JP5331455B2 - Resist composition, resist pattern forming method, novel compound and acid generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new compound, to provide an acid-generating agent by using the compound, to provide a resist composition containing the acid-generating agent, and to provide a resist pattern-forming method using the resist composition. <P>SOLUTION: The resist composition contains a base material component (A) changing the solubility in an alkali developing liquid by the action of an acid, and an acid-generating agent component (B) containing a compound represented by formula (b1-1) (wherein, R<SP>1</SP>" to R<SP>3</SP>" are each aryl or alkyl, with the proviso that at least one thereof is substituted aryl substituted with a group represented by formula (b1-1-0), and any two thereof may form a ring by bonding to each other in combination with sulfur in the formula; X is a 3-30C hydrocarbon; Q<SP>2</SP>is a single bond or alkylene; p is an integer of 1-3; and W is 2-10C alkylene). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a resist composition, a method for forming a resist pattern using the resist composition, a novel compound useful as an acid generator for the resist composition, and an acid generator.

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 that satisfies such requirements, a chemically amplified resist containing a base resin 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. For example, a positive chemically amplified resist contains, as a base resin, a resin that increases solubility in an alkaline developer by the action of an acid and an acid generator. When the acid is generated, the exposed portion becomes soluble in the alkaline developer.

Up to now, as a base resin for chemically amplified resist, polyhydroxystyrene (PHS) having high transparency with respect to KrF excimer laser (248 nm) and a resin whose hydroxyl group is protected with an acid dissociable, dissolution inhibiting group (PHS resin) Has been used. However, since the PHS resin has an aromatic ring such as a benzene ring, the transparency to light having a wavelength shorter than 248 nm, for example, 193 nm, is not sufficient. For this reason, a chemically amplified resist having a PHS resin as a base resin component has drawbacks such as low resolution in a process using 193 nm light, for example. Therefore, as a resist base resin currently used in ArF excimer laser lithography and the like, it has a structural unit generally derived from a (meth) acrylic acid ester in the main chain because it is excellent in transparency near 193 nm. Resin (acrylic resin) is used. In the case of the positive type, such a resin includes a structural unit derived from a (meth) acrylic acid ester containing a tertiary alkyl ester type acid dissociable, dissolution inhibiting group containing an aliphatic polycyclic group, for example, 2-alkyl. Resins having structural units derived from 2-adamantyl (meth) acrylate or the like are mainly used (see, for example, Patent Document 1).
The “(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. “(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.

On the other hand, various acid generators used in chemically amplified resists have been proposed so far, such as onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, Diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators and the like are known.
Currently, an onium salt acid generator having an onium ion such as triphenylsulfonium in the cation moiety is used as the acid generator. As the anion part of the onium salt-based acid generator, an alkyl sulfonate ion or a fluorinated alkyl sulfonate ion in which part or all of the hydrogen atoms of the alkyl group are substituted with a fluorine atom is used (for example, patents). Reference 2).
JP 2003-241385 A JP 2005-037888 A

Among the onium salt acid generators as described above, onium salt acid generators having a perfluoroalkylsulfonic acid ion in the anion moiety are generally used at present.
However, in recent years, resist patterns have become increasingly finer, and conventional resist compositions containing onium salt-based acid generators having perfluoroalkylsulfonic acid ions in the anion moiety have resist pattern shapes and various lithographic properties. Further improvement is demanded.
In contrast, there is a need for new compounds that are more useful as acid generators for resist compositions.
The present invention has been made in view of the above circumstances, and is a novel compound useful as an acid generator for a resist composition, an acid generator using the compound, and a resist composition containing the acid generator It is an object to provide an object and a resist pattern forming method using the same.

  In order to solve the above problems, the present invention employs the following configuration.

  That is, the first aspect of the present invention is a resist composition comprising a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure. The acid generator component (B) is a resist composition containing an acid generator (B1) composed of a compound represented by the following general formula (b1-1).

［式（ｂ１−１）中、Ｒ^１”〜Ｒ^３”はそれぞれ独立に置換基を有していてもよいアリール基又はアルキル基を表し、Ｒ^１”〜Ｒ^３”のうち少なくとも１つは、水素原子の一部が下記一般式（ｂ１−１−０）で表される基で置換された置換アリール基であり、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い。Ｘは置換基を有していてもよい炭素数３〜３０の炭化水素基であり、Ｑ^２は単結合又はアルキレン基であり、ｐは１〜３の整数である。］

[In formula (b1-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent, and at least one of R ¹ ″ to R ³ ″ is , A substituted aryl group in which some of the hydrogen atoms are substituted with a group represented by the following general formula (b1-1-0), and any two of R ¹ ″ to R ³ ″ are bonded to each other. A ring may be formed together with the sulfur atom in the formula. X is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ² is a single bond or an alkylene group, and p is an integer of 1 to 3. ]

［式（ｂ１−１−０）中、Ｗは炭素数２〜１０の直鎖状又は分岐鎖状のアルキレン基である。］

[In Formula (b1-1-0), W represents a linear or branched alkylene group having 2 to 10 carbon atoms. ]

  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 development of the resist film. A resist pattern forming method including a step of forming a resist pattern.

  A third aspect of the present invention is a compound represented by the following general formula (b1-1).

［式（ｂ１−１）中、Ｒ^１”〜Ｒ^３”はそれぞれ独立に置換基を有していてもよいアリール基又はアルキル基を表し、Ｒ^１”〜Ｒ^３”のうち少なくとも１つは、水素原子の一部が下記一般式（ｂ１−１−０）で表される基で置換された置換アリール基であり、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い。Ｘは置換基を有していてもよい炭素数３〜３０の炭化水素基であり、Ｑ^２は単結合又はアルキレン基であり、ｐは１〜３の整数である。］

[In formula (b1-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent, and at least one of R ¹ ″ to R ³ ″ is , A substituted aryl group in which some of the hydrogen atoms are substituted with a group represented by the following general formula (b1-1-0), and any two of R ¹ ″ to R ³ ″ are bonded to each other. A ring may be formed together with the sulfur atom in the formula. X is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ² is a single bond or an alkylene group, and p is an integer of 1 to 3. ]

［式（ｂ１−１−０）中、Ｗは炭素数２〜１０の直鎖状又は分岐鎖状のアルキレン基である。］

[In Formula (b1-1-0), W represents a linear or branched alkylene group having 2 to 10 carbon atoms. ]

  A fourth aspect of the present invention is an acid generator comprising the compound of the third aspect.

In the present specification and claims, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
Further, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
The “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
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.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

  The present invention provides a novel compound useful as an acid generator for a resist composition, an acid generator using the compound, a resist composition containing the acid generator, and a resist pattern forming method using the compound. it can.

≪Resist composition≫
The resist composition according to the first aspect of the present invention comprises a base component (A) (hereinafter referred to as “component (A)”) whose solubility in an alkaline developer is changed by the action of an acid, and an acid upon exposure. Contains the generated acid generator component (B) (hereinafter referred to as “component (B)”).
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 alkali developer changes, the solubility of the unexposed portion in the alkali developer does not change. However, in the case of the negative type, the unexposed portion is dissolved and removed to form a resist pattern.
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.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
The organic compound having a molecular weight of 500 or more is largely classified into a low molecular weight organic compound having a molecular weight of 500 or more and less than 2000 (hereinafter referred to as a low molecular compound) and a high molecular weight resin having a molecular weight of 2000 or more (polymer material). Separated. As the low molecular weight compound, a non-polymer is usually used. In the case of a resin (polymer, copolymer), a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used as the “molecular weight”. Hereinafter, the term “resin” refers to a resin having a molecular weight of 2000 or more.
As the component (A), a resin whose alkali solubility is changed by the action of an acid can be used, and a low molecular weight material whose alkali solubility is changed by the action of an acid can also be used.

