JP7274937B2 - Resist composition and resist pattern forming method - Google Patents

Description

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

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed to light, and a development process is performed to form a resist pattern having a predetermined shape on the resist film. a process is performed. A resist material in which the exposed portion of the resist film becomes soluble in the developer is called a positive type, and a resist material in which the exposed portion of the resist film becomes insoluble in the developer is called a negative type.
2. Description of the Related Art In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, advances in lithography technology have led to rapid miniaturization of patterns. As a technique for miniaturization, generally, the wavelength of the exposure light source is shortened (the energy is increased). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, semiconductor devices using KrF excimer lasers and ArF excimer lasers are being mass-produced. In addition, EUV (extreme ultraviolet rays), EB (electron beam), X-rays, etc., which have a shorter wavelength (higher energy) than these excimer lasers, are also being studied.

Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions.
Conventionally, as a resist material satisfying such requirements, a chemically amplified resist composition containing a base component whose solubility in a developing solution is changed by the action of an acid and an acid generator component which generates an acid upon exposure. is used.
For example, when the developer is an alkaline developer (alkaline 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 acid and an acid-generating are commonly used. When a resist film formed using such a resist composition is subjected to selective exposure during resist pattern formation, acid is generated from the acid generator component in the exposed area, and the action of the acid increases the polarity of the base resin. As a result, the exposed portion of the resist film becomes soluble in an alkaline developer. Therefore, by alkali development, a positive pattern is formed in which the unexposed portion of the resist film remains as a pattern.
On the other hand, when such a chemically amplified resist composition is applied to a solvent development process using a developer containing an organic solvent (organic developer), an increase in the polarity of the base resin results in relatively organic development. Since the solubility in the liquid is lowered, the unexposed portion of the resist film is dissolved and removed by the organic developer, forming a negative resist pattern in which the exposed portion of the resist film remains as a pattern. Such a solvent development process for forming a negative resist pattern is sometimes called a negative development process.

A base resin used in a chemically amplified resist composition generally has a plurality of constitutional units in order to improve lithography properties and the like.
For example, in the case of a resin component whose solubility in an alkaline developer is increased by the action of an acid, a structural unit containing an acid-decomposable group that is decomposed and increased in polarity by the action of an acid generated from an acid generator or the like is used. In addition, a structural unit containing a lactone-containing cyclic group, a structural unit containing a polar group such as a hydroxyl group, and the like are used in combination.

Also, in the formation of a resist pattern, the behavior of acid generated from the acid generator component upon exposure is considered to be one factor that greatly affects lithography properties.
A wide variety of acid generators have been proposed so far for use in chemically amplified resist compositions. For example, onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, disulfone-based acid generators, etc. It has been known.
As the onium salt-based acid generator, those having an onium ion such as triphenylsulfonium in the cation portion are mainly used. The anion part of the onium salt-based acid generator is generally an alkylsulfonate ion or a fluorinated alkylsulfonate ion in which some or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. .
In addition, in order to improve lithography properties in forming a resist pattern, an onium salt-based acid having an anion having a specific structure including a condensed ring of a bridged ring and another ring as an anion portion of the onium salt-based acid generator. Generating agents have also been proposed (see, for example, Patent Document 1).

WO2017/179727

As lithography technology advances further and resist patterns become increasingly finer, for example, electron beam and EUV lithography aims to form fine patterns of several tens of nanometers. As the resist pattern dimension becomes smaller, the resist composition is required to have higher sensitivity to the exposure light source and better lithography properties such as reduced roughness. Further, for example, in a line-and-space pattern, the cross-sectional shape of the pattern is also required to be rectangular.
However, in resist compositions containing conventional onium salt-based acid generators such as those described above, although roughness can be reduced, it is sometimes difficult to control the rectangularity of patterns.

The present invention has been made in view of the above circumstances, and provides a resist composition and a method of forming a resist pattern using the resist composition, which further reduces roughness and improves the rectangularity of the cross-sectional shape of the resist pattern. The task is to provide

In order to solve the above problems, the present invention employs the following configurations.
That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, wherein the solubility in the developer changes due to the action of the acid. and a compound (BD1) consisting of an anion portion and a cation portion represented by the following general formula (bd1), and the resin component is represented by the following general formula (a0-n-1): It is a resist composition having a structural unit (a0) containing a partial structure having a

［式中、Ｒ^１は炭素数１～１２のフッ素化アルキル基である。Ｒ^２はフッ素原子を有してもよい炭素数１～１２の有機基又は水素原子である。＊は結合手を示す。］

[In the formula, R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms. R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. * indicates a bond. ]

［式中、Ｒｘ^１～Ｒｘ^４は、それぞれ独立に、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は２個以上が相互に結合して環構造を形成していてもよい。Ｒｙ^１～Ｒｙ^２は、それぞれ独立に、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は相互に結合して環構造を形成していてもよい。

は二重結合又は単結合である。Ｒｚ^１～Ｒｚ^４は、それぞれ独立に、原子価が許容する場合、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は２個以上が相互に結合して環構造を形成していてもよい。但し、Ｒｘ^１～Ｒｘ^４、Ｒｙ^１～Ｒｙ^２及びＲｚ^１～Ｒｚ^４のうち少なくとも１個はアニオン基を有し、アニオン部全体でｎ価のアニオンとなる。ｎは１以上の整数である。ｍは１以上の整数であって、Ｍ^ｍ＋は、ｍ価の有機カチオンを表す。］

[In the formula, Rx ¹ to Rx ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or two or more of them combine to form a ring structure; good too. Ry ¹ to Ry ² each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure.

is a double bond or a single bond. Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have However, at least one of Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the entire anion part becomes an n-valent anion. n is an integer of 1 or more. m is an integer of 1 or more, and M ^m+ represents an m-valent organic cation. ]

A second aspect of the present invention comprises the steps of forming a resist film on a support using the resist composition according to the first aspect, exposing the resist film, and exposing the resist film after the exposure. A resist pattern forming method comprising a step of developing to form a resist pattern.

According to the resist composition of the present invention, it is possible to form a resist pattern in which the roughness is further reduced and the rectangularity of the cross-sectional shape of the resist pattern is improved.

In the present specification and claims, "aliphatic" is defined relative to aromatic to mean groups, compounds, etc. that do not possess aromatic character.
"Alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the "alkylene group" includes straight-chain, branched-chain and cyclic divalent saturated hydrocarbon groups.
A "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group are substituted with halogen atoms, and the halogen atoms include fluorine, chlorine, bromine and iodine atoms.
A "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which some or all of the hydrogen atoms of an alkyl group or alkylene group have been substituted with fluorine atoms.
A "structural unit" means a monomer unit (monomeric unit) that constitutes a polymer compound (resin, polymer, copolymer).
When describing “optionally having a substituent” or “optionally having a substituent”, when a hydrogen atom (—H) is substituted with a monovalent group, or when a methylene group (—CH ₂ -) is substituted with a divalent group.
“Exposure” is a concept that includes irradiation of radiation in general.

The "base material component" is an organic compound having film-forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved, and in addition, it becomes easy to form a nano-level resist pattern. The organic compounds used as the base component are roughly classified into non-polymers and polymers. As the non-polymer, one having a molecular weight of 500 or more and less than 4000 is usually used. Hereinafter, the term "low-molecular-weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4,000. As the polymer, those having a molecular weight of 1000 or more are usually used. Hereinafter, "resin", "polymer compound" or "polymer" refers to a polymer having a molecular weight of 1000 or more. As the molecular weight of the polymer, the weight average molecular weight of polystyrene conversion by GPC (gel permeation chromatography) shall be used.

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

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

A “structural unit derived from hydroxystyrene” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene. A “structural unit derived from a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of a hydroxystyrene derivative.
"Hydroxystyrene derivative" is a concept including hydroxystyrene in which the α-position hydrogen atom is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. Derivatives thereof include those obtained by substituting the hydrogen atom of the hydroxyl group of hydroxystyrene with an organic group; Examples include those in which a substituent other than a hydroxyl group is bonded to the benzene ring of good hydroxystyrene. In addition, the α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents at the α-position in the α-substituted acrylic acid ester.

A “structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative” means a structural unit formed by cleavage of an ethylenic double bond of vinyl benzoic acid or a vinyl benzoic acid derivative.
The concept of "vinyl benzoic acid derivative" includes those in which the α-position hydrogen atom of vinyl benzoic acid is substituted with other substituents such as alkyl groups and halogenated alkyl groups, and derivatives thereof. Derivatives thereof include those in which the hydrogen atom of the carboxy group of vinylbenzoic acid, which may be substituted with a substituent at the α-position, is substituted with an organic group; Examples thereof include vinyl benzoic acid in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinyl benzoic acid. In addition, the α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.

"Styrene derivative" is a concept including those in which the α-position hydrogen atom of styrene is substituted with other substituents such as alkyl groups and halogenated alkyl groups, and derivatives thereof. Derivatives thereof include those in which a substituent is bonded to the benzene ring of hydroxystyrene in which the α-position hydrogen atom may be substituted by a substituent. In addition, the α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.
A "structural unit derived from styrene" and a "structural unit derived from a styrene derivative" mean a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.

The alkyl group as the α-position substituent 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 halogenated alkyl group as a substituent at the α-position specifically includes a group in which some or all of the hydrogen atoms in the above "alkyl group as a substituent at the α-position" are substituted with halogen atoms. be done. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferred.
Further, the hydroxyalkyl group as the α-position substituent specifically includes a group in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the α-position substituent” are substituted with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1-5, most preferably 1.

In the present specification and claims, some structures represented by chemical formulas may have asymmetric carbon atoms and may have enantiomers or diastereomers. In that case, one chemical formula represents those isomers. Those isomers may be used singly or as a mixture.

(Resist composition)
The resist composition according to the first aspect of the present invention generates acid upon exposure, and the action of the acid changes the solubility in the developer, and the action of the acid changes the solubility in the developer. Containing a variable base component (A) (hereinafter also referred to as "(A) component") and a compound (BD1) represented by general formula (bd1) (hereinafter also referred to as "(BD1) component") .

An embodiment of such a resist composition is a resist composition containing the component (A) and an acid generator component (B) that generates an acid upon exposure (hereinafter also referred to as "component (B)"). is mentioned. Preferably, in addition to the components (A) and (B), a base component (hereinafter also referred to as "component (D)") traps the acid generated from the component (B) upon exposure (i.e., controls diffusion of the acid). ) is further included.
In the resist composition of the present embodiment, the component (A) is a resin component (A1) (hereinafter "(A1 ) component”).
Component (BD1) can be used as component (B) or component (D) by selecting an anionic group in the molecule.

When a resist film is formed using the resist composition of the present embodiment and the resist film is subjected to selective exposure, acid is generated from the component (B) in the exposed portion of the resist film, and the acid While the solubility of the component (A) in the developer changes due to the action of the resist film, the solubility of the component (A) in the developer does not change in the unexposed areas of the resist film. There is a difference in solubility in the developer between them. Therefore, when the resist film is developed, if the resist composition is positive, the exposed portion of the resist film is dissolved and removed to form a positive resist pattern, and if the resist composition is negative, the resist film is not formed. The exposed portion is dissolved and removed to form a negative resist pattern.

In this specification, a resist composition that forms a positive resist pattern by dissolving and removing the exposed portion of the resist film is referred to as a positive resist composition, and forming a negative resist pattern by dissolving and removing the unexposed portion of the resist film. A resist composition that does so is called a negative resist composition. The resist composition of this embodiment may be a positive resist composition or a negative resist composition. In addition, the resist composition of the present embodiment may be for an alkali development process using an alkali developer for development treatment at the time of resist pattern formation, and a developer containing an organic solvent (organic developer) for the development treatment. for solvent development processes using

The resist composition of this embodiment has an acid-generating ability to generate an acid upon exposure, and in addition to the component (B), the component (A) may also generate an acid upon exposure.
When the component (A) generates an acid upon exposure, this component (A) is a "base component that generates an acid upon exposure and changes its solubility in a developer by the action of the acid".
When the component (A) is a substrate component that generates an acid upon exposure and the solubility in a developer changes due to the action of the acid, the component (A1) described above generates an acid upon exposure and It is preferably a polymer compound whose solubility in a developer is changed by the action of an acid. Examples of such polymer compounds include resins having structural units that generate acid upon exposure. A known monomer can be used as a monomer that induces a structural unit that generates an acid upon exposure.

<(A) Component>
In the resist composition of the present embodiment, component (A) is a base component whose solubility in a developer changes under the action of acid, and contains component (A1) described above. By using the component (A1), the polarity of the base material component changes before and after exposure, so that good development contrast can be obtained not only in the alkali development process but also in the solvent development process.

When an alkali development process is applied, the substrate component containing the component (A1) is sparingly soluble in an alkaline developer before exposure. The action of increases the polarity and increases the solubility in an alkaline developer. Therefore, in the formation of a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed to light, the exposed portion of the resist film changes from poorly soluble to soluble in an alkaline developer. On the other hand, since the unexposed portion of the resist film remains insoluble in alkali, a positive resist pattern is formed by alkali development.

On the other hand, when a solvent development process is applied, the base material component containing the component (A1) is highly soluble in an organic developer before exposure. , the action of the acid increases the polarity and reduces the solubility in an organic developer. Therefore, in the formation of a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed to light, the exposed portion of the resist film changes from soluble to poorly soluble in an organic developer. On the other hand, the unexposed portion of the resist film remains soluble and does not change. Therefore, by developing with an organic developer, it is possible to create a contrast between the exposed portion and the unexposed portion, resulting in a negative resist pattern. It is formed.

In the resist composition of this embodiment, the component (A) may be used alone or in combination of two or more.

• Component (A1) Component (A1) has a structural unit (a0) containing a partial structure represented by general formula (a0-n-1) described below. Such component (A1) may have other structural units in addition to the structural unit (a0), if necessary.
Component (A1) includes, for example, a copolymer having a structural unit (a0) and optionally other structural units (hereinafter, this copolymer is referred to as "(A1-1) component"). mentioned.

<<Constituent unit (a0)>>
The (A1) component has a structural unit (a0) containing a partial structure represented by general formula (a0-n-1).

［式中、Ｒ^１は炭素数１～１２のフッ素化アルキル基である。Ｒ^２はフッ素原子を有してもよい炭素数１～１２の有機基又は水素原子である。＊は結合手を示す。］

[In the formula, R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms. R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. * indicates a bond. ]

In formula (a0-n-1), R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms.
A fluorinated alkyl group having 1 to 12 carbon atoms is a group in which some or all of the hydrogen atoms of an alkyl group having 1 to 12 carbon atoms have been substituted with fluorine atoms. The alkyl group may be linear or branched.
Specific examples of linear fluorinated alkyl groups having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group and decyl group. , an undecyl group, and a dodecyl group in which some or all of the hydrogen atoms are substituted with fluorine atoms. Specific examples of branched fluorinated alkyl groups having 1 to 12 carbon atoms include 1-methylethyl group, 1,1-dimethylethyl group, 1-methylpropyl group, 2-methylpropyl group and 1-methylbutyl 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group Examples thereof include groups partially or wholly substituted with fluorine atoms.

As the fluorinated alkyl group having 1 to 12 carbon atoms for R ¹ , among the above, a fluorinated alkyl group having 1 to 5 carbon atoms is more preferable, and specifically a trifluoromethyl group is particularly preferable.

In the above formula (a0-n-1), R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom.

The organic group having 1 to 12 carbon atoms which may have a fluorine atom for R ² includes a monovalent hydrocarbon group which may have a substituent.
Hydrocarbon groups include linear or branched alkyl groups and cyclic hydrocarbon groups. Examples of the linear or branched alkyl group include the same fluorinated alkyl groups having 1 to 12 carbon atoms as R ¹ .

When R ² is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically includes adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When the cyclic hydrocarbon group for R ² is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. Specific examples of the aromatic hydrocarbon group include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, phenanthrene, biphenyl, and fluorene.

The organic group having 1 to 12 carbon atoms for R ² may have a substituent other than a fluorine atom. Examples of the substituent include hydroxy group, carboxy group, halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), alkyloxycarbonyl group and the like. be done.

R ² is preferably a fluorinated alkyl group having 1 to 12 carbon atoms, more preferably a fluorinated alkyl group having 1 to 5 carbon atoms, and even more preferably a trifluoromethyl group.

The structural unit (a0) containing the partial structure represented by the general formula (a0-n-1) is a compound represented by the following general formula (a0-1) in which the polymerizable group at the W ¹ site is attached to the main chain. The converted structural unit (a0-1), or the structural unit (a0-2) in which the polymerizable group at the ^W2 site in the compound represented by the following general formula (a0-2) is converted to the main chain is preferred.

［式中、Ｒ^１は炭素数１～１２のフッ素化アルキル基である。Ｒ^２はフッ素原子を有してもよい炭素数１～１２の有機基又は水素原子である。Ｗ^１及びＷ^２は、重合性基含有基である。Ｙ_ａ０１ ^ｘ０は、単結合又は（ｎ_ａ０１＋１）価の連結基である。Ｙ_ａ０１ ^ｘ０とＷ^１とは縮合環を形成していてもよい。Ｙ_ａ０２ ^ｘ０は、単結合又は（ｎ_ａ０２＋１）価の連結基である。ｎ_ａ０１及びｎ_ａ０２は、１～３の整数である。］

[In the formula, R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms. R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. W ¹ and W ² are polymerizable group-containing groups. Y _a01 ^x0 is a single bond or a (n _a01 +1)-valent linking group. Y _a01 ^x0 and W ¹ may form a condensed ring. Y _a02 ^x0 is a single bond or a (n _a02 +1)-valent linking group. n _a01 and n _a02 are integers of 1-3. ]

In the above formulas (a0-1) and (a0-2), R ¹ and R ² are the same as described for (a0-n-1) above.

In formulas (a0-1) and (a0-2), W ¹ and W ² are polymerizable group-containing groups.
The “polymerizable group” at the W ¹ and W ² sites is a group that enables a compound having a polymerizable group to polymerize by radical polymerization or the like, for example, a multiple bond between carbon atoms such as an ethylenic double bond. A group containing a bond.
"The polymerizable group was converted to the main chain" means that the multiple bond in the polymerizable group is cleaved to form the main chain of the structural unit (a0). For example, in the case of a monomer having an ethylenic double bond, it means that the ethylenic double bond is cleaved and single bonds between carbon atoms form the main chain.

Examples of polymerizable groups at ^W1 and ^W2 sites include vinyl group, allyl group, acryloyl group, methacryloyl group, fluorovinyl group, difluorovinyl group, trifluorovinyl group, difluorotrifluoromethylvinyl group, and trifluoroallyl group. , perfluoroallyl group, trifluoromethylacryloyl group, nonylfluorobutylacryloyl group, vinyl ether group, fluorine-containing vinyl ether group, allyl ether group, fluorine-containing allyl ether group, styryl group, vinyl naphthyl group, fluorine-containing styryl group, fluorine-containing group vinylnaphthyl group, norbornenyl group, fluorine-containing norbornenyl group, silyl group and the like.
The polymerizable group-containing group may be a group composed only of a polymerizable group, or a group composed of a polymerizable group and a group other than the polymerizable group. Groups other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.

Suitable examples of W ¹ and W ² include groups represented by the chemical formula: CH ₂ =C(R)-Ya ^x0 -. In this chemical formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya ^x0 is a single bond or 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, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or a methyl group in terms of industrial availability, and a methyl group. Especially preferred.

In the above chemical formula, the divalent linking group for Ya ^x0 is not particularly limited, but is preferably a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, or the like. It is mentioned as.

- A divalent hydrocarbon group which may have a substituent:
When Ya ^x0 is an optionally substituted divalent hydrocarbon group, 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 linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing rings in their structures.

... 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 Numbers 1 to 4 are more preferred, and carbon numbers 1 to 3 are most preferred.
As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specifically, a methylene group [ _--CH.sub.2-- ], an ethylene group [--( _CH.sub.2 ) _.sub.2-- ], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -] and the like.
The branched chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) _2- , -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups;- 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 Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ - and -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples 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 preferred.

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

... Aliphatic hydrocarbon group containing a ring in its structure The aliphatic hydrocarbon group containing a ring in its structure is a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure. (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, the cyclic aliphatic groups in which a group hydrocarbon group intervenes in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include those mentioned above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
A 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 include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

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

Aromatic Hydrocarbon Group in Ya ^x0 The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more 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; mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.
Specific examples of the aromatic hydrocarbon group include groups obtained by removing two hydrogen atoms from the above aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); aromatic compounds containing two or more aromatic rings A group obtained by removing two hydrogen atoms from (e.g., biphenyl, fluorene, etc.); One of the hydrogen atoms of the group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) A group in which one 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, a hydrogen from an arylalkyl group such as a 2-naphthylethyl group) group from which one atom has been further removed), and the like. The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

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

- A bivalent linking group containing a heteroatom:
When Ya ^x0 is a divalent linking group containing a hetero atom, the linking group is preferably -O-, -C(=O)-O-, -C(=O)-, -OC (=O) -O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group ), -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, general 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 a group represented by —Y ²¹ —S(=O) ₂ —O—Y ²² — [wherein Y ²¹ and Y ²² each independently have a substituent and is a divalent hydrocarbon group, O is an oxygen atom, and m″ is an integer of 0-3. ] and the like.
The divalent linking group containing the heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH )—, the H may be substituted with a substituent such as an alkyl group or acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
general formulas -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 -, Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent. (divalent hydrocarbon group optionally having substituent(s)).
Y ²¹ is preferably a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkylene group, more preferably a straight-chain alkylene group having 1 to 5 carbon atoms, particularly a methylene group or an ethylene group. preferable.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a straight-chain alkyl group having 1 to 5 carbon atoms, more preferably a straight-chain alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula -[Y ²¹ -C(=O)-O] _m″ -Y ²² -, m″ is an integer of 0 to 3, preferably an integer of 0 to 2, and 0 or 1 is more preferred, and 1 is particularly preferred. That is, the group represented by the formula -[Y ²¹ -C(=O)-O] _m″ -Y ²² - is represented by the formula -Y ²¹ -C(=O)-O-Y ²² - is particularly preferred, and among these, a group represented by the formula —(CH ₂ ) _a′ —C(═O)—O—(CH ₂ ) _b′ —, in which a′ is 1 to 10 is an integer of 1 to 8, preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, and 1 to 8 An integer is preferred, an integer from 1 to 5 is more preferred, 1 or 2 is more preferred, and 1 is most preferred.

Among the above, Ya ^x0 includes an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene groups, combinations thereof, or single bonds, among which ester bonds [-C(=O)-O-, -OC(=O)-], linear or branched or a combination thereof, or a single bond, and an ester bond [-C(=O)-O-, -OC(=O)-] and a single bond are particularly preferred.

