JP6929070B2 - Resist composition and resist pattern forming method - Google Patents

Description

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

In the lithography technology, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed, and a development process is performed to form a resist pattern having a predetermined shape on the resist film. The process of performing is performed. A resist material whose exposed portion of the resist film changes to a characteristic of being soluble in a developing solution is referred to as a positive type resist material, and a resist material whose exposed portion of a resist film changes to a characteristic of not being dissolved in a developing solution is referred to as a negative type resist material.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization is rapidly progressing due to advances in lithography technology. As a miniaturization method, generally, the wavelength of the exposure light source is shortened (energy is increased). Specifically, in the past, ultraviolet rays typified by g-rays and i-rays were used, but nowadays, mass production of semiconductor devices using KrF excimer lasers and ArF excimer lasers is being carried out. Further, studies have been conducted on EUV (extreme ultraviolet), EB (electron beam), X-ray, etc., which have shorter wavelengths (higher energy) than these excimer lasers.

The resist material is required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern of fine dimensions.
Conventionally, as a resist material satisfying such a requirement, 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 by exposure. Is used.
For example, when the developer is an alkaline developer (alkali development process), the positive chemically amplified resist composition includes a resin component (base resin) whose solubility in the alkaline developer is increased by the action of an acid and acid generation. Those containing an agent component are generally used. When a resist film formed by using such a resist composition is selectively exposed at the time of forming a resist pattern, an acid is generated from an acid generator component in the exposed portion, and the polarity of the base resin is increased by the action of the acid. Then, the exposed portion of the resist film becomes soluble in the alkaline developing solution. Therefore, alkaline development forms a positive pattern in which the unexposed portion of the resist film remains as a pattern (see, for example, Patent Document 1).

Further, as a resist material, a chemically amplified resist conventionally containing a base component (alkali-soluble base component) soluble in an alkali developer, an acid generator component that generates an acid upon exposure, and a cross-linking agent component. Compositions have also been used. In such a chemically amplified resist composition, for example, when an acid is generated from an acid generator component by exposure, the acid acts to cause cross-linking between the alkali-soluble base material component and the cross-linking agent component, resulting in a result. Solubility in alkaline developer is reduced. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the chemically amplified resist composition on the support is selectively exposed, the resist film exposed portion turns into sparingly soluble in an alkaline developer. Since the unexposed portion of the resist film remains soluble in the alkaline developer and does not change, a negative resist pattern is formed by developing with the alkaline developer (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2003-241385 Japanese Unexamined Patent Publication No. 2007-084502

Further, in recent years, as resist patterns have become more and more miniaturized, for example, in lithography using an electron beam or EUV, the goal is to form a fine pattern of several tens of nanometers. As the resist pattern size becomes smaller as described above, the resist composition is required to have high resolution performance.
When an attempt is made to form a finer pattern using the positive-type chemically amplified resist composition described above, a region with weak optical intensity is generated in the exposed portion of the resist film, particularly in the film thickness direction, and the resolution of the resist pattern is resolved. There is a problem that the sex tends to deteriorate.
On the other hand, in order to form a pattern having fine dimensions as described above, a chemically amplified resist composition containing an alkali-soluble base material component, an acid generator component and a cross-linking agent component is used, and the optical intensity is weak. A method of selectively dissolving and removing the region to form a resist pattern (negative type resist pattern) is useful. However, in the conventional chemically amplified resist composition containing this cross-linking agent component, it cannot be said that the cross-linking property of the resist film exposed portion is high in forming a resist pattern using an electron beam or the like as an exposure light source, and the resolution performance is high. Was insufficient.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a resist composition and a resist pattern forming method in which resolution performance is improved, particularly in lithography using an electron beam or EUV. ..

In order to solve the above problems, the present invention has adopted the following configuration.
That is, the first aspect of the present invention is a resist composition in which an acid is generated by exposure and the solubility in a developing solution is changed by the action of the acid, and the solubility in the developing solution is changed by the action of the acid. The material component (A) and the fluoropolymer component (F) exhibiting degradability with respect to the alkaline developing solution are contained, and the base material component (A) is represented by the following general formula (a0-1). The fluororesin component (F) contains a fluororesin component (F1) having a structural unit (f1) containing a base dissociative group, and contains a polymer compound (A1) having a structural unit derived from the compound. It is a resist composition characterized by the above.

［式中、Ｒａ^ｘ０は重合性基含有基である。Ｗａ^ｘ０は、（ｎ_ａｘ０＋１）価の芳香族炭化水素基である。但し、Ｒａ^ｘ０とＷａ^ｘ０とで縮合環構造が形成されていてもよい。ｎ_ａｘ０は、１〜３の整数である。Ｙａ^ｘ０１は、カルボニル基又は単結合である。Ｒａ^ｘ０１は、置換基を有してもよい炭化水素基又は水素原子である。］

[In the formula, Ra ^x0 is a polymerizable group-containing group. Wa ^x0 is an aromatic hydrocarbon group having a (n _{ax0 + 1) valence.} However, a fused ring structure may be formed by ^{Ra x0} and Wa ^x0. n _ax0 is an integer of 1 to 3. Ya ^x01 is a carbonyl group or a single bond. Ra ^x01 is a hydrocarbon group or a hydrogen atom which may have a substituent. ]

A second aspect of the present invention is a step of forming a resist film on a support using the resist composition according to the first aspect, a step of exposing the resist film, and a step of exposing the resist film after the exposure. It is a resist pattern forming method characterized by having a step of forming a resist pattern by alkaline development.

According to the resist composition of the present invention, the resolution performance can be improved in lithography using an electron beam or EUV.
According to the resist pattern forming method of the present invention, a resist pattern having a high resolution and a good shape can be formed.

In the present specification and claims, "aliphatic" is defined as a concept relative to aromatics and means a group, a compound or the like having no aromaticity.
Unless otherwise specified, the "alkyl group" shall include linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the "alkylene group" shall include linear, branched and cyclic divalent saturated hydrocarbon groups.
The "alkyl halide group" is a group in which a part or all of the hydrogen atom of the alkyl group is 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.
The "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which a part or all of hydrogen atoms of an alkyl group or an alkylene group is substituted with a fluorine atom.
The “constituent unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
When it is described that "may have a substituent" or "may have a substituent", the case where the hydrogen atom (-H) is substituted with a monovalent group and the case where the methylene group (-CH _{2) is substituted.} Includes both cases where −) is replaced with a divalent group.
"Exposure" is a concept that includes general irradiation of radiation.

The “constituent unit derived from the acrylic acid ester” means a structural unit formed by cleaving the ethylenic double bond of the acrylic acid ester.
The "acrylic acid ester" is a compound in which the hydrogen atom at the terminal of the carboxy group of _{acrylic acid (CH 2 = CH-COOH) is replaced with an organic group.}
In the acrylic acid ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. ^{The substituent (R α0} ) that replaces the hydrogen atom bonded to the carbon atom at the α-position is an atom or group other than the hydrogen atom, for example, an alkyl group having 1 to 5 carbon atoms and a halogenation having 1 to 5 carbon atoms. Examples include an alkyl group. In addition, ^{an itaconic acid diester in which the substituent (R α0} ) is substituted with a substituent containing an ester bond, ^{and an α-hydroxyacrylic ester in which the substituent (R α0} ) is substituted with a hydroxyalkyl group or a group modified with a hydroxyl group thereof are also available. It shall include. Unless otherwise specified, the carbon atom at the α-position of the acrylic acid ester is a carbon atom to which the carbonyl group of acrylic acid is bonded.
Hereinafter, an acrylic acid 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 acrylic acid ester. Further, the acrylic acid ester and the α-substituted acrylic acid ester may be collectively referred to as “(α-substituted) acrylic acid ester”.

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

The “constituent unit derived from hydroxystyrene” means a structural unit formed by cleaving the ethylenic double bond of hydroxystyrene. The “constituent unit derived from the hydroxystyrene derivative” means a structural unit formed by cleaving the ethylenic double bond of the hydroxystyrene derivative.
The "hydroxystyrene derivative" is a concept including a hydrogen atom at the α-position of hydroxystyrene substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. As those derivatives, the hydrogen atom at the α-position may be substituted with a substituent. The hydrogen atom of the hydroxyl group of hydroxystyrene is substituted with an organic group; even if the hydrogen atom at the α-position is substituted with a substituent. Examples thereof include those in which a substituent other than a hydroxyl group is bonded to a good hydroxystyrene benzene ring. The α-position (carbon atom at the α-position) refers to a carbon atom to which a benzene ring is bonded unless otherwise specified.
Examples of the substituent substituting the hydrogen atom at the α-position of hydroxystyrene include those similar to those mentioned as the substituent at the α-position in the α-substituted acrylic acid ester.

The "constituent unit derived from vinyl benzoic acid or vinyl benzoic acid derivative" means a structural unit formed by cleaving the ethylenic double bond of vinyl benzoic acid or vinyl benzoic acid derivative.
The "vinyl benzoic acid derivative" is a concept including those 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. Derivatives thereof include those in which the hydrogen atom at the α-position may be substituted with a substituent, and the hydrogen atom of the carboxy group of vinyl benzoic acid is substituted with an organic group; the hydrogen atom at the α-position is substituted with a substituent. Examples thereof include those in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinyl benzoic acid. The α-position (carbon atom at the α-position) refers to a carbon atom to which a benzene ring is bonded unless otherwise specified.

The concept of "styrene" includes styrene and those in which the hydrogen atom at the α-position of styrene is substituted with another substituent such as an alkyl group or an alkyl halide group.
The "styrene derivative" is a concept including a hydrogen atom at the α-position of styrene substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. Examples of these derivatives include those in which a substituent is bonded to the benzene ring of hydroxystyrene in which the hydrogen atom at the α-position may be substituted with a substituent. The α-position (carbon atom at the α-position) refers to a carbon atom to which a benzene ring is bonded unless otherwise specified.
“Constituent unit derived from styrene” and “constituent unit derived from a styrene derivative” mean a structural unit formed by cleaving an ethylenic double bond of styrene or a styrene derivative.

The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, and 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.
Further, the alkyl halide group as the substituent at the α-position is specifically a group in which a part or all of the hydrogen atom of the above-mentioned "alkyl group as the substituent at the α-position" is substituted with a halogen atom. Be done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferable.
Further, as the hydroxyalkyl group as the substituent at the α-position, specifically, a group in which a part or all of the hydrogen atom of the above-mentioned "alkyl group as the substituent at the α-position" is substituted with a hydroxyl group can be mentioned. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

(Resist composition)
The resist composition according to the first aspect of the present invention generates an acid by exposure, and the solubility in a developing solution is changed by the action of the acid.
As one embodiment of such a resist composition, a base material component (A) whose solubility in a developing solution is changed by the action of an acid (hereinafter, also referred to as “component (A)”) and a degradability to an alkaline developing solution. Examples thereof include a resist composition containing the fluorine additive component (F) (hereinafter, also referred to as “(F) component”) showing the above.
In the resist composition of the present embodiment, the component (A) is a polymer compound (A1) having a structural unit derived from the compound represented by the general formula (a0-1) (hereinafter referred to as “component (A1)”). ), And the component (F) includes a fluororesin component (F1) having a structural unit (f1) containing a base dissociable group (hereinafter referred to as “(F1) component”).

When a resist film is formed using the resist composition of the present embodiment and selective exposure is performed on the resist film, an acid is generated in the exposed portion of the resist film, and the component (A) is generated by the action of the acid. While the solubility of the resist film in the developing solution changes, the solubility of the component (A) in the developing solution does not change in the unexposed portion of the resist film. There is a difference in solubility against. Therefore, when the resist film is alkaline-developed, the unexposed portion of the resist film is dissolved and removed to form a negative resist pattern.

In the present specification, a resist composition in which a resist film exposed portion is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist film unexposed portion is dissolved and removed to form a negative resist pattern. The resist composition to be used is called a negative resist composition. The resist composition of the present embodiment is suitable for an alkaline development process in which an alkaline developer is used for the development treatment at the time of forming a resist pattern.

The resist composition of the present embodiment has an acid-generating ability to generate an acid by exposure, and the component (A) may generate an acid by exposure, and is added separately from the component (A). The agent component may generate an acid upon exposure.
Specifically, the resist composition of the embodiment may contain (1) an acid generator component (B) (hereinafter referred to as "component (B)") that generates an acid by exposure; (2) The component (A) may be a component that generates an acid by exposure; the component (3) (A) is a component that generates an acid by exposure and further contains the component (B). It may be.
That is, in the case of the above (2) or (3), the component (A) is "a base material component that generates an acid by exposure and whose solubility in a developing solution changes by the action of the acid". When the component (A) is a base material component that generates an acid by exposure and whose solubility in a developing solution changes due to the action of the acid, the component (A1) described later generates an acid by exposure and the solubility in the developer changes. It is preferably a polymer compound whose solubility in a developing solution changes due to the action of an acid. As such a polymer compound, a resin having a structural unit that generates an acid upon exposure can be used. Known monomers can be used as the monomer for inducing the structural unit that generates an acid by exposure. The resist composition of the present embodiment is particularly preferably the case of (1) above.

<Ingredient (A)>
The component (A) is a base material component whose solubility in a developing solution changes due to the action of an acid.
In the present invention, the "base material component" is an organic compound having a film-forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved, and in addition, it becomes easy to form a nano-level resist pattern.
Organic compounds used as base material components are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the term "small molecule compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, a polymer having a molecular weight of 1000 or more is usually used. Hereinafter, the terms "resin", "polymer compound" or "polymer" indicate a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, the polystyrene-equivalent weight average molecular weight by GPC (gel permeation chromatography) shall be used.

In the resist composition of the present embodiment, the component (A) has a structural unit derived from the compound represented by the general formula (a0-1) (hereinafter, this is referred to as “constituent unit (a0)”). At least the polymer compound (A1) is used, and a polymer compound and / or a low molecular weight compound other than the component (A1) may be used in combination.
When a resist film is formed using a resist composition containing at least the component (A1) and the resist film is selectively exposed, for example, the resist composition is (B) in the exposed portion of the resist film. ) Is contained, an acid is generated from the component (B), and the action of the acid causes cross-linking between the components (A1) via the cross-linking structural unit (a0). The solubility of the resist film exposed portion in an alkaline developer is reduced. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the resist composition of the present embodiment on the support is selectively exposed, the resist film exposed portion becomes sparingly soluble in the alkaline developing solution. Since the unexposed portion of the resist film remains soluble in the alkaline developing solution and does not change, a negative resist pattern is formed by developing with the alkaline developing solution.

-Regarding the component (A1) The component (A1) is a polymer compound having a structural unit (constituent unit (a0)) derived from the compound represented by the general formula (a0-1).
As the component (A1), a copolymer having a structural unit (a10) containing an aromatic ring to which a hydroxy group is bonded in a side chain is preferable in addition to the structural unit (a0).
As the component (A1), in addition to the structural unit (a0), or in addition to the structural unit (a0) and the structural unit (a10), an aromatic ring (excluding an aromatic ring to which a hydroxy group is bonded) is further sided. A copolymer having a structural unit (a11) contained in the chain is preferable.
Further, the component (A1) may have other constituent units other than the constituent unit (a0), the constituent unit (a10), and the constituent unit (a11).

<< Structural unit (a0) >>
The structural unit (a0) is a structural unit derived from the compound represented by the following general formula (a0-1) and has crosslinkability.

［式中、Ｒａ^ｘ０は重合性基含有基である。Ｗａ^ｘ０は、（ｎ_ａｘ０＋１）価の芳香族炭化水素基である。但し、Ｒａ^ｘ０とＷａ^ｘ０とで縮合環構造が形成されていてもよい。ｎ_ａｘ０は、１〜３の整数である。Ｙａ^ｘ０１は、カルボニル基又は単結合である。Ｒａ^ｘ０１は、置換基を有してもよい炭化水素基又は水素原子である。］

[In the formula, Ra ^x0 is a polymerizable group-containing group. Wa ^x0 is an aromatic hydrocarbon group having a (n _{ax0 + 1) valence.} However, a fused ring structure may be formed by ^{Ra x0} and Wa ^x0. n _ax0 is an integer of 1 to 3. Ya ^x01 is a carbonyl group or a single bond. Ra ^x01 is a hydrocarbon group or a hydrogen atom which may have a substituent. ]

In the formula (a0-1), Ra ^x0 is a polymerizable group-containing group.
The "polymerizable group" in Ra ^x0 is a group that enables a compound having a polymerizable group to be polymerized by radical polymerization or the like, and is a group containing multiple bonds between carbon atoms such as an ethylenic double bond. To say.
Examples of the polymerizable group include a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a fluorovinyl group, a difluorovinyl group, a trifluorovinyl group, a difluorotrifluoromethylvinyl group, a trifluoroallyl group, a perfluoroallyl group, and a tri. Fluoromethylacryloyl group, nonylfluorobutylacryloyl group, vinyl ether group, fluorine-containing vinyl ether group, allyl ether group, fluorine-containing allyl ether group, styryl group, vinylnaphthyl group, fluorine-containing styryl group, fluorine-containing vinylnaphthyl group, norbornyl group, Examples thereof include a fluorine-containing norbornyl group and a silyl group.
The polymerizable group-containing group may be a group composed of only a polymerizable group, or a group composed of a polymerizable group and a group other than the polymerizable group. Examples of the group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like.