When the resist composition of the present invention is a negative resist composition, as the component (A), a base material component that is soluble in an alkali developer is used, and a crosslinking agent is further added to the negative resist composition.
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.
As the alkali-soluble resin, a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or a lower alkyl ester of α- (hydroxyalkyl) acrylic acid is a good resist with little swelling. A pattern can be formed, which is preferable. Α- (Hydroxyalkyl) acrylic acid includes 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 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.
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 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 component (A) is hardly soluble in an alkali developer before exposure. 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 this embodiment, the component (A1) preferably contains a structural unit derived from an acrylate ester.
Here, in the present specification and claims, the “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 include a lower alkyl group and a halogenated lower alkyl group.
Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
In the acrylate ester, as the lower alkyl group as a substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, Examples include lower linear or branched alkyl groups such as isopentyl group and neopentyl group.
Specific examples of the halogenated lower alkyl group include groups in which part or all of the hydrogen atoms in the above-mentioned “lower alkyl group as a substituent at the α-position” are 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.
In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and is a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group. In view of industrial availability, a hydrogen atom or a methyl group is most preferable.

The component (A1) particularly preferably 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 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)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). 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.

“Aliphatic branched” 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 a lower alkyl group having 1 to 5 carbon atoms, a lower alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O) and the like.
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 monocycloalkanes, bicycloalkanes, tricycloalkanes, tetracycloalkanes which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. And groups obtained by removing one or more hydrogen atoms from a polycycloalkane. More specifically, 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 are exemplified. .

  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—) An aliphatic cyclic group such as a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecanyl group, or a tetracyclododecanyl group, and a branched alkylene group having a tertiary carbon atom bonded thereto. Groups.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；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。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹⁵ and R ^{16 each} represents an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms. Is). ]

  In the general formulas (a1 ″ -1) to (a1 ″ -6), the lower alkyl group or halogenated lower alkyl group of R is a lower alkyl group or halogenated lower alkyl which may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group.

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低級アルキル基を表し、ｎは０〜３の整数を表し、Ｙは低級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 a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or 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 lower alkyl group for R ¹ ′ and R ² ′ include the same lower alkyl groups as those described above for R. A methyl group or an ethyl group is preferable, and a methyl group is most 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 lower alkyl group for Y include the same lower alkyl groups as those described above for 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 above “aliphatic ring” 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もしく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} the end of R ¹⁷ And may be combined.
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、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and X ¹ represents an acid dissociable, dissolution inhibiting group. ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；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, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents a divalent linking group. ]

In general formula (a1-0-1), the lower alkyl group or halogenated lower alkyl group for R is the same as the lower alkyl group or halogenated lower alkyl group that may be bonded to the α-position of the acrylate ester. .
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—, “—Y ^a —O (oxygen atom) —Y ^b — (Y ^a and Y ^b are each independently a substituent. And a divalent hydrocarbon group which may have a hydrogen 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 “Y ^a —O—Y ^b ”, Y ^a and Y ^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 for Y ^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 Y ^a may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for Y ^a include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group having 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 - _{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 Alkylethylene groups such as CH ₃ ) CH ₂ —; alkyltrimethylene 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 - , etc. And alkyl alkylene groups such as Le Kill tetramethylene group. 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 lower 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 bonded to the terminal of the aromatic hydrocarbon group or interposed 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 a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

As Y ^a , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 2 to 5 carbon atoms is further preferable, and an ethylene group is most preferable.

Examples of the hydrocarbon group for Y ^b include the same divalent hydrocarbon groups as those described above for Y ^a .
Y ^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の低級アルキル基、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の低級アルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower 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 a lower alkyl group having 1 to 5 carbon atoms. ]

In the formula, X 'can be mentioned 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 formulae, 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) or (a1-3) is preferable, and specifically, (a1-1-1) to (a1-1-4), (a1-1-1-) It is more preferable to use at least one selected from the group consisting of 20) to (a1-1-23) and (a1-3-25) to (a1-3-28).
Furthermore, as the structural unit (a1), those represented by the following general formula (a1-1-01) that include structural units of the formula (a1-1-1) to the formula (a1-1-3), In the following general formula (a1-1-02) including the structural units of formulas (a1-1-16) to (a1-1-17) and formulas (a1-1-20) to (a1-1-23) Represented by the following general formula (a1-3-01) including structural units of the formulas (a1-3-25) to (a1-3-26), or the formula (a1-3- What is represented by the following general formula (a1-3-02) including the structural units of 27) to (a1-3-28) is also preferable.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１１は低級アルキル基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group. ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜６の整数を表す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹² represents a lower alkyl group. h represents an integer of 1 to 6. ]

In general formula (a1-1-01), R is the same as defined above.
The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.
In general formula (a1-1-02), R is the same as defined above.
The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 to 4, and most preferably 4.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１４は低級アルキル基であり、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, a lower alkyl group or a halogenated lower alkyl group; R ¹⁴ represents a lower alkyl group, R ¹³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 10. . ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１４は低級アルキル基であり、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, a lower alkyl group or a halogenated lower alkyl group; R ¹⁴ represents a lower alkyl group, R ¹³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 10. , N ′ is an integer of 1-6. ]

In the general formula (a1-3-01) or (a1-3-02), R is the same as described above.
R ¹³ is preferably a hydrogen atom.
The lower alkyl group for R ^{14 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.
a is preferably an integer of 1 to 8, more preferably an integer of 2 to 5, and most preferably 2.

In the component (A1), as the structural unit (a1), one type of structural unit may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, more preferably 25 to 50 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.
The lactone cyclic group of the structural unit (a2) has an affinity for a developer containing water or a high-molecular compound (A1) when the polymer film (A1) is used for forming a resist film. It is effective in improving the sex.

As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, as the lactone-containing monocyclic group, a group in which one hydrogen atom is removed from a 4- to 6-membered ring lactone, for example, a group in which one hydrogen atom is removed from β-propionolactone, 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、低級アルキル基またはハロゲン化低級アルキル基であり；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または１〜２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の整数である。］

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

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
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.

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.

  A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

R ²⁹ is a single bond or a divalent linking group. The divalent linking group is the same as the divalent linking group described for Y ² in the general formula (a1-0-2), and among them, an alkylene group and an ester bond (—C (═O ) -O-) or a combination thereof. 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 A in Y ² can be used.

s ″ is preferably an integer of 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.

  As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formulas (a2-1) to ( At least one selected from the group consisting of structural units represented by a2-3) is more preferred. Among them, structural units represented by chemical formulas (a2-1-1), (a2-2-1), (a2-2-7), (a2-3-1), and (a2-3-5) It is preferable to use at least one selected from the group consisting of

In the component (A1), as the structural unit (a2), one type of structural unit may be used, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, with respect to the total of all the structural units constituting the component (A1). 50 mol% is more preferable. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.

・ 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 (A1) 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.
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, a structural unit represented by the following formula (a3-1), a structural unit represented by (a3-2), (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 the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, and l is an integer of 1 to 5] And s is an integer 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 3rd 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. These preferably have a 2-norbornyl group or a 3-norbornyl group 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.

In the component (A1), as the structural unit (a3), one type of structural unit 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 5 to 50 mol%, more preferably 5 to 40 mol%, and more preferably 5 to 25 mol% with respect to all the structural units constituting the component (A1). Is more preferable. 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.

・ Structural unit (a4)
The component (A1) may contain other structural units (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.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group is 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. ]

When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) in the component (A1) is 1 to 30 with respect to the total of all structural units constituting the component (A1). Mol% is preferable and 10 to 20 mol% is more preferable.
Moreover, when making it contain in (A1) component, a structural unit (a4) may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the present invention, the component (A1) preferably contains a copolymer having the structural units (a1), (a2) and (a3). Examples of the copolymer include copolymers composed of the structural units (a1), (a2) and (a3), copolymers composed of the structural units (a1), (a2), (a3) and (a4). Can be mentioned. Moreover, as this copolymer, 1 type may be used independently and 2 or more types may be used together.