In the above formula (a0-1), Y _a01 ^x0 is a single bond or (n _a01 +1)-valent, that is, a divalent, trivalent or tetravalent linking group.

The divalent linking group for Y _a01 ^x0 is the same as described for Ya ^x0 above.

The trivalent linking group for Y _a01 ^x0 includes a group obtained by removing one hydrogen atom from the divalent linking group for Y _a01 ^x0 , and a group obtained by further bonding the divalent linking group to the divalent linking group. etc.

Examples of the tetravalent linking group for Y _a01 ^x0 include a group obtained by removing two hydrogen atoms from the divalent linking group for Y _a01 ^x0 .

Y _a01 ^x0 and W ¹ may form a condensed ring.
When Y _a01 ^x0 and W ¹ form a condensed ring, examples of the ring structure include a condensed ring of an alicyclic hydrocarbon and an aromatic hydrocarbon. The condensed ring formed by Y _a01 ^x0 and W ¹ may have a heteroatom.
The alicyclic hydrocarbon portion in the condensed ring formed by Y _a01 ^x0 and W ¹ may be monocyclic or polycyclic.
The condensed ring formed by Y _a01 ^x0 and W ¹ includes a condensed ring formed by the polymerizable group at W ¹ site and Y _a01 ^x0 , and a group other than the polymerizable group at W ¹ site and Y _a01 ^x0 . A condensed ring formed by Specifically, a bicyclic condensed ring of a cycloalkene and an aromatic ring, a tricyclic condensed ring of a cycloalkene and two aromatic rings, a cycloalkane having a polymerizable group as a substituent and an aromatic ring Condensed rings, tricyclic condensed rings of a cycloalkane having a polymerizable group as a substituent and an aromatic ring, and the like can be mentioned.

The condensed ring formed by Y _a01 ^x0 and W ¹ may have a substituent. Examples of the substituent include methyl group, ethyl group, propyl group, hydroxy group, hydroxyalkyl group, carboxy group, halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), an acyl group, an alkyloxycarbonyl group, an alkylcarbonyloxy group, and the like.

Specific examples of the condensed ring formed by Y _a01 ^x0 and W ¹ are shown below. W ^α represents a polymerizable group. ** indicates a bond with the group represented by formula (a0-n-1).

In the formula (a0-2), Y _a02 ^x0 is a single bond or a (n _a02 +1)-valent linking group. Y _a02 ^x0 is the same as the above-mentioned Ya ^x0 and Y _a01 ^x0 .

In the above formulas (a0-1) and (a0-2), n _a01 and n _a02 are integers of 1 to 3, preferably 1 or 2, more preferably 1.

The structural unit (a0) containing the partial structure represented by the general formula (a0-n-1) is mainly a polymerizable group at the W ¹ site in the compound represented by the following general formula (a0-1-1). More preferably, it is a structural unit (a0-1-1) converted into a chain.

［式中、Ｒ^１は炭素数１～１２のフッ素化アルキル基である。Ｒ^２はフッ素原子を有してもよい炭素数１～１２の有機基又は水素原子である。Ｗ^１は重合性基含有基である。Ｙ_ａ０１ ^ｘ１は単結合又は２価の連結基である。Ｙ_ａ０１ ^ｘ２は、置換基を有してもよい（ｎ_ａ０１＋１）価の芳香族炭化水素基である。Ｗ^１とＹ_ａ０１ ^ｘ１とは縮合環を形成していてもよく、Ｗ^１とＹ_ａ０１ ^ｘ１とＹ_ａ０１ ^ｘ２とで縮合環を形成していてもよい。ｎ_ａ０１は、１～３の整数である。］

[In the formula, R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms. R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. ^W1 is a polymerizable group-containing group. Y _a01 ^x1 is a single bond or a divalent linking group. Y _a01 ^x2 is a (n _a01 +1)-valent aromatic hydrocarbon group which may have a substituent. W ¹ and Y _a01 ^x1 may form a condensed ring, and W ¹ and Y _a01 ^x1 and Y _a01 ^x2 may form a condensed ring. n _a01 is an integer of 1-3. ]

In the above formula (a0-1-1), R ¹ and R ² are the same as described for (a0-n-1) above.

In the formula (a0-1-1), ^W1 is the same as described in (a0-1) and (a0-2) above.

In the above formula (a0-1-1), Y _a01 ^x1 is a single bond or a divalent linking group, which is the same as described for Ya ^x0 and Y _a01 ^x0 above.

In the formula (a0-1-1), Y _a01 ^x2 is a (n _a01 +1)-valent aromatic hydrocarbon group which may have a substituent.
Examples of the aromatic hydrocarbon group for Y _a01 ^x2 include groups obtained by removing (n _a01 +1) hydrogen atoms from an 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 monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

Examples of substituents that Y _a01 ^x2 may have include a carboxy group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), an alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), An alkyloxycarbonyl group and the like can be mentioned.

In the above formula (a0-1-1), W ¹ and Y _a01 ^x1 may form a condensed ring, and W ¹ and Y _a01 ^x1 and Y _a01 ^x2 may form a condensed ring. . The condensed ring formed by W ¹ and Y _a01 ^x1 and the condensed ring formed by W ¹ , Y _a01 ^x1 and Y _a01 ^x2 are formed by Y _a01 ^x0 and W ¹ in the above formula (a0-1). It is the same as the content explained for the condensed ring.

In the formula (a0-1-1), n _a01 is an integer of 1 to 3, preferably 1 or 2, more preferably 1.

Specific examples of the structural unit (a0) are shown below.
In the formula below, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

Among the above examples, the structural unit (a0) is preferably at least one selected from the group consisting of structural units represented by chemical formulas (a0-1-11) to (a0-1-18). Among these, the structural unit (a0) is at least selected from the group consisting of structural units having aromatic hydrocarbon groups and represented by chemical formulas (a0-1-12) and (a0-1-14). One is more preferred.

The structural unit (a0) contained in the component (A1) may be one type or two or more types.
The ratio of the structural unit (a0) in the component (A1) is preferably 10 to 80 mol%, preferably 10 to 65 mol%, relative to the total (100 mol%) of all structural units constituting the component (A1). is more preferred, and 10 to 50 mol % is particularly preferred.
By setting the ratio of the structural unit (a0) to the lower limit of the preferred range or more, the solubility in the developer and the adhesion to the substrate are improved. It becomes easier to balance with the constituent units of

≪Other structural units≫
The component (A1) may have structural units other than the structural unit (a0) described above.
Other structural units include, for example, a structural unit (a1) containing an acid-decomposable group whose polarity increases under the action of an acid, a lactone-containing cyclic group, a —SO ₂ —-containing cyclic group, or a carbonate-containing cyclic group. Structural unit (a2), structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group, structural unit (a9) represented by general formula (a9-1) described later, structural unit derived from styrene (a10 ), a structural unit (a4) containing an acid-nondissociable aliphatic cyclic group (excluding those corresponding to the structural unit (a1) or the structural unit (a2)), and the like.

<<Constituent unit (a1)>>
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases under the action of acid.
An "acid-decomposable group" is a group having acid-decomposability such that at least some of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid.
The acid-decomposable group whose polarity is increased by the action of an acid includes, for example, a group that is decomposed by the action of an acid to form a polar group.
Polar groups include, for example, a carboxy group, a hydroxyl group, an amino group, and a sulfo group (--SO ₃ H). Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferred, a carboxy group or a hydroxyl group is more preferred, and a carboxy group is particularly preferred.
More specifically, the acid-decomposable group includes a group in which the polar group is protected with an acid-labile group (for example, a group in which the hydrogen atom of the OH-containing polar group is protected with an acid-labile group).

The term "acid-dissociable group" as used herein means (i) a group having acid-dissociable properties in which the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved by the action of an acid; or (ii) after some bonds are cleaved by the action of an acid, decarboxylation further occurs to cleave the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group; It refers to both the group to obtain.
The acid-labile group that constitutes the acid-labile group must be a group with a lower polarity than the polar group generated by the dissociation of the acid-labile group, so that the acid-labile group can be decomposed by the action of an acid. When is dissociated, a polar group having a higher polarity than the acid-dissociable group is generated and the polarity is increased. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the solubility in the developer relatively changes. When the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility increases. Decrease.

Examples of acid-dissociable groups include those that have hitherto been proposed as acid-dissociable groups for base resins for chemically amplified resist compositions.
Specific examples of acid-dissociable groups proposed as base resins for chemically amplified resist compositions include "acetal-type acid-dissociable groups" and "tertiary alkyl ester-type acid-dissociable groups" described below. group" and "tertiary alkyloxycarbonyl acid dissociable group".

Acetal-type acid-labile group:
Examples of the acid-dissociable group protecting the carboxy group or hydroxyl group among the polar groups include acid-dissociable groups represented by the following general formula (a1-r-1) (hereinafter referred to as "acetal-type acid-dissociable groups" There is a thing.) is mentioned.

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

[In the formula, Ra' ¹ and Ra' ² are hydrogen atoms or alkyl groups. Ra' ³ is a hydrocarbon group, and Ra' ³ may combine with either Ra' ¹ or Ra' ² to form a ring. ]

In formula (a1-r-1), at least one of Ra' ¹ and Ra' ² is preferably a hydrogen atom, more preferably both are hydrogen atoms.
When Ra' ¹ or Ra' ² is an alkyl group, examples of the alkyl group include the alkyl groups exemplified as the substituents that may be bonded to the α-position carbon atom in the explanation of the α-substituted acrylic acid ester. The same groups can be mentioned, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups are preferred. More specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group, and a methyl group or an ethyl group is More preferred, and a methyl group is particularly preferred.

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

The branched chain alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

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

When the cyclic hydrocarbon group for Ra' ³ is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.
Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.
Specifically, the aromatic hydrocarbon group for Ra' ³ is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); A group obtained by removing one hydrogen atom from an aromatic compound containing (e.g., biphenyl, fluorene, etc.); , phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly 1. preferable.

The cyclic hydrocarbon group for Ra' ³ may have a substituent. Examples of this substituent include -R ^P1 , -R ^P2 -OR P1 , -R ^P2 -CO-R ^P1 , -R ^P2 -CO-OR ^P1 , -R ^{P2 -O} -CO-R ^P1 , -R ^P2 -OH, -R ^P2 -CN or -R ^P2 -COOH (hereinafter, these substituents are collectively referred to as "Ra ⁰⁵ "), and the like.
Here, R ^P1 is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic group having 6 to 30 carbon atoms. is a group hydrocarbon group. R ^P2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent divalent hydrocarbon group having 6 to 30 carbon atoms. is an aromatic hydrocarbon group. However, some or all of the hydrogen atoms of the chain saturated hydrocarbon groups, aliphatic cyclic saturated hydrocarbon groups and aromatic hydrocarbon groups of R ^P1 and R ^P2 may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the above substituents, or may have one or more of each of a plurality of the above substituents.
Examples of monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and decyl group. .
Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group and the like. Monocyclic aliphatic saturated hydrocarbon group; bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl group , tetracyclo[6.2.1.13,6.02,7]dodecanyl group and polycyclic aliphatic saturated hydrocarbon group such as adamantyl group.
Examples of monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

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

Tertiary alkyl ester type acid dissociable group:
Among the above polar groups, the acid-dissociable group protecting the carboxy group includes, for example, an acid-dissociable group represented by the following general formula (a1-r-2).
Among the acid-dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups may hereinafter be referred to as "tertiary alkyl ester-type acid-dissociable groups" for convenience. .

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

[In the formula, each of Ra' ⁴ to Ra' ⁶ is a hydrocarbon group, and Ra' ⁵ and Ra' ⁶ may combine with each other to form a ring. ]

The hydrocarbon group for ^Ra'4 includes a linear or branched alkyl group, a chain or cyclic alkenyl group, or a cyclic hydrocarbon group.
Linear or branched alkyl groups and cyclic hydrocarbon groups (monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, etc.) in Ra' ⁴ ) is the same as the above ^Ra'3 .
The chain or cyclic alkenyl group for ^Ra'4 is preferably an alkenyl group having 2 to 10 carbon atoms.
Examples of hydrocarbon groups for Ra' ⁵ and Ra' ⁶ include the same groups as those for Ra' ³ above.

When Ra' ⁵ and Ra' ⁶ are bonded to each other to form a ring, a group represented by the following general formula (a1-r2-1) or a group represented by the following general formula (a1-r2-2) and a group represented by the following general formula (a1-r2-3).
On the other hand, when Ra' ⁴ to Ra' ⁶ are not bonded to each other and are independent hydrocarbon groups, groups represented by the following general formula (a1-r2-4) are suitable.

［式（ａ１－ｒ２－１）中、Ｒａ’^１０は、炭素数１～１０のアルキル基、又は下記一般式（ａ１－ｒ２－ｒ１）で表される基を示す。Ｒａ’^１１はＲａ’^１０が結合した炭素原子と共に脂肪族環式基を形成する基を示す。式（ａ１－ｒ２－２）中、Ｙａは炭素原子である。Ｘａは、Ｙａと共に環状の炭化水素基を形成する基である。この環状の炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。Ｒａ^０１～Ｒａ^０３は、それぞれ独立して、水素原子、炭素数１～１０の１価の鎖状飽和炭化水素基又は炭素数３～２０の１価の脂肪族環状飽和炭化水素基である。この鎖状飽和炭化水素基及び脂肪族環状飽和炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。Ｒａ^０１～Ｒａ^０３の２つ以上が互いに結合して環状構造を形成していてもよい。式（ａ１－ｒ２－３）中、Ｙａａは炭素原子である。Ｘａａは、Ｙａａと共に脂肪族環式基を形成する基である。Ｒａ^０４は、置換基を有していてもよい芳香族炭化水素基である。式（ａ１－ｒ２－４）中、Ｒａ’^１２及びＲａ’^１３は、それぞれ独立に、炭素数１～１０の１価の鎖状飽和炭化水素基又は水素原子である。この鎖状飽和炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。Ｒａ’^１４は、置換基を有していてもよい芳香族炭化水素基である。＊は結合手を示す（以下同じ）。］

[In the formula (a1-r2-1), Ra′ ¹⁰ represents an alkyl group having 1 to 10 carbon atoms or a group represented by the following general formula (a1-r2-r1). Ra' ¹¹ represents a group that forms an aliphatic cyclic group together with the carbon atom to which Ra' ¹⁰ is attached. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms of this cyclic hydrocarbon group may be substituted. Ra ⁰¹ to Ra ⁰³ are each independently a hydrogen atom, a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group and aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra ⁰¹ to Ra ⁰³ may combine with each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra ⁰⁴ is an optionally substituted aromatic hydrocarbon group. In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms of this chain saturated hydrocarbon group may be substituted. Ra' ¹⁴ is an aromatic hydrocarbon group optionally having a substituent. * indicates a bond (same below). ]

［式中、Ｙａ^０は、第４級炭素原子である。Ｒａ^０３１、Ｒａ^０３２及びＲａ^０３３は、それぞれ独立に、置換基を有していてもよい炭化水素基である。但し、Ｒａ^０３１、Ｒａ^０３２及びＲａ^０３３のうちの１つ以上は、少なくとも一つの極性基を有する炭化水素基である。］

[In the formula, Ya ⁰ is a quaternary carbon atom. Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are each independently a hydrocarbon group optionally having a substituent. However, one or more of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least one polar group. ]

In the above formula (a1-r2-1), the alkyl group having 1 to 10 carbon atoms for Ra' ¹⁰ is the linear or branched alkyl group for Ra' ³ in formula (a1-r-1). The groups mentioned are preferred. Ra' ¹⁰ is preferably an alkyl group having 1 to 5 carbon atoms.

In the formula (a1-r2-r1), Ya ⁰ is a quaternary carbon atom. That is, there are four carbon atoms next to Ya ⁰ (carbon atom).

In the formula (a1-r2-r1), Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are each independently a hydrocarbon group which may have a substituent. The hydrocarbon groups for Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ each independently include a linear or branched alkyl group, a chain or cyclic alkenyl group, or a cyclic hydrocarbon group.

The linear alkyl group for Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group and the like. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.
The chain or cyclic alkenyl group for Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is preferably an alkenyl group having 2 to 10 carbon atoms.

The cyclic hydrocarbon group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically includes adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specifically, the aromatic hydrocarbon group includes a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); A group obtained by removing one hydrogen atom from a compound (e.g., biphenyl, fluorene, etc.); A group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., benzyl group, phenethyl group , 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

When the hydrocarbon groups represented by the above Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are substituted, the substituents include, for example, a hydroxy group, a carboxy group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc. ), alkoxy groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), alkyloxycarbonyl groups, and the like.

Among the above, the optionally substituted hydrocarbon group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is preferably an optionally substituted linear or branched alkyl group, A straight-chain alkyl group is more preferred.

However, one or more of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least a polar group.
The term “hydrocarbon group having a polar group” means a hydrocarbon group in which a methylene group (—CH ₂ —) constituting the hydrocarbon group is substituted with a polar group, or at least one hydrogen atom constituting the hydrocarbon group is Any one substituted on a polar group is included.
As such a “hydrocarbon group having a polar group”, a functional group represented by the following general formula (a1-p1) is preferable.

［式中、Ｒａ^０７は、炭素数２～１２の２価の炭化水素基を表す。Ｒａ^０８は、ヘテロ原子を含む２価の連結基を表す。Ｒａ^０６は、炭素数１～１２の１価の炭化水素基を表す。ｎ_ｐ０は、１～６の整数である。］

[In the formula, Ra ⁰⁷ represents a divalent hydrocarbon group having 2 to 12 carbon atoms. Ra ⁰⁸ represents a divalent linking group containing a heteroatom. Ra ⁰⁶ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms. n _p0 is an integer from 1-6. ]

In the formula (a1-p1), Ra ⁰⁷ represents a divalent hydrocarbon group having 2 to 12 carbon atoms.
Ra ⁰⁷ has 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 2 carbon atoms.
The hydrocarbon group for Ra ⁰⁷ is preferably a chain or cyclic aliphatic hydrocarbon group, more preferably a chain hydrocarbon group.
Examples of Ra ⁰⁷ include ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1, 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, etc. linear alkanediyl group; propane-1,2-diyl group, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, pentane-1,4-diyl group, 2 -branched alkanediyl groups such as methylbutane-1,4-diyl; cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, cyclooctane-1 Cycloalkanediyl groups such as ,5-diyl group; A cyclic divalent alicyclic hydrocarbon group and the like are included.
Among the above, an alkanediyl group is preferred, and a linear alkanediyl group is more preferred.

In the above formula (a1-p1), Ra ⁰⁸ represents a divalent linking group containing a heteroatom.
Examples of Ra ⁰⁸ include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH- , -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O) ₂ -, - and S(=O) ₂ -O-.
Among these, -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O- are preferred from the viewpoint of solubility in the developer, and - O- and -C(=O)- are particularly preferred.

In the formula (a1-p1), Ra ⁰⁶ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms.
Ra ⁰⁶ has 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, even more preferably 1 to 3 carbon atoms, from the viewpoint of solubility in a developer. 1 or 2 are particularly preferred, and 1 is most preferred.

The hydrocarbon group for Ra ⁰⁶ may be a chain hydrocarbon group, a cyclic hydrocarbon group, or a hydrocarbon group combining a chain and a cyclic hydrocarbon group.
Chain hydrocarbon groups include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n -heptyl group, 2-ethylhexyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group and the like.

The cyclic hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methyl Cycloalkyl groups such as cyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group and cyclodecyl group can be mentioned. Polycyclic alicyclic hydrocarbon groups include, for example, decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1-(adamantan-1-yl)alkane-1-yl group, norbornyl group, methylnorbornyl group, isobornyl group, and the like.
Examples of aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl and mesityl groups. , biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and the like.

From the viewpoint of solubility in a developer, Ra ⁰⁶ is preferably a chain hydrocarbon group, more preferably an alkyl group, and still more preferably a linear alkyl group.

In the formula (a1-p1), n _p0 is an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1 or 2, and still more preferably 1.

Specific examples of the hydrocarbon group having at least a polar group are shown below.
In the following formulas, * is a bond that binds to the quaternary carbon atom (Ya ⁰ ).

In the above formula (a1-r2-r1), among Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ , the number of hydrocarbon groups having at least a polar group is one or more. For example, one or two of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are preferable, and one is particularly preferable.

The hydrocarbon group having at least the polar group may have a substituent other than the polar group. Examples of this substituent include halogen atoms (fluorine atom, chlorine atom, bromine atom, etc.) and halogenated alkyl groups having 1 to 5 carbon atoms.

In formula (a1-r2-1), Ra' ¹¹ (the aliphatic cyclic group formed with the carbon atom to which Ra' ¹⁰ is bonded) is the monocyclic group of Ra' ³ in formula (a1-r-1) or the group exemplified as the aliphatic hydrocarbon group which is a polycyclic group.

In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes a cyclic ^monovalent hydrocarbon group (aliphatic (hydrocarbon group) from which one or more hydrogen atoms have been further removed.
The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of this substituent include those similar to the substituents that the cyclic hydrocarbon group in the above Ra' ³ may have.
In formula (a1-r2-2), the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra ⁰¹ to Ra ⁰³ includes, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group and the like.
Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms in Ra ⁰¹ to Ra ⁰³ include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and cyclodecyl. monocyclic aliphatic saturated hydrocarbon groups such as cyclododecyl group; bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1 .13,7]decanyl group, tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and polycyclic aliphatic saturated hydrocarbon groups such as adamantyl group.
Among them, Ra ⁰¹ to Ra ⁰³ are preferably a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, from the viewpoint of facilitating the synthesis of the monomer compound from which the structural unit (a1) is derived. Among them, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

Examples of substituents possessed by the chain saturated hydrocarbon groups or aliphatic cyclic saturated hydrocarbon groups represented by Ra ⁰¹ to Ra ⁰³ include the same groups as those for Ra ⁰⁵ above.

Examples of the group containing a carbon-carbon double bond produced by forming a cyclic structure by bonding two or more of Ra ⁰¹ to Ra ⁰³ to each other include, for example, a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methyl A cyclohexenyl group, a cyclopentylideneethenyl group, a cyclohexylideneethenyl group and the like can be mentioned. Among these, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylideneethenyl group are preferred from the viewpoint of ease of synthesis of the monomer compound from which the structural unit (a1) is derived.

In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is a monocyclic group or polycyclic group of Ra' ³ in formula (a1-r-1). The groups mentioned as hydrogen groups are preferred.
In formula (a1-r2-3), examples of the aromatic hydrocarbon group for Ra ⁰⁴ include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra ⁰⁴ is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene. A group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene is more preferable, a group obtained by removing one or more hydrogen atoms from benzene or naphthalene is particularly preferable, and a group obtained by removing one or more hydrogen atoms from benzene is most preferable. preferable.

