamine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 20 or less carbon atoms. .
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, 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-hexylamine, tri-n-pentylamine , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol amine, tri -n- octanol amine, stearyl diethanolamine, alkyl alcohol amines such as lauryl diethanolamine. Among these, trialkylamine and / or alkyl alcohol amine are preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. 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.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. 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.
Examples of the aromatic amine include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, and tribenzylamine.
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-hydroxy Ethoxy) ethoxy} ethylamine and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

<Optional component (E) component>
The resist composition of the present invention comprises, as optional components, an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, and the like. At least one compound (E) selected from the group (hereinafter referred to as component (E)) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids and derivatives thereof include phosphoric acid, phosphonic acid, phosphinic acid and the like, and among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
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 the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
As the component (E), an organic carboxylic acid is preferable, and salicylic acid is particularly preferable.
(E) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

  If desired, the positive resist composition of the present invention further has miscible additives other than those described above, for example, an additional resin for improving the performance of the resist film, a surfactant for improving the coating property, A dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

<(S) component>
The positive resist composition of the present invention is produced by dissolving a material in an organic solvent.
In the present invention, the component (S) contains an alcohol-based organic solvent represented by the following general formula (s-0) (hereinafter, the alcohol-based organic solvent is referred to as “component (S1)”).

［式中、Ｒ^２は、炭素数１〜１０の炭化水素基であって、該炭化水素基の水素原子が水酸基で置換されていてもよく、該炭化水素基のＣＨ_２がカルボニル基または酸素原子で置換されていてもよい。］

[Wherein R ² is a hydrocarbon group having 1 to 10 carbon atoms, the hydrogen atom of the hydrocarbon group may be substituted with a hydroxyl group, and CH ₂ of the hydrocarbon group is a carbonyl group or oxygen It may be substituted with an atom. ]

[(S1) component]
The component (S1) is an alcohol solvent, and an alcohol solvent that is usually used in a resist composition can be used.
Examples of the alcohol solvent include those similar to the alcohol solvents described in R ² above. Among them, propylene glycol monomethyl ether (PGME), ethyl lactate (EL), 1-butoxy-2-propanol (BP ), Isobutanol (2-methyl-1-propanol), or 4-methyl-2-pentanol.

As the component (S1), one type may be used alone, or two or more types may be used.
The content of the component (S1) is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, and 100% by mass in the component (S). It may be. By being more than the lower limit of the range, the storage stability of the resist composition of the present invention is improved. In addition, the resist composition of the present invention has a hydrophobicity before development and can stably obtain the effect of increasing hydrophilicity after development.

  The component (S) can be used in combination with an organic solvent other than the component (S1) (hereinafter referred to as “component (S2)”) in addition to the component (S1) within a range that does not impair the effects of the present invention. .

[(S2) component]
As the component (S2), any component can be used as long as it can dissolve each component to be used to form a uniform solution, and any one of conventionally known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone;
Ketones such as acetone, methyl ethyl ketone, cycloheptanone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone;
A compound having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate;
Derivatives of polyhydric alcohols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, etc., or compounds having an ether bond such as monophenyl ether [among these, Propylene glycol monomethyl ether acetate (PGMEA) is preferred];
Esters such as methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate;
Aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. be able to.
Aromatic organic solvents such as ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene,
Examples thereof include dimethyl sulfoxide (DMSO).
These (S2) components may be used independently and may use 2 or more types.

In the resist composition of the present invention, it is preferable to use a mixed solvent of the (S1) component and the (S2) component as the (S) component. By using such a mixed solvent, it is possible to obtain the hydrophobicity before development and the increase in hydrophilicity after development, which are the effects of the present invention, while maintaining good solubility of the component (A).
The mixing ratio of the component (S1) and the component (S2) is preferably (S1) / (S2) = 10/90 to 90/10, and preferably 20/80 to 80/20 in terms of mass ratio. More preferred. When the ratio of the component (S1) to the component (S2) is within the above range, the above effect can be further obtained while maintaining the solubility of the resist material.
Among them, it is particularly preferable to use propylene glycol monomethyl ether acetate (PGMEA) as the component (S2) and propylene glycol monomethyl ether (PGME) or ethyl lactate (EL) as the component (S1).
More specifically, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3. . Moreover, as (S) component, the mixed solvent of these and (gamma) -butyrolactone is also preferable.