The component (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000, and 5000 to 20000. Most preferred. If it is smaller than the upper limit of this range, there is sufficient solubility in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows a number average molecular weight.

[(A2) component]
As the component (A2), a low molecular compound having a molecular weight of 500 or more and less than 2000 and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of the component (A1) above is preferable. 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, 3, 4 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol or xylenol. Of course, it is not limited to these.
The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.

As the component (A), one type may be used alone, or two or more types may be used in combination.
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>
In this invention, (B) component contains the acid generator (B1) (henceforth "(B1) component") consisting of a compound represented by the following general formula (b1-1).

［式（ｂ１−１）中、Ｒ^１”〜Ｒ^３”はそれぞれ独立に置換基を有していてもよいアリール基又はアルキル基を表し、Ｒ^１”〜Ｒ^３”のうち少なくとも１つは、水素原子の一部が下記一般式（ｂ１−１−０）で表される基で置換された置換アリール基であり、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い。Ｘは置換基を有していてもよい炭素数３〜３０の炭化水素基であり、Ｑ^２は単結合又はアルキレン基であり、ｐは１〜３の整数である。］

[In formula (b1-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent, and at least one of R ¹ ″ to R ³ ″ is , A substituted aryl group in which some of the hydrogen atoms are substituted with a group represented by the following general formula (b1-1-0), and any two of R ¹ ″ to R ³ ″ are bonded to each other. A ring may be formed together with the sulfur atom in the formula. X is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ² is a single bond or an alkylene group, and p is an integer of 1 to 3. ]

［式（ｂ１−１−０）中、Ｗは炭素数２〜１０の直鎖状又は分岐鎖状のアルキレン基である。］

[In Formula (b1-1-0), W represents a linear or branched alkylene group having 2 to 10 carbon atoms. ]

-About the cation part of (B1) component In said formula (b1-1), R < ¹ >''-R< ³ >'' has the aryl group or substituent which may have a substituent each independently. A substituted aryl group in which at least one of R ¹ ″ to R ³ ″ is a hydrogen atom partially substituted with a group represented by the general formula (b1-1-0) It is.
That is, at least one of R ¹ ″ to R ³ ″ is an aryl group. In the present ^invention, it is preferable that two or more of R 1 "~R ^3" is an aryl ^group, it is particularly desirable that all of R 1 "~R ^3" are aryl groups.
Here, the aryl group or alkyl group has a “substituent” means that part or all of the hydrogen atoms in the aryl group or alkyl group are substituted with atoms or groups other than hydrogen atoms. To do.

The aryl group for R ¹ ″ to R ³ ″ is not particularly limited. For example, an aryl group having 6 to 20 carbon atoms is preferable, and an aryl group having 6 to 10 carbon atoms is preferable because it can be synthesized at low cost. Specific examples include a phenyl group and a naphthyl group.

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 decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.

Among the above, R ¹ ″ to R ³ ″ are each preferably an aryl group which may have a substituent, and a phenyl group or a naphthyl group which may have a substituent. More preferably. Among them, all of R 1 ^{"~R 3"} is particularly preferably an aryl group which may have a substituent group, all R 1 ^{"~R 3"} is substituted Most preferably, it may be a phenyl group or a naphthyl group.

In the formula (b1-1), at least one of R ¹ ″ to R ³ ″ is a substitution in which a part of hydrogen atoms is substituted with a group represented by the general formula (b1-1-0) An aryl group.
The “part of hydrogen atom” specifically means preferably 1 to 4 hydrogen atoms, more preferably 1 to 3 hydrogen atoms, and particularly preferably 1 hydrogen atom.

In said formula (b1-1-0), W is a C2-C10 linear alkylene group or a C2-C10 branched alkylene group.
The carbon number in W is 2-10, 2-9 are preferable, 2-5 are more preferable, specifically, 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 -, - CH (CH 2 CH 3) CH 2 - alkyl ethylene such as Group; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; alkyl trimethylene group such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ — A tetramethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ —]; an alkyl tetramethylene group such as —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ CH ₂ —; A pentamethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —], hexamethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —], heptamethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH _2- ], octamethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —], nonamethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -], decamethylene _{[-CH 2 CH 2 CH 2 CH} 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 -] and the like.
Among them, an ethylene group, a butylene group, and a nonamethylene group are preferable, and an ethylene group is particularly preferable because the lithography properties and the resist pattern shape are good and can be synthesized at low cost.

The aryl group or alkyl group of R ¹ ″ to R ³ ″ may have a substituent other than the group represented by the formula (b1-1-0).
Examples of the substituent that the aryl group or the alkyl group may have include an alkyl group, an alkoxy group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, a halogen atom, a hydroxyl group,-(R ⁴ ') -C (= O ) -R ⁵ 'and the like. R ⁴ ′ is an alkylene group having 1 to 5 carbon atoms. R ⁵ ′ is an aryl group. As the aryl group for R ⁵ ′, the same aryl groups as those described above for R ¹ ″ to R ³ ″ can be used.

The alkyl group in the substituent of R ¹ ″ to R ³ ″ is preferably an alkyl group having 1 to 5 carbon atoms, particularly preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Preferably, it is a methyl group.
The alkoxy group in the substituent of R ¹ ″ to R ³ ″ 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- Particularly preferred is a butoxy group.
The halogen atom in the substituent for R ¹ ″ to R ³ ″ is preferably a fluorine atom.

Examples of the alkoxyalkyloxy group in the substituent of R ¹ ″ to R ³ ″ include, for example,
General formula: -O-C ( ^R47 ) ( ^R48 ) -O- ^R49
[Wherein, R ⁴⁷ and R ⁴⁸ each independently represent a hydrogen atom or a linear or branched alkyl group, and R ⁴⁹ represents an alkyl group. ] Is represented.
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms, may be linear or branched, more preferably an ethyl group or a methyl group, and most preferably a methyl group.
At least one of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom. In particular, it is more preferable that one is a hydrogen atom and the other is a hydrogen atom or a methyl group.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms, and may be linear, branched or cyclic.
The linear or branched alkyl group for R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. Can be mentioned.
The cyclic alkyl group for R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms.
Specifically, a monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane 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. Groups obtained by removing one or more hydrogen atoms from polycycloalkanes and the like. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.

Examples of the alkoxycarbonylalkyloxy group in the substituent of R ¹ ″ to R ³ ″ include, for example,
General formula: —O—R ⁵⁰ —C (═O) —O—R ⁵¹
[Wherein, R ⁵⁰ represents a linear or branched alkylene group, and R ⁵¹ represents a tertiary alkyl group. ] Is represented.
The linear or branched alkylene group for R ⁵⁰ preferably has 1 to 5 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, or a 1,1-dimethylethylene group. Etc.
As the tertiary alkyl group for R ⁵¹ , 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group, 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-methyl -1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 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 group; 1- (1-cyclohexyl) -1-methylethyl Group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl) -1-methylpentyl group, tert-butyl group, tert -Pentyl group, tert-hexyl group and the like.

Any two of R ¹ ″ to R ³ ″ in the formula (b1-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
In such a case, it is preferable to form a 3- to 10-membered ring including a sulfur atom, and it is particularly preferable to form a 5- to 7-membered ring.
When any two of R ¹ ″ to R ³ ″ in formula (b1-1) 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 remaining one aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″.

  Preferred specific examples of the cation moiety of the component (B1) are listed below.