Examples of substituents that Ra ⁰⁴ in formula (a1-r2-3) may have include methyl group, ethyl group, propyl group, hydroxyl group, carboxyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), alkoxy groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), alkyloxycarbonyl groups, and the like.

In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. The monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms for Ra' ¹² and Ra' ¹³ includes the monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms for Ra ⁰¹ to Ra ⁰³ above. The same as the group can be mentioned. Some or all of the hydrogen atoms of this chain saturated hydrocarbon group may be substituted.
Ra' ¹² and Ra' ¹³ are preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group, and particularly a methyl group. preferable.
When the chain saturated hydrocarbon groups represented by Ra' ¹² and Ra' ¹³ are substituted, examples of the substituent include groups similar to those of Ra ⁰⁵ above.

In formula (a1-r2-4), Ra' ¹⁴ is an aromatic hydrocarbon group which may have a substituent. Examples of the aromatic hydrocarbon group for ^Ra'14 include those similar to the aromatic hydrocarbon group for ^Ra04 . Among them, Ra' ¹⁴ is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, and more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene. Preferably, a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene is more preferred, a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene is particularly preferred, and a group obtained by removing one or more hydrogen atoms from naphthalene is Most preferred.
Examples of the substituent that Ra' ¹⁴ may have include the same substituents that Ra ⁰⁴ may have.

When Ra' ¹⁴ in formula (a1-r2-4) is a naphthyl group, the position bonding to the tertiary carbon atom in formula (a1-r2-4) is the 1- or 2-position of the naphthyl group. Either can be used.
When Ra' ¹⁴ in formula (a1-r2-4) is an anthryl group, the position bonding to the tertiary carbon atom in formula (a1-r2-4) is the 1-position, 2-position, or Any of the ninth positions may be used.

Specific examples of the group represented by the formula (a1-r2-1) are shown below.

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

Specific examples of the group represented by the formula (a1-r2-3) are shown below.

Specific examples of the group represented by the formula (a1-r2-4) are shown below.

Tertiary alkyloxycarbonyl acid dissociable group:
Among the polar groups, the acid-dissociable group that protects the hydroxyl group includes, for example, an acid-dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as "tertiary alkyloxycarbonyl acid-dissociable group ) can be mentioned.

［式中、Ｒａ’^７～Ｒａ’^９はそれぞれアルキル基である。］

[In the formula, each of Ra' ⁷ to Ra' ⁹ is an alkyl group. ]

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

As the structural unit (a1), a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, a structural unit derived from acrylamide, hydroxystyrene or hydroxy - of structural units derived from vinyl benzoic acid or vinyl benzoic acid derivatives, wherein at least part of the hydrogen atoms in the hydroxyl groups of structural units derived from styrene derivatives are protected by substituents containing the acid-decomposable groups Structural units in which at least part of the hydrogen atoms in C(=O)--OH are protected by a substituent containing the acid-decomposable group are exemplified.

As the structural unit (a1), among the above, a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent is preferable.
Preferred specific examples of such a structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2).

［式中、Ｒは、水素原子、炭素数１～５のアルキル基又は炭素数１～５のハロゲン化アルキル基である。Ｖａ^１は、エーテル結合を有していてもよい２価の炭化水素基である。ｎ_ａ１は、０～２の整数である。Ｒａ^１は、上記の一般式（ａ１－ｒ－１）又は（ａ１－ｒ－２）で表される酸解離性基である。Ｗａ^１はｎ_ａ２＋１価の炭化水素基であり、ｎ_ａ２は１～３の整数であり、Ｒａ^２は上記の一般式（ａ１－ｒ－１）又は（ａ１－ｒ－３）で表される酸解離性基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group optionally having an ether bond. n _a1 is an integer of 0-2. Ra ¹ is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-2). Wa ¹ is an n _a2 + monovalent hydrocarbon group, n _a2 is an integer of 1 to 3, and Ra ² is represented by the above general formula (a1-r-1) or (a1-r-3) It is an acid dissociable group. ]

In the above formula (a1-1), the alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group or an ethyl group. , propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferred.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group in view of industrial availability.

In formula (a1-1), the divalent hydrocarbon group in Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specifically, the aliphatic hydrocarbon group includes a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, and the like.

The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. .
As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specifically, a methylene group [ _--CH.sub.2-- ], an ethylene group [--( _CH.sub.2 ) _.sub.2-- ], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -] and the like.
The branched chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) _2- , -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups;- 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 Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ - and -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples 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 aliphatic hydrocarbon group containing a ring in the structure includes an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group intervenes in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. 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 include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group as the divalent hydrocarbon group for Va ¹ is a hydrocarbon group having an aromatic ring.
Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most 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 aromatic rings possessed by aromatic hydrocarbon groups include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; Atom-substituted heteroaromatic rings and the like are included. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like.
Specifically, the aromatic hydrocarbon group includes a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group ) in which one of the hydrogen atoms is substituted with an alkylene group (e.g., benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl such as 2-naphthylethyl group group obtained by removing one hydrogen atom from the aryl group in the group), and the like. The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

In the above formula (a1-1), Ra ¹ is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

In the formula (a1-2), the n _a2 +1 valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated, and usually preferably saturated. As the aliphatic hydrocarbon group, a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a linear or branched aliphatic hydrocarbon group Groups combined with an aliphatic hydrocarbon group containing a ring in the structure can be mentioned.
The n _a2 +1 valence is preferably 2 to 4 valences, more preferably 2 or 3 valences.

In formula (a1-2), Ra ² is an acid dissociable group represented by general formula (a1-r-1) or (a1-r-3) above.

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

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

The structural unit (a1) contained in the component (A1) may be one type or two or more types.
As the structural unit (a1), the structural unit represented by the above formula (a1-1) is more preferable because the properties (sensitivity, shape, etc.) in electron beam or EUV lithography can be more easily improved.
Among these, as the structural unit (a1), one containing a structural unit represented by the following general formula (a1-1-1) is particularly preferable.

［式中、Ｒａ^１”は、一般式（ａ１－ｒ２－１）、（ａ１－ｒ２－３）又は（ａ１－ｒ２－４）で表される酸解離性基である。］

[Wherein, Ra ¹ ″ is an acid dissociable group represented by general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4).]

In formula (a1-1-1), R, Va ¹ and n _a1 are the same as R, Va ¹ and n _a1 in formula (a1-1).
The explanation of the acid dissociable group represented by general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4) is as described above.

The ratio of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol%, preferably 10 to 75 mol%, relative to the total (100 mol%) of all structural units constituting the component (A1). More preferably, 30 to 70 mol % is even more preferable.
By setting the ratio of the structural unit (a1) to the lower limit or more, lithography properties such as sensitivity, resolution, and improvement of roughness are improved. Also, by setting the content to the upper limit or less, it is possible to balance with other structural units, and various lithography properties are improved.

<<Structural Unit (a10) Containing a Hydroxystyrene Skeleton>>
The component (A1) preferably has a structural unit (a10) containing a hydroxystyrene skeleton in addition to the structural unit (a1).
As such a structural unit (a10), for example, a structural unit represented by the following general formula (a10-1) is suitable.

［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^ｘ１は、単結合又は２価の連結基である。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 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or a divalent linking group. Wa ^x1 is a (n _ax1 +1) valent aromatic hydrocarbon group. n _ax1 is an integer of 1-3. ]

In formula (a10-1) above, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, 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. The halogenated alkyl group having 1 to 5 carbon atoms for R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferred.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group in view of industrial availability.

In the formula (a10-1), Ya ^x1 is a single bond or a divalent linking group.
The divalent linking group for Ya ^x1 is the same as described for Ya ^x0 above.

In the formula (a10-1), Wa ^x1 is a (n _ax1 +1)-valent aromatic hydrocarbon group.
Examples of the aromatic hydrocarbon group for Wa ^x1 include groups obtained by removing (n _ax1 +1) hydrogen atoms from an 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 monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

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

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

The structural unit (a10) contained in the component (A1) may be one type or two or more types.
The ratio of the structural unit (a10) in the component (A1) is, for example, 0 to 80 mol%, 10 to 80%, relative to the total (100 mol%) of all structural units constituting the component (A1). mol % is preferred, 20 to 70 mol % is more preferred, and 30 to 60 mol % is particularly preferred.
By adjusting the ratio of the structural unit (a10) to the lower limit of the preferable range or more, lithography properties such as sensitivity, resolution, or improvement of roughness are improved. Also, by setting the content to the upper limit or less, it is possible to balance with other structural units, and various lithography properties are improved.

<<Constituent unit (a2)>>
In addition to the structural unit (a1), the component (A1) further comprises a structural unit (a2) containing a lactone-containing cyclic group, a —SO ₂ —-containing cyclic group or a carbonate-containing cyclic group (with the proviso that the structural unit ( a1) is preferable.
The lactone-containing cyclic group, —SO ₂ —-containing cyclic group, or carbonate-containing cyclic group of the structural unit (a2) contributes to the adhesion of the resist film to the substrate when the component (A1) is used to form the resist film. It is an effective one in terms of enhancing sexuality. Further, by having the structural unit (a2), for example, effects such as appropriately adjusting the acid diffusion length, increasing the adhesion of the resist film to the substrate, or appropriately adjusting the solubility during development, Lithography properties and the like are improved.

A “lactone-containing cyclic group” refers to a cyclic group containing a ring containing —O—C(=O)— in its ring skeleton (lactone ring). A lactone ring is counted as the first ring, and a group containing only a lactone ring is called a monocyclic group, and a group containing other ring structures is called a polycyclic group regardless of the structure. A lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
Any lactone-containing cyclic group in the structural unit (a2) can be used without particular limitation. Specific examples include groups represented by general formulas (a2-r-1) to (a2-r-7) below.

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

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

In the general formulas (a2-r-1) to (a2-r-7), the alkyl group for Ra' ²¹ is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and hexyl group. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred.
As the alkoxy group for Ra' ²¹ , an alkoxy group having 1 to 6 carbon atoms is preferable. The alkoxy group is preferably linear or branched. Specific examples include groups in which the alkyl group exemplified as the alkyl group for Ra' ²¹ and an oxygen atom (--O--) are linked.
The halogen atom for Ra' ²¹ includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferred.
Examples of the halogenated alkyl group for Ra' ²¹ include groups in which part or all of the hydrogen atoms of the alkyl group for Ra' ²¹ are substituted with the above-described halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In -COOR'' and -OC(=O)R'' in Ra' ²¹ , R'' is either a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO ₂ -containing cyclic group. is.
The alkyl group for R″ may be linear, branched or cyclic, and preferably has 1 to 15 carbon atoms.
When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. or a group obtained by removing one or more hydrogen atoms from monocycloalkane which may or may not be substituted with a fluorinated alkyl group; polycycloalkane such as bicycloalkane, tricycloalkane and tetracycloalkane Examples include groups obtained by removing one or more hydrogen atoms from, etc. More specifically, groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; Examples include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as cyclodecane and tetracyclododecane.
Examples of the lactone-containing cyclic group for R″ include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7).
The carbonate-containing cyclic group in R" is the same as the carbonate-containing cyclic group described later, and specifically groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. is mentioned.
The —SO ₂ -containing cyclic group in R″ is the same as the —SO ₂ -containing cyclic group described later, and specifically, general formulas (a5-r-1) to (a5-r-4) The group represented respectively by is mentioned.
The hydroxyalkyl group for Ra' ²¹ preferably has 1 to 6 carbon atoms, and specific examples include groups in which at least one hydrogen atom of the alkyl group for Ra' ²¹ is substituted with a hydroxyl group. .

In the general formulas (a2-r-2), (a2-r-3) and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A″ is a linear or branched An alkylene group is preferred, and includes a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples include the terminal of the alkylene group or the carbon Groups having -O- or -S- interposed between atoms, such as -O-CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH _A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

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

“—SO ₂ —containing cyclic group” refers to a cyclic group containing a ring containing —SO ₂ — in its ring skeleton, and specifically, the sulfur atom (S) in —SO ₂ — is A cyclic group that forms part of the ring skeleton of a cyclic group. A ring containing —SO ₂ — in its ring skeleton is counted as the first ring, and if it contains only this ring, it is a monocyclic group, and if it has another ring structure, it is a polycyclic group regardless of its structure. called. The —SO ₂ —containing cyclic group may be a monocyclic group or a polycyclic group.
A —SO ₂ —containing cyclic group is particularly a cyclic group containing —O—SO ₂ — in its ring skeleton, ie, —O—S— in —O—SO ₂ — forms part of the ring skeleton. Preferred are cyclic groups containing a forming sultone ring.
More specific examples of the —SO ₂ —containing cyclic group include groups represented by general formulas (a5-r-1) to (a5-r-4) below.

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

[In the formula, each Ra' ⁵¹ is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group or a cyano group; Yes; R″ is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO ₂ —-containing cyclic group; A″ is a carbon optionally containing an oxygen atom or a sulfur atom It is an alkylene group of numbers 1-5, an oxygen atom or a sulfur atom, and n' is an integer of 0-2. ]

In the general formulas (a5-r-1) to (a5-r-2), A″ is the general formulas (a2-r-2), (a2-r-3), (a2-r-5) It is the same as A” in the middle.
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group in Ra' ⁵¹ are represented by the general formulas (a2-r-1) to ( Examples are the same as those mentioned in the description of Ra' ²¹ in a2-r-7).
Specific examples of groups represented by general formulas (a5-r-1) to (a5-r-4) are shown below. "Ac" in the formula represents an acetyl group.

A “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C(═O)—O— in its ring skeleton. The carbonate ring is counted as the first ring, and the group containing only the carbonate ring is called a monocyclic group, and the group containing other ring structures is called a polycyclic group regardless of the structure. A carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
Any carbonate ring-containing cyclic group can be used without particular limitation. Specific examples include groups represented by general formulas (ax3-r-1) to (ax3-r-3) below.

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

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

In the general formulas (ax3-r-2) to (ax3-r-3), A″ is the general formulas (a2-r-2), (a2-r-3), (a2-r-5) It is the same as A” in the middle.
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group in Ra' ³¹ are represented by the general formulas (a2-r-1) to ( Examples are the same as those mentioned in the description of Ra' ²¹ in a2-r-7).
Specific examples of groups represented by general formulas (ax3-r-1) to (ax3-r-3) are shown below.

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

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

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ²¹ is a single bond or a divalent linking group. La ²¹ is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, and R' represents a hydrogen atom or a methyl group. However, when La ²¹ is -O-, Ya ²¹ is not -CO-. Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO ₂ —-containing cyclic group. ]

In formula (a2-1), R is the same as defined above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and is particularly preferably a hydrogen atom or a methyl group in terms of industrial availability.

In formula (a2-1), R is the same as defined above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and is particularly preferably a hydrogen atom or a methyl group in terms of industrial availability.

In formula (a2-1), the divalent linking group for Ya ²¹ is the same as described for Ya ^x0 above.
Ya ²¹ is preferably a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof. .

In formula (a2-1) above, Ra ²¹ is a lactone-containing cyclic group, —SO ₂ —-containing cyclic group or carbonate-containing cyclic group.
The lactone-containing cyclic group, —SO ₂ —-containing cyclic group, and carbonate-containing cyclic group for Ra ²¹ are represented by the above-described general formulas (a2-r-1) to (a2-r-7), respectively. groups, groups represented by general formulas (a5-r-1) to (a5-r-4), groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively are preferably mentioned.
Among them, a lactone-containing cyclic group or a —SO ₂ —-containing cyclic group is preferable, and the general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r -1) are more preferred. Specifically, the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r- Any group represented by lc-6-1), (r-sl-1-1) and (r-sl-1-18) is more preferred.

The structural unit (a2) contained in the component (A1) may be one type or two or more types.
When the component (A1) has a structural unit (a2), the ratio of the structural unit (a2) is 1 to 50 mol% with respect to the total (100 mol%) of all structural units constituting the component (A1). is preferably 5 to 45 mol %, more preferably 10 to 40 mol %, and particularly preferably 10 to 30 mol %.
By setting the ratio of the structural unit (a2) to the preferable lower limit or more, the above-described effects can be sufficiently obtained by containing the structural unit (a2). A balance can be achieved with the unit, and various lithographic properties are improved.

<<Structural unit (a3)>>
In addition to the structural unit (a1), the component (A1) further includes a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group (provided that the structural unit (a1) and the structural unit (a2) are ) is preferred. By having the structural unit (a3) in the component (A1), the hydrophilicity of the component (A) increases, contributing to improvement in resolution. Also, the acid diffusion length can be adjusted appropriately.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a portion of the hydrogen atoms of an alkyl group are substituted with fluorine atoms, and the like, with the hydroxyl group being particularly preferred.
Examples of the aliphatic hydrocarbon group include linear or branched hydrocarbon groups (preferably alkylene groups) having 1 to 10 carbon atoms and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be either a monocyclic group or a polycyclic group, and can be appropriately selected from a number of groups proposed for use in resins for ArF excimer laser resist compositions, for example. The cyclic group is preferably a polycyclic group, more preferably having 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which a portion of the hydrogen atoms of the alkyl group is substituted with fluorine atoms is more preferred. Examples of the polycyclic group include groups obtained by removing two or more hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, and the like. Specific examples include groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, a group obtained by removing two or more hydrogen atoms from adamantane, a group obtained by removing two or more hydrogen atoms from norbornane, and a group obtained by removing two or more hydrogen atoms from tetracyclododecane Industrially preferred.

Any structural unit (a3) can be used without particular limitation as long as it contains a polar group-containing aliphatic hydrocarbon group.
The structural unit (a3) is a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent and includes a polar group-containing aliphatic hydrocarbon group. A building block is preferred.
As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, it is derived from hydroxyethyl ester of acrylic acid. are preferred.
Further, as the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), -2) and structural units represented by formula (a3-3) are preferred.

［式中、Ｒは前記と同じであり、ｊは１～３の整数であり、ｋは１～３の整数であり、ｔ’は１～３の整数であり、ｌは１～５の整数であり、ｓは１～３の整数である。］

[Wherein, R is the same as the above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, l is an integer of 1 to 5 and s is an integer from 1 to 3. ]

In formula (a3-1), j is preferably 1 or 2, more preferably 1. When j is 2, hydroxyl groups are preferably bonded to the 3- and 5-positions of the adamantyl group. When j is 1, a hydroxyl group is preferably bonded to the 3-position of the adamantyl group.
j is preferably 1, and particularly preferably a hydroxyl group is bonded to the 3-position of the adamantyl group.

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

In formula (a3-3), t' is preferably 1. l is preferably one. Preferably, s is 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to the terminal of the carboxyl group of acrylic acid. The fluorinated alkyl alcohol is preferably attached to the 5- or 6-position of the norbornyl group.

The structural unit (a3) contained in the component (A1) may be of one type or two or more types.
When the component (A1) has a structural unit (a3), it is preferably 1 to 40 mol%, more preferably 2 to 30 mol%, based on the total of all structural units constituting the component (A1). 5 to 25 mol % is more preferred, and 5 to 20 mol % is particularly preferred.
By setting the ratio of the structural unit (a3) to a preferable lower limit or more, the effect of containing the structural unit (a3) can be sufficiently obtained, while by setting the ratio to a preferable upper limit or less, it is possible to are easily balanced, and various lithographic properties are improved.

≪Other structural units≫
The component (A1) may have structural units other than the structural unit (a1), the structural unit (a10), the structural unit (a2), and the structural unit (a3) described above.
Other structural units include, for example, a structural unit (a9) represented by the general formula (a9-1) described later, a structural unit derived from styrene, a structural unit derived from a styrene derivative (provided that the structural unit (a10 ) except those corresponding to ), structural units containing an acid non-dissociable aliphatic cyclic group, and the like.

Structural unit (a9):
The structural unit (a9) is a structural unit represented by general formula (a9-1) below.

［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^９１は、単結合又は２価の連結基である。Ｙａ^９２は、２価の連結基である。Ｒ^９１は、置換基を有していてもよい炭化水素基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ⁹¹ is a single bond or a divalent linking group. Ya ⁹² is a divalent linking group. R ⁹¹ is a hydrocarbon group optionally having a substituent. ]

In formula (a9-1), R is the same as defined above.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and is particularly preferably a hydrogen atom or a methyl group in terms of industrial availability.

In formula (a9-1), the divalent linking group for Ya ⁹¹ is the same as described for Ya ^x0 above. Among them, Ya ⁹¹ is preferably a single bond.

In formula (a9-1), the divalent linking group in Ya ⁹² is the same as described for Ya ^x0 above.
In the divalent linking group for Ya ⁹² , the divalent hydrocarbon group which may have a substituent is preferably a linear or branched aliphatic hydrocarbon group.
In the divalent linking group for Ya ⁹² , the divalent linking group containing a hetero atom includes -O-, -C(=O)-O-, -C(=O)-, -OC (=O) -O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group .), -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, -C(=S)-, general 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 - or -Y a group represented by ²¹ -OC(=O)-Y ²² - [wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group optionally having a substituent; O is an oxygen atom and m' is an integer of 0-3. ] and the like. Of these, -C(=O)- and -C(=S)- are preferred.

In the above formula (a9-1), the hydrocarbon group for R ⁹¹ includes an alkyl group, a monovalent alicyclic hydrocarbon group, an aryl group, an aralkyl group and the like.
The alkyl group for R ⁹¹ preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and may be linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group and the like are preferred.
The monovalent alicyclic hydrocarbon group for R ⁹¹ preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms, and may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclobutane, cyclopentane, cyclohexane and the like. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms. adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
The aryl group for R ⁹¹ preferably has 6 to 18 carbon atoms, more preferably 6 to 10 carbon atoms, and more preferably a phenyl group.
The aralkyl group for R ⁹¹ is preferably an aralkyl group in which an alkylene group having 1 to 8 carbon atoms and the above “aryl group for R ⁹¹ ” are bonded, and an alkylene group having 1 to 6 carbon atoms and the above “aryl group for R ⁹¹ is more preferable, and an aralkyl group in which an alkylene group having 1 to 4 carbon atoms is bonded to the above-mentioned "aryl group for R ⁹¹ " is particularly preferable.
The hydrocarbon group for R ⁹¹ is preferably partially or entirely substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms in the hydrocarbon group are substituted with fluorine atoms. more preferably. Among them, a perfluoroalkyl group in which all the hydrogen atoms of the alkyl group described above are substituted with fluorine atoms is particularly preferable.

