JP6454760B2 - Resist composition and resist pattern forming method - Google Patents

Description

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

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed and developed to form a resist pattern having a predetermined shape on the resist film. The process to perform is performed. A resist material in which the exposed portion of the resist film 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 exposure light source is generally shortened in wavelength (increased energy). 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. Further, studies have been made on EUV (extreme ultraviolet), EB (electron beam), X-rays and the like having shorter wavelengths (higher energy) 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.
Conventionally, as a resist material satisfying such requirements, there is a chemically amplified resist composition containing a base material component whose solubility in a developing solution is changed by the action of an acid and an acid generator component that generates an acid upon exposure. It is used.
For example, when the developer is an alkali developer (alkaline development process), the positive chemically amplified resist composition includes a resin component (base resin) whose solubility in an alkali developer is increased by the action of an acid, an acid Those containing a generator component are generally used. 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 acid generator component in the exposed portion, and the polarity of the base resin increases due to the action of the acid. Thus, the exposed portion becomes soluble in the alkaline developer. Therefore, by performing alkali development, a positive pattern in which an unexposed portion remains as a pattern is formed.
On the other hand, when such a chemically amplified resist composition is applied to a solvent development process using a developer containing an organic solvent (organic developer), the organic development is relatively increased when the polarity of the base resin increases. Since the solubility in the solution is lowered, the unexposed portion of the resist film is dissolved and removed by the organic developer, and a negative resist pattern in which the exposed portion remains as a pattern is formed. Such a solvent development process for forming a negative resist pattern is sometimes referred to as a negative development process (see, for example, Patent Document 1).

The base resin used in the chemically amplified resist composition generally has a plurality of structural units for improving lithography properties and the like.
For example, in the case of a resin component whose solubility in an alkaline developer is increased by the action of an acid, a structural unit containing an acid-decomposable group that is decomposed by the action of an acid generated from an acid generator or the like and increases in polarity is used. In addition, a structural unit containing a lactone-containing cyclic group, a structural unit containing a polar group such as a hydroxyl group, and the like are used in combination (for example, see Patent Document 2).
In recent years, with the progress of pattern miniaturization, the demand for a polymer compound useful as a base resin for a resist composition is increasing.
Among them, for example, a polymer compound using, as a monomer, a polycyclic ester containing an electron-withdrawing substituent and a lactone skeleton, and a resist composition containing this polymer compound have been proposed (see Patent Document 3). ).

JP 2009-025723 A JP 2003-241385 A JP 2008-231059 A

Along with further advancement of lithography technology and expansion of application fields, in resist pattern formation, further improvement of various lithography properties such as high sensitivity and improvement of roughness is required. However, for example, in the resist composition described in Patent Document 3, further improvement of the roughness of the resist pattern is required.
This invention is made | formed in view of the said situation, and makes it a subject the resist composition which can form the resist pattern with reduced roughness.

  A first aspect of the present invention that solves the above problems includes a step of forming a resist film on a support using a resist composition, a step of exposing the resist film, and a step of exposing the resist film after the exposure to an alkaline developer. A positive resist composition used in a resist pattern forming method including a step of forming a positive resist pattern by developing with an acid, which generates an acid upon exposure and changes its solubility in a developer due to the action of the acid. A base material component (A) whose solubility in an alkaline developer is increased by the action of an acid, an acid generator component (B) that generates an acid upon exposure, and the following general formula (d1- 1 or more compounds (D1) selected from the group consisting of the compound represented by 1), the compound represented by the general formula (d1-2), and the compound represented by the general formula (d1-3); Contains The base component (A) includes a polymer compound (A1) having a structural unit (a0) represented by the following general formula (a0-1), and the acid generator component (B) and the compound ( The resist composition is characterized in that a molar ratio represented by (D1) / (B) indicating a mixing ratio with D1) is 0.5 or more.

［式中、Ｒｄ^１〜Ｒｄ^４は置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、又は置換基を有していてもよい鎖状のアルケニル基である。但し、式（ｄ１−２）中のＲｄ^２における、Ｓ原子に隣接する炭素原子にはフッ素原子は結合していないものとする。Ｙｄ^１は単結合又は２価の連結基である。ｍは１以上の整数であって、Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

[Wherein Rd ^{1 to} Rd ⁴ are a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain which may have a substituent. Of the alkenyl group. However, a fluorine atom is not bonded to a carbon atom adjacent to the S atom in Rd ² in the formula (d1-2). Yd ¹ is a single bond or a divalent linking group. m is an integer of 1 or more, and M ^{m +} is each independently an m-valent organic cation. ]

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｖａ^０は置換基を有していてもよい２価の炭化水素基である。ｎ_ａ0は０〜２の整数である。Ｒａ^１及びＲａ^２は、それぞれ独立に水素原子、炭素数１〜５のアルキル基、アルコキシ基、若しくはアルキルチオ基であるか、又は、Ｒａ^１とＲａ^２とが互いに結合し、酸素原子（−Ｏ−）若しくは硫黄原子（−Ｓ−）を含んでいてもよい炭素数１〜６のアルキレン基、エーテル結合、若しくはチオエーテル結合となってもよい。Ｒａ’^０１はハロゲン原子を有していてもよい炭素数１〜６のアルキル基、ヒドロキシ基部分が保護基で保護されていてもよく且つハロゲン原子を有していてもよい炭素数１〜６のヒドロキシアルキル基、塩を形成しているカルボキシ基、又は置換オキシカルボニル基である。２つ以上のＲａ’^０１が存在する場合、複数のＲａ’^０１は互いに同じであっても異なっていてもよい。Ｘはハロゲン原子、カルボキシ基、アシル基、ニトロ基及びシアノ基からなる群より選択される置換基である。２つ以上のＸが存在する場合、複数のＸは互いに同じであっても異なっていてもよい。ｐ_０は０〜８の整数である。ｑ_０は１〜９の整数である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Va ⁰ is a divalent hydrocarbon group which may have a substituent. n _a0 is an integer of 0-2. Ra ¹ and Ra ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or an alkylthio group, or Ra ¹ and Ra ² are bonded to each other to form an oxygen atom (—O -) Or a C1-C6 alkylene group which may contain a sulfur atom (-S-), an ether bond, or a thioether bond. Ra ′ ⁰¹ may have a halogen atom, an alkyl group having 1 to 6 carbon atoms, and the hydroxy group portion may be protected with a protecting group and may have a halogen atom. A hydroxyalkyl group, a carboxy group forming a salt, or a substituted oxycarbonyl group. When two or more Ra ′ ⁰¹ are present, the plurality of Ra ′ ⁰¹ may be the same as or different from each other. X is a substituent selected from the group consisting of a halogen atom, a carboxy group, an acyl group, a nitro group, and a cyano group. When two or more X are present, the plurality of X may be the same as or different from each other. p ₀ is an integer of 0-8. q ₀ is an integer of 1 to 9. ]

  The second aspect of the present invention includes a step of forming a resist film on a support using the resist composition of the first aspect of the present invention, a step of exposing the resist film, and a resist film after the exposure And a step of forming a positive resist pattern by developing with an alkaline developer.

  According to the resist composition and the resist pattern forming method of the present invention, a resist pattern with reduced roughness can be formed.

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which part or all of the hydrogen atoms of an alkyl group or alkylene group are substituted with fluorine atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
When it is described as “may have a substituent”, when a hydrogen atom (—H) is substituted with a monovalent group, and when a methylene group (—CH ₂ —) is substituted with a divalent group And both.
“Exposure” is a concept including general irradiation of radiation.

“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid ester” is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
In the acrylate ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent (R ^α0 ) for substituting the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom, such as an alkyl group having 1 to 5 carbon atoms or a halogenated group having 1 to 5 carbon atoms. An alkyl group etc. are mentioned. In addition, itaconic acid diesters in which the substituent (R ^α0 ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R ^α0 ) is substituted with a hydroxyalkyl group or a group with a modified hydroxyl group thereof Shall be included. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group of acrylic acid is bonded unless otherwise specified.
Hereinafter, an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylate ester. Further, the acrylate ester and the α-substituted acrylate ester may be collectively referred to as “(α-substituted) acrylate ester”.

“Structural unit derived from acrylamide” means a structural unit formed by cleavage of the ethylenic double bond of acrylamide.
In acrylamide, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and one or both of the hydrogen atoms of the amino group of acrylamide may be substituted with a substituent. The α-position carbon atom of acrylamide is a carbon atom to which the carbonyl group of acrylamide is bonded unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom bonded to the α-position carbon atom of acrylamide are the same as those described as the α-position substituent (substituent (R ^α0 )) in the α-substituted acrylic ester. Can be mentioned.

“A structural unit derived from hydroxystyrene or a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
“Hydroxystyrene derivative” is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. These derivatives include those in which the hydrogen atom of the hydroxy styrene of the hydroxystyrene which may be substituted with a substituent at the α-position is substituted with an organic group; the hydrogen atom at the α-position is substituted with a substituent The thing etc. which the substituents other than a hydroxyl group couple | bonded with the benzene ring of good hydroxystyrene are mentioned. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents as those mentioned as the substituent at the α-position in the α-substituted acrylic ester.

The “structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative” means a structural unit configured by cleavage of an ethylenic double bond of vinyl benzoic acid or a vinyl benzoic acid derivative.
The “vinyl benzoic acid derivative” is a concept including a compound in which the hydrogen atom at the α-position of vinyl benzoic acid is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. These derivatives include those in which the hydrogen atom at the carboxy group of vinyl benzoic acid, which may be substituted with a hydrogen atom at the α-position, is substituted with an organic group; the hydrogen atom at the α-position is substituted with a substituent. Examples thereof include those in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinyl benzoic acid. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.

“Styrene” is a concept that includes styrene and those in which the α-position hydrogen atom of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.
“Structural unit derived from styrene” and “structural unit derived from styrene derivative” mean a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.

The alkyl group as a substituent at the α-position is preferably a linear or branched alkyl group, specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group). , N-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
Specific examples of the halogenated alkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” are substituted with a halogen atom. It is done. 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.
Specific examples of the hydroxyalkyl group as a substituent at the α-position include a group in which part or all of the hydrogen atoms of the “alkyl group as the substituent at the α-position” are substituted with a hydroxyl group. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.

≪Resist composition≫
The resist composition of the first aspect of the present invention is a resist composition that generates an acid upon exposure and changes its solubility in a developer due to the action of an acid, and the solubility in a developer changes due to the action of an acid. Base component (A) (hereinafter also referred to as “(A) component”), an acid generator component (B) that generates acid upon exposure (hereinafter also referred to as “(B) component”), and a general formula One or more compounds (D1) selected from the group consisting of a compound represented by (d1-1), a compound represented by General Formula (d1-2), and a compound represented by General Formula (d1-3) (Hereinafter also referred to as “component (D1)”).
When a resist film is formed using such a resist composition and the resist film is selectively exposed, an acid is generated in the exposed portion, and the action of the acid causes the solubility of the component (A) in the developer. On the other hand, since the solubility of the component (A) in the developer does not change in the unexposed area, a difference in solubility in the developer occurs between the exposed area and the unexposed area. Therefore, when the resist film is developed, when the resist composition is positive, the exposed portion is dissolved and removed to form a positive resist pattern, and when the resist composition is negative, the unexposed portion is dissolved. This is removed to form a negative resist pattern.
In this specification, a resist composition in which an exposed portion is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and an unexposed portion is dissolved and removed to form a negative resist pattern. Is referred to as a negative resist composition.
The resist composition of this embodiment may be a positive resist composition or a negative resist composition.
Further, the resist composition of this embodiment may be used for an alkali development process using an alkali developer for the development process at the time of forming a resist pattern, and a developer (organic developer) containing an organic solvent is used for the development process. It may be for the solvent development process used.

<(A) component>
In the present invention, the “base component” is an organic compound having a film forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved, and in addition, a nano-level resist pattern is easily formed.
Organic compounds used as the base material component are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the “low molecular compound” refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, those having a molecular weight of 1000 or more are usually used. Hereinafter, the term “resin” or “polymer compound” refers to a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used.

When the resist composition of this embodiment is a “negative resist composition for an alkali development process” that forms a negative resist pattern in an alkali development process, or “solvent development” that forms a positive resist pattern in a solvent development process In the case of “a positive resist composition for a process”, the component (A) is preferably a substrate component (A-2) (hereinafter referred to as “(A-2) component”) soluble in an alkali developer. In addition, a crosslinking agent component is blended. In such a resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause crosslinking between the component (A-2) and the crosslinking agent component. Solubility decreases (solubility in organic developer increases). Therefore, in the formation of a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed, the exposed portion is hardly soluble in an alkali developer (to an organic developer). On the other hand, the unexposed area remains soluble (almost insoluble in the organic developer) while remaining undissolved in the alkaline developer, and a negative resist pattern is formed by developing with the alkaline developer. The At this time, a positive resist pattern is formed by developing with an organic developer.
As the component (A-2), a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”) is used.
Examples of the alkali-soluble resin include α- (hydroxyalkyl) acrylic acid or α- (hydroxyalkyl) acrylic acid alkyl ester (preferably having 1 to 5 carbon atoms) disclosed in, for example, JP-A-2000-206694. A resin having a unit derived from at least one selected from alkyl ester); a hydrogen atom bonded to a carbon atom at the α-position having a sulfonamide group, which is disclosed in US Pat. No. 6,949,325, is substituted with a substituent. Acrylic resin or polycycloolefin resin which may be contained; disclosed in US Pat. No. 6,949,325, Japanese Patent Application Laid-Open No. 2005-336452, and Japanese Patent Application Laid-Open No. 2006-317803, which contains a fluorinated alcohol and is in the α-position. The hydrogen atom bonded to the atom may be substituted with a substituent. Le resin; Japanese Patent disclosed in 2006-259582, JP-polycycloolefin resins having fluorinated alcohol is preferred because it can form a resist pattern with minimal swelling.
The α- (hydroxyalkyl) acrylic acid is a hydrogen atom bonded to the α-position carbon atom to which the carboxy group is bonded, among the acrylic acid in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. One or both of acrylic acid having an atom bonded thereto and α-hydroxyalkylacrylic acid having a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) bonded to the α-position carbon atom are shown. .
As the crosslinking agent component, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, a melamine crosslinking agent, and the like because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent component is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of this embodiment is a “positive resist composition for an alkali development process” that forms a positive resist pattern in an alkali development process, or “solvent development” that forms a negative resist pattern in a solvent development process In the case of “a negative resist composition for process”, the component (A) is preferably a base material component (A-1) whose polarity is increased by the action of an acid (hereinafter referred to as “(A-1) component”). ) Is used. By using the component (A-1), since the polarity of the base material component changes before and after exposure, a good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
When an alkali development process is applied, the component (A-1) is hardly soluble in an alkali developer before exposure. When an acid is generated by exposure, the polarity is increased by the action of the acid, and the alkali development is performed. The solubility in the liquid is increased. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion changes from slightly soluble to soluble in an alkaline developer. Since the unexposed portion remains hardly soluble in alkali and does not change, a positive resist pattern is formed by alkali development.
On the other hand, when a solvent development process is applied, the component (A-1) is highly soluble in an organic developer before exposure. When an acid is generated by exposure, the component (A-1) is highly polar due to the action of the acid. The solubility in an organic developer is reduced. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the resist composition on the support is selectively exposed, the exposed portion changes from soluble to poorly soluble in an organic developer. On the other hand, since the unexposed portion remains soluble and does not change, development with an organic developer can provide a contrast between the exposed portion and the unexposed portion, thereby forming a negative resist pattern.

