JP2014152122A - Compound, polymeric compound, resist composition and method for forming resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound that is useful for improving lithography characteristics, a polymeric compound derived from the compound, a resist composition comprising the polymeric compound, and a method for forming a pattern.SOLUTION: The compound is expressed by general formula (a0-1) below. In the formula, Rrepresents H or an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Yand Yrepresent a single bond or a divalent connecting group; Rand Rrepresent a functional group or a group expressed by formula (1-an1), (1-an2) or (1-an3); n1 represents an integer of 0 to 2; n2 represents 0 or 1; Y1 represents a single bond or -SO-; Rrepresents a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent; and Xrepresents an organic cation or a metal cation.

Description

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

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 a solvent development process using a developer containing an organic solvent (organic developer) is applied, the solubility in the organic developer is relatively lowered when the polarity of the base resin is increased. The unexposed portion is dissolved and removed by the organic developer, and a negative resist pattern is formed in which the exposed portion remains as a pattern. Such a solvent development process for forming a negative resist pattern is sometimes referred to as a negative development process (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. However, other structural units including a lactone-containing cyclic group, structural units including a polar group such as a hydroxyl group, and the like are used (for example, see Patent Document 2).
Further, as the base resin, -SO 2 _- as a structural unit containing a cyclic group containing structure has been proposed. Such a base resin is said to contribute to the improvement of resist pattern shape such as lithography characteristics such as mask reproducibility and roughness reduction. Roughness means a rough surface of the resist pattern and causes a defective shape of the resist pattern. For example, line width roughness (line width roughness (LWR)) causes a shape defect typified by non-uniform line width in a line-and-space pattern. The defective shape of the resist pattern may adversely affect the formation of a fine semiconductor element, and the improvement becomes more important as the pattern becomes finer.

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.
In contrast, Patent Document 3 proposes a resin having an acid generating group that decomposes upon exposure to generate an acid. In the invention described in Patent Document 3, a monomer having a structural unit that generates an acid upon exposure, a monomer having a structural unit that includes a cyclic group that includes a —SO ₂ — structure, and a polarity decomposed by the action of an acid. As a base resin, a polymer compound obtained by copolymerizing a monomer having a structural unit containing an acid-decomposable group increasing in the number of units is used.
Such a resin has both a function as an acid generator and a function as a base component, and can constitute a chemically amplified resist composition with one component.

JP 2009-025723 A JP 2003-241385 A JP 2011-158879 A

Along with further progress in lithography technology and expansion of application fields, improvement of various lithography characteristics is further required in the formation of resist patterns.
For example, as the pattern becomes finer, conventional resist materials such as a resist material using the base resin described in Patent Document 3 have not only sensitivity and resolution, but also roughness (LWR ( In the case of a hole pattern, such as line width roughness (line width non-uniformity), in-plane uniformity, roundness, etc.), mask reproducibility, exposure margins, and other various lithography properties must be further improved. .

  An object of the present invention is to provide a compound useful for a resist composition capable of improving lithography properties, a polymer compound derived from the compound, a resist composition containing the polymer compound, and a pattern forming method. And

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 “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which part or all of the hydrogen atoms of an alkyl group or alkylene group are substituted with fluorine atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid 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 ^α ) 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. Examples thereof include an alkyl group and a hydroxyalkyl group. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
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”.
“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. The derivatives include those in which the hydrogen atom at the α-position may be substituted with a substituent, the hydrogen atom of the hydroxyl group of hydroxystyrene substituted with an organic group, and the hydrogen atom at the α-position substituted with a substituent. Examples include those in which a substituent other than a hydroxyl group is bonded to a good benzene ring of hydroxystyrene. 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 obtained by substituting the hydrogen atom of the carboxy group of vinyl benzoic acid with an organic group, which may be substituted with a hydrogen atom at the α-position, and the hydrogen atom at the α-position 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.
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 Including both.
“Exposure” is a concept including general irradiation of radiation.

  The first aspect of the present invention is a compound represented by the following general formula (a0-1).

［式中、Ｒ^１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り、Ｙ^２及びＹ^３はそれぞれ独立に、単結合または２価の連結基であり、Ｒ^２及びＲ^３はそれぞれ独立に、機能性基、または一般式（１−ａｎ１）、（１−ａｎ２）若しくは（１−ａｎ３）で表される基であって、Ｒ^２又はＲ^３の少なくとも一方は一般式（１−ａｎ１）、（１−ａｎ２）または（１−ａｎ３）で表される基である。ｎ１は、０〜２の整数である。ｎ２は０または１である。
Ｙ¹は単結合または−ＳＯ_２−であり、Ｒ^５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、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。Ｘ^＋は有機カチオンまたは金属カチオンである。］

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ² and Y ³ are each independently a single bond or a divalent linking group. R ² and R ³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ² or R 3 ^At least one of ³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n1 is an integer of 0-2. n2 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. X ⁺ is an organic cation or a metal cation. ]

  The second aspect of the present invention is a polymer compound having a structural unit (a0) derived from a compound represented by the following general formula (a0-1).

［式中、Ｒ^１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り、Ｙ^２及びＹ^３はそれぞれ独立に、単結合または２価の連結基であり、Ｒ^２及びＲ^３はそれぞれ独立に、機能性基、または一般式（１−ａｎ１）、（１−ａｎ２）若しくは（１−ａｎ３）で表される基であって、Ｒ^２又はＲ^３の少なくとも一方は一般式（１−ａｎ１）、（１−ａｎ２）または（１−ａｎ３）で表される基である。ｎ１は、０〜２の整数である。ｎ２は０または１である。
Ｙ¹は単結合または−ＳＯ_２−であり、Ｒ^５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、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。Ｘ^＋は有機カチオンまたは金属カチオンである。］

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ² and Y ³ are each independently a single bond or a divalent linking group. R ² and R ³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ² or R 3 ^At least one of ³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n1 is an integer of 0-2. n2 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. X ⁺ is an organic cation or a metal cation. ]

  According to a third aspect of the present invention, there is provided a resist composition that generates an acid upon exposure and changes its solubility in a developing solution by the action of an acid, wherein the solubility of the developing solution is changed by the action of an acid. A polymer compound (A1 ′) containing a component (A ′), wherein the substrate component (A ′) has a structural unit (a0) derived from a compound represented by the following general formula (a0-11) It is a resist composition characterized by containing.

［式中、Ｒ^１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り、Ｙ^２及びＹ^３はそれぞれ独立に、単結合または２価の連結基であり、Ｒ^２及びＲ^３はそれぞれ独立に、機能性基、または一般式（１−ａｎ１）、（１−ａｎ２）若しくは（１−ａｎ３）で表される基であって、Ｒ^２又はＲ^３の少なくとも一方は一般式（１−ａｎ１）、（１−ａｎ２）または（１−ａｎ３）で表される基である。ｎ１は、０〜２の整数である。ｎ２は０または１である。Ｙ¹は単結合または−ＳＯ_２−であり、Ｒ^５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、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。Ｘ^＋は有機カチオンまたは金属カチオンである。］

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ² and Y ³ are each independently a single bond or a divalent linking group. R ² and R ³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ² or R 3 ^At least one of ³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n1 is an integer of 0-2. n2 is 0 or 1. Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. X ⁺ is an organic cation or a metal cation. ]

  A fourth aspect of the present invention is a resist composition containing a base component (A) whose solubility in a developer is changed by the action of an acid, and an acid generator component (B ′) that generates an acid upon exposure. The acid generator component (B ′) is a resist composition containing an acid generator (B1 ′) containing a compound represented by the following general formula (a0-11).

［式中、Ｒ^１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り、Ｙ^２及びＹ^３はそれぞれ独立に、単結合または２価の連結基であり、Ｒ^２及びＲ^３はそれぞれ独立に、機能性基、または一般式（１−ａｎ１）、（１−ａｎ２）若しくは（１−ａｎ３）で表される基であって、Ｒ^２又はＲ^３の少なくとも一方は一般式（１−ａｎ１）、（１−ａｎ２）または（１−ａｎ３）で表される基である。ｎ１は、０〜２の整数である。ｎ２は０または１である。
Ｙ¹は単結合または−ＳＯ_２−であり、Ｒ^５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、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。Ｘ^＋は有機カチオンまたは金属カチオンである。］

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ² and Y ³ are each independently a single bond or a divalent linking group. R ² and R ³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ² or R 3 ^At least one of ³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n1 is an integer of 0-2. n2 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. X ⁺ is an organic cation or a metal cation. ]

  According to a fifth aspect of the present invention, a resist film is formed on a support using the third or fourth resist composition, the resist film is exposed, and the resist film is developed to form a resist. It is a resist pattern formation method including the process of forming a pattern.

  According to the present invention, there are provided a compound useful for a resist composition capable of improving lithography properties, a polymer compound derived from the compound, a resist composition containing the polymer compound, and a pattern forming method. Can do.

≪Compound≫
The first aspect of the present invention is a compound represented by the following general formula (a0-1).