［式中、ｆ１は２〜１０の整数であり、ｆ２は１〜３の整数であり、Ｒ^４１’は炭素数１〜５のアルキル基であり、ｎ_１’は０〜３の整数である。］

[Wherein, f1 is an integer of 2 to 10, f2 is an integer of 1 to 3, R ⁴¹ ′ is an alkyl group having 1 to 5 carbon atoms, and n ₁ ′ is an integer of 0 to 3] . ]

In said formula (b1-2-1), f1 is an integer of 2-10, 2-9 are preferable, 2-5 are more preferable, and 2 is the most preferable.
R ⁴¹ ′ is an alkyl group having 1 to 5 carbon atoms, preferably linear or branched, and may be a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. More preferred is a methyl group.
n ₁ ′ is an integer of 0 to 3, preferably 1 or 2, and particularly preferably 2.
When n ₁ ′ is not 0, R ⁴¹ ′ is bonded at the terminal oxygen atom of the group represented by the formula “—O— (CH ₂ ) _{f 1} —O—CH═CH ₂ ”. A carbon atom adjacent to a carbon atom in the ring is preferable.

In said formula (b1-2-2), f2 is an integer of 1-3, 1-2 are preferable and 1 is the most preferable.
R ⁴¹ ′ and n ₁ ′ are the same as described above.
When n ₁ ′ is not 0, the bonding position of R ⁴¹ ′ is the oxygen atom at the end of the group represented by the formula “—O— (CH ₂ —CH (CH ₃ )) _{f 2} —O—CH═CH ₂ ”. Is preferably a carbon atom adjacent to the carbon atom in the benzene ring to which is bonded.

-About the anion part of (B1) component In said formula (b1-1), X is a C3-C30 hydrocarbon group which may have a substituent.
The hydrocarbon group for 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 has 3 to 30 carbon atoms, preferably 5 to 30, more preferably 5 to 20, particularly 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 group removed by one; arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, and the like. 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. In such a case, in the partial structure “XQ ² —” of the anion moiety in the general formula (b1-1), the atom where X is bonded to Q ² is preferably a carbon atom.
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, or a combination thereof.
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 substituents for substituting part or all of the hydrogen atoms include substituents containing nitrogen atoms such as alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxyl groups, oxygen atoms (═O), cyano groups, and the like. Etc.
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. A group in which a linear or branched saturated hydrocarbon group or unsaturated hydrocarbon group is bonded to an aliphatic cyclic group is also preferred.

The linear 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, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group 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 3-10, 3-5 are preferable, 3 or 4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include 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 3-30, preferably 5-30, more preferably 5-20, particularly preferably 6-15, and most preferably 6-12.
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 one or more hydrogen atoms from the polycycloalkane are substituted. 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^９８−または−Ｓ−Ｒ^９９−であり、Ｒ^９８およびＲ^９９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 ⁹⁸ — or —S—R ⁹⁹ —, and R ⁹⁸ and R ⁹⁹ are each independently carbon. An alkylene group of 1 to 5, and m is an integer of 0 or 1.]

In the formula, specific examples of the alkylene group in Q ″, R ⁹⁸ and R ⁹⁹ include, for example, 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 - An alkylmethylene group 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 -, - CH (CH 2 CH 3) CH 2 - alkyl groups such as, trimethylene group (n- propylene _{group) [- CH 2 CH 2 CH} 2 -]; - _{CH (CH 3) CH 2 CH} 2 -, - CH 2 CH ( Tetramethylene group _{[-CH 2 CH 2 CH 2 CH} 2 -];; - H 3) CH 2 alkyltetramethylene groups such as _{- CH (CH 3) CH 2} CH 2 CH 2 -, - CH 2 CH (CH 3 ) _{CH 2 CH} 2 - and the like alkyl tetramethylene group; pentamethylene group _{[-CH 2 CH 2 CH 2 CH} 2 CH 2 -] , and the like.

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.

  Examples of the group in which a linear or branched saturated hydrocarbon group or unsaturated hydrocarbon group is bonded to an aliphatic cyclic group include, for example, a direct bond to a carbon atom constituting the ring structure of the aliphatic cyclic group. A group in which a linear or branched saturated hydrocarbon group is bonded is preferable, a group in which a linear saturated hydrocarbon group is bonded to the carbon atom is more preferable, and a linear alkylene group is bonded to the carbon atom. The group is particularly preferred.

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, or an aliphatic cyclic group which may have a substituent.
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, the above (L2) to (L5), (S3) to (S4), and the like.

In formula (b1-1), Q ² represents a single bond or an alkylene group.
The alkylene group for Q ² 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.
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 —, Alkylethylene groups such as —CH (CH ₂ CH ₃ ) CH ₂ —; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ CH ₂ —, —CH _{2 CH (CH 3) CH 2} - alkyl trimethylene group and the like; Toramechiren group _{[-CH 2 CH 2 CH 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; penta And methylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like.

  In the formula (b1-1), p is an integer of 1 to 3, preferably 1 or 2, and most preferably 2.

  Preferred specific examples of the anion moiety of the component (B1) are listed below.

［式中、Ｒ^７は置換基であり、ｗ１〜ｗ３はそれぞれ独立に０〜３の整数であり、ｖ１〜ｖ３はそれぞれ独立に０〜５の整数であり、ｐは１〜３の整数である。］

[Wherein R ⁷ is a substituent, w1 to w3 are each independently an integer of 0 to 3, v1 to v3 are each independently an integer of 0 to 5, and p is an integer of 1 to 3. is there. ]

In the above formula, as the substituent of R ⁷ , in X, the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have The same thing is mentioned.
If signs placed R ⁷ (w1 to w3) is an integer of 2 or more, a plurality of the R ⁷ groups may be the same, respectively, may be different.
v1 to v3 are each independently preferably 0 to 3, and more preferably 0 or 1.
w1 to w3 are each independently preferably 0 to 2, and most preferably 0.
p is preferably 1 or 2, and most preferably 2.

As the component (B1), one type may be used alone, or two or more types may be used in combination.
The content ratio of the component (B1) is preferably in the range of 0.5 to 60 parts by mass and more preferably in the range of 1 to 40 parts by mass with respect to 100 parts by mass of the component (A). , Particularly preferably in the range of 3 to 30 parts by mass. When the content ratio of the component (B1) is not less than the lower limit of the above range, the lithography properties are further improved when a resist composition is obtained. Further, a better resist pattern shape can be obtained. It is preferable for it to be not more than the upper limit of the above range, since a uniform solution can be obtained and the storage stability becomes good.

  In the resist composition of the present invention, the content ratio of the component (B1) in the component (B) is preferably 40% by mass or more, more preferably 70% by mass or more, and even 100% by mass. Good. Most preferably, it is 100 mass%. When the content ratio of the component (B1) is not less than the lower limit of the above range, the lithography properties are further improved when a resist composition is obtained. Further, a better resist pattern shape can be obtained.

[(B2) component]
In the resist composition of the present invention, in addition to the component (B1), the component (B) contains an acid generator other than the component (B1) (hereinafter referred to as “component (B2)”) as necessary. You may contain.
The component (B2) is not particularly limited as long as it does not correspond to the component (B1), and any of 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^７”〜Ｒ^９”，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^７”〜Ｒ^９”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、直鎖状、分岐鎖状または環状のアルキル基またはフッ素化アルキル基を表し；Ｒ^７”〜Ｒ^９”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 ⁷ ″ to R ⁹ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; among R ⁷ ″ to R ⁹ ″ in formula (b-1), Any two may be bonded together to form a ring with the sulfur atom in the formula; R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group; R ⁷ At least one of “˜R ⁹ ” represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ”represents an aryl group.]

In formula (b-1), R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group. In addition, any two of R ⁷ ″ to R ⁹ ″ 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 ⁷ ″ to R ⁹ ″ represents an aryl group. Of R ⁷ ″ to R ⁹ ″, two or more are preferably aryl groups, and most preferably R ⁷ ″ to R ⁹ ″ are all aryl groups.
The aryl group for R ⁷ ″ to R ⁹ ″ 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, Most preferred is a tert-butoxy group.
The alkoxy group that may be substituted for the hydrogen atom of the aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and most preferably a methoxy group or an ethoxy group.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
The alkyl group for R ⁷ ″ to R ⁹ ″ is not particularly limited, and examples thereof include a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. 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 decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
Among these, R ⁷ ″ to R ⁹ ″ are most preferably a phenyl group or a naphthyl group, respectively.