As Ra ^x0 , for example, a group represented by the chemical formula: CH ₂ = C (R) -Ya ^{x0-is preferably mentioned.} In this chemical formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms, and Ya ^x0 is a divalent linking group.

In the above chemical formula, the alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, and the like. Examples thereof include isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The alkyl halide group having 1 to 5 carbon atoms is a group in which a 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, an iodine atom and the like, and a fluorine atom is particularly preferable. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom and a methyl group are particularly preferable from the viewpoint of industrial availability.

In the above chemical formula, the ^{divalent linking group at Ya x0} is not particularly limited, but a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, or the like is preferable. Is listed as.

A divalent hydrocarbon group that may have a substituent:
When Ya ^x0 is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

· · ^{Aliphatic hydrocarbon group in Ya x0} The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

... Linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. Numbers 1 to 4 are more preferable, and carbon numbers 1 to 3 are most preferable.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [−CH ₂ −], an ethylene group [− (CH ₂ ) ₂ −], and a trimethylene group [ − (CH ₂ ) ₃ −], tetramethylene group [− (CH ₂ ) ₄ −], pentamethylene group [− (CH ₂ ) ₅ −] and the like can be mentioned.
The branched-chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, and -C (CH ₃ ). Alkylene methylene groups such as _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) _{2-, etc.;-} 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) Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ − and −CH ₂ CH (CH ₃ ) CH ₂ CH _{2 −.} As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

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, a carbonyl group and the like.

... An aliphatic hydrocarbon group containing a ring in the structure As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group may contain a substituent containing a hetero atom in the ring structure. (A group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which the cyclic aliphatic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group, the cyclic fat Examples thereof include a group in which a group hydrocarbon group is present in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same groups as described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples 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 is preferably a polycycloalkane having 7 to 12 carbon atoms, specifically. Examples thereof include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

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

Aromatic hydrocarbon group in Ya ^x0 The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be a monocyclic type or a polycyclic type. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent.
Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced with heteroatoms. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings. A group obtained by removing two hydrogen atoms from (for example, biphenyl, fluorene, etc.); one of the hydrogen atoms of the group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring. Hydrogen from an aryl group in an arylalkyl group such as a group substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group). A group obtained by removing one more atom) and the like. The alkylene group bonded to the aryl group or the heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon number.

In the aromatic hydrocarbon group, the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group and the like.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are more preferable.
Examples of the alkoxy group, halogen atom and alkyl halide 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 heteroatom:
When Ya ^x0 is a divalent linking group containing a hetero atom, the preferred linking groups are -O-, -C (= O) -O-, -OC (= O)-,-. C (= O)-, -OC (= O) -O-, -C (= O) -NH-, -NH-, -NH-C (= NH)-(H is an alkyl group, an acyl group) may be substituted with substituent _{such), -. S -, -} S (= O) 2 -, - S (= O) 2 -O-, the formula ^-Y 21 ^{-O-Y 22} -, ^{-Y 21 -O -, - Y 21} -C (= O) -O -, - C (= O) -O-Y 21 -, - [Y 21 -C (= O) -O] m "-Y ^{22 -, - Y 21 -O-} C (= O) -Y 22 - or _{^{-Y 21 -S (= O) 2}} -O-Y 22 - group represented by ^{wherein, Y 21} and ^{Y 22} Each is a divalent hydrocarbon group which may have a substituent independently, O is an oxygen atom, and m "is an integer of 0 to 3. ] Etc. can be mentioned.
The divalent linking group containing the hetero atom is -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH). In the case of −, the H may be substituted with a substituent such as an alkyl group or an acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 -C (= O) -O -, - C (= O) -O-Y 21 -, - [Y 21 - _{^{C (= O) -O] m}} "-Y 22 -, - Y 21 -O-C (= O) -Y 22 - or _{^{-Y 21 -S (= O) 2}} -O-Y 22 - in, Y ²¹ and Y ²² are divalent hydrocarbon groups which may independently have a substituent. The divalent hydrocarbon group is mentioned in the description as the divalent linking group. (A divalent hydrocarbon group which may have a substituent) is mentioned.
As Y ²¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is particularly preferable. preferable.
As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkyl methylene group is more preferable. 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.
Formula _{^{- [Y 21 -C (= O}} ) -O] m "-Y 22 - In the group represented by, m" is an integer of 0 to 3, preferably an integer of 0 to 2, 0 Or 1 is more preferable, and 1 is particularly preferable. In other words, the formula ^- Examples of the group represented by the formula ^{-Y 21 -C (= O) -O} -Y 22 - - [Y 21 -C (= O) -O] m "-Y 22 represented by A group is particularly preferable. Among _{them, a group represented by the formula − (CH 2} ) _{a ′} −C (= O) −O− (CH ₂ ) _{b ′} − is preferable. In the formula, a ′ is 1 to 1. It is an integer of 10, preferably an integer of 1-8, more preferably an integer of 1-5, even more preferably 1 or 2, and most preferably 1. b'is an integer of 1-10, 1-8. Is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is more preferable, and 1 is most preferable.

Among the above, ^{as Ya x0} , a single bond, an ester bond [-C (= O) -O-, -OC (= O)-], an ether bond (-O-), a linear or branched chain It is preferably a alkylene group having a shape, or a combination thereof, and more preferably a single bond or an ester bond [-C (= O) -O-, -O-C (= O)-].

In the formula (a0-1), Wa ^x0 is an aromatic hydrocarbon group having a (n _{ax0 + 1) valence.}
Examples of the aromatic hydrocarbon group in Wa ^x0 include a group obtained by removing _{(n ax0 + 1) hydrogen atoms from the aromatic ring.} The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be a monocyclic type or a polycyclic type. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specifically, the aromatic ring is an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, or phenanthrene; an aromatic heterocycle in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom or the like. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Further, ^{examples of the aromatic hydrocarbon group in Wa x0} include a group obtained by removing _{(n ax0} + 1) hydrogen atoms from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.).

However, a fused ring structure may be formed by ^{Ra x0} and Wa ^x0.
When a fused ring structure is formed by ^{Ra x0} and Wa ^x0 , the fused ring structure includes an aromatic ring derived from ^{Wa x0.} In addition, ^{the multiple bonds between carbon atoms of the polymerizable group derived from Ra x0} are cleaved to form the main chain of the component (A1). That is, a part of the carbon atoms constituting the fused ring constitutes the main chain of the component (A1).

In the above formula (a0-1), n _ax0 is an integer of 1 to 3, preferably 1 or 2.

In the above formula (a0-1), Ya ^x01 is a carbonyl group or a single bond, and a single bond is preferable.

In the formula (a0-1), Ra ^x01 is a hydrocarbon group or a hydrogen atom which may have a substituent.
The hydrocarbon group in Ra ^x01 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Examples of Ra ^x01 include an alkyl group, a monovalent alicyclic hydrocarbon group, an aryl group, and an aralkyl group.

The alkyl group in Ra ^x01 preferably has 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, further preferably 1 to 3 carbon atoms, and may be linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group and the like are preferable, a methyl group, an ethyl group and a propyl group are more preferable, and a methyl group is particularly preferable.

The ^{monovalent alicyclic hydrocarbon group in Ra x01} preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms, and may be a polycyclic type or a monocyclic type. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclobutane, cyclopentane, and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms. Examples include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aryl group in Ra ^x01 preferably has 6 to 18 carbon atoms, more preferably 6 to 10 carbon atoms, and specifically preferably a phenyl group.

As ^{the aralkyl group in Ra x01,} an aralkyl group in which an alkylene group having 1 to 8 carbon atoms and the above-mentioned " ^{aryl group in Ra x01} " are bonded is preferable, and an alkylene group having 1 to 6 carbon atoms and the above-mentioned aryl group in ^{Ra x01 are preferable.} Is more preferable, and an aralkyl group in which an alkylene group having 1 to 4 carbon atoms and the above-mentioned " ^{aryl group in Ra x01} " is bonded is particularly preferable.

Among the above, Ra ^x01 is preferably an aliphatic hydrocarbon group or a hydrogen atom, more preferably an alkyl group or a hydrogen atom, and further preferably an alkyl group having 1 to 5 carbon atoms or a hydrogen atom. Methyl groups and hydrogen atoms are particularly preferable.

The hydrocarbon group in Ra ^x01 may have a substituent. Examples of the substituent include a halogen atom, an oxo group (= O), a hydroxyl group (-OH), an amino group (-NH ₂ ), -SO _2- NH _{2 and the} like. Further, a part of the carbon atom (methylene group) constituting the hydrocarbon group in ^{Ra x01 may be substituted with a substituent containing a heteroatom.} Substituents containing the heteroatom include -O-, -NH-, -N =, -C (= O) -O-, -S-, -S (= O) _{2-, -S (= O).} ) _2- O- can be mentioned.

A preferable specific example of the above-mentioned structural unit (a0) is a structural unit represented by the following general formula (a0-u1).

［式中、Ｒ^αは、水素原子、メチル基又はトリフルオロメチル基である。Ｙａ^ｘ０’は、ヘテロ原子を含む２価の連結基又は単結合である。Ｗａ^ｘ０は、（ｎ_ａｘ０＋１）価の芳香族炭化水素基である。ｎ_ａｘ０は、１〜３の整数である。Ｙａ^ｘ０１は、カルボニル基又は単結合である。Ｒａ^ｘ０１’は、炭素数１〜５のアルキル基又は水素原子である。］

[In the formula, R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group. Ya ^{x0'is a} divalent linking group or single bond containing a heteroatom. Wa ^x0 is an aromatic hydrocarbon group having a (n _{ax0 + 1) valence.} n _ax0 is an integer of 1 to 3. Ya ^x01 is a carbonyl group or a single bond. Ra ^x01'is an alkyl group or a hydrogen atom having 1 to 5 carbon atoms. ]

In the formula (a0-u1), R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group. Of these, R ^α is preferably a hydrogen atom or a methyl group.

In the formula (a0-u1), Ya ^{x0'is a} divalent linking group or a single bond containing a heteroatom.
The divalent linking group containing a heteroatom in ^{Ya x0'is the same} as the divalent linking group containing a heteroatom in ^{Ya x0.} Among them, Ya ^{x0'preferably} a single bond or an ester bond [-C (= O) -O-, -O-C (= O)-].

In the formula _{^{(a0-u1), Wa x0}} , n ax0, Ya x01 are respectively similar to ^{Wa _x0,} n _ax0, ^{Ya x01} of the above formula (a0-1) in.

In the above formula (a0-u1), Ra ^x01'is an alkyl group or a hydrogen atom having 1 to 5 carbon atoms, preferably a methyl group or a hydrogen atom, and more preferably a hydrogen atom.

As the structural unit represented by the above general formula (a0-u1), for example, the structural units represented by the following general formulas (a0-u1-1) to (a0-u1-9) are preferably mentioned. Be done.

［式中、Ｒ^αは、水素原子、メチル基又はトリフルオロメチル基である。ｎ_ａｘ０は、１〜３の整数である。ｎ_０１、ｎ_０２、ｎ_０４及びｎ_０５は、それぞれ独立に、０又は１である。ｎ_０３及びｎ_０６は、それぞれ独立に、１又は２である。］

[In the formula, R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group. n _ax0 is an integer of 1 to 3. n ₀₁ , n ₀₂ , n ₀₄ and n ₀₅ are independently 0 or 1, respectively. n ₀₃ and n ₀₆ are 1 or 2 independently of each other. ]

［式中、Ｒ^αは、水素原子、メチル基又はトリフルオロメチル基である。ｎ_ａｘ０は、１〜３の整数である。ｎ_０７、ｎ_０８、ｎ_０１０及びｎ_０１１は、それぞれ独立に、０又は１である。ｎ_０９及びｎ_０１２は、それぞれ独立に、１又は２である。］

[In the formula, R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group. n _ax0 is an integer of 1 to 3. n ₀₇ , n ₀₈ , n ₀₁₀ and n ₀₁₁ are independently 0 or 1, respectively. n ₀₉ and n ₀₁₂ are 1 or 2 independently of each other. ]

Specific examples of the structural unit (constituent unit (a0)) derived from the compound represented by the general formula (a0-1) are shown below.
In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

Further, as the above-mentioned structural unit (a0), a structural unit represented by the following general formula (a0-u1-10) is also preferably mentioned. A specific example of this is also shown below. In the following formula, n _ax0 is an integer of 1 to 3.

In the above examples, the structural unit (a0) is represented by the structural unit represented by the general formula (a0-u1-1) and the general formulas (a0-u1-5) to (a0-u1-10), respectively. Constituent units are preferred.
Among these, the chemical formulas (a0-u1-11) to (a0-u1-13), (a0-u1-51) to (a0-u1-53), (a0-u1-61), (a0-u1- The structural unit represented by either (81) or (a0-u1-101) is particularly preferable.

The structural unit (a0) contained in the component (A1) may be one type or two or more types.
The ratio of the constituent unit (a0) in the component (A1) is preferably 5 to 50 mol%, preferably 10 to 40 mol%, based on the total (100 mol%) of all the constituent units constituting the component (A1). More preferably, 15 to 30 mol% is further preferable.
By setting the ratio of the structural unit (a0) to the lower limit value or more, the resolution performance of the resist composition is further enhanced. On the other hand, by setting the value to the upper limit or less, it becomes easier to balance with other constituent units.

<< Structural unit (a10) >>
The component (A1) is preferably a copolymer having a structural unit (a10) derived from a compound having an aromatic ring bonded to a hydroxy group in the side chain, in addition to the structural unit (a0) described above.
As the compound containing an aromatic ring to which a hydroxy group is bonded in the side chain, for example, a compound represented by the following general formula (a10-1) is preferably used.

［式（ａ１０−１）中、Ｒａ^ｘ１は重合性基含有基である。Ｗａ^ｘ１は、（ｎ_ａｘ１＋１）価の芳香族炭化水素基である。但し、Ｒａ^ｘ１とＷａ^ｘ１とで縮合環構造が形成されていてもよい。ｎ_ａｘ１は、１〜３の整数である。］

[In the formula (a10-1), Ra ^x1 is a polymerizable group-containing group. Wa ^x1 is a (n _ax1 + 1) valent aromatic hydrocarbon group. However, a fused ring structure may be formed by ^{Ra x1} and Wa ^x1. n _ax1 is an integer of 1 to 3. ]

In the formula (a10-1), Ra ^x1 is a polymerizable group-containing group, and examples thereof include those similar to ^{Ra x0 in the formula (a0-1).}
In the formula (a10-1), Wa ^x1 is an aromatic hydrocarbon group having a (n _ax1 + 1) valence, and examples thereof include those similar to ^{Wa x0 in the above formula (a0-1).}

However, a fused ring structure may be formed by ^{Ra x1} and Wa ^x1.
When a fused ring structure is formed by ^{Ra x1} and Wa ^x1 , the fused ring structure includes an aromatic ring derived from ^{Wa x1.} In addition, ^{the multiple bonds between carbon atoms of the polymerizable group derived from Ra x1} are cleaved to form the main chain of the component (A1). That is, a part of the carbon atoms constituting the fused ring constitutes the main chain of the component (A1).

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

A preferable specific example of the above-mentioned structural unit (a10) is a structural unit represented by the following general formula (a10-u1).

［式中、Ｒ^αは、水素原子、メチル基又はトリフルオロメチル基である。Ｙａ^ｘ１は、ヘテロ原子を含む２価の連結基又は単結合である。Ｗａ^ｘ１は、（ｎ_ａｘ１＋１）価の芳香族炭化水素基である。ｎ_ａｘ１は、１〜３の整数である。］

[In the formula, R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group. Ya ^x1 is a divalent linking group or a single bond containing a heteroatom. Wa ^x1 is a (n _ax1 + 1) valent aromatic hydrocarbon group. n _ax1 is an integer of 1 to 3. ]

In the formula (a10-u1), R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group. Of these, R ^α is preferably a hydrogen atom or a methyl group.

In the formula (a10-u1), Ya ^x1 is a divalent linking group or a single bond containing a heteroatom.
The ^{divalent linking group containing a heteroatom in Ya x1} is the same as the divalent linking group containing a heteroatom in Ya ^x0 . Among them, Ya ^x1 is preferably a single bond or an ester bond [-C (= O) -O-, -O-C (= O)-].