［式中、Ｒ^１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り、Ｙ^２及びＹ^３はそれぞれ独立に、単結合または２価の連結基であり、Ｒ^２及びＲ^３はそれぞれ独立に、機能性基、または一般式（１−ａｎ１）、（１−ａｎ２）若しくは（１−ａｎ３）で表される基であって、Ｒ^２又はＲ^３の少なくとも一方は一般式（１−ａｎ１）、（１−ａｎ２）または（１−ａｎ３）で表される基である。ｎ１は、０〜２の整数である。ｎ２は０または１である。
Ｙ¹は単結合または−ＳＯ_２−であり、Ｒ^５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、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。Ｘ^＋は有機カチオンまたは金属カチオンである。］

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ² and Y ³ are each independently a single bond or a divalent linking group. R ² and R ³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ² or R 3 ^At least one of ³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n1 is an integer of 0-2. n2 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. X ⁺ is an organic cation or a metal cation. ]

In formula (a0-1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, or an 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 ¹ 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 formula (a0-1), Y ² and Y ³ are each independently a single bond or a divalent linking group.
Although it does not specifically limit as a bivalent coupling group, The bivalent hydrocarbon group which may have a substituent, the bivalent coupling group containing a hetero atom, etc. are mentioned as a suitable thing.

(Divalent hydrocarbon group which may have a substituent)
The hydrocarbon group as the divalent linking group 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 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. The group illustrated by Va ¹ in 1) is mentioned.

  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.

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 (excluding two hydrogen atoms from the aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched chain fatty acid. Group intervening in the middle of the group 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.
Specific examples of the cyclic aliphatic hydrocarbon group include groups exemplified by Va ¹ in the formula (a1-1) described later.
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.

Specific examples of the aromatic hydrocarbon group as the divalent hydrocarbon group include a group exemplified by Va ¹ in the formula (a1-1) described later.
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.

(Divalent linking group containing a hetero atom)
The hetero atom in the divalent linking group containing a hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

When Y ² and Y ³ are a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C (═O) —O—, —C (═O) —, — O—C (═O) —O—, —C (═O) —NH—, —NH—, —NH—C (═NH) — (H is substituted with a substituent such as an alkyl group or an acyl group. and may _{be), -. S -, -} S (= O) 2 -, - S (= O) 2 -O-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y ²¹ —C (═O) —O—, — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (═O) —Y ²² — Wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m ′ is an integer of 0 to 3. is there. ] Etc. are mentioned.
When the divalent linking group containing a hetero atom is —C (═O) —NH—, —NH—, —NH—C (═NH) —, H is a substituent such as an alkyl group or acyl. May be substituted. 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 -, - [Y 21 -C (= O) -O] m '-Y 22 - or ^{-Y 21 -O-C (= O} ) -Y 22 - ^{in, Y 21} and ^{Y 22} are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include those similar to the “divalent hydrocarbon group optionally having substituent (s)” mentioned in the description of the divalent linking group.
Y ² and Y ³ are each independently 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, A methylene group or an ethylene group is particularly preferred.
Y ² and Y ³ are each independently 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 —. The group is particularly preferred. Among these, a group represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} — is preferable. In the formula, a ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 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.

Y ² and Y ³ in the present invention are each independently a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), a linear or branched alkylene. Group, a linear or branched alkylene group substituted with a fluorine atom, a cyclic aliphatic hydrocarbon group which may have a substituent, an arylene group which may have a substituent, a substituent It is preferably a group obtained by removing one hydrogen atom from an aryl group in the arylalkyl group which may have a single bond or an ester bond [—C (═O) —O— ], An ether bond (—O—), a linear or branched alkylene group, a linear or branched alkylene group substituted with a fluorine atom, or a combination thereof is more preferable.

In formula, n1 is an integer of 0-2. n2 is 0 or 1. If n2 is 0, ^{Y 2} is a single bond, ^{R 2} is preferably a group represented by the general formula (1-an1) or (1-an2).

In formula (a0-1), R ² and R ³ are each independently a functional group or a group represented by general formula (1-an1), (1-an2) or (1-an3) , R ² or R ³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3).

Examples of the functional group of R ² and R ³ include a group whose polarity is increased by the action of an acid, a substrate adhesion group, a polar group-containing aliphatic hydrocarbon group, a non-acid dissociable cyclic group, and the like. And at least one functional group selected from the group consisting of:

  Examples of the group whose polarity is increased by the action of an acid include an acetal type acid dissociable group, tertiary alkyl ester type acid dissociable group or tertiary alkyloxycarbonyl group described in detail in the structural unit (a1) described later. Is mentioned.

Examples of the acetal type acid dissociable group include a group represented by the general formula (a1-r-1) described later, and among the groups represented by the general formula (a1-r-1) described later, the general formula The case where Ra ′ ^{3 of the} group represented by (a1-r-1) is a cyclic hydrocarbon group is preferable.

  Examples of the tertiary alkyl ester type acid dissociable group include a group represented by the following general formula (a1-r-2), and examples of the group represented by the general formula (a1-r-2) include A group represented by general formula (a1-r2-1) or (a1-r2-2) described later is preferable, and a group represented by general formula (a1-r2-1) is more preferable. Furthermore, examples of the group represented by the general formula (a1-r2-1) include the following formulas (r-pr-m1) to (r-pr-m17) and formulas (r-pr-s1) to (r- pr-s18) is preferred.

  Examples of the tertiary alkyloxycarbonyl group include a group represented by general formula (a1-r-3) described later.

Examples of the substrate adhesive group include a lactone-containing cyclic group, a carbonate-containing cyclic group, and an —SO ₂ -containing cyclic group, which will be described in detail in the structural unit (a2) described later.

Examples of the lactone-containing cyclic group include cyclic groups containing a ring (lactone ring) containing —O—C (═O) — in the ring skeleton. Specifically, the lactone-containing cyclic group includes a general formula (a2- and groups represented by r-1) to (a2-r-7). In the present invention, groups represented by the following general formulas (a2-r-1) to (a2-r-2) are preferable.
Examples of groups represented by the general formulas (a2-r-1) to (a2-r-2) include (r-lc-1-1) to (r-lc-1-8) and (r- lc-2-1) to (r-lc-2-13).

-SO ₂ - containing cyclic group, -SO ₂ - within the ring skeleton thereof cyclic group can be mentioned which contain a ring containing, specifically, the general formula described below (a5-r-1) ~ ( and a group represented by a5-r-4). In the present invention, a group represented by general formula (a5-r-1) described later is preferable.
Examples of the group represented by the general formula (a5-r-1) include (r-ls-1-1) to (r-ls-1-33) described later.

  Examples of the carbonate-containing cyclic group include a cyclic group containing a ring (carbonate ring) containing —O—C (═O) —O— in the ring skeleton, and a general formula (ax3-r— described later). Examples include groups represented by 1) to (ax3-r-3).

  Examples of the polar group-containing aliphatic hydrocarbon group include groups described in detail in the structural unit (a3) described later, and the polar group preferably has a hydroxyl group, a cyano group, or a carboxy group.

  In the present invention, examples of the polar group-containing aliphatic hydrocarbon group include groups represented by the following general formulas (a3-r-1) to (a3-r-3), and the general formula (a3-r- The group represented by 1) is preferable.

  As the non-acid-dissociable cyclic group, the cyclic group may have a hetero atom (heterocyclic group) or may not have a hetero atom. As these non-acid dissociable cyclic groups, in addition to the aliphatic cyclic group in the structural unit (a4) described later, examples of the heterocyclic group also include the following heterocyclic groups.

  Since the compound of the present invention has the above functional group, it is useful in designing a polymer compound when used as a resist composition.

In formula (a0-1), at least one of R ^{2 and} R ³ is a group represented by general formula (1-an1), (1-an2) or (1-an3).

［式中、Ｙ¹は単結合または−ＳＯ_２−であり、Ｒ^５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、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。Ｘ^＋は有機カチオンまたは金属カチオンである。］

[Wherein Y ¹ represents a single bond or —SO ₂ —, and R ⁵ represents 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 have a group. X ⁺ is an organic cation or a metal cation. ]

In the formula, Y ¹ is a single bond or —SO ₂ —. R ⁵ is 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. R ⁵ is 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. In general formula (b-1), R ¹⁰¹ has a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent. And the same groups as the chain-like alkenyl groups. As the cyclic group which may have a substituent of R ⁵ , for example, in the alkyl group having 1 to 5 carbon atoms, in addition to the group described as R ¹⁰¹ in the general formula (b-1) described later, One of the hydrogen atoms may be a group substituted with a cyclic group which may have the substituent mentioned in R ¹⁰¹ .

X ⁺ is an organic cation or a metal cation, and examples thereof include an alkali metal cation and an organic cation. Examples of the alkali metal ion include sodium ion, lithium ion, potassium ion and the like, and sodium ion or lithium ion is preferable. Examples of the organic cation include nitrogen-containing cations such as ammonium ion and pyridinium ion; the same organic cation as M ^{m +} in the general formulas (b-1) to (b-3) described later.