  The amount of the component (S) used as a whole is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is It is used in a range of 1 to 20% by mass, preferably 2 to 15% by mass.

The resist composition of the present invention has a component (C) containing the structural unit (c0-1) or (c0-2). Since the component (C) has a fluorine atom, the component (C) has high hydrophobic properties and has -C (= O) -O-R ² to increase hydrophilicity under basic conditions. Has properties. This is because the ester bond [—C (═O) —O—] is decomposed (hydrolyzed) by the action of a base (alkaline developer) to produce a hydrophilic group [—C (═O) —OH]. It is. Therefore, the resist film formed using the resist composition of the present invention in which the component (C) is blended with the component (A) and the component (B) has high hydrophobicity before coming into contact with the alkali developer. On the other hand, hydrophilicity is increased by contact with an alkaline developer.
As described above, since the resist composition of the present invention has high hydrophobicity at the time of immersion exposure, when the resist composition of the present invention is used as a resist composition for immersion exposure, a scanning immersion exposure apparatus is used. It is excellent in water followability required when immersion exposure is performed.
Moreover, since hydrophilicity increases after alkali development, when the resist composition of the present invention is used as a resist composition for immersion exposure, defects during immersion exposure can be effectively reduced. That is, in the immersion exposure, when immersion exposure is performed on the resist film, the solubility of the exposed portion in the alkaline developer changes. For example, in the case of the positive type, the solubility of the exposed portion in the alkaline developer increases, and in the case of the negative type, the solubility of the exposed portion in the alkaline developer decreases. Then, by performing alkali development, in the case of the positive type, the exposed portion is removed, and in the case of the negative type, the unexposed portion is removed to form a resist pattern.
At this time, the surface of the resist film where the radiation is not irradiated by immersion exposure (for example, the unexposed portion in the case of a positive type) is subjected to a defect (watermark defect) after the alkali development and the influence of an immersion medium such as water. However, since the hydrophilicity of a resist film formed using the resist composition of the present invention increases during alkali development, the occurrence of defects can be reduced.

Further, by using the resist composition of the present invention as a resist composition for immersion exposure, elution of substances from the resist film during immersion exposure can be suppressed.
That is, as described above, the immersion exposure is performed by exposing the portion between the lens and the resist film on the wafer, which is conventionally filled with an inert gas such as air or nitrogen, at a time higher than the refractive index of air. This is a method including a step of performing exposure (immersion exposure) in a state filled with a solvent (immersion medium) having a large refractive index. In the immersion exposure, when the resist film and the immersion solvent come into contact with each other, elution (substance elution) of substances (component (B), etc.) in the resist film into the immersion solvent occurs. Substance elution causes phenomena such as alteration of the resist layer and change in the refractive index of the immersion solvent, thereby deteriorating the lithography properties.
The amount of this substance elution is affected by the characteristics of the resist film surface (for example, hydrophilicity / hydrophobicity). Therefore, for example, it is presumed that elution of the substance is reduced by increasing the hydrophobicity of the resist film surface.
Since the resist film formed using the resist composition of the present invention contains the component (C), it has higher hydrophobicity before exposure and alkali development than when it does not contain the component (C). Therefore, when the resist composition of the present invention is used as a resist composition for immersion exposure, substance elution during immersion exposure can be suppressed. Since substance elution can be suppressed, by using the resist composition of the present invention, alteration of the resist film and change in the refractive index of the immersion solvent can be suppressed in immersion exposure. A resist pattern having a good shape and the like can be formed by suppressing fluctuations in the refractive index of the immersion solvent. Further, the contamination of the lens of the exposure apparatus can be reduced, and therefore, it is not necessary to take protective measures against these, and it is possible to contribute to the simplification of the process and the exposure apparatus.
In addition, since the resist film formed from the resist composition of the present invention hardly swells with water, a fine resist pattern can be formed with high accuracy.
Furthermore, the resist composition of the present invention has good lithography properties such as sensitivity, resolution, and etching resistance, and can form a resist pattern without any practical problems when used as a resist in immersion exposure. For example, by using the resist composition for use in the present invention, a fine resist pattern having a dimension of 100 nm or less can be formed.