The component (A) used in the resist composition of this embodiment is a polymer compound (A1) having the structural unit (a0) represented by the general formula (a0-1) (hereinafter referred to as “component (A1)”). Is included.
As the component (A), at least the component (A1) is used, and other high molecular compounds and / or low molecular compounds may be used in combination with the component (A1).
In the resist composition of this embodiment, the component (A) is preferably the component (A-1). That is, the resist composition of this embodiment is a “positive resist composition for an alkali development process” that forms a positive resist pattern in an alkali development process, or a “solvent development process that forms a negative resist pattern in a solvent development process. The negative resist composition for use is preferable. In addition, the component (A-1) preferably contains the component (A1).

[(A1) component]
The component (A1) is a polymer compound having the structural unit (a0) represented by the general formula (a0-1).

(Structural unit (a0))
The structural unit (a0) is a structural unit represented by the following general formula (a0-1). In forming a resist pattern, using a polymer compound having the structural unit (a0) as a base resin is effective for increasing sensitivity.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｖａ^０は置換基を有していてもよい２価の炭化水素基である。ｎ_ａ0は０〜２の整数である。Ｒａ^１及びＲａ^２は、それぞれ独立に水素原子、炭素数１〜５のアルキル基、アルコキシ基、若しくはアルキルチオ基であるか、又は、Ｒａ^１とＲａ^２とが互いに結合し、酸素原子（−Ｏ−）若しくは硫黄原子（−Ｓ−）を含んでいてもよい炭素数１〜６のアルキレン基、エーテル結合、若しくはチオエーテル結合となってもよい。Ｒａ’^０１はハロゲン原子を有していてもよい炭素数１〜６のアルキル基、ヒドロキシ基部分が保護基で保護されていてもよく且つハロゲン原子を有していてもよい炭素数１〜６のヒドロキシアルキル基、塩を形成しているカルボキシ基、又は置換オキシカルボニル基である。２つ以上のＲａ’^０１が存在する場合、複数のＲａ’^０１は互いに同じであっても異なっていてもよい。Ｘはハロゲン原子、カルボキシ基、アルコキシカルボニル基、アシル基、ニトロ基及びシアノ基からなる群より選択される置換基である。２つ以上のＸが存在する場合、複数のＸは互いに同じであっても異なっていてもよい。ｐ_０は０〜８の整数である。ｑ_０は１〜９の整数である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Va ⁰ is a divalent hydrocarbon group which may have a substituent. n _a0 is an integer of 0-2. Ra ¹ and Ra ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or an alkylthio group, or Ra ¹ and Ra ² are bonded to each other to form an oxygen atom (—O -) Or a C1-C6 alkylene group which may contain a sulfur atom (-S-), an ether bond, or a thioether bond. Ra ′ ⁰¹ may have a halogen atom, an alkyl group having 1 to 6 carbon atoms, and the hydroxy group portion may be protected with a protecting group and may have a halogen atom. A hydroxyalkyl group, a carboxy group forming a salt, or a substituted oxycarbonyl group. When two or more Ra ′ ⁰¹ are present, the plurality of Ra ′ ⁰¹ may be the same as or different from each other. X is a substituent selected from the group consisting of a halogen atom, a carboxy group, an alkoxycarbonyl group, an acyl group, a nitro group, and a cyano group. When two or more X are present, the plurality of X may be the same as or different from each other. p ₀ is an integer of 0-8. q ₀ is an integer of 1 to 9. ]

In the formula (a0-1), the alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group or an ethyl group. Propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
The halogenated alkyl group having 1 to 5 carbon atoms is a group in which part or all of the hydrogen atoms of the aforementioned “alkyl group having 1 to 5 carbon atoms in R” are substituted with a halogen atom. 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.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is particularly preferable from the viewpoint of industrial availability.

In the formula (a0-1), Va ⁰ is a divalent hydrocarbon group which may have a substituent.
The hydrocarbon group for Va ⁰ 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 as a divalent hydrocarbon group in Va ⁰ may be saturated or unsaturated, and is usually preferably saturated.
More specifically, examples of the aliphatic hydrocarbon group for Va ⁰ include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group having a ring in the structure.
Va ⁰ may have a substituent. A methylene group in the hydrocarbon group Va ⁰ (-CH ₂ -) as if is substituted by a divalent group, an ether bond between the divalent carbon atoms of the hydrocarbon group Va ⁰ (-O-) The thing which has is mentioned. In this case, ether bonds present in Va ⁰ may be even one or two or more. Further, as a case where a hydrogen atom in the hydrocarbon group Va ⁰ (-H) is substituted by a monovalent group, a hydrogen atom (-H) number fluorine atom or a carbon in the hydrocarbon group Va ⁰ 1 to 5 And those substituted with a fluorinated alkyl group. As Va ^{0 in} this case, —CH ₂ CHF—, —CH (CH ₂ CH ₃ ) CF ₂ —, —CH (CH ₂ CH ₃ ) C (CF ₃ ) F—, —CH (CH ₃ ) CF ₂ -Etc. are preferable.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, more preferably 1 to 4, and most preferably 1 to 3.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
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 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene 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 alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

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

The aromatic hydrocarbon group for Va ⁰ is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, 5-20 are more preferable, 6-15 are more preferable, and 6-12 are especially preferable. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms, and the like. Can be mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings A group obtained by removing two hydrogen atoms from (for example, biphenyl, fluorene, etc.); 1 of the hydrogen atoms of a group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring A group substituted with an alkylene group (for example, an aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) A group in which one atom is further removed). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

In the formula (a0-1), _na0 is an integer of ₀ to 2, preferably 0 or 1, and more preferably 0.

In the formula (a0-1), Ra ¹ and Ra ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or an alkylthio group, or Ra ¹ and Ra ² are They may be bonded to each other to form an alkylene group having 1 to 6 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—), an ether bond, or a thioether bond.
The alkyl group having 1 to 5 carbon atoms in Ra ¹ and Ra ² is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, and isopropyl. Group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
The alkoxy group in Ra ¹ and Ra ² is preferably linear or branched, and specifically, the alkyl group and oxygen atom (—O—) mentioned as the alkyl group in Ra ¹ and Ra ² above. And a group in which and are linked.
The alkylthio group in Ra ¹ and Ra ² preferably has 1 to 4 carbon atoms, and specifically includes a methylthio group, an ethylthio group, an n-propylthio group, an iso-propylthio group, an n-butylthio group, and a tert-butylthio group. Is mentioned.
Also, Ra ¹ and Ra ² are, Ra ¹ and Ra ² and are bonded to each other, an oxygen atom (-O-) or a sulfur atom (-S-) a comprise also an alkylene group having 1 to 6 carbon atoms, It may be an ether bond (—O—) or a thioether bond (—S—).
The alkylene group having 1 to 6 carbon atoms formed by combining Ra ¹ and Ra ² with each other is preferably a linear or branched alkylene group, and includes a methylene group, an ethylene group, an n-propylene group, an iso group. A propylene group etc. are mentioned. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like. The group formed by combining Ra ¹ and Ra ² with each other is preferably an alkylene group having 1 to 6 carbon atoms or —O—, more preferably an alkylene group having 1 to 6 carbon atoms, and 1 to 5 carbon atoms. Are more preferable, and a methylene group is particularly preferable.

In the formula (a0-1), Ra ′ ⁰¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxy group part may be protected with a protecting group, and has a halogen atom. Or a hydroxyalkyl group having 1 to 6 carbon atoms, a carboxy group forming a salt, or a substituted oxycarbonyl group.

Examples of the alkyl group having 1 to 6 carbon atoms in Ra ′ ⁰¹ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, and pentyl. Group, a hexyl group, etc. are mentioned, Among these, a C1-C5 alkyl group is preferable, a C1-C4 alkyl group is more preferable, a C1-C3 alkyl group is further more preferable, a methyl group or An ethyl group is particularly preferred, and a methyl group is most preferred. Examples of the halogen atom that the alkyl group having 1 to 6 carbon atoms of Ra ′ ⁰¹ may have include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 6 carbon atoms having a halogen atom include a chloroalkyl group such as a chloromethyl group; a fluoroalkyl such as a trifluoromethyl group, a 2,2,2-trifluoroethyl group, and a pentafluoroethyl group And a group (preferably a fluoroalkyl group having 1 to 3 carbon atoms).

Examples of the hydroxyalkyl group having 1 to 6 carbon atoms in Ra ′ ⁰¹ include, for example, hydroxymethyl group, 2-hydroxyethyl group, 1-hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, 4-hydroxy A butyl group, 6-hydroxyhexyl group, etc. are mentioned. Ra ^'01 of, The halogen atom which may have a hydroxy alkyl group having 1 to 6 carbon atoms, for example fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a fluorine atom is preferable. Examples of the C1-C6 hydroxyalkyl group having a halogen atom include a difluorohydroxymethyl group, 1,1-difluoro-2-hydroxyethyl group, 2,2-difluoro-2-hydroxyethyl group, 1,1 2,2-tetrafluoro-2-hydroxyethyl group, and the like. Among the hydroxyalkyl groups having 1 to 6 carbon atoms which may have a halogen atom, hydroxyalkyl groups having 1 to 3 carbon atoms which may have a halogen atom are preferable, and 1 or 2 carbon atoms (preferably A hydroxyalkyl group having 1 carbon atom or a hydroxyalkyl group having a halogen atom having 1 or 2 carbon atoms (preferably 1 carbon atom) is more preferable.
Examples of the protecting group for protecting the hydroxy group part of the hydroxyalkyl group having 1 to 6 carbon atoms which may have a halogen atom include, for example, an ether bond with an oxygen atom constituting a hydroxy group such as a methyl group or a methoxymethyl group Or a group that forms an acetal bond; a group that forms an ester bond with an oxygen atom constituting a hydroxy group such as an acetyl group or a benzoyl group.

Examples of the carboxy group forming a salt in Ra ′ ⁰¹ (carboxy group salt) include alkali metal salts, alkaline earth metal salts, transition metal salts, and the like.

Examples of the substituted oxycarbonyl group in Ra ′ ⁰¹ include an alkoxycarbonyl group in which an alkoxy group having 1 to 4 carbon atoms and a carbonyl group are bonded (specifically, a methoxycarbonyl group, an ethoxycarbonyl group, an isopropyloxycarbonyl group). Alkyloxycarbonyl groups such as n-propoxycarbonyl group; alkenyloxycarbonyl groups such as vinyloxycarbonyl group and allyloxycarbonyl group); cycloalkyloxycarbonyl groups such as cyclohexyloxycarbonyl group and aryloxy such as phenyloxycarbonyl group A carbonyl group etc. are mentioned.

In the structural unit represented by the formula (a0-1), when two or more Ra ′ ⁰¹ are present, the plurality of Ra ′ ⁰¹ may be the same as or different from each other.

Ra ′ ⁰¹ may be a C 1-6 alkyl group which may have a halogen atom, a hydroxy group part may be protected with a protecting group, and may have a halogen atom. A good C1-C6 hydroxyalkyl group and substituted oxycarbonyl group are preferred.
Among the alkyl groups having 1 to 6 carbon atoms which may have a halogen atom, an alkyl group having 1 to 3 carbon atoms or a halogenated alkyl group having 1 to 3 carbon atoms is more preferable. A fluoromethyl group is particularly preferred.
Among the hydroxyalkyl groups having 1 to 6 carbon atoms in which the hydroxy group portion may be protected with a protecting group and may have a halogen atom, the hydroxy group portion may be protected with a protecting group A hydroxyalkyl group of 1 to 3 or a hydroxyalkyl group having a halogen atom that may be protected by a protecting group is preferred, and a hydroxymethyl group, the hydroxy group part is a protecting group such as an acetoxymethyl group. A hydroxymethyl group which may be protected is more preferred.

In the formula (a0-1), X is a substituent selected from the group consisting of a halogen atom, a carboxy group, an alkoxycarbonyl group, an acyl group, a nitro group, and a cyano group.
As a halogen atom in X, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example, A fluorine atom is preferable.
Examples of the alkoxycarbonyl group for X include a methoxycarbonyl group.
Examples of the acyl group for X include an acetyl group.
In the structural unit represented by the formula (a0-1), when two or more Xs are present, the plurality of Xs may be the same as or different from each other.
X is a halogen atom (preferably a fluorine atom), a carboxy group, an alkoxycarbonyl group (preferably a methoxycarbonyl group), an acyl group (preferably an acetyl group), among the above from the viewpoint of high electron withdrawing property, A cyano group and a nitro group are preferable, and a cyano group is particularly preferable.