Specific examples of the compound represented by formula (a0-1) are shown below. In the following formula, X ⁺ is an organic cation or a metal cation.

≪Polymer compound≫
The second aspect of the present invention is a polymer compound having a structural unit (a0) derived from a compound represented by the following general formula (a0-1).

［式中、Ｒ^１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り、Ｙ^２及びＹ^３はそれぞれ独立に、単結合または２価の連結基であり、Ｒ^２及びＲ^３はそれぞれ独立に、機能性基、または一般式（１−ａｎ１）、（１−ａｎ２）若しくは（１−ａｎ３）で表される基であって、Ｒ^２又はＲ^３の少なくとも一方は一般式（１−ａｎ１）、（１−ａｎ２）または（１−ａｎ３）で表される基である。ｎ１は、０〜２の整数である。ｎ２は０または１である。
Ｙ¹は単結合または−ＳＯ_２−であり、Ｒ^５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、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。Ｘ^＋は有機カチオンまたは金属カチオンである。］

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ² and Y ³ are each independently a single bond or a divalent linking group. R ² and R ³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ² or R 3 ^At least one of ³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n1 is an integer of 0-2. n2 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. X ⁺ is an organic cation or a metal cation. ]

In the formula ^(a0-1), description of R 1, ^{Y 2} and ^{Y 3, n1, Y 1,} R 5, X + is in the formula (a0-1) in the ^{«compound», R} 1, Y ² and Y ³ , n 1, Y ¹ , R ⁵ , X ⁺ are the same as described above.
The polymer compound of the present invention preferably has a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid. The structural unit (a1) that the polymer compound of the present invention preferably has is the same as the structural unit (a1) that (A1 ′) described later preferably has.
Moreover, the polymer compound of the present invention may have structural units (a2) to (a4) described later. The structural units (a2) to (a4) that the polymer compound of the invention preferably has are preferably the structural units (a2) to (a4) that the polymer compound (A1 ′) has. It is the same. The molecular weight and the degree of dispersion are the same as described in the component (A1 ′).

≪Resist composition 1≫
The resist composition according to the third aspect of the present invention (hereinafter sometimes referred to as “resist composition 1”) 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 a developing solution is changed by the action of an acid, wherein the base material component (A ′) is a compound represented by the general formula (a0-1) A polymer compound (A1 ′) having a derived structural unit (a0) is contained.

The resist composition of the third aspect of the present invention is a base material component (A ′) (hereinafter referred to as “(A ′) component”) that generates an acid upon exposure and changes its solubility in a developing solution by the action of the acid. It is also referred to as a resist composition.
Since the resist composition of this embodiment contains the component (A ′), it has a property that its solubility in a developer changes upon exposure. When a resist film is formed using the resist composition and selective exposure is performed on the resist film, an acid is generated from the component (A ′) at the exposed portion, and the acid is converted into the component (A ′). Change the solubility in the developer. As a result, the solubility of the exposed portion in the developer changes, while the solubility in the unexposed portion does not change in the developer. Therefore, when the resist film is developed, when the resist composition is positive, the exposed portion Is removed by dissolution to form a positive resist pattern. When the resist composition is negative, the unexposed portion is dissolved and 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 a resist composition that forms a negative resist pattern in which an unexposed portion is dissolved and removed. 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. Preferably, it is used for forming a positive resist pattern in an alkali development process. In this case, as the component (A ′), a component whose solubility in an alkali developer is increased by the action of an acid. Used.

<(A ') component>
The component (A ′) used in the resist composition of this embodiment is a base material component that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid. And a polymer compound (A1 ′) (hereinafter also referred to as “component (A1 ′)”).
Here, the “base component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed. “Organic compounds having a molecular weight of 500 or more” used as the base 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, a nonpolymer having a molecular weight of 500 or more and less than 4000 is referred to as a low molecular compound.
As the polymer, those having a molecular weight of 1000 or more are usually used. Hereinafter, a polymer having a molecular weight of 1000 or more is referred to as a polymer compound. In the case of a polymer compound, the “molecular weight” is a polystyrene-reduced mass average molecular weight measured by GPC (gel permeation chromatography). Hereinafter, the polymer compound may be simply referred to as “resin”.
As the component (A ′), a low molecular compound may be used in combination with the component (A1 ′).
Further, the component (A ′) containing the component (A1 ′) may be one whose solubility in the developer is increased by the action of an acid, and is one whose solubility in the developer is reduced by the action of an acid. May be.

[(A1 ′) component]
The component (A1 ′) is a polymer compound having the structural unit (a0) represented by the general formula (a0-1).
When the resist film formed using the resist composition of this embodiment is exposed, the structural unit (a0) is a structural unit in which at least a part of the bond in the structure is cleaved by the action of an acid and the polarity increases. It is. For this reason, the resist composition of this embodiment becomes a positive type in the alkali development process and a negative type in the solvent development process. Since the polarity of the component (A1 ′) changes before and after exposure, by using the component (A1 ′), good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
That is, when the alkali development process is applied, the component (A1 ′) is hardly soluble in an alkali developer before exposure. When an acid is generated from the structural unit (a0) by exposure, the component (A1 ′) is polar due to the action of the acid. Increase in solubility in an alkaline developer. 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 can be formed by alkali development.
On the other hand, when applying the solvent development process, the component (A1 ′) is highly soluble in an organic developer before exposure, and when an acid is generated from the structural unit (a0) by exposure, The polarity increases and the solubility in organic developers decreases. 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, by developing with an organic developer, a contrast can be provided between the exposed portion and the unexposed portion, and a negative resist pattern can be formed.

(Structural unit (a0))
The structural unit (a0) is a structural unit derived from a compound represented by the following general formula (a0-11).

［式中、Ｒ^１１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り、Ｙ^１２及びＹ^１３はそれぞれ独立に、単結合または２価の連結基であり、Ｒ^１２及びＲ^１３はそれぞれ独立に、機能性基、または一般式（１−ａｎ１）、（１−ａｎ２）若しくは（１−ａｎ３）で表される基であって、Ｒ^１２又はＲ^１３の少なくとも一方は一般式（１−ａｎ１）、（１−ａｎ２）または（１−ａｎ３）で表される基である。ｎ１１は、０〜２の整数である。ｎ１２は０または１である。
Ｙ¹は単結合または−ＳＯ_２−であり、Ｒ^５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、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。Ｍ^＋は有機カチオンである。］

[Wherein, R ¹¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ¹² and Y ¹³ are each independently a single bond or a divalent linking group. R ¹² and R ¹³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ¹² or R ^{13 At} least one of ¹³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n11 is an integer of 0-2. n12 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. M ⁺ is an organic cation. ]

In formula (a0-11), the description of R ^{11 is the same} as the description of R ¹ in formula (a0-1).
In the formula (a0-11), the description of Y ¹² and Y ^{13 is the same} as the description of Y ² and Y ³ in the formula (a0-1).
In formula (a0-11), the description for R ¹² or R ^{13 is the same} as the description for R ² or R ³ in formula (a0-1).
In formula (a0-11), n11 is an integer of 0-2. n12 is 0 or 1.
In formula (a0-11), Y ¹ is a single bond or —SO ₂ —, R ⁵ is a cyclic group which may have a substituent, or a chain alkyl which may have a substituent. Or a chain-like alkenyl group which may have a substituent. The explanation for R ⁵ is the same as described above.
In the formula (a0-11), M ⁺ is an organic cation. Examples of the organic cation of M ⁺ include the same organic cation of M ^{m +} in formulas (b-1) to (b-3) described later.

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 1 to 50 mol%, and preferably 5 to 45 mol%, based on the total of all structural units constituting the component (A1 ′). More preferably, 10-40 mol% is further more preferable.
By setting the proportion of the structural unit (a0) to be equal to or higher than the lower limit value, lithography properties such as MEEF, exposure margin and sensitivity are improved. Moreover, by making it into the upper limit value or less, it becomes easy to balance with other structural units, and a resist pattern having a good shape can be easily obtained.

  In the resist composition of the present invention, the polymer compound (A1 ′) preferably includes the following structural units (a1) to (a4).

(Structural unit (a1))
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.
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 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, “acid-dissociable group” means
(I) an acid-dissociable group 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, or
(Ii) a group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by further decarboxylation reaction after partial bond cleavage by the action of an acid ,
Both.
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, and when the developer is an organic developer, the solubility decreases.

The acid-dissociable group is not particularly limited, and those that have been proposed as acid-dissociable groups for base resins for chemically amplified resists can be used.
Among the polar groups, examples of the acid dissociable group that protects a carboxy group or a hydroxyl group include an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as “acetal acid dissociable for convenience”). Group ”).

