JP2013080245A - Resist composition, method for forming resist pattern, compound and acid generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acid generator useful for a resist composition, a resist composition containing the acid generator, and a method for forming a resist pattern using the resist composition.SOLUTION: A resist composition includes a base component (A) whose solubility in an alkali developer changes by an action of an acid and an acid generator component (B) generating an acid by exposure, where the acid generator component (B) comprises an acid generator (B1) made of a compound represented by the general formula (b1-11). In the formula (b1-11), Rto Rare each independently an alkyl group or an alkoxy group, n1 is an integer of 1 to 5, and n3 and n4 are each independently an integer of 0 to 3. Xis an anion.

Description

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

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film. A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. Further, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.

  Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist containing a base resin whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. For example, a positive chemically amplified resist contains, as a base resin, a resin that increases solubility in an alkaline developer by the action of an acid and an acid generator. When the acid is generated, the exposed portion becomes soluble in the alkaline developer.

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

A wide variety of acid generators used in chemically amplified resists have been proposed. For example, onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, diazomethane series, and the like. Acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like are known.
At present, as onium salt acid generators, those having a sulfonium ion such as triphenylsulfonium in the cation portion are mainly used. As the anion moiety of the onium salt acid generator, alkyl sulfonate ions or fluorinated alkyl sulfonate ions in which part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms are generally used. (For example, refer to Patent Document 2).
When such an onium salt-based acid generator is used, in order to suppress acid diffusion in the resist film after exposure, it is considered preferable that the length of the alkyl group or fluorinated alkyl group in the anion portion is longer. . However, an alkyl group having 6 or more carbon atoms or a fluorinated alkyl group is hardly decomposable, and the anion moiety may be one having 4 or less carbon atoms, for example, nonafluoro for safety in consideration of bioaccumulation. Butane sulfonate ions and the like are used.
Recently, an onium salt acid generator having a cationic structure and a substituent containing a bulky group such as tri (4-tert-butylphenyl) sulfonium has been proposed (for example, Patent Document 3).

JP 2003-241385 A Japanese Patent Laid-Open No. 2005-37888 JP 2006-18071 A

As mentioned above, acid generators with bulky substituents introduced have relatively high hydrophobicity, so they have excellent affinity with resist base materials and solubility in organic solvents, contributing to improved lithography properties. I think that.
However, the higher the hydrophobicity, the worse the solubility in an alkaline developer.If the solubility of an acid generator in an alkaline developer becomes poor, the acid generator does not dissolve sufficiently during development, causing problems such as defects and pattern tailing. May cause. Defects are, for example, general defects detected when a developed resist pattern is observed from directly above with a surface defect observation apparatus (trade name “KLA”) manufactured by KLA Tencor. Examples of the defects include scum, bubbles, dust, bridges between resist patterns, uneven color, and precipitates after development.
Therefore, there is a need for a novel compound that can achieve both excellent developer solubility and good lithography properties and is useful as an acid generator for resist compositions.
The present invention has been made in view of the above circumstances, and is a novel compound useful as an acid generator for a resist composition, an acid generator comprising the compound, a resist composition containing the acid generator, and An object of the present invention is to provide a resist pattern forming method using the resist composition.

In order to achieve the above object, the present invention employs the following configuration.
That is, the first aspect of the present invention is a resist composition containing a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure. In the resist composition, the acid generator component (B) includes an acid generator (B1) composed of a compound represented by the following general formula (b1-11).

［式中、Ｒ^１０１〜Ｒ^１０４はそれぞれ独立にアルキル基またはアルコキシ基であり、ｎ１は１〜５の整数であり、ｎ３およびｎ４はそれぞれ独立に０〜３の整数である。Ｘ⁻はアニオンである。］

[Wherein, R ^{101 to} R ¹⁰⁴ are each independently an alkyl group or an alkoxy group, n1 is an integer of 1 to 5, and n3 and n4 are each independently an integer of 0 to 3. X ⁻ is an anion. ]

According to a second aspect of the present invention, there is provided a step of forming a resist film on a support using the resist composition of the first aspect, a step of exposing the resist film, and an alkali development of the resist film. A resist pattern forming method including a step of forming a resist pattern.
A third aspect of the present invention is a compound represented by the following general formula (b1-11).

［式中、Ｒ^１０１〜Ｒ^１０４はそれぞれ独立にアルキル基またはアルコキシ基であり、ｎ１は１〜５の整数であり、ｎ３およびｎ４はそれぞれ独立に０〜３の整数である。Ｘ⁻はアニオンである。］

[Wherein, R ^{101 to} R ¹⁰⁴ are each independently an alkyl group or an alkoxy group, n1 is an integer of 1 to 5, and n3 and n4 are each independently an integer of 0 to 3. X ⁻ is an anion. ]

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

In the present specification and claims, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups.
The “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
“Structural unit” means a monomer unit (monomer unit) constituting a resin component (polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, a novel compound useful as an acid generator for a resist composition, an acid generator comprising the compound, a resist composition containing the acid generator, and resist pattern formation using the resist composition Can provide a method.

≪Resist composition≫
The resist composition of the present invention comprises a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid (hereinafter referred to as “component (A)”), and an acid generator component that generates an acid upon exposure ( B) (hereinafter referred to as component (B)).
In such a resist composition, when an acid is generated from the component (B) by exposure, the solubility of the component (A) in an alkaline developer is changed by the action of the acid. Therefore, in the formation of the resist pattern, when the resist film formed using the resist composition is selectively exposed, the solubility of the exposed part in the alkaline developer changes, while the alkaline developer in the unexposed part. The solubility in is not changed. Therefore, a resist pattern is formed by alkali developing this.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
The organic compound having a molecular weight of 500 or more used as the base material component is roughly classified into a non-polymer and a polymer. As the non-polymer, one having a molecular weight of 500 or more and less than 4000 (hereinafter referred to as a low molecular compound) is usually used. As the polymer, one having a molecular weight of 2000 or more (hereinafter referred to as a resin) is usually used. In the case of a resin, as the “molecular weight”, a mass average molecular weight in terms of polystyrene by GPC (gel permeation chromatography) is used. Hereinafter, the term “resin” refers to a polymer having a molecular weight of 2000 or more.
As the component (A), a resin whose alkali solubility is changed by the action of an acid may be used, a low molecular compound whose alkali solubility is changed by the action of an acid may be used, or these may be used in combination. .

When the resist composition of the present invention is a negative resist composition, as the component (A), a base component that is soluble in an alkali developer is used, and a crosslinking agent is further added to the negative resist composition. .
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause crosslinking between the base material component and the crosslinking agent, resulting in poor solubility in an alkali developer. To do. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the negative resist composition on the substrate is selectively exposed, the exposed portion turns into poorly soluble in an alkaline developer, while unexposed. Since the portion remains soluble in the alkali developer and does not change, a resist pattern can be formed by alkali development.
As the base component of the negative resist composition, a resin that is soluble in an alkali developer (hereinafter referred to as an alkali-soluble resin) is usually used.
As the alkali-soluble resin, a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or a lower alkyl ester of α- (hydroxyalkyl) acrylic acid is a good resist with little swelling. A pattern can be formed, which is preferable. Α- (Hydroxyalkyl) acrylic acid includes acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.
As the crosslinking agent, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of the present invention is a positive resist composition, as the component (A), a base material component whose solubility in an alkaline developer is increased by the action of an acid is used. The substrate component is hardly soluble in an alkali developer before exposure, and when an acid is generated from the component (B) by exposure, the solubility in the alkali developer is increased by the action of the acid. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the positive resist composition on the substrate is selectively exposed, the exposed portion changes from poorly soluble to soluble in an alkaline developer. On the other hand, since the unexposed portion remains hardly soluble in alkali and does not change, a resist pattern can be formed by alkali development.
The resist composition of the present invention is preferably a positive resist composition. That is, in the resist composition of the present invention, the component (A) is preferably a base material component whose solubility in an alkaline developer is increased by the action of an acid.
The component (A) may be a resin component (hereinafter also referred to as the component (A1)) whose solubility in an alkali developer is increased by the action of an acid, and is dissolved in an alkali developer by the action of an acid. It may be a low molecular compound (hereinafter sometimes referred to as the component (A2)) whose properties increase, or a mixture thereof.

[(A1) component]
As the component (A1), resin components (base resins) that are usually used as base components for chemically amplified resists can be used alone or in combination of two or more.
In the present invention, the component (A1) preferably contains a structural unit derived from an acrylate ester.
Here, in the present specification and claims, the “structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include those in which a hydrogen atom is bonded to the carbon atom at the α-position, and those in which a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom in the α-position. Include concepts. Examples of the substituent include a lower alkyl group and a halogenated lower alkyl group. Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
In the acrylate ester, as the lower alkyl group as a substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, Examples include lower linear or branched alkyl groups such as isopentyl group and neopentyl group.
Specific examples of the halogenated lower alkyl group include groups in which part or all of the hydrogen atoms in the above-mentioned “lower alkyl group as a substituent at the α-position” are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and is a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group. In view of industrial availability, a hydrogen atom or a methyl group is most preferable.

The component (A1) particularly preferably has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
In addition to the structural unit (a1), the polymer preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
In addition to the structural unit (a1) or in addition to the structural units (a1) and (a2), the polymer may be derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group. It is preferable to have a unit (a3).
Moreover, this polymer may have other structural units (a4) other than the said structural units (a1)-(a3).

-Structural unit (a1):
The structural unit (a1) is a structural unit derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire component (A1) difficult to dissolve in an alkali developer before dissociation, and dissociates with an acid. This increases the solubility of the entire component in an alkaline developer. The acid dissociable, dissolution inhibiting group is not particularly limited, and those that have been proposed as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists can be used. Generally, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. . Here, “(meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.
The “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O) —O— ), The tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom. In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom. The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.

Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.
“Aliphatic branched” means having a branched structure having no aromaticity. The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
Examples of the aliphatic branched acid dissociable, dissolution inhibiting group include a group represented by -C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ). ^Wherein, R 71 ^{to R 73} each independently represents a linear alkyl group of 1 to 5 carbon atoms. The group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ) preferably has 4 to 8 carbon atoms, specifically a tert-butyl group or a 2-methyl-2-butyl group. , 2-methyl-2-pentyl group, 3-methyl-3-pentyl group and the like. A tert-butyl group is particularly preferable.