The hydrocarbon group for R ⁹¹ may have a substituent. Examples of such substituents include halogen atoms, oxo groups (=O), hydroxyl groups (-OH), amino groups (-NH ₂ ), and -SO ₂ -NH ₂ . Also, some of the carbon atoms constituting the hydrocarbon group may be substituted with a heteroatom-containing substituent. The heteroatom-containing substituents include -O-, -NH-, -N=, -C(=O)-O-, -S-, -S(=O) ₂ -, -S(=O ) ₂ —O—.
Examples of substituted hydrocarbon groups for R ⁹¹ include lactone-containing cyclic groups represented by the above general formulas (a2-r-1) to (a2-r-7).

Further, in R ⁹¹ , the hydrocarbon group having a substituent includes —SO ₂ —containing cyclic groups represented by the above general formulas (a5-r-1) to (a5-r-4), respectively; Also included are substituted aryl groups represented by chemical formulas, monovalent heterocyclic groups, and the like.

Among the structural units (a9), structural units represented by the following general formula (a9-1-1) are preferred.

［式中、Ｒは前記と同様であり、Ｙａ^９１は単結合または２価の連結基であり、Ｒ^９１は置換基を有していてもよい炭化水素基であり、Ｒ^９２は酸素原子又は硫黄原子である。］

[Wherein, R is the same as defined above, Ya ⁹¹ is a single bond or a divalent linking group, R ⁹¹ is an optionally substituted hydrocarbon group, R ⁹² is an oxygen atom or It is a sulfur atom. ]

The description of Ya ⁹¹ , R ⁹¹ and R in general formula (a9-1-1) is the same as above. Also, R ⁹² is an oxygen atom or a sulfur atom.

Specific examples of structural units represented by formula (a9-1) or general formula (a9-1-1) are shown below. In the formula below, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a9) contained in the component (A1) may be one type or two or more types.
When the component (A1) has the structural unit (a9), the ratio of the structural unit (a9) is 1 to 40 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). is preferably 3 to 30 mol %, more preferably 5 to 25 mol %, and particularly preferably 10 to 20 mol %.
By setting the ratio of the structural unit (a9) to the lower limit or more, for example, the acid diffusion length is appropriately adjusted, the adhesion of the resist film to the substrate is enhanced, the solubility during development is appropriately adjusted, or Effects such as improvement in etching resistance can be obtained, and by setting the content to the upper limit or less, a balance with other structural units can be achieved, and various lithography properties can be improved.

The component (A1) contained in the resist composition may be used alone or in combination of two or more.
In the resist composition of the present embodiment, the resin component which is the (A1) component has the structural unit (a0), and one type of polymer may be used alone, or two or more types may be used in combination. good too.
For example, the (A1) component includes a copolymer having a structural unit (a0) and optionally other structural units (hereinafter, this copolymer is referred to as "(A1-1) component"). It is preferably mentioned.

Preferred component (A1-1) includes, for example, a polymer compound having a repeating structure of the structural unit (a0) and the structural unit (a1), and a repeating structure of the structural unit (a0) and the structural unit (a2). A polymer compound, a polymer compound having a repeating structure of the structural unit (a0), the structural unit (a10), and other structural units, and a repeating structure of the structural unit (a0), the structural unit (a1), and the structural unit (a2) and a polymer compound having a repeating structure of the structural unit (a0), the structural unit (a1) and the structural unit (a10).
As the other structural unit, the structural unit (a1) is preferred, and a combination of the structural units (a1) and (a10) or the structural units (a1) and (a2) is more preferred.

Such component (A1) is obtained by dissolving a monomer that induces each structural unit in a polymerization solvent, and adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (for example, V-601, etc.) to the polymerization solvent. It can be produced by adding an agent and polymerizing. Alternatively, such component (A1) is obtained by dissolving a precursor monomer that induces the structural unit (a0) and, if necessary, a monomer that induces other structural units in a polymerization solvent, and It can be produced by adding a radical polymerization initiator, polymerizing, and then performing a deprotection reaction.

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, and is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and 3,000 to 20,000 is more preferred.
When the Mw of the component (A1) is less than the preferable upper limit of this range, it has sufficient solubility in a resist solvent for use as a resist, and when it is more than the preferable lower limit of this range, it has dry etching resistance and The cross-sectional shape of the resist pattern is good.
The dispersity (Mw/Mn) of component (A1) is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.1 to 2.0. . In addition, Mn shows a number average molecular weight.

Regarding the (A2) component The resist composition of the present embodiment includes, as the (A) component, a base component that does not correspond to the (A1) component and whose solubility in a developer changes due to the action of an acid (hereinafter referred to as "(A2 ) component”) may be used in combination.
The component (A2) is not particularly limited, and may be used by arbitrarily selecting from many conventionally known base components for chemically amplified resist compositions.
As the component (A2), one type of high-molecular compound or low-molecular compound may be used alone, or two or more types may be used in combination.

The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, still more preferably 75% by mass or more, and 100% by mass, relative to the total mass of component (A). may be When the proportion is 25% by mass or more, a resist pattern having excellent various lithography properties such as high sensitivity, resolution, and improvement in roughness can be easily formed. Such an effect is particularly remarkable in lithography using an electron beam or EUV.

The content of component (A) in the resist composition of the present embodiment may be adjusted according to the resist film thickness to be formed.

<Compound (BD1)>
In the resist composition of this embodiment, the (BD1) component is a compound composed of an anion moiety and a cation moiety represented by the following general formula (bd1).

［式中、Ｒｘ^１～Ｒｘ^４は、それぞれ独立に、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は２個以上が相互に結合して環構造を形成していてもよい。Ｒｙ^１～Ｒｙ^２は、それぞれ独立に、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は相互に結合して環構造を形成していてもよい。

は二重結合又は単結合である。Ｒｚ^１～Ｒｚ^４は、それぞれ独立に、原子価が許容する場合、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は２個以上が相互に結合して環構造を形成していてもよい。但し、Ｒｘ^１～Ｒｘ^４、Ｒｙ^１～Ｒｙ^２及びＲｚ^１～Ｒｚ^４のうち少なくとも１個はアニオン基を有し、アニオン部全体でｎ価のアニオンとなる。ｎは１以上の整数である。ｍは１以上の整数であって、Ｍ^ｍ＋は、ｍ価の有機カチオンを表す。］

[In the formula, Rx ¹ to Rx ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or two or more of them combine to form a ring structure; good too. Ry ¹ to Ry ² each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure.

is a double bond or a single bond. Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have However, at least one of Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the entire anion part becomes an n-valent anion. n is an integer of 1 or more. m is an integer of 1 or more, and M ^m+ represents an m-valent organic cation. ]

- About the anion portion In the formula (bd1), Rx ¹ to Rx ⁴ each independently represent a hydrocarbon group which may have a substituent or a hydrogen atom, or two or more of them are mutually bonded A ring structure may be formed.
Ry ¹ to Ry ² each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure.
Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have

The hydrocarbon groups in Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ may each be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a cyclic hydrocarbon group, or a chain may be a hydrocarbon group.
For example, the optionally substituted hydrocarbon groups in Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ include cyclic groups optionally having substituents and substituents. A chain alkyl group which may have a chain, or a chain alkenyl group which may have a substituent may be mentioned.

Cyclic group optionally having a substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group without aromaticity. Also, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. The cyclic hydrocarbon groups in Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ may contain heteroatoms such as heterocycles.

The aromatic hydrocarbon groups in Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ are hydrocarbon groups having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and particularly preferably 6 to 15 carbon atoms, 6 to 12 carbon atoms are most preferred. However, the number of carbon atoms does not include the number of carbon atoms in the substituent.
Specific examples of aromatic rings possessed by aromatic hydrocarbon groups in Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic rings thereof. and aromatic heterocycles in which some of the carbon atoms constituting are substituted with hetero atoms. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like.
Specific examples of aromatic hydrocarbon groups for Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ include groups obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group in which one of the hydrogen atoms of the aromatic ring is substituted with an alkylene group (e.g., benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2- 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.

The cyclic aliphatic hydrocarbon group for Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ includes an aliphatic hydrocarbon group containing a ring in its structure.
The aliphatic hydrocarbon group containing a ring in this structure includes an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group intervenes in the middle of a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples 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 preferably has 7 to 30 carbon atoms. Among them, the polycycloalkanes include polycycloalkanes having a bridged ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; condensed ring systems such as cyclic groups having a steroid skeleton; Polycycloalkanes having a polycyclic skeleton of are more preferred.

Among them, the cyclic aliphatic hydrocarbon group in Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ is preferably a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane. , is more preferably a group obtained by removing one hydrogen atom from monocycloalkane, and particularly preferably a group obtained by removing one hydrogen atom from cyclopentane or cyclohexane.

The linear 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 1 to 4 carbon atoms. is more preferred, and those with 1 to 3 carbon atoms are most preferred. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specifically, a methylene group [ _--CH.sub.2-- ], an ethylene group [--( _CH.sub.2 ) _.sub.2-- ], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -] and the like.
The branched aliphatic hydrocarbon group, which may be bonded to the alicyclic hydrocarbon group, preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, and 3 or 4 carbon atoms. is more preferred, and one having 3 carbon atoms is most preferred. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) _2- , -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups;- 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 Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ - and -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples 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 cyclic groups Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ are -COOR ^XYZ and -OC(=O)R ^XYZ where R ^XYZ is a lactone-containing cyclic group; Also included are carbonate-containing cyclic groups or —SO ₂ —-containing cyclic groups.

Examples of substituents in the cyclic groups Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ include alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxyl groups, nitro groups and carbonyl groups. etc.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group and a tert-butoxy group. Most preferred is the ethoxy group.
A halogen atom as a substituent includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.
Halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, tert-butyl, etc., wherein some or all of the hydrogen atoms are Groups substituted with halogen atoms are included.
A carbonyl group as a substituent is a group that substitutes a methylene group ( _--CH.sub.2-- ) constituting a cyclic hydrocarbon group.
Among them, the substituents for the cyclic groups Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ are, from the viewpoint of compatibility with the component (A), alkyl groups, halogen atoms, and halogenated alkyl groups. groups are preferred, and alkyl groups are more preferred.

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

A chain alkenyl group which may have a substituent:
The chain alkenyl groups represented by Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ may be linear or branched and preferably have 2 to 10 carbon atoms, It preferably has 2 to 5 carbon atoms, more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group and the like.
Among the above, the chain alkenyl group is preferably a linear alkenyl group, more preferably a vinyl group or a propenyl group, and particularly preferably a vinyl group.

Examples of substituents in the chain alkyl or alkenyl groups of Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ include alkoxy groups, halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, atoms, etc.), halogenated alkyl groups, hydroxyl groups, carbonyl groups, nitro groups, amino groups, cyclic groups in the above Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² , Rz ¹ to Rz ⁴ and the like. Among them, the substituents for the chain alkyl or alkenyl groups of Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ are halogen atoms, halogen alkyl groups, the groups listed as the cyclic groups in the above Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ are preferred, and the above Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² , Rz ¹ to The groups listed as the cyclic group for Rz ⁴ are more preferred.

The hydrocarbon groups in Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ are, among the above hydrocarbon groups, cyclic groups which may have a substituent, and A chain alkyl group which may be substituted is preferred.

In the formula (bd1), Ry ¹ to Ry ² may be mutually bonded to form a ring structure.
The ring structure formed by such Ry ¹ to Ry ² shares one side of the six-membered ring (the bond between the carbon atoms to which Ry ¹ and Ry ² are respectively bonded) in the formula (bd1), and this ring structure is It may be an alicyclic hydrocarbon or an aromatic hydrocarbon. Also, this ring structure may be a polycyclic structure consisting of other ring structures.

The alicyclic hydrocarbon formed by Ry ¹ to Ry ² may be polycyclic or monocyclic. A monocycloalkane is preferred as the monocyclic alicyclic hydrocarbon. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. Polycycloalkanes are preferred as polycyclic alicyclic hydrocarbons. The polycycloalkane preferably has 7 to 30 carbon atoms, and specifically polycycloalkanes having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; A polycycloalkane having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton is more preferable.

The aromatic hydrocarbon ring formed by Ry ¹ to Ry ² is benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heteroaromatic ring in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. rings and the like. The aromatic hydrocarbon ring formed by Ry ¹ to Ry ² preferably does not contain a heteroatom from the viewpoint of compatibility with the component (A), and includes aromatic hydrocarbon rings such as benzene, fluorene, naphthalene, anthracene, phenanthrene, and biphenyl. A ring is more preferred.

The ring structure (alicyclic hydrocarbon, aromatic hydrocarbon) formed by Ry ¹ to Ry ² may have a substituent. The substituents here include the substituents in the cyclic groups Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ described above (e.g., alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups , hydroxyl group, nitro group, carbonyl group, etc.).
Among them, the substituent in the ring structure formed by Ry ¹ to Ry ² is preferably an alkyl group, a halogen atom, a halogenated alkyl group, etc., more preferably an alkyl group, from the viewpoint of compatibility with the component (A).

The ring structure formed by Ry ¹ to Ry ² is more preferably an aromatic hydrocarbon which may have a substituent, from the viewpoints of short diffusion of acid generated by exposure and controllability of acid diffusion.

In formula (bd1), two or more of Rz ¹ to Rz ⁴ may be mutually bonded to form a ring structure. For example, Rz ¹ may form a ring structure with any of Rz ² to Rz ⁴ . Specifically, one side of the six-membered ring in formula (bd1) (the bond between the carbon atom to which Rz ¹ and Rz ² are bonded and the carbon atom to which Rz ³ and Rz ⁴ are bonded) is shared. Examples include a ring structure, a ring structure formed by combining Rz ¹ and Rz ² , and a ring structure formed by combining Rz ³ and Rz ⁴ .
The ring structure formed by two or more of Rz ¹ to Rz ⁴ may be an alicyclic hydrocarbon or an aromatic hydrocarbon, particularly an aromatic hydrocarbon. preferable. Also, this ring structure may be a polycyclic structure consisting of other ring structures.

The alicyclic hydrocarbon formed by two or more of Rz ¹ to Rz ⁴ may be polycyclic or monocyclic. A monocycloalkane is preferred as the monocyclic alicyclic hydrocarbon. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. Polycycloalkanes are preferred as polycyclic alicyclic hydrocarbons. The polycycloalkane preferably has 7 to 30 carbon atoms, and specifically polycycloalkanes having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; A polycycloalkane having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton is more preferable.
A heterocyclic structure in which a portion of the carbon atoms are substituted with a heteroatom is also acceptable, and a nitrogen-containing heterocyclic ring is particularly preferred, and specific examples thereof include cyclic imides and the like.

The aromatic hydrocarbon ring formed by two or more of Rz ¹ to Rz ⁴ is benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or some of the carbon atoms constituting these aromatic rings are heteroatoms. A substituted aromatic heterocycle and the like can be mentioned. The aromatic hydrocarbon ring formed by two or more of Rz ¹ to Rz ⁴ preferably does not contain a heteroatom from the viewpoint of compatibility with component (A), and includes benzene, fluorene, naphthalene, anthracene, Aromatic rings such as phenanthrene and biphenyl are more preferred.

The ring structure (alicyclic hydrocarbon, aromatic hydrocarbon) formed by Rz ¹ to Rz ⁴ may have a substituent. The substituents here include the substituents in the cyclic groups Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ described above (e.g., alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups , hydroxyl group, nitro group, carbonyl group, etc.).
Among them, the substituents in the ring structure formed by Rz ¹ to Rz ⁴ are preferably alkyl groups, halogen atoms, halogenated alkyl groups, etc., more preferably alkyl groups, from the viewpoint of compatibility with the component (A).

The ring structure formed by two or more of Rz ¹ to Rz ⁴ is one side (Rz ¹ and Rz ² and the carbon atom to which Rz ³ and Rz ⁴ are bonded) is preferred, and an aromatic ring structure is more preferred.

In the above formula (bd1), "when the valence permits" is as follows.
That is, when the bond between the carbon atom to which Rz ¹ and Rz ² are bonded and the carbon atom to which Rz ³ and Rz ⁴ are bonded is a single bond, Rz ¹ , Rz ² , Rz ³ and Rz All ⁴ are present. When the bond between the carbon atom to which Rz ¹ and Rz ² are bonded and the carbon atom to which Rz ³ and Rz ⁴ are bonded is a double bond, only one of Rz ¹ and Rz ² is present. , and only one of Rz ³ and Rz ⁴ is present. Further, for example, when Rz ¹ and Rz ³ are combined to form an aromatic ring structure, Rz ² and Rz ⁴ do not exist.

In the formula (bd1), two or more of Rx ¹ to Rx ⁴ may be mutually bonded to form a ring structure. For example, Rx ¹ may form a ring structure with any of Rx ² to Rx ⁴ .
A ring structure formed by two or more of Rx ¹ to Rx ⁴ may be an alicyclic hydrocarbon or an aromatic hydrocarbon. Also, this ring structure may be a polycyclic structure consisting of other ring structures.

The alicyclic hydrocarbon formed by two or more of Rx ¹ to Rx ⁴ may be polycyclic or monocyclic. A monocycloalkane is preferred as the monocyclic alicyclic hydrocarbon. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. Polycycloalkanes are preferred as polycyclic alicyclic hydrocarbons. The polycycloalkane preferably has 7 to 30 carbon atoms, and specifically polycycloalkanes having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; A polycycloalkane having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton is more preferable.

The aromatic hydrocarbon ring formed by two of Rx ¹ to Rx ⁴ is benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. and aromatic heterocycles. The aromatic hydrocarbon ring formed by two of Rx ¹ to Rx ⁴ preferably does not contain a heteroatom from the viewpoint of compatibility with the component (A), and includes benzene, fluorene, naphthalene, anthracene, and phenanthrene. , biphenyl and the like are more preferred.

The ring structure (alicyclic hydrocarbon, aromatic hydrocarbon) formed by Rx ¹ to Rx ⁴ may have a substituent. The substituents here include the substituents in the cyclic groups Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ described above (e.g., alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups , hydroxyl group, nitro group, carbonyl group, etc.).
Among them, the substituents in the ring structure formed by Rx ¹ to Rx ⁴ are preferably alkyl groups, halogen atoms, halogenated alkyl groups and the like, more preferably alkyl groups, from the viewpoint of compatibility with the component (A).

The ring structure formed by two or more of Rx ¹ to Rx ⁴ is preferably an alicyclic hydrocarbon from the viewpoint of acid diffusion controllability.
In addition, the ring structure formed by two or more of Rx ¹ to Rx ⁴ is, among others, from the standpoint of acid diffusion controllability, at least one of Rx ¹ to Rx ² and Rx ³ to Rx ⁴ at least one of which is preferably bonded to each other to form a crosslinked ring structure, and more preferably the ring structure is an alicyclic hydrocarbon.

A bicyclic structure ^{( Ry 1 , Ry 2} , Rz ¹ and Rz ² , Rz ³ and Rz ⁴ ) is preferably 7 to 16 carbon atoms.

In the formula (bd1), at least one of Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the anion part as a whole becomes an n-valent anion. n is an integer of 1 or more.
By selecting an anionic group in the molecule, the component (BD1) can be used as an acid generator component (B) that generates an acid that acts on the substrate component (A) in the resist composition, or by exposure (B ) functions as a base component (D) that traps the acid generated from the component (controls acid diffusion).
In the component (BD1), each of Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ may be the anionic group. Alternatively, in the component (BD1), when two or more of Rx ¹ to Rx ⁴ are bonded to each other to form a ring structure, the carbon atom forming the ring structure or the hydrogen atom bonded to this carbon atom may be substituted with the anionic group. When two or more of Ry ¹ to Ry ² are bonded to each other to form a ring structure, the carbon atom forming the ring structure or the hydrogen atom bonded to the carbon atom is substituted with the anion group. good too. When two or more of Rz ¹ to Rz ⁴ are mutually bonded to form a ring structure, the carbon atom forming the ring structure or the hydrogen atom bonded to the carbon atom is substituted with the anion group; good too.

The anion groups possessed by Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ include sulfonate anion structure, carboxylate anion structure, imide anion structure, methide anion structure, carbanion structure, borate anion structure, halogen Examples thereof include those having an anion structure, a phosphate anion structure, an antimonate anion structure, an arsenate anion structure, and the like. Among these, those having a sulfonate anion structure and those having a carboxylate anion structure are preferred.

As the anionic group having the carboxylate anion structure, *-V' ¹⁰ -COO ^- (V' ¹⁰ is a single bond or an alkylene group having 1 to 20 carbon atoms) is preferable.

Examples of the anion group having the sulfonate anion structure include *-V' ¹¹ -SO ₃ ^- (V' ¹¹ is a single bond or an alkylene group having 1 to 20 carbon atoms) and the following general formula (bd1- Preferable examples include the anionic group represented by r-an1).
In the formula (bd1-r-an1), * indicates a bond. * means a bond with the carbon atom to which Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ are bonded.

［式中、Ｒ^ｂ０１は、炭素数１～５のフッ素化アルキル基又はフッ素原子を表す。Ｖ^ｂ０１は、アルキレン基、フッ素化アルキレン基又は単結合を表す。Ｙ^ｂ０１は、２価の連結基又は単結合を表す。］

[In the formula, R ^b01 represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. V ^b01 represents an alkylene group, a fluorinated alkylene group, or a single bond. ^Yb01 represents a divalent linking group or a single bond. ]

In the formula (bd1-r-an1), R ^b01 represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. R ^b01 is preferably a C 1-5 perfluoroalkyl group or a fluorine atom, more preferably a fluorine atom.

In the formula (bd1-r-an1), V ^b01 represents an alkylene group, a fluorinated alkylene group or a single bond.
The alkylene group and the fluorinated alkylene group in V ^b01 each preferably have 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms. Examples of the fluorinated alkylene group for V ^b01 include groups in which some or all of the hydrogen atoms in an alkylene group are substituted with fluorine atoms. Among them, V ^b01 is preferably an alkylene group having 1 to 4 carbon atoms, a fluorinated alkylene group having 1 to 4 carbon atoms, or a single bond.

In the formula (bd1-r-an1), Y ^b01 represents a divalent linking group or a single bond.
The divalent linking group for ^Yb01 is preferably a divalent linking group containing an oxygen atom.
When Y ^b01 is a divalent linking group containing an oxygen atom, Y ^b01 may contain an atom other than an oxygen atom. Atoms other than an oxygen atom include, for example, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, and the like.
The divalent linking group containing an oxygen atom includes, for example, an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O )-), amide bond (-C(=O)-NH-), carbonyl group (-C(=O)-), carbonate bond (-OC(=O)-O-), etc. and a combination of the non-hydrocarbon oxygen atom-containing linking group and an alkylene group. A sulfonyl group ( _--SO.sub.2-- ) may be further linked to this combination.
Such divalent linking groups containing an oxygen atom include, for example, linking groups represented by general formulas (y-al-1) to (y-al-8) below.