The hydrophobicity of the resist film includes the contact angle with water, for example, the static contact angle (the angle between the surface of the water droplet on the resist film in the horizontal state and the resist film surface), and the dynamic contact angle (the tilted resist film). The contact angle when the water droplet starts to fall (fall angle), the contact angle (advance angle) at the front end point of the water drop direction, the contact angle (retreat angle) at the rear end point of the drop direction), etc. It can be evaluated by measuring. For example, the higher the hydrophobicity of the resist film, the larger the static contact angle, advancing angle, and receding angle, while the falling angle becomes smaller.
Here, as shown in FIG. 1, when the plane 2 on which the droplet 1 is placed is gradually inclined, the advance angle starts to move (drop) on the plane 2 when the droplet 1 is gradually inclined. Is the angle θ ₁ formed by the surface of the droplet at the lower end 1 a of the droplet 1 and the plane 2. At this time (when the droplet 1 starts moving (falling) on the plane 2), the angle θ2 formed by the droplet surface at the upper end 1b of the droplet 1 and the plane ₂ is the receding angle, The inclination angle θ _{3 of the} plane 2 is the falling angle.

Further, the resist composition of the present invention is a conventional resist composition containing a fluorine-containing polymer compound having an ester bond [—C (═O) —O—] in its structure (see Patent Documents 2 to 3). Etc.) and is superior in storage stability.
The reason why the above effect is obtained is not clear, but as a factor thereof, the structural unit (c0-1) or (c0-2) is a group common to the alcohol organic solvent represented by the formula (s-0). And having a certain R ² .
As will be described later as a compound production example, in the present invention, the fluorine-containing polymer compound (C) having the structural unit (c0-1) or (c0-2) is a compound after being decomposed with respect to an alkali developer. , Produced by condensation of a compound having a hydrophilic group [—C (═O) —OH] at the terminal with an alcohol-based organic solvent (s-0) represented by the formula (s-0), It has R ² which is the common group. From this, when the fluorine-containing polymer compound (C) having the structural unit (c0-1) or (c0-2) is dissolved in the alcohol organic solvent (s-0), a request for an equilibrium reaction is required. From the above, the hydrolysis reaction of the fluorine-containing polymer compound (C) is suppressed, and thus the above effect is considered to be obtained.
Furthermore, the fluorine-containing polymer compound (C) having the structural unit (c0-1) or (c0-2) having the structure as described above is also resistant to hydrolysis with a highly basic amine. It is possible to use a highly basic amine in the composition, and the degree of freedom in optimizing lithography properties is increased.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention includes a step of forming a resist film on a support using the resist composition of the present invention, a step of exposing the resist film, and developing the resist film to form a resist pattern. Forming.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the positive resist composition of the present invention is applied onto a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds under a temperature condition of 80 to 150 ° C., preferably For 60 to 90 seconds, using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus, exposure through a mask pattern, or drawing by direct irradiation of an electron beam without using a mask pattern, etc. Then, PEB (post-exposure heating) is applied for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Subsequently, this is developed using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH), preferably rinsed with pure water and dried. In some cases, a baking process (post-bake) may be performed after the development process.
In this way, a resist pattern faithful to the mask pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC).
The wavelength used for exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition is effective for KrF excimer laser, ArF excimer laser, EB or EUV, particularly ArF excimer laser.