［式中、Ｒａ’^１、Ｒａ’^２は水素原子またはアルキル基、Ｒａ’^３は炭化水素基、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 hydrogen atoms or alkyl groups, Ra ′ ³ is a hydrocarbon group, and Ra ′ ³ may be bonded to either Ra ′ ¹ or Ra ′ ² to form a ring. Good. ]

In formula (a1-r-1), Ra ′ ¹ and Ra ′ ² are exemplified as substituents that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester described above. Examples thereof include the same as the alkyl group, preferably a methyl group or an ethyl group, and most preferably a methyl group.

The hydrocarbon group for Ra ′ ³ is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms; a linear or branched alkyl group is preferable, specifically , Methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1-diethylpropyl group 2,2-dimethylpropyl group, 2,2, -dimethylbutyl group and the like can be mentioned.

When Ra ′ ³ is a cyclic hydrocarbon group, it may be aliphatic or aromatic, may be polycyclic, or may be monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples include 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 one having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

In the case of an aromatic hydrocarbon group, specific examples of the aromatic ring included include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; An aromatic heterocycle partially substituted with a heteroatom; and the like. 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.

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.

  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) (the following formula (a1-r-2) Among the acid dissociable groups represented by), those composed of an alkyl group may hereinafter be referred to as “tertiary alkyl ester type acid dissociable groups” for convenience).

［式中、Ｒａ’^４〜Ｒａ’^６は炭化水素基であり、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 hydrocarbon groups, 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. In the case where 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. ]

In formula (a1-r2-1), the alkyl group of the alkyl group having 1 to ¹⁰ carbon atoms of Ra ′ ¹⁰ is a linear or branched alkyl group of Ra ′ ³ in formula (a1-r-1) The groups mentioned as are preferred. Wherein (a1-r2-1), Ra 'aliphatic cyclic ^{group 11} is configured, Ra in formula (a1-r-1)' group listed as a cyclic alkyl group of ³ is 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 is a linear, branched or cyclic alkyl group exemplified as the hydrocarbon group for Ra ′ ³ in formula (a1-r-1). Is preferred. Among these, a group exemplified as the cyclic alkyl group for Ra ′ ³ is more preferable.

  Specific examples of the formula (a1-r2-1) are given below. In the following formula, “*” indicates a bond.

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

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

［式中、Ｒａ’^７〜Ｒａ’^９はアルキル基を示す。］

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

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

  The structural unit (a1) is 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, and an acid whose polarity is increased by the action of an acid. A structural unit containing a decomposable group; a structural unit in which at least a part of hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected by a substituent containing the acid-decomposable group; vinylbenzoic acid or Examples include a structural unit in which at least a part of hydrogen atoms in —C (═O) —OH of a structural unit derived from a vinylbenzoic acid derivative 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.
As the structural unit (a1), structural units represented by general formula (a1-1) shown below are preferred.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基である。Ｖａ^１はエーテル結合、ウレタン結合、又はアミド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）〜（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）または（ａ１−ｒ−３）で表される酸解離性基である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group which may have an ether bond, a urethane bond, or an amide bond, _na1 is 0 to 2,
Ra ¹ is an acid dissociable group represented by the above formulas (a1-r-1) to (a1-r-2).
Wa ¹ is n _a2 +1 valent hydrocarbon group, n _a2 is 1 to 3,
Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3). ]

In the general formula (a1-1), the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, Examples include 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.
The hydrocarbon group for Va ¹ 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 ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specific 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.
Examples of Va ¹ include those in which the divalent hydrocarbon group is bonded via an ether bond, a urethane bond, or an amide bond.

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 polycyclic or monocyclic. 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 is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and 6 to 6 carbon atoms. 15 is particularly preferable, and 6 to 10 is most preferable. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; a part of carbon atoms constituting the aromatic hydrocarbon ring is hetero Aromatic heterocycles substituted with atoms; and the like. 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 two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) ) In which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) Group in which one hydrogen atom is further removed from the aryl group in the group); and the like. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

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. It includes a group formed by combining an aliphatic hydrocarbon group in the structure containing a ring, and specific examples thereof include the same groups as Va ¹ of the aforementioned formula (a1-1).
The n _a2 +1 valence is preferably 2 to 4, and more preferably 2 or 3.

  As the formula (a1-2), a structural unit represented by general formula (a1-2-01) shown below is particularly desirable.

In formula (a1-2-01), Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3). n _a2 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. c is an integer of 0 to 3, preferably 0 or 1, and more preferably 1. R is the same as described above.
Specific examples of the above formulas (a1-1) and (a1-2) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  The proportion of the structural unit (a1) in the component (A ′) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, with respect to all structural units constituting the component (A ′). More preferred is mol%. By setting the lower limit value or more, lithography properties such as sensitivity, resolution, and roughness are improved. Moreover, the balance with another structural unit can be taken by making it below an upper limit.

(Structural unit (a2))
The structural unit (a2) is a structural unit containing a lactone-containing cyclic group, a carbonate-containing cyclic group, or an —SO ₂ -containing cyclic group, and does not correspond to the structural unit (a0).
The lactone-containing cyclic group or carbonate-containing cyclic group of the structural unit (a2) is effective for enhancing the adhesion of the resist film to the substrate when the component (A1 ′) is used for forming the resist film. It is.
In addition, when the structural unit (a1) includes a lactone-containing cyclic group or a carbonate-containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a2). It corresponds to the structural unit (a1) and does not correspond to the structural unit (a2).
The —SO ₂ — containing cyclic group of the structural unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when the component (A1 ′) is used for forming the resist film.
In addition, when the structural unit (a1) includes a —SO ₂ — containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a2). It corresponds to a1) and does not correspond to the structural unit (a2).

  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り、Ｙａ^２１は単結合または２価の連結基であり、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。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, Ya ²¹ is a single bond or a divalent linking group, and La ²¹ is —O -, -COO-, -CON (R ')-, -OCO-, -CONHCO- or -CONHCS-, wherein 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. ]

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)
The hydrocarbon group as the divalent linking group 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 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. Specifically, the above-described formula (a1- The group illustrated by Va ¹ in 1) is mentioned.

  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.

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 (excluding two hydrogen atoms from the aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched chain fatty acid. Group intervening in the middle of the group 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.
Specific examples of the cyclic aliphatic hydrocarbon group include the groups exemplified for Va ¹ in the above formula (a1-1).
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.

Specific examples of the aromatic hydrocarbon group as the divalent hydrocarbon group include groups exemplified by Va ¹ in the above formula (a1-1).
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.

(Divalent linking group containing a hetero atom)
The hetero atom in the divalent linking group containing a hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

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 - A group represented by C (═O) —O—, — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (═O) —Y ²² — In the formula, Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m ′ is an integer of 0 to 3. ] Etc. are mentioned.
When the divalent linking group containing a hetero atom is —C (═O) —NH—, —NH—, —NH—C (═NH) —, H is a substituent such as an alkyl group or acyl. May be substituted. 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 -, - [Y 21 -C (= O) -O] m '-Y 22 - or ^{-Y 21 -O-C (= O} ) -Y 22 - ^{in, Y 21} and ^{Y 22} are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include those similar to the “divalent hydrocarbon group optionally having substituent (s)” mentioned in the description of the divalent linking group.
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 —. The group is particularly preferred. Among these, a group represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} — is preferable. In the formula, a ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 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.

Ya ²¹ in the present invention is a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. It is preferable.

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or an —SO ₂ -containing cyclic group.

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 as the cyclic hydrocarbon group for R ¹ is not particularly limited, and any one can be used. Specific examples include groups represented by the following general formulas (a2-r-1) to (a2-r-7). Hereinafter, “*” represents a bond.

［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”は水素原子またはアルキル基であり；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 or an alkyl group; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n ′ is 0 to 2 And m ′ is 0 or 1. ]

In general formulas (a2-r-1) to (a2-r-7), A ″ represents an oxygen atom (—O—) or a sulfur atom (—S—), and may have 1 to 5 carbon atoms. The alkylene group having 1 to 5 carbon atoms in A ″ is preferably a linear or branched alkylene group, a methylene group, an ethylene group, an n-propylene group, An isopropylene 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. A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group. Ra ′ ²¹ independently represents an alkyl group or an alkoxy group. A group, a halogen atom, a halogenated alkyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group.
The alkyl group in ra ^'21, preferably an alkyl group having 1 to 5 carbon atoms.
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 a hydrogen atom or an alkyl group.

  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 monocyclic or polycyclic.
The —SO ₂ — containing cyclic group as the cyclic hydrocarbon group in R ¹ is particularly a cyclic group containing —O—SO ₂ — in its ring skeleton, that is, —O— in —O—SO ₂ —. -S- is preferably a cyclic group containing a sultone ring that forms part of the ring skeleton. More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by the following general formulas (a5-r-1) to (a5-r-4).

［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”は水素原子またはアルキル基であり；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 or an alkyl group; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n ′ is 0 to 2 Is an integer. ]

In the general formulas (a5-r-1) to (a5-r-4), A ″ is the same as A ″ in the general formulas (a2-r-1) to (a2-r-7). 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 The same as Ra ′ ²¹ in −r-7).