In the formula (a0-1), p ₀ is an integer of ₀ to 8, preferably an integer of 0 to 6, and more preferably an integer of 0 to 3.
In the formula (a0-1), q ₀ is an integer of 1 to 9, preferably an integer of 1 to 5, and more preferably 1 or 2.

In the formula (a0-1), when Ra ¹ and Ra ² are not bonded to each other, X is the 1-position, 2-position, 3 of the 6-oxabicyclo [3.2.1 ^1,5 ] octane ring. It may be bonded to any of the 4th, 4th, 5th or 8th positions, and is preferably bonded to the 1st position (α-position of the lactone) or the 2nd position. It is particularly preferable to bond to the position of the lactone α-position).
Further, when Ra ¹ and Ra ² are bonded to each other, X represents 1-position, 4-position, 5-position, 6-position such as 3-oxatricyclo [4.2.1.0 ^4,8 ] nonane ring. May be bonded to any position such as position, 7 position, 8 position or 9 position, and in particular, the 1 position or 9 position of 3-oxatricyclo [4.2.1.0 ^4,8 ] nonane ring ( Or a position corresponding to these) is preferable, and among these, it is particularly preferable that the bond is bonded to the 1-position (or the position corresponding to this; the α-position of the lactone).

Specific examples of the structural unit (a0) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group. X is the same as X in the formula (a0-1).

As the structural unit (a0) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
The proportion of the structural unit (a0) in the component (A1) is preferably 5 to 70 mol%, and preferably 10 to 60 mol%, based on the total of all structural units constituting the component (A1). More preferably, 10-50 mol% is further more preferable, and 10-40 mol% is especially preferable.
By setting the proportion of the structural unit (a0) to a preferable upper limit value or less, a resist pattern having a good shape can be easily obtained while maintaining high sensitivity. On the other hand, by setting it to be equal to or more than the preferable lower limit value, sensitivity is improved and lithography characteristics such as resolution and exposure margin (EL margin) are also improved.

(Other structural units)
In addition to the structural unit (a0), the component (A1) may further have another structural unit.
The other structural unit is not particularly limited as long as it is a structural unit that is not classified into the structural unit (a0) described above. For ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser), etc. Many conventionally known ones that can be used for resist resins can be used, and examples include the structural units (a1) to (a4) shown below and structural units that generate an acid upon exposure. .

Structural unit (a1):
In the resist composition of this embodiment, the component (A1) preferably has a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid, in addition to the structural unit (a0). .
When the resist composition of this embodiment contains a polymer compound having the structural unit (a0) and the structural unit (a1), the resist film formed using the resist composition is exposed to light in the resist film. In the structural unit (a1), at least a part of the bonds in the structure is cleaved by the action of an acid, and the polarity increases. As described above, since the polarity of the component (A1) changes before and after exposure, by using the component (A1), a good development contrast can be obtained not only in the alkali development process but also in the solvent development process. And the resist composition of this aspect becomes a positive type in an alkali development process, and becomes a negative type in a solvent development process.

The “acid-decomposable group” is an acid-decomposable group that can cleave at least part of bonds in the structure of the acid-decomposable group by the action of an acid.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is more preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
Here, the “acid-dissociable group” means (i) a group having acid-dissociable properties capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid, Alternatively, (ii) after a partial bond is cleaved by the action of an acid, a further decarboxylation reaction occurs, whereby a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group is cleaved. Both of the resulting groups.
The acid-dissociable group constituting the acid-decomposable group must be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a polarity higher than that of the acid dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the solubility in the developer changes relatively. When the developer is an alkaline developer, the solubility increases. When the developer is an organic developer, the solubility increases. Decrease.

Examples of the acid dissociable group include those that have been proposed so far as the acid dissociable group of the base resin for a chemically amplified resist.
Specifically, what is proposed as an acid dissociable group of a base resin for a chemically amplified resist includes an “acetal acid dissociable group” and a “tertiary alkyl ester acid dissociable group” described below. , “Tertiary alkyloxycarbonyl acid dissociable group”.

・ Acetal type acid dissociable group:
Examples of the acid dissociable group that protects a carboxy group or a hydroxyl group among the polar groups include, for example, an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as “acetal acid dissociable group”). May be included).

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

[Wherein, Ra ′ ¹ and Ra ′ ² are a hydrogen atom or an alkyl group, Ra ′ ³ is a hydrocarbon group, and Ra ′ ³ is bonded to either Ra ′ ¹ or Ra ′ ² to form a ring. May be formed. ]

In formula (a1-r-1), at least one of Ra ′ ¹ and Ra ′ ² is preferably a hydrogen atom, and more preferably both are hydrogen atoms.
In the case where Ra ′ ¹ or Ra ′ ² is an alkyl group, the alkyl group is the alkyl group mentioned as the substituent that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester. The same thing is mentioned, A C1-C5 alkyl group is preferable. Specifically, a linear or branched alkyl group is preferable. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like can be given. More preferred is a methyl group.

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

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

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

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

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

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

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

[Wherein, Ra ′ ^{4 to} Ra ′ ⁶ are each a hydrocarbon group, and Ra ′ ⁵ and Ra ′ ⁶ may be bonded to each other to form a ring. ]

As the hydrocarbon group for Ra ′ ^{4 to} Ra ′ ^6, the same groups as those described above for Ra ′ ³ can be mentioned.
Ra ′ ⁴ is preferably an alkyl group having 1 to 5 carbon atoms. When Ra ′ ⁵ and Ra ′ ⁶ are bonded to each other to form a ring, a group represented by general formula (a1-r2-1) shown below can be given. On the other hand, when Ra ′ ^{4 to} Ra ′ ⁶ are not bonded to each other and are independent hydrocarbon groups, groups represented by the following general formula (a1-r2-2) are exemplified.

［式中、Ｒａ’^１０は炭素数１〜１０のアルキル基、Ｒａ’^１１はＲａ’^１０が結合した炭素原子と共に脂肪族環式基を形成する基、Ｒａ’^１２〜Ｒａ’^１４は、それぞれ独立に炭化水素基を示す。］

[Wherein, Ra ′ ¹⁰ is an alkyl group having 1 to ¹⁰ carbon atoms, Ra ′ ¹¹ is a group that forms an aliphatic cyclic group together with a carbon atom to which Ra ′ ¹⁰ is bonded, and Ra ′ ^{12 to} Ra ′ ¹⁴ are Independently represents a hydrocarbon group. ]

Formula (a1-r2-1) in, Ra 'alkyl group having 1 to 10 carbon atoms ^10, Ra in formula (a1-r-1)' was mentioned as the linear or branched alkyl group of ³ Groups are preferred. In formula (a1-r2-1), the aliphatic cyclic group formed by Ra ′ ¹¹ together with the carbon atom to which Ra ′ ¹⁰ is bonded is a monocyclic group of Ra ′ ³ in formula (a1-r-1) or The groups mentioned as the aliphatic hydrocarbon group which is a polycyclic group are preferred.

In formula (a1-r2-2), Ra ′ ¹² and Ra ′ ¹⁴ are preferably each independently an alkyl group having 1 to 10 carbon atoms, and the alkyl group is represented by Ra in formula (a1-r-1). 'The group mentioned as a linear or branched alkyl group of ³ is more preferable, It is more preferable that it is a C1-C5 linear alkyl group, It is especially preferable that it is a methyl group or an ethyl group .
In formula (a1-r2-2), Ra ′ ¹³ represents a linear or branched alkyl group or monocyclic group exemplified as the hydrocarbon group for Ra ′ ³ in formula (a1-r-1). Or it is preferable that it is an aliphatic hydrocarbon group which is a polycyclic group. Among these, the group mentioned as the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of Ra ′ ³ is more preferable.

  Specific examples of the group represented by the formula (a1-r2-1) are given below. * Represents a bond (hereinafter the same in this specification).

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

Tertiary alkyloxycarbonyl acid dissociable group:
Examples of the acid dissociable group for protecting the hydroxyl group among the polar groups include an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as “tertiary alkyloxycarbonyl acid dissociable group” ”).

［式中、Ｒａ’^７〜Ｒａ’^９はそれぞれアルキル基である。］

[Wherein, Ra ′ ^{7 to} Ra ′ ⁹ each represents an alkyl group. ]

In formula (a1-r-3), Ra ′ ^{7 to} Ra ′ ⁹ are each preferably an alkyl group having 1 to 5 carbon atoms, and more preferably 1 to 3 groups.
The total carbon number of each alkyl group is preferably 3-7, more preferably 3-5, and most preferably 3-4.

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

Among the above, the structural unit (a1) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent.
Preferable specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2).

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

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Va ¹ is a divalent hydrocarbon group which may have an ether bond, n _a1 is 0 to 2, and Ra ¹ is the above formula (a1-r-1) or (a1-r-2) It is an acid dissociable group represented by. Wa ¹ is a n _a2 +1 valent hydrocarbon group, n _a2 is 1 to 3, and Ra ² is an acid dissociation property represented by the above formula (a1-r-1) or (a1-r-3). It is a group. ]

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

In the formula (a1-1), the divalent hydrocarbon group optionally having an ether bond of Va ^{1 has} an ether bond as Va ⁰ in the formula (a0-1) as a substituent. This is the same as the case where the divalent hydrocarbon group may be used.

In the formula (a1-2), the n _a2 +1 valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group including a ring in the structure, or a linear or branched aliphatic hydrocarbon group. Examples thereof include a combination of an aliphatic hydrocarbon group containing a ring in the structure.
The n _a2 +1 valence is preferably 2 to 4, and more preferably 2 or 3.

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

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

As the structural unit (a1) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
When the component (A1) has the structural unit (a1), the proportion of the structural unit (a1) in the component (A1) is 1 to 50 mol% with respect to the total of all the structural units constituting the component (A1). Preferably, 5-45 mol% is more preferable, and 5-40 mol% is further more preferable.
By setting the ratio of the structural unit (a1) to a preferable lower limit value or more, a resist pattern can be easily obtained, and lithography properties such as sensitivity, resolution, roughness improvement, or EL margin are improved. On the other hand, the balance with another structural unit can be taken by setting it as a preferable upper limit or less. In the component (A1), the higher the proportion of the structural unit (a1), the greater the effect of reducing the roughness of the resist pattern.

Structural unit (a2):
In the resist composition of this embodiment, in addition to the structural unit (a0) and the structural unit (a1), the component (A1) further includes a lactone-containing cyclic group, an —SO ₂ — containing cyclic group, or a carbonate-containing ring. It is preferable to have a structural unit (a2) containing a formula group (excluding the structural unit (a0)).
The lactone-containing cyclic group, —SO ₂ — containing cyclic group or carbonate-containing cyclic group of the structural unit (a2) can be used to adhere the resist film to the substrate when the component (A1) is used for forming the resist film. It is effective in enhancing the sex. In addition, by including the structural unit (a2), in the alkali development process, the solubility of the resist film in the alkaline developer is increased during development.

The “lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —O—C (═O) — in the ring skeleton. The lactone ring is counted as the first ring. When only the lactone ring is present, 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-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone-containing cyclic group in the structural unit (a2) is not particularly limited, and any lactone-containing cyclic group can be used. Specific examples include groups represented by general formulas (a2-r-1) to (a2-r-7) shown below.

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

[Wherein, Ra ′ ²¹ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group; A ″ is an oxygen atom (—O—) or a sulfur atom (— S—) may be an alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom, n ′ is an integer of 0 to 2, and m ′ is 0 or 1. ]

In the general formula (a2-r-1) ~ (a2-r-7), the alkyl group in Ra ^'21, preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group in the ra ^'21, preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, groups of the the Ra 'group and an oxygen atom mentioned as the alkyl group in ²¹ (-O-) are linked and the like.
Examples of the halogen atom in Ra ′ ²¹ 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 for ^21, the Ra' Ra part or all of the hydrogen atoms of the alkyl group in ²¹ can be mentioned it has been substituted with the aforementioned halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In —COOR ″ and —OC (═O) R ″ in Ra ′ ²¹ , R ″ is any hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group. It is.
The alkyl group for R ″ may be linear, branched or cyclic, and preferably has 1 to 15 carbon atoms.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorinated alkyl group; a polycycloalkane such as a bicycloalkane, tricycloalkane or tetracycloalkane A group in which one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane, cyclohexane, etc .; more specifically, a group in which one or more hydrogen atoms are removed; adamantane, norbornane, isobornane, Examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as cyclodecane or tetracyclododecane. That.
Examples of the lactone-containing cyclic group for R ″ include the same groups as those represented by general formulas (a2-r-1) to (a2-r-7).
The carbonate-containing cyclic group for R ″ is the same as the carbonate-containing cyclic group described later, and specifically, groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. Is mentioned.
The —SO ₂ — containing cyclic group in R ″ is the same as the later-described —SO ₂ — containing cyclic group, and specifically, is represented by the general formulas (a5-r-1) to (a5-r-4) And groups represented respectively by
As the hydroxyalkyl group in Ra ′ ²¹ , those having 1 to 6 carbon atoms are preferable, and specific examples include a group in which at least one hydrogen atom of the alkyl group in Ra ′ ²¹ is substituted with a hydroxyl group. .

In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A ″ is linear or branched. An alkylene group is preferred, and examples include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a terminal of the alkylene group or a carbon atom. between atoms -O- or -S- can be mentioned a group intervening, for example, _{-O-CH 2 -, - CH} 2 -O-CH 2 -, - S-CH 2 -, - CH 2 -S-CH _As A ″, an alkylene group having 1 to 5 carbon atoms or —O— is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable.

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

The “—SO ₂ -containing cyclic group” refers to a cyclic group containing a ring containing —SO ₂ — in the ring skeleton, specifically, the sulfur atom (S) in —SO ₂ — is It is a cyclic group that forms part of the ring skeleton of the cyclic group. The ring containing —SO ₂ — in the ring skeleton is counted as the first ring, and when it is only the ring, it is a monocyclic group, and when it has another ring structure, it is a polycyclic group regardless of the structure. Called. The —SO ₂ — containing cyclic group may be a monocyclic group or a polycyclic group.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton A cyclic group containing a sultone ring to be formed is preferable.
More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by general formulas (a5-r-1) to (a5-r-4) shown below.