In the formula (a10-u1), Wa ^x1 is an aromatic hydrocarbon group having a (n _{ax1 + 1) valence.} Examples of the aromatic hydrocarbon group in Wa ^x1 include a group obtained by removing _{(n ax1 + 1) hydrogen atoms from the aromatic ring.} The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be a monocyclic type or a polycyclic type. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specifically, the aromatic ring is an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, or phenanthrene; an aromatic heterocycle in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom or the like. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Further, ^{examples of the aromatic hydrocarbon group in Wa x1} include a group obtained by removing _{(n ax1} + 1) hydrogen atoms from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.).

In the above formula (a10-u1), n _ax1 is an integer of 1 to 3, preferably 1 or 2.

As the structural unit represented by the above general formula (a10-u1), for example, the structural units represented by the following general formulas (a10-u1-1) to (a10-u1-4) are preferably mentioned. Be done.

［式中、Ｒ^αは、水素原子、メチル基又はトリフルオロメチル基である。ｎ_ａｘ１は、１〜３の整数である。ｎ_１１、ｎ_１２、ｎ_１４及びｎ_１５は、それぞれ独立に、０又は１である。ｎ_１３及びｎ_１６は、それぞれ独立に、１又は２である。］

[In the formula, R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group. n _ax1 is an integer of 1 to 3. n ₁₁ , n ₁₂ , n ₁₄ and n ₁₅ are independently 0 or 1, respectively. n ₁₃ and n ₁₆ are independently 1 or 2, respectively. ]

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

Among the above examples, the structural unit (a10) is preferably at least one selected from the group consisting of the structural units represented by the general formulas (a10-u1-1) to (a10-u1-4), and is generally used. The structural unit represented by the formula (a10-u1-1) is more preferable.
Among these, the structural unit (a10) is represented by any of the chemical formulas (a10-u1-11), (a10-u1-21), (a10-u1-31) or (a10-u1-41). Constituent units are preferred.

The structural unit (a10) contained in the component (A1) may be one type or two or more types.
When the component (A1) has a constituent unit (a10), the ratio of the constituent unit (a10) in the component (A1) is relative to the total (100 mol%) of all the constituent units constituting the component (A1). It is preferably 50 to 90 mol%, more preferably 55 to 80 mol%, and particularly preferably 60 to 70 mol%.
By setting the ratio of the structural unit (a10) to the lower limit value or more, the development characteristics and the lithography characteristics are further improved. On the other hand, by setting the value to the upper limit or less, it becomes easier to balance with other constituent units.

<< Structural unit (a11) >>
The component (A1) further comprises an aromatic ring (excluding an aromatic ring to which a hydroxy group is bonded) in addition to the above-mentioned structural unit (a0) or in addition to the structural unit (a0) and the structural unit (a10). A copolymer having a structural unit (a11) derived from the compound contained in the side chain is preferable.
As the compound containing an aromatic ring (excluding the aromatic ring to which a hydroxy group is bonded) in the side chain, for example, a compound represented by the following general formula (a11-1) is preferably mentioned.

［式（ａ１１−１）中、Ｒａ^ｘ２は重合性基含有基である。Ｗａ^ｘ２は、（ｎ_ａｘ２＋１）価の芳香族炭化水素基である。但し、Ｒａ^ｘ２とＷａ^ｘ２とで縮合環構造が形成されていてもよい。Ｒａ^ｘ０２は、Ｗａ^ｘ２（芳香族炭化水素基）を構成する水素原子を置換する置換基である。ｎ_ａｘ２は、０〜３の整数である。ｎ_ａｘ２が２以上の場合、複数のＲａ^ｘ０２が相互に結合して環構造を形成してもよい。］

[In the formula (a11-1), Ra ^x2 is a polymerizable group-containing group. Wa ^x2 is a (n _ax2 + 1) valent aromatic hydrocarbon group. However, a fused ring structure may be formed by ^{Ra x2} and Wa ^x2. Ra ^x02 is a substituent that replaces a hydrogen atom constituting ^{Wa x2 (aromatic hydrocarbon group).} n _ax2 is an integer from 0 to 3. When n _ax 2 is 2 or more, a plurality of Ra ^{x 02} may be bonded to each other to form a ring structure. ]

In the formula (a11-1), Ra ^x2 is a polymerizable group-containing group, and examples thereof include those similar to ^{Ra x0 in the formula (a0-1).}
In the formula (a11-1), Wa ^x2 is an aromatic hydrocarbon group having a (n _ax2 + 1) valence, and examples thereof include those similar to ^{Wa x0 in the above formula (a0-1).}

However, a fused ring structure may be formed by ^{Ra x2} and Wa ^x2.
When a fused ring structure is formed by ^{Ra x2} and Wa ^x2 , the fused ring structure includes an aromatic ring derived from ^{Wa x2.} In addition, ^{the multiple bonds between carbon atoms of the polymerizable group derived from Ra x2} are cleaved to form the main chain of the component (A1). That is, a part of the carbon atoms constituting the fused ring constitutes the main chain of the component (A1).

In the above formula (a11-1), Ra ^x02 is a substituent that replaces a hydrogen atom constituting ^{Wa x2 (aromatic hydrocarbon group).
Examples} of the substituent in Ra x02 include an alkyl group, an alkoxy group, and an acyloxy group.
The alkyl group as the substituent in Ra ^x02 is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.
The alkoxy group as the substituent in Ra ^x02 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. , Methoxy group and ethoxy group are particularly preferable.
The acyloxy group as a substituent in Ra ^x02 preferably has 2 to 6 carbon atoms, and is preferably CH ₃ C (= O) -O- (acetoxy group) and C ₂ H ₅ C (= O) -O. -Is more preferable, and CH ₃ C (= O) -O- (acetoxy group) is particularly preferable.

In the above formula (a11-1), n _ax2 is an integer of 0 to 3, preferably 0, 1 or 2, and more preferably 0 or 1.
When n _ax 2 is 2 or more, a plurality of Ra ^{x 02} may be bonded to each other to form a ring structure. The ring structure formed here may be a hydrocarbon ring or a heterocycle. For example, two ^{Ra x02} attached to the same aromatic ring in ^{Wa x2,} and one side of the aromatic ring ^{(Wa x2)} of the two ^{Ra x02} binds (bond between carbon atoms), the ring structure formed include the Be done.

As the structural unit (a11), for example, the structural units represented by the following general formulas (a11-u1-1) to (a11-u1-6) are preferably mentioned.

［式中、Ｒ^αは、水素原子、メチル基又はトリフルオロメチル基である。Ｒ^βは、アルキル基、アルコキシ基又はアシルオキシ基である。ｎ_ａｘ２は、０〜３の整数である。ｎ_ａｘ２が２以上の場合、複数のＲ^βが相互に結合して、環構造を形成してもよい。ｎ_２１、ｎ_２２、ｎ_２４及びｎ_２５は、それぞれ独立に、０又は１である。ｎ_２３及びｎ_２６は、それぞれ独立に、１又は２である。］

[In the formula, R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group. ^Rβ is an alkyl group, an alkoxy group or an acyloxy group. n _ax2 is an integer from 0 to 3. If n _ax2 is 2 or more, plural R ^beta are bonded to each other, they may form a ring structure. n ₂₁ , n ₂₂ , n ₂₄ and n ₂₅ are independently 0 or 1, respectively. n ₂₃ and n ₂₆ are independently 1 or 2, respectively. ]

In the above formulas (a11-u1-1) to (a11-u1-6), the alkyl group, the alkoxy group and the acyloxy group in ^{R β} are exemplified as the substituent in ^{Ra x02 in the above formula (a11-1).} It is the same as the alkyl group, the alkoxy group and the acyloxy group.

Specific examples of the structural unit (constituent unit (a11)) derived from the compound represented by the general formula (a11-1) are shown below.
In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

Among the above examples, the structural unit (a11) is preferably at least one selected from the group consisting of the structural units represented by the general formulas (a11-u1-1) to (a11-u1-3), and is generally used. The structural unit represented by the formula (a11-u1-1) is more preferable.
Among these, the structural unit (a11) is preferably a structural unit represented by any of the chemical formulas (a11-u1-11), (a11-u1-21) or (a11-u1-31).

The structural unit (a11) contained in the component (A1) may be one type or two or more types.
When the component (A1) has a constituent unit (a11), the ratio of the constituent unit (a11) in the component (A1) is relative to the total (100 mol%) of all the constituent units constituting the component (A1). It is preferably 5 to 40 mol%, more preferably 10 to 35 mol%, and particularly preferably 10 to 30 mol%.
By setting the ratio of the structural unit (a11) to the lower limit value or more, the etching resistance and the lithography characteristics are further improved. On the other hand, by setting the value to the upper limit or less, it becomes easier to balance with other constituent units.

≪Other structural units≫
The component (A1) may have other structural units other than the structural unit (a0), the structural unit (a10), and the structural unit (a11).
Examples of the compound that induces such other constituent units include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; 2-methacryloyloxyethyl succinic acid, 2-. Methacrylic acid derivatives having carboxy groups and ester bonds such as methacryloyloxyethyl maleic acid, 2-methacryloyloxyethylphthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (Meta) acrylic acid alkyl esters such as (meth) acrylate; (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; phenyl (meth) acrylate, (Meta) acrylic acid aryl esters such as benzyl (meth) acrylate; Dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; Vinyl group-containing aliphatic compounds such as vinyl acetate; Conjugate diolefins such as butadiene and isoprene Classes; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; amide bond-containing polymerizable compounds such as acrylamide and methacrylicamide; epoxy group-containing polymerizable compounds. Kind and the like.

In the resist composition of the present embodiment, the component (A) contains the polymer compounds (A1) (component (A1)) having the structural unit (a0).
Preferred (A1) components include polymer compounds having at least a structural unit (a0) and a structural unit (a10). Specifically, a polymer compound having a repeating structure of a structural unit (a0) and a structural unit (a10), and a high molecular compound having a repeating structure of the structural unit (a0), the structural unit (a10), and the structural unit (a11). Molecular compounds are preferred.

The weight average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, and is preferably 500 to 50,000, more preferably 1,000 to 30,000, and more preferably 2000 to 30,000. 20000 is even more preferred.
When the Mw of the component (A1) is not more than a preferable upper limit value in this range, there is sufficient solubility in a resist solvent to be used as a resist, and when it is not more than a preferable lower limit value in this range, dry etching resistance and dry etching resistance are increased. The cross-sectional shape of the resist pattern becomes better.

The dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.5 to 2.5. .. Mn indicates a number average molecular weight.

As the component (A1) contained in the resist composition of the present embodiment, one type may be used alone, or two or more types may be used in combination.
In the resist composition of the present embodiment, as the component (A), a base material component that does not correspond to the component (A1) and whose solubility in a developing solution changes due to the action of an acid may be used in combination.
The ratio of the component (A1) to the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, further preferably 75% by mass or more, and 100% by mass with respect to the total mass of the component (A). It may be. When the proportion of the component (A1) is 25% by mass or more, a resist pattern excellent in various lithography characteristics such as high sensitivity, resolution, and roughness improvement is likely to be formed. Such an effect is particularly remarkable in lithography using an electron beam or EUV.

In the component (A1), a monomer inducing each structural unit is dissolved in a polymerization solvent, and here, for example, azobisisobutyronitrile (AIBN) and dimethyl 2,2'-azobisisobutyrate (for example, V-601) are dissolved. It can be produced by adding a radical polymerization initiator such as) and polymerizing. Incidentally, during the polymerization, for example, by using a combination of chain transfer agent such as _{HS-CH 2 -CH 2 -CH 2} -C (CF 3) 2 -OH, -C terminated _{(CF 3) 2} -OH groups may be introduced. In this way, the copolymer in which the hydroxyalkyl group in which a part of the hydrogen atom of the alkyl group is replaced with the fluorine atom is introduced can reduce development defects and LER (line edge roughness: non-uniform unevenness of the line side wall). It is effective in reducing the amount of water.

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

<(F) component>
The component (F) is a fluorine additive component that is degradable with respect to an alkaline developer.

-Component (F1) In the resist composition of the present embodiment, the component (F) contains a fluororesin component (F1) (component (F1)) having a structural unit (f1) containing a base dissociative group.
By using a resist composition containing the component (F1), the contrast between the exposed portion and the unexposed portion of the resist film can be further improved when the resist pattern is formed.
As the component (F1), a copolymer having a structural unit (f2) containing a lactone-containing cyclic group in addition to the structural unit (f1) is preferable.
As the component (F1), a copolymer having a structural unit (f3) derived from the (α-substituted) acrylic acid ester in addition to the structural unit (f1) is preferable.
Further, the component (F1) may have other structural units other than the structural unit (f1), the structural unit (f2), and the structural unit (f3).

<< Structural unit (f1) >>
The structural unit (f1) is a structural unit containing a base dissociative group.
In the present invention, the "base dissociative group" refers to an organic group that can be dissociated by the action of a base. Examples of the base include an alkaline developer generally used in the field of lithography. That is, the "base dissociative group" refers to a group that dissociates by the action of an alkaline developer (for example, 2.38% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution (23 ° C.)).
The base dissociative group is hydrolyzed and dissociated by the action of the alkaline developer. Therefore, in the resist pattern formation, the base dissociative group in the structural unit (f1) is dissociated and the hydrophilic group is formed at the same time, the hydrophilicity of the resist film surface is strengthened, and the solubility of the resist film unexposed portion in the alkaline developer is increased. Is enhanced. Along with this, the contrast between the exposed portion and the unexposed portion of the resist film is improved.

Specific examples of the base dissociative group include groups represented by the following general formulas (II-1) to (II-5), respectively.
The base dissociative group in the structural unit (f1) is preferably at least one selected from the group consisting of the groups represented by the following general formulas (II-1) to (II-5), and is hydrophilic during alkaline development. The groups represented by the following general formulas (II-1), (II-4), and (II-5) are particularly preferable because they have excellent properties and are easy to synthesize.

［式中、Ｒ^０は、それぞれ独立して、フッ素原子を有していてもよい有機基である。］

[In the formula, R ⁰ is an organic group that may independently have a fluorine atom. ]

In the above formulas (II-1) to (II-5), R ⁰ is an organic group which may have a fluorine atom.
An "organic group" is a group containing at least one carbon atom.
The structure of R ⁰ may be linear, branched or cyclic, and is preferably linear or branched.
In R ⁰ , the organic group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and most preferably 1 to 5 carbon atoms.
R ⁰ preferably has a fluorination rate of 25% or more, more preferably 50% or more, and particularly preferably 60% or more.
The "fluorination rate" is the ratio (%) of (the number of fluorine atoms) to (the total number of hydrogen atoms and fluorine atoms) in the organic group.

As ^R0 , for example, a fluorinated hydrocarbon group which may have a methyl group, an ethyl group and a substituent is preferable.

Regarding the fluorinated hydrocarbon group which may have a substituent in R ⁰ , this hydrocarbon group may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a fat. It is preferably a group hydrocarbon group.
Aliphatic hydrocarbon groups are hydrocarbon groups that do not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferably saturated.
That is, R ⁰ is preferably a fluorinated saturated hydrocarbon group or a fluorinated unsaturated hydrocarbon group, and particularly preferably a fluorinated saturated hydrocarbon group, that is, a fluorinated alkyl group.
Examples of the fluorinated alkyl group include groups in which some or all of the hydrogen atoms of the unsubstituted alkyl groups listed below are substituted with fluorine atoms. The fluorinated alkyl group may be a group in which a part of the hydrogen atom of the unsubstituted alkyl group is substituted with a fluorine atom, or a group in which all the hydrogen atoms of the unsubstituted alkyl group are substituted with a fluorine atom ( Perfluoroalkyl group).

The unsubstituted alkyl group may be linear, branched or cyclic, or may be a combination of a linear or branched alkyl group and a cyclic alkyl group.
The unsubstituted linear alkyl group preferably has 1 to 10 carbon atoms, and more preferably 1 to 8 carbon atoms. Specifically, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n- A decyl group and the like can be mentioned.
The unsubstituted branched chain alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 8 carbon atoms. Among them, as the branched-chain alkyl group, a tertiary alkyl group is preferable.
As the unsubstituted cyclic alkyl group, for example, a group obtained by removing one hydrogen atom from a monocycloalkane; one hydrogen atom was removed from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane. The group is mentioned. Specific examples thereof include monocycloalkyl groups such as cyclopentyl group and cyclohexyl group; polycycloalkyl groups such as adamantyl group, norbornyl group, isobornyl group, tricyclodecyl group and tetracyclododecyl group.
As a combination of a linear or branched alkyl group and a cyclic alkyl group, a group in which a cyclic alkyl group is bonded as a substituent to a linear or branched alkyl group; a cyclic alkyl group. Examples of the substituent include a group to which a linear or branched alkyl group is bonded.