The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure (Liquid Immersion Lithography).
In immersion exposure, the space between the resist film and the lens at the lowest position of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in that state. It is an exposure method.
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film to be exposed is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include 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 as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).
As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility, and the like.

≪Compound≫
The compound of the present invention is a compound represented by any one of the following general formulas (1) to (10) (hereinafter referred to as “compound (1) to compound (10)”, etc.), and the present invention described above. It is useful as a monomer for deriving the structural unit (c0-1) or (c0-2) in the resist composition of the first aspect, or a monomer for deriving the polymer compound of the fourth aspect described later.

［式中、Ｘはフッ素原子を有していてもよい２価の連結基であり、Ａ_ａｒｙｌは、置換基を有していてもよい芳香族環式基であり、Ｘ_０１は単結合またはフッ素原子を有していてもよい２価の連結基である。］

[Wherein, X is a divalent linking group optionally having a fluorine atom, A _aryl is an aromatic cyclic group optionally having a substituent, and X ₀₁ is a single bond or It is a divalent linking group which may have a fluorine atom. ]

In the formulas (1) to (10), X, A _aryl and X ₀₁ are the same as X, A _aryl and X ₀₁ in the component (C), respectively.

(Method for producing compound)
-Production Example of Compound (1) The production method of compound (1) is not particularly limited. For example, compound (1) is obtained by reacting the following compound (i-0) with PGME. It is done.

［式中、Ｘは前記と同じである。］

[Wherein X is the same as defined above. ]

The method of reacting compound (i-0) and PGME is not particularly limited. For example, compound (i-0) is added to a reaction solvent in which PGME is dissolved in the presence of an appropriate base, and the mixture is stirred. Then, the reaction mixture can be washed and recovered.
Compound (i-0) may be commercially available, or can be synthesized by a conventional method.
Examples of the base include inorganic bases such as sodium hydride, K ₂ CO ₃ and Cs ₂ CO ₃ ; organic bases such as triethylamine, 4-dimethylaminopyridine (DMAP) and pyridine. These may be used alone or in combination of two or more. The amount of the base used may be a catalytic amount, and is usually about 0.01 to 0.5 mol with respect to 1 mol of compound (i-0).
Any reaction solvent may be used as long as it can dissolve the starting compounds (i-0) and PGME. Specifically, tetrahydrofuran (THF), acetone, dimethylformamide (DMF), dimethylacetamide, dimethylsulfoxide (DMSO) ), Acetonitrile and the like.
The reaction time varies depending on the reactivity between the raw material compound (i-0) and PGME, the reaction temperature, and the like, but is usually preferably about 0.5 to 80 hours, more preferably 1 to 50 hours.
10-200 degreeC is preferable and, as for reaction temperature, 15-100 degreeC is more preferable.
0.5-5 mol is preferable with respect to 1 mol of compounds (i-0), and, as for the usage-amount of PGME in the said reaction, 0.8-4 mol is more preferable.

In the compounds (2) to (5), PGME is converted into ethyl lactate (EL), 1-butoxy-2-propanol (BP), isobutanol (2-methyl-1-propanol), or 4-methyl-2, respectively. -It can manufacture similarly to the manufacture example of the said compound (1) except replacing with pentanol.
In addition, compounds (6) to (10) are produced in the same manner as compounds (1) to (5), respectively, except that the following compound (i-1) is used instead of compound (i-0). be able to.

［式中、Ａ_ａｒｙｌ、Ｘ_０１は、それぞれ、前記と同じである。］

[Wherein A _aryl and X ₀₁ are the same as defined above. ]

≪Polymer compound≫
The polymer compound of the present invention is a polymer compound containing a structural unit represented by any one of the following general formulas (11) to (20).