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

[Wherein, Ra ′ ⁵¹ independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group; A ″ is a carbon that may contain an oxygen atom or a sulfur atom It is a C 1-5 alkylene group, an oxygen atom or a sulfur atom, and n ′ is an integer of 0-2. ]

In general formulas (a5-r-1) to (a5-r-4), A ″ represents the general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Same as A ″ in the middle.
As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ⁵¹ , the above general formulas (a2-r-1) to ( a2-r-7) as in the same as those exemplified in the description of the Ra ^'21 of the like.
Specific examples of groups represented by general formulas (a5-r-1) to (a5-r-4) are given below. “Ac” in the formula represents an acetyl group.

The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C (═O) —O— in the ring skeleton. When the carbonate ring is counted as the first ring, the carbonate ring alone is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
Any carbonate ring-containing cyclic group can be used without any particular limitation. Specific examples include groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

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

[ ^Wherein , Ra ′ ^x31 each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group; A ″ is a carbon that may contain an oxygen atom or a sulfur atom It is an alkylene group of formulas 1 to 5, an oxygen atom or a sulfur atom, p ′ is an integer of 0 to 3, and q ′ is 0 or 1. ]

In the general formulas (ax3-r-1) to (ax3-r-3), A ″ represents the general formulas (a2-r-2), (a2-r-3), (a2-r-5). Same as A ″ in the middle.
As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ³¹ , the above general formulas (a2-r-1) to ( a2-r-7) as in the same as those exemplified in the description of the Ra ^'21 of the like.
Specific examples of groups represented by general formulas (ax3-r-1) to (ax3-r-3) are given below.

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

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

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Ya ²¹ is a single bond or a divalent linking group. La ²¹ represents —O—, —COO—, —CON (R ′) —, —OCO—, —CONHCO— or —CONHCS—, and R ′ represents a hydrogen atom or a methyl group. However, when La ²¹ is —O—, Ya ²¹ is not —CO—. Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or an —SO ₂ -containing cyclic group. ]

In formula (a2-1), R is the same as described above.
The divalent linking group of Ya ²¹ is not particularly limited, and preferred examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom.

-Divalent hydrocarbon group which may have a substituent:
When Ya ²¹ is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

.. Aliphatic hydrocarbon group in Ya ²¹ The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

... Linear or branched aliphatic hydrocarbon group The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. 1-4 are more preferable, and 1-3 are most preferable.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
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 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene 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 alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

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

... An aliphatic hydrocarbon group containing a ring in the structure As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (A group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, the cyclic fat And a group in which an aromatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
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. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent 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. Most preferred is an ethoxy group.
Examples of the halogen atom as the substituent 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 include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.

.. Aromatic hydrocarbon group in Ya ²¹ The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, 5-20 are more preferable, 6-15 are more preferable, and 6-12 are especially preferable. However, the carbon number does not include the carbon number in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms, and the like. Can be mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings A group obtained by removing two hydrogen atoms from (for example, biphenyl, fluorene, etc.); 1 of the hydrogen atoms of a group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring A group substituted with an alkylene group (for example, an aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) A group in which one atom is further removed). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

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

-A divalent linking group containing a hetero atom:
When Ya ²¹ is a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C (═O) —O—, —C (═O) —, and —O—C. (═O) —O—, —C (═O) —NH—, —NH—, —NH—C (═NH) — (H may be substituted with a substituent such as an alkyl group or an acyl group). _{.), - S -, -} S (= O) 2 -, - S (= O) 2 -O-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 - C (═O) —O—, —C (═O) —O—Y ²¹ —, — [Y ²¹ —C (═O) —O] _{m ″} —Y ²² —, —Y ²¹ —O—C ( Group represented by ═O) —Y ²² — or —Y ²¹ —S (═O) ₂ —O—Y ²² —, wherein Y ²¹ and Y ²² each independently have a substituent. A divalent hydrocarbon group, It is an oxygen atom, m "is an integer of 0 to 3. ] Etc. are mentioned.
The divalent linking group containing a hetero atom is -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH). In the case of-, the H may be substituted with a substituent such as an alkyl group or acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 -C (= O) -O -, - C (= O) -O-Y 21 -, - [Y 21 - C (═O) —O] _{m ″} —Y ²² —, —Y ²¹ —O—C (═O) —Y ²² — or —Y ²¹ —S (═O) ₂ —O—Y ²² —, wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, and the divalent hydrocarbon group is exemplified in the description of the divalent linking group. And (the divalent hydrocarbon group which may have a substituent).
Y ²¹ is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. preferable.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, and more preferably a methylene group, an ethylene 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.
In the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ″} —Y ²² —, m ″ is an integer of 0 to 3, preferably an integer of 0 to 2, Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ″} —Y ²² — is represented by the formula —Y ²¹ —C (═O) —O—Y ²² —. Especially preferred are groups represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} —, wherein a ′ is 1 to It is an integer of 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 10, and 1 to 8 An integer of 1 is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is more preferable, and 1 is most preferable.

Ya ²¹ is preferably a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. .

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group, an —SO ₂ -containing cyclic group, or a carbonate-containing cyclic group.
The lactone-containing cyclic group, -SO ₂ -containing cyclic group, and carbonate-containing cyclic group in Ra ²¹ are each represented by the general formulas (a2-r-1) to (a2-r-7) described above. Groups represented by general formulas (a5-r-1) to (a5-r-4), groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. Are preferable.
Among these, a lactone-containing cyclic group or an —SO ₂ -containing cyclic group is preferable, and each is represented by the general formula (a2-r-1), (a2-r-2), or (a5-r-1). Groups are more preferred. Specifically, the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r- Any group represented by sl-1-1) and (r-sl-1-18) is more preferred.

As the structural unit (a2) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
When the component (A1) has the structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 80 mol% with respect to the total of all the structural units constituting the component (A1). It is more preferably 10 to 70 mol%, further preferably 10 to 65 mol%, particularly preferably 10 to 60 mol%.
By setting the proportion of the structural unit (a2) to a preferable lower limit value or more, the effect of including the structural unit (a2) can be sufficiently obtained. On the other hand, by setting it to a preferable upper limit value or less, Therefore, various lithography characteristics (exposure margin (EL margin), etc.) and pattern shape are improved.

Structural unit (a3):
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (excluding those corresponding to any of the structural units (a0), (a1), or (a2) described above).
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) increases, which contributes to the improvement of resolution.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group. For example, a resin for a resist composition for an ArF excimer laser can be appropriately selected from those proposed. The cyclic group is preferably a polycyclic group, and more preferably 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 not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any structural unit can be used.
The structural unit (a3) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and includes a polar group-containing aliphatic hydrocarbon group A structural unit is preferred.
The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), the formula ( The structural unit represented by a3-3) is preferred.

［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 3-position of the adamantyl group is particularly preferred.

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

  In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

The structural unit (a3) contained in the component (A1) may be one type or two or more types.
When the component (A1) has the structural unit (a3), it is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all structural units constituting the component (A1). 5-35 mol% is more preferable.
By setting the proportion of the structural unit (a3) to be equal to or more than the preferable lower limit, the effect of including the structural unit (a3) can be sufficiently obtained, and the lithography characteristics such as EL margin can be further improved. On the other hand, by setting it to a preferable upper limit value or less, it becomes easy to balance with other structural units.

Structural unit (a4):
The structural unit (a4) is a structural unit containing an acid non-dissociable aliphatic cyclic group.
When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Moreover, the hydrophobicity of (A) component increases. The improvement in hydrophobicity is thought to contribute to the improvement in resolution, resist pattern shape, etc., particularly in the case of a solvent development process.
The “acid non-dissociable cyclic group” in the structural unit (a4) means that the acid is generated when an acid is generated in the resist composition by exposure (for example, when an acid is generated from the component (B) described later). Is a cyclic group that remains in the structural unit as it is without dissociating even when.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic cyclic group is preferable. As the cyclic group, many conventionally known groups can be used as resin components of resist compositions such as for ArF excimer laser and for KrF excimer laser (preferably for ArF excimer laser). .
In particular, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl 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 structural units represented by general formulas (a4-1) to (a4-7) shown below.

［式中、Ｒ^αは前記と同じである。］

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

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

  In the resist composition of this embodiment, the component (A) includes the polymer compound (A1) having the structural unit (a0). Specifically, as the component (A1), the structural unit (a0) and Examples thereof include a polymer compound having a repeating structure of the structural unit (a1) and the structural unit (a2).

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, 2000 to 2000 20000 is most preferred.
When the Mw of the component (A1) is less than or equal to the preferable upper limit value in this range, there is sufficient solubility in a resist solvent to be used as a resist. The resist pattern has a good cross-sectional shape.
The dispersity (Mw / Mn) of the component (A1) is not particularly limited, but is preferably 1.0 to 5.0, more preferably 1.0 to 4.0, and most preferably 1.0 to 3.0. . In addition, Mn shows a number average molecular weight.

As the component (A1), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, still more preferably 75% by mass or more, and 100% by mass with respect to the total mass of the component (A). It may be. When the ratio is 25% by mass or more, a resist pattern excellent in various lithography characteristics such as high sensitivity and roughness improvement is easily formed.

In the resist composition of this embodiment, as the component (A), a base material component (hereinafter referred to as “component (A2)”) that does not correspond to the component (A1) and whose solubility in the developer is changed by the action of an acid. You may use together.
The component (A2) is not particularly limited, and is conventionally known as a substrate component for a chemically amplified resist composition (for example, for ArF excimer laser, for KrF excimer laser (preferably ArF excimer laser). Base resin) and the like may be arbitrarily selected and used. (A2) A component may be used individually by 1 type and may be used in combination of 2 or more type.

In the resist composition of this embodiment, the component (A) may be used alone or in combination of two or more.
In the resist composition of this embodiment, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<(B) component>
In the resist composition of this embodiment, the component (B) is an acid generator component that generates an acid upon exposure.
The acid dissociation constant (pKa) of the acid generated by exposure of the component (B) is preferably 0 or less, more preferably -1 or less, still more preferably -15 to -1, and particularly preferably- 12 to -1.
When the pKa of the acid generated by the exposure of the component (B) is preferably 0 or less, an acid having a relatively strong acid strength is generated by the exposure, and the pattern is sufficiently formed by the action of the acid and the component (A). Easy to be done.

The term “acid dissociation constant (pKa)” as used herein means that a compound having a lower molecular orbital energy in the structure of the acid in the anion state has a higher acid strength (a smaller pKa value). This means a value calculated by performing the calculation method.
Method of calculation:
(1) The structure of the anion state of the acid is optimized by the CAChe PM3 method.
(2) The HOMO (highest occupied molecular orbital) energy (eV) is obtained from the molecular orbital calculation.
(3) An equation of a linear relationship established between a substance having a known pKa (actual value) in an aqueous solution and the HOMO energy obtained in (1) and (2) of the substance is derived.
(4) Calculate the pKa (calculated value) for the target acid by calculating the HOMO energy from (1) and (2) and substituting the HOMO energy into the linear relationship equation derived in (3). To do.
According to the above (1) to (4), the pKa (calculated value) can also be calculated by obtaining the HOMO energy for a new acid.
The reason for obtaining the HOMO energy of only the anion state of the acid is that the acid strength mainly depends on the structure of the anion state of the acid (it does not depend on the cation structure).

The equation of the linear relationship in the calculation method (3) can be derived by following the following procedures (i) to (iii).
(I) The acid dissociation constant (pKa) at 25 ° C. of the following 8 compounds is actually measured.
The acid dissociation constant (pKa) can be measured in a dimethyl sulfoxide (DMSO) with a pKa value measuring device pKa Analyzer PRO (Advanced Analytical Technologies, Inc).
Compound (actual value of pKa):
Chloroacetic acid (pKa 2.68), acetic acid (pKa 4.56), trichloroacetic acid (pKa 0.66), phenol (pKa 9.82), dichloroacetic acid (pKa 1.3), fluoroacetic acid (pKa 2.59), hexanoic acid (pKa 4 .63), O-fluorophenol (pKa 8.49).
(Ii) HOMO energy is calculated | required about the said compound from calculation method (1) and calculation method (2), respectively.
Chloroacetic acid (−4.395), acetic acid (−3.925), trichloroacetic acid (−5.073), phenol (−2.691), dichloroacetic acid (−4.763), fluoroacetic acid (−4.31) ), Hexanoic acid (-4.076), O-fluorophenol (-2.929).
(Iii) About the said compound, a horizontal axis | shaft is plotted as the pKa value measured by (i), and a vertical axis | shaft is plotted as the HOMO energy (eV) calculated | required by (ii), A linear regression line is drawn and the formula of this linear relationship is derived. (R ² = 0.9868).
(HOMO energy) = 0.2511 × (pKa value) −5.1103

As (B) component, what has been proposed as an acid generator 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, and diazomethanes such as poly (bissulfonyl) diazomethanes. Examples include an acid generator, a nitrobenzyl sulfonate acid generator, an imino sulfonate acid generator, and a disulfone acid generator. Of these, it is preferable to use an onium salt acid generator.

  Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as “(b-1) component”) and a general formula (b-2). A compound (hereinafter also referred to as “(b-2) component”) or a compound represented by the general formula (b-3) (hereinafter also referred to as “(b-3) component”) can be used.