When any two of R ⁷ ″ to R ⁹ ″ in 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 is formed including the sulfur atom. It is preferable that a 5- to 7-membered ring is formed.
When any two of R ⁷ ″ to R ⁹ ″ 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 ⁷ ″ to R ⁹ ″.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group.
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 is a cyclic group as represented by R ⁷ ″, preferably having 4 to 15 carbon atoms, more preferably having 4 to 10 carbon atoms, and 6 carbon atoms. Most preferably, it is -10.
The fluorinated 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 fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. Particularly, all the hydrogen atoms are substituted with fluorine atoms. A fluorinated alkyl group (perfluoroalkyl group) is preferable because the strength of the acid is increased.
R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl 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 ⁷ ″ to R ⁹ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ⁷ ″ to R ⁹ ″.
Among these, it is most preferable that R ⁵ ″ to R ⁶ ″ are all phenyl groups.
"The, ^{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, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

  In addition, in the general formula (b-1) or (b-2), an onium salt-based acid generator in which the anion moiety is replaced with an anion moiety represented by the following general formula (b-3) or (b-4). 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 This is preferable because the transparency to the surface is improved.
The proportion 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 hydrogen atoms are substituted with fluorine atoms. A perfluoroalkylene group or a perfluoroalkyl group.

  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). An anion moiety represented by the general formula (b-3) or (b-4), etc. Among them, a fluorinated alkyl sulfonate ion is preferable, and a fluorinated alkyl sulfonic acid having 1 to 4 carbon atoms. Ion is more preferable, and linear perfluoroalkylsulfonic acid ions having 1 to 4 carbon atoms are particularly preferable, and specific examples thereof include trifluoromethylsulfonic acid ions, heptafluoro-n-propylsulfonic acid ions, and nonafluoro-n. -Butyl sulfonate ion etc. are mentioned.

  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 of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and 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 formula 18] to [chemical formula 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 85 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.

  (B2) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.

  0.5-60 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for the total content of (B) component in the resist composition of this invention, 1-40 mass parts is more preferable. 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.

<Optional component>
[(D) component]
The resist composition of the present invention preferably further contains a nitrogen-containing organic compound component (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 control agent, 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, it may be used arbitrarily from known ones, and among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine 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 12 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-pentylamine, tri-n-hexylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, etc .; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-pentylamine and tri-n-octylamine are particularly 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.
These may be used alone or in combination of two or more.
In the present invention, it is particularly preferable to use a trialkylamine having 5 to 10 carbon atoms as the component (D).
(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.

[(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 include phosphoric acid, phosphonic acid, and phosphinic acid. 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 used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

  The resist composition of the present invention further contains miscible additives as desired, for example, an additional resin for improving the performance of the resist film, a surfactant, a dissolution inhibitor, and a plasticizer for improving coatability. Stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.

[(S) component]
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter referred to as “(S) component”).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of 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, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, γ-butyrolactone, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, 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 as a polar solvent, 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.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of component (S) used is not particularly limited and 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 1 -20% by mass, preferably 1.5-15% by mass.

The resist composition of the present invention described above is a novel one that has not been known so far.
According to the resist composition of the present invention, in forming a fine resist pattern, it is possible to form a resist pattern with good lithography characteristics and shape such as improvement of exposure dose (EL) margin and improvement of resist pattern shape. The reason why such an effect is obtained is not clear, but is presumed as follows.
In the resist composition of the present invention, as the acid generator, an acid generator composed of the component (B1), that is, the compound represented by the general formula (b1-1) is used.
In the anion part of the component (B1), the hydrocarbon group (X) having 3 to 30 carbon atoms which may have a substituent in the skeleton of “—O— (CF ₂ ) _p —SO ₃ ^— ” is formed. , Having a structure bonded through a single bond or an alkylene group (—Q ² —). Therefore, the anion part of the component (B1) has a three-dimensionally bulky and bulky structure as compared with the fluorinated alkyl sulfonate ion conventionally used as the anion part of the onium salt acid generator. It is speculated that this bulky steric structure suppresses the diffusion of the anion part in the resist film chemically and physically compared to the anion part of a conventional acid generator such as nonafluorobutanesulfonate. . Therefore, by using the component (B1), diffusion of the acid generated in the exposed area to the unexposed area is suppressed, and as a result, the difference in alkali solubility (dissolution contrast) between the unexposed area and the exposed area is improved. By doing so, it is presumed that the resist pattern shape is improved. Further, even if there is some variation in the exposure dose, for example, sufficient acid is generated to dissociate the acid dissociable, dissolution inhibiting group in the structural unit (a1), so that the exposure dose (EL) margin is improved. Guessed.
Here, the “EL margin” refers to a range of exposure amount that can form a resist pattern with a dimension within which a deviation from a target dimension is within a predetermined range when exposure is performed while changing the exposure amount, that is, faithful to the mask pattern. This is the range of exposure amount from which a resist pattern can be obtained. The larger the EL margin value, the smaller the change amount of the pattern size accompanying the variation in exposure amount, and the better the process margin.

  Furthermore, according to the resist composition of the present invention, the shape when the resist pattern is formed, for example, the roundness and uniformity of the hole when the hole pattern is formed, and the line width roughness (LWR when the line pattern is formed). ), Line edge roughness (LER) and the like are improved. Although the reason is not clear, it is presumed that the reason is the same as the above-described improvement of the EL margin. “LWR” is a phenomenon in which the line width of the formed line pattern and “LER” is a phenomenon in which the side wall of the line pattern becomes non-uniform. Improvement of the pattern becomes more important as the pattern becomes finer.

≪Resist pattern formation method≫
The resist pattern forming method according to the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention, a step of exposing the resist film, And a step of alkali developing the resist film to form a resist pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition is coated on a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Then, after selectively exposing ArF excimer laser light through a desired mask pattern, for example, with an ArF exposure apparatus or the like, PEB (post-exposure heating) is performed for 40 to 120 seconds under a temperature condition of 80 to 150 ° C. Preferably, it is applied for 60 to 90 seconds. Subsequently, this is alkali-development-processed using alkaline developing solution, for example, 0.1-10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, Preferably, water rinse is carried out using a pure water, and it dries. In some cases, a baking treatment (post-baking) may be performed after the alkali development treatment. 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 the 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 of the present invention is more effective for KrF excimer laser, ArF excimer laser, EB or EUV, and particularly effective for ArF excimer laser.

The exposure 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.
In immersion exposure, at the time of exposure, a solvent (having a refractive index larger than the refractive index of air) is formed between a lens and a resist film on the wafer, which is conventionally filled with an inert gas such as air or nitrogen. Exposure is performed in a state filled with the immersion medium.
More specifically, the immersion exposure is a solvent (immersion medium) having a refractive index larger than the refractive index of air between the resist film obtained as described above and the lowermost lens of the exposure apparatus. And in that state, exposure can be performed through a desired mask pattern (immersion exposure).
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 exposed by the immersion exposure 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.).

≪Compound≫
The compound which is the third aspect of the present invention is a compound represented by the following general formula (b1-1). The compound is the same as the component (B1) contained in the component (B) of the resist composition according to the first aspect of the present invention described above.