  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.

As the —SO ₂ — containing cyclic group, among the above, a group represented by the general formula (a5-r-1) is preferable, and the chemical formulas (r-sl-1-1) and (r-sl— It is more preferable to use at least one selected from the group consisting of groups represented by any one of 1-18), (r-sl-3-1) and (r-sl-4-1), The group represented by (r-sl-1-1) is most preferable.

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.
The carbonate ring-containing cyclic group as the cyclic hydrocarbon group for R ¹ is not particularly limited, and any one can be used. 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”は水素原子またはアルキル基であり；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 or an alkyl group; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and q ′ is 0 or 1. is there. ]

In the general formulas (ax3-r-1) to (ax3-r-3), A ″ is the same as A ″ in the general formula (a2-r-1).
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.

Among these, a lactone-containing cyclic group or a —SO ₂ — containing cyclic group is preferable, and is represented by the general formula (a2-r-1), (a2-r-2), or (a5-r-1). The groups represented by the formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-13), (r- Any of the groups (sl-1-1) and (r-sl-1-18) is more preferable.

The structural unit (a2) contained in the component (A1 ′) may be one type or two or more types.
When the component (A1 ′) has the structural unit (a2), the proportion of the structural unit (a2) is 1 to 80 mol% with respect to the total of all the structural units constituting the component (A1 ′). It is preferably 5 to 70 mol%, more preferably 10 to 65 mol%, and particularly preferably 10 to 60 mol%. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units, such as various kinds of DOF, CDU, etc. The lithography characteristics and pattern shape of the film 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 the structural units (a0), (a1), and (a2) described above).
When the component (A1 ′) has the structural unit (a3), it is considered that the hydrophilicity of the component (A ′) is increased and the resolution is improved.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which part of hydrogen atoms of an alkyl group is substituted with a fluorine atom, and 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.
Examples of the polar group-containing aliphatic hydrocarbon group contained in the structural unit (a3) include groups represented by the following general formulas (a3-r-1) to (a3-r-3). In the following formula, “*” indicates a bond.

［式中、Ｗａ’^３１、Ｗａ’^３２、Ｗａ’^３３はそれぞれ独立に（ｎ’＋１）価の脂肪族炭化水素基であり、ｎ’は１〜３の整数であり、Ｒａ’^３１、Ｒａ’^３２はフッ素原子またはフッ素化アルキル基である。］

[Wherein, Wa ′ ³¹ , Wa ′ ³² and Wa ′ ³³ are each independently an (n ′ + 1) -valent aliphatic hydrocarbon group, n ′ is an integer of 1 to 3, Ra ′ ³¹ , Ra ^'32 is a fluorine atom or a fluorinated alkyl group. ]

In the general formulas (a3-r-1) to (a3-r-3), Wa ′ ³¹ , Wa ′ ³² , and Wa ′ ³³ are each independently an (n ′ + 1) -valent aliphatic hydrocarbon group. The description regarding the aliphatic hydrocarbon group is the same as the description regarding the aliphatic hydrocarbon group described in the divalent linking group for Y ² and Y ³ in the formula (a0-1).

  In the general formulas (a3-r-1) to (a3-r-3), n ′ is an integer of 1 to 3.

In the general formulas (a3-r-1) to (a3-r-3), Ra ′ ³¹ and Ra ′ ³² are a fluorine atom or a fluorinated alkyl group. Examples of the fluorinated alkyl group include fluorinated alkyl groups having 1 to 5 carbon atoms.

  Specific examples of the groups represented by the general formulas (a3-r-1) to (a3-r-3) are shown below.

As the structural unit (a3) contained in the component (A1 ′), 1 type of structural unit may be used, or 2 or more types may be used.
In the component (A1 ′), the proportion of the structural unit (a3) is preferably 1 to 50 mol%, and preferably 5 to 40 mol% with respect to the total of all the structural units constituting the resin component (A1 ′). Is more preferable, and 5 to 25 mol% is more preferable.
By setting the proportion of the structural unit (a3) to the lower limit value or more, the effect of including the structural unit (a3) can be sufficiently obtained, and by setting the proportion of the structural unit (a3) to the upper limit value or less, balance with other structural units can be obtained. It becomes easy.

(Structural unit (a4))
The structural unit (a4) is a structural unit containing an acid non-dissociable cyclic group. When the component (A1 ′) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Further, the hydrophobicity of the component (A1 ′) is increased. The improvement in hydrophobicity is thought to contribute to the improvement of resolution, resist pattern shape, etc., particularly in the case of organic solvent development.
The “acid non-dissociable cyclic group” in the structural unit (a4) is a ring that remains in the structural unit without being dissociated even when the acid acts when an acid is generated from the component (B) by exposure. Formula group.
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. Examples of the cyclic group include those similar to those exemplified for the structural unit (a1), for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser), etc. A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a 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 those having the structures of the following general formulas (a4-1) to (a4-7).

［式中、Ｒ^αは、水素原子、メチル基またはトリフルオロメチル基を示す。］

[Wherein, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group. ]

As the structural unit (a4) contained in the component (A1 ′), 1 type of structural unit may be used, or 2 or more types may be used.
When the structural unit (a4) is contained in the component (A1 ′), the proportion of the structural unit (a4) is 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1 ′). Preferably, it is 10 to 20 mol%.

  The component (A1 ′) is preferably a copolymer having the structural unit (a0). The copolymer having the structural unit (a0) is preferably a copolymer further having any one of (a1), (a2), (a3) and (a4), and the structural units (a1) and ( A copolymer having a2), structural units (a1), (a2), or structural units (a1), (a2), (a3) is more preferable.

In the present invention, the weight average molecular weight (Mw) of the component (A1 ′) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, 2000-20000 is 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 (A1 ′) is preferably 1.0 to 5.0, and more preferably 1.0 to 3.0.

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 substrate component (A ′) is preferably 25% by mass or more, more preferably 50% by mass, and further 75% by mass with respect to the total mass of the substrate component (A ′). Preferably, it may be 100% by mass. When the proportion is 25% by mass or more, lithography properties such as MEEF and roughness reduction are further improved.

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

<Acid generator component; (B) component>
The resist composition of the present invention may contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as component (B)). The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used.
Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, 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. Moreover, you may use together the below-mentioned acid generator (B1 ') as (B) component.

  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^１０６〜Ｒ^１０７のいずれか２つは、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’^ｍ＋はｍ価の有機カチオンである（前記式（ｂ１−１）の化合物におけるカチオンを除く）。］

[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. Any two of R ^{106 to} R ¹⁰⁷ 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 ′ ^{m +} is an m-valent organic cation (excluding the cation in the compound of the formula (b1-1)). ]

{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.
The aromatic hydrocarbon group for R ¹⁰¹ is the aromatic hydrocarbon ring mentioned for the divalent aromatic hydrocarbon group for Va ¹ in the formula (a1-1), or an aromatic compound containing two or more aromatic rings. Examples include an aryl group in which one hydrogen atom is removed, and a phenyl group and a naphthyl group are preferable.
The cyclic aliphatic hydrocarbon group for R ¹⁰¹ is a group obtained by removing one hydrogen atom from the monocycloalkane or polycycloalkane mentioned as the divalent aliphatic hydrocarbon group for Va ¹ in the formula (a1-1). And an adamantyl group and a norbornyl group are preferable.
In addition, the cyclic hydrocarbon group in R ¹⁰¹ may contain a hetero atom such as a heterocycle, and is specifically represented by the general formulas (a2-r-1) to (a2-r-7). include-containing cyclic group, a heterocyclic group mentioned for other less - lactone-containing cyclic group, -SO ₂ respectively represented by the general formula (a5-r-1) ~ (a5-r-4) to be It is done.

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, and a nitro group.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, 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 chain 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.

(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 a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the chain alkenyl group is particularly preferably a propenyl 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, a nitro group, an amino group, and the cyclic group in R ¹⁰¹ described above. Can be mentioned.

Among these, 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, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a 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 preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group of Ra ′ ^{3 in} the formula (a1-r-1). 1,5-adamantylene group or 2,6-adamantylene group is more preferable.

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.

As a specific example of the anion part of the component (b-1), for example,
When Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion and perfluorobutane sulfonate anion can be mentioned; when Y ¹⁰¹ is a divalent linking group containing an oxygen atom, the following formula (an An anion represented by any one of (-1) to (an-3).

［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”^１０１は、フッ素化アルキレン基であり；Ｌ”^１０１は、−Ｃ（＝Ｏ）−又は−ＳＯ_２−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、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. ^{There; V "101} is an fluorinated alkylene ^{group; L" 101} is, -C (= O) - or -SO ₂ - a and; v "0 to 3 are each independently Is an integer, q "are each independently an integer of 1 to 20, n" is 0 or 1. ]

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

R have a substituent in "which may chain substituted at ¹⁰¹ alkyl group, wherein preferably a group exemplified as chain alkyl group in R ¹⁰¹ .R" ¹⁰³ The good chain alkenyl group is preferably the group exemplified as the chain alkenyl group in R ¹⁰¹ . V ″ ¹⁰¹ is preferably a fluorinated alkylene group having 1 to 3 carbon atoms, and particularly preferably —CF ₂ —, —CF ₂ CF ₂ —, —CHFCF ₂ —, —CF (CF ₃ ) CF ₂ —. , —CH (CF ₃ ) CF ₂ —.