Examples of the substituent that the fluorinated hydrocarbon group may have include an alkyl group having 1 to 5 carbon atoms and the like.

In ^R0 , as the fluorinated alkyl group, a linear or branched alkyl fluorinated group is preferable. In particular, the group represented by the following general formula (III-1) or (III-2) is preferable, and among them, the group represented by the formula (III-1) is more preferable.

［式（ＩＩＩ−１）中、Ｒ^４１’は、無置換の炭素数１〜９のアルキレン基である。Ｒ^４２’は、炭素数１〜９のフッ素化アルキル基である。但し、Ｒ^４１’とＲ^４２’との炭素数の合計は１０以下である。式（ＩＩＩ−２）中、Ｒ^７４〜Ｒ^７６は、それぞれ独立に、炭素数１〜５の直鎖状のアルキル基であり、Ｒ^７４〜Ｒ^７６の少なくとも１つはフッ素原子を有するアルキル基である。］

Wherein ^{(III-1), R 41} ' is an unsubstituted alkylene group having 1 to 9 carbon atoms. R ⁴² 'is a fluorinated alkyl group having 1 to 9 carbon atoms. ^However, the total number of carbon atoms of ^{'R 42} and' ^{R 41} is 10 or less. In formula (III-2), R ^{74 to} R ⁷⁶ are independently linear alkyl groups having 1 to 5 carbon atoms, and ^{at least one of R 74 to} R ⁷⁶ is an alkyl group having a fluorine atom. Is. ]

Wherein (III-1), the alkylene group of R ^{41 'is} a straight-chain, branched-chain, it may be any of circular, linear or branched is preferred. Further, the carbon number thereof is preferably 1 to 5.
As R ⁴¹ ', a methylene group, an ethylene group and a propylene group are particularly preferable.
As R ⁴² ', a linear or branched alkyl fluorinated group having 1 to 5 carbon atoms is preferable. For example, a trifluoromethyl group (-CF ₃ ), a tetrafluoroethyl group (-C ₂ F ₄ H), and -C ₂ F ₅ are preferably mentioned.
In the formula (III-2), ^{as the alkyl group of R 74 to} R ⁷⁶ , a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. Any one of the alkyl groups of R ^{74 to} R ⁷⁶ may be a fluorinated alkyl group, and all of them may be fluorinated alkyl groups.

The component (F1) preferably has a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2) as the structural unit (f1).

［式中、Ｒは、それぞれ独立に、水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｘは、酸解離性部位を有さない２価の連結基である。Ａ_ａｒｙｌは、置換基を有していてもよい２価の芳香族環式基である。Ｘ_０１は、単結合又は２価の連結基である。Ｒ^２は、それぞれ独立に、フッ素原子を有する有機基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms, respectively. X is a divalent linking group that does not have an acid dissociative site. _Aryl is a divalent aromatic cyclic group that may have a substituent. X ₀₁ is a single bond or divalent linking group. R ² is an organic group each independently having a fluorine atom. ]

In the formulas (f1-1) and (f1-2), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, or n-. Examples thereof include a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
The alkyl halide group having 1 to 5 carbon atoms in R is a group in which a 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, an iodine atom and the like, and a fluorine atom is particularly preferable.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is more preferable from the viewpoint of industrial availability, and a methyl group is preferable. More preferred.

In the formula (f1-1), X is a divalent linking group having no acid dissociable site.
The "acid dissociative site" refers to a site in the organic group where an acid generated by exposure acts to dissociate.
Examples of the divalent linking group having no acid dissociable site of X include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a heteroatom.

Hydrocarbon groups that may have substituents X means that the hydrocarbon group "has a substituent" means that some or all of the hydrogen atoms in the hydrocarbon group are groups or atoms other than hydrogen atoms. It means that it is replaced with.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Aliphatic hydrocarbon groups mean hydrocarbon groups that do not have aromaticity. Such aliphatic hydrocarbon groups may be saturated or unsaturated, and are usually preferably saturated.

More specific examples of the aliphatic hydrocarbon group include a linear or branched-chain aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure, and the like.

... Linear or branched aliphatic hydrocarbon group The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, and more preferably 1 to 8 carbon atoms. Preferably, the number of carbon atoms is more preferably 1 to 5, and the number of carbon atoms 1 to 3 is particularly preferable.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group, an ethylene group [-(CH ₂ ) ₂ −], and a trimethylene group [-(CH _{2 ) 3} ). -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, and -C (CH ₃ ). Alkylene methylene groups such as _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) _{2-, etc.;-} CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )-, -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH ₃ ) CH _2- , -CH (CH ₂₎ CH ₃ ) Alkylethylene _{groups such as CH 2-} ; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH _2- and other alkyl methylene groups; -CH (CH ₃ ) CH ₂ Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ − and −CH ₂ CH (CH ₃ ) CH ₂ CH _{2 −.} As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.
The chain-like (linear, branched-chain) aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

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

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

Among the above, as the hydrocarbon group which may have a substituent, a linear, branched or cyclic aliphatic hydrocarbon group or a divalent aromatic hydrocarbon group is more preferable, and a methylene group is preferable. , Ethylene group, -CH (CH ₃ )-, a group obtained by removing one more hydrogen atom from a tetracyclododecanyl group, and an aromatic hydrocarbon group obtained by removing one more hydrogen atom from a phenyl group are particularly preferable. Of these, a methylene group, an ethylene group, and −CH (CH ₃ ) − are most preferable.

A divalent linking group including a hetero atom The hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
Examples of the divalent linking group containing a heteroatom include -O-, -C (= O)-, -C (= O) -O-, -OC (= O)-, and carbonate bond (-O-). OC (= O) -O-), -NH-, -NR ⁰⁴ (R ⁰⁴ is an alkyl group)-, -NH-C (= O)-, = N-, or "these groups" and 2 Examples include a combination with a valent hydrocarbon group.
Examples of the divalent hydrocarbon group here include the same hydrocarbon groups as those which may have the above-mentioned substituents, and linear or branched aliphatic hydrocarbon groups are preferable.
Among them, as the divalent linking group containing a hetero atom, a combination of the above-mentioned "these groups" and the divalent hydrocarbon group is more preferable, and more specifically, the above-mentioned "these groups" and the above-mentioned aliphatic group. A combination with a hydrocarbon group, a combination of the aliphatic hydrocarbon group, the "these groups" and the aliphatic hydrocarbon group is particularly preferable.

Among the above, X is preferably a divalent hydrocarbon group which may have a substituent, and more preferably a linear, branched chain or cyclic aliphatic hydrocarbon group.

In the general formula _{(f1-2), A aryl} is an aromatic cyclic group which may have a substituent. _{Specific examples of Aryl} include a group obtained by removing two hydrogen atoms from an aromatic hydrocarbon ring which may have a substituent.
The ring skeleton of the aromatic cyclic group for A _aryl, preferably has a carbon number of 6 to 15, for example, a benzene ring, a naphthalene ring, a phenanthrene ring, anthracene ring and the like. Among these, a benzene ring or a naphthalene ring is particularly preferable.
In _Aryl , examples of the substituent that the aromatic cyclic group may have include a halogen atom, an alkyl group, an alkoxy group, an alkyl halide group having 1 to 5 carbon atoms, an oxygen atom (= O) and the like. Can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom and a bromine atom. The _{substituent that the aromatic cyclic group of Aryl} may have is preferably a fluorine atom.
_{The aromatic cyclic group of Aryl} may have no substituent, may have a substituent, and preferably has no substituent.
In _Aryl , when the aromatic cyclic group has a substituent, the number of the substituents may be one, two or more, or one or two. Is preferable, and one is more preferable.

In the general formula (f1-2), X ⁰¹ is a single bond or a divalent linking group. The divalent linking group includes an alkylene group having 1 to 10 carbon atoms, -O-, -C (= O)-, -C (= O) -O-, -OC (= O)-, and carbonate. Examples thereof include a bond (-OC (= O) -O-), -NH-C (= O)-, or a combination thereof, and a combination of -O- and an alkylene group having 1 to 10 carbon atoms can be used. Most preferred.
Examples of the alkylene group having 1 to 10 carbon atoms include a linear, branched chain or cyclic alkylene group, and the linear or branched alkylene group having 1 to 5 carbon atoms and 4 to 10 carbon atoms. Cyclic alkylene groups are preferred.

In the formulas (f1-1) and (f1-2), R ² is an organic group having a fluorine atom.
The R ^2, wherein in the general formula (II-1) ~ (II -5) R 0 in good fluorinated hydrocarbon group optionally having a substituent and preferably, a fluorinated saturated hydrocarbon group (That is, a fluorinated alkyl group) is more preferable, a group represented by the above general formula (III-1) or (III-2) is further preferable, and among them, a group represented by the formula (III-1) is particularly preferable. ..

Among the structural units represented by the general formula (f1-1), the structural units represented by the following general formulas (f1-11) to (f1-15) are preferable.
Moreover, as a preferable one among the structural units represented by the general formula (f1-2), the structural units represented by the following general formulas (f1-21) to (f1-27) can be mentioned.

In the general formulas (f1-11) to (f1-14), (f1-21) to (f1-24), (f1-25) to (f1-27), R and R ² are the above-mentioned formulas (f1-21) to (f1-27), respectively. f1-1) and (f1-2) is the same as R and ^{R 2} in.
R ^{51 to} R ⁵² are independently alkyl groups having 1 to 10 carbon atoms.
R ^{53 to} R ⁵⁴ are independently hydrogen atoms or alkyl groups having 1 to 10 carbon atoms.
a1, a2, a3, a5, a7, a9, and a11 to a13 are independently integers of 1 to 5.
a4, a6, a8, and a10 are each independently an integer of 0 to 5.
a14 to a16 are independently integers of 0 to 5.
b1 to b5 are independently 0 or 1, respectively.
R ⁵ is a substituent.
e is an integer from 0 to 2.

In the formulas (f1-11) to (f1-14), (f1-21) to (f1-24), (f1-25) to (f1-27), R is preferably a hydrogen atom or a methyl group.

In the formula (f1-11), a1 is preferably an integer of 1 to 3, more preferably 1 or 2.
In the formula (f1-12), a2 and a3 are each independently preferably an integer of 1 to 3, and more preferably 1 or 2.

In the formula (f1-13), a4 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and most preferably 0 or 1.
a5 is preferably an integer of 1 to 3, more preferably 1 or 2.
Examples of the substituent of R ⁵ include a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkyl halide group having 1 to 5 carbon atoms, an oxygen atom (= O) and the like. Can be mentioned. Examples of the alkyl group having 1 to 5 carbon atoms include those similar to the alkyl group having 1 to 5 carbon atoms mentioned in R. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom and a bromine atom. Examples of the alkyl halide group having 1 to 5 carbon atoms include those similar to the alkyl halide group having 1 to 5 carbon atoms mentioned in R.
e is preferably 0 or 1, and is particularly preferably 0 in industry.
b2 is preferably 0.

In the formula (f1-14), a6 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and most preferably 0 or 1.
a7 is preferably an integer of 1 to 3, more preferably 1 or 2.
b3 is preferably 0.
R ⁵ and e are the same as defined above.

In the formula (f1-21), a8 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and most preferably 0 or 1.
a9 is preferably an integer of 1 to 3, more preferably 1 or 2.
b4 is preferably 0.
R ⁵ and e are the same as defined above.

In the formula (f1-22), a10 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and most preferably 0 or 1.
a11 is preferably an integer of 1 to 3, more preferably 1 or 2.
b5 is preferably 0.
R ⁵ and e are the same as defined above.

In the formula (f1-23), a12 is preferably an integer of 1 to 3, more preferably 1 or 2. R ⁵ and e are the same as defined above.
In the formula (f1-24), a13 is preferably an integer of 1 to 3, more preferably 1 or 2. R ⁵ and e are the same as defined above.

In formulas (f1-25) to (f1-27), a14, a15, and a16 are preferably 0 to 3, more preferably 0 to 2, and most preferably 0 or 1, respectively.
R ^{51 to} R ⁵² are preferably linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms, respectively, and have a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and the like. Examples include n-butyl group, isobutyl group, tert-butyl group, tert-amyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, norbornyl group, isobornyl group, tricyclodecanyl group, adamantyl group, tetracyclododecanyl group and the like. Of these, 1 to 6 carbon atoms are more preferable, 1 to 4 carbon atoms are particularly preferable, and a methyl group or an ethyl group is most preferable.
It is preferable that R ^{53 to} R ⁵⁴ are independently hydrogen atoms or linear, branched chain or cyclic alkyl groups having 1 to 10 carbon atoms. The linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms in ^{R 53 to} R ⁵⁴ are the same as those in ^{R 51 to} R ^52.
Wherein (f1-26) ~ (f1-27), R 5 and e are the same as defined above.

In the formula (f1-15), ^RC is a hydrogen atom or a methyl group.
Rf ^{1 to Rf 2} are independently hydrogen atoms, alkyl groups having 1 to 4 carbon atoms, or fluorinated alkyl groups having 1 to 4 carbon atoms.
The alkyl group having 1 to 4 carbon atoms in Rf ^{1 to Rf 2} may be linear, branched or cyclic, and is preferably a linear or branched alkyl group, specifically. , Methyl group and ethyl group are preferable, and ethyl group is particularly preferable.
The fluorinated alkyl group having 1 to 4 carbon atoms in Rf ^{1 to Rf 2} is a group in which a part or all of hydrogen atoms in the alkyl group having 1 to 4 carbon atoms are substituted with a fluorine atom. In the fluorinated alkyl group, the alkyl group in a state not substituted with a fluorine atom may be linear, branched or cyclic, and the above-mentioned "alkyl group having 1 to 4 carbon atoms in ^{Rf 1 to Rf 2" may be used.} The same thing can be mentioned.
Among the above, Rf ^{1 to Rf 2} are preferably hydrogen atoms or alkyl groups ^{having 1 to 4 carbon atoms, and one of Rf 1 to Rf 2} is a hydrogen atom and the other is an alkyl having 1 to 4 carbon atoms. It is particularly preferable that it is a group.

In the above formula (f1-15), Rf ³ is a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms.
Examples of the fluorinated alkyl group having 1 to 4 carbon atoms in Rf ^{3 include the same group as the above-mentioned "fluorinated alkyl group having 1 to 4 carbon atoms in Rf 1 to Rf 2} ", and the fluorinated alkyl group has 1 to 3 carbon atoms. Is preferable, and the number of carbon atoms is more preferably 1 to 2.
In ^{the fluorinated alkyl group of Rf 3} , the ratio (fluorination rate (%)) of (the number of fluorine atoms) to (the total number of fluorine atoms and hydrogen atoms) contained in the fluorinated alkyl group is 30 to. It is preferably 100%, more preferably 50 to 100%. The higher the fluorination rate, the higher the hydrophobicity of the resist film.

In the above formula (f1-15), Rf ⁴ is a linear or branched alkyl group having 1 to 4 carbon atoms or a linear fluorinated alkyl group having 1 to 4 carbon atoms and having 1 to 4 carbon atoms. It is preferably a linear alkyl group of 1 to 4 and a linear fluorinated alkyl group having 1 to 4 carbon atoms.
Specific examples of the alkyl group in Rf ⁴ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group and a tert-butyl group, and among them, a methyl group and an ethyl group are preferable. , Methyl group is most preferred.
Specific examples of the fluorinated alkyl group in Rf ⁴ _{include -CH 2-} CF ₃ , -CH _2- CF _2- CF ₃ , and -CH _2- CF _2- CF _2- CF _3. Of these, -CH _2- CF ₃ is the most preferable.

Specific examples of the structural units represented by the general formulas (f1-11) to (f1-15) and the general formulas (f1-21) to (f1-27) are shown below.

The structural unit (f1) is selected from the group consisting of the structural units represented by any of the general formulas (f1-11) to (f1-15) and (f1-21) to (f1-24). At least one is preferable, and a group consisting of structural units represented by any of the general formulas (f1-11) to (f1-13), (f1-15), (f1-21) and (f1-22). At least one selected from the above is more preferable, and at least one selected from the group consisting of the structural units represented by the general formulas (f1-11), (f1-15) and (f1-22) is particularly preferable. , The structural unit represented by the general formula (f1-11) is most preferable.

In the component (F1), one type of the constituent unit (f1) may be used alone, or two or more types may be used in combination.
The ratio of the constituent unit (f1) in the component (F1) is preferably 10 to 100 mol%, more preferably 30 to 90 mol%, based on the total (100 mol%) of all the constituent units constituting the (F1) component. It is preferable, and more preferably 55 to 85 mol%. When the ratio of the structural unit (f1) is equal to or higher than the lower limit of the above range, the hydrophilicity of the resist film surface is strengthened in the formation of the resist pattern, and the solubility of the resist film unexposed portion in the alkaline developer is likely to be enhanced. .. In addition, it is possible to reduce the occurrence of defects due to deposits and the like on the surface of the resist film. When the ratio of the structural unit (f1) is equal to or less than the upper limit of the above range, it becomes easy to balance with other structural units.