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

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

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

Cyclic group which may have a substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

The aromatic hydrocarbon group for R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring of the aromatic hydrocarbon group in R ¹⁰¹ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a part of carbon atoms constituting these aromatic rings substituted with a heteroatom. An aromatic heterocyclic ring is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group in R ¹⁰¹ is a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and one of the hydrogen atoms of the aromatic ring is alkylene. And a group substituted with a group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

Examples of the cyclic aliphatic hydrocarbon group for R ¹⁰¹ include an aliphatic hydrocarbon group containing a ring in the structure.
As the aliphatic hydrocarbon group containing a ring in this structure, an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), an alicyclic hydrocarbon group is linear or branched Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms. Examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
Among them, the cyclic aliphatic hydrocarbon group for R ¹⁰¹ is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or polycycloalkane, and more preferably a group obtained by removing one hydrogen atom from a polycycloalkane. An adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

The linear or branched aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and 1 to 4 carbon atoms. Is more preferable, and 1-3 are most preferable.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
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 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene 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 alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

Examples of the substituent in the cyclic hydrocarbon group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group (—C (═O) —), an ether bond (—O—). ), An ester bond (—C (═O) —O—), a nitro group, and the like.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent, a part or all of hydrogen atoms such as an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, and the like And a group substituted with a halogen atom.
A carbonyl group (—C (═O) —), an ether bond (—O—), and an ester bond (—C (═O) —O—) as a substituent group are methylene groups ( It is a group that substitutes —CH ₂ —).

In addition, the cyclic hydrocarbon group for R ¹⁰¹ may contain a hetero atom such as a heterocyclic ring. Specifically, the lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), and the general formulas (a5-r-1) to (a5-r- -SO 2 respectively represented by 4) _- containing cyclic group, heterocyclic group listed other less like.

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

A chain-like alkenyl group which may have a substituent:
The chain alkenyl group for R ¹⁰¹ may be either linear or branched, preferably has 2 to 10 carbon atoms, more preferably 2 to 5, still more preferably 2 to 4, more preferably 3 Is particularly preferred. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group and the like.
Among the above, the chain alkenyl group is more preferably a vinyl group or a propenyl group, and particularly preferably a vinyl group.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group (—C (═O) —), an ether bond (—O—). ), An ester bond (—C (═O) —O—), a nitro group, an amino group, the cyclic group in R ^{101, and} the like.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent, a part or all of hydrogen atoms such as an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, and the like And a group substituted with a halogen atom.
A carbonyl group (—C (═O) —), an ether bond (—O—), or an ester bond (—C (═O) —O—) as a substituent constitutes a chain alkyl group or alkenyl group. It is a group that substitutes a methylene group (—CH ₂ —).

Among the above, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, phenyl groups, naphthyl groups, groups obtained by removing one or more hydrogen atoms from polycycloalkane, and lactones represented by the above formulas (a2-r-1) to (a2-r-7), respectively. The containing cyclic group, the —SO ₂ -containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively, and the like are preferable.

In formula (b-1), Y ¹⁰¹ represents a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: —O—), an ester bond (—C (═O) —O—), and an oxycarbonyl group (—O—C (═O). )-), Amide bond (—C (═O) —NH—), carbonyl group (—C (═O) —), carbonate bond (—O—C (═O) —O—), etc. A combination of a non-hydrocarbon oxygen atom-containing linking group and an alkylene group; and the like. A sulfonyl group (—SO ₂ —) may be further linked to the combination. Examples of the combination include linking groups represented by the following formulas (y-al-1) to (y-al-7), respectively.

［式中、Ｖ’^１０１は単結合または炭素数１〜５のアルキレン基であり、Ｖ’^１０２は炭素数１〜３０の２価の飽和炭化水素基である。］

[Wherein, V ′ ¹⁰¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V ′ ¹⁰² is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms. ]

The divalent saturated hydrocarbon group for V ′ ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms.

The alkylene group for V ′ ¹⁰¹ and V ′ ¹⁰² may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred.
Specific examples of the alkylene group in V ′ ¹⁰¹ and V ′ ¹⁰² 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 Groups [—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 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 (CH 3) CH ₂ - and the like alkyl trimethylene group; tetramethylene _{[-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; pentamethylene group _{[-CH 2 CH 2 CH 2 CH} 2 CH 2 -] , and the like.
Moreover, some methylene groups in the alkylene group in V ′ ¹⁰¹ or V ′ ¹⁰² may be substituted with a C 5-10 divalent aliphatic cyclic group. The aliphatic cyclic group is obtained by further removing one hydrogen atom from an aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group in Ra ′ ³ in the formula (a1-r-1). Is preferably a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group.

Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or an ether bond, and linking groups represented by the above formulas (y-al-1) to (y-al-5) are preferred.

In formula (b-1), V ¹⁰¹ represents a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group for V ¹⁰¹ preferably have 1 to 4 carbon atoms. ^Examples of the fluorinated alkylene group for V ¹⁰¹ include groups in which some or all of the hydrogen atoms of the alkylene group for V ¹⁰¹ have been substituted with fluorine atoms. Among ^{them, V 101} is preferably a single bond, or a fluorinated alkylene group having 1 to 4 carbon atoms.

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

The acid dissociation constant (pKa) of the acid generated by exposure of the component (b-1) is about -12 to -1, preferably about -7 to -1.
(B-1) Specific examples of the anion moiety of the component, for example, if the Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion or perfluorobutane sulfonate anion can be exemplified; Y ¹⁰¹ is In the case of a divalent linking group containing an oxygen atom, anions represented by any one of the following formulas (an-1) to (an-3) can be mentioned.

［式中、Ｒ”^１０１は、置換基を有していてもよい脂肪族環式基、前記式（ｒ−ｈｒ−１）〜（ｒ−ｈｒ−６）でそれぞれ表される基、又は置換基を有していてもよい鎖状のアルキル基であり；Ｒ”^１０２は、置換基を有していてもよい脂肪族環式基、前記式（ａ２−ｒ−１）〜（ａ２−ｒ−７）でそれぞれ表されるラクトン含有環式基、又は前記一般式（ａ５−ｒ−１）〜（ａ５−ｒ−４）でそれぞれ表される−ＳＯ_２−含有環式基であり；Ｒ”^１０３は、置換基を有していてもよい芳香族環式基、置換基を有していてもよい脂肪族環式基、又は置換基を有していてもよい鎖状のアルケニル基であり；ｖ”はそれぞれ独立に０〜３の整数であり、ｑ”はそれぞれ独立に１〜２０の整数であり、ｔ”は１〜３の整数であり、ｎ”は０または１である。］

[Wherein R ″ ¹⁰¹ represents an aliphatic cyclic group which may have a substituent, a group represented by each of the above formulas (r-hr-1) to (r-hr-6), or a substituent. A chain-like alkyl group which may have a group; R ″ ¹⁰² represents an aliphatic cyclic group which may have a substituent, the above formulas (a2-r-1) to (a2-r); lactone-containing cyclic group represented respectively by -7), or the formula (a5-r-1) ~ (a5-r-4) with -SO ₂ respectively represented - be-containing cyclic group; R ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. Yes; v ″ is independently an integer of 0 to 3, q ″ is independently an integer of 1 to 20, t ″ is an integer of 1 to 3, and n ″ is 0 or 1 a is.]

The aliphatic cyclic group which may have a substituent of R ″ ¹⁰¹ , R ″ ¹⁰² and R ″ ¹⁰³ is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in R ¹⁰¹ . Examples of the substituent include the same substituents that may be substituted for the cyclic aliphatic hydrocarbon group in R ¹⁰¹ .

The aromatic cyclic group which may have a substituent in R ″ ¹⁰³ is preferably the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R ¹⁰¹ . And the same substituents that may be substituted for the aromatic hydrocarbon group in R ¹⁰¹ .

The chain alkyl group which may have a substituent in R ″ ¹⁰¹ is preferably the group exemplified as the chain alkyl group in R ^101. The chain in R ″ ¹⁰³ has a substituent. The good chain alkenyl group is preferably the group exemplified as the chain alkenyl group in R ¹⁰¹ .

-Anion part of component (b-2) In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ may each independently have a cyclic group which may have a substituent or a substituent. Examples thereof include a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same as those described above for R ¹⁰¹ in formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably a chain alkyl group which may have a substituent, and are a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. It is more preferable.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. The carbon number of the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible for reasons such as good solubility in a resist solvent within the above carbon number range. In addition, in the chain alkyl group of R ¹⁰⁴ and R ^105, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and against high-energy light and electron beams of 200 nm or less Since transparency improves, it is preferable. The proportion of fluorine atoms in the chain alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. Perfluoroalkyl group.
In formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each of them is the same as V ¹⁰¹ in formula (b-1). Can be mentioned.
In formula (b-2), L ^{101 to} L ¹⁰² each independently represents a single bond or an oxygen atom.
The acid dissociation constant (pKa) of the acid generated by exposure of the component (b-2) is about −12 to −1, preferably about −12 to −4.

-Anion part of (b-3) component In formula (b-3), R < ¹⁰⁶ > -R < ¹⁰⁸ > may have the cyclic group which may have a substituent, and a substituent each independently. Examples thereof include a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same as those described above for R ¹⁰¹ in formula (b-1).
L ^{103 to} L ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —.
The acid dissociation constant (pKa) of the acid generated by exposure of the component (b-3) is about -15 to -1, preferably about -14 to -4.

{Cation part}
In formulas (b-1), (b-2), and (b-3), M ′ ^{m +} is an m-valent onium cation, and a sulfonium cation and an iodonium cation are preferable. Specific examples of (M ′ ^{m +} ) _{1 / m} include organic cations represented by the following general formulas (ca-1) to (ca-4), respectively.

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

[Wherein, R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and R ^{201 to} R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ and R ^{211 to} R ²¹² may be bonded to each other to form a ring together with the sulfur atom in the formula. R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ²¹⁰ is an aryl group, alkyl group, alkenyl group, or —SO ₂ — containing an optionally substituted substituent. A cyclic group, L ²⁰¹ represents —C (═O) — or —C (═O) —O—, Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group, and x represents 1 or 2 and W ²⁰¹ represents a (x + 1) -valent linking group. ]

Examples of the aryl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² is a chain or cyclic alkyl group and preferably has 1 to 30 carbon atoms.
The alkenyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² preferably has 2 to 10 carbon atoms.
Examples of the substituent that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, And groups represented by formulas (ca-r-1) to (ca-r-7), respectively.

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

[Wherein, R ′ ²⁰¹ each independently represents a hydrogen atom, an optionally substituted cyclic group, a chain alkyl group, or a chain alkenyl group. ]

The cyclic group which may have a substituent of R ′ ^201, the chain alkyl group which may have a substituent, or the chain alkenyl group which may have a substituent are as described above. In addition to the same as R ^{101 in} the formula (b-1), the cyclic group which may have a substituent or the chain alkyl group which may have a substituent may include: The same thing as the acid dissociable group represented by the above-mentioned formula (a1-r-2) is also mentioned.

^{R 201 ~R 203, R 206 ~R} 207, R 211 ~R 212 , when bonded to each other to form a ring with the sulfur atom, a sulfur atom, an oxygen atom, or a hetero atom such as nitrogen atom, carbonyl _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (. the _{R N} is an alkyl group having 1 to 5 carbon atoms), etc. You may couple | bond through the functional group of. As the ring to be formed, one ring containing a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring, including the sulfur atom. preferable. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferable. A ring may be formed.

R ²¹⁰ may have an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. -SO ₂ - containing cyclic group.
The aryl group in R ^210, include unsubstituted aryl group having 6 to 20 carbon atoms, a phenyl group, a naphthyl group.
The alkyl group for R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms.
The —SO ₂ — containing cyclic group which may have a substituent in R ²¹⁰ is the same as the “—SO ₂ — containing cyclic group” of Ra ^{21 in} the aforementioned general formula (a2-1). The group represented by the general formula (a5-r-1) described above is preferable.

Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group.
Examples of the arylene group for Y ²⁰¹ include a group in which one hydrogen atom has been removed from the aryl group exemplified as the aromatic hydrocarbon group for R ¹⁰¹ in the aforementioned formula (b-1).
As the alkylene group and alkenylene group for Y ²⁰¹ , the same aliphatic hydrocarbon groups as divalent hydrocarbon groups for Va ¹ in the aforementioned general formula (a1-1) can be mentioned.

In the formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x + 1) valent, that is, a divalent or trivalent linking group.
The divalent linking group in W ²⁰¹ is preferably a divalent hydrocarbon group which may have a substituent, and examples thereof include the same hydrocarbon groups as those of Ya ²¹ in the general formula (a2-1). . The divalent linking group in W ²⁰¹ may be linear, branched or cyclic, and is preferably cyclic. Of these, a group in which two carbonyl groups are combined at both ends of the arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.
^Examples of the trivalent linking group in W ²⁰¹ include a group obtained by removing one hydrogen atom from the divalent linking group in W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, and the like. Can be mentioned. The trivalent linking group in W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

  Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-67), respectively.

［式中、ｇ１、ｇ２、ｇ３は繰返し数を示し、ｇ１は１〜５の整数であり、ｇ２は０〜２０の整数であり、ｇ３は０〜２０の整数である。］

[Wherein, g1, g2, and g3 represent the number of repetitions, g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20. ]

［式中、Ｒ”^２０１は水素原子又は置換基であって、置換基としては前記Ｒ^２０１〜Ｒ^２０７、およびＲ^２１０〜Ｒ^２１２が有していてもよい置換基として挙げたものと同様である。］

[Wherein R ″ ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as the substituents that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have. is there.]

  Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis (4-tert-butylphenyl) iodonium cation.

  Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

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

Among these, the cation part [(M ′ ^{m +} ) _{1 / m} ] is preferably an organic cation represented by the general formula (ca-1), and is represented by the formulas (ca-1-1) to (ca-1-67). Are more preferable.

As the component (B), one type of acid generator described above may be used alone, or two or more types may be used in combination.
Among these, as the component (B), it is particularly preferable to use an acid generator composed of a compound represented by the following general formula (b-1-1).