-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.

-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 —.

{Cation part}
In the formulas (b-1), (b-2) and (b-3), M ′ ^{m +} is an m-valent organic cation other than the cation in the compound of the formula (b1-1), and in particular, a sulfonium cation Or it is preferable that it is an iodonium cation, and the cation respectively represented by the following general formula (ca-1)-(ca-4) is especially preferable.

［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 an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and an arylthio group. And groups represented by the following formulas (ca-r-1) to (ca-r-7).
The aryl group in the arylthio group as a substituent is the same as that described for R ¹⁰¹ , and specifically includes a phenylthio group or a biphenylthio group.

［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, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent are the above-mentioned In addition to the same groups as those described above for R ^{101 in} formula (b-1), a cyclic group which may have a substituent or a chain alkyl group which may have a substituent may have the above formula ( Examples thereof include the same acid dissociable groups represented by a1-r-2).

^{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, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when formed into an alkyl group, they are bonded to each other to form 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 general formula (a2-1). The group represented by the general formula (a5-r-1) 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 above formula (b-1).
Examples of the alkylene group and alkenylene group for Y ²⁰¹ include the same aliphatic hydrocarbon groups as the divalent hydrocarbon group for Va ¹ in the general formula (a1-1).

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 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-1-63), 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-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).

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.
When the resist composition of this invention contains (B) component, 0.5-60 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component, 1-50 mass parts Is more preferable, and 1-40 mass parts is further more preferable. By forming the content of the component (B) within the above 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.

<Basic compound component; (D) component>
The resist composition of the present invention is also referred to as an acid diffusion controller component (hereinafter referred to as “(D) component”) in addition to the component (A ′) or in addition to the component (A ′) and the component (B). ) May be contained.
The component (D) acts as a quencher (acid diffusion controller) that traps acid generated by exposure from the component (B) and the like.
The component (D) in the present invention may be a photodegradable base (D1) (hereinafter referred to as “(D1) component”) that is decomposed by exposure and loses acid diffusion controllability. A non-corresponding nitrogen-containing organic compound (D2) (hereinafter referred to as “component (D2)”) may be used.

[(D1) component]
By forming the resist composition containing the component (D1), the contrast between the exposed portion and the non-exposed portion can be improved when forming a resist pattern.
The component (D1) is not particularly limited as long as it is decomposed by exposure and loses acid diffusion controllability, and is a compound represented by the following general formula (d1-1) (hereinafter referred to as “(d1-1) component”). ), A compound represented by the following general formula (d1-2) (hereinafter referred to as “(d1-2) component”) and a compound represented by the following general formula (d1-3) (hereinafter referred to as “(d1- One or more compounds selected from the group consisting of “3) component”) are preferred.
The components (d1-1) to (d1-3) are decomposed in the exposed portion and lose acid diffusion controllability (basicity), and thus do not act as a quencher, and act as a quencher in an unexposed portion.

［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、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。ただし、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、または２価の連結基である。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 ^{m +} is each independently an m-valent organic cation. ]

{(D1-1) component}
During Anion formula (d1-1), Rd ¹ is have an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, Or a similar chain alkenyl group to the same as R ¹⁰¹ .
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 hydrocarbon group is preferred. The substituent that these groups may have is preferably a hydroxyl group, a fluorine atom or a fluorinated alkyl group.
The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group.
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.
As the chain hydrocarbon group, a chain alkyl group is preferable. The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a nonyl group. A linear alkyl group such as a group or decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group And branched chain alkyl groups such as 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, and the like.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms. The fluorinated alkyl group, more preferably ˜4, 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.

-Cation part In formula (d1-1), Mm ⁺ is an m-valent organic cation.
The organic cation of M ^{m +} is not particularly limited, and examples thereof include those similar to the cations represented by the general formulas (ca-1) to (ca-4), respectively, and the formula (ca-1- Cations represented by 1) to (ca-1-63) are preferable.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

{(D1-2) component}
· During anion formula (d1-2), Rd ² is has an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, A chain alkenyl group which may be the same as R ¹⁰¹ .
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 of (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.

-Cation part In formula (d1-2), Mm ⁺ is an m-valent organic cation, and is the same as Mm ⁺ 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}
During Anion formula (d1-3), Rd ³ is have an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, A chain alkenyl group that may be the same as R ^101, and is preferably a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. 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 .
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 in Rd ⁴ include those similar to R ¹⁰¹ described above, 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 the same groups as those described above for R ^101, and one or more hydrogen atoms are removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group 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. These may be the same as those exemplified in the description of the divalent linking group of Ya ²¹ in the formula (a2-1).
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.

-Cation part In formula (d1-3), Mm ⁺ is an m-valent organic cation, and is the same as Mm ⁺ 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.
The content of the component (D1) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass with respect to 100 parts by mass of the component (A ′). More preferably, it is 8 parts by mass.
When the content of the component (D1) is not less than the preferable lower limit value, particularly good lithography characteristics and a resist pattern shape can be obtained. On the other hand, when it is not more than the upper limit value, the sensitivity can be maintained well and the throughput is also excellent.

  The manufacturing method of said (d1-1) component and (d1-2) component is not specifically limited, It can manufacture by a well-known method.

  The content of the component (D1) is preferably 0.5 to 10.0 parts by mass and more preferably 0.5 to 8.0 parts by mass with respect to 100 parts by mass of the component (A ′). Preferably, it is 1.0-8.0 mass parts. When it is at least the lower limit of the above range, particularly good lithography properties and resist pattern shape can be obtained. When it is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

((D2) component)
(D) component may contain the nitrogen-containing organic compound component (henceforth (D2) component) which does not correspond to the said (D1) component.
The component (D2) is not particularly limited as long as it functions as an acid diffusion control agent and does not correspond to the component (D1), and any known component may be used. Of these, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , 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.
Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxy. And carbonylpyrrolidine.

(D2) A component may be used independently and may be used in combination of 2 or more type.
(D2) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A ') component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

(D) A component may be used individually by 1 type and may be used in combination of 2 or more type.
When the resist composition of this invention contains (D) component, it is preferable that (D) component is 0.1-15 mass parts with respect to 100 mass parts of (A ') component, and 0.3 More preferably, it is -12 mass parts, and it is further more preferable that it is 0.5-12 mass parts. When it is at least the lower limit of the above range, lithography properties such as LWR are further improved when a resist composition is used. Further, a better resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

<Optional component>
[(E) component]
The resist composition of the present invention comprises, as optional components, an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, and the like. At least one compound (E) selected from the group (hereinafter referred to as component (E)) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids 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.
(E) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A ') component.

[(F) component]
The resist composition of the present invention 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 JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, and JP 2011-128226 A. The described fluorine-containing polymer compound 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). As the polymer, a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a structural unit (f1) represented by the following formula (f1-1); A copolymer with the structural unit (a1); a structural unit (f1) represented by the following formula (f1-1); a structural unit derived from acrylic acid or methacrylic acid; and the structural unit (a1) It is preferable that it is a copolymer. Here, as the structural unit (a1) copolymerized with the structural unit (f1) represented by the following formula (f1-1), 1-ethyl-1-cyclooctyl (meth) acrylate or the formula (a1) -2-01) is preferred.

［式中、Ｒは前記同様であり、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 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 methyl _{group, -CH 2 -CF 3, -CH 2} -CF 2 -CF 3, -CH (CF 3) 2 _{, -CH} 2 _-CH 2 _-CF 3, and most preferably _{-CH 2 -CH 2 -CF 2 -CF 2} -CF 2 -CF 3.

(F) As for the weight average 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.
The component (F) is 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 invention further contains, if desired, miscible additives such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, A dye or the like can be appropriately added and contained.

[(S) component]
The resist composition of the present invention can be produced by dissolving the 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 (2-heptanone), methyl isopentyl ketone; ethylene glycol, diethylene glycol, propylene glycol, di- Polyhydric alcohols such as propylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, the polyhydric alcohols or compounds having the ester bond Monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) among these; cyclic ethers such as dioxane, , Methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc .; anisole, ethyl benzyl ether, cresyl methyl Ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene And aromatic organic solvents such as dimethyl sulfoxide (DMSO).
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, and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL 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.
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.

The resist composition (resist composition 1) of the third aspect of the present invention is excellent in various lithography characteristics such as LWR and EL margin and resist pattern shape.
Although the reason why the above effect is obtained is not clear, the resist composition 1 contains the structural unit (a0) that generates an acid upon exposure in the component (A ′) that is the base material (A ′). It is uniformly distributed in the resist film together with the components, and the acid is generated uniformly from the structural unit (a0) in the exposed portion, whereby the acid-decomposable group in the (A ′) component of the exposed portion is cleaved uniformly, It is considered that the above effect can be obtained.