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
In the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group, the aliphatic cyclic group may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The aliphatic cyclic group may be a hydrocarbon group (alicyclic group) composed of carbon and hydrogen, and some of the carbon atoms constituting the ring of the alicyclic group are oxygen atoms, nitrogen atoms, sulfur. It may be a heterocyclic group substituted with a heteroatom such as an atom. As the aliphatic cyclic group, an alicyclic group is preferable.
The aliphatic cyclic group may be either saturated or unsaturated, but is preferably saturated because it is highly transparent to ArF excimer laser and the like, and has excellent resolution and depth of focus (DOF). .
It is preferable that carbon number of an aliphatic cyclic group is 5-15.
Specific examples of monocyclic alicyclic groups include groups in which one or more hydrogen atoms have been removed from cycloalkane. More specifically, a group in which one or more hydrogen atoms have been removed from cyclopentane or cyclohexane can be mentioned, and a group in which two hydrogen atoms have been removed from cyclohexane is preferred.
Specific examples of the polycyclic alicyclic group include groups in which one or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane, or the like. More specifically, a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane can be used. Of these, groups in which two hydrogen atoms have been removed from adamantane, norbornane, and tetracyclododecane are preferred because they are easily available in the industry. Of these, a group in which two hydrogen atoms have been removed from adamantane or norbornane is preferable.

Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include: (i) a group having a tertiary carbon atom on the ring skeleton of the aliphatic cyclic group; (ii) an aliphatic cyclic group; And a group having a branched alkylene group having a tertiary carbon atom bonded thereto.
Specific examples of (i) include groups represented by the following general formulas (1-1) to (1-9).
Specific examples of (ii) include groups represented by the following general formulas (2-1) to (2-6).

［式中、Ｒ^１４はアルキル基であり、ｇは０〜８の整数である。］

[Wherein, R ¹⁴ represents an alkyl group, and g represents an integer of 0 to 8. ]

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立にアルキル基である。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents an alkyl group. ]

As the alkyl group for R ^{14 to} R ¹⁶ , a lower alkyl group is preferable, and a linear or branched alkyl group is preferable. 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. 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.

In formula (1-2), g is preferably an integer of 0 to 5, more preferably an integer of 1 to 3, and even more preferably 1 or 2.
Specific examples of the acid dissociable, dissolution inhibiting group represented by the formula (1-2) include, for example, 1-methyl-1-cyclobutyl group, 1-ethyl-1-cyclobutyl group, 1-isopropyl-1-cyclobutyl group. 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-isopropyl-1-cyclopentyl group, 1-methyl-1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 1-isopropyl- 1-cyclohexyl group, 1-methyl-1-cycloheptyl group, 1-ethyl-1-cycloheptyl group, 1-isopropyl-1-cycloheptyl group, 1-methyl-1-cyclooctyl group, 1-ethyl-1 -A cyclooctyl group etc. are mentioned.

The “acetal-type acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p1).

［式中、Ｙは直鎖状もしくは分岐鎖状のアルキル基または脂肪族環式基であり、ｎは０〜３の整数であり、Ｒ^１’およびＲ^２’はそれぞれ独立して直鎖状もしくは分岐鎖状のアルキル基または水素原子であり、ＹおよびＲ^１’が相互に結合して脂肪族環式基を形成していてもよい。］

[Wherein Y is a linear or branched alkyl group or aliphatic cyclic group, n is an integer of 0 to 3, and R ¹ ′ and R ² ′ are each independently a linear group] Or it is a branched alkyl group or a hydrogen atom, and Y and R ¹ ′ may be bonded to each other to form an aliphatic cyclic group. ]

In the above formula (p1), Y represents a linear or branched alkyl group or an aliphatic cyclic group.
When Y is linear or branched, it preferably has 1 to 15 carbon atoms, more preferably 1 to 5, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When Y is an aliphatic cyclic group, the aliphatic cyclic group is appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in large numbers in ArF resists and the like. Examples thereof include those similar to the above “aliphatic cyclic group”.
The aliphatic cyclic group for Y preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, are included. Examples include a group excluding a hydrogen atom. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.

In formula (p1), n is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
R ¹ ′ and R ² ′ are each independently a linear or branched alkyl group or a hydrogen atom.
The linear or branched alkyl group for R ¹ ′ and R ² ′ is preferably a lower alkyl group. Examples of the lower alkyl group include the same lower alkyl groups as those described above for R. A methyl group or an ethyl group is preferable, and a methyl group is most preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the group represented by the formula (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

[Wherein R ¹ ′, n and Y are the same as described above. ]

In the formula (p1), Y and R ¹ ′ may be bonded to each other to form an aliphatic cyclic group.
In this case, an aliphatic cyclic group is formed by Y, R ¹ ′, —O— (CH ₂ ) _n —, and the carbon atom to which R ² ′ is bonded. As this aliphatic cyclic group, a 4-7 membered ring is preferable and a 4-6 membered ring is more preferable. Specific examples of the aliphatic cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  As the structural unit (a1), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。］

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

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^２は酸解離性溶解抑制基を示し；Ｙ^２は２価の連結基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents a divalent linking group. ]

In general formula (a1-0-1), the lower alkyl group or halogenated lower alkyl group for R is the same as the lower alkyl group or halogenated lower alkyl group that may be bonded to the α-position of the acrylate ester. .
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. And tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred.

In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).
The divalent linking group for Y ² is preferably an alkylene group, a divalent aliphatic cyclic group, or a divalent linking group containing a hetero atom.
When Y ² is an alkylene group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and 1 to 3 carbon atoms. Most preferably it is.
When Y ² is a divalent aliphatic cyclic group, the explanation of the “aliphatic cyclic group” is the same as the aliphatic cyclic group except that a group in which two or more hydrogen atoms are removed is used. The same can be used. The aliphatic cyclic group is particularly preferably a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane or tetracyclododecane.

When Y ² is a divalent linking group containing a hetero atom, examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group or an acyl group), —S—. , —S (═O) ₂ —, —S (═O) ₂ —O—, a group represented by the formula —A—O—B—, a formula — [A—C (═O) —O] _m —. Examples thereof include a group represented by B-. Here, A and B are each independently a divalent hydrocarbon group which may have a substituent, and m is an integer of 0 to 3.
When Y ² is —NH—, the substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 5 carbon atoms. It is particularly preferred that
When Y ² is —A—O—B— or — [A—C (═O) —O] _m —B—, A and B may each independently have a substituent. It is a divalent hydrocarbon group.
m is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.

The hydrocarbon group in A may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.
The aliphatic hydrocarbon group for A may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for A include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure.
The “linear or branched aliphatic hydrocarbon group” in A preferably has 1 to 10 carbon atoms, more preferably 1 to 8, more preferably 1 to 5, and particularly preferably 1 or 2. preferable.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 _{CH 3) CH 2 -, -} C (CH 2 CH 3) 2 -CH 2 - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - , etc. An alkyl trimethylene group; —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH _{2 CH (CH 3) CH 2} CH 2 - alkyl alkylene group such as an alkyl tetramethylene group such like. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (═O), and the like.

As the “aliphatic hydrocarbon group including a ring in the structure” in A, a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), the cyclic aliphatic hydrocarbon group Includes a group bonded to the terminal of the chain aliphatic hydrocarbon group described above or interposed in the middle of the chain aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane.
As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

  As A, a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is particularly preferable. The ethylene group is most preferred.

Examples of the hydrocarbon group for B include the same divalent hydrocarbon groups as those described above for A.
B is preferably a linear or branched aliphatic hydrocarbon group, particularly preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

In the group represented by the formula — [A—C (═O) —O] _m —B—, m is an integer of 0 to 3, preferably an integer of 0 to 2, and 0 or 1 Is more preferable and 1 is most preferable.

In the present invention, the divalent linking group for Y ² is preferably a divalent group containing a hetero atom, particularly preferably a linear group having an oxygen atom as a hetero atom, such as a group containing an ester bond.
Among them, a group represented by the above-mentioned —A—O—B— or —A—C (═O) —O—B— is preferable, and in particular, — (CH ₂ ) _a —C (═O) —O— ( CH _{2) b} - group is particularly desirable.
a is an integer of 1 to 5, preferably 1 or 2, and most preferably 2.
b is an integer of 1 to 5, preferably 1 or 2, and most preferably 1.

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５の低級アルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し、Ｙ^２、Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５の低級アルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; n represents an integer of 0 to 3] Y ² and R are as defined above, and R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. ]

In the formula, X 'include the same tertiary alkyl ester-type acid dissociable, dissolution inhibiting groups as those described above for X ^{1.
R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable, dissolution inhibiting group" described above ^{(p1) ', R 2'} , n, Y The same thing is mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).
Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
Among these, the structural unit represented by the general formula (a1-1) is preferable, and specifically, (a1-1-1) to (a1-1-7) and (a1-1-36) to (a1- It is more preferable to use at least one selected from the group consisting of 1-42).
Furthermore, as the structural unit (a1), those represented by general formula (a1-1-01) shown below that include structural units of formula (a1-1-1) to formula (a1-1-5), What is represented by the following general formula (a1-1-02) including the structural units of formulas (a1-1-36) to (a1-1-42), formulas (a1-1-47) to (a1- The following general formula including the structural units represented by the following general formula (a1-1-03) including the structural units represented by 1-48) and formulas (a1-3-49) to (a1-3-52) What is represented by the formula (a1-3-01), represented by the following general formula (a1-3-02) including the structural units of the formulas (a1-3-53) to (a1-3-56) Or those represented by the following general formula (a1-3-03) including the structural units of formulas (a1-3-57) to (a1-3-58) are also preferable. Arbitrariness.

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

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group.)

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜３の整数を表す）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ¹² represents a lower alkyl group, and h represents an integer of 1 to 3)

In general formula (a1-1-01), R is the same as defined above. The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.
In general formula (a1-1-02), R is the same as defined above. The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１４は低級アルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数である。）

Wherein R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹⁴ represents a lower alkyl group, R ¹³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 10. .)

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１４は低級アルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数であり、ｎ’は０〜３の整数である。）

Wherein R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹⁴ represents a lower alkyl group, R ¹³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 10. N ′ is an integer of 0 to 3.)

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

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基であり、Ｙ^２’およびＹ^２”はそれぞれ独立して２価の連結基であり、Ｘ’は酸解離性溶解抑制基であり、ｎは０〜３の整数である。］

[Wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, Y ² ′ and Y ² ″ are each independently a divalent linking group, and X ′ is an acid dissociable, dissolution inhibiting group. And n is an integer from 0 to 3.]

In formula (a1-3-03), R is the same as R in formula (a1-3).
As the divalent linking group for Y ² ′ and Y ² ″, the same groups as those described above for Y ² in formula (a1-3) can be given.
Y ² ′ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and even more preferably a linear alkylene group. Among these, a linear alkylene group having 1 to 5 carbon atoms is preferable, and a methylene group and an ethylene group are most preferable.
Y ² ″ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and still more preferably a linear alkylene group. A linear alkylene group of 1 to 5 is preferable, and a methylene group and an ethylene group are most preferable.
The acid dissociable, dissolution inhibiting group in X ′ is the same as X ′ in the general formula (a1-3).
X ′ is preferably a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, and (i) a group having a tertiary carbon atom on the ring skeleton of the monovalent aliphatic cyclic group described above More preferably, among them, the group represented by the general formula (1-1) is preferable.
n is an integer of 0 to 3, and n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.
As the structural unit represented by the formula (a1-3-03), a structural unit represented by the following general formula (a1-3-03-1) or (a1-3-03-2) is particularly preferable. .