<< Structural unit (f2) >>
The component (F1) is preferably a copolymer having a structural unit (f2) containing a lactone-containing cyclic group in addition to the structural unit (f1) described above.
The lactone-containing cyclic group of the structural unit (f2) is effective in enhancing the adhesion of the resist film to the substrate when the component (F1) is used for forming the resist film. Further, by having the structural unit (f2), the solubility of the resist film in the alkaline developer is enhanced in the alkaline developing process.

The “lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing −OC (= O) − in its cyclic skeleton. The lactone ring is counted as the first ring, and when it has only a lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.

［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又はシアノ基である。Ｒ”は水素原子、アルキル基、ラクトン含有環式基、又は−ＳＯ_２−含有環式基である。Ａ”は酸素原子（−Ｏ−）もしくは硫黄原子（−Ｓ−）を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子である。ｎ’は０〜２の整数であり、ｍ’は０又は１である。］

Wherein, Ra ^'21 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, hydroxyl group, -COOR - in ", OC (= O) R ", a hydroxyalkyl group or a cyano group be. R "is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or a -SO ₂ -containing cyclic group. A" may contain an oxygen atom (-O-) or a sulfur atom (-S-). A good alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom. n'is an integer from 0 to 2, and m'is 0 or 1. ]

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

Ra '-COOR in ²¹ - in ", OC (= O) R ", R " are both hydrogen atom, an alkyl group, a lactone-containing cyclic group, or an -SO ₂ - containing cyclic group.
The alkyl group in "R" may be linear, branched or cyclic, and the number of carbon atoms is preferably 1 to 15.
When R "is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R "is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom. Alternatively, a group obtained by removing one or more hydrogen atoms from a monocycloalkane that may or may not be substituted with a fluorinated alkyl group; a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane. Examples thereof include a group obtained by removing one or more hydrogen atoms from the group. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane; Examples thereof include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as cyclodecane and tetracyclododecane.

Examples of the lactone-containing cyclic group in "R" include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7).

_{The "-SO 2} -containing cyclic group" in R "refers to a cyclic group containing a ring containing _{-SO 2- in} its ring skeleton, and specifically, a sulfur atom ( _{specifically, a sulfur atom in -SO 2-".} S) is a cyclic group forming a part of the cyclic skeleton of the cyclic group. _{A ring containing −SO 2} − in its ring skeleton is counted as the first ring, and if it is only the ring, it is a monocyclic group, and if it has another ring structure, it is a polycyclic group regardless of its structure. It is called. The −SO ₂ − containing cyclic group may be a monocyclic group or a polycyclic group.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton It is preferably a cyclic group containing a sultone ring to be formed. Specifically, the groups represented by the following general formulas (a5-r-1) to (a5-r-4) can be mentioned.

［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又はシアノ基である。Ｒ”は水素原子、アルキル基、ラクトン含有環式基、又は−ＳＯ_２−含有環式基である。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、酸素原子又は硫黄原子である。ｎ’は０〜２の整数である。］

Wherein, Ra ^'51 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, hydroxyl group, -COOR - in ", OC (= O) R ", a hydroxyalkyl group or a cyano group be. R "is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or a -SO ₂ -containing cyclic group. A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom. It is an oxygen atom or a sulfur atom. n'is an integer from 0 to 2. ]

In the general formulas (a5-r-1) to (a5-r-2), A "is a general formula (a2-r-2), (a2-r-3), (a2-r-5). It is the same as A "inside.
Alkyl group in ra ^'51, an alkoxy group, a halogen atom, a halogenated alkyl group, -COOR ", - OC (= O) R", The hydroxyalkyl group, each of the general formulas (a2-r-1) ~ ( a2-r-7) as in the same as those exemplified in the description of the Ra ^'21 of the like.

Ra 'The hydroxyalkyl group in the ^21, preferably has 1 to 6 carbon atoms, specifically, the Ra' at least one of the hydrogen atoms of the alkyl group include groups substituted with a hydroxyl group in the ²¹ ..

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

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

As the structural unit (f2), a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent is preferable.
The structural unit (f2) is preferably a structural unit represented by the following general formula (f2-1).

［式中、Ｒは、水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｙａ^２１は、単結合または２価の連結基である。Ｌａ^２１は−Ｏ−、−ＣＯＯ−、−ＣＯＮ（Ｒ’）−、−ＯＣＯ−、−ＣＯＮＨＣＯ−又は−ＣＯＮＨＣＳ−である。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。Ｒｆ^２１は、ラクトン含有環式基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms. Ya ²¹ is a single bond or divalent linking group. La ²¹ is -O-, -COO-, -CON (R')-, -OCO-, -CONHCO- or -CONHCS-. R'indicates a hydrogen atom or a methyl group. However, when La ²¹ is −O−, Ya ²¹ is not −CO−. Rf ²¹ is a lactone-containing cyclic group. ]

In the formula (f2-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, or n-. Examples thereof include a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The alkyl halide group having 1 to 5 carbon atoms in R is a group in which a 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, an iodine atom and the like, and a fluorine atom is particularly preferable. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is more preferable from the viewpoint of industrial availability, and a methyl group is preferable. More preferred.

In the formula (f2-1), Ya ²¹ is a single bond or a divalent linking group.
The ^{divalent linking group in Ya 21 is a divalent linking group in Ya x} 0 (a divalent hydrocarbon group which may have a substituent and a hetero atom, which have been described in the structural unit (a0) described above. The same as the divalent linking group including) can be mentioned. Among them, Ya ²¹ is a single bond, an ester bond [-C (= O) -O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof. Is preferable.

In the formula (f2-1), La ²¹ is -O-, -COO-, -CON (R')-, -OCO-, -CONHCO- or -CONHCS-. This R'indicates a hydrogen atom or a methyl group. However, when La ²¹ is −O−, Ya ²¹ is not −CO−.

In the formula (f2-1), Rf ²¹ is a lactone-containing cyclic group.
As ^{the lactone-containing cyclic group of Rf 21,} the groups represented by the above-mentioned general formulas (a2-r-1) to (a2-r-7) are preferably mentioned. Among them, the groups represented by the general formulas (a2-r-1), (a2-r-2) or (a2-r-6) are more preferable, and the groups represented by the general formula (a2-r-1) are represented. The groups to be formed are more preferable. Specifically, the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc2-1) to (r-lc-2-18) or (r- Any group represented by lc-6-1) is more preferable.

The structural unit (f2) contained in the component (F1) may be one type or two or more types.
When the component (F1) has a constituent unit (f2), the ratio of the constituent unit (f2) is 5 to 60 mol% with respect to the total (100 mol%) of all the constituent units constituting the component (F1). Preferably, 10 to 50 mol% is more preferable, and 15 to 45 mol% is further preferable.
When the ratio of the structural unit (f2) is not more than the lower limit of the above range, the solubility of the resist film in the alkaline developer is likely to be enhanced in the alkaline developing process. It is also effective in improving defects. When the ratio of the structural unit (f2) is equal to or less than the upper limit of the above range, it becomes easy to balance with other structural units.

≪Constructive unit (f3) ≫
The component (F1) is preferably a copolymer having a structural unit (f3) derived from the (α-substituted) acrylic acid ester in addition to the structural unit (f1) described above.
As a preferable structural unit (f3), for example, a structural unit represented by the following general formula (f3-1) can be mentioned.

［式中、Ｒは、水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide group having 1 to 5 carbon atoms. ]

In the general formula (f3-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, or n-. Examples thereof include a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The alkyl halide group having 1 to 5 carbon atoms in R is a group in which a 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, an iodine atom and the like, and a fluorine atom is particularly preferable. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is more preferable from the viewpoint of industrial availability, and a methyl group is preferable. More preferred.

The structural unit (f3) contained in the component (F1) may be one type or two or more types.
When the component (F1) has a constituent unit (f3), the ratio of the constituent unit (f3) is 5 to 60 mol% with respect to the total (100 mol%) of all the constituent units constituting the component (F1). Preferably, 10 to 50 mol% is more preferable, and 15 to 45 mol% is further preferable.
When the ratio of the structural unit (f3) is not more than the lower limit of the above range, the solubility of the resist film in the alkaline developer is likely to be enhanced in the alkaline developing process. In addition, the effect of suppressing the occurrence of defects is further improved. When the ratio of the structural unit (f3) is equal to or less than the upper limit of the above range, it is possible to balance with other structural units.

≪Other structural units≫
The component (F1) may have other structural units other than the structural unit (f1), the structural unit (f2), and the structural unit (f3).
The other structural units are not particularly limited as long as they are not classified into the above-mentioned structural units, and are used for resist resins for ArF excimer lasers, KrF excimer lasers (preferably for ArF excimer lasers), and the like. A large number of conventionally known ones can be used.

Structural unit (f4):
In addition to the structural unit (f1), the component (F1) may further have a structural unit (f4) derived from a (α-substituted) acrylic acid ester containing an acid-degradable group.

An "acid-degradable group" is a group having an acid-degradable property in which at least a part of the bonds in the structure of the acid-degradable group can be cleaved by the action of an acid.
Examples of the acid-degradable group whose polarity is increased by the action of an acid include a group which is decomposed by the action of an acid to produce a polar group.
Examples of the polar group, such as carboxy group, a hydroxyl group, an amino group, such as a sulfo group _(-SO 3 H) and the like. Among these, a polar group containing −OH in the structure (hereinafter, may be referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is more preferable, and a carboxy group is particularly preferable.
More specific examples of the acid-degradable group include a group in which the polar group is protected by an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).
Here, the "acid dissociative group" is (i) a group having an acid dissociative property in which the bond between the acid dissociative group and an atom adjacent to the acid dissociative group can be cleaved by the action of an acid. Alternatively, after a part of the bond is cleaved by the action of the acid (ii), a decarbonation reaction is further caused, so that the bond between the acid dissociative group and the atom adjacent to the acid dissociative group is cleaved. It refers to both the basis to obtain.
The acid dissociable group constituting the acid-degradable group needs to be a group having a lower polarity than the polar group produced by the dissociation of the acid-dissociable group, whereby the acid-dissociable group is affected by the action of the acid. When is dissociated, a polar group having a higher polarity than the acid dissociative group is generated and the polarity is increased. As a result, the polarity of the entire (F1) component increases. As the polarity increases, the solubility in the developer changes relatively, and when the developer is an alkaline developer, the solubility increases.

Preferred structural units (f4) include, for example, at least one structural unit selected from the group consisting of structural units represented by the following general formula (f4-1) or general formula (f4-2).

［式中、Ｒ^Ｃは、それぞれ独立して、水素原子又はメチル基である。Ｒ^ｆ４は、それぞれ独立して、炭素数１〜５のアルキル基である。ｈ”は、１〜４の整数である。］

[In the formula ^{, each RC} is a hydrogen atom or a methyl group independently. R ^f4 is an alkyl group having 1 to 5 carbon atoms independently. "h" is an integer of 1 to 4.]

In the formulas (f4-1) and (f4-2), R ^f4 is an alkyl group having 1 to 5 carbon atoms independently, and specifically, a methyl group, an ethyl group, a propyl group, and an isopropyl group. A linear or branched alkyl group such as a group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, or a neopentyl group is preferable, and is a methyl group or an ethyl group. Is more preferable.
In the formula (f4-1), h "is an integer of 1 to 4, preferably 1 or 2, and more preferably 1.

When the component (F1) has a constituent unit (f4), the ratio of the constituent unit (f4) is 5 to 50 mol% with respect to the total (100 mol%) of all the constituent units constituting the component (F1). Preferably, 5 to 40 mol% is more preferable, and 5 to 35 mol% is further preferable.
When the ratio of the structural unit (f4) is not more than the lower limit of the above range, the solubility in the developing solution in the resist film exposed portion can be further promoted. When the ratio of the structural unit (f4) is equal to or less than the upper limit of the above range, the balance with other structural units can be achieved.

In the resist composition of the present embodiment, the component (F) contains the polymer compounds (F1) (component (F1)) having the structural unit (f1).
Preferred (F1) components include a polymer (homopolymer) composed of the structural unit (f1), a copolymer having a repeating structure of the structural unit (f1) and the structural unit (f2), and the structural unit (f1). Examples thereof include a copolymer having a repeating structure with the unit (f3) and a copolymer having a repeating structure of the structural unit (f1), the structural unit (f2) and the structural unit (f3).

The component (F1) is obtained by polymerizing a monomer for inducing a desired constituent unit by, for example, a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate. Can be obtained by

The weight average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography) of the component (F1) is preferably 1000 to 50000, more preferably 5000 to 40,000, and even more preferably 1000 to 30000. When it is not more than the upper limit value of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is more than the lower limit value of this range, the dry etching resistance and the cross-sectional shape of the resist pattern are good.

The dispersity (Mw / Mn) of the component (F1) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and even more preferably 1.2 to 2.5.

In the resist composition of the present embodiment, one type of the component (F1) may be used alone, or two or more types may be used in combination.
In the resist composition of the present embodiment, as the component (F), a fluorine additive component that does not correspond to the component (F1) and exhibits degradability to an alkaline developer may be used in combination.
The ratio of the component (F1) to the component (F) is preferably 25% by mass or more, more preferably 50% by mass or more, further preferably 75% by mass or more, and 100% by mass with respect to the total mass of the component (F). It may be. When the ratio of the component (F1) is 25% by mass or more, it becomes easier to improve the contrast between the exposed portion and the unexposed portion of the resist film when forming the resist pattern.

In the resist composition of the present embodiment, the component (F) may be used alone or in combination of two or more.
In the resist composition of the present embodiment, the content of the component (F) 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). 1 to 5 parts by mass is more preferable.
When the content of the component (F) is not more than the lower limit of the above range, the solubility of the unexposed portion of the resist film in the alkaline developer is likely to be enhanced in the resist pattern formation, and the resolution performance is further improved. In addition, the occurrence of defects is suppressed. On the other hand, when it is not more than the upper limit value, the lithography characteristics are further improved.

<Arbitrary ingredient>
The resist composition of the present embodiment may further contain a component (arbitrary component) other than the above-mentioned component (A) and component (F).
Examples of such an optional component include the following components (B), (D), (C), (E), and (S).

≪ (B) component ≫
The resist composition of the present embodiment may further contain an acid generator component (hereinafter referred to as "component (B)") in addition to the component (A) and the component (F).
The component (B) is not particularly limited, and those previously proposed as an acid generator for a chemically amplified resist can be used.
Examples of such an acid generator include onium salt-based acid generators such as iodonium salt and sulfonium salt, and oxime sulfonate-based acid generators; diazomethanes such as bisalkyl or bisarylsulfonyldiazomethanes and poly (bissulfonyl) diazomethanes. Acid generators: Various types such as nitrobenzyl sulfonate-based acid generators, imino sulfonate-based acid generators, and disulfon-based acid generators can be mentioned. Of these, it is preferable to use an onium salt-based acid generator.

Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter, also referred to as “component (b-1)”) 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、又は置換基を有していてもよい鎖状のアルケニル基である。Ｒ^１０４、Ｒ^１０５は、相互に結合して環を形成していてもよい。Ｒ^１０２はフッ素原子又は炭素数１〜５のフッ素化アルキル基である。Ｙ^１０１は単結合又は酸素原子を含む２価の連結基である。Ｖ^１０１〜Ｖ^１０３はそれぞれ独立に単結合、アルキレン基又はフッ素化アルキレン基である。Ｌ^１０１〜Ｌ^１０２はそれぞれ独立に単結合又は酸素原子である。Ｌ^１０３〜Ｌ^１０５はそれぞれ独立に単結合、−ＣＯ−又は−ＳＯ_２−である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

[In the formula, R ¹⁰¹ and R ^{104 to} R ¹⁰⁸ each have a cyclic group which may independently have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group that may be present. R ¹⁰⁴ and R ¹⁰⁵ may be coupled 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 independently single-bonded, alkylene groups or fluorinated alkylene groups, respectively. L ^{101 to} L ¹⁰² are independently single bonds or oxygen atoms, respectively. L ¹⁰³ ~L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ - is. m is an integer of 1 or more, ^{and M'm +} is an m-valent onium cation. ]

{Anion part}
In the anion part formula (b-1) of the component (b-1), R ¹⁰¹ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, and the like. Alternatively, it is 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 aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

The aromatic hydrocarbon group in R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, further preferably 5 to 20 carbon atoms, and particularly preferably 6 to 15 carbon atoms. The numbers 6 to 10 are most preferable. However, the number of carbon atoms does not include the number of carbon atoms in the substituent.
^{Specifically, as the aromatic ring contained} in the aromatic hydrocarbon group in R 101, benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a part of carbon atoms constituting these aromatic rings was substituted with a hetero atom. Examples include aromatic heterocycles. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like.
Specifically, the aromatic hydrocarbon group in R ¹⁰¹ is a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and one of the hydrogen atoms in the aromatic ring is an alkylene group. Examples thereof include a group substituted with (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group) 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.