≪Resist composition 2≫
The resist composition according to the fourth aspect of the present invention (hereinafter sometimes referred to as “resist composition 2”) has a base component (A) (hereinafter referred to as “resin composition 2”) whose solubility in a developer is changed by the action of an acid. (A) component ”) and an acid generator component (B ′) that generates an acid upon exposure, wherein the acid generator component (B ′) is represented by the general formula (a0−). The acid generator (B1 ') containing the compound represented by 11) is contained.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
In the resist composition 2 of the present invention, the component (A) is a base material component (component (A)) whose solubility in a developer is changed by the action of an acid.

[(A) component]
As the component (A), a resin component (base resin) that is usually used as a base component for a chemically amplified resist can be used singly or in combination of two or more.
In the present invention, the component (A) preferably has a structural unit derived from an acrylate ester in which an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom.
In the resist composition 2 of the present invention, in particular, the component (A) is a structural unit derived from an acrylate ester in which an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom. Thus, it is preferable to have a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid.

The proportion of the structural unit (a1) in the component (A) is preferably from 15 to 80 mol%, more preferably from 20 to 75 mol%, more preferably from 25 to 70 mol%, based on all structural units constituting the component (A). Is more preferable. By setting the lower limit value or more, lithography properties such as sensitivity, resolution, and LWR are also improved. Moreover, the balance with another structural unit can be taken by making it below an upper limit.

In addition to the structural unit (a1), the component (A) further includes a —SO ₂ — containing cyclic group, and an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom. A structural unit derived from a good acrylate ester, and a structural unit derived from an acrylate ester containing a lactone-containing cyclic group, and an atom or substituent other than a hydrogen atom may be bonded to the α-position carbon atom It is preferable to have at least one structural unit (a2) selected from the group consisting of

In addition to the structural unit (a1) or in addition to the structural units (a1) and (a2), the component (A) further includes a polar group-containing aliphatic hydrocarbon group, and has a carbon atom at the α-position. It is preferable to have a structural unit (a3) derived from an acrylate ester to which an atom other than a hydrogen atom or a substituent may be bonded.
Moreover, (A) component may have the structural unit (a4) which does not correspond to the said structural unit (a1)-(a3).
The structural units (a1) to (a4) are the same as the structural units (a1) to (a4) in the resist composition 1 of the third aspect. The component (A1) is the same as the component (A1 ′) except that it does not contain the structural unit (a0) as an essential component.

<(B ′) component>
[(B1 ′) component]
The resist composition 2 of the present invention is an acid generator component (B ′) that generates an acid upon exposure (hereinafter also referred to as “(B ′) component”), and the acid generator component (B ′). Contain the acid generator (B1 ') containing the compound represented by general formula (a0-11).
The description of the compound represented by the general formula (a0-11) is the same as described above.

As the component (B1 ′), one type may be used alone, or two or more types may be used in combination.
In the resist composition of the present invention, the content ratio of the component (B1 ′) in the component (B ′) is preferably 40% by mass or more, more preferably 60% by mass or more, and even 100% by mass. Good.
The content ratio of the component (B1 ′) in the component (B ′) when combined with the following component (B2 ′) is preferably 50 to 95% by mass, and more preferably 60 to 85% by mass. As the component (B2 ′), it is preferable to use an onium salt acid generator of the compounds represented by the above formulas (b-1) to (b-3).

[(B2 ′) component]
In the resist composition 2 of the present invention, as the component (B ′), in addition to the component (B1 ′), an acid generator component (hereinafter referred to as “(B2 ′)” which does not correspond to the component (B1 ′) as necessary. Component ")).
Although it does not specifically limit as (B2 ') component, For example, in the resist composition 1 of the said 3rd aspect, (B1') among the acid generators mentioned as (B) component of an arbitrary component. The thing which does not correspond to an ingredient is mentioned.
As the component (B2 ′), one type of acid generator may be used alone, or two or more types may be used in combination.

  1-70 mass parts is preferable with respect to 100 mass parts of (A) component, as for the total content of (B ') component in the resist composition 2 of this invention, 3-60 mass parts is more preferable, and 5-50 Part by mass is most preferred. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

  The resist composition 2 of the present invention may contain a component (D), a component (E), and a component (F) as optional components, similar to the resist composition 1 of the third aspect. It may be produced by dissolving in component S). The component (D), the component (E), the component (F), and the component (S) are the same as those in the resist composition 1 of the third aspect.

The resist composition (resist composition 2) of the fourth aspect of the present invention is excellent in lithography properties such as pattern shape, LWR, EL margin, and pattern shape.
The reason why the above effect is obtained is not clear, but the resist composition 2 has a resist film uniformity due to the solubility of the acid generator in the component (S) and the good interaction with the component (A). Since it is possible to improve and control the diffusion length of acid generated by exposure, it is considered that good lithography characteristics can be obtained.

≪Resist pattern formation method≫
A resist pattern forming method according to a fifth aspect of the present invention comprises a step of forming a resist film on a support using the resist composition of the present invention, a step of exposing the resist film, and the resist film And developing to form a resist pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
First, the resist composition of the present invention is coated on a support with a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 A resist film is formed by applying for 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.

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. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents can be used.
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.
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 to continue (dynamic dispensing method) etc. are mentioned.

  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 more concretely, this invention is not limited to a following example.

[Compound synthesis example]
Reaction 1
Under a nitrogen atmosphere, 10 g of compound (i) and 150 g of dichloromethane were added to a three-necked flask at 10 ° C. or lower. 9.81g of triethylamine was dripped there. After stirring for 5 minutes, 9.36 g of methacrylic acid chloride was added dropwise. Then, after stirring for 5 minutes, it stirred at room temperature for 10 hours, Then, 150 g of 1% HCl was washed with water and dried. The mixture was purified by silica gel column chromatography to obtain 10.5 g of compound (ii).

Reaction 2
Under a nitrogen atmosphere, 10 g of compound (ii) and 100 g of dichloromethane were added to a three-necked flask. Triethylamine 6.01g was dripped there. After stirring for 5 minutes, 7.06 g of thionyl chloride was added dropwise. Thereafter, after stirring for 2 hours, a solution of 6.78 g of ethylcyclopentanol in 67.8 g of dichloromethane was added dropwise. After stirring at room temperature for 14 hours, 100 g of 1% HCl, washed with water and dried. The mixture was purified by silica gel column chromatography to obtain 8.85 g of compound (iii).

Reaction 3 (Na salt is used in the reaction)
8 g of compound (iii) and 4.94 g of compound (iv) were dissolved in 125 g of dichloromethane, 0.66 g of NN-dimethylaminopyridine was added, and 4.40 g of isopropylcarbodiimide was added dropwise. The mixture was reacted at room temperature for 24 hours, and the powder obtained by adding hexane to the reaction solution was dried to obtain 12.5 g of a mixture containing the compound (v).

To the eggplant flask, 53 g of dichloromethane and 53 g of pure water were added to 4.44 g of triphenylsulfonium bromide. Then, 8.37 g of compound (v) was added and stirred for 2 hours. Thereafter, the resultant was washed with a dichloromethane layer, washed repeatedly with pure water (20.0 g) until neutrality, and the organic layer was concentrated under reduced pressure to obtain 5.31 g of Compound (4). The obtained compound (4) was subjected to NMR measurement, and the structure was identified from the following results.
¹ H-NMR (400 MHz, dmso-d6): δ (ppm) = 7.74-7.90 (15H, m), 6.06 (1H, d), 5.57 (1H, d), 5. 43 (1H, t), 4.66 (2H, s), 3.16 (2H, d), 2.01 (1H, m), 1.87-1.82 (6H, m), 1.75 (1H, m), 1.66 (2H, q), 1.63 (3H, m), 0.93 (3H, t)

  The following compounds (5) to (96) were obtained by the same method as above. The NMR measurement results of the compounds (5) to (96) are shown in Tables 1 to 31.

[Synthesis example of polymer compound]
In a three-necked flask connected with a thermometer and a reflux tube, 20 g (117.5 mmol) of the following monomer (1), 27.5 g (117.5 mmol) of the following monomer (2), 13.9 g (58.8 mmol) The following monomer (3), 6.15 g (8.73 mmol) of the following monomer (4) was dissolved in 80 g of cyclohexanone. To this solution, 7.77 g of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved.
The resultant was dropwise added to 30 g of cyclohexanone heated to 80 ° C. in a nitrogen atmosphere over 4 hours. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature.
The obtained reaction polymerization solution is dropped into a large amount of methanol to perform polymer precipitation, and the precipitated white powder is filtered, washed with methanol and heptane, dried, and the target polymer compound 40.5 g of 1 was obtained.
The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement for this polymer compound was 7800, and the molecular weight dispersity (Mw / Mn) was 1.82.
Moreover, the composition ratio (ratio (molar ratio) of each structural unit in the structural formula) of the copolymer determined by ¹³ C-NMR is 1 / m / n / o = 40.1 / 36.9 / 19. 3 / 3.7.