［式中、ＲおよびＲ^１４は前記と同じであり、ａは１〜１０の整数であり、ｂは１〜１０の整数であり、ｎは０〜３の整数である。］

[Wherein, R and R ¹⁴ are the same as defined above, a is an integer of 1 to 10, b is an integer of 1 to 10, and n is an integer of 0 to 3. ]

a is preferably an integer of 1 to 5, and most preferably 1 or 2.
b is preferably an integer of 1 to 5, and most preferably 1 or 2.
n is preferably 1 or 2.

  In the component (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, more preferably 25 to 50 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

Structural unit (a2):
The structural unit (a2) is a structural unit derived from an acrylate ester containing a lactone-containing cyclic group.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group. When it has another ring structure, it is called a polycyclic group regardless of the structure.
When the component (A1) is used for forming a resist film, the lactone cyclic group of the structural unit (a2) increases the adhesion of the resist film to the substrate or has an affinity for a developer containing water. It is effective in raising.
As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, examples of the lactone-containing monocyclic group include groups in which one hydrogen atom has been removed from γ-butyrolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) shown below.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基であり、Ｒ’は水素原子、低級アルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、前記Ｒ”は水素原子、または炭素数１〜１５の直鎖状、分岐鎖状もしくは環状のアルキル基であり、ｍは０または１の整数であり、Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子である。］

[Wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, an alkoxy group having 1 to 5 carbon atoms, or —COOR ″, wherein R ″ is A hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, m is an integer of 0 or 1, and A ″ is a carbon which may contain an oxygen atom or a sulfur atom. It is an alkylene group of formulas 1 to 5, an oxygen atom or a sulfur atom.]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (a1).
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom or fluorine atom A group in which one or more hydrogen atoms are removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with an alkyl group. Specific examples thereof include monocycloalkanes such as cyclopentane and cyclohexane, groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Can be mentioned.
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Specific examples of the alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or sulfur atom of A ″ include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, —O—CH ₂ —. _{, -CH 2 -O-CH 2 -} , - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
Below, the specific structural unit of the said general formula (a2-1)-(a2-5) is illustrated.

In the component (A1), as the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formulas (a2-1) to ( At least one selected from the group consisting of structural units represented by a2-3) is more preferred. Among them, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-2-9), (a2-2-10) ), (A2-3-1), (a2-3-2), (a2-3-9) and (a2-3-10) at least one selected from the group consisting of structural units It is preferable to use it.

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

-Structural unit (a3):
The structural unit (a3) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), a structural unit represented by (a3-2), (a3-3) ) Is preferable.

（式中、Ｒは前記に同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。）

(Wherein R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and l is an integer of 1 to 5) And s is an integer of 1 to 3.)

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 3rd position of the adamantyl group is particularly preferred.
In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on all structural units constituting the component (A1). More preferred is ˜25 mol%.

-Structural unit (a4):
The component (A1) may contain other structural units (a4) other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1) to (a3) described above, and is for ArF excimer laser and KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, a structural unit derived from acrylic acid (hereinafter referred to as a structural unit (a4 ′)) or an acrylic acid ester containing an acid non-dissociable aliphatic polycyclic group is used. Structural units (hereinafter referred to as structural units (a4 ″)) and the like.
In the structural unit (a4 ′), the “structural unit derived from acrylic acid” means a structural unit formed by cleavage of an ethylenic double bond of acrylic acid.
“Acrylic acid” includes not only acrylic acid in which a hydrogen atom is bonded to a carbon atom at the α-position, but also those in which a substituent (atom or group other than hydrogen atom) is bonded to the carbon atom in the α-position And Examples of the substituent include a lower alkyl group and a halogenated lower alkyl group. Note that the α-position (α-position carbon atom) of a structural unit derived from acrylic acid means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
In acrylic acid, examples of the lower alkyl group and halogenated lower alkyl group as the substituent at the α-position include the same as the lower alkyl group and halogenated lower alkyl group in R. In the present invention, the α-position of acrylic acid is preferably a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and preferably a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group. Are more preferable, and a hydrogen atom or a methyl group is most preferable from the viewpoint of industrial availability.
Examples of the aliphatic polycyclic group in the structural unit (a4 ″) include those similar to those exemplified in the case of the structural unit (a1). For ArF excimer laser, KrF excimer laser A number of hitherto known compounds can be used for the resin component of the resist composition such as for an ArF excimer laser, particularly tricyclodecanyl group, adamantyl group, tetracyclododeca. It is preferable that it is at least one selected from a nyl group, an isobornyl group, and a norbornyl group in terms of industrial availability, etc. These polycyclic groups are linear or branched having 1 to 5 carbon atoms. The alkyl group may be substituted as a substituent.
Specific examples of the structural unit (a4 ″) include structures having the following general formulas (a4-1) to (a4-5).

（式中、Ｒは前記と同じである。）

(In the formula, R is as defined above.)

When the structural unit (a4 ′) is contained in the component (A1), the structural unit (a4 ′) may be contained in an amount of 1 to 15 mol% with respect to the total of all the structural units constituting the component (A1). Preferably, 1 to 10 mol% is contained.
When the structural unit (a4 ″) is contained in the component (A1), the structural unit (a4 ″) is contained in an amount of 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). Preferably, 10 to 20 mol% is contained.

The component (A1) is preferably a copolymer having the structural units (a1), (a2) and (a3). Examples of such a copolymer include a copolymer composed of the structural units (a1), (a2) and (a3), and a copolymer composed of the structural units (a1), (a2), (a3) and (a4). A polymer etc. can be illustrated.
In the component (A), as the component (A1), one type may be used alone, or two or more types may be used in combination.

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

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

[(A2) component]
The component (A2) is preferably a low molecular compound having a molecular weight of 500 or more and less than 4000 and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of the component (A1). Specifically, a compound in which a part of hydrogen atoms of a hydroxyl group of a compound having a plurality of phenol skeletons is substituted with the acid dissociable, dissolution inhibiting group can be mentioned.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a soluble dissolution inhibiting group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, and bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxy. Phenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1 -[1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, bis (2,3, -trihydroxyphenyl) methane, bis (2,4- Dihydroxyphenyl) methane, 2,3,4-trihydroxyphenyl-4′-hydroxy Siphenylmethane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- ( 2 ', 4'-dihydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (3-fluoro-4-hydroxyphenyl) -2- (3'- Fluoro-4'-hydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (4 Bisphenol-type conversion such as '-hydroxyphenyl) propane and 2- (2,3,4-trihydroxyphenyl) -2- (4'-hydroxy-3', 5'-dimethylphenyl) propane Compound;
Tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane, Bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-3,5- Dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3-hydroxyphenylmethane, Bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyl Nylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4- Hydroxy-2,5-dimethylphenyl) -2,4-dihydroxyphenylmethane, bis (4-hydroxyphenyl) -3-methoxy-4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) ) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -2-hydroxyphenyl Methane and bis (5-cyclohexyl-4- Proxy-2-methylphenyl) -3,4-trisphenol compounds such dihydroxyphenyl methane;
Linear types such as 2,4-bis (3,5-dimethyl-4-hydroxybenzyl) -5-hydroxyphenol and 2,6-bis (2,5-dimethyl-4-hydroxybenzyl) -4-methylphenol Trinuclear phenolic compounds;
1,1-bis [3- (2-hydroxy-5-methylbenzyl) -4-hydroxy-5-cyclohexylphenyl] isopropane, bis [2,5-dimethyl-3- (4-hydroxy-5-methylbenzyl) ) -4-hydroxyphenyl] methane, bis [2,5-dimethyl-3- (4-hydroxybenzyl) -4-hydroxyphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl)- 4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl) -4-hydroxy-5-ethylphenyl] methane, bis [3- (3,5-diethyl- 4-hydroxybenzyl) -4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-diethyl-4-hydroxybenzyl) -4- Loxy-5-ethylphenyl] methane, bis [2-hydroxy-3- (3,5-dimethyl-4-hydroxybenzyl) -5-methylphenyl] methane, bis [2-hydroxy-3- (2-hydroxy-) 5-methylbenzyl) -5-methylphenyl] methane, bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphenyl] methane, and bis [2,5-dimethyl-3- Linear tetranuclear phenolic compounds such as (2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] methane;
2,4-bis [2-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,4-bis [4-hydroxy-3- (4-hydroxybenzyl) -5 -Methylbenzyl] -6-cyclohexylphenol and linear types such as 2,6-bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4-hydroxybenzyl] -4-methylphenol Linear polyphenol compounds such as pentanuclear phenol compounds;
1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene and 1- [1- (3-methyl-4-hydroxyphenyl) isopropyl] Polynuclear branched compounds such as -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene; 2 of formalin condensates of phenols such as phenol, m-cresol, p-cresol or xylenol ˜12 nuclei and the like. Of course, it is not limited to these.
The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.

(A) A component may be used individually by 1 type and may use 2 or more types together.
As the component (A), it is preferable to contain the component (A1).
In the resist composition of the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<(B) component>
(B) component contains the acid generator (B1) (henceforth (B1) component) which consists of a compound represented by the following general formula (b1-11).

［式中、Ｒ^７”〜Ｒ^９”はそれぞれ独立にアリール基またはアルキル基であり、Ｒ^７”〜Ｒ^９”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成していてもよく、Ｒ^７”〜Ｒ^９”のうち少なくとも１つは、置換基として下記一般式（Ｉ）で表される基を有する置換アリール基であり、Ｘ⁻はアニオンである。］

[Wherein, R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group, and any two of R ⁷ ″ to R ⁹ ″ are bonded to each other to form a ring together with the sulfur atom in the formula. It may be formed, and at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group having a group represented by the following general formula (I) as a substituent, and X ⁻ is an anion. ]

［式中、Ｗは２価の連結基を表す。］

[Wherein W represents a divalent linking group. ]

In formula (b1-11), the aryl group of R ⁷ ″ to R ⁹ ″ may be an unsubstituted aryl group having no substituent, and part or all of the hydrogen atoms are substituted with a substituent. It may be a substituted aryl group.
As an unsubstituted aryl group, a C6-C20 aryl group is mentioned, for example. The aryl group preferably has 6 to 10 carbon atoms because it can be synthesized inexpensively. As the aryl group, a phenyl group or a naphthyl group is particularly preferable.
Examples of the substituent in the substituted aryl group include a group represented by the general formula (I), an alkyl group, an alkoxy group, an ether group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.

In formula (I), preferred examples of the divalent linking group for W include a hydrocarbon group which may have a substituent, a group containing a hetero atom, and the like.
The term “having a substituent” for the hydrocarbon group means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.
The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.
The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 1 to 5, and most preferably 1 to 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 _{CH 3) CH 2 -, -} C (CH 2 CH 3) 2 -CH 2 - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - , etc. An alkyl trimethylene group; —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH _{2 CH (CH 3) CH 2} CH 2 - alkyl alkylene group such as an alkyl tetramethylene group such like. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (═O), and the like.