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

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

The divalent saturated hydrocarbon group for V' ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and an alkylene group having 1 to 5 carbon atoms. is more preferable.

The alkylene group for V' ¹⁰¹ and V' ¹⁰² may be a straight-chain alkylene group or a branched alkylene group, and a straight-chain alkylene group is preferred.
Specific examples of the alkylene group for V' ¹⁰¹ and V' ¹⁰² include a methylene group [-CH ₂ -]; -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups; ethylene groups [-CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ ) 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 ) Alkyltrimethylene groups such as CH ₂ -; Tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ Alkyltetramethylene groups such as CH ₂ —; pentamethylene groups [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like.
Further, part of the methylene groups in the alkylene group in ^V'101 or ^V'102 may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group.

Y ^b01 is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, represented by the above formulas (y-al-1) to (y-al-6), respectively. Linking groups are more preferred.

Specific examples of the anionic group represented by the formula (bd1-r-an1) include, for example,
When Y ^b01 is a single bond, it includes -CH ₂ CF ₂ SO ₃ ^- , -CF ₂ CF ₂ SO ₃ ^- , and fluorinated alkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion.
When Y ^b01 is a divalent linking group containing an oxygen atom, an anion represented by any one of the following formulas (bd1-r-an11) to (bd1-r-an13) can be mentioned.

［式中、Ｖ”^１０１は、単結合、炭素数１～４のアルキレン基、又は炭素数１～４のフッ素化アルキレン基である。Ｒ^１０２は、フッ素原子又は炭素数１～５のフッ素化アルキル基である。ｖ”はそれぞれ独立に０～３の整数である。ｑ”はそれぞれ独立に１～２０の整数である。ｎ”は０または１である。］

[In the formula, V″ ¹⁰¹ is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. R ¹⁰² is a fluorine atom or a fluorinated It is an alkyl group. Each v″ is independently an integer of 0 to 3. q″ is each independently an integer of 1 to 20; n″ is 0 or 1; ]

In the formulas (bd1-r-an11) to (bd1-r-an13), V″ ¹⁰¹ is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. V″ ¹⁰¹ is preferably a single bond, an alkylene group having 1 carbon atom (methylene group), or a fluorinated alkylene group having 1 to 3 carbon atoms.

In the formulas (bd1-r-an11) to (bd1-r-an13), R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ¹⁰² is preferably a C 1-5 perfluoroalkyl group or a fluorine atom, more preferably a fluorine atom.

In the formulas (bd1-r-an11) to (bd1-r-an13), v″ is an integer of 0 to 3, preferably 0 or 1.
q″ is an integer of 1 to 20, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, still more preferably 1, 2 or 3, particularly preferably 1 or 2 is.
n″ is 0 or 1, preferably 0;

The number of anionic groups in the component (BD1) may be one or two or more, preferably one.
The component (BD1) becomes an n-valent anion in the entire anion portion. n is an integer of 1 or more, preferably 1 or 2, more preferably 1.

The anion portion in the component (BD1) is preferably an anion represented by the following general formula (bd1-an1) from the viewpoint of acid diffusion controllability.

［式中、Ｒｘ^５～Ｒｘ^６はそれぞれ独立に、置換基を有してもよい炭化水素基又は水素原子を表す。Ｒｘ^７～Ｒｘ^８は、それぞれ独立に、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は相互に結合して環構造を形成していてもよい。ｐは、１又は２であり、ｐ＝２の場合、複数のＲｘ^７～Ｒｘ^８は相互に異なっていてもよい。Ｒｙ^１～Ｒｙ^２は、それぞれ独立に、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は相互に結合して環構造を形成していてもよい。

は二重結合又は単結合である。Ｒｚ^１～Ｒｚ^４は、それぞれ独立に、原子価が許容する場合、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は２個以上が相互に結合して環構造を形成していてもよい。但し、Ｒｘ^５～Ｒｘ^８、Ｒｙ^１～Ｒｙ^２及びＲｚ^１～Ｒｚ^４のうち少なくとも１個はアニオン基を有し、アニオン部全体でｎ価のアニオンとなる。ｎは１以上の整数である。］

[In the formula, Rx ⁵ to Rx ⁶ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom. Rx ⁷ to Rx ⁸ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure. p is 1 or 2, and when p=2, a plurality of Rx ⁷ to Rx ⁸ may be different from each other. Ry ¹ to Ry ² each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure.

is a double bond or a single bond. Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have However, at least one of Rx ⁵ to Rx ⁸ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the entire anion part becomes an n-valent anion. n is an integer of 1 or more. ]

In the formula (bd1-an1), Rx ⁵ to Rx ⁶ each independently represent a hydrocarbon group which may have a substituent or a hydrogen atom. The hydrocarbon groups optionally having substituents in Rx ⁵ to Rx ⁶ are the hydrocarbon groups optionally having substituents in Rx ¹ to Rx ⁴ in the above formula (bd1). is similar to

In the formula (bd1-an1), Rx ⁷ to Rx ⁸ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or combine with each other to form a ring structure. may Such Rx ⁷ to Rx ⁸ are the same as the description of Rx ¹ to Rx ⁴ in the above formula (bd1).

In the formula (bd1-an1), p is 1 or 2, and when p=2, a plurality of Rx ⁷ to Rx ⁸ may be different from each other. The anion represented by the general formula (bd1-an1) has a bicycloheptane ring structure when p=1, and a bicyclooctane ring structure when p=2.

In the formula (bd1-an1), Ry ¹ to Ry ² each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or combine with each other to form a ring structure. may Such Ry ¹ to Ry ² are the same as Ry ¹ to Ry ² in the above formula (bd1).
Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have Such Rz ¹ to Rz ⁴ are the same as Rz ¹ to Rz ⁴ in the above formula (bd1).

However, in the formula (bd1-an1), at least one of Rx ⁵ to Rx ⁸ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the entire anion portion becomes an n-valent anion. . n is an integer of 1 or more.

Among the above, the anion moiety in the component (BD1) is an anion represented by p = 2 in the formula (bd1-an1) from the viewpoint of acid diffusion controllability, that is, the following general formula (bd1-an2 ) is more preferred.

［式中、Ｒｘ^５～Ｒｘ^６はそれぞれ独立に、置換基を有してもよい炭化水素基又は水素原子を表す。複数のＲｘ^７～Ｒｘ^８は、それぞれ独立に、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は２個以上が相互に結合して環構造を形成していてもよい。Ｒｙ^１～Ｒｙ^２は、それぞれ独立に、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は相互に結合して環構造を形成していてもよい。

は二重結合又は単結合である。Ｒｚ^１～Ｒｚ^４は、それぞれ独立に、原子価が許容する場合、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は２個以上が相互に結合して環構造を形成していてもよい。但し、Ｒｘ^５～Ｒｘ^８、Ｒｙ^１～Ｒｙ^２及びＲｚ^１～Ｒｚ^４のうち少なくとも１個はアニオン基を有し、アニオン部全体でｎ価のアニオンとなる。ｎは１以上の整数である。］

[In the formula, Rx ⁵ to Rx ⁶ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom. A plurality of Rx ⁷ to Rx ⁸ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or two or more of them may bond together to form a ring structure. . Ry ¹ to Ry ² each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure.

is a double bond or a single bond. Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have However, at least one of Rx ⁵ to Rx ⁸ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the entire anion part becomes an n-valent anion. n is an integer of 1 or more. ]

In formula (bd1-an2), Rx ⁵ to Rx ⁶ , Rx ⁷ to Rx ⁸ , Ry ¹ to Ry ² , Rz ¹ to Rz ⁴ are Rx ⁵ to Rx ⁶ and Rx in formula (bd1) described above. ⁷ to Rx ⁸ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ respectively.

However, in the formula (bd1-an2), at least one of Rx ⁵ to Rx ⁸ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the entire anion portion becomes an n-valent anion. . n is an integer of 1 or more.

In the formulas (bd1), (bd1-an1), and (bd1-an2), Ry ¹ to Ry ² are mutually It is preferable that they combine to form a ring structure, and the ring structure to be formed is more preferably an aromatic hydrocarbon (aromatic ring, aromatic heterocyclic ring) that may have a substituent.

In the above formulas (bd1), (bd1-an1), and (bd1-an2), Rz ¹ to Rz ⁴ are bonded to each other to form a ring structure from the viewpoint of the diffusion controllability of the acid generated by exposure. The ring structure to be formed is one side of the six-membered ring in the formula (the carbon atom to which Rz ¹ and Rz ² are bonded and the carbon atom to which Rz ³ and Rz ⁴ are bonded is preferred, and an optionally substituted aromatic hydrocarbon (aromatic ring, aromatic heterocyclic ring) is more preferred.

In the above formulas (bd1-an1) and (bd1-an2), Rx ⁷ to Rx ⁸ are mutually bonded to form a ring structure from the viewpoint of short diffusion of acid generated by exposure and controllability of acid diffusion. is preferably formed, and the ring structure to be formed is more preferably an aromatic hydrocarbon (aromatic ring, aromatic heterocyclic ring) which may have a substituent.
In the formula (bd1-an2), the ring structures formed by Rx ⁷ to Rx ⁸ share one side of the six-membered ring in the formula (a bond between the same carbon atoms to which Rx ⁷ and Rx ⁸ are bonded) is preferable, and an optionally substituted aromatic hydrocarbon (aromatic ring, aromatic heterocyclic ring) is more preferable.

In each of Rx ⁷ to Rx ⁸ , Ry ¹ to Ry ² , and Rz ¹ to Rz ⁴ in all the anions represented by the above formula (bd1-an2), the number of ring structures formed by mutual bonding is , may be one or two or more, preferably two or three.

In particular, the anion moiety in the component (BD1) is preferably an anion represented by the following general formula (bd1-an3).

［式中、Ｒｘ^５～Ｒｘ^６はそれぞれ独立に、置換基を有してもよい炭化水素基又は水素原子を表す。

は二重結合又は単結合である。Ｒｚ^１～Ｒｚ^４は、それぞれ独立に、原子価が許容する場合、置換基を有してもよい炭化水素基もしくは水素原子を表すか、又は２個以上が相互に結合して環構造を形成していてもよい。但し、Ｒｘ^５～Ｒｘ^６及びＲｚ^１～Ｒｚ^４のうち少なくとも１個はアニオン基を有し、アニオン部全体でｎ価のアニオンとなる。ｎは１以上の整数である。Ｒ^０２１は、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、カルボニル基又はニトロ基である。ｎ１は１～３の整数である。ｎ１１は０～８の整数である。Ｒ^０２２は、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、カルボニル基又はニトロ基である。ｎ２は１～３の整数である。ｎ２１は０～８の整数である。］

[In the formula, Rx ⁵ to Rx ⁶ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom.

is a double bond or a single bond. Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have However, at least one of Rx ⁵ to Rx ⁶ and Rz ¹ to Rz ⁴ has an anion group, and the entire anion part becomes an n-valent anion. n is an integer of 1 or more. R ⁰²¹ is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group or a nitro group. n1 is an integer of 1-3. n11 is an integer of 0-8. R ⁰²² is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group or a nitro group. n2 is an integer of 1-3. n21 is an integer of 0-8. ]

In formula (bd1-an3), Rx ⁵ to Rx ⁶ and Rz ¹ to Rz ⁴ are the same as Rx ⁵ to Rx ⁶ and Rz ¹ to Rz ⁴ in formula (bd1-an1).

In the above formula (bd1-an3), R ⁰²¹ is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, a carbonyl group or a nitro group.
The alkyl group for R ⁰²¹ is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group.
The alkoxy group for R ⁰²¹ 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 and a tert-butoxy group, and a methoxy group. , ethoxy groups are most preferred.
The halogen atom for R ⁰²¹ includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, with a fluorine atom being preferred.
The halogenated alkyl group for R ⁰²¹ includes an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc., wherein some or all of the hydrogen atoms are the above halogen Atomically substituted groups are included. Among them, R ⁰²¹ is preferably an alkyl group, a halogen atom, a halogenated alkyl group, or the like, more preferably an alkyl group, from the viewpoint of compatibility with the component (A).

In the formula (bd1-an3), n1 is an integer of 1 to 3, preferably 1 or 2, particularly preferably 1.
In the formula (bd1-an3), n11 is an integer of 0 to 8, preferably an integer of 0 to 4, more preferably 0, 1 or 2, particularly preferably 0 or 1.

In the above formula (bd1-an3), R ⁰²² is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, a carbonyl group or a nitro group, each of which is the same as the above R ⁰²¹ . . Among them, R ⁰²² is preferably an alkyl group, a halogen atom, a halogenated alkyl group, or the like, more preferably an alkyl group, from the viewpoint of compatibility with the component (A).
In the formula (bd1-an3), n2 is an integer of 1 to 3, preferably 1 or 2, particularly preferably 1.
In the formula (bd1-an3), n21 is an integer of 0 to 8, preferably 0 to 4, more preferably 0, 1 or 2, particularly preferably 0 or 1.

However, in the above formula (bd1-an3), at least one of Rx ⁵ to Rx ⁶ and Rz ¹ to Rz ⁴ has an anion group, and the entire anion part becomes an n-valent anion. n is an integer of 1 or more.
Examples of the anion group include *-V' ^{10 -COO-} (V' ¹⁰ is a single bond or an alkylene group having 1 to 5 carbon atoms), represented by the general formula (bd1-r-an1) described above. An anionic group is preferably exemplified.

In the formulas (bd1), (bd1-an1), (bd1-an2), and (bd1-an3), at least one of Rz ¹ to Rz ⁴ is , preferably has an anionic group. When two or more of Rz ¹ to Rz ⁴ are bonded to each other to form a ring structure, the carbon atom forming the ring structure or the hydrogen atom bonded to the carbon atom is substituted with the anion group. may

Alternatively, in the formulas (bd1-an1), (bd1-an2), and (bd1-an3), at least one of the Rx ⁵ to Rx ⁶ is an anionic group from the viewpoint of excellent effects of the present invention. It is preferred to have

Specific examples of the anion moiety in compound (BD1) are described below.

- Regarding the cation moiety ((M ^m+ ) _1/m ) In the formula (bd1), M ^m+ represents an m-valent organic cation. m is an integer of 1 or more.

Sulfonium cations and iodonium cations are preferred as organic cations for Mm ⁺ . Moreover, when using a (BD1) component as a base component (D), an ammonium cation is also mentioned.

Preferred cation moieties ((M ^m+ ) _1/m ) include organic cations represented by general formulas (ca-1) to (ca-4) below.

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

[wherein R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² are each independently an aryl group optionally having a substituent, an alkyl group optionally having a substituent, or represents a good alkenyl group. Each of R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ and R ²¹¹ to R ²¹² may be mutually bonded to form a ring together with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, or may combine with each other to form a ring together with the sulfur atom in the formula. R ²¹⁰ is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ₂ — It contains cyclic groups. L ²⁰¹ represents -C(=O)- or -C(=O)-O-. A plurality of Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group. x is 1 or 2; W ²⁰¹ represents a (x+1)-valent linking group. ]

The aryl group for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² includes an aryl group having 6 to 20 carbon atoms, preferably a phenyl group or a naphthyl group.
The alkyl group for 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 for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² preferably has 2 to 10 carbon atoms.
Examples of substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² may have include alkyl groups, halogen atoms, halogenated alkyl groups, carbonyl groups, cyano groups, amino groups, aryl groups, and the following general Groups represented by formulas (ca-r-1) to (ca-r-7) are exemplified.

［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。］

[In the formula, each R′ ²⁰¹ is independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted chain alkyl group, or a substituted is a chain alkenyl group that may be ]

The cyclic group optionally having substituent(s), the chain alkyl group optionally having substituent(s), or the chain alkenyl group optionally having substituent(s) for R′ ²⁰¹ are those described above. In addition to the same as those described for Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ in the formula (bd1) of (bd1), a cyclic group optionally having a substituent or a substituent Examples of the chain alkyl group which may have a group include those similar to the acid dissociable group represented by the above formula (a1-r-2).

Each of R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ and R ²¹¹ to R ²¹² may be mutually bonded to form a ring together with the sulfur atom in the formula.
When R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ and R ²¹¹ to R ²¹² are mutually bonded to form a ring together with the sulfur atom in the formula, heteroatoms such as a sulfur atom, an oxygen atom and a nitrogen atom, carbonyl group, -SO-, -SO ₂ -, -SO ₃ -, -COO-, -CONH- or -N(R _N )- (where R _N is an alkyl group having 1 to 5 carbon atoms), etc. may be bonded via the functional group of As the ring to be formed, one ring containing a sulfur atom in the formula in its ring skeleton is preferably a 3- to 10-membered ring including a sulfur atom, particularly a 5- to 7-membered ring. preferable. Specific examples of the ring formed include 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 phenoxathiine ring, a tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, and the like are included.

R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. A ring may be formed together with the sulfur atom in the formula.

R ²¹⁰ is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ₂ — It contains cyclic groups.
The aryl group for R ²¹⁰ includes an unsubstituted aryl group having 6 to 20 carbon atoms, preferably a phenyl group or a naphthyl group.
The alkyl group for R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms.
The —SO ₂ -containing cyclic group optionally having a substituent for R ²¹⁰ is preferably a “—SO ₂ -containing polycyclic group” represented by the above general formula (a5-r-1). is more preferred.

Each Y ²⁰¹ independently represents an arylene group, an alkylene group or an alkenylene group.
The arylene group for Y ²⁰¹ is an aryl group exemplified as the aromatic hydrocarbon group for Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² , and Rz ¹ to Rz ⁴ in the formula (bd1) above, with one more hydrogen atom added. groups excepted.
The alkylene group and alkenylene group for Y ²⁰¹ are exemplified as the chain alkyl groups and chain alkenyl groups for Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² , and Rz ¹ to Rz ⁴ in the above formula (bd1). A group obtained by removing one hydrogen atom from the group can be mentioned.

In formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x+1)-valent, ie divalent or trivalent linking group.
The divalent linking group in W ²⁰¹ is preferably a divalent hydrocarbon group which may have a substituent, and is the same as described for Ya ^x0 in formula (a0) above. The divalent linking group in W ²⁰¹ may be linear, branched or cyclic, preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. The arylene group includes a phenylene group, a naphthylene group and the like, and a phenylene group is particularly preferred.
The trivalent linking group for W ²⁰¹ includes a group obtained by removing one hydrogen atom from the divalent linking group for W ²⁰¹ , a group obtained by further bonding the divalent linking group to the divalent linking group, and the like. mentioned. The trivalent linking group for W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

Specific examples of suitable cations represented by the formula (ca-1) include the following chemical formulas (ca-1-1) to (ca-1-78), (ca-1-101) to (ca- 1-149), respectively.
In the chemical formula below, g1 represents the number of repetitions and g1 is an integer of 1-5. g2 indicates the number of repetitions, and g2 is an integer of 0-20. g3 indicates the number of repetitions, and g3 is an integer of 0-20.

［式中、ｇ１は繰返し数を示し、ｇ１は１～５の整数である。］

[In the formula, g1 represents the number of repetitions, and g1 is an integer of 1 to 5. ]

［式中、ｇ２は繰返し数を示し、ｇ２は０～２０の整数である。］

[In the formula, g2 represents the number of repetitions, and g2 is an integer of 0 to 20. ]

［式中、Ｒ”^２０１は水素原子又は置換基である。該置換基としては、上記Ｒ^２０１～Ｒ^２０７およびＲ^２１１～Ｒ^２１２が有してもよい置換基として挙げた、アルキル基、ハロゲン原子、ハロゲン化アルキル基、カルボニル基、シアノ基、アミノ基、アリール基、一般式（ｃａ－ｒ－１）～（ｃａ－ｒ－７）でそれぞれ表される基が挙げられる。］

[In the formula, R ^{″ 201} is a hydrogen ^atom or a substituent ^. Examples of the substituent include ^the alkyl group, halogen atoms, halogenated alkyl groups, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by general formulas (ca-r-1) to (ca-r-7).]

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

Specific examples of suitable cations represented by formula (ca-3) include cations represented by formulas (ca-3-1) to (ca-3-7) below.

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

Further, as the ammonium cation when the component (BD1) is used as the base component (D), NH ₄ ⁺ or a cation in which H bound to the nitrogen atom is substituted with a hydrocarbon group which may have a heteroatom. (Primary to quaternary ammonium cations) or cyclic cations formed with a nitrogen atom thereof.

Among the above, the cation moiety ((M ^m+ ) _1/m ) is preferably a cation represented by the general formula (ca-1), and each of the formulas (ca-1-1) to (ca-1-78) The cations represented are more preferred.
Among them, a cation in which one or more of R ²⁰¹ to R ²⁰³ in general formula (ca-1) is an aryl group having an electron-withdrawing group as a substituent is more preferable. The electron-withdrawing group is preferably a halogen atom or a halogenated alkyl group, more preferably a fluorine atom or a fluorinated alkyl group. Specifically, cations represented by the above formulas (ca-1-1) to (ca-1-17) are preferred.

Further, as the ammonium cation when the component (BD1) is used as the base component (D), NH ₄ ⁺ or a cation in which H bound to the nitrogen atom is substituted with a hydrocarbon group which may have a heteroatom. (Primary to quaternary ammonium cations) or cyclic cations formed with a nitrogen atom thereof.

Among the above, the cation moiety ((M ^m+ ) _1/m ) is preferably a cation represented by general formula (ca-1), and chemical formulas (ca-1-1) to (ca-1-78), ( Cations represented by ca-1-101) to (ca-1-149) are more preferred.

Among the components (BD1) described above, specific examples of compounds suitable as the acid generator component (B) (hereinafter also referred to as "(B1) component") that generates an acid acting on the component (A) are shown below. Listed in

In the resist composition of this embodiment, the component (B1) may be used singly or in combination of two or more.
In the resist composition of the present embodiment, the content of component (B1) is preferably 5 to 65 parts by mass, more preferably 5 to 55 parts by mass, with respect to 100 parts by mass of component (A). It is preferably 10 to 45 parts by mass, particularly preferably 10 to 40 parts by mass.
In the resist composition, the proportion of the component (B1) in the total acid generator component (B) component that generates an acid acting on the component (A) is, for example, 50% by mass or more, preferably 70% by mass. % or more, more preferably 95 mass % or more. In addition, 100 mass % may be sufficient.
When the content of component (B1) is at least the lower limit of the above preferred range, lithography properties such as sensitivity, resolution performance, LWR (linewise roughness) reduction, and shape are further improved in resist pattern formation. On the other hand, if it is equal to or less than the upper limit of the preferable range, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, and the storage stability of the resist composition is further enhanced.
In addition, when the resist composition contains both the component (B1) and the component (D) (at least one of the components (D1) to (D3)), the ratio (molar ratio) thereof provides good lithography properties and resist For example, (B1):(D)=100:0 to 50:50, more preferably (B1):(D)=99:1 to 51:49, and (B1 ):(D)=90:10 to 60:40 is more preferable.