［式（ｂ１−１）中、Ｒ^１”〜Ｒ^３”はそれぞれ独立に置換基を有していてもよいアリール基又はアルキル基を表し、Ｒ^１”〜Ｒ^３”のうち少なくとも１つは、水素原子の一部が下記一般式（ｂ１−１−０）で表される基で置換された置換アリール基であり、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い。Ｘは置換基を有していてもよい炭素数３〜３０の炭化水素基であり、Ｑ^２は単結合又はアルキレン基であり、ｐは１〜３の整数である。］

[In formula (b1-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent, and at least one of R ¹ ″ to R ³ ″ is , A substituted aryl group in which some of the hydrogen atoms are substituted with a group represented by the following general formula (b1-1-0), and any two of R ¹ ″ to R ³ ″ are bonded to each other. A ring may be formed together with the sulfur atom in the formula. X is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ² is a single bond or an alkylene group, and p is an integer of 1 to 3. ]

［式（ｂ１−１−０）中、Ｗは炭素数２〜１０の直鎖状又は分岐鎖状のアルキレン基である。］

[In Formula (b1-1-0), W represents a linear or branched alkylene group having 2 to 10 carbon atoms. ]

  The description about the compound of this invention is the same as the description about the said (B1) component.

(Method for producing compound)
The compound which is the third aspect of the present invention can be produced by a conventionally known method.
The compound of the present invention, that is, the compound represented by the general formula (b1-1), for example, the compound (b0-1-11) represented by the following general formula (b0-1-11), tetrahydrofuran, It is represented by the following general formula (b0-1) by reacting in an organic solvent such as acetone or methyl ethyl ketone, or an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or lithium hydroxide or an ammonium compound in a solvent such as water. To obtain the compound (b0-1). And it can manufacture by making the said compound (b0-1) and the compound (b0-2) represented by the following general formula (b0-2) react, for example in aqueous solution.

In the formulas (b0-1-11), (b0-1) and (b0-2), X, Q ² and p are the same as X, Q ² and p in the formula (b1-1), respectively. It is.
In the formula (b0-2), R ¹ ″ to R ³ ″ are the same as R ¹ ″ to R ³ ″ in the formula (b1-1), respectively.

In the formula (b0-1), M ⁺ is an alkali metal ion or an ammonium ion which may have a substituent.
Examples of the alkali metal ion include sodium ion, lithium ion, potassium ion and the like, and sodium ion or lithium ion is preferable.
As an ammonium ion which may have this substituent, what is represented by the following general formula (b1-2-2) is mentioned, for example.

［式中、Ｒ^３〜Ｒ^６はそれぞれ独立に水素原子、または置換基を有していてもよい炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも１つは前記炭化水素基であり、Ｒ^３〜Ｒ^６のうちの少なくとも２つがそれぞれ結合して環を形成していてもよい。］

[Wherein R ^{3 to} R ⁶ are each independently a hydrogen atom or an optionally substituted hydrocarbon group, and at least one of R ^{3 to} R ⁶ is the hydrocarbon group. , R ^{3 to} R ⁶ may be bonded to each other to form a ring. ]

In formula (b1-2-2), R ^{3 to} R ⁶ are each independently a hydrogen atom or an optionally substituted hydrocarbon group, and at least one of R ^{3 to} R ⁶ One is the hydrocarbon group.
Examples of the hydrocarbon group for R ^{3 to} R ⁶ include the same groups as those described above for X.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. When the hydrocarbon group is an aliphatic hydrocarbon group, the aliphatic hydrocarbon group is particularly preferably an alkyl group having 1 to 12 carbon atoms which may have a substituent.
It is preferable that at least one of R ^{3 to} R ⁶ is the hydrocarbon group, and two or three are the hydrocarbon groups.

At least two of R ^{3 to} R ⁶ may be bonded to each other to form a ring. For example, two of R ^{3 to} R ⁶ may be bonded to form one ring, or three of R ^{3 to} R ⁶ may be bonded to form a ring, Two of R ^{3 to} R ⁶ may be bonded to each other to form two rings.
The ring (heterocycle containing a nitrogen atom as a heteroatom) formed by combining at least two of R ^{3 to} R ⁶ with the nitrogen atom in the formula may be an aliphatic heterocycle or aromatic. It may be a heterocyclic ring. Further, the heterocyclic ring may be monocyclic or polycyclic.

Specific examples of the ammonium ion represented by the formula (b1-2-2) include an ammonium ion derived from an amine.
Here, the “ammonium ion derived from an amine” means a cation formed by bonding a hydrogen atom to the nitrogen atom of the amine, and a quaternary ammonium having one substituent bonded to the nitrogen atom of the amine. Ion.
The amine for deriving the ammonium ion may be an aliphatic amine or an aromatic amine.
As the aliphatic amine, an amine (alkyl amine 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 having 12 or less carbon atoms or a hydroxyalkyl group is particularly preferable.
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 , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, etc .; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine.
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.
Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine (DMAP), pyrrole, indole, pyrazole, imidazole and the like.
Examples of the quaternary ammonium ion include tetramethylammonium ion, tetraethylammonium ion, and tetrabutylammonium ion.

As the ammonium ion represented by the formula (b1-2-2), it is particularly preferable that at least one of R ^{3 to} R ⁶ is an alkyl group and at least one is a hydrogen atom.
Among them, three of R ^{3 to} R ⁶ are alkyl groups, and the remaining one is a hydrogen atom (trialkylammonium ion), or two of R ^{3 to} R ⁶ are alkyl groups. In addition, those in which the remaining one is a hydrogen atom (dialkylammonium ion) are preferable.
The alkyl group in the trialkylammonium ion or dialkylammonium ion preferably independently has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 5 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decanyl group. Of these, the ethyl group is most preferred.

In the formula (b0-2), Z ⁻ is a non-nucleophilic ion.
Examples of the non-nucleophilic ion include halogen ions such as bromine ion and chlorine ion, ions that can be acid having lower acidity than the compound (b0-1), BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ^- or ClO ₄ ^- and the like.
Z ^- as ion acidity than the compound (b0-1) can become a low acid in the, p- toluenesulfonate ion, methanesulfonate ion, and a sulfonate ion such as benzenesulfonate ion.

As the compound (b0-1-11), a commercially available product may be used, or it may be synthesized by a known method.
The production method of the compound (b0-1-11) is not particularly limited. For example, referring to the method described in Example 1 of JP-T-11-502543, silver fluoride (AgF) And a compound represented by the following general formula (b0-1-01) and a compound represented by the following general formula (b0-1-02) in an organic solvent such as anhydrous diglyme. Can be manufactured.
Examples of the halogen atom for _{X h} in the formula (b0-1-02), bromine atom or a chlorine atom is preferable.

［式中、Ｘ、Ｑ^２、ｐは、それぞれ前記式（ｂ０−１）中のＸ、Ｑ^２、ｐと同じであり、Ｘ_ｈはハロゲン原子である。］

Wherein, ^{X, Q} 2, p is, X in each of the formulas (b0-1) in ^the same as ^Q 2, p, _{X h} represents a halogen atom. ]

  The compound represented by the general formula (b0-1-01) can be produced by, for example, the method described in JP-A-2006-348382 and US Pat. No. 6,624,328B1.

The compound (b0-2) can be produced, for example, as follows.
First, a compound represented by the following general formula (b1-15-01) in a solution of an organic acid H ⁺ B ⁻ (B ⁻ represents an anion portion of an organic acid such as a methanesulfonate ion) After adding and reacting with the compound represented by the following general formula (b1-15-02), pure water and an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.) are added to recover the organic layer. To obtain a compound represented by the following general formula (b1-15-03).

［式中、Ｒ^２”、Ｒ^３”は前記と同じであり；Ｒ^０１”は前記一般式（ｂ１−１）中のＲ^１”のうち、置換基以外から１つの水素原子を除いた基であり；Ｂ⁻は有機酸のアニオン部である。］

[Wherein, R ² ″ and R ³ ″ are the same as above; R ⁰¹ ″ is a group obtained by removing one hydrogen atom from other than the substituent among R ¹ ″ in the general formula (b1-1). B ⁻ is the anion part of the organic acid. ]

^Wherein, R 2 ", ^{R 3"} is, ^R 2 in the general formula (b1-1) ", ^{R 3"} are the same as.
R ⁰¹ ″ is a group obtained by removing one hydrogen atom from other than the substituent among R ¹ ″ in the general formula (b1-1). For example, when R ¹ ″ is an aryl group, ⁰¹ ″ is an arylene group, and when R ¹ ″ is an alkyl group, R ⁰¹ ″ is an alkylene group.