The aliphatic hydrocarbon group containing a ring is a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring; hereinafter, sometimes referred to as a divalent aliphatic cyclic group). And a group in which the divalent aliphatic cyclic group is bonded to the terminal of the chain aliphatic hydrocarbon group described above or is interposed in the middle of the chain aliphatic hydrocarbon group.
The divalent aliphatic cyclic group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The aliphatic cyclic group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The aliphatic cyclic group may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

The “heteroatom” in the divalent group containing a heteroatom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
As the divalent group containing a hetero atom, specifically, —O—, —C (═O) —, —C (═O) —O—, carbonate bond (—O—C (═O) —O -), -NH-, ^-NR04 ( ^R04 is an alkyl group)-, -NH-C (= O)-, = N-, or at least one of these groups and a divalent hydrocarbon group And the like. Examples of the divalent hydrocarbon group include the same hydrocarbon groups that may have a substituent as described above, and a linear or branched aliphatic hydrocarbon group is preferable.

  In the present invention, W is preferably a linear or branched alkylene group, a divalent aliphatic cyclic group or a group containing a hetero atom, more preferably a linear or branched alkylene group, A linear alkylene group is more preferred.

The alkyl group as a substituent in the substituted aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, Most preferred is an ethoxy group.
The ether group as the substituent is represented by the formula: —R ⁰¹ —R ⁰² [wherein R ⁰¹ is an alkylene group, and R ⁰² is an alkyl group. ] Is represented.
The alkylene group for R ⁰¹ may be linear, branched or cyclic, and is preferably linear or branched. Moreover, 1-10 are preferable and, as for the carbon number, 3-5 are more preferable. Specific examples of the alkylene group include groups in which one hydrogen atom has been removed from the alkyl groups listed above as unsubstituted alkyl groups.
Alkyl group R ⁰² is a linear, branched, may be any of circular, linear or branched is preferred. Moreover, 1-10 are preferable and, as for the carbon number, 1-5 are more preferable. Specifically as this alkyl group, the thing similar to the unsubstituted alkyl group quoted above is mentioned.
As the halogen atom as the substituent, a fluorine atom, a chlorine atom and the like are preferable, and a fluorine atom is most preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group mentioned as the substituent are substituted with halogen atoms. Examples of the halogen atom in the halogenated alkyl group include the same halogen atoms as those described above as the substituent. As the halogenated alkyl group, a fluorinated alkyl group is particularly preferable.

The alkyl group for R ⁷ ″ to R ⁹ ″ is not particularly limited, and examples thereof include a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.

When any two of R ⁷ ″ to R ⁹ ″ are bonded to each other to form a ring together with the sulfur atom in the formula, it is preferable to form a 3 to 10 membered ring including the sulfur atom, It is particularly preferable to form a 5- to 7-membered ring.
When any two of R ⁷ ″ to R ⁹ ″ are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one is preferably an aryl group. The aryl group is preferably a substituted aryl group having a group represented by the above general formula (I) as a substituent.

In the present invention, at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group having a group represented by the above general formula (I) as a substituent (hereinafter referred to as a substituted aryl group (I)). is there.
1-3 are preferable and 1 is the most preferable number of groups represented by general formula (I) which one substituted aryl group (I) has.
In the substituted aryl group (I), the aryl group to which the group represented by the formula (I) is bonded is preferably a phenyl group or a naphthyl group, and most preferably a phenyl group. In this case, the group represented by the formula (I) is preferably bonded to the para position of the phenyl group.
The substituted aryl group (I) may have a substituent other than the group represented by the general formula (I). Examples of the other substituent include an alkyl group, an alkoxy group, an ether group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. These are the same as those exemplified as the substituent in the substituted aryl group.
As for the number of this other substituent which one substituted aryl group (I) has, 0-2 are preferable.

Of R ⁷ ″ to R ⁹ ″, the substituted aryl group (I) may be one, two, or all three, but R ⁷ ″. Most preferably, one of ˜R ⁹ ″ is a substituted aryl group (I).
In this case, the remaining two are each an aryl group which may have a substituent other than the group represented by the formula (I), or are bonded to each other to form a sulfur atom in the formula It is preferable to form a ring together.
In the case where the remaining two are each an optionally substituted aryl group, the aryl group is preferably an unsubstituted aryl group, more preferably a phenyl group or a naphthyl group, Most preferably.
Below, the preferable specific example of the cation part of (B1) component is shown.

［式中、Ｒ^１０１〜Ｒ^１０４はそれぞれ独立にアルキル基またはアルコキシ基であり、ｎ１は１〜５の整数であり、ｎ３およびｎ４はそれぞれ独立に０〜３の整数である。］

[Wherein, R ^{101 to} R ¹⁰⁴ are each independently an alkyl group or an alkoxy group, n1 is an integer of 1 to 5, and n3 and n4 are each independently an integer of 0 to 3. ]

In formulas (b1-c-1) to (b1-c-3), the alkyl group and alkoxy group of R ^{101 to} R ¹⁰⁴ are the same as the alkyl group and alkoxy group as the substituent in the substituted aryl group, respectively. Can be mentioned.
n1 is preferably an integer of 1 to 5, more preferably an integer of 1 to 3, and most preferably 1.

In formula (b1-11), the anion of X ⁻ is not particularly limited, and one known as the anion part of the onium salt acid generator can be appropriately selected and used.
As an anion preferable as X ⁻ , for example, an anion represented by the following general formula (x-1) can be mentioned.

［式中、Ｒ^４”は、置換基を有していてもよいアルキル基、ハロゲン化アルキル基、アリール基またはアルケニル基を表す。］

[Wherein, R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group or an alkenyl group which may have a substituent.]

The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 20 carbon atoms, more preferably 4 to 15 carbon atoms, still more preferably 4 to 10 carbon atoms, and more preferably 6 to 10 carbon atoms. Most preferred.
Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.
The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.

In the above R ⁴ ″, “optionally substituted” means that part or all of the hydrogen atoms in the alkyl group, halogenated alkyl group, aryl group, or alkenyl group are substituents (other than hydrogen atoms). Other atoms or groups) may be substituted.
The number of substituents in R ⁴ ″ may be one or two or more.
Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, an oxygen atom (= O), a formula: Z-Q ^1- [where Q ¹ is a divalent linking group containing an oxygen atom, Z is a hydrocarbon group having 3 to 30 carbon atoms which may have a substituent. ] Etc. which are represented by these.
Examples of the halogen atom include the same halogen atoms as those described above for the halogenated alkyl group described for R ⁴ ″.
Examples of the alkyl group include the same alkyl groups as those described above for R ⁴ ″.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

Z-Q 1 ^- In the group represented by, Q ¹ represents a divalent linking group containing an oxygen atom.
Q ¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond; —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —O—C (═O) —, —O. —R ⁹³ —O—C (═O) —, —R ⁹² —O—C (═O) —R ⁹³ —O—C (═O) — (wherein R ^{91 to} R ⁹³ are each independently alkylene. Group.) And the like.
The alkylene group for R ^{91 to} R ⁹³ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —, Alkylethylene groups such as —CH (CH ₂ CH ₃ ) CH ₂ —; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ CH ₂ —, —CH _{2 CH (CH 3) CH 2} - alkyl trimethylene group and the like; Toramechiren group _{[-CH 2 CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; penta And methylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like.
Q ¹ is preferably a divalent linking group containing an ester bond and / or an ether bond, and among them, —O—, —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, — C (═O) —O—, —C (═O) —O—R ⁹³ —, —C (═O) —O—R ⁹³ —O—C (═O) —, —O—R ⁹³ —O —C (═O) —, —R ⁹² —O—C (═O) —R ⁹³ —O—C (═O) — are preferred.

In the group represented by ZQ ^1- , the hydrocarbon group of Z may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, and —OC (═O). R ", a hydroxyalkyl group, a cyano group, etc. are mentioned. R ″ is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
R ″ in —COOR ″ and —OC (═O) R ″ as the substituent of the aromatic hydrocarbon group is the same as R ″ in the structural unit (a2).
Examples of the hydroxyalkyl group as the substituent of the aromatic hydrocarbon group include groups in which at least one hydrogen atom of the alkyl group mentioned as the substituent is substituted with a hydroxyl group.
As the aromatic hydrocarbon group for Z, an aryl group, arylalkyl group or heteroaryl group which may have a substituent is preferable.
As the aryl group, an unsubstituted aryl group or an aryl group having a halogen atom as a substituent (halogenated aryl group) is preferable, and a phenyl group, a naphthyl group, or a fluorinated phenyl group is particularly preferable.
As the arylalkyl group, those in which the alkyl group is a methyl group are preferable, and a naphthylmethyl group or a benzyl group is preferable.
As the heteroaryl group, those containing a nitrogen atom as a hetero atom are preferred, and a group obtained by removing one hydrogen atom from pyridine is particularly preferred.

The aliphatic hydrocarbon group in Z may be a saturated aliphatic hydrocarbon group, an unsaturated aliphatic hydrocarbon group, or a combination thereof. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In Z, the aliphatic hydrocarbon group may have a part of the carbon atoms constituting the aliphatic hydrocarbon group substituted with a substituent containing a hetero atom, and the hydrogen atom constituting the aliphatic hydrocarbon group May be substituted with a substituent containing a hetero atom.
The “heteroatom” in Z is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, and a cyclic aliphatic hydrocarbon group (aliphatic cyclic group). Group) or a combination thereof.
The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

As an unsaturated hydrocarbon group, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The carbon number is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms have been removed from a monocycloalkane; a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and has one or more hydrogen atoms from the polycycloalkane. Excluded groups are preferred, and most preferred are groups in which one or more hydrogen atoms have been removed from adamantane.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include the following formulas (L1) to (L5), (S1) to (S4), and the like.

［式中、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[Wherein, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —, and R ⁹⁴ and R ⁹⁵ are each independently carbon. An alkylene group of 1 to 5 and m is an integer of 0 or 1.]

In the formula, examples of the alkylene group for Q ″, R ⁹⁴ and R ⁹⁵ include the same alkylene groups as those described above for R ^{91 to} R ⁹³ .
In these aliphatic cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
Examples of the alkoxy group and the halogen atom are the same as those exemplified as the substituent for substituting part or all of the hydrogen atoms.

In the present invention, Z preferably has a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L5), (S3) to (S4), and the like.

In the present invention, ^{R 4} ", ^{Z-Q 1} - as a substituent preferably has the case, ^{R 4."} The, ^{Z-Q 1} -Y 1 - in the Formula, ^{Q 1} and Z is the Y ¹ is an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ] Is preferable.
That is, X ⁻ is preferably an anion represented by the following general formula (x-11).

［式中、Ｑ^１は酸素原子を含む２価の連結基であり、Ｚは置換基を有していてもよい炭素数３〜３０の炭化水素基であり、Ｙ^１は置換基を有していてもよい炭素数１〜４のアルキレン基または置換基を有していてもよい炭素数１〜４のフッ素化アルキレン基である。］

[Wherein, Q ¹ is a divalent linking group containing an oxygen atom, Z is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, and Y ¹ has a substituent. Or an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ]

In formula (x-11), Z and Q ¹ are the same as defined above.
Examples of the alkylene group for Y ¹ include the same alkylene groups as those described above for Q ¹ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^1, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ¹ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

The alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl group.