［式中、Ｒはそれぞれ独立に、水素原子、炭素数１〜５のアルキル基、炭素数１〜５のハロゲン化アルキル基であり、Ｘはフッ素原子を有していてもよい２価の連結基であり、Ａ_ａｒｙｌは、置換基を有していてもよい芳香族環式基であり、Ｘ_０１は単結合またはフッ素原子を有していてもよい２価の連結基である。］

[Wherein, R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and X is a divalent linkage optionally having a fluorine atom. A _aryl is an aromatic cyclic group which may have a substituent, and X ₀₁ is a divalent linking group which may have a single bond or a fluorine atom. ]

In the formulas (11) to (20), R, X, A _aryl and X ₀₁ are the same as R, X, A _aryl and X _{01 in the} component (C), respectively.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
In this example, the unit represented by the chemical formula (1) is referred to as “compound (1)”, and the same applies to compounds represented by other formulas.

[Monomer Synthesis Example 1 (Synthesis of Compound 2c)]
Propylene glycol monomethyl ether (PGME) 11.47 g (127.2 mmol), ethyldiisopropylaminocarbodiimide (EDCI) hydrochloride 35.68 g (190.8 mmol), dimethylaminopyridine (DMAP) 0.77 g at 0 ° C. in a nitrogen atmosphere. The following compound 1c (16.67 g, 115.7 mmol) was added to a THF solution (300 ml) of (6.3 mmol), and the mixture was returned to room temperature and stirred for 3 hours. After confirming the disappearance of the raw materials by thin layer chromatography (TLC), the reaction solution was cooled to 0 ° C., and water was added to stop the reaction.
The solvent was distilled off under reduced pressure, and the organic layer obtained by extraction three times with ethyl acetate was washed twice with water. The solvent was distilled off under reduced pressure to obtain 25 g of Compound 2c as a colorless liquid.

About the obtained compound 2c, < ¹ > H-NMR was measured. The results are shown below.
¹ H-NMR (CDCl ₃ ) 6.17 (s, 1H, Hb), 5.61 (s, 1H, Hb), 5.12-5.10 (m, 1H, He), 4.77-4 .65 (s, 2H, Hc), 3.43-3.32 (m, 5H, Hf + Hg), 1.94 (s, 3H, Ha), 1.24-1.22 (m, 3H, Hd) .
From the results shown above, it was confirmed that the compound 2c had a structure shown below.

[Monomer Synthesis Example 2 (Synthesis of Compound 4c)]
Under a nitrogen atmosphere at 0 ° C., 5.0 g (55.5 mmol) of propylene glycol monomethyl ether (PGME), 15.95 g (83.2 mmol) of ethyldiisopropylaminocarbodiimide (EDCI) hydrochloride, 0.34 g of dimethylaminopyridine (DMAP) To 150 ml of a THF solution of (2.8 mmol), 11.20 g (83.2 mmol) of the compound 3c was added, returned to room temperature, and stirred for 3 hours. After confirming the disappearance of the raw materials by thin layer chromatography (TLC), the reaction solution was cooled to 0 ° C., and water was added to stop the reaction.
The solvent was distilled off under reduced pressure, and the organic layer obtained by extraction three times with ethyl acetate was washed twice with water. The solvent was distilled off under reduced pressure to obtain 5 g of Compound 4c as a colorless liquid.

About the obtained compound 4c, < ¹ > H-NMR was measured. The results are shown below.
¹ H-NMR (CDCl ₃ ) 6.13 (s, 1H, Hb), 5.60 (s, 1H, Hb), 5.36-5.26 (m, 1H, Hc), 5.17-5 .15 (m, 1H, Hg),
3.44-3.37 (m, 2H, Hh), 3.31-3.29 (d, 3H, He), 1.91 (s, 3H, Ha), 1.85-1.73 (m , 2H, Hd), 1.25-1.21 (m, 3H, Hi), 0.95-0.93 (m, 3H, Hf).
From the results shown above, it was confirmed that the compound 4c had a structure shown below.