Examples of the cyclic aliphatic hydrocarbon group in R ¹⁰¹ include an aliphatic hydrocarbon group containing a ring in the structure.
As the aliphatic hydrocarbon group containing a ring in this structure, an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from the aliphatic hydrocarbon ring) and an alicyclic hydrocarbon group are linear or branched. Examples thereof include a group bonded to the terminal of a chain-shaped aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among them, the polycycloalkane is a polycycloalkane having a polycyclic skeleton of a crosslinked ring system such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; a fused ring system such as a cyclic group having a steroid skeleton. Polycycloalkanes having a polycyclic skeleton of are more preferred.

Among them, as ^{the cyclic aliphatic hydrocarbon group in R 101} , a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane is preferable, and a group obtained by removing one hydrogen atom from polycycloalkane is more preferable. Preferably, an adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and carbon. Numbers 1 to 4 are more preferable, and carbon numbers 1 to 3 are most preferable.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [−CH ₂ −], an ethylene group [− (CH ₂ ) ₂ −], and 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 preferable, and specifically, -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, and -C (CH ₃ ). Alkylene methylene groups such as _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) _{2-, etc.;-} 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) Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ − and −CH ₂ CH (CH ₃ ) CH ₂ CH _{2 −.} As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

Further, ^{the cyclic hydrocarbon group in R 101} may contain a hetero atom such as a heterocycle. Specific examples of the cyclic hydrocarbon group in R ¹⁰¹ include a lactone-containing cyclic group represented by the above general formulas (a2-r-1) to (a2-r-7), respectively, and the above general formula (a5-r-7). _{-SO 2} -containing cyclic groups represented by r-1) to (a5-r-4), respectively, and other represented by the following chemical formulas (r-hr-1) to (r-hr-16), respectively. Heterocyclic groups can be mentioned.

Further, as a cyclic group which may have a substituent, an acid dissociable group can also be mentioned.

Examples of the substituent in the cyclic group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group, a carbonyl group, a nitro group and the like.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are more preferable.
As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferable, and methoxy. Groups and ethoxy groups are most preferable.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.
As the alkyl halide 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, and a tert-butyl group are described above. Examples include groups substituted with halogen atoms.
The carbonyl group as a substituent is a group that substitutes the _{methylene group (−CH 2−) constituting the cyclic hydrocarbon group.}

Chain-like alkyl group which may have a substituent:
The chain alkyl group of 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, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decanyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group and a tetradecyl group. Examples thereof include a group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecil group, an icosyl group, a henicosyl group, a docosyl group and the like.
The branched-chain 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 thereof include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group and 4-methylpentyl group.
Moreover, as a chain alkyl group which may have a substituent, an acid dissociative group is also mentioned.

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

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

Among the above, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, one or more hydrogen atoms from a phenyl group which may have a substituent, a naphthyl group which may have a substituent, and a polycycloalkane which may have a substituent. Excluded groups; lactone-containing cyclic groups represented by the general formulas (a2-r-1) and (a2-r-3) to (a2-r-7), respectively; the general formula (a5-r-1). )-(A5-r-4), respectively, -SO ₂ -containing cyclic groups and the like are preferable.

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

In the formula (b-1), Y ¹⁰¹ is a divalent linking group or a single bond containing an oxygen atom.
The ^{divalent linking group in Y 101} may contain an atom other than the oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms and the like.
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 (−OC (= O−). )-), Amid bond (-C (= O) -NH-), carbonyl group (-C (= O)-), carbonate bond (-OC (= O) -O-) and other non-carbohydrates Oxygen atom-containing linking group of the system; Examples thereof include a combination of the oxygen atom-containing linking group of the non-hydrogen system and an alkylene group. A sulfonyl group (-SO _2- ) may be further linked to this combination.
Examples of the divalent linking group containing such an oxygen atom include linking groups represented by the following general formulas (y-al-1) to (y-al-7), respectively.

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

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

Divalent saturated hydrocarbon group in V ^'102 is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, alkylene group having 1 to 5 carbon atoms Is more preferable.

The alkylene group for V ^'101 and V' ^102, respectively, may be linear well branched alkylene group with an alkylene group, a linear alkylene group is preferable.
As the alkylene group for V ^'101 and V' ^102, specifically, a methylene group _{[-CH 2 -]; - CH} (CH 3) -, - CH (CH 2 CH 3) -, - C (CH 3) Alkylene methylene groups such as _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) _{2-, etc.; ethylene} Group [-CH ₂ CH _2- ]; -CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )-, -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH) ₃ ) _{Alkylethylene groups such as CH 2-} ; trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH _2- ]; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) Alkyl methylene groups such as CH _{2- ; tetramethylene groups [-CH 2} CH ₂ CH ₂ CH _2- ]; -CH (CH ₃ ) CH ₂ CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ Alkyltetramethylene groups such as CH _2- ; pentamethylene groups [-CH ₂ CH ₂ CH ₂ CH ₂ CH _2- ] and the like can be mentioned.
A part of the methylene groups in the alkylene group for V ^'101 or V' ¹⁰² may be substituted by a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group obtained by removing one hydrogen atom from the cyclic aliphatic hydrocarbon group in ^{R 101, and is preferably a cyclohexylene group, a 1,5-adamantylene group or 2,} A 6-adamantylene group is more preferred.

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

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

Specific examples of the anion portion of the component (b-1) include fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anion and perfluorobutane sulfonate anion when ^{Y 101 is a single bond; Y 101} is In the case of a divalent linking group containing an oxygen atom, an anion represented by any of the following formulas (an-1) to (an-3) can be mentioned.

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

[In the formula, R " ¹⁰¹ is an aliphatic cyclic group which may have a substituent, a group represented by the above formulas (r-hr-1) to (r-hr-6), or a substituent, respectively. It is a chain alkyl group which may have a group; R " ¹⁰² is an aliphatic cyclic group which may have a substituent, the general formulas (a2-r-1) to (a2-). lactone-containing cyclic group represented respectively by r-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. V "is independently an integer of 0 to 3, q" is independently an integer of 1 to 20, t "is an integer of 1 to 3, and n" is 0 or 1. .]

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 those similar to those in which the cyclic aliphatic hydrocarbon group in R ^{101 may be substituted.}

The aromatic cyclic group which may have a substituent in R " ¹⁰³ is preferably a group exemplified as an aromatic hydrocarbon group in the cyclic hydrocarbon group in ^{R 101. The substituent is preferably a group.} , The same as the substituent which may replace the aromatic hydrocarbon group in ^{R 101.}

The chain-like alkyl group which may have a substituent at R " ¹⁰¹ is preferably a group exemplified as the chain-like alkyl group at ^{R 101. It} has a substituent at ^{R "103.} The good chain alkenyl group is preferably the group exemplified as the chain alkenyl group in ^{R 101.}

-In the anion part formula (b-2) of the component (b-2), R ¹⁰⁴ and R ¹⁰⁵ may independently have a substituent, even if they have a cyclic group and a substituent. Examples thereof include a good chain alkyl group and a chain alkenyl group which may have a substituent, respectively, which are similar to ^{R 101 in the formula (b-1).} However, R ¹⁰⁴ and R ¹⁰⁵ may be coupled to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably chain-like alkyl groups which may have a substituent, and are linear or branched-chain alkyl groups, or linear or branched-chain fluorinated alkyl groups. Is more preferable.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and further 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 because the solubility in the resist solvent is also good within the above carbon number range. Further, in ^{the chain alkyl groups of R 104} and R ^105, the larger the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and the stronger the acid strength, and the higher the acid strength against high-energy light and electron beams of 200 nm or less. This is preferable because it improves transparency. The ratio of fluorine atoms in the chain alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. It is a perfluoroalkyl group.

In formula (b-2), V ¹⁰² and V ¹⁰³ are independently single-bonded, alkylene groups, or fluorinated alkylene groups, respectively, which are similar to ^{V 101 in formula (b-1).} Can be mentioned.
In formula (b-2), L ¹⁰¹ and L ¹⁰² are independently single bonds or oxygen atoms, respectively.

-In the anion part formula (b-3) of the component (b-3), R ^{106 to} R ¹⁰⁸ may independently have a substituent, even if they have a cyclic group or a substituent. Examples thereof include a good chain alkyl group and a chain alkenyl group which may have a substituent, respectively, which are similar to ^{R 101 in the formula (b-1).}
L ^{103 to} L ¹⁰⁵ are each independently single-bonded, -CO- or -SO _2- .

Among the above, the component (b-1) is preferable as the component (B).
As the anion portion of the component (b-1), an anion represented by either the above general formula (an-1) or (an-2) is more preferable, and it is represented by the general formula (an-2). Anions are particularly preferred.

Specific examples of the preferred anion portion of the component (B) include anions represented by the following formulas (an-1-1) to (an-1-3) or (an-2-1).

・ ・ Cation part (( ^{M'm +} ) _{1 / m} )
In the above formula (b-1) ^{, M'm +} is an m-valent onium cation. m is an integer greater than or equal to 1.
As ^{the M'm +} onium cation, a sulfonium cation and an iodonium cation are preferable.
Preferred cation portions (( ^{M'm +} ) _{1 / m} ) include organic cations represented by the following general formulas (ca-1) to (ca-5), respectively.

［式中、Ｒ^２０１〜Ｒ^２０７、およびＲ^２１１〜Ｒ^２１２は、それぞれ独立に置換基を有していてもよいアリール基、置換基を有していてもよいアルキル基または置換基を有していてもよいアルケニル基を表す。Ｒ^２０１〜Ｒ^２０３、Ｒ^２０６〜Ｒ^２０７、Ｒ^２１１〜Ｒ^２１２は、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のアルキル基を表す。Ｒ^２１０は、置換基を有していてもよいアリール基、置換基を有していてもよいアルキル基、置換基を有していてもよいアルケニル基、又は置換基を有していてもよい−ＳＯ_２−含有環式基である。Ｌ^２０１は、−Ｃ（＝Ｏ）−または−Ｃ（＝Ｏ）−Ｏ−を表す。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す。ｘは１または２である。Ｗ^２０１は（ｘ＋１）価の連結基を表す。Ｗ^ｂは、置換基を有していてもよい炭化水素基である。Ｒ^ｓ１〜Ｒ^ｓ４は、それぞれ独立に、置換基である。ｎ_ｂ１〜ｎ_ｂ４は、それぞれ独立に、０〜３の整数である。］

[In the formula, R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² each have an aryl group that may independently have a substituent, an alkyl group that may have a substituent, or a substituent. Represents an alkenyl group that may be present. 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 independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 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. L ²⁰¹ represents −C (= O) − or −C (= O) −O−. Y ²⁰¹ independently represents an arylene group, an alkylene group or an alkaneylene group. x is 1 or 2. W ²⁰¹ represents a linking group of (x + 1) valence. W ^b is a hydrocarbon group which may have a substituent. R ^{s1 to} R ^s4 are independent substituents. n _{b1 to} n _b4 are independently integers of 0 to 3. ]

In the above formulas (ca-1) to (ca-4), ^{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 phenyl. A group and a naphthyl group are preferable.
The alkyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² preferably has 2 to 10 carbon atoms.
Substituents that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have include, for example, an alkyl group, a halogen atom, an alkyl halide group, a carbonyl group, a cyano group, an amino group, an aryl group, and the following. Examples thereof include groups represented by the general formulas (ca-r-1) to (ca-r-7) of.

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

Wherein the R ^'201 independently, a hydrogen atom, have may have a substituent group cyclic group which may have a substituent chain alkyl group, or a substituent It is a chain alkenyl group which may be used. ]

R ^'201 substituents cyclic group which may have a substituent and has optionally also good chain alkyl group, or have a substituent which may chain alkenyl groups, above ^{In addition to the same as R 101 in} the formula (b-1) of the above, as a cyclic group which may have a substituent or a chain alkyl group which may have a substituent, an acid Dissociative groups are also mentioned.

When R ^{201 to} R ²⁰³ , R ^{206 to} R ²⁰⁷ , and R ^{211 to} R ²¹² are bonded to each other to form a ring together with the sulfur atom in the formula, heteroatoms such as sulfur atom, oxygen atom, and nitrogen atom, and heteroatoms such as sulfur atom and nitrogen atom, and 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. It may be bonded via a functional group of. As the ring to be formed, one ring containing a sulfur atom in its ring skeleton, including the sulfur atom, is preferably a 3 to 10-membered ring, and particularly preferably a 5- to 7-membered ring. preferable. Specific examples of the ring to be formed include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxatiin ring, and a tetrahydro. Examples thereof include a thiophenium ring and a tetrahydrothiopyranium ring.

R ^{208 to} R ²⁰⁹ independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferable, and when they are alkyl groups, they are bonded to each other. 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.
^Examples of the aryl group in R 210 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 ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group in R ²¹⁰ preferably has 2 to 10 carbon atoms.
Table is preferably the general formula (a5-r-1) The content cyclic group, - at R ^210, which may have -SO ₂ substituents "- containing polycyclic group - SO _2" Is more preferred.

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

In the formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x + 1) valence, i.e., a divalent or trivalent linking group.
As the ^{divalent linking group in W 201, a} divalent hydrocarbon group which may have a substituent is preferable, and a divalent hydrocarbon which may have a substituent similar ^{to Ya x0 described above is preferable.} A hydrogen group can be exemplified. 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. As the ^{trivalent linking group in W 201} , a group in which two carbonyl groups are bonded to an arylene group is preferable.

In the formula (ca-5), W ^b is a hydrocarbon group which may have a substituent.
The hydrocarbon group in W ^b may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

· Divalent aliphatic hydrocarbon group as the hydrocarbon group in the aliphatic hydrocarbon radical W ^b may be saturated, may be unsaturated, but is preferably saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure, and the like.

Linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and 1 to 4 carbon atoms. More preferably, 1 to 3 are most preferable.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [−CH ₂ −], an ethylene group [− (CH ₂ ) ₂ −], and a trimethylene group [ − (CH ₂ ) ₃ −], tetramethylene group [− (CH ₂ ) ₄ −], pentamethylene group [− (CH ₂ ) ₅ −] and the like can be mentioned.
The branched-chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, and -C (CH ₃ ). Alkylene methylene groups such as _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) _{2-, etc.;-} 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) Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ − and −CH ₂ CH (CH ₃ ) CH ₂ CH _{2 −.} As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

An aliphatic hydrocarbon group containing a ring in the structure The aliphatic hydrocarbon group containing a ring in the structure is an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring). , A group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, an alicyclic hydrocarbon group in the middle of a linear or branched aliphatic hydrocarbon group Examples include groups intervening in. Examples of the linear or branched aliphatic hydrocarbon group include the same groups as described above.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic type or a monocyclic type. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples 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 is preferably a polycycloalkane having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

-Aromatic hydrocarbon group An aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
Aromatic hydrocarbon group as the divalent hydrocarbon group for ^{W b} is preferably 3 to 30 carbon atoms, more preferably from 5 to 30 carbon atoms, 5 to 20 carbon atoms more preferably from 6 carbon atoms 15 is particularly preferable, and 6 to 10 carbon atoms are most preferable. However, the number of carbon atoms does not include the number of carbon atoms in the substituent.
Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; some of the carbon atoms constituting the aromatic hydrocarbon ring are hetero. Aromatic heterocycles substituted with atoms; etc. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like.
Specifically, as the aromatic hydrocarbon group, a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group, preferably a phenylene group or a naphthylene group); a hydrogen atom from the aromatic hydrocarbon ring. A group in which one of the hydrogen atoms of the removed group (aryl group) is substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, 2 -A group obtained by removing one more hydrogen atom from an aryl group in an arylalkyl group such as a 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.

Substituents that the hydrocarbon group of W ^b may have include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an oxo group (= O), a hydroxyl group (-OH), and an amino group. (-NH ₂ ) and the like can be mentioned.

Among them, as W ^b , an aromatic hydrocarbon group is preferable, and as an aromatic ring contained in the aromatic hydrocarbon group, benzene, biphenyl or naphthalene is preferable, and benzene and biphenyl are more preferable.