Further, among the above-mentioned (BD1) components, a base component (D) (hereinafter also referred to as "(D1) component") that traps (controls acid diffusion) the acid generated from the (B) component upon exposure. Specific examples of compounds suitable for are given below.

In the resist composition of this embodiment, the component (D1) may be used singly or in combination of two or more.
In the resist composition of the present embodiment, the content of the component (D1) is preferably 1 to 35 parts by mass, more preferably 2 to 25 parts by mass, and 3 to 20 parts by mass with respect to 100 parts by mass of the component (A). parts is more preferred, and 3.5 to 15 parts by mass is particularly preferred.
In the resist composition, the proportion of the component (D1) in the entire base component (D) that traps (controls acid diffusion) the acid generated from the component (B) upon exposure is, for example, 50% by mass or more. , preferably 70% by mass or more, more preferably 95% by mass or more. In addition, 100 mass % may be sufficient.
When the content of component (D1) is at least the lower limit of the preferred range, it is easy to obtain good lithography properties and resist pattern shape. On the other hand, when it is at most the upper limit of the preferable range, the balance with other components can be achieved, and various lithographic properties are improved.
In addition, when the resist composition contains both the component (D1) and the component (B) (at least one of the components (B1) to (B2)), the ratio (molar ratio) thereof provides good lithography properties and resist For example, (B):(D1) = 100:0 to 50:50, more preferably (B):(D1) = 99:1 to 51:49, from the point of easily obtaining a pattern shape, and (B ):(D1)=90:10 to 60:40 is more preferable.

[Method for producing compound (BD1)]
(BD1) component can be manufactured using a well-known method.
As a method for producing the component (BD1), for example, as in the following reaction formula, an alkene or alkyne ((starting material 2) in the following reaction formula) is converted to a conjugated diene ((starting material 1) in the following reaction formula). A method using the Diels-Alder reaction in which a ring structure is produced by addition ((intermediate) in the following reaction formula) can be mentioned. Specifically, the desired anion group is introduced into the product (intermediate) by the Diels-Alder reaction to obtain a precursor, and then the desired cation is introduced by a salt exchange reaction to obtain the desired (BD1) components are obtained. Alternatively, a Diels-Alder reaction is performed using an alkene, alkyne, or conjugated diene containing a substituent derived from the desired anionic group (a substituent capable of introducing the desired anionic group) to obtain an intermediate, and then the desired (BD1) component may be obtained by introducing an anion group of to obtain a precursor, and introducing a desired cation by a salt exchange reaction.
The conjugated diene is appropriately selected according to the target compound (component (BD1)), and for example, anthracene or its derivatives, triptycene or its derivatives may be used.
The method of introducing an anion group is, for example, a method using an esterification reaction; a method of combining an ammonium salt having an anion group introduced with a tosyl group and a lithium compound having a ring structure of an anion skeleton (derived from Diels-Alder reaction). Examples thereof include a method using a reaction, a method of obtaining a sulfonate by sulfinating an intermediate containing a halogen atom to obtain a sulfinate, and then oxidizing the sulfinate.

When an esterification reaction is used as a method for introducing an anionic group, for example, the compound represented by the general formula (bd1) [a compound having an anionic group represented by the general formula (bd1-r-an1), Y ^b01 = —C(=O)—O—] includes the production method of the embodiment including the first and second steps shown below.
Incidentally, the anion group represented by the general formula (bd1-r-an1) and Y ^b01 =-C(=O)-O- is represented by the general formula (b1-r-an10). anion group”. The target compound produced by the production method of the embodiment including the first and second steps is referred to as compound (B1-0).
Raw materials used in each step may be commercially available ones or synthesized ones.
The organic solvent used in steps 1 and 2 can dissolve the compounds used in each step and does not react with the compounds. Examples include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N, N -dimethylformamide, dimethylacetamide, dimethylsulfoxide, acetonitrile, propionitrile and the like.

- First step In the first step, the intermediate and compound (I) are dissolved in an organic solvent (eg, dichloromethane) and reacted in the presence of a base. After that, a precursor (Bpre) is obtained by performing filtration, concentration, and the like.

［式中、Ｒ^ｂ０１及びＶ^ｂ０１は、上記式（ｂｄ１－ｒ－ａｎ１）中のＲ^ｂ０１及びＶ^ｂ０１とそれぞれ同様である。（Ｍ_１”^ｍ＋）_１／ｍは、アンモニウムカチオンである。Ｒｘ^５、Ｒｘ^６、Ｒｚ^１～Ｒｚ^４、Ｒ^０２１、ｎ１、ｎ１１、Ｒ^０２２、ｎ２及びｎ２１は、上記式（ｂｄ１－ａｎ３）中のＲｘ^５、Ｒｘ^６、Ｒｚ^１～Ｒｚ^４、Ｒ^０２１、ｎ１、ｎ１１、Ｒ^０２２、ｎ２及びｎ２１とそれぞれ同様である。但し、Ｒｘ^５～Ｒｘ^６及びＲｚ^１～Ｒｚ^４のうち少なくとも１個は一般式（ｂ１－ｒ－ａｎ１０）で表されるアニオン基を有し、アニオン部全体でｎ価のアニオンとなる。ｎは１以上の整数である。］

[In the formula, R ^b01 and V ^b01 are the same as R ^b01 and V ^b01 in the above formula (bd1-r-an1), respectively. (M ₁ ″ ^m+ ) _1/m is an ammonium cation. Rx ⁵ , Rx ⁶ , Rz ¹ to Rz ⁴ , R ⁰²¹ , n1, n11, R ⁰²² , n2 and n21 are the are the same as Rx ⁵ , Rx ⁶ , Rz ¹ to Rz ⁴ , R ⁰²¹ , n1, n11, R ⁰²² , n2 and n21, respectively, provided that at least one of Rx ⁵ to Rx ⁶ and Rz ¹ to Rz ⁴ Each has an anion group represented by the general formula (b1-r-an10), and the entire anion portion becomes an n-valent anion, where n is an integer of 1 or more.]

Examples of bases added in the first step include organic bases such as triethylamine, 4-dimethylaminopyridine, pyridine, ethyldiisopropylaminocarbodiimide (EDCI) hydrochloride, dicyclohexylcarboximide (DCC), diisopropylcarbodiimide, and carbodiimidazole; Inorganic bases such as sodium hydride, K ₂ CO ₃ , Cs ₂ CO ₃ and the like are included.
The cation moiety of compound (I) may be an ammonium cation derived from an aliphatic amine or an ammonium cation derived from an aromatic amine.

The amount of compound (I) used is preferably about 1 to 3 equivalents, more preferably 1 to 2 equivalents, relative to the intermediate.
The reaction temperature is preferably 0 to 50°C, more preferably 5 to 40°C.

Second step In the second step, the precursor (Bpre) and the compound (II) for salt exchange are reacted in a solvent such as water, dichloromethane, acetonitrile, chloroform, etc. to obtain the precursor (Bpre) and the compound ( Salt exchange with an organic cation in II) gives the desired compound (B1-0).

［式中、Ｒ^ｂ０１及びＶ^ｂ０１は、上記式（ｂ１－ｒ－ａｎ１０）中のＲ^ｂ０１及びＶ^ｂ０１とそれぞれ同様である。（Ｍ_１”^ｍ＋）_１／ｍは、アンモニウムカチオンである。Ｒｘ^５、Ｒｘ^６、Ｒｚ^１～Ｒｚ^４、Ｒ^０２１、ｎ１、ｎ１１、Ｒ^０２２、ｎ２及びｎ２１は、上記式（ｂｄ１－ａｎ３）中のＲｘ^５、Ｒｘ^６、Ｒｚ^１～Ｒｚ^４、Ｒ^０２１、ｎ１、ｎ１１、Ｒ^０２２、ｎ２及びｎ２１とそれぞれ同様である。但し、Ｒｘ^５～Ｒｘ^６及びＲｚ^１～Ｒｚ^４のうち少なくとも１個は一般式（ｂ１－ｒ－ａｎ１０）で表されるアニオン基を有し、アニオン部全体でｎ価のアニオンとなる。ｎは１以上の整数である。Ｚ^－は、非求核性イオンである。（Ｍ^ｍ＋）_１／ｍは、ｍ価の有機カチオンであり、上記と同様である。］

[In the formula, R ^b01 and V ^b01 are the same as R ^b01 and V ^b01 in the above formula (b1-r-an10), respectively. (M ₁ ″ ^m+ ) _1/m is an ammonium cation. Rx ⁵ , Rx ⁶ , Rz ¹ to Rz ⁴ , R ⁰²¹ , n1, n11, R ⁰²² , n2 and n21 are the are the same as Rx ⁵ , Rx ⁶ , Rz ¹ to Rz ⁴ , R ⁰²¹ , n1, n11, R ⁰²² , n2 and n21, respectively, provided that at least one of Rx ⁵ to Rx ⁶ and Rz ¹ to Rz ⁴ Each has an anion group represented by the general formula (b1-r-an10), and the entire anion portion becomes an n-valent anion.n is an integer of 1 or more.Z ^- is a non-nucleophilic ion (M ^m+ ) _1/m is an m-valent organic cation and is the same as described above.]

^Z- is, for example, a halogen ion such as a bromide ion or a chloride ion; an ion that can become an acid with a lower acidity than the precursor (Bpre), _BF4- ^, _AsF6- ^, _SbF6- ^, _PF6- ^, or ClO; ₄ ^- and the like.
The reaction temperature is preferably about 0 to 100°C, more preferably about 0 to 50°C.
Although the reaction time varies depending on the reactivity of the precursor (Bpre) and the compound (II) for salt exchange, the reaction temperature, etc., it is usually preferably 10 minutes or more and 24 hours or less, more preferably 10 minutes or more and 12 hours or less. preferable.

After the salt exchange reaction is completed, the compound in the reaction solution may be isolated and purified. Conventionally known methods can be used for isolation and purification, and for example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography and the like can be used in combination as appropriate.
The structures of the compounds obtained as described above are determined by ¹ H-nuclear magnetic resonance (NMR) spectroscopy, ¹³ C-NMR spectroscopy, ¹⁹ F-NMR spectroscopy, infrared absorption (IR) spectroscopy, mass spectrometry (MS ) method, elemental analysis method, X-ray crystal diffraction method, and other general organic analysis methods.

The intermediate is appropriately selected according to the target compound (B1-0), and examples thereof include products by the Diels-Alder reaction represented by the following reaction formula. Anthracene or a derivative thereof can be used for (starting material 1) in the following reaction scheme. A compound having an ethylenic double bond, such as an acrylic acid ester, can be used as (starting material 2) in the following reaction formula.
Intermediates also include triptycene and derivatives thereof.

［式中、Ｒｘ_１’～Ｒｘ _４’は、前記Ｒｘ^１～Ｒｘ^４と同様である。Ｒｙ_１’～Ｒｙ_２’は、前記Ｒｙ^１～Ｒｙ^２と同様である。

は三重結合又は二重結合である。

は二重結合又は単結合である。Ｒｚ_１’～Ｒｚ_４’は、前記Ｒｚ^１～Ｒｚ^４と同様である。但し、Ｒｘ_１’～Ｒｘ_４’、Ｒｙ_１’～Ｒｙ_２’及びＲｚ_１’～Ｒｚ_４’のうち少なくとも１個は、前記アニオン基を導入し得る、脱離基を含む基である。］

[In the formula, Rx ₁ ′ to Rx ₄ ′ are the same as Rx ¹ to Rx ⁴ above. Ry ₁ ′ to Ry ₂ ′ are the same as Ry ¹ to Ry ² above.

is a triple or double bond.

is a double bond or a single bond. Rz ₁ ′ to Rz ₄ ′ are the same as Rz ¹ to Rz ⁴ above. However, at least one of Rx ₁ '-Rx ₄ ', Ry ₁ '-Ry ₂ ' and Rz ₁ '-Rz ₄ ' is a group containing a leaving group capable of introducing the anion group. ]

The group containing a leaving group into which an anion group can be introduced includes, for example, a halogen atom, a group containing a halogen atom, and a group having a dehydration-condensable substituent (hydroxy group, carboxy group, etc.).

When an esterification reaction is used as a method for introducing an anionic group, the group containing a leaving group includes a substituent capable of dehydration condensation. For example, the intermediate in the reaction formula shown in the first step preferably has a dehydration-condensable substituent (such as a hydroxyl group or a carboxyl group). In this first step, an esterification reaction is carried out to obtain a sulfonic acid ammonium salt as a precursor (Bpre).

As a method for introducing an anion group, when using a reaction between an ammonium salt having an anion group introduced with a tosyl group and a lithium compound having a ring structure of an anion moiety skeleton (derived from Diels-Alder reaction), the leaving group The group containing includes a halogen atom or a group containing a halogen atom, preferably a bromine atom. An intermediate containing a halogen atom (preferably a bromine atom) is converted to Li to form a Li compound, and then reacted with an ammonium salt having an anion group introduced with a tosyl group to obtain an ammonium sulfonate as a precursor.

As a method for introducing an anion group, when using a method of obtaining a sulfonate by sulfinating an intermediate containing a halogen atom to obtain a sulfinate and then oxidizing it to obtain a sulfonate, the group containing the leaving group is , a halogen atom, or a group containing a halogen atom, preferably a bromine atom. An intermediate containing a halogen atom (preferably a bromine atom) is converted to an ammonium sulfinate by using a sulfinating agent in the presence of an amine, and further reacted with an oxidizing agent to obtain the ammonium sulfonate as a precursor. .

The desired compound (component (BD1)) can be obtained by subjecting the precursor ammonium sulfonate to the above-described salt exchange in the second step.

<Optional component>
The resist composition of the present embodiment may further contain components (optional components) other than the component (A) and compound (BD1) (components (B1) and (D1)) described above.
Examples of such optional components include components (B2), (D2), (D3), (E), (F), and (S) shown below.

<<(B2) component>>
The resist composition of the present embodiment may contain an acid generator component (hereinafter referred to as "(B2) component") other than the above-described (B1) component within a range that does not impair the effects of the present invention.
The component (B2) is not particularly limited, and those hitherto proposed as acid generators for chemically amplified resist compositions can be used.
Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators; Acid generators: nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, disulfone-based acid generators and the like.

As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), represented by general formula (b-2) A compound (hereinafter also referred to as "(b-2) component") or a compound represented by general formula (b-3) (hereinafter also referred to as "(b-3) component") can be mentioned. The component (b-1) does not contain the compound corresponding to the component (B1) described above.

［式中、Ｒ^１０１、Ｒ^１０４～Ｒ^１０８はそれぞれ独立に、置換基を有してもよい環式基、置換基を有してもよい鎖状のアルキル基、又は置換基を有し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 , R ¹⁰⁴ to R ¹⁰⁸ are each independently an optionally substituted cyclic group, an optionally substituted chain alkyl group, or a substituted is a good chain alkenyl group. R ¹⁰⁴ and R ¹⁰⁵ may combine with each other to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ¹⁰¹ to V ¹⁰³ are each independently a single bond, an alkylene group or a fluorinated alkylene group. L ¹⁰¹ to L ¹⁰² are each independently a single bond or an oxygen atom. L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —. m is an integer of 1 or more, and ^M'm+ is an m-valent onium cation. ]

{anion part}
Anion portion of component (b-1) In formula (b-1), R ¹⁰¹ is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or a substituted It is a chain alkenyl group which may have a group. ^{The explanation of R 101 is as follows} : ^substitution A hydrocarbon group optionally having a group (a cyclic group optionally having a substituent, a chain alkyl group optionally having a substituent, or a chain alkenyl group optionally having a substituent group) is the same as the explanation for
Among them, R ¹⁰¹ is preferably an optionally substituted cyclic group, more preferably an optionally substituted cyclic hydrocarbon group. More specifically, a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane; -7); and -SO ₂ -containing cyclic groups represented by the above general formulas (a5-r-1) to (a5-r-4).

In formula (b-1) above, Y ¹⁰¹ is a divalent linking group containing a single bond or an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, said Y ¹⁰¹ may contain an atom other than an oxygen atom. Atoms other than an oxygen atom include, for example, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, and the like.
Such a divalent linking group containing an oxygen atom includes, for example, the linking groups represented by the above general formulas (y-al-1) to (y-al-8).
Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, represented by the above general formulas (y-al-1) to (y-al-5), respectively. is more preferred.

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

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

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

［式中、Ｒ”^１０１は、置換基を有してもよい脂肪族環式基、上記の化学式（ｒ－ｈｒ－１）～（ｒ－ｈｒ－６）でそれぞれ表される１価の複素環式基、又は置換基を有してもよい鎖状のアルキル基である。Ｒ”^１０２は、置換基を有してもよい脂肪族環式基、前記一般式（ａ２－ｒ－１）、（ａ２－ｒ－３）～（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－含有環式基である。Ｒ”^１０３は、置換基を有してもよい芳香族環式基、置換基を有してもよい脂肪族環式基、又は置換基を有してもよい鎖状のアルケニル基である。Ｖ”^１０１は、炭素数１～４のアルキレン基、又は炭素数１～４のフッ素化アルキレン基である。Ｒ^１０２は、フッ素原子又は炭素数１～５のフッ素化アルキル基である。ｖ”はそれぞれ独立に０～３の整数であり、ｑ”はそれぞれ独立に１～２０の整数であり、ｎ”は０または１である。］

[Wherein, R″ ¹⁰¹ is an optionally substituted aliphatic cyclic group, a monovalent heterocyclic group represented by each of the above chemical formulas (r-hr-1) to (r-hr-6) A cyclic group or an optionally substituted chain alkyl group. R″ ¹⁰² is an optionally substituted aliphatic cyclic group, the general formula (a2-r-1) , (a2-r-3) to (a2-r-7) respectively represented by a lactone-containing cyclic group, or the general formulas (a5-r-1) to (a5-r-4) respectively represented by is a —SO ₂ —containing cyclic group. R″ ¹⁰³ is an optionally substituted aromatic cyclic group, an optionally substituted aliphatic cyclic group, or an optionally substituted chain alkenyl group. V″ ¹⁰¹ is an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group having 1 to 4 carbon atoms. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Each v″ is independently an integer of 0 to 3, each q″ is independently an integer of 1 to 20, and n″ is 0 or 1.]

The optionally substituted aliphatic cyclic groups of R″ ¹⁰¹ , R″ ¹⁰² and R″ ¹⁰³ are exemplified as cyclic aliphatic hydrocarbon groups for Rx ¹ to Rx ⁴ etc. in the formula (bd1). Examples of the substituent include the same substituents that may substitute the cyclic aliphatic hydrocarbon group for Rx ¹ to Rx ⁴ and the like in the formula (bd1). .

The aromatic cyclic group which may have a substituent in R″ ¹⁰³ is the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in Rx ¹ to Rx ⁴ etc. in the formula (bd1). Examples of the substituent include the same substituents that may substitute the aromatic hydrocarbon group in Rx ¹ to Rx ⁴ and the like in the formula (bd1).

The chain alkyl group which may have a substituent in R″ ¹⁰¹ is preferably a group exemplified as the chain alkyl group for Rx ¹ to Rx ⁴ etc. in the formula (bd1).R″ The chain alkenyl group which may have a substituent in ¹⁰³ is preferably a group exemplified as the chain alkenyl group for Rx ¹ to Rx ⁴ etc. in the formula (bd1).

Anion portion of component (b-2) In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ are each independently an optionally substituted cyclic group and an optionally substituted chain. a linear alkyl group, or a chain alkenyl group which may have a substituent, and each of Rx ¹ to Rx ⁴ and the like in the formula (bd1) is a cyclic group which may have a substituent , an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group. In addition, R ¹⁰⁴ and R ¹⁰⁵ may combine with each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably a chain alkyl group which may have a substituent, and are a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. is more preferred.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. The chain alkyl groups of R ¹⁰⁴ and R ¹⁰⁵ preferably have a smaller number of carbon atoms within the range of the number of carbon atoms described above, for reasons such as good solubility in resist solvents. In addition, in the chain alkyl groups of R ¹⁰⁴ and R ¹⁰⁵ , the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, which is preferable. The proportion of fluorine atoms in the chain alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. is a perfluoroalkyl group.
In formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, each of which is the same as V ¹⁰¹ in formula (b-1) mentioned.
In formula (b-2), L ¹⁰¹ and L ¹⁰² are each independently a single bond or an oxygen atom.

Anion portion of component (b-3) In formula (b-3), R ¹⁰⁶ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain which may have a substituent a linear alkyl group, or a chain alkenyl group which may have a substituent, and each of Rx ¹ to Rx ⁴ and the like in the formula (bd1) is a cyclic group which may have a substituent , an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.
L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -.

{cation part}
In formulas (b-1), (b-2) and (b-3), m is an integer of 1 or more, and ^M'm+ is an m-valent onium cation. Suitable examples of M′ ^m+ include sulfonium cations and iodonium cations. 149), and the like.

M′ ^m+ in formulas (b-1), (b-2) and (b-3) includes diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, the above chemical formula (ca- 2-1) to (ca-2-2) respectively, cations represented by the above chemical formulas (ca-3-1) to (ca-3-7) respectively, the above chemical formula (ca- Cations represented by 4-1) to (ca-4-2) are also included.

Among the above, the cation moieties [(M′ ^m+ ) _1/m ] are represented by the chemical formulas (ca-1-1) to (ca-1-78), (ca-1-101) to (ca-1-149) are more preferred.

In the resist composition of this embodiment, the component (B2) may be used singly or in combination of two or more.
When the resist composition contains component (B2), the content of component (B2) in the resist composition is preferably 50 parts by mass or less, and 1 to 40 parts by mass, per 100 parts by mass of component (A). is more preferred, and 5 to 30 parts by mass is even more preferred.
When the resist composition contains the component (B2), the content of the component (B2) in the total acid generator component (B) that generates an acid acting on the component (A) in the resist composition is For example, it is 50% by mass or less, more preferably 30% by mass or less, and still more preferably 0% by mass or more and 5% by mass or less.
By setting the content of the component (B2) within the above range, pattern formation is sufficiently performed.

<<(D2) component>>
Component (D2) is a base component and is a photodegradable base that decomposes upon exposure to lose acid diffusion controllability (excluding those corresponding to component (D1) above).
By using the resist composition containing the component (D2), the contrast between the exposed portion and the unexposed portion of the resist film can be further improved when forming a resist pattern.