［式中、Ｒ^１０１’は置換基を有していてもよい環式基である。Ｒ^１０２はフッ素原子又は炭素数１〜５のフッ素化アルキル基である。Ｙ^１０１’は酸素原子を含む２価の連結基である。Ｖ^１０１は単結合、アルキレン基又はフッ素化アルキレン基である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

[Wherein, R ¹⁰¹ ′ is a cyclic group which may have a substituent. R ¹⁰² represents a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ ′ is a divalent linking group containing an oxygen atom. V ¹⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. m is an integer of 1 or more, and M ′ ^{m +} is an m-valent onium cation. ]

In the formula (b-1-1), R ¹⁰¹ ′ may be the same as the “cyclic group optionally having substituents” in R ¹⁰¹ , and a cyclic aliphatic hydrocarbon group, Heterocyclic groups are preferred. Specific examples of the heterocyclic group include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), and the general formula (a5-r-1). ) ~ (a5-r-4 ) with -SO ₂ represented respectively - containing cyclic group, heterocyclic group each represented by the chemical formula (r-hr-1) ~ (r-hr-16) Can be mentioned.
In the formula (b-1-1), Y ¹⁰¹ ′ is the same as the “divalent linking group containing an oxygen atom” in Y ¹⁰¹ in the formula (b-1).
In the formula ^{(b-1-1), R 102} , V 101, m, M 'm + ^{is, R} 102, ^V 101, m in the formula (b-1), M' is the same as ^{m +.}

In the resist composition of this embodiment, the content of the component (B) is preferably 0.5 to 60 parts by weight, more preferably 1 to 50 parts by weight, and 1 to 40 parts by weight with respect to 100 parts by weight of the component (A). Part is more preferred.
By forming the content of the component (B) within the above-mentioned preferable range, pattern formation is sufficiently performed. Moreover, when each component of a resist composition is melt | dissolved in the organic solvent, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(D1) component>
In the resist composition of this embodiment, the component (D1) is a compound represented by the following general formula (d1-1) (hereinafter referred to as “(d1-1) component”), a general formula (d1-2). Selected from the group consisting of a compound represented by the following formula (hereinafter referred to as “(d1-2) component”) and a compound represented by the general formula (d1-3) (hereinafter referred to as “(d1-3) component”). One or more compounds.
Component (D1) is a photo-disintegrating base that decomposes upon exposure and loses acid diffusion controllability, and does not act as a quencher because it decomposes and loses acid diffusion controllability (basicity) at the exposed portion of the resist film. In the unexposed area, it acts as a quencher. For this reason, when this (D1) component is contained, when forming a resist pattern, the contrast of an exposed part and an unexposed part can be improved more.

［式中、Ｒｄ^１〜Ｒｄ^４は置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、又は置換基を有していてもよい鎖状のアルケニル基である。但し、式（ｄ１−２）中のＲｄ^２における、Ｓ原子に隣接する炭素原子にはフッ素原子は結合していないものとする。Ｙｄ^１は単結合又は２価の連結基である。ｍは１以上の整数であって、Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

[Wherein Rd ^{1 to} Rd ⁴ are a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain which may have a substituent. Of the alkenyl group. However, a fluorine atom is not bonded to a carbon atom adjacent to the S atom in Rd ² in the formula (d1-2). Yd ¹ is a single bond or a divalent linking group. m is an integer of 1 or more, and M ^{m +} is each independently an m-valent organic cation. ]

-(D1-1) component (d1-1) Anion part of component:
In formula (d1-1), Rd ¹ is a cyclic group that may have a substituent, a chain alkyl group that may have a substituent, or a chain that may have a substituent. And the same as R ¹⁰¹ in the formula (b-1).
Among these, Rd ¹ may have an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. A chain alkyl group is preferred. As the substituent which these groups may have, a hydroxyl group, a fluorine atom or a fluorinated alkyl group is preferable.
As the aromatic hydrocarbon group, a phenyl group or a naphthyl group is more preferable.
The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane.
The chain alkyl group preferably has 1 to 10 carbon atoms, specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, Linear alkyl groups such as nonyl and decyl; 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl A branched alkyl group such as a group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom as a substituent, the fluorinated alkyl group preferably has 1 to 11, more preferably 1 to 8, and more preferably 1 to 4 carbon atoms. preferable. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of atoms other than fluorine atoms include oxygen atoms, carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.
Rd ¹ is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted by fluorine atoms, and the hydrogen atom constituting the linear alkyl group It is preferable that all are fluorinated alkyl groups (linear perfluoroalkyl groups) substituted with fluorine atoms.

  Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

(D1-1) Cation part of component:
In formula (d1-1), M ^{m +} is an m-valent organic cation.
As the organic cation of M ^{m +} , those similar to the cations represented by the general formulas (ca-1) to (ca-4) are preferably exemplified, and the formulas (ca-1-1) to (ca Specific examples include cations represented by -1-67).
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

-(D1-2) component (d1-2) Anion part of component:
In formula (d1-2), Rd ² may have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. Examples of the chain alkenyl group include those similar to R ¹⁰¹ in the formula (b-1).
However, a fluorine atom is not bonded to a carbon atom adjacent to the S atom in Rd ² (not fluorine-substituted). Thereby, the anion of (d1-2) component turns into a moderate weak acid anion, and the quenching ability as (D) component improves.
Rd ² is preferably an aliphatic cyclic group which may have a substituent, and a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane or the like. (It may have a substituent); it is more preferably a group obtained by removing one or more hydrogen atoms from camphor or the like.
The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include a hydrocarbon group (aromatic hydrocarbon group, aliphatic hydrocarbon group) in Rd ¹ of the formula (d1-1). The same thing as the substituent which may have is mentioned.

  Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

(D1-2) Cation part of component:
In formula (d1-2), M ^{m +} is an m-valent organic cation, and is the same as M ^{m +} in formula (d1-1).
As the component (d1-2), one type may be used alone, or two or more types may be used in combination.

-(D1-3) component (d1-3) Anion part of component:
In formula (d1-3), Rd ³ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain which may have a substituent. A alkenyl group having the same shape as R ¹⁰¹ in the formula (b-1), and a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. preferable. Among them, a fluorinated alkyl group is preferable, and the same as the fluorinated alkyl group for Rd ¹ is more preferable.

In formula (d1-3), Rd ⁴ may have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. Examples of the chain alkenyl group include those similar to R ¹⁰¹ in the formula (b-1).
Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group which may have a substituent is preferable.
The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group in Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms. Specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n- Examples include butoxy group and tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferable.

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

Examples of the cyclic group for Rd ⁴ include those similar to R ¹⁰¹ in the above formula (b-1), such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group excluding one or more hydrogen atoms, or an aromatic group such as a phenyl group or a naphthyl group is preferred. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in an organic solvent, whereby the lithography properties are improved. In addition, when Rd ⁴ is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition is excellent in light absorption efficiency, and sensitivity and lithography characteristics are good.

In formula (d1-3), Yd ¹ represents a single bond or a divalent linking group.
The divalent linking group in Yd ¹ is not particularly limited, but may be a divalent hydrocarbon group (aliphatic hydrocarbon group or aromatic hydrocarbon group) which may have a substituent, or a hetero atom containing 2 Valent linking groups and the like. Each of these includes a divalent hydrocarbon group which may have a substituent and a hetero atom which are mentioned in the description of the divalent linking group of Ya ²¹ in the formula (a2-1). The thing similar to a valent coupling group is mentioned.
Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is preferably a linear or branched alkylene group, and more preferably a methylene group or an ethylene group.

  Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

(D1-3) Cation part of component:
In formula (d1-3), M ^{m +} is an m-valent organic cation, and is the same as M ^{m +} in formula (d1-1).
As the component (d1-3), one type may be used alone, or two or more types may be used in combination.

As the component (D1), only one of the above components (d1-1) to (d1-3) may be used, or two or more may be used in combination.
Among these, as the component (D1), it is more preferable to use one or more compounds selected from the group consisting of the component (d1-1) and the component (d1-2), and at least the component (d1-2). It is particularly preferable to use
The component (D1) is preferably a component that generates an acid having a pKa that is relatively higher than the acid dissociation constant (pKa) of the acid generated by the exposure of the component (B). Used for. The pKa of the acid generated by exposure of the component (D1) is preferably more than 0, more preferably 1 or more, and further preferably 1-7.

  When the component (d1-2) is used as the component (D1), a compound having a partial structure represented by the following general formula (dr-1) is used particularly from the viewpoint of sensitivity, roughness improvement, and exposure margin. Is also preferable.

［式中、Ｙ^１は２価の連結基である。Ｒ^２及びＲ^３は、それぞれ独立して、フッ素原子ではない炭素数０〜２０の基であり、Ｒ^２又はＲ^３のいずれか一方は、Ｙ^１と環を形成していてもよい。ｍは１以上の整数であって、Ｍ^ｍ＋はｍ価の有機カチオンである。］

[Wherein Y ¹ represents a divalent linking group. R ² and R ³ are each independently a group having 0 to 20 carbon atoms that is not a fluorine atom, and either R ² or R ³ may form a ring with Y ¹ . m is an integer of 1 or more, and M ^{m +} is an m-valent organic cation. ]

In formula (dr-1), Y ¹ represents a divalent linking group.
Preferable examples of the divalent linking group for Y ¹ include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like. Examples thereof are the same as the divalent linking group for Ya ²¹ in 1).
In the resist composition of this embodiment, Y ¹ in the formula (dr-1) may have a substituent except when forming a ring with either R ² or R ³ described later. It is preferably a good divalent hydrocarbon group, more preferably a divalent aliphatic hydrocarbon group which may have a substituent, and a straight chain which may have a substituent or A branched aliphatic hydrocarbon group is more preferable, and a linear or branched alkylene group having 1 to 5 carbon atoms which may have a substituent is particularly preferable.
Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an alkoxy group having 1 to 10 carbon atoms, an alkoxyalkyl group having 2 to 15 carbon atoms, and a carbonyl group. .

In the formula (dr-1), R ² and R ³ are each independently a group having 0 to 20 carbon atoms that is not a fluorine atom, and either R ² or R ³ is Y ^1. And may form a ring. Since R ² and R ³ are not a fluorine atom, the anion portion of the partial structure represented by the formula (dr-1) can be an appropriate weak acid anion.

Examples of the group having 0 to 20 carbon atoms of R ² and R ³ include a hydrogen atom and an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms. For example, methyl group, ethyl group, i-propyl group, t-butyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group , Heptadecyl group, octadecyl group, nonadecyl group, etc.), alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, such as vinyl group, allyl group, 2-butenyl group, 3-pentenyl group, etc.), alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably C2-8, for example, propargyl group, 3-pentynyl group, etc., aryl group (preferably C6-30, more preferably C6-20, particularly preferably C6-12, For example, a phenyl group, p-methylphenyl group, naphthyl group, etc.), a substituted or unsubstituted amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms). For example, an amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamino group, or the like, an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to carbon atoms). For example, methoxy group, ethoxy group, butoxy group, etc.), aryloxy group (preferably having 6 to 20 carbon atoms, more preferably having 6 to 16 carbon atoms, Preferably have 6 to 12 carbon atoms, for example, phenyloxy group, 2-naphthyloxy group, etc., acyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 carbon atom). For example, an acetyl group, a benzoyl group, a formyl group, a pivaloyl group, etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 12 carbon atoms). For example, a methoxycarbonyl group, an ethoxycarbonyl group, etc.), an aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, particularly preferably having 7 to 10 carbon atoms, for example, phenyloxycarbonyl Groups), acyloxy groups (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferred) Has 2 to 10 carbon atoms, for example, an acetoxy group, a benzoyloxy group, etc.), an acylamino group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, For example, acetylamino group, benzoylamino group, etc.), alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino group) ), An aryloxycarbonylamino group (preferably having a carbon number of 7 to 20, more preferably a carbon number of 7 to 16, particularly preferably a carbon number of 7 to 12, such as a phenyloxycarbonylamino group), a sulfonylamino group (preferably Has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 1 carbon atoms. Such as methanesulfonylamino group, benzenesulfonylamino group, etc.), hydroxy group, mercapto group, chlorine atom, bromine atom, iodine atom, cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, A hydrazino group, an imino group, a heterocyclic group (preferably having a carbon number of 1 to 30, more preferably 1 to 12, and examples of the hetero atom include a nitrogen atom, an oxygen atom and a sulfur atom; specifically, for example, imidazolyl, Pyridyl, quinolyl, furyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc., a silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms). For example, trimethylsilyl, triphenylsilyl, etc.) It is done.
When either R ² or R ³ is an alkyl group (preferably a methyl group), one of the hydrogen atoms of the alkyl group is —C (═O) —O—R ¹¹ or —O—C (= O) may be substituted with -R ¹¹ (R ¹¹ is a hydrocarbon group having 4 to 20 carbon atoms which may have a substituent, and in formula (d1-2-1) described later The same as R ¹ ).

When R ² or R ³ is a cyclic hydrocarbon group, it may be an aliphatic group or an aromatic group, may be a polycyclic group, or may be a monocyclic group.
The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. Examples of the monocycloalkane include groups having 3 to 8 carbon atoms, preferably groups having 4 to 8 carbon atoms, and specific examples include cyclopropane, cyclopentane, cyclohexane, and cyclooctane.
The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably a group having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

In the resist composition of this embodiment, the alicyclic hydrocarbon group in R ² and R ³ may contain a hetero atom in the ring structure. Examples of the substituent containing a heteroatom include —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, or —S (═O) ₂ —O—. It is done. Specific examples of the alicyclic hydrocarbon group containing a hetero atom in the ring structure include, for example, the above-described general formulas (a2-r-1) to (a2-r-7), (a5-r-1) to Examples include groups represented by (a5-r-4) and (ax3-r-1) to (ax3-r-3), and are represented by formulas (r-lc-1-1) to (r-lc-1). -2), (r-lc-2-1), (r-lc-2-7), (r-lc-6-1), (r-lc-7-1), (r-sl-1) -1) and groups represented by (r-sl-1-18), respectively.

In the alicyclic hydrocarbon group for R ² and R ^3, a part of the hydrogen atoms bonded to the carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkoxy group, a hydroxyl group, and an oxygen atom (═O).
The alkoxy group of the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and the alkyl group is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Particularly preferred.

In the formula (dr-1), when either R ² or R ³ forms a ring with Y ¹ , the following formula (d- Examples of the group represented by r-2) include groups represented by any of the following formulas (dr-21) to (dr-24).