  Preferable examples of the anion represented by the formula (x-11) include anions represented by the following general formula (x-11-1).

［式中、Ｚは前記と同じであり、Ｑ^２は単結合またはアルキレン基であり、ｐは１〜３の整数であり、ｍ１〜ｍ４はそれぞれ独立に０または１である。ただし、ｍ２＋ｍ３は１または２である。］

[In the formula, Z is the same as defined above, Q ² is a single bond or an alkylene group, p is an integer of 1 to 3, and m1 to m4 are each independently 0 or 1. However, m2 + m3 is 1 or 2. ]

In the formula (x-11-1), p is an integer of 1 to 3, and 1 or 2 is preferable.
Examples of the alkylene group for Q ² include the same alkylene groups as R ^{91 to} R ⁹³ in the description of Q ¹ .
m1 to m4 are each 0 or 1. However, m2 + m3 is 1 or 2.

  More specifically, as an anion represented by the formula (x-11-1), an anion represented by the following general formula (x-11-10), represented by the general formula (x-11-20) And an anion represented by the general formula (x-11-40), an anion represented by the general formula (x-11-40), and the like.

..Anions represented by general formula (x-11-10)

［式（ｘ−１１−１０）中、Ｚ、Ｑ^２、ｍ３およびｐはそれぞれ前記と同じである。］

[In the formula (x-11-10), Z, Q ² , m3 and p are the same as defined above. ]

In formula (x-11-10), as Z, an aliphatic cyclic group which may have a substituent, a linear aliphatic hydrocarbon group which may have a substituent, or a substituent An aromatic hydrocarbon group which may have a group is preferred. Among these, an aliphatic cyclic group containing a substituent containing a hetero atom in the ring structure is preferable.
Q ² is particularly preferably a single bond or a methylene group. In particular, when Z is an aliphatic cyclic group which may have a substituent, Q ² is preferably a single bond. Moreover, when X is an aromatic hydrocarbon group which may have a substituent, Q ² is preferably a methylene group.
Specific examples of suitable anions represented by general formula (x-11-10) are shown below.

［式中、Ｑ”、ｍ３およびｐはそれぞれ前記と同じであり、Ｒ^７およびＲ^７’はそれぞれ独立に置換基であり、ｗ１〜ｗ６はそれぞれ独立に０〜３の整数であり、ｖ１〜ｖ２はそれぞれ独立に０〜５の整数である。］

[Wherein Q ″, m3 and p are the same as defined above, R ⁷ and R ⁷ ′ each independently represent a substituent, w1 to w6 each independently represent an integer of 0 to 3; v2 is each independently an integer of 0 to 5.]

In the formula, examples of the substituent for R ⁷ include the same substituents as those described above as the substituent that the aliphatic hydrocarbon group may have in Z.
In the formula, examples of the substituent for R ⁷ ′ include the same substituents as those described above as the substituent that the aromatic hydrocarbon group may have in Z.
^'If the sign attached to (W1 to W6) is an integer of 2 or more, a plurality of R ⁷ or R ⁷ in the ^compound' R ⁷ or R ⁷ may be the same, respectively, be different Good.
w1 to w6 are each independently preferably 0 to 2, and most preferably 0.
v1 to v2 are each independently preferably 0 to 3, and most preferably 0.

..Anions represented by general formula (x-11-20)

［式（ｘ−１１−２０）中、Ｚおよびｐはそれぞれ前記と同じであり、Ｑ^３はアルキレン基である。］

[In formula (x-11-20), Z and p are the same as defined above, and Q ³ represents an alkylene group. ]

In formula (x-11-20), as Z, an aliphatic cyclic group which may have a substituent, a linear aliphatic hydrocarbon group which may have a substituent, or a substituent An aromatic hydrocarbon group which may have a group is preferred.
As the alkylene group for Q ^3, the same alkylene groups as those described above for R ^{91 to} R ⁹³ in the description of Q ¹ can be given.
Specific examples of preferable anions represented by general formula (x-11-20) are shown below.

［式中、ｐ、Ｒ^７およびＲ^７’はそれぞれ前記と同じであり、ｗ７〜ｗ９はそれぞれ独立に０〜３の整数であり、ｑ１は１〜１２の整数であり、ｇは１〜２０の整数である。］

[Wherein, p, R ⁷ and R ⁷ ′ are the same as defined above, w7 to w9 are each independently an integer of 0 to 3, q1 is an integer of 1 to 12, and g is 1 to 20] Is an integer. ]

^'If the sign attached to (w7~w9) is an integer of 2 or more, a plurality of R ⁷ or R ⁷ in the ^compound' R ⁷ or R ⁷ may be the same, respectively, be different Good.
w7 to w9 are each independently preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.
q1 is preferably 1 to 8, more preferably 1 to 5, and still more preferably 1 to 3.
g is preferably from 1 to 15, and more preferably from 1 to 10.
p is preferably 1 or 2, and most preferably 1.

..Anions represented by general formula (x-11-30)

［式（ｘ−１１−３０）中、ｐは前記と同じであり、ｑ２は０〜５の整数であり；Ｒ^７”はアルキル基、アルコキシ基、ハロゲン原子（ただし、フッ素原子を除く。）、ハロゲン化アルキル基、水酸基、酸素原子（＝Ｏ）、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基又はシアノ基であり；ｒ１は０〜２の整数であり、ｒ２は１〜５の整数であり、１≦ｒ１＋ｒ２≦５である。］

[In formula (x-11-30), p is as defined above, q2 is an integer of 0 to 5; R ⁷ ″ is an alkyl group, an alkoxy group, or a halogen atom (excluding a fluorine atom). , A halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group; r1 is an integer of 0 to 2, and r2 is 1. Is an integer of ˜5, and 1 ≦ r1 + r2 ≦ 5.]

In formula (x-11-30), q2 is preferably 1 to 4, more preferably 1 or 2, and most preferably 2.
R ^7, "alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, -COOR (excluding a fluorine atom.)" - OC (= O ) R ", hydroxyalkyl group, respectively, at the Z The thing similar to what was illustrated in description about the substituent which an aromatic hydrocarbon group may have is mentioned.
r1 is most preferably 0.
r2 is preferably 2 to 5, and most preferably 5.

..Anions represented by general formula (x-11-40)

［式（ｘ−１１−４０）中、ｐおよびＲ^７はそれぞれ前記と同じであり、ｑ３は１〜１２の整数であり、ｒ３は０〜３の整数である。］

[In Formula (x-11-40), p and R ⁷ are the same as defined above, q3 is an integer of 1 to 12, and r3 is an integer of 0 to 3, respectively. ]

In formula (x-11-40), R ⁷ is preferably an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), or a cyano group.
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.
If signs placed R ⁷ (r3) is an integer of 2 or more, a plurality of R ⁷ in the compounds may be each the same or different.
p is preferably 1 or 2, and most preferably 1.
q3 is preferably 1 to 5, more preferably 1 to 3, and most preferably 1.
r3 is preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.

R ⁴ ″ is also preferably one having an oxygen atom (═O) as a substituent. In this case, R ⁴ ″ is R ¹⁰ ″ — (CH ₂ ) _{n ′} — [wherein as a substituent Is a cyclic alkyl group having 4 to 20 carbon atoms having an oxygen atom (═O); n ′ is 0 or 1.] is preferred.
“Having an oxygen atom (═O) as a substituent” means that two hydrogen atoms bonded to one carbon atom constituting a cyclic alkyl group having 4 to 20 carbon atoms are replaced with an oxygen atom (═O). Means the group being
The cyclic alkyl group for R ¹⁰ ″ is not particularly limited as long as it has 4 to 20 carbon atoms, and may be either a polycyclic group or a monocyclic group. For example, monocycloalkane, bicycloalkane, tricyclo Examples include groups in which one hydrogen atom is removed from polycycloalkanes such as alkanes, tetracycloalkanes, etc. Monocyclic groups are those in which one hydrogen atom is removed from monocycloalkanes having 3 to 8 carbon atoms. Specific examples include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, etc. The polycyclic group preferably has 7 to 12 carbon atoms, specifically an adamantyl group. , Norbornyl group, isobornyl group, tricyclodecanyl group, tetracyclododecanyl group and the like.
R ¹⁰ ″ is preferably a polycyclic alkyl group having 4 to 20 carbon atoms having an oxygen atom (═O) as a substituent, and industrially constitutes an adamantyl group, norbornyl group, or tetracyclododecanyl group. A group in which two hydrogen atoms bonded to one carbon atom are substituted with an oxygen atom (═O) is preferable, and a norbornyl group having an oxygen atom (═O) as a substituent is particularly preferable.
The alkyl group for R ¹⁰ ″ may have a substituent other than the oxygen atom. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms.
In the formula: R ¹⁰ ″ — (CH ₂ ) _{n ′} —, n ′ is 0 or 1, and preferably 1.
When R ⁴ ″ is a group represented by R ¹⁰ ″ — (CH ₂ ) _{n ′} —, X ⁻ represents a camphorsulfonate ion (an ion in which one of camphor's hydrogen atoms is replaced by —SO ₃ ^— ). In particular, an ion represented by the following chemical formula (x-12-1) (a sulfonate ion (—SO ₃ ⁻ ) bonded to a carbon atom of a methyl group bonded to the 1-position of the norbornane ring) ) Is preferable.

In addition to the above, examples of the anion that can be used as X ⁻ include anions represented by the following general formula (b-3) or (b-4).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、置換基を有していてもよいアルキル基またはハロゲン化アルキル基を表す。Ｚ”に結合した−ＳＯ_２−は、−Ｃ（＝Ｏ）−に置換されていてもよい。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently have a substituent. Represents a good alkyl group or a halogenated alkyl group. —SO ₂ — bonded to Z ″ may be substituted with —C (═O) —. ]

X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Most preferably, it has 3 carbon atoms.
The number of carbon atoms of the alkylene group of X ″ is preferably as small as possible because, for example, the solubility in a resist solvent is good within the range of the carbon number.
In the alkylene group of X ″, the larger the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid and the better the transparency to high energy light of 200 nm or less and electron beam. The proportion of fluorine atoms in the group or alkyl group, that is, the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably, a hydrogen atom in which all hydrogen atoms are substituted with fluorine atoms. A fluoroalkylene group or a perfluoroalkyl group;

The alkyl group in Y ″ and Z ″ may be linear, branched or cyclic, and examples thereof include the same alkyl groups as those described above for R ⁴ ″.
The halogenated alkyl group in Y ″ and Z ″ is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms, and examples thereof include the same as the halogenated alkyl group in R ⁴ ″. .
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.
As the halogenated alkyl group, a fluorinated alkyl group is particularly preferred.