In the above formula (ca-5), R ^{s1 to} R ^s4 are independent substituents.
Examples of the substituents of R ^{s1 to} R ^s4 include an alkyl group, a halogen atom, an alkyl halide group, a carbonyl group, a cyano group, an amino group, an aryl group and an arylthio group, and the above general formula (ca-r-1). )-(Ca-r-7), respectively.
Examples of the arylthio group as a substituent include a phenylthio group or a biphenylthio group.

In the above formula (ca-5), n _{b1 to} n _b4 are independently integers of 0 to 3, preferably 0 or 1, and more preferably 0.

Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-75).

［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。］

[In the formula, g1, g2, and g3 indicate 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、該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。］

[In the formula, R " ²⁰¹ is a hydrogen atom or a substituent, and the substituents are the same as those listed as the substituents that ^{R 201 to} R ²⁰⁷ and R ^{210 to} R ^{212 may have.} Is.]

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

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

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

Specific examples of suitable cations represented by the formula (ca-5) include cations represented by the following formulas (ca-5-1) to (ca-5-2).

Among the above, the cation portion (( ^{M'm +} ) _{1 / m} ) of the component (B) is preferably a cation represented by the general formula (ca-1). Among these, an onium cation represented by the following general formula (b-ca-1) is particularly preferable.

［式中、Ｒ^ｂ１１は、置換基としてフッ素化アルキル基もしくはフッ素原子を有するアリール基、置換基としてフッ素化アルキル基もしくはフッ素原子を有するアルキル基、又は置換基としてフッ素化アルキル基もしくはフッ素原子を有するアルケニル基を表す。Ｒ^ｂ１２及びＲ^ｂ１３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、置換基を有していてもよいアルキル基、又は置換基を有していてもよいアルケニル基を表す。Ｒ^ｂ１１〜Ｒ^ｂ１３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。］

[In the formula, R ^b11 has an aryl group having a fluorinated alkyl group or a fluorine atom as a substituent, an alkyl group having a fluorinated alkyl group or a fluorine atom as a substituent, or a fluorinated alkyl group or a fluorine atom as a substituent. Represents an alkenyl group having. R ^b12 and R ^b13 independently represent an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. R ^{b11 to} R ^b13 may be bonded to each other to form a ring together with the sulfur atom in the formula. ]

In the above formula (b-ca-1), R ^b11 is an aryl group having a fluorinated alkyl group or a fluorine atom as a substituent, an alkyl group having a fluorinated alkyl group or a fluorine atom as a substituent, or fluorine as a substituent. Represents an alkyl group or an alkenyl group having a fluorine atom.
R ^{b11 is the same as that in which the aryl group, alkyl group or alkenyl group in R 201} in the above formula (ca-1) has a fluorinated alkyl group or a fluorine atom as a substituent, respectively.

In the above formula (b-ca-1), R ^b12 and R ^b13 independently have an aryl group which may have a substituent, an alkyl group which may have a substituent, or a substituent. Represents an alkenyl group that may have. ^Examples of R b12 and R ^b13 are the same as those ^{of R 202} and R ^{203 in} the above formula (ca-1).

When R ^{b11 to} R ^b13 are bonded to each other to form a ring together with the sulfur atom in the formula, heteroatoms such as sulfur atom, oxygen atom and nitrogen atom, carbonyl group, -SO-, -SO ₂ -,- _{SO 3 -, - COO -,} - CONH- , or -N _(R N) - (wherein _{R N} is an alkyl group of 1 to 5 carbon atoms.) or may be bonded via a functional group such as. As the ring to be formed, one ring containing a sulfur atom in its ring skeleton, including the sulfur atom, is preferably a 3 to 10-membered ring, and particularly preferably a 5- to 7-membered ring. preferable.

Specific examples of the suitable component (B) are given below.

In the resist composition of the present embodiment, the component (B) may be used alone or in combination of two or more.
In the resist composition of the present embodiment, the content of the component (B) is preferably 1 to 40 parts by mass, more preferably 5 to 35 parts by mass with respect to 100 parts by mass of the component (A). It is preferably 9 to 30 parts by mass, and more preferably 9 to 30 parts by mass.
When the content of the component (B) is at least the above-mentioned preferable lower limit value, the lithography characteristics such as sensitivity, resolution performance, LWR (linewise roughness) reduction, and shape are further improved in resist pattern formation. On the other hand, when it is not more than the preferable upper limit value, when each component of the resist composition is dissolved in an organic solvent, a uniform solution can be easily obtained, and the storage stability of the resist composition is further enhanced.

≪ (D) component ≫
In the resist composition of the present embodiment, in addition to the components (A) and (F), an acid diffusion control agent component that controls the diffusion of acid generated by exposure in the resist composition (hereinafter, "component (D)"). It is preferable to contain.).

-Component (D1) The resist composition of the present embodiment preferably contains, as the component (D), a photodisintegrating base (D1) (component (D1)) that is decomposed by exposure and loses acid diffusion controllability. ..
By using a resist composition containing the component (D1), the contrast between the exposed portion and the unexposed portion of the resist film can be further improved when the resist pattern is formed.
The component (D1) is not particularly limited as long as it is an acid diffusion control agent component that is decomposed by exposure and loses acid diffusion controllability, and is a compound represented by the following general formula (d1-1) (hereinafter, "D1"). (D1-1) component "), a compound represented by the following general formula (d1-2) (hereinafter referred to as" (d1-2) component "), and represented by the following general formula (d1-3). One or more compounds selected from the group consisting of compounds (hereinafter referred to as "(d1-3) components") are preferable.
Each of the components (d1-1) to (d1-3) decomposes in the exposed portion of the resist film and loses acid diffusion controllability (basicity), so that it does not act as a quencher, and in the unexposed portion of the resist film. Acts as a quencher.

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

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

{(D1-1) component}
In the anion part formula (d1-1), Rd ¹ has a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. These are chain alkenyl groups which may be present, and examples thereof include the same ^{groups as R 101 in the above formula (b-1).}
Among these, Rd ¹ may have an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. A chain alkyl group is preferred.
Substituents that these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, alkyl fluorinated groups, and the above general formulas (a2-r-1) to (a2-r-). Examples thereof include a lactone-containing cyclic group represented by 7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, an alkylene group may be used as a substituent, and the substituent in this case is shown in the above formulas (y-al-1) to (y-al-5), respectively. The linking group to be used is preferable.
As the aromatic hydrocarbon group, a phenyl group or a naphthyl group is more preferable.
The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane.
The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically, 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 the like. Linear alkyl groups such as nonyl group and decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl Examples thereof include branched alkyl groups such as a group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

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

A preferable specific example of the anion portion of the component (d1-1) is shown below.

In the cation part equation (d1-1), M ^{m +} is an m-valent organic cation.
As ^{the organic cation of M m +,} the same cations as those represented by the general formulas (ca-1) to (ca-4) are preferably mentioned, and are represented by the general formula (ca-1). Cations are more preferable, and cations represented by the above formulas (ca-1-1) to (ca-1-75) are even more 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}
In the anion part formula (d1-2), Rd ² has a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group which may be present, and examples thereof include the same group as ^{R 101 in the above formula (b-1).}
However, it is assumed that the carbon atom adjacent to the S atom in ^{Rd 2 does not have a fluorine atom bonded (fluorine-substituted).} As a result, the anion of the component (d1-2) becomes an appropriate weak acid anion, and the citric acid ability as the component (D) is improved.
Rd ² is preferably a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. As the aliphatic cyclic group, a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (may have a substituent); one from camphor, etc. It is more preferable that the group is a group excluding the above hydrogen atom.
The hydrocarbon group of Rd ² may have a substituent, and the substituent may be a hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group ^{) in Rd 1 of the above formula (d1-1).} , The same as the substituent which the chain alkyl group) may have.

A preferable specific example of the anion portion of the component (d1-2) is shown below.

In the cation part formula (d1-2), M ^{m +} is an m-valent organic cation, which is the same as M ^{m +} in the above 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}
In the anion part formula (d1-3), Rd ³ 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, and the same group as R ¹⁰¹ in the above formula (b-1) can be mentioned, and a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl can be mentioned. It is preferably a group. Of these, an alkyl fluorinated group is preferable, and the same group as the alkyl fluorinated group of ^{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. It is a chain alkenyl group, and the same group as R ¹⁰¹ in the above formula (b-1) can be mentioned.
Of 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, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, or an isobutyl group. , Tert-Butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of the hydrogen atom of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group, a cyano group or the like.
The alkoxy group in Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and specifically, the alkoxy group having 1 to 5 carbon atoms is a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, or n-. Examples thereof include a butoxy group and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are more preferable.

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

Examples of the cyclic group in Rd ^{4 include those similar to R 101} in the above formula (b-1), from cycloalkanes such as cyclopentane, cyclohexane, adamantan, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group from which one or more hydrogen atoms have been removed, or an aromatic group such as a phenyl group or a naphthyl group is preferable. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in an organic solvent, so that the lithography characteristics are improved. When Rd ⁴ is an aromatic group, the resist composition has excellent light absorption efficiency, and the sensitivity and lithography characteristics are good.

In formula (d1-3), Yd ¹ is a single bond or a divalent linking group.
The ^{divalent linking group in Yd 1} is not particularly limited, but includes a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent and a hetero atom. Examples include valuation linking groups. Examples of these are the same as the divalent linking group containing a heteroatom in ^{Ya x1} in the above-mentioned general formula (a10-u1).
Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

A preferable specific example of the anion portion of the component (d1-3) is shown below.

In the cation part formula (d1-3), M ^{m +} is an m-valent organic cation, which is the same as M ^{m +} in the above 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 of them may be used in combination.
When the resist composition contains the component (D1), the content of the component (D1) in the resist composition is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A). 5 to 8 parts by mass is more preferable, and 1 to 8 parts by mass is further preferable.
When the content of the component (D1) is at least the lower limit of the above-mentioned preferable range, particularly good lithography characteristics and resist pattern shape can be easily obtained. On the other hand, when it is not more than the upper limit value of the above-mentioned preferable range, the sensitivity can be maintained well and the throughput is also excellent.

-Regarding the component (D2) Further, the resist composition of the present embodiment contains a nitrogen-containing organic compound component (hereinafter referred to as "(D2) component") which does not correspond to the above-mentioned component (D1) as the component (D). You may.
The component (D2) is not particularly limited as long as it acts 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 are preferable, and among them, secondary aliphatic amines and tertiary aliphatic amines are more preferable.
The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.
Examples of the aliphatic amine include _{an amine (alkylamine or alkylalcoholamine) in which at least one hydrogen atom of ammonia NH 3} is replaced with an alkyl group or a hydroxyalkyl group having 12 or less carbon atoms, or a cyclic amine.
Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; diethylamine, di-n-propylamine, and the like. Dialkylamines such as di-n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine (triamylamine), Trialkylamines such as tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine , Diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine and other alkyl alcohol amines. Among these, trialkylamines having 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

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

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

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

As the component (D2), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (D2), the content of the component (D2) in the resist composition is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A). .. By setting the content of the component (D2) to the above-mentioned preferable range, the shape of the resist pattern, the stability over time of leaving, and the like are improved.

≪ (C) component ≫
In addition to the components (A) and (F), the resist composition of the present embodiment may further contain a cross-linking agent component (hereinafter, this is also referred to as "component (C)").
By using a resist composition containing the component (C), the contrast between the exposed portion and the unexposed portion of the resist film is further enhanced when the resist pattern is formed, and the resolution performance in the resist pattern formation is improved. LWR (linewise roughness) reduction and lithography characteristics such as shape are further improved.

The component (C) is not particularly limited, and can be arbitrarily selected and used from the cross-linking agents used in the chemically amplified negative resist compositions known so far.
Examples of the component (C) include 2,3-dihydroxy-5-hydroxymethylnorbornane, 2-hydroxy-5,6-bis (hydroxymethyl) norbornane, cyclohexanedimethanol, 4,4'-biphenyldimethanol, 3, Hydroxy groups such as 4,8 (or 9) -trihydroxytricyclodecane, 2-methyl-2-adamanthanol, 1,4-dioxane-2,3-diol, 1,3,5-trihydroxycyclohexane, or Cyclic hydrocarbons having a hydroxyalkyl group or both, or oxygen-containing derivatives thereof can be mentioned.

Further, an amino group-containing compound such as melamine, acetoguanamine, benzoguanamine, urea, ethylene urea, propylene urea, or glycoluril is reacted with formaldehyde or formaldehyde and a lower alcohol, and the hydrogen atom of the amino group is changed to a hydroxymethyl group or a lower alkoxy. Examples thereof include a compound substituted with a methyl group and a compound having an epoxy group.
Of these, those using melamine are used as melamine-based cross-linking agents, those using urea are used as urea-based cross-linking agents, those using alkylene urea such as ethylene urea and propylene urea are used as alkylene urea-based cross-linking agents, and glycol uryl is used. The existing one is called a glycol urea-based cross-linking agent, and the one using a compound having an epoxy group is called an epoxy-based cross-linking agent.
As the component (C), at least one selected from the group consisting of a melamine-based cross-linking agent, a urea-based cross-linking agent, an alkylene urea-based cross-linking agent, a glycol uryl-based cross-linking agent, and an epoxy-based cross-linking agent is preferable, and in particular, a glycol uryl-based component is preferable. Crosslinking agents are preferred.

As a melamine-based cross-linking agent, a compound in which melamine and formaldehyde are reacted to replace the hydrogen atom of the amino group with a hydroxymethyl group, and melamine, formaldehyde and a lower alcohol are reacted to change the hydrogen atom of the amino group to a lower alkoxy. Examples thereof include compounds substituted with a methyl group. Specific examples thereof include hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, hexabutoxybutyl melamine and the like, with hexamethoxymethylmelamine being preferred.

As a urea-based cross-linking agent, a compound in which urea and formaldehyde are reacted to replace a hydrogen atom of an amino group with a hydroxymethyl group, and urea, formaldehyde and a lower alcohol are reacted to change a hydrogen atom of an amino group to a lower alkoxy. Examples thereof include compounds substituted with a methyl group. Specific examples thereof include bismethoxymethylurea, bisethoxymethylurea, bispropoxymethylurea, and bisbutoxymethylurea, with bismethoxymethylurea being preferred.

Examples of the alkyleneurea-based cross-linking agent include compounds represented by the following general formula (C-1).

［式中、Ｒ^５’及びＲ^６’は、それぞれ独立に、水酸基又は低級アルコキシ基である。Ｒ^３’及びＲ^４’は、それぞれ独立に、水素原子、水酸基又は低級アルコキシ基である。ｖは、０〜２の整数である。］

Wherein, R 5 ^'and R ^6' are each independently a hydroxyl group or a lower alkoxy group. R 3 ^'and R ^4' are each independently a hydrogen atom, a hydroxyl group or a lower alkoxy group. v is an integer from 0 to 2. ]

R 5 ^'and R ^6' is a lower alkoxy group, preferably an alkoxy group having 1 to 4 carbon atoms, may be may be linear branched. R 5 ^'and R ^6' may be the same or different from each other, and are preferably the same.
When R 3 ^'and R ^4' is a lower alkoxy group, preferably an alkoxy group having 1 to 4 carbon atoms, it may be may be linear branched. R 3 ^'and R ^4' may be the same or different from each other, and are preferably the same.
v is an integer from 0 to 2, preferably 0 or 1.
As the alkylene urea-based cross-linking agent, a compound having v of 0 (ethylene urea-based cross-linking agent) and / or a compound having v of 1 (propylene urea-based cross-linking agent) are particularly preferable.

The compound represented by the above general formula (C-1) can be obtained by subjecting alkyleneurea and formalin to a condensation reaction, or by reacting this product with a lower alcohol.

Specific examples of the alkyleneurea-based cross-linking agent include, for example, mono and / or dihydroxymethylated ethylene urea, mono and / or dimethoxymethylated ethylene urea, mono and / or diethoxymethylated ethylene urea, mono and / or dipropoxy. Ethylene urea-based cross-linking agents such as methylated ethylene urea, mono and / or dibutoxymethylated ethylene urea; mono and / or dihydroxymethylated propylene urea, mono and / or dimethoxymethylated propylene urea, mono and / or diethoxymethyl Propropylene urea-based cross-linking agents such as propylene urea, mono and / or dipropoxymethylated propylene urea, mono and / or dibutoxymethylated propylene urea; 1,3-di (methoxymethyl) 4,5-dihydroxy-2- Examples thereof include imidazolidinone, 1,3-di (methoxymethyl) -4,5-dimethoxy-2-imidazolidinone.

Examples of the glycoluril-based cross-linking agent include glycoluril derivatives in which the N-position is substituted with one or both of a hydroxyalkyl group and an alkoxyalkyl group having 1 to 4 carbon atoms. Such a glycoluril derivative can be obtained by subjecting glycoluril to formalin by a condensation reaction and by reacting the product with a lower alcohol.
Specific examples of glycol uryl-based cross-linking agents include, for example, mono, di, tri and / or tetrahydroxymethylated glycol uryl; mono, di, tri and / or tetramethoxymethylated glycol uryl; mono, di, tri and / or. Tetraethoxymethylated glycol uryl; mono, di, tri and / or tetrapropoxymethylated glycol uryl; mono, di, tri and / or tetrabutoxymethylated glycol uryl and the like.