［式中、Ｙ^１、Ｒ^２及びＲ^３は、前記式（ｄ−ｒ−１）中のＹ^１、Ｒ^２及びＲ^３と同じである。Ｒ^０１〜Ｒ^０４は、炭素数１〜１０の置換基を有していてもよいアルキル基である。ｎは０〜２の整数である。］

^Wherein, Y 1, ^{R 2} and ^{R 3} are the same as ^Y 1, ^{R 2} and ^{R 3} in the formula (d-r-1). R ^{01 to} R ⁰⁴ are an alkyl group which may have a substituent having 1 to 10 carbon atoms. n is an integer of 0-2. ]

The alkyl group which may have a substituent having 1 to 10 carbon atoms in R ^{01 to} R ⁰⁴ is, for example, a methyl group, an ethyl group, an i-propyl group, a t-butyl group, an n-octyl group, an n- Examples include decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, and cyclohexyl group. The substituents that R ^{01 to} R ⁰⁴ may have include a case where the hydrogen atom (—H) in the alkyl group of R ^{01 to} R ⁰⁴ is substituted with a monovalent group, and a methylene group in the alkyl group ( Either of -CH _2- ) may be substituted with a divalent group. Examples of the substituent include imino group, amino group, hydroxy group, mercapto group, halogen atom (for example, chlorine atom, bromine atom, iodine atom), oxygen atom (-O-), cyano group, sulfo group, carboxyl group, nitro group. Groups and the like.

Among the above, R ² and R ³ are each preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, and particularly preferably both R ² and R ³ are hydrogen atoms.

  The specific example of the anion part of the partial structure represented with general formula (dr-1) below is shown.

In the formula (dr-1), m is an integer of 1 or more, and M ^{m +} is an m-valent organic cation.
Examples of the organic cation of M ^{m +} include an onium cation, and a sulfonium cation and an iodonium cation are preferable.
Specific examples of suitable organic cations for M ^{m +} include organic cations represented by the above general formulas (ca-1) to (ca-4), respectively.

  Preferred examples of the compound having a partial structure represented by the general formula (dr-1) include compounds represented by the following general formula (d1-2-1).

［式中、Ｒ^１は置換基を有していてもよい炭素数４〜２０の炭化水素基である。Ｙ^１は２価の連結基である。Ｒ^２及びＲ^３は、それぞれ独立して、フッ素原子ではない炭素数０〜２０の基であり、Ｒ^２又はＲ^３のいずれか一方は、Ｙ^１と環を形成していてもよい。ｍは１以上の整数であって、Ｍ^ｍ＋はｍ価の有機カチオンである。］

[Wherein, R ¹ represents a hydrocarbon group having 4 to 20 carbon atoms which may have a substituent. Y ¹ is a divalent linking group. R ² and R ³ are each independently a group having 0 to 20 carbon atoms that is not a fluorine atom, and either R ² or R ³ may form a ring with Y ¹ . m is an integer of 1 or more, and M ^{m +} is an m-valent organic cation. ]

Wherein (d1-2-1), ^{M m +} is an organic cation having a valency of m, it is the same as the ^{M m +} in the formula (d-r-1). Especially, the cation part [(M ^{m +} ) _{1 / m} ] is preferably an organic cation represented by the general formula (ca-1), and each represented by the formulas (ca-1-1) to (ca-1-67). The represented cation is more preferred.

In said formula (d1-2-1), R < ¹ > is a C4-C20 hydrocarbon group which may have a substituent. The hydrocarbon group for R ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
Examples of the hydrocarbon group for R ¹ include a linear or branched alkyl group or a cyclic hydrocarbon group.

The linear or branched alkyl group in the hydrocarbon group for R ¹ preferably has 4 to 20 carbon atoms, and specifically includes an n-butyl group, an isobutyl group, a tert-butyl group, and pentyl. Group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undekyl group, dodekyl group, tridekyl group, tetradekyl group, pentadekyl group, hexadekyl group, heptadekyl group, octadekyl group, nonadekyl group, Examples include 1,1-dimethylethyl group, 1,1-diethylpropyl group, 2,2-dimethylpropyl group, 2,2, -dimethylbutyl group and the like.

The cyclic hydrocarbon group in the hydrocarbon group for R ¹ may be an aliphatic group or an aromatic group, may be a polycyclic group, or may be a monocyclic group.
The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane is preferably a group having 4 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane, cyclooctane and the like. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably a group having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

Moreover, the said alicyclic hydrocarbon group in R < ¹ > may contain the hetero atom in the ring structure. Examples of the substituent containing a heteroatom include —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, or —S (═O) ₂ —O—. It is done.
Specific examples of the alicyclic group containing a hetero atom in the ring structure include, for example, the general formulas (a2-r-1) to (a2-r-7) and (a5-r-1) to (a5). -R-4), groups represented by (ax3-r-1) to (ax3-r-3), or specific examples thereof, and the above formulas (r-lc-1-1) to (R-lc-1-2), (r-lc-2-1), (r-lc-2-7), (r-lc-6-1), (r-lc-7-1), Groups represented by (r-sl-1-1) and (r-sl-1-18) are preferred.

When R ¹ is an aromatic hydrocarbon group, specific examples of the aromatic ring contained include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; An aromatic heterocyclic ring in which a part of carbon atoms is substituted with a hetero atom is exemplified. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group); a group in which one of the hydrogen atoms of the aryl group is substituted with an alkylene group (for example, Benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group) and the like. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

The substituent which R ¹ may have is an amino group, —C (═O) —R ″ ¹ group, —O—C (═O) —R ″ ¹ group (R ″ ¹ is 1 to ¹ carbon atoms) 5 alkyl group), alkyl group, alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, oxo group (═O) and the like, amino group, —O—C (═O) —R ″ ¹ group, A polar group such as a hydroxyl group or an oxo group is preferable because lithography properties and the like are improved.
The alkyl group as the substituent 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.
The alkoxy group as the substituent 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. An ethoxy group is more preferable.
Examples of the halogen atom as the substituent 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 include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

R ¹ is preferably an aliphatic hydrocarbon group having 4 to 20 carbon atoms which may have a substituent, from the viewpoint that sensitivity, EL margin, lithography properties such as LWR, etc. are further improved. In terms of sensitivity and lithographic properties, among the above formulas (r-lc-1-1) to (r-lc-1-2), (r-lc-2-1), (r-lc-2-) 7), groups represented by (r-lc-6-1), (r-lc-7-1), (r-sl-1-1), (r-sl-1-18), More preferably, it is an aliphatic hydrocarbon group having the polar group as a group, or a monocyclic or polycyclic alicyclic hydrocarbon group which may have a substituent.

In the formula ^{(d1-2-1), Y 1, R} 2 and ^{R 3} are each same as ^Y 1, ^{R 2} and ^{R 3} in the formula (d-r-1).
In Formula (d1-2-1), Y ¹ is preferably a linear or branched aliphatic hydrocarbon group which may have a substituent, and is a straight chain having 1 to 5 carbon atoms. It is more preferably a chain or branched alkylene group.
In the formula (d1-2-1), R ² and R ³ are each preferably a hydrogen atom, and both R ² and R ³ are particularly preferably hydrogen atoms.

Below, the preferable specific example of a compound represented by general formula (d1-2-1) is shown. Further, in the following specific examples, the structure of a portion other than R ¹ may also include those that have a structure example of the anion moiety of the partial structure represented by the above general formula (d-r-1).
In the following chemical formula, M ^{m +} is an m-valent organic cation and is the same as M ^{m +} in the formula (d1-2-1).

In the resist composition of this embodiment, the content of the component (D1) is preferably 0.5 to 10 parts by mass, and 0.5 to 8 parts by mass with respect to 100 parts by mass of the component (A). Is more preferable, and it is further more preferable that it is 1-8 mass parts.
When the content of the component (D1) is equal to or more than the preferable lower limit value, good lithography characteristics and a resist pattern shape such as improvement of roughness can be obtained. On the other hand, when it is at most the preferable upper limit value, the sensitivity can be maintained satisfactorily and the throughput is also excellent.

-Manufacturing method of (D1) component The manufacturing method of said (d1-1) component and (d1-2) component is not specifically limited, It can manufacture by a well-known method.
Moreover, the manufacturing method of (d1-3) component is not specifically limited, For example, it manufactures similarly to the method of US2012-0149916 gazette.

In the present invention, the “molar ratio represented by (D1) / (B)” means the mixing ratio of the component (B) and the component (D1) contained in the resist composition, that is, the content of the component (B). The ratio (molar ratio) of the content of the component (D1) with respect to is shown.
In the resist composition of this embodiment, the mixing ratio of the acid generator component (B) and the photodegradable base (D1) is a molar ratio represented by (D1) / (B) (hereinafter referred to as “(D1) / ( B) ratio ”) is preferably 0.4 or more, more preferably 0.5 or more, still more preferably 0.6 or more, and particularly preferably 0.6 to 1.7. Most preferably, it is 0.6 to 1.65.
When the ratio (D1) / (B) is equal to or greater than the preferable lower limit, the roughness of the resist pattern is excellent. In addition, the exposure margin (EL margin) is easily improved. On the other hand, when the (D1) / (B) ratio is equal to or less than the preferable upper limit value, the sensitivity is further increased.

<Other ingredients>
The resist composition of this embodiment may further contain other components in addition to the components (A), (B) and (D1).

[(D2) component]
Examples of such other components include nitrogen-containing organic compound components (hereinafter referred to as “(D2) component”) that do not correspond to the component (D1).
The component (D2) is not particularly limited as long as it functions as an acid diffusion controller and does not correspond to the component (D1), and any known component may be used. Of these, aliphatic amines, and particularly, secondary aliphatic amines and tertiary aliphatic amines are preferable.
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 , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol 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 or tri-n-octylamine is 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.

  Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2 -(1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxy Ethoxy) ethoxy} ethyl] amine, triethanolamine triacetate and the like, and triethanolamine triacetate is preferable.

As the component (D2), an aromatic amine may be used.
Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine and the like.

(D2) A component may be used independently and may be used in combination of 2 or more type.
When the component (D2) is used, the component (D2) is usually used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A). 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 this embodiment comprises an organic carboxylic acid, and an oxo acid of phosphorus and its derivatives as optional components for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention time stability, etc. 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 phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
When (E) component is used, (E) component is normally used in 0.01-5 mass parts with respect to 100 mass parts of (A) component.

[(F) component]
The resist composition of this embodiment may contain a fluorine additive (hereinafter referred to as “component (F)”) in order to impart water repellency to the resist film.
Examples of the component (F) include those described in JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, and JP 2011-128226 A. These fluorine-containing polymer compounds can be used.
More specifically, examples of the component (F) include a polymer having a structural unit (f1) represented by the following formula (f1-1). Examples of the polymer include a polymer (homopolymer) composed only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1). A copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate.

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

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

In formula (f1-1), R bonded to the α-position carbon atom is the same as described above. R is preferably a hydrogen atom or a methyl group.
In formula (f1-1), examples of the halogen atom for Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. Examples of the alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ include the same as the alkyl group having 1 to 5 carbon atoms of R, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ include a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. Can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. The inter alia ^{Rf 102} and ^{Rf 103,} a hydrogen atom, a fluorine atom, or an alkyl group of 1 to 5 carbon atoms is preferable, a hydrogen atom, a fluorine atom, a methyl group or an ethyl group, preferred.
In formula (f1-1), nf ¹ is an integer of ¹ to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms. The carbon number of 1 to 10 is particularly preferable.
The hydrocarbon group containing a fluorine atom preferably has 25% or more of the hydrogen atoms in the hydrocarbon group fluorinated, more preferably 50% or more fluorinated, and 60% or more. Fluorination is particularly preferable because the hydrophobicity of the resist film during immersion exposure is increased.
Among ^these, as ^{Rf 101,} particularly preferably a fluorinated hydrocarbon group having 1 to 5 carbon atoms, a trifluoromethyl _{group, -CH 2 -CF 3, -CH 2} -CF 2 -CF 3, -CH (CF 3 ) ₂ , —CH ₂ —CH ₂ —CF ₃ , —CH ₂ —CH ₂ —CF ₂ —CF ₂ —CF ₂ —CF ₃ are most preferred.

(F) As for the mass mean molecular weight (Mw) (polystyrene conversion reference | standard by a gel permeation chromatography), 1000-50000 are preferable, 5000-40000 are more preferable, and 10000-30000 are the most preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw / Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

(F) A component may be used individually by 1 type and may use 2 or more types together.
When the component (F) is used, the component (F) is preferably used at a ratio of 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

  The resist composition of the present embodiment further contains an optional miscible additive such as an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, A dye or the like can be appropriately added and contained.

[(S) component]
The resist composition of this embodiment can be produced by dissolving a resist material in an organic solvent (hereinafter sometimes 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 (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol Polyhydric alcohols such as: ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, etc., compounds having an ester bond, monohydric ethers of the polyhydric alcohols or compounds having an ester bond , Monoalkyl ethers such as monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond [in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and lactic acid Esters such as methyl, 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, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. An aromatic organic solvent, dimethyl sulfoxide (DMSO), etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone 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 or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA: EL or cyclohexanone 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. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferable.
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.
(S) The usage-amount of a component is not specifically limited, It is a density | concentration which can be apply | coated to a board | substrate etc., and is suitably set according to a coating film thickness. Generally, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

According to the resist composition of the present invention, a resist pattern with reduced roughness can be formed.
The resist composition of the present invention contains a polymer compound (A1) having a structural unit (a0) containing a lactone-containing cyclic group having an electron-withdrawing substituent (X). By using the component (A1), when forming a resist pattern, a decrease in sensitivity is suppressed and good sensitivity is maintained. In addition, by having the structural unit (a0), the solubility of the component (A1) in the organic solvent is increased, and it can be stably dissolved in the resist solvent.
In addition, the resist composition of the present invention contains a quencher composed of an acid generator (B) and a compound (D1) having a specific anion moiety. By this quencher, the diffusion of the acid generated from the component (B) by exposure is moderately suppressed, and the contrast between the exposed portion and the unexposed portion of the resist film is further improved.
In the resist composition of the present invention, the combination of the (A1) component having the structural unit (a0), the (B) component, and the (D1) component has a remarkable effect of reducing roughness when forming a resist pattern. can get. In addition, according to the resist composition of the present invention, it is possible to form a resist pattern with reduced roughness while maintaining better sensitivity. Further, in resist pattern formation using the resist composition of the present invention, an exposure margin (EL margin), which is an index of the amount of change in the pattern size associated with the variation in exposure amount, which is difficult to achieve both reduction in roughness. Is also good.