  Next, the compound represented by the general formula (b1-15-03) is added to an organic solvent (for example, acetonitrile, dichloromethane, tetrahydrofuran, etc.) and stirred, and in the presence of a basic catalyst such as potassium carbonate, the following The compound represented by the general formula (b1-0-1) is added and reacted, followed by liquid separation and washing with water, and then the compound represented by the following general formula (b1-15-04) is obtained from the organic layer.

［式中、Ｒ^２”、Ｒ^３”、 Ｒ^０１”、Ｂ⁻、Ｗは前記と同じであり；Ｈａはハロゲン原子を表し；Ｈａ⁻はハロゲンイオンを表す。］

[Wherein, R ² ″, R ³ ″, R ⁰¹ ″, B ⁻ and W are the same as described above; Ha represents a halogen atom; Ha ⁻ represents a halogen ion.]

In the above formula, R ² ″, R ³ ″, R ⁰¹ ″ and B ⁻ are the same as described above, and W is the same as W in the general formula (b1-1-0).
Ha represents a halogen atom, and Ha ⁻ represents a halogen ion.
In the general formula (b1-15-04), the group represented by “—R ⁰¹ ” —O—W—O—CH═CH ₂ ”represents one hydrogen in the general formula (b1-1). This is the same as “—R ¹ ” in which the atom is substituted with the group represented by the general formula (b1-1-0).

The compound represented by the general formula (b1-15-04) is a mixture of a compound having an anion part (B ⁻ ) of an organic acid and a compound having a halogen ion (Ha ⁻ ) in the anion part.

The compound (b0-1) and the compound (b0-2) are reacted, for example, by dissolving these compounds in a solvent such as water, dichloromethane, acetonitrile, methanol, chloroform, methylene chloride, and the like. Can do.
The reaction temperature is preferably about 0 ° C to 150 ° C, more preferably about 0 ° C to 100 ° C. The reaction time varies depending on the reactivity of the compound (b0-1) and the compound (b0-2), the reaction temperature, and the like, but usually 0.5 to 10 hours is preferable, and 1 to 5 hours is more preferable.
The amount of compound (b0-2) used in the above reaction is usually preferably about 0.5 to 2 mol per 1 mol of compound (b0-1).
After completion of the reaction, the compound represented by the general formula (b1-1) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography and the like can be used alone or in combination of two or more.

The structure of the compound obtained as described above includes ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method, mass spectrometry (MS ) Method, elemental analysis method, X-ray crystal diffraction method, etc.

The compound of the present invention described above is a novel compound useful as an acid generator for a resist composition, and can be blended in a resist composition as an acid generator.
In the compound of the present invention, for example, a perfluoroalkylene group having 6 to 10 carbon atoms is hardly decomposable, whereas a fluorinated alkylene group of “— (CF ₂ ) _p ” in the anion portion is decomposable. Therefore, it is possible to obtain an effect that it is safer in terms of handling in consideration of bioaccumulation.

≪Acid generator≫
The acid generator which is the 4th aspect of this invention consists of a compound represented by the said general formula (b1-1).
The acid generator is useful as an acid generator for a chemically amplified resist composition, for example, the acid generator component (B) of the resist composition according to the first aspect of the present invention.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.

<Synthesis of novel compounds>
(Examples 1-2)
Novel compounds (B1-1) to (B1-2) were respectively synthesized according to the following synthesis examples.

[Synthesis Example 1: Synthesis Example of Compound (1)]

Phosphorus oxide (8.53 g), 2,6-dimethylphenol (8.81 g) and diphenyl sulfoxide (12.2 g) were added in small portions to methanesulfonic acid (60.75 g) controlled at 20 ° C. or lower. After aging for 30 minutes while controlling the temperature at 15 to 20 ° C., the temperature was raised to 40 ° C. and aging was performed for 2 hours. Then, the reaction liquid was dripped at the pure water (109.35g) cooled to 15 degrees C or less. After completion of the dropwise addition, dichloromethane (54.68 g) was added, and after stirring, the dichloromethane layer was recovered. In a separate container, hexane (386.86 g) at 20 to 25 ° C. was charged, and the dichloromethane layer was added dropwise. After completion of the dropwise addition, the mixture was aged at 20 to 25 ° C. for 30 minutes, and then filtered to obtain the target intermediate compound (1) (yield 70.9%).
The obtained compound (1) was analyzed by ¹ H-NMR.
¹ H-NMR (DMSO-d6, 600 MHz): δ (ppm) = 7.61-7.72 (m, 10H, phenyl), 7.14 (S, 2H, H ^c ), 3.12 (S, 3H, H ^b ), 2.22 (s, 6H, H ^a ).
From the results described above, it was confirmed that the obtained compound (1) had a structure shown below.

[Synthesis Example 2: Synthesis Example of Compound (2)]
Under a nitrogen atmosphere, the compound (1) (10.65 g) and acetonitrile (106.46 g) were added to a three-necked flask and stirred. To this was added potassium carbonate (18.28 g), and the mixture was stirred at room temperature for 10 minutes, and then 2-chloroethyl vinyl ether (32.1 g) was added dropwise. Thereafter, the temperature was raised to 80 ° C. and stirred for 72 hours. The reaction solution was cooled to room temperature and then filtered, and the filtrate was concentrated and dried with a rotary evaporator. The obtained oil product was dissolved in water (52.47 g) and washed three times with hexane (52.47 g). Further, extraction with dichloromethane (159.69 g) was performed, and the organic solvent layer was washed three times with water (52.47 g). After the washing, the organic solvent layer was concentrated and dried to obtain 5.6 g of the target precursor compound (2).
The obtained compound (2) was analyzed by NMR.
¹ H-NMR (CDCl ₃ , 400 MHz): δ (ppm) = 7.69-7.81 (m, 10H, Ar), 7.46 (s, 2H, Ar), 6.49-6.55 ( _{m, 1H Vinyl), 4.02-4.27 (} m, 6H ,, CH 2 + Vinyl), 2.75 (s, 3H, CH 3 SO 3), 2.36 (s, 6H, CH 3)
Further, from the results of ion chromatography, the mixture ratio of CH ₃ SO ₃ body and Cl body having different anion parts is a mixture of CH ₃ SO ₃ : Cl = 73.4: 26.6 (mol ratio). all right.
From the results described above, it was confirmed that the obtained compound (2) had a structure shown below.

[Example 1: Synthesis example of compound (B1-1)]
(I) Synthesis Example of Compound (3) 16.7 ml of tetrahydrofuran was added to 5.0 g of 2-naphthylmethyloxytetrafluoroethanesulfonyl fluoride, and 0.98 g of water was added to the solution in an ice bath. An aqueous solution in which lithium oxide was dissolved in 13.6 ml of pure water was added dropwise. Then, it stirred in the ice bath. It was confirmed that all of the fluorinated sulfonyl groups were converted to lithium sulfonate due to the absence of ¹⁹ F-NMR absorption at −217.6 ppm by —SO ₂ F.
Thereafter, the reaction solution was concentrated and dried to obtain a white viscous solid. The obtained crude product is dissolved in 14.2 ml of acetone, filtered to remove the by-product LiF, and the filtrate is concentrated to obtain 5.50 g of the precursor compound (3). It was.

(Ii) Synthesis Example of Compound (B1-1) Compound (2) (2 g) was added to dichloromethane (20 g) and water (20 g) and stirred. Furthermore, compound (3) (1.87 g) was added and stirred for 1 hour. After separating the reaction solution, it was washed 4 times with water (20 g). After washing, the organic solvent layer was concentrated to dryness to obtain 2.4 g of compound (B1-1).
The obtained compound (B1-1) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.51-7.96 (m, 17H, Ar), 7.46 (s, 2H, Ar), 6.49-6.55 _{(m, 1H Vinyl), 5.20} (s, 2H, CH 2), 4.02-4.27 (m, 6H ,, CH 2 + Vinyl), 2.36 (s, 6H, CH 3)
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 80.5, −113.7
From the results shown above, it was confirmed that the obtained compound (B1-1) had a structure shown below.