The alkyl group or halogenated alkyl group in Y ″ and Z ″ may have a substituent.
The phrase “may be substituted” in the alkyl group in Y ″ and Z ″ means that part or all of the hydrogen atoms in the alkyl group may be substituted with a substituent. The halogenated alkyl group in Y ″ and Z ″ “may have a substituent” means that some or all of the halogen atoms and hydrogen atoms in the halogenated alkyl group are substituted with substituents. Also means good. The number of substituents in Y ″ and Z ″ may be one or two or more.
The substituent which the alkyl group or halogenated alkyl group in Y ″ and Z ″ may have may be any atom or group other than a carbon atom, a hydrogen atom and a halogen atom. Group, formula: Z ⁵ -Q ^5- [wherein Q ⁵ is a divalent linking group containing an oxygen atom, and Z ⁵ is a hydrocarbon group having 3 to 30 carbon atoms which may have a substituent. It is. ] Etc. which are represented by these.
Among these substituents, examples of the hetero atom and the alkyl group include the same hetero atoms and alkyl groups as those described above as the substituent for R ⁴ ″.

In the group represented by Z ⁵ -Q ^5- , Q ² is a divalent linking group containing an oxygen atom.
Examples of Q ⁵ include the same as Q ¹ in the group represented by ZQ ^1- .
Q ⁵ is preferably a divalent linking group containing an ester bond and / or an ether bond, and in particular, —O—, —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, — C (═O) —O—, —C (═O) —O—R ⁹³ — or —C (═O) —O—R ⁹³ —O—C (═O) — are preferred.
In the group represented by Z ⁵ -Q ^5- , Z ⁵ is a hydrocarbon group having 3 to 30 carbon atoms which may have a substituent.
Examples of Z ⁵ include the same as Z in the group represented by ZQ ¹ —.
Z ⁵ is preferably an aliphatic hydrocarbon group, more preferably a linear or cyclic aliphatic hydrocarbon group, and still more preferably a cyclic aliphatic hydrocarbon group.

In formula (b-4), —SO ₂ — bonded to Z ″ may be substituted with —C (═O) —. That is, the anion moiety represented by formula (b-4) is: It may be represented by the following general formula (b-4 ′).

［式中、Ｙ”、Ｚ”は、上記と同様である。］

[Wherein Y ″ and Z ″ are the same as above. ]

In the present invention, in formula (b-4) and formula (b-4 ′), at least one of Y ″ and Z ″ is a fluorinated alkyl group which may have a substituent. preferable.
In particular, in formula (b-4), it is preferable that one of Y ″ and Z ″ is a perfluoroalkyl group, and the other is an optionally substituted alkyl group or fluorinated alkyl group. . In formula (b-4 ′), one of Y ″ and Z ″ is preferably a perfluoroalkyl group, and the other is preferably an alkyl group which may have a substituent. It is preferably a perfluoroalkyl group, and Z ″ is an alkyl group which may have a substituent.
Examples of the anion represented by the formula (b-4) or the formula (b-4 ′) in such a case include anions represented by the following formulas (b4-1) to (b4-8). .

［式中、Ｒ^７は置換基であり、ｓ１〜ｓ４はそれぞれ独立に０〜３の整数であり、ｚ１〜ｚ６はそれぞれ独立に０〜３の整数であり、ｐは０〜４の整数であり、ｍ_１１〜ｍ_１３は０又は１であり、ｇは１〜４の整数であり、ｔは１〜２０の整数である。］

[Wherein R ⁷ is a substituent, s1 to s4 are each independently an integer of 0 to 3, z1 to z6 are each independently an integer of 0 to 3, and p is an integer of 0 to 4. M _{11 to} m ₁₃ are 0 or 1, g is an integer of 1 to 4, and t is an integer of 1 to 20. ]

In the above formula, as the substituent for R ^7, the substituent that the aliphatic hydrocarbon group may have in the Z of the group represented by ZQ ¹ — may have. The thing similar to what was mentioned as is mentioned.
If signs placed R ⁷ (s1 to s4) is an integer of 2 or more, a plurality of the R ⁷ groups may be the same, respectively, it may be different.
s1 to s4 are preferably 0 or 1, and most preferably 0.
z1 to z6 are preferably 0 or 1.
p ″ is preferably 0 to 2.
m ₁₂ is preferably 0.
h is preferably 1 or 2, and most preferably 1.
t is more preferably 1 to 15, and further preferably 3 to 12.
In the present invention, anions represented by formulas (b4-1) to (b4-4) are particularly preferable.

In addition to the above, an anion that can be used as X ⁻ includes a methide anion. Examples of the metide anion include anions represented by the following general formula (b-c1).

［式中、Ｒ^８”は、少なくとも１の水素原子がフッ素置換されている炭素数１〜１０のアルキル基であり；Ｒ^９”は、置換基を有していてもよい炭化水素基、または−ＳＯ_２−Ｒ^８”である。］

[Wherein R ⁸ ″ is an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with fluorine; R ⁹ ″ is a hydrocarbon group which may have a substituent, or —SO ₂ —R ⁸ ″.]

In formula (b-c1), R ⁸ ″ is an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with fluorine. Examples of the alkyl group include linear, branched, and cyclic. In the present invention, R ⁸ ″ is preferably a linear or branched alkyl group, and more preferably a linear alkyl group.
In the formula (b-c1), when R ⁹ ″ is a hydrocarbon group which may have a substituent (the “hydrocarbon group which may have a substituent” means the hydrocarbon group And a part or all of the hydrogen atoms constituting R may be substituted with a substituent.), The hydrocarbon group of R ⁹ ″ may be an aliphatic hydrocarbon group, A hydrogen group may be used, and specific examples include the same as Z in the above formula: ZQ ^1- .
R ⁹ ″ is preferably an aryl group having a halogen atom as a substituent (halogenated aryl group) or —SO ₂ —R ⁸ ″. Examples of the aryl group in the halogenated aryl group include groups in which some or all of the hydrogen atoms of an aryl group having 6 to 10 carbon atoms such as a phenyl group and a naphthyl group are substituted with a halogen atom. The halogen atom in the halogenated aryl group is preferably a fluorine atom.

X ⁻ is preferably an anion represented by the general formula (x-1) among the above. Among them, an anion in which R ⁴ ″ in the formula (x-1) is a fluorinated alkyl group which may have a substituent, that is, a fluorinated alkyl sulfonate ion which may have a substituent is preferable. .
As the anion represented by the formula (x-1), an anion is preferably represented by the general formula (x-11), in particular, ^{Y 1} in the formula (x-11) has a substituent What is a C1-C4 fluorinated alkylene group which may be sufficient is preferable.
Further, X ^- as an anion and represented by general formula (b-3) or (b-4), anions is also preferably represented by the formula (x-12-1).

As the component (B1), one type may be used alone, or two or more types may be used in combination.
In the component (B), the proportion of the component (B1) is preferably 1 to 100% by mass, more preferably 5 to 70% by mass, and still more preferably 10 to 50% by mass.

The resist composition of the present invention may contain, as the component (B), an acid generator component (hereinafter referred to as the component (B2)) that does not correspond to the component (B1).
The component (B2) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and poly (bissulfonyl) diazomethanes. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表し；Ｒ^４”は前記と同じである。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; among R ¹ ″ to R ³ ″ in formula (b-1), Any two of them may be bonded to each other to form a ring together with the sulfur atom in the formula; at least one of R ¹ ″ to R ³ ″ represents an aryl group, and of R ⁵ ″ to R ⁶ ″ At least one represents an aryl group; R ⁴ ″ is as defined above.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. In addition, any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Further, at least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.
The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may or may not be substituted with a group, ether group, halogen atom, halogenated alkyl group, hydroxyl group or the like. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
As the alkyl group, ether group, halogen atom and halogenated alkyl group in which the hydrogen atom of the aryl group may be substituted, the aryl group in R ⁷ ″ to R ⁹ ″ may have a substituent. Examples are the same as the alkyl group, ether group, halogen atom, and halogenated alkyl group mentioned as the group.
The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
Among these, R ¹ ″ to R ³ ″ are most preferably a phenyl group or a naphthyl group, respectively.

When any two of R ¹ ″ to R ³ ″ in the formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, a 3 to 10 membered ring including the sulfur atom is formed. It is preferable that a 5- to 7-membered ring is formed.
When any two of R ¹ ″ to R ³ ″ in formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one may be an aryl group preferable. Examples of the aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"As ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
In addition, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

  In addition, in the general formula (b-1) or (b-2), an onium salt-based acid generator in which the anion moiety is replaced with the anion moiety represented by the general formula (b-3) or (b-4). Can also be used (the cation moiety is the same as (b-1) or (b-2)).

  Moreover, the sulfonium salt which has a cation part represented by the following general formula (b-5) or (b-6) can also be used as an onium salt type | system | group acid generator.

［式中、Ｒ^４１〜Ｒ^４６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[Wherein R ^{41 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{1 to} n ₅ are each independently an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

In R ^{41 to} R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, an isopropyl group, n A butyl group or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the codes n _{1 to} n ₆ attached to R ^{41 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

The anion part of the sulfonium salt having a cation part represented by the formula (b-5) or (b-6) is not particularly limited, and is the same as the anion part of the onium salt acid generators proposed so far. It may be a thing. Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ^{4 ″} SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). An anion moiety represented by the general formula (b-3) or (b-4), etc. Among them, a fluorinated alkyl sulfonate ion is preferable, and a fluorinated alkyl sulfonic acid having 1 to 4 carbon atoms. Ion is more preferable, and linear perfluoroalkylsulfonic acid ions having 1 to 4 carbon atoms are particularly preferable, and specific examples thereof include trifluoromethylsulfonic acid ions, heptafluoro-n-propylsulfonic acid ions, and nonafluoro-n. -Butyl sulfonate ion etc. are mentioned.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.

As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.

As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), WO2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

As the component (B2), any one of these acid generators may be used alone, or two or more kinds may be used in combination.
As component (B2), among the above, R ⁴ ″ may be an anion which is a fluorinated alkyl group which may have a substituent, that is, a fluorinated alkyl sulfonate ion which may have a substituent. Preferred is an onium salt acid generator.
In particular, it is preferable that Y ¹ in the general formula (x-11) is a fluorinated alkylene group having 1 to 4 carbon atoms which may have a substituent.