[Polymer Synthesis Example 1 (Synthesis of Polymer Compound 1c)]
In a three-necked flask connected with a thermometer and a reflux tube, 3.00 g (13.89 mmol) of Compound 2c, 2.46 g (9.26 mmol) of Compound 5c were added and dissolved in 12.74 g of tetrahydrofuran. To this solution, 0.533 g of dimethyl azobisisobutyrate (V-601) was added as a polymerization initiator and dissolved. This reaction solution was subjected to a polymerization reaction at 80 ° C. for 5 hours in a nitrogen atmosphere, and then cooled to room temperature. The obtained reaction polymerization solution was dropped into a large amount of n-heptane, and an operation for precipitating the polymer was performed.
The precipitated white powder was filtered off, washed and dried to obtain 4 g of the target polymer compound 1c.
With respect to this polymer compound 1c, the mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 17,000, and the molecular weight dispersity (Mw / Mn) was 2.07. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m = 65.6 / 34. 4.

[Polymer Synthesis Example 2 (Synthesis of Polymer Compound 2c)]
To a three-necked flask connected with a thermometer and a reflux tube, 0.89 g (3.1 mmol) of compound 4c was added and dissolved in 1.89 g of tetrahydrofuran. To this solution, 0.07 g of dimethyl azobisisobutyrate (V-601) was added as a polymerization initiator and dissolved. This reaction solution was subjected to a polymerization reaction at 80 ° C. for 5 hours in a nitrogen atmosphere, and then cooled to room temperature. The obtained reaction polymerization solution was dropped into a large amount of n-heptane, and an operation for precipitating the polymer was performed. The precipitated white powder was filtered off, washed and dried, and the target polymer compound 2 was added in an amount of 0.0. 4 g was obtained.
With respect to this polymer compound 2c, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 9,000, and the molecular weight dispersity (Mw / Mn) was 1.97.

[Polymer synthesis examples 3 to 5 (synthesis of polymer compounds 3c to 5c)]
In the above [Monomer Synthesis Example 1], propylene glycol monomethyl ether (PGME) was changed to an organic solvent (equal molar amount) shown in Table 1 below to synthesize compounds 5c to 7c. Next, in [Polymer synthesis example 2], compound 4c was changed to compounds 5c to 7c (equal molar amount), respectively, to obtain polymer compounds 3c to 5c.
For each polymer compound, the mass average molecular weight and molecular weight dispersity (Mw / Mn) in terms of standard polystyrene determined by GPC measurement are also shown in Table 1.

[Examples 1-2, Comparative Examples 1-2]
Each component shown in Table 2 was mixed and dissolved to prepare a positive resist composition.

In Table 2, the numerical value in [] shows a compounding quantity (part by mass). Moreover, the symbol in Table 2 shows the following, respectively.
(A) -1: a polymer compound (A) -1 represented by the following chemical formula (A) -1.
(A) -2: a polymer compound (A) -2 represented by the following chemical formula (A) -2.
(B) -1: a compound represented by the following chemical formula (B) -1.
(B) -2: Triphenylsulfonium d-camphor-10-sulfonate.
(C) -1: the polymer compound 1c.
(C) -2: the polymer compound 2c.
(C) -3: A compound represented by the following chemical formula (C) -3. [Mw = 9500, Mw / Mn = 1.96. ]
(C) -4: A compound represented by the following chemical formula (C) -4. [Mw = 9600, Mw / Mn = 1.93. ]
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: γ-butyrolactone.
(S) -2: Mixed solvent of PGMEA / PGME = 60/40 (mass ratio).