The component (D2) is not particularly limited as long as it is decomposed by exposure to light and loses the acid diffusion controllability. ), a compound represented by the following general formula (d2-2) (hereinafter referred to as “(d2-2) component”) and a compound represented by the following general formula (d2-3) (hereinafter referred to as “(d2- 3) One or more compounds selected from the group consisting of "components" are preferred.
Components (d2-1) to (d2-3) do not act as quenchers because they decompose in the exposed areas of the resist film and lose the acid diffusion controllability (basicity), and act as quenchers in the unexposed areas of the resist film. acts as

［式中、Ｒｄ^１～Ｒｄ^４は置換基を有してもよい環式基、置換基を有してもよい鎖状のアルキル基、又は置換基を有してもよい鎖状のアルケニル基である。但し、一般式（ｄ２－２）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が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価のオニウムカチオンである。］

[In the formula, Rd ¹ to Rd ⁴ are a cyclic group optionally having a substituent, a chain alkyl group optionally having a substituent, or a chain alkenyl group optionally having a substituent is. However, it is assumed that no fluorine atom is bonded to the carbon atom adjacent to the S atom in Rd ² in general formula (d2-2). Yd ¹ is a single bond or a divalent linking group. m is an integer of 1 or more, and each ^M'm+ is independently an m-valent onium cation. ]

{(d2-1) component}
Anion portion In formula (d2-1), Rd ¹ is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted It is a chain alkenyl group, and includes the same groups as Rx ¹ to Rx ⁴ in the formula (bd1).
Among these, Rd ¹ is an optionally substituted aromatic hydrocarbon group, an optionally substituted aliphatic cyclic group, or an optionally substituted chain-like Alkyl groups are preferred. Examples of substituents that these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, and general formulas (a2-r-1) to (a2-r-7). ), an ether bond, an ester bond, or a combination thereof. When it contains an ether bond or an ester bond as a substituent, it may be via an alkylene group, and the substituents in this case are represented by the above formulas (y-al-1) to (y-al-5), respectively. is preferred.
Preferred examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (for example, a polycyclic structure consisting of a ring structure of a bicyclooctane skeleton and a ring structure other than this). be done.
More preferably, the aliphatic cyclic group is a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, 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 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and other branched alkyl groups.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and 1 ~4 is more preferred. The fluorinated alkyl group may contain atoms other than fluorine atoms. Atoms other than a fluorine atom include, for example, an oxygen atom, a sulfur atom, a nitrogen atom, 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 the number of hydrogen atoms constituting the linear alkyl group is preferably A fluorinated alkyl group (straight-chain perfluoroalkyl group) in which all are substituted with fluorine atoms is particularly preferred.

Preferred specific examples of the anion portion of component (d2-1) are shown below.

Cation Moiety In formula (d2-1), M′ ^m+ is an m-valent onium cation.
The onium cation for M'm ⁺ can be appropriately selected from the same onium cations as those for M'm ⁺ in the above formulas (b-1) to (b-3) so as to be different from the component (D1).
Component (d2-1) may be used alone or in combination of two or more.

{(d2-2) component}
Anion portion In formula (d2-2), Rd ² is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted It is a chain alkenyl group and includes the same groups as Rx ¹ to Rx ⁴ in the formula (bd1).
However, the carbon atom adjacent to the S atom in Rd ² is not bonded to a fluorine atom (not fluorine-substituted). As a result, the anion of the component (d2-2) becomes a moderately weak acid anion, and the quenching ability of the component (D2) is improved.
Rd ² is preferably an optionally substituted chain alkyl group or an optionally substituted aliphatic cyclic group. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. Aliphatic cyclic groups include groups obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like (which may have substituents); is more preferably a group from which a hydrogen atom is removed.
^The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain and the same substituents as those that may be possessed by the alkyl group).

Preferred specific examples of the anion portion of component (d2-2) are shown below.

Cation Moiety In formula (d2-2), M′ ^m+ is an m-valent onium cation, which is the same as M′ ^m+ in formula (d2-1).
The component (d2-2) may be used singly or in combination of two or more.

{(d2-3) component}
Anion portion In formula (d2-3), Rd ³ is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain is a linear alkenyl group, and includes the same groups as Rx ¹ to Rx ⁴ in the formula (bd1), and is a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. is preferred. Among them, a fluorinated alkyl group is preferred, and the same fluorinated alkyl group as Rd ¹ is more preferred.

In formula (d2-3), Rd ⁴ is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain It is an alkenyl group and includes the same groups as Rx ¹ to Rx ⁴ in the formula (bd1).
Among them, an optionally substituted alkyl group, alkoxy group, alkenyl group, and cyclic group are preferred.
The alkyl group for Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group and an isobutyl group. , tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A portion of the hydrogen atoms of the alkyl group of ^Rd4 may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group for Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n- butoxy group and tert-butoxy group. Among them, a methoxy group and an ethoxy group are preferable.

Examples of the alkenyl group for Rd ⁴ include those similar to Rx ¹ to Rx ⁴ in the formula (bd1), and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group. preferable. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

Examples of the cyclic group for Rd ⁴ include those similar to Rx ¹ to Rx ⁴ in the formula (bd1), and cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and other cyclo An alicyclic group obtained by removing one or more hydrogen atoms from an alkane, 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 dissolves well in organic solvents, resulting in good lithography properties.

In formula (d2-3), Yd ¹ is a single bond or a divalent linking group.
The divalent linking group for Yd ¹ is not particularly limited, but may be a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) optionally having a substituent, a bivalent heteroatom-containing and the like. These are respectively the ^divalent hydrocarbon group optionally having a substituent, the bivalent heteroatom-containing divalent and the same as the linking group of
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, more preferably a methylene group or an ethylene group.

Preferred specific examples of the anion portion of component (d2-3) are shown below.

Cation Moiety In formula (d2-3), M′ ^m+ is an m-valent onium cation, which is the same as M′ ^m+ in formula (d2-1).
Component (d2-3) may be used alone or in combination of two or more.

As the component (D2), any one of the above components (d2-1) to (d2-3) may be used alone, or two or more of them 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 0.5 to 10 parts by mass and 0.5 to 10 parts by mass per 100 parts by mass of the component (A). 5 to 8 parts by mass is more preferable, and 1 to 6 parts by mass is even more preferable.
Further, when the resist composition contains the component (D2), among the entire base component (D) that traps (controls acid diffusion) the acid generated from the component (B) by exposure in the resist composition, ( The content of component D2) is, for example, 50% by mass or less, more preferably 30% by mass or less, and even more preferably 0% by mass or more and 5% by mass or less.
When the content of the component (D2) is at least the preferred lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained. On the other hand, if it is equal to or less than the upper limit, the balance with other components can be achieved, and various lithography properties will be improved.

Method for producing component (D2):
The method for producing the components (d2-1) and (d2-2) is not particularly limited, and they can be produced by known methods.
In addition, the method for producing component (d2-3) is not particularly limited, and for example, it is produced in the same manner as the method described in US2012-0149916.

<<(D3) component>>
The component (D3) is a base component and a nitrogen-containing organic compound component that acts as an acid diffusion control agent in the resist composition (excluding those corresponding to the above components (D1) and (D2)). is.

Component (D3) is not particularly limited as long as it acts as an acid diffusion control agent and does not correspond to components (D1) and (D2). compounds, aliphatic amines, and the like.

Compounds consisting of an anion moiety and a cation moiety in the component (D3) include those in which the cation moiety in the above components (d2-1) to (d2-3) is an ammonium cation. The ammonium cation here is NH ₄ ⁺ , or a cation in which H bound to the nitrogen atom is substituted with a hydrocarbon group which may have a heteroatom (primary to quaternary ammonium cation) or the nitrogen atom thereof. A cyclic cation that forms a ring with is mentioned.

Among the aliphatic amines, secondary aliphatic amines and tertiary aliphatic amines are preferred.
Aliphatic amines are amines having one or more aliphatic groups, which preferably have 1 to 12 carbon atoms.
Aliphatic amines include amines (alkylamines or alkylalcohol amines) in which at least one hydrogen atom of ammonia _NH3 is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms, or cyclic amines.
Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine and n-decylamine; - dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, trialkylamine; Alkyl alcohol amines such as isopropanolamine, di-n-octanolamine and tri-n-octanolamine are included. Among these, trialkylamines having 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

Cyclic amines include, for example, heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of aliphatic monocyclic amines include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable, and specifically, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5. 4.0]-7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane and the like.

Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2- (1-Methoxyethoxy)ethyl}amine, Tris{2-(1-ethoxyethoxy)ethyl}amine, Tris{2-(1-ethoxypropoxy)ethyl}amine, Tris[2-{2-(2-hydroxyethoxy) ) ethoxy}ethyl]amine, triethanolamine triacetate, etc., and triethanolamine triacetate is preferred.

Moreover, you may use an aromatic amine as a (D3) component.
Aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine and the like.

(D3) component may be used individually by 1 type, and may be used in combination of 2 or more type.
When the resist composition contains component (D3), component (D3) is usually used in the range of 0.01 to 5 parts by mass per 100 parts by mass of component (A). By setting the amount within the above range, the balance with other components can be achieved, and various lithography properties can be improved.

<<Component (E): At least one compound selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and derivatives thereof>>
The resist composition of the present embodiment contains an organic carboxylic acid and a phosphorus oxoacid and its derivatives as optional components for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, storage stability over time, and the like. At least one compound (E) selected from the group (hereinafter referred to as "(E) component") can be contained.
Suitable examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid.
Phosphorus oxoacids include phosphoric acid, phosphonic acid, phosphinic acid, etc. Among these, phosphonic acid is particularly preferred.
Examples of the oxoacid derivative of phosphorus include esters obtained by substituting a hydrogen atom of the above oxoacid with a hydrocarbon group. Examples of the hydrocarbon group include alkyl groups having 1 to 5 carbon atoms, 15 aryl groups and the like.
Derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Phosphonic acid derivatives include phosphonic acid esters such as dimethyl phosphonic acid, di-n-butyl phosphonic acid, phenylphosphonic acid, diphenyl phosphonic acid and dibenzyl phosphonic acid.
Phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.
In the resist composition of this embodiment, the component (E) may be used alone or in combination of two or more.
When the resist composition contains component (E), the content of component (E) is usually in the range of 0.01 to 5 parts by mass per 100 parts by mass of component (A).

<<(F) component: Fluorine additive component>>
The resist composition of the present embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") in order to impart water repellency to the resist film or improve lithography properties.
As the component (F), for example, JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, JP-A-2011-128226. can be used.
More specific examples of component (F) include polymers having a structural unit (f1) represented by the following formula (f1-1). Examples of this polymer include a polymer (homopolymer) consisting only of a structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1). it is preferably a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, as the structural unit (a1) to be copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, 1-methyl-1-adamantyl ( Structural units derived from meth)acrylates are preferred.

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

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

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

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms. , and 1 to 10 carbon atoms are particularly preferred.
In the hydrocarbon group containing a fluorine atom, 25% or more of the hydrogen atoms in the hydrocarbon group are preferably fluorinated, more preferably 50% or more are fluorinated, and 60% or more are Fluorination is particularly preferred because the hydrophobicity of the resist film during immersion exposure increases.
Among them, Rf ¹⁰¹ is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, such as a trifluoromethyl group, —CH ₂ —CF ₃ , —CH ₂ —CF ₂ —CF ₃ , —CH(CF ₃ ) ₂ , -CH ₂ -CH ₂ -CF ₃ , -CH ₂ -CH ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₃ are particularly preferred.

The mass-average molecular weight (Mw) of component (F) (polystyrene equivalent by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. When it is at most the upper limit of this range, it has sufficient solubility in a resist solvent for use as a resist, and when it is at least the lower limit of this range, the resist film has good water repellency.
The dispersity (Mw/Mn) of component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

In the resist composition of this embodiment, the component (F) may be used alone or in combination of two or more.
When the resist composition contains the (F) component, the content of the (F) component is usually used in a proportion of 0.5 to 10 parts by mass per 100 parts by mass of the (A) component.

<<(S) component: organic solvent 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").
As the component (S), any component that can dissolve each component to be used and form a uniform solution can be used. It can be selected and used.
Examples of 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, 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; Derivatives of polyhydric alcohols such as compounds having an ether bond such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether and other monoalkyl ethers or monophenyl ethers of compounds [among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate , methyl methoxypropionate, ethyl ethoxypropionate and other esters; anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, Aromatic organic solvents such as xylene, cymene and mesitylene, dimethylsulfoxide (DMSO) and the like can be mentioned.
In the resist composition of the present embodiment, the (S) component may be used singly or as a mixed solvent of two or more.
Among them, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.
A mixed solvent obtained by mixing PGMEA and a polar solvent is also preferable. The blending ratio (mass ratio) thereof may be appropriately determined in consideration of compatibility between PGMEA and the polar solvent, etc., preferably 1:9 to 9:1, more preferably 2:8 to 8:2. It is preferable to be within the range.
More specifically, when EL or cyclohexanone is blended as a polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. . Further, when PGME is blended as a polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, still more preferably 3:7 to 7: 3. Further, a mixed solvent of PGMEA, PGME and cyclohexanone is also preferred.
Further, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, as a mixing ratio, the mass ratio of the former to the latter is preferably 70:30 to 95:5.
The amount of the component (S) to be used is not particularly limited, and is appropriately set according to the coating film thickness at a concentration that can be applied to the substrate or the like. The component (S) is generally used so that the resist composition has a solid content concentration of 0.1 to 20 mass %, preferably 0.2 to 15 mass %.

The resist composition of the present invention further optionally contains miscible additives such as additional resins, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents to improve the performance of the resist film. , dyes, etc. can be added and contained as appropriate.

After dissolving the resist material in the (S) component, the resist composition of the present embodiment may be subjected to removal of impurities and the like using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter composed of a polyimide porous membrane, a filter composed of a polyamideimide porous membrane, a filter composed of a polyimide porous membrane and a polyamideimide porous membrane, or the like. Examples of the polyimide porous film and the polyamideimide porous film include those described in JP-A-2016-155121.

The resist composition of the present embodiment contains the above-mentioned (A1) component, (BD1) component, and optionally the above optional component.
For example, when the (BD1) component is used as the (B1) component, a resist composition containing the (A1) component, the (B1) component, and the (D2) component or (D3) component is suitable. For example, when the (BD1) component is used as the (D1) component, a resist composition containing the (A1) component, the (B2) component, and the (D1) component is suitable.
Furthermore, for example, when the (BD1) component is used as the (B1) component and the (D1) component, respectively, a resist composition containing the (A1) component, the (B1) component, and the (D1) component is preferred. mentioned.

The resist composition of this embodiment described above contains the resin component (A1) having the structural unit (a0) and the compound (BD1) represented by the general formula (bd1). The component (BD1) has a specific structure (a bulky structure) in which the anion portion is mainly composed of hydrocarbons, so that the hydrophobicity is relatively enhanced. Thereby, the compatibility between the compound (BD1) and the resin component (A1) is enhanced, and the acid diffusibility in the resist film is appropriately controlled. Furthermore, since the resin component (A1) has a specific structural unit (a0), by appropriately adjusting the solubility in the developer and increasing the adhesion to the substrate, the rectangularity of the cross-sectional shape of the resist pattern can be improved. can be improved. In addition, due to the synergistic effect of the compound (BD1) and the resin component (A1), the (BD1) component can be uniformly distributed within the resist film. Therefore, according to the resist composition of the embodiment, it is presumed that the lithography properties (roughness reduction, etc.) are further improved, and the rectangularity of the cross-sectional shape of the resist pattern is improved.

In addition, when the resist composition of the embodiment is used, the uniformity of the compound (BD1) in the formed resist film is increased, so that a good shape resist pattern with high resolution and reduced roughness can be easily formed.

(Resist pattern forming method)
A method for forming a resist pattern according to a second aspect of the present invention includes the steps of forming a resist film on a support using the resist composition of the above-described embodiment, exposing the resist film, and is a method comprising the step of developing the resist film to form a resist pattern.
One 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 is then baked (post-apply bake (PAB)) at a temperature of, for example, 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 to light through a mask having a predetermined pattern (mask pattern) using an exposure device such as an electron beam lithography device or an EUV exposure device, or an electron beam that does not pass through a mask pattern. After selective exposure such as drawing by direct irradiation of , bake (post-exposure bake (PEB)) treatment is performed at a temperature of 80 to 150° C. for 40 to 120 seconds, preferably 60 to 90 seconds.
Next, the resist film is developed. The developing process is carried out using an alkaline developer in the case of the alkali development process, and using a developer containing an organic solvent (organic developer) in the case of the solvent development process.
Rinsing treatment is preferably performed after the development treatment. As for the rinsing treatment, water rinsing using pure water is preferable in the case of the alkali developing process, and a rinsing solution containing an organic solvent is preferably used in the case of the solvent developing process.
In the case of the solvent development process, after the development processing or the rinsing processing, a processing for removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid may be performed.
After developing or rinsing, drying is performed. In some cases, baking treatment (post-baking) may be performed after the development treatment.
Thus, a resist pattern can be formed.

The support is not particularly limited, and a conventionally known one can be used. Examples thereof include a substrate for electronic parts and a substrate having a predetermined wiring pattern formed thereon. More specifically, silicon wafers, metal substrates such as copper, chromium, iron, and aluminum substrates, glass substrates, and the like can be used. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or 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. Inorganic films include inorganic antireflection coatings (inorganic BARC). Examples of organic films include organic antireflection coatings (organic BARC) and organic films such as a lower layer organic film in a multilayer resist method.
Here, the multi-layer resist method means that at least one layer of organic film (lower layer organic film) and at least one layer of 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 a lower layer organic film, and is said to be capable of forming a pattern with a high aspect ratio. That is, according to the multi-layer resist method, since the required thickness can be secured by the underlying organic film, the resist film can be made thinner, and fine patterns with 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 a method of forming one or more intermediate layers between the upper resist film and the lower organic film. (three-layer resist method) and a method of forming a multi-layered structure of three or more layers (metal thin film, etc.).

The wavelength used for exposure is not particularly limited, and includes ArF excimer laser, KrF excimer laser, _F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, soft X-rays, and the like. It can be done with radiation. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV, more highly useful for ArF excimer laser, EB or EUV, and more useful for EB or EUV. Especially expensive. That is, the resist pattern forming method of the present embodiment is a particularly useful method when the step of exposing the resist film includes an operation of exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam). .

The exposure method of the resist film may be normal exposure (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography.
In immersion exposure, the space between the resist film and the lowest lens of the exposure device is filled in advance with a solvent (immersion medium) having a refractive index greater than that of air, and exposure (immersion exposure) is performed in this state. exposure method.
As the liquid immersion medium, a solvent having a refractive index higher than that of air and lower than that 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 higher than that of air and lower than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents.
Specific examples _of fluorine-based inert liquids include fluorine _- based compounds such _{as C3HCl2F5} , _{C4F9OCH3 , C4F9OC2H5 , and C5H3F7 as} main _{components .} Examples include liquids, and those having a boiling point of 70 to 180°C are preferable, and those of 80 to 160°C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point within the above range because the medium used for liquid immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of perfluoroalkyl compounds include perfluoroalkyl ether compounds and perfluoroalkylamine compounds.
Further, specifically, the perfluoroalkyl ether compound includes perfluoro(2-butyl-tetrahydrofuran) (boiling point 102° C.), and the perfluoroalkylamine compound includes perfluorotributylamine ( boiling point 174°C).
Water is preferably used as the immersion medium from the viewpoints of cost, safety, environmental concerns, versatility, and the like.

Examples of the alkaline developer used for development processing in the alkaline development process include a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for development in the solvent development process may be any one capable of dissolving the component (A) (component (A) before exposure), and may be selected from known organic solvents. It can be selected as appropriate. Specific examples include polar solvents such as ketone-based solvents, ester-based solvents, alcohol-based solvents, nitrile-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents.
A ketone solvent is an organic solvent containing C--C(=O)--C in its structure. An ester solvent is an organic solvent containing C—C(=O)—O—C in its structure. An alcoholic solvent is an organic solvent containing an alcoholic hydroxyl group in its structure. "Alcoholic hydroxyl group" means a hydroxyl group attached to a carbon atom of an aliphatic hydrocarbon group. A nitrile-based solvent is an organic solvent containing a nitrile group in its structure. An amide-based solvent is an organic solvent containing an amide group in its structure. Ether-based solvents are organic solvents containing C—O—C in their structure.
Among organic solvents, there are also organic solvents that contain multiple types of functional groups that characterize the above solvents in their structures. shall be For example, diethylene glycol monomethyl ether corresponds to both alcohol-based solvents and ether-based solvents in the above classification.
The hydrocarbon-based solvent is a hydrocarbon solvent that is composed of an optionally halogenated hydrocarbon and has no substituents other than halogen atoms. A halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.
As the organic solvent contained in the organic developer, among the above, polar solvents are preferable, and ketone-based solvents, ester-based solvents, nitrile-based solvents, and the like are preferable.

Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, and methyl ethyl ketone. , methyl isobutyl ketone, acetylacetone, acetonyl acetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone) and the like. Among these, methyl amyl ketone (2-heptanone) is preferable as the ketone solvent.

Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, 2-methoxybutyl acetate , 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 2-ethoxybutyl Acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl Acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate , propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, 2-hydroxy methyl propionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate and the like. . Among these, butyl acetate is preferable as the ester solvent.

Nitrile solvents include, for example, acetonitrile, propionitrile, valeronitrile, butyronitrile and the like.

Known additives can be added to the organic developer as needed. Examples of such additives include surfactants. Although the surfactant is not particularly limited, for example, ionic or nonionic fluorine-based and/or silicon-based surfactants can be used. As the surfactant, a nonionic surfactant is preferable, and a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant is more preferable.
When a surfactant is blended, its blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.5% by mass, relative to the total amount of the organic developer. 5% by mass is more preferred.

The development treatment can be carried out by a known developing method, for example, a method of immersing the support in a developer for a certain period of time (dip method), or a method in which the developer is piled up on the surface of the support by surface tension and remains stationary for a certain period of time. method (paddle method), method of spraying the developer onto the surface of the support (spray method), and application of the developer while scanning the developer dispensing nozzle at a constant speed onto the support rotating at a constant speed. A continuous method (dynamic dispensing method) and the like can be mentioned.