≪Resist pattern formation method≫
The resist pattern forming method of the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition of the first aspect of the present invention, a step of exposing the resist film, and the A step of developing the resist film after exposure to form a resist pattern.
The resist pattern forming method of this aspect can be performed as follows, for example.
First, the resist composition according to the first aspect is applied onto a support with a spinner or the like, and baking (post-apply bake (PAB)) treatment is performed at a temperature of 80 to 150 ° C. for 40 to 120 seconds, for example. The resist film is formed preferably for 60 to 90 seconds.
Next, exposure or a mask pattern is performed on the resist film through a mask (mask pattern) on which a predetermined pattern is formed using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus. After performing selective exposure by drawing or the like by direct irradiation of an electron beam without passing through, baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to Apply for 90 seconds.
Next, the resist film is developed. The development treatment is performed using an alkaline developer in the case of an alkali development process, and using a developer (organic developer) containing an organic solvent in the case of a solvent development process.
A rinsing treatment is preferably performed after the development treatment. The rinse treatment is preferably a water rinse using pure water in the case of an alkali development process, and is preferably a rinse solution containing an organic solvent in the case of a solvent development process.
In the case of a solvent development process, after the development process or the rinse process, a process of removing the developer or rinse liquid adhering to the pattern with a supercritical fluid may be performed.
Drying is performed after development or rinsing. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist 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 organic films such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the resist pattern formed on the upper resist film is used as a mask. This is a method of patterning a lower organic film, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
In the multilayer resist method, basically, a method of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower organic film And a method of forming a multilayer structure of three or more layers (metal thin film etc.) (three-layer resist method).

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 is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV, and is particularly useful for ArF excimer laser, EB or EUV.

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

Examples of the alkali developer used for the development treatment in the alkali development process include a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for the development process in the solvent development process is not particularly limited as long as it can dissolve the component (A) (component (A) before exposure). It can be selected as appropriate. Specific examples include ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, ether solvents, and other polar solvents, hydrocarbon solvents, and the like.
The ketone solvent is an organic solvent containing C—C (═O) —C in the structure. The ester solvent is an organic solvent containing C—C (═O) —O—C in the structure. The alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and “alcoholic hydroxyl group” means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. A nitrile solvent is an organic solvent containing a nitrile group in its structure. The amide solvent is an organic solvent containing an amide group in the structure. The ether solvent is an organic solvent containing C—O—C in the structure.
Among organic solvents, there are organic solvents that contain multiple types of functional groups that characterize each of the above solvents in the structure, but in that case, any of the solvent types that contain the functional groups of the organic solvent is applicable. Shall. For example, diethylene glycol monomethyl ether shall correspond to both of the alcohol solvent and the ether solvent in the above classification.
The hydrocarbon solvent is a hydrocarbon solvent made of a hydrocarbon which may be halogenated and having no substituent other than a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Among the above, the organic solvent contained in the organic developer is preferably a polar solvent, and is preferably a ketone solvent, an ester solvent, a nitrile solvent, or the like.

Specific examples of each solvent include ketone solvents such as 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, Methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetylalcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, propylene carbonate, γ-butyrolactone, methylamylketone (2- Heptanone) and the like.
As the ketone solvent, methyl amyl ketone (2-heptanone) is preferable.

Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene Recall monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, Propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxy Nethyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, pyrubin Methyl acid, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, 2-hydroxypropionate Examples include ethyl acid, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.
As the ester solvent, butyl acetate is preferred.

  Examples of the nitrile solvent include acetonitrile, propionitryl, valeronitrile, butyronitryl and the like.

A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. The surfactant is not particularly limited. For example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used. As the surfactant, a nonionic surfactant is preferable, and a fluorine-based surfactant or a silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0. 0% with respect to the total amount of the organic developer. 5 mass% is more preferable.

  The development process can be performed by a known development method. For example, a method in which a support is immersed in a developer for a certain period of time (dip method), a developer is raised on the surface of the support by surface tension, and is left for a certain period of time. (Paddle method), spraying developer on the surface of the support (spray method), coating the developer while scanning the developer coating nozzle at a constant speed on the support rotating at a constant speed The method of continuing (dynamic dispensing method) etc. are mentioned.

As the organic solvent contained in the rinsing liquid used for the rinsing process after the development process in the solvent developing process, for example, an organic solvent that is difficult to dissolve the resist pattern is selected as appropriate from the organic solvents used as the organic solvent used in the organic developer. Can be used. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
The alcohol solvent used for the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. It is done. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use the organic solvent and water other than the above. However, in consideration of development characteristics, the blending amount of water in the rinsing liquid is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, more preferably 3% by mass or less based on the total amount of the rinsing liquid. Is particularly preferred.
A well-known additive can be mix | blended with a rinse liquid as needed. Examples of the additive include a surfactant. Examples of the surfactant are the same as those described above, and a nonionic surfactant is preferable, and a fluorine-based surfactant or a silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.5% by mass with respect to the total amount of the rinse liquid. % Is more preferable.

  The rinse treatment (washing treatment) using the rinse liquid can be performed by a known rinse method. Examples of the method include a method of continuously applying a rinsing liquid on a support rotating at a constant speed (rotary coating method), a method of immersing the support in a rinsing liquid for a predetermined time (dip method), and the surface of the support. And a method of spraying a rinse liquid (spray method).

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

<Production example of polymer compound>
The polymer compound used as the substrate component in this example was obtained by using a compound represented by the following chemical formula as a monomer in combination at a predetermined molar ratio and copolymerizing by a known radical polymerization method.

(Polymer compounds 1-6)
About the obtained high molecular compounds 1-6, the monomer composition ratio (ratio (molar ratio) of each structural unit in a structure) of this high molecular compound calculated | required by ¹³ C-NMR, standard polystyrene conversion calculated | required by GPC measurement Table 1 shows the mass average molecular weight (Mw) and the molecular weight dispersity (Mw / Mn).

<Preparation of resist composition>
(Examples 1-18, Comparative Examples 1-4)
The resist composition of each example was prepared by mixing and dissolving each component shown in Table 2. However, Example 1, Example 5, Example 8, Examples 11-14, and Examples 16-18 are reference examples.

In Table 2, each abbreviation has the following meaning. The numerical value in [] is a compounding amount (part by mass).
“(D) / (B) molar ratio” is a mixing ratio of the component (B) and the component (D) (the component (D1) or the component (D2)) contained in the resist composition, that is, (B ) The content ratio (molar ratio) of the component (D) to the content of the component.
(A) -1 to (A) -6: The above polymer compounds 1 to 6.
(B) -1: An acid generator composed of a compound represented by the following chemical formula (B) -1.
(D1) -1 to (D1) -5: Compounds represented by the following chemical formulas (D1) -1 to (D1) -5, respectively.
(D2) -1: Tripentylamine.
(D2) -2: 2,4-diisopropylaniline.
(F) -1: A fluorine-containing polymer compound represented by the following chemical formula (F) -1. The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 25000, and the molecular weight dispersity (Mw / Mn) is 2.0.
(S) -1: Mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / cyclohexanone = 45/30/25 (mass ratio).

  A resist pattern was formed using the obtained resist composition, and each evaluation of sensitivity, line width roughness (LWR), and exposure margin (EL margin) was performed as follows.

<Formation of resist pattern>
An organic antireflective coating composition “ARC95” (trade name, manufactured by Brewer Science) is applied onto a 12-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a thickness of 90 nm was formed.
Next, the resist composition of each example is applied onto the organic antireflection film using a spinner, and prebaked (PAB) at a temperature of 110 ° C. for 60 seconds on a hot plate and dried. Thus, a resist film having a thickness of 90 nm was formed.
Next, an immersion ArF exposure apparatus NSR-S609B [manufactured by Nikon; NA (numerical aperture) = 1.07, Dipole 0.97 / 0.78 with polano, immersion medium: water] is applied to the resist film. ArF excimer laser (193 nm) was selectively irradiated through a binary mask.
Thereafter, a post-exposure heating (PEB) treatment at a temperature of 95 ° C. for 60 seconds was performed.
Next, alkali development is performed for 10 seconds with a 2.38 mass% TMAH aqueous solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C., and then water rinse for 30 seconds using pure water. Then, it was shaken and dried.
As a result, in each example, a 1: 1 line and space (LS) pattern having a line width of 50 nm and a pitch of 100 nm was formed.
In the formation of the resist pattern in each example, the optimum exposure amount (sensitivity) Eop (mJ / cm ² ) at which the LS pattern was formed was determined. The results are shown in Table 3.

[Evaluation of line width roughness (LWR)]
In the LS pattern formed by the above <resist pattern formation>, the length of the space was measured with a length measurement SEM (scanning electron microscope, acceleration voltage 300 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation) 400 points were measured in the direction, and the standard deviation (s) was tripled (3 s) from the result, and the value (nm) averaged over 400 s 3s was calculated as a measure of LWR. The results are shown in Table 3.
A smaller value of 3s means that the roughness of the line width is smaller, and an LS pattern having a more uniform width is obtained.

[Evaluation of exposure margin (EL margin)]
The exposure amount when the line of the LS pattern is formed within a range of ± 5% (47.5 nm to 52.5 nm) of the target dimension (line width 50 nm) by the above <resist pattern formation> is obtained by the following formula: The EL margin (unit:%) was determined. The results are shown in Table 3.
EL margin (%) = (| E1-E2 | / Eop) × 100
E1: Exposure amount (mJ / cm ² ) when an LS pattern having a line width of 47.5 nm was formed
E2: exposure amount (mJ / cm ² ) when an LS pattern having a line width of 52.5 nm was formed
The EL margin indicates that the larger the value is, the smaller the change amount of the pattern size with the variation of the exposure amount.

  From the results shown in Table 3, it can be confirmed that by using the resist compositions of Examples 1 to 18 to which the present invention is applied, a resist pattern with reduced roughness can be formed.

Claims (5)

Forming a resist film on a support using a resist composition; exposing the resist film; and developing the exposed resist film with an alkaline developer to form a positive resist pattern. A positive resist composition used in a resist pattern forming method,
It is a resist composition that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid.
A base component (A) whose solubility in an alkaline developer is increased by the action of an acid;
An acid generator component (B) that generates an acid upon exposure; and
A compound represented by the following general formula (d1-1), and the general formula (d1-2) compound represented by either Ranaru one or more compounds selected from the group and (D1),
Containing
Base material component (A), structural units represented by the following general formula (a0-1) (a0), and lactone-containing cyclic group, -SO ₂ - containing cyclic group, or a carbonate-containing cyclic group Containing structural unit (a2) (however, except for the structural unit (a0), when the structural unit (a2) includes a lactone-containing cyclic group, the following general formula (a2-r-1), (a2 -R-2), (a2-r-3), (a2-r-4), (a2-r-5), and (a2-r-7) represented by the general formula selected from the group consisting of A polymer compound (A1) having a lactone-containing cyclic group located at the side chain terminal of the polymer compound (A1),
The acid generator component (B) includes a compound represented by the following general formula (b-1),
The resist composition characterized in that the molar ratio represented by (D1) / (B), which indicates the mixing ratio of the acid generator component (B) and the compound (D1), is 0.5 or more. .

[Wherein Rd ¹ and Rd ² are a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain which may have a substituent. Of the alkenyl group. However, a fluorine atom is not bonded to a carbon atom adjacent to the S atom in Rd ² in the formula (d1-2) . m is an integer of 1 or more, and M ^{m +} is each independently an m-valent organic cation. ]

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Va ⁰ is a divalent hydrocarbon group which may have a substituent. _na0 is an integer of 0-2. Ra ¹ and Ra ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or an alkylthio group, or Ra ¹ and Ra ² are bonded to each other to form an oxygen atom (—O -) Or a C1-C6 alkylene group which may contain a sulfur atom (-S-), an ether bond, or a thioether bond. Ra ′ ⁰¹ may have a halogen atom, an alkyl group having 1 to 6 carbon atoms, and the hydroxy group portion may be protected with a protecting group and may have a halogen atom. A hydroxyalkyl group, a carboxy group forming a salt, or a substituted oxycarbonyl group. When two or more Ra ′ ⁰¹ are present, the plurality of Ra ′ ⁰¹ may be the same as or different from each other. X is a substituent selected from the group consisting of a halogen atom, a carboxy group, an acyl group, a nitro group, and a cyano group. When two or more X are present, the plurality of X may be the same as or different from each other. p ₀ is an integer of 0-8. q ₀ is an integer of 1 to 9. ]

[Wherein, Ra ′ ²¹ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group; A ″ is an oxygen atom (—O—) or a sulfur atom (— S—) may be an alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom, n ′ is an integer of 0 to 2, and m ′ is 0 or 1. * Indicates a bond. ]

[Wherein, R ¹⁰¹ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. It is. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a divalent linking group containing an oxygen atom. V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. m is an integer of 1 or more, and M ′ ^{m +} is an m-valent onium cation. ]   The resist composition according to claim 1, wherein the polymer compound (A1) has a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid. X in the above general formula (a0-1) is a cyano group, a resist composition according to claim 1 or 2. The said compound (D1) is a resist composition as described in any one of Claims 1-3 containing the compound represented by the said general formula (d1-2). Forming a resist film on a substrate using the resist composition according to any one of claims 1-4, exposing the resist film, and the resist film after the exposure with an alkali developer A resist pattern forming method including a step of developing to form a positive resist pattern.