The epoxy-based cross-linking agent is not particularly limited as long as it has an epoxy group, and can be arbitrarily selected and used. Among them, those having two or more epoxy groups are preferable. Having two or more epoxy groups improves the cross-linking reactivity.
The number of epoxy groups is preferably 2 or more, more preferably 2 to 4, and most preferably 2.
Suitable epoxy-based cross-linking agents are shown below.

As the component (C), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (C), the content of the component (C) is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the component (A), more preferably 3 to 30 parts by mass. Preferably, 3 to 20 parts by mass is more preferable, and 5 to 15 parts by mass is most preferable.
When the content of the component (C) is at least the lower limit value, cross-linking is sufficiently advanced, and the resolution performance and the lithography characteristics are further improved. Moreover, a good resist pattern with less swelling can be obtained. Further, when it is not more than this upper limit value, the storage stability of the resist composition is good, and the deterioration of the sensitivity with time is likely to be suppressed.

≪ (E) component ≫
The resist composition of the present embodiment comprises an organic carboxylic acid, an oxo acid of phosphorus, and a derivative thereof as arbitrary components for the purpose of preventing deterioration of sensitivity, improving the shape of the resist pattern, 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 the phosphorus oxo acid include phosphoric acid, phosphonic acid, phosphinic acid and the like, and among these, phosphonic acid is particularly preferable.
Examples of the derivative of the oxo acid of phosphorus include an ester in which the hydrogen atom of the oxo acid is replaced with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. Examples include 15 aryl groups.
Examples of the phosphoric acid derivative include phosphoric acid esters such as phosphoric acid di-n-butyl ester and phosphoric acid diphenyl ester.
Examples of the phosphonic acid derivative include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the derivative of phosphinic acid include phosphinic acid ester and phenylphosphinic acid.
In the resist composition of the present embodiment, the component (E) may be used alone or in combination of two or more.
When the resist composition contains the component (E), the content of the component (E) is preferably in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A).

≪ (S) component ≫
The resist composition of the present embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as "(S) component").
The component (S) may be any component as long as it can dissolve each component to be used to form a uniform solution, and any conventionally known solvent for the chemically amplified resist composition may be appropriately used. It can be selected and used.
Examples of the component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone and 2-heptanone; ethylene glycol, diethylene glycol and propylene glycol. , Polyhydric alcohols such as dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, said polyvalent alcohols or having said ester bond. Derivatives of polyhydric alcohols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether and monobutyl ether of compounds or compounds having an ether bond such as monophenyl ether [among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) is preferred]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate. , Esters such as methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethylbenzyl ether, cresylmethyl ether, diphenyl ether, dibenzyl ether, phenitol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, Examples thereof include aromatic organic solvents such as xylene, simene and mesityrene, dimethyl sulfoxide (DMSO) and the like.
In the resist composition of the present embodiment, the component (S) may be used alone or as a mixed solvent of two or more kinds. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferable.
The amount of the component (S) used is not particularly limited, and is appropriately set according to the coating film thickness at a concentration at which the resist composition can be applied to a substrate or the like. Generally, the component (S) 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 of the present embodiment further comprises an additive that is optionally miscible, such as an additional resin, a surfactant, a dissolution inhibitor, a plasticizer, a stabilizer, a coloring agent for improving the performance of the resist film. Agents, anti-halation agents, dyes and the like can be appropriately contained.

(Resist pattern forming method)
The resist pattern forming method according to the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition of the above-described embodiment, a step of exposing the resist film, and a step of exposing the resist film. This is a method having a step of forming a resist pattern by alkaline-developing the resist film of.
An embodiment of such a resist pattern forming method includes, for example, a resist pattern forming method performed as follows.

First, the resist composition of the above-described embodiment is applied onto a support with a spinner or the like, and a bake (post-apply bake (PAB)) treatment is carried out, for example, under a temperature condition of 80 to 150 ° C. for 40 to 120 seconds, preferably. Is applied for 60 to 90 seconds to form a resist film.
Next, the resist film is exposed through a mask (mask pattern) on which a predetermined pattern is formed by using an exposure device such as an electron beam drawing device or an EUV exposure device, or an electron beam that does not pass through the mask pattern. After performing selective exposure by drawing or the like by direct irradiation, baking (post-exposure baking (PEB)) treatment is performed, for example, under a temperature condition of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to 90 seconds.
Next, the resist film is alkaline-developed. The alkaline developing process is carried out using an alkaline developer.
After the development treatment, a rinsing treatment is preferably performed. The rinsing treatment is preferably a water rinse using pure water.
Drying is performed after the alkali development treatment or the rinsing treatment. In some cases, a baking process (post-baking) may be performed after the development process.
In this way, the resist pattern can be formed.

The support is not particularly limited, and conventionally known ones can be used. Examples thereof include a substrate for electronic components and a support having a predetermined wiring pattern formed therein. More specifically, silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, glass substrates, and the like can be mentioned. As the material of the wiring pattern, for example, copper, aluminum, nickel, gold and the like can be used.
Further, the support may be one in which an inorganic and / or organic film is provided on the substrate as described above. Examples of the inorganic film include an inorganic antireflection film (inorganic BARC). Examples of the organic film include an organic antireflection film (organic BARC) and an organic film such as a lower organic film in the multilayer resist method.
Here, in the multilayer resist method, at least one layer of an organic film (lower layer organic film) and at least one layer of a resist film (upper layer resist film) are provided on a substrate, and a resist pattern formed on the upper layer resist film is used as a mask. It is a method of patterning an lower organic film, and is said to be able to form a pattern having a high aspect ratio. That is, according to the multilayer resist method, since the required thickness can be secured by the lower organic film, the resist film can be thinned and a fine pattern having a high aspect ratio can be formed.
The multilayer resist method basically includes 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. It can be divided into a method of forming a multilayer structure of three or more layers provided with (metal thin film, etc.) (three-layer resist method).

Wavelength used for the exposure is not particularly limited, ArF excimer laser, KrF excimer laser, _{F 2} excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays It can be done using radiation. The resist composition of the present embodiment described above is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV, more useful for ArF excimer laser, EB or EUV, and is for EB or EUV. Especially useful as.

The exposure method of the resist film may be a normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or an immersion exposure (Liquid Imaging 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 the refractive index of air, and exposure (immersion exposure) is performed in that state. This 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 fluorine-based compounds 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 main components.} Examples thereof include liquids, those having a boiling point of 70 to 180 ° C., and more preferably those having a boiling point of 80 to 160 ° C. It is preferable that the fluorine-based inert liquid has a boiling point in the above range because the medium used for immersion can be removed by a simple method after the end of exposure.
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.
Further, specifically, the perfluoroalkyl ether compound may include perfluoro (2-butyl-tetrahydrofuran) (boiling point 102 ° C.), and the perfluoroalkylamine compound may include perfluorotributylamine (perfluorotributylamine). Boiling point 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 alkaline developer used in the developing process in the alkaline developing process include an aqueous solution of 0.1 to 10 mass% tetramethylammonium hydroxide (TMAH).

The alkaline development process can be carried out by a known developing method. For example, a method of immersing the support in a developing solution for a certain period of time (dip method), or a method in which the developing solution is raised on the surface of the support by surface tension and constant. A method of standing still for a while (paddle method), a method of spraying the developer on the surface of the support (spray method), a method of spraying the developer on the support rotating at a constant speed while scanning the developer dispensing nozzle at a constant speed. Examples include a method of continuing to apply (dynamic dispense method).

The rinsing treatment (cleaning treatment) using the rinsing liquid can be carried out by a known rinsing method. Examples of the rinsing treatment method include a method of continuously applying the rinsing liquid onto a support rotating at a constant speed (rotary coating method), a method of immersing the support in the rinsing liquid for a certain period of time (dip method), and the like. Examples thereof include a method of spraying a rinse liquid on the surface of the support (spray method).

The resist composition of the present embodiment described above includes a polymer compound (component (A1)) having a structural unit (constituent unit (a0)) derived from the compound represented by the general formula (a0-1). It contains a fluororesin component ((F1) component) having a structural unit (f1) containing a base dissociable group.
In the manufacture of semiconductor elements and liquid crystal display elements, the pattern is rapidly miniaturized, and a resist material having higher resolution performance is required. On the other hand, in the conventional chemically amplified resist composition containing a cross-linking agent component, the cross-linking efficiency of the resist film exposed portion can be improved by increasing the blending amount of the cross-linking agent component or the acid generator component. I came. However, when the blending amount of the cross-linking agent component or the acid generator component is increased, the solubility of the unexposed portion of the resist film in the developing solution is lowered, so that the developing contrast is reduced and the resolution performance is insufficient. rice field. Further, if the amount of the cross-linking agent component or the acid generator component is excessive, there is a problem that it becomes difficult to form a resist film.
In the resist composition of the present embodiment described above, the cross-linking efficiency is enhanced by introducing the structural unit (a0). In addition, during alkaline development in resist pattern formation, the introduction of a structural unit (f1) containing a base dissociable group enhances the hydrophilicity of the resist film surface and enhances the solubility of the unexposed portion of the resist film in an alkaline developer. , The contrast between the exposed portion and the unexposed portion of the resist film is further improved. Due to the synergistic action of the combination of the polymer compound having the structural unit (a0) and the component (F1) having the structural unit (f1), the resolution performance is particularly high in lithography using an electron beam or EUV. It is presumed that improvement will be achieved.

Further, according to the resist composition of the present embodiment described above, the content of the metal in the resist composition can be suppressed to a low level, and the electrical characteristics and reliability of the finally manufactured semiconductor element and liquid crystal display element can be improved. .. In addition, it facilitates high integration. Examples of such a resist composition include those in the resist composition of the present embodiment described above that do not contain a polymer compound having a structural unit derived from a metal complex.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these examples.
In this embodiment, the compound represented by the chemical formula (1) is referred to as “compound (1)”, and the compounds represented by other chemical formulas are also referred to in the same manner.

<Production example of polymer compound>
The polymer compounds A1-1 to A1-33 and A2-1 used in this example are radically polymerized by using monomers for inducing the following structural units constituting each polymer compound in a predetermined molar ratio, respectively. Obtained by letting.

For the polymer compounds A1-1 to A1-33 and A2-1, the copolymer composition ratio of the polymer compound (ratio (molar ratio) of each structural unit in the polymer compound) determined by ^{13 C-NMR,} Tables 1 and 2 also show the mass average molecular weight (Mw) and the molecular weight dispersion (Mw / Mn) in terms of standard polystyrene obtained by GPC measurement.

<Preparation of resist composition>
(Examples 1-49, Comparative Examples 1-4)
Each component shown in Tables 3 to 6 was mixed and dissolved to prepare a resist composition (solid content concentration: 1.5% by mass) of each example.

In Tables 3 to 6, each abbreviation has the following meaning. The value in [] is the blending amount (part by mass).
(A) -1 to (A) -33: The above-mentioned polymer compounds A1-1 to A1-33.
(A) -34: The above-mentioned polymer compound A2-1.

(F) -1: Fluorine-containing polymer compound represented by the following chemical formula (F1-1). The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 6800, and the molecular weight dispersion (Mw / Mn) is 1.54. ^{13 The} copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by C-NMR is l / m = 69.1 / 30.9.
(F) -2: A fluorine-containing polymer compound represented by the following chemical formula (F1-2). The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 17,300, and the molecular weight dispersion (Mw / Mn) is 1.73. ^{13 The} copolymerization composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by C-NMR is l / m = 82.0 / 18.0.

(B) -1 to (B) -10: An acid generator composed of compounds represented by the following chemical formulas (b-1-1) to (b-1-10), respectively.

(D) -1 to (D) -4: A photodisintegrating base composed of compounds represented by the following chemical formulas (D1-1) to (D1-4), respectively.
(D) -5: Trioctylamine.

(Add) -1: A cross-linking agent composed of a compound represented by the following chemical formula (Add-1).

(S) -1: Mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 20/80 (mass ratio).

<Formation of resist pattern>
Each of the resist compositions of each example was applied to an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS) using a spinner, and prebaked (PAB) at a temperature of 110 ° C. for 60 seconds on a hot plate. The treatment was carried out and dried to form a resist film having a film thickness of 50 nm.
Next, for the resist film, an electron beam drawing apparatus JEOL-JBX-9300FS (manufactured by JEOL Ltd.) was used, and the target size was set to a 1: 1 line-and-space pattern with a line width of 50 to 26 nm at an acceleration voltage of 100 kV. (Hereinafter referred to as “LS pattern”), drawing (exposure) was performed. Then, a post-exposure heating (PEB) treatment was performed at 110 ° C. for 60 seconds.
Then, at 23 ° C., alkali development was carried out for 60 seconds using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.).
Then, water rinse was performed for 15 seconds using pure water.
As a result, a 1: 1 LS pattern with a line width of 50 to 26 nm was formed.

[Evaluation of Optimal Exposure (Eop)]
^{The optimum exposure amount Eop (μC / cm 2} ) at which the target size LS pattern is formed was determined by the resist pattern forming method. This is shown in Tables 7 to 10 as "Eop (μC / cm ^2)".

[Evaluation of resolution]
The limit resolution in the above Eop, specifically, the minimum dimension of the pattern that resolves without collapsing when the exposure amount is gradually increased from the optimum exposure amount Eop to form an LS pattern, is a scanning electron microscope. It was obtained using S-9380 (manufactured by Hitachi High Technology Co., Ltd.). This is shown in Tables 7 to 10 as "resolution performance (nm)".

[Evaluation of LWR (Linewise Roughness)]
For the LS pattern formed in the above <Formation of resist pattern>, 3σ, which is a scale indicating LWR, was determined. This is shown in Tables 7 to 10 as "LWR (nm)".
"3σ" is a standard deviation obtained by measuring 400 line positions in the longitudinal direction of the line with a scanning electron microscope (acceleration voltage 800V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). It shows a triple value (3σ) (unit: nm) of (σ).
The smaller the value of 3σ, the smaller the roughness of the side wall of the line, which means that an LS pattern having a more uniform width was obtained.

[Evaluation of LS pattern shape]
The shape of the LS pattern formed by the above <resist pattern formation> was observed by a length measuring SEM (scanning electron microscope, acceleration voltage 800V, trade name: SU-8000, manufactured by Hitachi High-Technologies Corporation), and the following Evaluation was made based on the evaluation criteria. The results are shown in Tables 7 to 10 as "shapes".
Evaluation Criteria ○: Rectangular ×: Head or taper

From the results shown in Tables 7 to 10, according to the resist compositions of Examples 1 to 49 to which the present invention is applied, it is possible to form a resist pattern having a good shape with high resolution and reduced roughness in the formation of the resist pattern. , Can be confirmed.

Claims (5)

A resist composition that generates an acid upon exposure and changes its solubility in a developing solution by the action of the acid.
It contains a base material component (A) whose solubility in a developing solution changes due to the action of an acid, and a fluorine additive component (F) which exhibits degradability in an alkaline developing solution.
The base material component (A) contains a polymer compound (A1) having a structural unit derived from a compound represented by the following general formula (a0-1).
The fluorine additive component (F) is a resist composition containing a fluororesin component (F1) having a structural unit (f1) containing a base dissociative group.

[In the formula, Ra ^x0 is a polymerizable group-containing group. Wa ^x0 is an aromatic hydrocarbon group having a (n _{ax0 + 1) valence.} However, a fused ring structure may be formed by ^{Ra x0} and Wa ^x0. n _ax0 is an integer of 1 to 3. Ya ^x01 is a carbonyl group or a single bond. Ra ^x01 is an aliphatic hydrocarbon group or a hydrogen atom. ] The resist composition according to claim 1, wherein the structural unit (f1) is a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2). ..

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms, respectively. X is a divalent linking group that does not have an acid dissociative site. _Aryl is a divalent aromatic cyclic group that may have a substituent. X ₀₁ is a single bond or divalent linking group. R ² is an organic group each independently having a fluorine atom. ] The resist composition according to claim 1 or 2, wherein the content of the fluororesin component (F1) is 0.5 to 10 parts by mass with respect to 100 parts by mass of the base material component (A). The resist composition according to any one of claims 1 to 3, further comprising a photodisintegrating base (D1) that is decomposed by exposure and loses acid diffusion controllability. A step of forming a resist film using the resist composition according to any one of claims 1 to 4 on a support, a step of exposing the resist film, and an alkali development of the resist film after the exposure. A resist pattern forming method comprising a step of forming a resist pattern.