  The content of the component (B) in the resist composition of the present invention is preferably 0.5 to 60 parts by mass, more preferably 1 to 40 parts by mass, further preferably 3 with respect to 100 parts by mass of the component (A). -30 mass parts. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<Optional component>
The resist composition of the present invention contains a nitrogen-containing organic compound (D) (hereinafter referred to as (D) component) as an optional component for the purpose of improving the resist pattern shape, the stability over time, etc. May be.
As the component (D), a wide variety of components have already been proposed, and any known one may be used. Among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are used. preferable. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 20 carbon atoms.
Examples of the aliphatic amine include an amine (alkylamine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 20 or less carbon atoms. .
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, etc .; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amine, tri -n- octanol amine, stearyl diethanolamine, alkyl alcohol amines such as lauryl diethanolamine. Among these, trialkylamine and / or alkyl alcohol amine are preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
Examples of the aromatic amine include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, and tribenzylamine.
Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2 -(1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxy Ethoxy) ethoxy} ethylamine and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

The resist composition of the present invention includes, as optional components, organic carboxylic acids, and phosphorus oxo acids and derivatives thereof for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, stability with time, and the like. You may contain the at least 1 sort (s) of compound (E) (henceforth (E) component) selected.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids and derivatives thereof include phosphoric acid, phosphonic acid, phosphinic acid and the like, and among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
As the component (E), an organic carboxylic acid is preferable, and salicylic acid is particularly preferable.
(E) A component is normally used in the ratio of 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

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

<Organic solvent>
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution, and any one of conventionally known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent, dimethyl sulfoxide (DMSO), etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA or PGME, and the polar solvent is preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA or PGME and a polar solvent, and is preferably 1: 9 to 9: 1, more preferably 2: 8 to The range is 8: 2.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
Furthermore, a mixed solvent of PGME and dimethyl sulfoxide is also preferable. In this case, the mixing ratio of the former and the latter is preferably 9: 1 to 1: 9, more preferably 8: 2 to 2: 8, and most preferably 7: 3 to 5: 5. It is.
The amount of the component (S) used is not particularly limited, but is a concentration that can be applied to the support and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 -20% by mass, preferably 3-15% by mass.

  The dissolution of the material in the component (S) can be carried out, for example, by simply mixing and stirring each of the above components by a usual method, and if necessary, a disperser such as a dissolver, a homogenizer, or a three roll mill You may use and disperse and mix. Moreover, after mixing, you may further filter using a mesh, a membrane filter, etc.

The resist composition of the present invention is a novel one that has not been conventionally known.
Further, according to the resist composition of the present invention, since the solubility of the component (B1) in the alkaline developer is high, a resist pattern in which pattern trailing is suppressed can be formed. In particular, tailing on the inorganic substrate can be suppressed.
Moreover, according to the resist composition of this invention, a defect can be reduced.
In particular, when the anion portion of the component (B1) is an anion represented by the general formula (x-11), the effect of improving lithography properties is excellent. The reason why such an effect is obtained is that the anion moiety has a structure in which a functional group of “ZQ ¹ —” is introduced into the skeleton of Y ¹ —SO ₃ ^— , whereby Y ¹ is fluorine-substituted. Despite the relatively small number of carbon atoms of the alkylene group, which may be 1-4, excessive diffusion of acid after exposure is suppressed compared to the anion portion of conventional acid generators such as nonafluorobutanesulfonate. This is probably because of this.
Further, such an anion moiety is such that Y ¹ is an alkyl chain of an alkylene group having 1 to 4 carbon atoms which may be substituted with fluorine, and a perfluoroalkyl chain having 6 to 10 carbon atoms is hardly decomposable. In comparison, it is safer in terms of handling considering bioaccumulation.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention includes a step of forming a resist film on a support using the resist composition of the present invention, a step of exposing the resist film, and developing the resist film to form a resist pattern. Forming.
The resist pattern forming method of the present invention can be performed, for example, as follows.
First, the resist composition of the present invention is coated on a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 90, under a temperature condition of 80 to 150 ° C. For example, ArF excimer laser light is selectively exposed through a desired mask pattern using an ArF exposure apparatus or the like, and then subjected to PEB (post-exposure heating) at a temperature of 80 to 150 ° C. for 40 to 120. Second, preferably 60-90 seconds. Subsequently, this is developed using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH), preferably rinsed with pure water and dried. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern faithful to the mask pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC).
The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition is effective for KrF excimer laser, ArF excimer laser, EB or EUV, particularly ArF excimer laser.

The exposure of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure.
In immersion exposure, as described above, the portion between the lens, which has been conventionally filled with an inert gas such as air or nitrogen, and the resist film on the wafer is refracted larger than the refractive index of air. The exposure is performed in a state filled with a solvent having a high rate (immersion medium).
More specifically, the immersion exposure is a solvent (immersion medium) having a refractive index larger than the refractive index of air between the resist film obtained as described above and the lowermost lens of the exposure apparatus. And in that state, exposure can be performed through a desired mask pattern (immersion exposure).
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film exposed by the immersion exposure is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).

≪Compound≫
The compound of the 3rd aspect of this invention is a compound (henceforth a compound (b1-11)) represented by the said general formula (b1-11).
The compound (b1-11) is the same as the component (B1) in the resist composition according to the first aspect of the present invention.
Compound (b1-11) is a novel compound which has not been conventionally known. In addition, the compound (b1-11) is useful as an acid generator for resist compositions.

Compound (b1-11) can be produced by a conventional method.
Specifically, for example, when R ⁷ ″ is an aryl group having one group represented by the formula (I), the compound (hereinafter referred to as compound (b1-11-1)) is It can be manufactured as follows.
First, in a solution of an organic acid H ⁺ B ⁻ (B ⁻ represents an anion part of an organic acid such as a methanesulfonate ion), a compound represented by the formula (b1-01) and the formula ( b1-02) is added and reacted, and then pure water and an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.) are added to recover the organic layer. From this organic layer, the formula (b1-03) is recovered. ) Is recovered.
Next, the compound represented by the general formula (b1-03) is added to an organic solvent (for example, acetone, dichloromethane, tetrahydrofuran, etc.) and cooled, and then the compound represented by the following general formula (b1-0) After adding, reacting, and separating and washing with water, a compound represented by the following general formula (b1-05) is obtained from the organic layer.
Then, pure water was added to the compound represented by the formula (B1-05), the -OR ^x dissociated (deprotection) by hydrolysis, represented by the following general formula (B1-06) A compound is obtained. Hydrolysis can be carried out, for example, by adding an acid (hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, etc.) or a base and heating.
Next, the compound represented by the formula (b1-06) is dissolved in a mixed solvent of an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.) and water, and the desired anion X ⁻ alkali metal salt L ⁺ X ⁻ ( L ⁺ represents, for example, an alkali metal cation such as lithium ion or potassium ion), and the mixture is reacted, followed by liquid separation and washing with water, and then the compound (b1-11-1) is recovered from the organic layer.

［式中、Ｒ^８”〜Ｒ^９”、Ｘ⁻、Ｗはそれぞれ前記と同じであり、Ａｒはアリーレン基であり、Ｂ⁻は有機酸のアニオン部であり、Ｌ^＋はアルカリ金属カチオンであり、Ｘ_ｈはハロゲン原子であり、Ｒ^ｘは保護基である。］

[Wherein R ⁸ ″ to R ⁹ ″, X ⁻ and W are the same as defined above, Ar is an arylene group, B ⁻ is an anion portion of an organic acid, and L ⁺ is an alkali metal cation. , X _h is a halogen atom, and R ^x is a protecting group. ]

Examples of the arylene group for Ar include a group in which one hydrogen atom has been removed from the aryl group which may have a substituent described in the above R ⁷ ″ to R ⁹ ″.
Examples of the halogen atom for X _h, a bromine atom or a chlorine atom is preferable.
The protecting group for R ^x is not particularly limited as long as it is an organic group that can be deprotected by hydrolysis. Dissolution inhibiting groups can be used.
The production method of the compound (b1-11-1) is not limited to the above, for example, in the above manufacturing method, in _X h -W-COOH [wherein instead of the compound represented by formula (b1-04), And W are as defined above. ], The compound represented by the formula (b1-06) can also be obtained by directly introducing -W-COOH into the hydroxyl group of the compound represented by the formula (b1-03).
The structure of the obtained compound is as follows: ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method, mass spectrometry (MS) method, element It can be confirmed by a general organic analysis method such as analysis method or X-ray crystal diffraction method.

≪Acid generator≫
The acid generator according to the fourth aspect of the present invention is composed of the compound according to the third aspect of the present invention.
The acid generator is used in combination with a resist composition.
Although it does not specifically limit as a resist composition with which this acid generator is mix | blended, The base material component from which the solubility with respect to an alkali developing solution changes with the effect | action of an acid, and the acid generator component which generate | occur | produces an acid by exposure are contained. A chemically amplified resist composition is preferred.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
[Synthesis Example 1]
343.6 g of 30% aqueous sodium hydroxide solution was added dropwise to 150 g of methyl fluorosulfonyl (difluoro) acetate and 375 g of pure water while maintaining the temperature at 10 ° C. or lower in an ice bath. After dropping, the mixture was refluxed at 100 ° C. for 3 hours, cooled and neutralized with concentrated hydrochloric acid. The obtained solution was added dropwise to 8888 g of acetone, and the precipitate was filtered and dried to obtain 184.5 g of compound (1-1) (purity: 88.9%, yield: 95.5%) as a white solid. Obtained.

  56.2 g of compound (1-1) and 562.2 g of acetonitrile were charged, 77.4 g of p-toluenesulfonic acid monohydrate was added, and the mixture was refluxed at 110 ° C. for 3 hours. Then, it filtered and the filtrate was concentrated and dried. To the obtained solid, 900 g of t-butyl methyl ether was added and stirred. Thereafter, the mixture was filtered and the filtrate was dried to obtain 22.2 g of compound (1-2) (purity: 91.0%, yield: 44.9%) as a white solid.

  Charge 4.34 g (purity: 94.1%) of the compound (1-2), 3.14 g of 2-benzyloxyethanol, and 43.4 g of toluene, and add 0.47 g of p-toluenesulfonic acid monohydrate. And refluxed at 105 ° C. for 20 hours. The reaction solution was filtered, and 20 g of hexane was added to the filtrate and stirred. Filtration was performed again, and the residue was dried to obtain 1.41 g (yield: 43.1%) of compound (1-3).

  To 1.00 g of compound (1-3) and 3.00 g of acetonitrile, 0.82 g of 1-adamantanecarbonyl chloride and 0.397 g of triethylamine were added dropwise under ice cooling. After completion of dropping, the mixture was stirred at room temperature for 20 hours and filtered. The filtrate was concentrated to dryness, dissolved in 30 g of dichloromethane and washed with water three times. The organic layer was concentrated and dried to obtain 0.82 g (yield: 41%) of compound (1-4).

The obtained compound (1-4) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 8.81 (s, 1H, H ^c ), 4.37-4.44 (t, 2H, H ^d ), 4.17-4 .26 (t, 2H, H ^e ), 3.03-3.15 (q, 6H, H ^b ), 1.61-1.98 (m, 15H, Adamantane), 1.10-1.24 ( t, 9H, H ^a ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.6.
From the results shown above, it was confirmed that the compound (1-4) had a structure shown below.

[Synthesis Example 2]
Compound (2-1) (16.0 g) (manufactured by Wako Pure Chemical Industries, Ltd.) and pure water (131.7 g) were added to a three-necked flask, and hydrochloric acid (5.20 g) was added dropwise thereto. Heating under reflux was performed for 12 hours. The aqueous layer was washed with t-butyl methyl ether (TBME) (131.7 g) to obtain compound (2-2) (10.0 g).
The compound (2-2) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 2.30 (d, 6H, Ha), 4.53 (s, 2H, Hb), 7.59 (s, 2H, Ar), 7.71-7.89 (m, 10H, Ar).
From the results shown above, it was confirmed that the compound (2-2) had a structure shown below.