［Ｍｗ＝１００００、Ｍｗ／Ｍｎ＝１．６。なお、（ ）の右下の数値は、各構成単位の割合（モル比）を示す。］

[Mw = 10000, Mw / Mn = 1.6. In addition, the numerical value of the lower right of () shows the ratio (molar ratio) of each structural unit. ]

［Ｍｗ＝７０００、Ｍｗ／Ｍｎ＝１．６。なお、（ ）の右下の数値は、各構成単位の割合（モル比）を示す。］

[Mw = 7000, Mw / Mn = 1.6. In addition, the numerical value of the lower right of () shows the ratio (molar ratio) of each structural unit. ]

<Measurement of receding angle in resist film>
On the 8-inch silicon wafer subjected to hexamethyldisilazane (HMDS) treatment, each of the resist compositions of Examples 1-2 and Comparative Examples 1-2 prepared in Table 2 was applied using a spinner. A pre-baking (PAB) process was performed on the plate under conditions of 110 ° C. for 60 seconds and dried to form a resist film having a thickness of 130 nm.
Next, water was dropped on the surface of the resist film (resist film before exposure), and the receding angle was measured using DROP MASTER-700 (product name, manufactured by Kyowa Interface Science Co., Ltd.) (receding angle). Of water: 2 μL of water). The measured value was defined as “retraction angle after application (°)”.
Each wafer after the receding angle measurement after coating was subjected to an alkali development treatment with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 23 ° C. for 30 seconds, and then rinsed with pure water for 15 seconds. Each of the receding angles was measured in the same manner as described above. This measured value was defined as “retraction angle after development (°)”.
In Examples 1 and 2 and Comparative Examples 1 and 2, the difference between the post-application receding angle and the post-development receding angle was determined and designated as “Δ receding angle °”. These results are shown in Table 3.

  From the above results, the resist films formed using the resist compositions of Examples 1 and 2 according to the present invention are after application compared to the resist films formed using the resist compositions of Comparative Examples 1 and 2. It was confirmed that the difference between the receding angle and the developing receding angle was large. The resist composition according to the present invention is expected to improve both the scan followability and the elution reduction effect during the immersion scan exposure by increasing the hydrophilicity after development.

Claims (7)

A base component (A) whose solubility in an alkaline developer is changed by the action of an acid;
An acid generator component (B) that generates an acid upon exposure; and
A fluorine-containing polymer compound (C) exhibiting decomposability to an alkali developer,
A resist composition dissolved in an organic solvent (S),
The fluorine-containing polymer compound (C) is a structural unit (c0-1) represented by the following general formula (c0-1) or a structural unit (c0-2) represented by the following general formula (c0-2). )
The said organic solvent (S) has the alcohol type organic solvent represented by the following general formula (s-0), The resist composition characterized by the above-mentioned.

[Wherein, each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and X is a divalent alkyl group that may have a fluorine atom. A linking group, A _aryl is an aromatic cyclic group which may have a substituent, X ₀₁ is a divalent linking group which may have a single bond or a fluorine atom, R R ² is a hydrocarbon group having 1 to 10 carbon atoms, wherein the hydrogen atom of the hydrocarbon group may be substituted with a hydroxyl group, and CH ₂ of the hydrocarbon group is substituted with a carbonyl group or an oxygen atom. May be. Incidentally, ^{R 2} in the formula (C0-1) and formula (C0-2) is a common radical and ^{R 2} in an alcoholic solvent represented by the formula (s-0). ]   The resist composition according to claim 1, wherein the base component (A) is a base component whose solubility in an alkali developer is increased by the action of an acid.   The resist composition according to claim 2, wherein the substrate component (A) is a resin component (A1) and has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.   The resist composition according to claim 3, wherein the substrate component (A) further comprises a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.   The resist composition according to claim 3 or 4, wherein the substrate component (A) further comprises a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.   Furthermore, the resist composition as described in any one of Claims 1-5 containing a nitrogen-containing organic compound component (D).   A step of forming a resist film on a support using the resist composition according to any one of claims 1 to 6, a step of exposing the resist film, and an alkali development of the resist film to form a resist pattern A resist pattern forming method including a forming step.

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