As the organic solvent contained in the rinsing solution used for the rinsing treatment after the development treatment in the solvent development process, for example, among the organic solvents exemplified as the organic solvents used for the organic developer, one that hardly dissolves the resist pattern is appropriately selected. can be used as Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, alcohol-based solvents and amide-based solvents is preferable, and at least one selected from alcohol-based solvents and ester-based solvents is preferable. More preferred, alcoholic solvents are particularly preferred.
The alcohol-based solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. be done. Among these, 1-hexanol, 2-heptanol and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred.
Any one of these organic solvents may be used alone, or two or more thereof may be used in combination. Moreover, you may mix with organic solvents and water other than the above, and you may use it. However, considering development characteristics, the amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably 3% by mass, relative to the total amount of the rinse solution. The following are particularly preferred.
Known additives can be added to the rinse solution as needed. Examples of such additives include surfactants. Examples of surfactants include those mentioned above, preferably nonionic surfactants, more preferably nonionic fluorine-based surfactants or nonionic silicon-based surfactants.
When a surfactant is blended, its blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.5% by mass, relative to the total amount of the rinse liquid. % is more preferred.

Rinsing treatment (cleaning treatment) using a rinse liquid can be performed by a known rinsing method. Examples of the rinsing method include a method of continuously applying a rinse solution onto a support rotating at a constant speed (rotation coating method), a method of immersing a support in a rinse solution for a given period of time (dip method), A method of spraying a rinsing liquid onto the support surface (spray method) and the like can be mentioned.

In the method for forming a resist pattern of the present embodiment described above, since the resist composition according to the first aspect is used, when forming a resist pattern, good lithography properties (roughness reduction, etc.) are obtained. Moreover, it is possible to form a resist pattern in which the rectangularity of the cross-sectional shape of the pattern is improved.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
In this example, the compound represented by the chemical formula (1) is denoted as "compound (1)", and the compounds represented by other chemical formulas are similarly denoted.

<Synthesis Examples 1 to 10: Synthesis Examples of Copolymer (A1-1-1) to Copolymer (A1-1-7), Copolymer (A2-1) to Copolymer (A2-3)>
A copolymer was synthesized by radical polymerization using the compounds shown in Table 1 at a predetermined molar ratio.
For each obtained copolymer, the copolymer composition ratio of the polymer compound (ratio (molar ratio) of each structural unit in the polymer compound) determined by ¹³ C-NMR, standard polystyrene determined by GPC measurement Table 1 also shows the converted mass average molecular weight (Mw) and molecular weight dispersity (Mw/Mn).

Below, copolymers (A1-1-1) to copolymer (A1-1-7) obtained by the above synthesis examples, copolymers (A2-1) to copolymers (A2-3) indicates

The structural unit represented by the following chemical formula (a10-1), which constitutes the above copolymer, is a structural unit derived from the monomer represented by the above chemical formula (a10-1pre).

<Production of compound>
(Production example 1)
Anthracene (5.0 g, 28 mmol), methyl acrylate (3.6 g, 42 mmol), aluminum chloride (0.37 g, 2.8 mmol), and toluene (50 g) were added to a 100 mL three-necked flask and stirred. The mixture was reacted at 80° C. for 4 hours. After cooling, ultrapure water (50 g) and methyl tert-butyl ether (MTBE) (74 g) were added, and after stirring for 30 minutes, the aqueous layer was removed. The organic layer was washed with ultrapure water (50 g) three times and concentrated using a rotary evaporator. The concentrate was recrystallized with 2-isopropanol to give intermediate 1 (5.9 g, yield=79.6%).

Sodium hydroxide (3.8 g, 95 mmol) and ultrapure water (38 g) were added to a 100 mL three-necked flask, and after dissolution with stirring, intermediate 1 (5.0 g, 19 mmol) was dispersed. reacted over time. After cooling to room temperature, hydrochloric acid was added to neutralize the solution until it became acidic, then MTBE (50 g) was added, and after stirring for 30 minutes, the aqueous layer was removed. The organic layer was washed with ultrapure water (50 g) three times and the organic layer was concentrated using a rotary evaporator to give intermediate 2 (4.6 g, yield=97.2%).

Intermediate 2 (4.0 g, 16 mmol), compound (I-1) (6.0 g, 16 mmol), and dichloromethane (87 g) were added to a 100 mL three-necked flask and dissolved by stirring at room temperature. .
Next, diisopropylcarbodiimide (2.2 g, 18 mmol) and dimethylaminopyridine (0.098 g, 0.8 mmol) were added and reacted at room temperature for 5 hours. The reaction solution was filtered and the filtrate was concentrated using a rotary evaporator. After dissolving the concentrate in acetonitrile (17 g), it was added dropwise to MTBE (170 g), and the precipitated solid was filtered. The filter cake was again dissolved in acetonitrile (17 g), added dropwise to MTBE (170 g), and the precipitated solid was filtered. After repeating this operation twice, the filter cake was dried under reduced pressure to obtain a precursor (Bpre-1) (7.6 g, yield=78.2%).

(Production example 2)
A 300 mL pressure-resistant reaction vessel was charged with 4-bromo-3,3,4,4-tetrafluoro-1-butene (8.7 g, 42 mmol), anthracene (5.0 g, 28 mmol), and toluene (100 g). It was put in and reacted at 150° C. for 24 hours. Then, after cooling to room temperature, it was concentrated using a rotary evaporator. Methanol (50 g) was added to this concentrate and stirred, and the precipitated solid was filtered. Subsequent drying under reduced pressure gave intermediate 3 (6.0 g, yield=55.6%).

In a 200 mL three-neck flask, Intermediate 3 (5.8 g, 15 mmol), benzyltrimethylammonium chloride (2.9 g, 16 mmol), sodium dithionite (6.7, 38 mmol) and sodium bicarbonate (3.8 g). , 45 mmol), acetonitrile (16 g), and H ₂ O (16 g) were added and reacted at 65° C. for 4 hours while stirring. Next, after cooling to room temperature, the reaction solution was filtered, H ₂ O (16 g) and dichloromethane (25 g) were added to the filtrate, and after stirring for 30 minutes, the aqueous layer was removed. Next, it was washed twice with ultrapure water (160 g), and the organic layer was concentrated using a rotary evaporator. Acetonitrile (77 g) was added to the concentrate to dissolve it, 30% hydrogen peroxide solution (2.7 g, 24 mmol) was added, and the mixture was reacted at 45° C. for 7 hours. After cooling to room temperature, dichloromethane (78 g) and saturated aqueous sodium sulfite solution (78 g) were added, and after stirring with ultrapure water for 30 minutes, the aqueous layer was removed. After washing twice with ultrapure water (78 g), MTBE (156 g) was added and stirred for 30 minutes. The precipitate was filtered and dried under reduced pressure to give the precursor (Bpre-2) (5.8 g, yield=66.8%).

(Production example 3)
Intermediate 2 (4.0 g, 16 mmol), compound (I-2) (5.0 g, 16 mmol), and dichloromethane (87 g) were added to a 100 mL three-necked flask and dissolved by stirring at room temperature. . Next, diisopropylcarbodiimide (2.2 g, 18 mmol) and dimethylaminopyridine (0.098 g, 0.8 mmol) were added and reacted at room temperature for 5 hours. The reaction solution was filtered and the filtrate was concentrated using a rotary evaporator. After dissolving the concentrate in acetonitrile (17 g), it was added dropwise to MTBE (170 g), and the precipitated solid was filtered. The filter cake was again dissolved in acetonitrile (17 g), added dropwise to MTBE (170 g), and the precipitated solid was filtered. After repeating this operation twice, the filter cake was dried under reduced pressure to obtain a precursor (Bpre-3) (5.8 g, yield=66.8%).

(Production example 4)
Intermediate 4 was obtained (6.4 g, Yield = 82.3%).

Intermediate 4 (6.0 g, 22 mmol), 5-hydroxynorbornane 2,6-lactone (4.0 g, 26 mmol), and dichloromethane (120 g) were added to a 100 mL three-necked flask and dissolved by stirring at room temperature. rice field. Next, dimethylaminopyridine (0.13 g, 1 mmol) and triethylamine (5.5 g, 54 mmol) were added and reacted at room temperature for 24 hours. After adding ultrapure water (120 g) and stirring, hydrochloric acid was added until the water layer became acidic for neutralization, and after further stirring for 30 minutes, the water layer was removed. The organic layer was washed with ultrapure water (120 g) three times and the organic layer was concentrated using a rotary evaporator to give intermediate 5 (7.2 g, yield=77.1%).

Precursor (Bpre-4) was prepared in the same manner as in the preparation example of precursor (Bpre-1), except that intermediate 2 (4.0 g, 16 mmol) was changed to intermediate 5 (6.8 g, 16 mmol). (6.6 g, yield=53.1%).

(Production example 5)
Sodium hydroxide (3.6 g, 90 mmol) and ultrapure water (36 g) were added to a 100 mL three-necked flask, and after dissolution with stirring, intermediate 1 (4.8 g, 18 mmol) was dispersed. reacted over time. After cooling to room temperature, 20% hydrochloric acid (13.2 g, 72.4 mmol) and benzyltrimethylammonium chloride (5.0 g, 27 mmol) were added, then MTBE (50 g) was added and after stirring for 30 minutes, the aqueous layer was removed. bottom. The organic layer was washed with ultrapure water (50 g) three times, and the organic layer was concentrated using a rotary evaporator to give the precursor (Bpre-5) (5.7 g, yield = 71.0% ).

(Production example 6)
Sodium hydroxide (3.6 g, 90 mmol) and ultrapure water (36 g) were added to a 100 mL three-necked flask, and after dissolution with stirring, intermediate 4 (5.0 g, 18 mmol) was dispersed. reacted over time. After cooling to room temperature, 20% hydrochloric acid (13.2 g, 72.4 mmol) and benzyltrimethylammonium chloride (5.0 g, 27 mmol) were added, then MTBE (50 g) was added and after stirring for 30 minutes, the aqueous layer was removed. bottom. The organic layer was washed with ultrapure water (50 g) three times, and the organic layer was concentrated using a rotary evaporator,
The precursor (Bpre-6) was obtained (5.7 g, yield=71.0%).

(Production example of compound (B1-1))
Precursor (Bpre-1) (15.0 g, 24.7 mmol) and salt exchange compound A (7.4 g, 24.7 mmol) were dissolved in dichloromethane (100 g), ultrapure water (35 g) was added, The reaction was allowed to proceed for 30 minutes at room temperature. After completion of the reaction, the aqueous phase was removed, and the organic phase was washed four times with ultrapure water (35 g). The organic phase was concentrated to dryness using a rotary evaporator to give compound (B1-1) (16.5 g, yield=92.5%).

(Manufacturing examples of other compounds)
Except for changing the combination of the precursors (Bpre-1) to (Bpre-6) and the compound A for salt exchange, the same procedure as in the above "Production example of compound (B1-1)" was performed. Thus, compounds (B1-1) to (B1-4), compound (D1-1), and compound (D1-2) shown below were obtained.

Each compound obtained was subjected to NMR measurement, and the structure was identified from the following analysis results.

Compound (B1-1): combination of precursor (Bpre-1) and compound A for salt exchange
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 7.74-7.90 (m, 15H, ArH), 7.01-7.47 (m, ArH, 8H), 4.72 (s, CH, 1H), 4.43 (S, CH, 1H), 4.23, (t, CH2, 2H), 2.95-3.02(m, CH, 1H), 2.63-2.73, (m, CF2CH2, 2H), 1.86-2.07 (m, CH2, 2H)
¹⁹ F-NMR (DMSO, 376 MHz): δ (ppm) = -111.3, -117.4

Compound (B1-2): combination of precursor (Bpre-2) and compound A for salt exchange
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 7.74-7.90 (m, 15H, ArH), 7.00-7.48 (m, ArH, 8H), 4.70 (s, CH, 1H), 4.40 (s, CH, 1H), 3.15-3.22 (m, CF2CH, 1H), 1.95-2.15 (m, CH2, 2H)
¹⁹ F-NMR (DMSO, 376 MHz): δ (ppm) = -111.3, -117.4

Compound (B1-3): combination of precursor (Bpre-3) and compound A for salt exchange
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 7.74-7.90 (m, 15H, ArH), 7.00-7.48 (m, ArH, 8H), 4.70 (s, CH, 1H), 4.31-4.58 ( m, CH, CF2CH2, 3H), 2.95-3.02 (m, CH, 1H), 1.85-2.05 (m, CH2, 2H)
¹⁹ F-NMR (DMSO, 376 MHz): δ (ppm) = -111.4

Compound (B1-4): combination of precursor (Bpre-4) and compound A for salt exchange
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 7.74-7.90 (m, 15H, ArH), 7.01-7.47 (m, ArH, 8H), 4.70 (d, OCH(lactone), 1H), 4.58 (t, COOCH(lactone), 1H), 4.50(d, CH, 2H), 4.22, (t, COOCH2, 2H), 3.32(m, CH(lactone), 1H), 3.20(t, COCH, 2H) , 2.63-2.73, (m, CF2CH2,CH(lactone)4H), 1.60-2.20(m,CH2(lactone),4H)
¹⁹ F-NMR (DMSO, 376 MHz): δ (ppm) = -111.3, -117.4

Compound (D1-1): combination of precursor (Bpre-5) and compound A for salt exchange
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = ¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 7.74-7.90 (m, ArH, 15H), 7.00-7.48 (m, ArH, 8H ), 4.68(s, CH, 1H), 4.41(s, CH, 1H) , 2.95-3.02 (m, CH, 1H), 1.86-2.04 (m, CH2, 2H)

Compound (D1-2): combination of precursor (Bpre-6) and compound A for salt exchange
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = ¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 7.74-7.90 (m, ArH, 15H), 7.00-7.48 (m, ArH, 8H ), 4.85 (s, ArCH, 2H), 3.16 (s, CH, 2H)

<Preparation of resist composition>
(Examples 1 to 33, Comparative Examples 1 to 17)
Each component shown in Tables 2 to 4 was mixed and dissolved to prepare a resist composition of each example.

In Tables 2 to 4, each abbreviation has the following meaning. The numbers in [ ] are the compounding amounts (parts by mass).
(A1)-1 to (A1)-7: the above copolymers (A1-1-1) to (A1-1-7).
(A2)-1 to (A2)-3: the above copolymers (A2-1) to (A2-3).
(B1)-1 to (B1)-4: Acid generators comprising compounds represented by the above chemical formulas (B1-1) to (B1-4), respectively.
(D1)-1, (D1)-2: Acid diffusion control agents comprising compounds represented by the above chemical formulas (D1-1) and (D1-2), respectively.

(B2)-1, (B2)-2: Acid generators comprising compounds represented by the following chemical formulas (B2-1) and (B2-2), respectively.
(D2)-1: Acid diffusion control agent comprising a compound represented by the following chemical formula (D2-1).
(S)-1: Mixed solvent of propylene glycol monomethyl ether acetate/propylene glycol monomethyl ether=60/40 (mass ratio).

<Formation of resist pattern>
The resist composition of each example was applied onto an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS) using a spinner, and prebaked (PAB) on a hot plate at a temperature of 110° C. for 60 seconds. A resist film having a film thickness of 50 nm was formed by performing treatment and drying.
Next, the resist film is subjected to a 1:1 line-and-space pattern (hereinafter referred to as " LS pattern”) was drawn (exposure). After that, a post-exposure bake (PEB) treatment was performed at 100° C. for 60 seconds.
Next, alkaline development was performed at 23° C. for 60 seconds using a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.).
After that, water rinsing was performed for 15 seconds using pure water.
As a result, a 1:1 LS pattern with a line width of 50 nm was formed.

[Evaluation of optimum exposure (Eop)]
An optimum exposure dose Eop (μC/cm ² ) for forming an LS pattern of a target size was obtained by the resist pattern forming method described above. This is shown in Tables 5-7 as "Eop (μC/cm ² )".

[Evaluation of LWR (linewise roughness)]
For the LS pattern formed in <Formation of resist pattern>, 3σ, which is a scale indicating LWR, was obtained. This is shown in Tables 5 to 7 as "LWR (nm)".
"3σ" is a scanning electron microscope (accelerating voltage 800 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation), measuring 400 line positions in the longitudinal direction of the line, and the standard deviation obtained from the measurement results. (3σ) (unit: nm).
The smaller the value of 3σ, the smaller the roughness of the line sidewalls, which means that the LS pattern with a more uniform width was obtained.

[Evaluation of LS pattern shape]
The cross-sectional shape of the LS pattern formed in <Formation of resist pattern> is observed by SEM (scanning electron microscope, applied voltage 8 kV, product name: SU-8000, manufactured by Hitachi High Technology), and the upper part of the resist pattern A line width (Lt) and an intermediate line width (Lm) were measured. The closer the value of Lt/Lm to 1, the better the rectangularity of the cross-sectional shape. The rectangularity of the cross-sectional shape is "A: particularly good" when 0.95 ≤ (Lt / Lm) ≤ 1.05, 0.90 ≤ (Lt / Lm) < 0.95, or 1.05 < (Lt / Lm) ≤ 1.10 is evaluated as "B: good", (Lt / Lm) < 0.90 or 1.10 < (Lt / Lm) is evaluated as "C: poor" bottom.

From the results shown in Tables 5 to 7, it can be confirmed that according to the resist compositions of the examples to which the present invention is applied, a resist pattern having a good shape with reduced roughness can be formed.

Claims (17)

A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid,
containing a resin component whose solubility in a developer changes under the action of an acid, and a compound (BD1) consisting of an anion moiety and a cation moiety represented by the following general formula (bd1),
A resist composition, wherein the resin component has a structural unit (a0) containing a partial structure represented by the following general formula (a0-n-1).

[In the formula, R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms. R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. * indicates a bond. ]

[In the formula, Rx ¹ to Rx ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or two or more of them combine to form a ring structure; good too. Ry ¹ to Ry ² each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure.

is a double bond or a single bond. Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have However, at least one of Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the entire anion part becomes an n-valent anion. n is an integer of 1 or more. m is an integer of 1 or more, and M ^m+ represents an m-valent organic cation. ] The structural unit (a0) is a structural unit (a0-1) in which the polymerizable group at the W ¹ site is converted to the main chain in a compound represented by the following general formula (a0-1), or the following general formula ( 2. The resist composition according to claim 1, wherein the structural unit (a0-2) in the compound represented by a0-2) is obtained by converting the polymerizable group at the ^W2 site into a main chain.

[In the formula, R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms. R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. W ¹ and W ² are polymerizable group-containing groups. Y _a01 ^x0 is a single bond or a (n _a01 +1)-valent linking group. Y _a01 ^x0 and W ¹ may form a condensed ring. Y _a02 ^x0 is a single bond or a (n _a02 +1)-valent linking group. n _a01 and n _a02 are integers of 1-3. ] The structural unit (a0) is a structural unit (a0-1-1) in which the polymerizable group at the ^W1 site is converted to the main chain in the compound represented by the general formula (a0-1-1) below. 3. The resist composition of claim 1 or 2.

[In the formula, R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms. R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. ^W1 is a polymerizable group-containing group. Y _a01 ^x1 is a single bond or a divalent linking group. Y _a01 ^x2 is a (n _a01 +1)-valent aromatic hydrocarbon group which may have a substituent. W ¹ and Y _a01 ^x1 may form a condensed ring, and W ¹ and Y _a01 ^x1 and Y _a01 ^x2 may form a condensed ring. n _a01 is an integer of 1-3. ] 4. The resist composition according to any one of claims 1 to 3, wherein said R ² is an organic group having 1 to 12 carbon atoms and having a fluorine atom. 5. The resist composition of any one of claims 1 to 4, wherein said ^R1 and ^R2 are trifluoromethyl groups. The resist composition according to any one of claims 1 to 5, wherein the ratio of the structural unit (a0) is 10 to 80 mol% with respect to all structural units (100 mol%) constituting the resin component. thing. 7. The invention according to any one of claims 1 to 6, wherein at least one of Rx ¹ to Rx ² and at least one of Rx ³ to Rx ⁴ are bonded to each other to form a ring structure. resist composition. 8. The resist composition according to claim 1, wherein the anion moiety in the compound (BD1) is an anion represented by the following general formula (bd1-an1).

[In the formula, Rx ⁵ to Rx ⁶ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom. Rx ⁷ to Rx ⁸ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure. p is 1 or 2, and when p=2, a plurality of Rx ⁷ to Rx ⁸ may be different from each other. Ry ¹ to Ry ² each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure.

is a double bond or a single bond. Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have However, at least one of Rx ¹ to Rx ⁴ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the entire anion part becomes an n-valent anion. n is an integer of 1 or more. ] 9. The resist composition according to claim 8, wherein the anion moiety in said compound (BD1) is an anion represented by the following general formula (bd1-an2).

[In the formula, Rx ⁵ to Rx ⁶ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom. A plurality of Rx ⁷ to Rx ⁸ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or two or more of them may bond together to form a ring structure. . Ry ¹ to Ry ² each independently represent an optionally substituted hydrocarbon group or a hydrogen atom, or may combine with each other to form a ring structure.

is a double bond or a single bond. Rz ¹ to Rz ⁴ each independently represent an optionally substituted hydrocarbon group or a hydrogen atom if the valence permits, or two or more of them combine to form a ring structure You may have However, at least one of Rx ⁵ to Rx ⁸ , Ry ¹ to Ry ² and Rz ¹ to Rz ⁴ has an anion group, and the entire anion part becomes an n-valent anion. n is an integer of 1 or more. ] 10. The resist composition according to claim 8, wherein said Rx ⁷ to Rx ⁸ are mutually bonded to form a ring structure. 11. The resist composition according to any one of claims 8 to 10, wherein at least one of ^Rx5 to ^Rx6 has an anionic group. 12. The resist composition according to any one of claims 1 to 11, wherein said Ry ¹ to Ry ² are mutually bonded to form a ring structure. 13. The resist composition according to claim 1, wherein two or more of said Rz ¹ to Rz ⁴ are bonded to each other to form a ring structure. 14. The resist composition according to claim 1, wherein at least one of Rz ¹ to Rz ⁴ has an anionic group. The resist composition according to any one of claims 1 to 14, wherein the cation moiety in the compound (BD1) is a cation represented by any one of the following general formulas (ca-1) to (ca-4): thing.

[wherein R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² are each independently an aryl group optionally having a substituent, an alkyl group optionally having a substituent, or represents a good alkenyl group. Each of R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ and R ²¹¹ to R ²¹² may be mutually bonded to form a ring together with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, or may combine with each other to form a ring together with the sulfur atom in the formula. R ²¹⁰ is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ₂ — It contains cyclic groups. L ²⁰¹ represents -C(=O)- or -C(=O)-O-. A plurality of Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group. x is 1 or 2; W ²⁰¹ represents a (x+1)-valent linking group. ] Forming a resist film on a support using the resist composition according to any one of claims 1 to 15, exposing the resist film, and developing the resist film after exposure A method of forming a resist pattern, comprising the step of forming a resist pattern. 17. The method of forming a resist pattern according to claim 16, wherein in the step of exposing the resist film, the resist film is exposed to EUV (extreme ultraviolet) or EB (electron beam).