  The high molecular compounds 2-12 were synthesize | combined by the method similar to the high molecular compound 1 using the following monomers (1)-(10) which derive | lead the structural unit which comprises each high molecular compound. About the obtained high molecular compound, the copolymer composition ratio (ratio (molar ratio) of each structural unit in structural formula) calculated | required by the carbon 13 nuclear magnetic resonance spectrum (600MHz-13C-NMR, internal standard: tetramethylsilane). ) And mass average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) in terms of standard polystyrene determined by GPC measurement are shown in Tables 32-33, respectively.

  Using the obtained polymer compound, resist compositions (Examples 1 to 21 and Comparative Examples 1 to 7) were prepared by blending the components at the blending ratios shown in Tables 34 to 37 below.

In Tables 34 to 37, each symbol has the following meaning, and the numerical value in [] is the blending amount (part by mass).
-(A) -1-(A) -12: The said high molecular compounds 1-12, respectively.
-(B) -4, (B) 5, (B) -6: The said compound (4), (5), (6), respectively.
-(B) -13- (B) -14: The following compounds (B) -13- (B) -14, respectively.
-(D1) -1: The following compound (D1) -1.
-(D2) -1: Tri-n-pentylamine.
-(E) -1: salicylic acid.
-(F) -1: The following high molecular compound (F) -1. (Molar ratio: 1 / m = 78/22), Mw is 18000, and Mw / Mn is 1.50.
-(S) -1: PGMEA / PGME = 3/2 mixed solvent.

<Resist pattern formation 1; Examples 1 to 3, Comparative Example 1>
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.
Each of the resist compositions shown in Table 34 (Examples 1 to 3 and Comparative Example 1) was applied onto the antireflection film using a spinner, and prebaked (PAB) treatment at 100 ° C. for 60 seconds on a hot plate. By performing and drying, 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 (in / out = 0.78 / 0.97) with Polano, An immersion medium: water] was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (6% halftone).
Thereafter, PEB treatment was performed at 110 ° C. for 60 seconds.
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. After development, post-baking was performed at 100 ° C. for 45 seconds.
As a result, in each example, a 1: 1 line and space (LS) pattern having a line width of 49 nm and a pitch of 98 nm was formed.

<Evaluation of resist pattern>
[Evaluation of mask error factor (MEEF)]
According to the same procedure as the formation of the LS pattern, an LS pattern having a pitch of 98 nm was formed using mask patterns having a line pattern target size of 45 to 54 nm (1 nm increments, 10 points in total) at the same exposure amount. At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the size (nm) of the line pattern formed on the resist film using each mask pattern was plotted on the vertical axis was calculated as MEEF. MEEF (straight line) means that the closer the value is to 1, the better the mask reproducibility. The results are shown in Table 38.

[LWR (line width roughness) evaluation]
In the above LS pattern, the space width was measured at 400 locations in the longitudinal direction of the space with a length measurement SEM (scanning electron microscope, acceleration voltage 300 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). A triple value (3 s) of the standard deviation (s) was obtained, and a value averaged over 3 s at 400 locations was calculated as a scale indicating LWR. The results are shown in Table 38.
The smaller this 3s value is, the smaller the roughness of the line width, which means that an LS pattern with a more uniform width was obtained.

[Evaluation of exposure margin (EL margin)]
With respect to the exposure amount at which the LS pattern is formed, the exposure amount when the line of the LS pattern is formed within the range of ± 5% of the target dimension was determined, and the EL margin (unit:%) was determined by the following equation. The results are shown in Table 38.
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
Note that the larger the value of the EL margin, the smaller the change amount of the pattern size accompanying the change in the exposure amount.
In the EL margin calculation formula, “Eop” means the optimum exposure amount (mJ / cm ² ). The Eop was determined by a conventional method.

[Evaluation of resist pattern shape]
The cross-sectional shape of the LS pattern formed by the above <formation of positive resist pattern> was observed using a scanning electron microscope (trade name: SU-8000, manufactured by Hitachi High-Technology Corporation), and the shape was evaluated as follows. Evaluation was made according to the criteria. The results are shown in Table 38.
○: Good with high rectangularity ×: T top shape or top round shape

  As shown in Table 38, Examples 1 to 3 were superior in EL margin, LWR, MEEF, and pattern shape to Comparative Example 1.

<Resist pattern formation 2; Examples 4 to 13 and Comparative Examples 2 to 3>
The above <resist pattern formation 1> except that the PEB treatment was performed at the temperatures shown in Table 39 for 60 seconds and the resist compositions (Examples 4 to 13 and Comparative Examples 2 to 3) shown in Table 35 were used, respectively. A resist pattern was formed by the same method.
As a result, in each example, a 1: 1 line and space (LS) pattern having a line width of 49 nm and a pitch of 98 nm was formed.

  For Examples 4 to 13 and Comparative Examples 2 to 3, EL margin, LWR, MEEF, and pattern shape were measured by the same method as described above. The results are shown in Table 39.

  As shown in Table 39, in Examples 4 to 13, the EL margin, LWR, MEEF, and pattern shape were superior to those of Comparative Examples 2 to 3.

<Resist pattern formation 3; Examples 14-17, Comparative Examples 4-5>
The above <resist pattern formation 1> except that the PEB treatment was performed at the temperatures shown in Table 40 for 60 seconds and the resist compositions (Examples 14 to 17 and Comparative Examples 4 to 5) shown in Table 36 were used, respectively. A resist pattern was formed by the same method.
As a result, in each example, a 1: 1 line and space (LS) pattern having a line width of 49 nm and a pitch of 98 nm was formed.

  Also in Examples 14 to 17 and Comparative Examples 4 to 5, the EL margin, LWR, MEEF, and pattern shape were measured by the same method as described above. The results are shown in Table 40.

  As shown in Table 40, Examples 14 to 17 were superior in EL margin, LWR, MEEF, and pattern shape to Comparative Examples 4 to 5.

<Formation of Resist Pattern 4; Examples 18-21, Comparative Examples 6-7>
The above <resist pattern formation 1> except that PEB treatment was performed at the temperature shown in Table 41 for 60 seconds and the resist compositions (Examples 18 to 21 and Comparative Examples 6 to 7) shown in Table 37 were used, respectively. A resist pattern was formed by the same method.
As a result, in each example, a 1: 1 line and space (LS) pattern having a line width of 49 nm and a pitch of 98 nm was formed.

  For Examples 18 to 21 and Comparative Examples 6 to 7, the EL margin, LWR, MEEF, and pattern shape were measured by the same method as described above. The results are shown in Table 41.

  As shown in Table 41, Examples 18 to 21 were superior in EL margin, LWR, MEEF, and pattern shape to Comparative Examples 6 to 7.

Claims (5)

The compound represented by the following general formula (a0-1).

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ² and Y ³ are each independently a single bond or a divalent linking group. R ² and R ³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ² or R 3 ^At least one of ³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n1 is an integer of 0-2. n2 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. X ⁺ is an organic cation or a metal cation. ] The high molecular compound which has the structural unit (a0) induced | guided | derived from the compound represented by the following general formula (a0-1).

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ² and Y ³ are each independently a single bond or a divalent linking group. R ² and R ³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ² or R 3 ^At least one of ³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n1 is an integer of 0-2. n2 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. X ⁺ is an organic cation or a metal cation. ] A resist composition that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid,
It contains a base material component (A ′) whose solubility in a developing solution is changed by the action of an acid, and the base material component (A ′) is derived from a compound represented by the following general formula (a0-11) A resist composition comprising a polymer compound (A1 ′) having a structural unit (a0).

[Wherein, R ¹¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ¹² and Y ¹³ are each independently a single bond or a divalent linking group. R ¹² and R ¹³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ¹² or R ^{13 At} least one of ¹³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n11 is an integer of 0-2. n12 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. M ⁺ is an organic cation. ] A resist composition containing a base material component (A) whose solubility in a developer is changed by the action of an acid, and an acid generator component (B ′) that generates an acid upon exposure,
The resist composition containing the acid generator (B1 ') in which the acid generator component (B') contains a compound represented by the following general formula (a0-11).

[Wherein, R ¹¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Y ¹² and Y ¹³ are each independently a single bond or a divalent linking group. R ¹² and R ¹³ are each independently a functional group or a group represented by the general formula (1-an1), (1-an2) or (1-an3), and R ¹² or R ^{13 At} least one of ¹³ is a group represented by the general formula (1-an1), (1-an2) or (1-an3). n11 is an integer of 0-2. n12 is 0 or 1.
Y ¹ is a single bond or —SO ₂ —, and R ⁵ 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. M ⁺ is an organic cation. ]   A step of forming a resist film on the support using the resist composition according to claim 3, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern are included. Resist pattern forming method.