[Synthesis Example 3]
Pure water (60.5 g) and dichloromethane (131.1 g) were added to compound (2-2) (5.01 g), and compound (1-4) (4.53 g) was added thereto, and the mixture was stirred at room temperature for 3 hours. Stir. Thereafter, the dichloromethane layer was taken out by liquid separation, washed twice with dilute hydrochloric acid (65.5 g), and then washed four times with pure water (65.5 g). The dichloromethane layer was concentrated and dried to obtain Compound (3-1) (6.05 g) as a white solid.
The compound (3-1) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.5-1.93 (m, 15H, adamantane), 2.29 (d, 6H, Ha), 4.20 (t, 2H) , Hc), 4.41 (t, 2H, Hd), 4.51 (s, 2H, Hb), 7.59 (s, 2H, Ar), 7.71-7.89 (m, 10H, Ar) ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.9.
From the results shown above, it was confirmed that the compound (3-1) had a structure shown below.

[Synthesis Example 4]
Pure water (45.3 g) and dichloromethane (90.5 g) were added to compound (2-2) (20 g), potassium nonafluorobutanesulfonate (16.8 g) was added thereto, and the mixture was stirred at room temperature for 15 hours. . Thereafter, the dichloromethane layer was taken out by liquid separation, washed twice with dilute hydrochloric acid (45.3 g), and then washed four times with pure water (45.3 g). The dichloromethane layer was concentrated and dried to obtain Compound (3-2) (26.4 g) as a white solid.

The compound (3-2) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 2.30 (d, 6H, Ha), 4.39 (s, 2H, Hb), 7.32 (s, 2H, Ar), 7.70-7.87 (m, 10H, Ar).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 123.7, −119.3, −112.4, −78.6.

[Synthesis Example 5]
Compound (2-2) (2 g) was added to dichloromethane (20 g) and pure water (20 g) and stirred. Thereto, the following compounds ^{(M +} X -) was added (2.20 g), and stirred at room temperature for 1 hour. Thereafter, the dichloromethane layer was taken out by liquid separation and washed four times with pure water (20 g). The dichloromethane layer was concentrated and dried to obtain the target compound (5-1) (2.4 g).
The compound (5-1) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.70-7.87 (m, 10H, Ar), 7.32 (s, 2H, Ar), 4.4-4.5 _{(t, 4H, CH 2)} , 4.39 (s, 2H, -O-CH 2 -CO -), 2.30 (d, 6H, Ar-CH 3).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.7, −154.0, −160.0, −161.5.
From the results shown above, it was confirmed that the compound (5-1) had the structure shown above.

[Synthesis Examples 6 to 25 (Synthesis of Compounds (5-2) to (5-20))]
The same operation as in Synthesis Example 5 was conducted except that the compound (M ⁺ X ⁻ ) was synthesized by changing it to those shown in the following Tables 1 to 5 (equal molar amount). This obtained the product (compound (5-2)-(5-20)) which consists of an anion and a cation shown in Tables 1-5. Each compound was analyzed by NMR, and the results are shown in Tables 1 to 5. In Tables 1 to 5, “↑” indicates that the cations of the compounds (5-3) to (5-20) are the same as the cation of the compound (5-2).

[Examples 1-2, Comparative Examples 1-2]
Each component shown in Table 6 below was mixed and dissolved to prepare a positive resist composition.

In Table 6, each abbreviation indicates the following, and the numerical value in [] is the blending amount (part by mass).
(A) -1: the following polymer compound (1) (mass average molecular weight 10,000, dispersity 2.0, 1 / m / n / o = 36.5 / 36.1 / 18.3 / 9.1 / ( Molar ratio))
(B) -1: Compound (3-2).
(B) -2: Compound (3-1).
(B) -3: 4-Methylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate.
(B) -4: Tri (4-tert-butylphenyl) sulfonium nonafluoro-n-butanesulfonate.
(D) -1: Tri-n-pentylamine (S) -1: Mixed solvent of PGMEA / PGME = 6/4 (mass ratio).

[Resist pattern formation]
An inorganic antireflection film-forming composition “HM40” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 250 ° C. for 90 seconds. Then, an inorganic antireflection film having a film thickness of 40 nm was formed by drying. Then, each of the resist compositions is applied onto the antireflection film using a spinner, prebaked (PAB) on a hot plate at 110 ° C. for 60 seconds, and dried to obtain a film thickness. A 180 nm resist film was formed.
Next, an ArF excimer laser (193 nm) is applied to the resist film by using an ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination) as a mask pattern. Selectively irradiated. Then, post-exposure heating (PEB) treatment is performed at 110 ° C. for 60 seconds, and further development is performed at 23 ° C. with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 30 seconds, and then 30 Water rinsing was performed using pure water for 2 seconds, and then shaken off and dried.
As a result, in each of the examples, a line-and-space resist pattern (hereinafter referred to as an L / S pattern) having a line width of 120 nm and a pitch of 240 nm was formed on the resist film.
The optimum exposure dose Eop (mJ / cm ² ) for forming the L / S pattern having the line width of 120 nm and the pitch of 240 nm was determined. The results are shown in Table 7.
Further, the cross-sectional shape of the LS pattern having a line width of 120 nm and a pitch of 240 nm formed by the Eop was observed using a length measurement SEM (scanning electron microscope, trade name: S-9220, manufactured by Hitachi, Ltd.) The rectangularity was evaluated according to the following criteria. The results are shown in Table 7.
(Criteria)
◯: The resist pattern had no rectangular pattern and high rectangularity.
X: Pattern skirting was observed.

  From the above results, it was confirmed that the pattern tailing on the inorganic substrate can be improved by using an acid generator having a specific carboxylic acid in the cation portion.

[Measurement of dissolution rate (R _max )]
In the resist compositions of Examples 1 and 2 and Comparative Examples 1 and 2, the (A) component was replaced with the following polymer compound (A) -2 which is a resin soluble in an alkaline developer. These were used as resist compositions of Examples 1 ′ to 2 ′ and Comparative Examples 1 ′ to 2 ′, respectively.
These resist compositions are uniformly applied onto an 8-inch silicon substrate using a spinner, and prebaked (PAB) at 110 ° C. for 60 seconds on a hot plate to form a resist having a thickness of 160 nm. A film was formed.
The resist film is immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 23 ° C. for 10 seconds, and the maximum value (R _max , dissolution rate (film reduction amount / immersion time)) (Unit: nm / s) was determined by RDA-808RB (trade name, manufactured by RISOTEC JAPAN). The results are shown in Table 8.

［式中、ｍ：ｎ＝５０：５０（モル比）であり、Ｍｗ５２００、Ｍｗ／Ｍｎ１．７７の共重合体。］

[Wherein, m: n = 50: 50 (molar ratio), Mw5200, Mw / Mn1.77 copolymer. ]

  As described above, the resist films formed using the resist compositions of Examples 1 'to 2' were highly soluble in an alkaline developer. From this result, the acid generators (B) -1 and (B) -2 have higher solubility in an alkali developer than (B) -3 and (B) -4, and the acid generator is blended. It was shown that it is difficult to inhibit the solubility of the resist composition in the alkaline developer.

Claims (18)

A resist composition containing a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure,
The resist composition, wherein the acid generator component (B) includes an acid generator (B1) composed of a compound represented by the following general formula (b1-11).

[Wherein, R ^{101 to} R ¹⁰⁴ are each independently an alkyl group or an alkoxy group, n1 is an integer of 1 to 5, and n3 and n4 are each independently an integer of 0 to 3. X ⁻ is an anion. ] The resist composition according to claim 1, wherein X ⁻ in the general formula (b1-11) is an anion represented by the following general formula (x-1).

[Wherein, R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group or an alkenyl group which may have a substituent.] The resist composition according to claim 2, wherein X ⁻ in the general formula (b1-11) is an anion represented by the following general formula (x-11).

[Wherein, Q ¹ is a divalent linking group containing an oxygen atom, Z is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, and Y ¹ has a substituent. Or an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ] 2. The resist composition according to claim 1, wherein X ⁻ in the general formula (b1-11) is an anion represented by the following general formula (b-3) or (b-4).

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently have a substituent. Represents a good alkyl group or a halogenated alkyl group. —SO ₂ — bonded to Z ″ may be substituted with —C (═O) —. ] 2. The resist composition according to claim 1, wherein X ⁻ in the general formula (b1-11) is an anion represented by the following general formula (b-c1).

[Wherein R ⁸ ″ is an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with fluorine; R ⁹ ″ is a hydrocarbon group which may have a substituent, or —SO ₂ —R ⁸ ″.]   It is a positive resist composition, The resist composition as described in any one of Claims 1-5.   The resist composition according to claim 6, wherein the substrate component (A) is a resin (A1) whose solubility in an alkaline developer is increased by the action of an acid.   The resist composition according to claim 7, wherein the resin (A1) has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.   The resist composition according to claim 8, wherein the resin (A1) further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.   The resist composition according to claim 8 or 9, wherein the resin (A1) further has a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.   Furthermore, the resist composition as described in any one of Claims 1-10 containing a nitrogen-containing organic compound component (D).   A step of forming a resist film on the support using the resist composition according to any one of claims 1 to 11, a step of exposing the resist film, and an alkali developing of the resist film to form a resist pattern A resist pattern forming method including a step of forming a film. The compound represented by the following general formula (b1-11).

[Wherein, R ^{101 to} R ¹⁰⁴ are each independently an alkyl group or an alkoxy group, n1 is an integer of 1 to 5, and n3 and n4 are each independently an integer of 0 to 3. X ⁻ is an anion. ] The compound according to claim 13, wherein X ⁻ in the general formula (b1-11) is an anion represented by the following general formula (x-1).

[Wherein, R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group or an alkenyl group which may have a substituent.] The compound according to claim 14, wherein X ⁻ in the general formula (b1-11) is an anion represented by the following general formula (x-11).

[Wherein, Q ¹ is a divalent linking group containing an oxygen atom, Z is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, and Y ¹ has a substituent. Or an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ] The compound according to claim 13, wherein X ⁻ in the general formula (b1-11) is an anion represented by the following general formula (b-3) or (b-4).

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently have a substituent. Represents a good alkyl group or a halogenated alkyl group. —SO ₂ — bonded to Z ″ may be substituted with —C (═O) —. ] The compound according to claim 13, wherein X ⁻ in the general formula (b1-11) is an anion represented by the following general formula (b-c1).

[Wherein R ⁸ ″ is an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with fluorine; R ⁹ ″ is a hydrocarbon group which may have a substituent, or —SO ₂ —R ⁸ ″.]   The acid generator which consists of a compound as described in any one of Claims 13-17.