[Example 2: Synthesis example of compound (B1-2)]
(I) Synthesis Example of Compound (4) 142.35 g of diglyme was added to 28.57 g of silver fluoride, cooled to 0 ° C., and 40.55 g of tetrafluoro-1,2-oxathietane-2,2-dioxide was added dropwise. After stirring at room temperature for 1 hour, the system was cooled again to 0 ° C. There, the diglyme (99.88g) solution of 1-bromoadamantane 49.94g was dripped, and it stirred at room temperature for 14 hours. Thereto, 508 ml of hexane was added, and the inside of the system was cooled to 0 ° C. After 127 ml of water was added dropwise at 0 ° C., the mixture was stirred for 10 minutes. The insoluble material was filtered off, and the filtrate was separated. The obtained organic layer was washed with 169 ml of saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. 254 ml of hexane was added to the residue, the precipitated crystals were filtered off, and the filtrate was concentrated under reduced pressure to obtain 23.30 g of 1-adamantoxytetrafluoroethanesulfonyl fluoride (Compound A) (yield: 30). %).

Compound A was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 2.19 (s, 3H, adamantane), 2.05 (s, 6H, adamantane), 1.62 (s, 6H, adamantane).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 69.96, −108.05.
From the results described above, it was confirmed that the compound A had a structure shown below.

  Next, 16.7 ml of tetrahydrofuran was added to 10 g of 1-adamantoxytetrafluoroethanesulfonyl fluoride (Compound A), and 0.64 g of lithium hydroxide was added to the solution in 13.6 ml of pure water in an ice bath. An aqueous solution dissolved in was dropped. Then, it stirred in the ice bath. Thereafter, the reaction solution is filtered to remove LiF, and then the filtrate is washed with 33.4 ml of t-butyl methyl ether and separated to recover an aqueous solution, whereby a 32 mass% aqueous solution of compound (4) is recovered. Obtained (yield: 70%).

Compound (4) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 2.33 (s, 3H, adamantane), 2.21 (s, 6H, adamantane), 1.80 (s, 6H, adamantane).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 70.37, −113.70.
From the results shown above, it was confirmed that the compound (4) had a structure shown below.

(Ii) Synthesis Example of Compound (B1-2) Compound (2) (2 g) was added to dichloromethane (20 g) and water (20 g) and stirred. Further, compound (4) (1.84 g) was added and stirred for 1 hour. After separating the reaction solution, it was washed 4 times with water (20 g). After washing, the organic solvent layer was concentrated and dried to obtain 2.3 g of compound (B1-2).
The obtained compound (B1-2) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.69-7.81 (m, 10H, Ar), 7.46 (s, 2H, Ar), 6.49-6.55 (M, 1H Vinyl), 4.02-4.27 (m, 6H, CH ₂ + Vinyl), 2.36 (s, 6H, CH ₃ ), 2.09 (s, 3H, adamantane), 1. 96 (s, 6H, adamantane), 1.56 (s, 6H, adamantane)
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 70.13, −113.36
From the results shown above, it was confirmed that the obtained compound (B1-2) had a structure shown below.

<Preparation of resist composition>
(Examples 3 to 4, Comparative Example 1)
Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition.

In Table 1, each abbreviation indicates the following, and the numerical value in [] is the blending amount (part by mass).
(A) -1: a copolymer represented by the following chemical formula (A1-11-1), Mw10000, Mw / Mn1.5. In the formula, the numerical value on the lower right of () indicates the ratio (mol%) of each structural unit.

(B) -1: Compound (B1-1).
(B) -2: the compound (B1-2).
(B) -3: (4-methylphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate.
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: PGMEA / PGME = 6/4 (mass ratio) mixed solvent.
(S) -2: γ-butyrolactone.

<Evaluation of lithography properties>
Using the obtained resist composition, a resist pattern was formed by the following procedure, and the lithography characteristics were evaluated.
[Resist pattern formation]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked at 205 ° C. for 60 seconds on a hot plate and dried. Thus, an organic antireflection film having a film thickness of 82 nm was formed.
Then, the resist composition is applied onto the antireflection film using a spinner, prebaked (PAB) at 110 ° C. for 60 seconds on a hot plate, and dried to have a film thickness of 150 nm. The resist film was formed.
Next, an ArF excimer laser (193 nm) is applied to the resist film by using an ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination) as a mask pattern. Irradiated selectively through (6% halftone mask).
Then, a post-exposure heating (PEB) treatment was performed at 110 ° C. for 60 seconds, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution NMD-3 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. ) For 30 seconds, followed by alkaline rinsing with pure water for 30 seconds, followed by shaking off and drying.
As a result, in each example, a line and space pattern (hereinafter referred to as “L / S pattern”) having a line width of 120 nm and a pitch of 240 nm was formed on the resist film.

[sensitivity]
In the above resist pattern formation, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming an L / S pattern having a line width of 120 nm and a pitch of 240 nm was determined. The results are shown in Table 1.

[Evaluation of resist pattern shape]
About the L / S pattern obtained by said resist pattern formation, the resist pattern shape was observed from the sky using the scanning electron microscope (SEM).
As a result, it was confirmed that the L / S patterns of Example 3 and Example 4 were both good shapes with less surface roughness and line edge roughness than the L / S pattern of Comparative Example 1.

Claims (9)

A resist composition containing a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure,
The said acid generator component (B) contains the acid generator (B1) which consists of a compound represented by the following general formula (b1-1), The resist composition characterized by the above-mentioned.

[In formula (b1-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent, and at least one of R ¹ ″ to R ³ ″ is , A substituted aryl group in which some of the hydrogen atoms are substituted with a group represented by the following general formula (b1-1-0), and any two of R ¹ ″ to R ³ ″ are bonded to each other. A ring may be formed together with the sulfur atom in the formula. X is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ² is a single bond or an alkylene group, and p is an integer of 1 to 3. ]

[In Formula (b1-1-0), W represents a linear or branched alkylene group having 2 to 10 carbon atoms. ]   The resist composition according to claim 1, wherein the base material component (A) is a base material component whose solubility in an alkaline developer is increased by the action of an acid. The base component (A) is a structural unit derived from an acrylate ester which may have a substituent bonded to the α-position carbon atom, and a structural unit (a1) containing an acid dissociable, dissolution inhibiting group. The resist composition of Claim 2 containing the resin component (A1) which has. The resin component (A1) further includes a structural unit (a2) that is a structural unit derived from an acrylate ester in which a substituent may be bonded to the α-position carbon atom and includes a lactone-containing cyclic group. The resist composition according to claim 3. The resin component (A1) is further a structural unit derived from an acrylate ester in which a substituent may be bonded to a carbon atom at the α-position, and containing a polar group-containing aliphatic hydrocarbon group ( The resist composition according to claim 3 or 4, which has a3).
  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 the support using the resist composition according to any one of claims 1 to 6, a step of exposing the resist film, and an alkali developing of the resist film to form a resist pattern A resist pattern forming method including a step of forming a film. The compound represented by the following general formula (b1-1).

[In formula (b1-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent, and at least one of R ¹ ″ to R ³ ″ is , A substituted aryl group in which some of the hydrogen atoms are substituted with a group represented by the following general formula (b1-1-0), and any two of R ¹ ″ to R ³ ″ are bonded to each other. A ring may be formed together with the sulfur atom in the formula. X is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ² is a single bond or an alkylene group, and p is an integer of 1 to 3. ]

[In Formula (b1-1-0), W represents a linear or branched alkylene group having 2 to 10 carbon atoms. ]   An acid generator comprising the compound according to claim 8.