JP5638106B2 - Novel compounds and acid generators - Google Patents

Description

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

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. Currently, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has been started. Further, studies have been made on 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 a base resin for chemically amplified resist, polyhydroxystyrene (PHS) having high transparency with respect 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 the main chain because it is excellent in 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. Resins having structural units derived from 2-adamantyl (meth) acrylate or the like are mainly used (see, for example, 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.

On the other hand, various acid generators used in chemically amplified resists have been proposed so far, such as onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, Diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators and the like are known.
Currently, an onium salt-based acid generator having an onium ion (cation) such as triphenylsulfonium in the cation portion is used as the acid generator (see, for example, Patent Document 2).

JP 2003-241385 A JP 2005-037888 A

In recent years, the miniaturization of resist patterns has further progressed, and as the demand for high resolution has further increased, various improvements in lithography properties have been demanded. Accordingly, development of a new resist material is desired.
The above-described onium salt acid generator having a cation such as triphenylsulfonium has a relatively high hydrophobicity of the cation, so that it has excellent affinity with a base material component of a resist and solubility in an organic solvent, and lithography characteristics. It is thought that it contributes to the improvement.
However, the higher the cation hydrophobicity, the lower the solubility in an alkaline developer. If the solubility of the acid generator in an alkaline developer is lowered, the acid generator may not be sufficiently dissolved during development, which may cause problems such as defects and pattern tailing. When a defect occurs, there is also a problem that, for example, the ability to remove the pattern space portion is lowered.
The term “defect” as used herein refers to, for example, general defects detected when a developed resist pattern is observed from directly above with a surface defect observation device (trade name “KLA”) manufactured by KLA Tencor. . This defect means, for example, scum after development, bubbles, dust, bridges between resist patterns, uneven color, precipitates, and the like.
Therefore, there is a need for a compound that can achieve both good solubility in a developer and good lithography properties and is useful as an acid generator for a resist composition.
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, and a resist composition containing the acid generator Another object of the present invention is to provide a resist pattern forming method using the resist composition.

  In order to solve the above problems, the present invention employs the following configuration.

  That is, the first aspect of the present invention is a compound represented by the following general formula (b1-11).

［式（ｂ１−１１）中、Ｒ^７”〜Ｒ^９ ”のうちの１つは、下記の一般式（Ｉ−１）〜（Ｉ−１１）でそれぞれ表される基からなる群から選ばれる置換基を有するフェニル基（但し、他の置換基として炭素数１〜５のアルキル基を有していてもよい。）であり、残りの２つは、それぞれフェニル基である。Ｘ⁻はアニオンである。］

Wherein ^(b1-11), one of R 7 "~R ^9" is selected from the group consisting of groups respectively represented by the following general formula (I-1) ~ (I -11) It is a phenyl group having a substituent (however, it may have an alkyl group having 1 to 5 carbon atoms as another substituent), and the remaining two are each a phenyl group . X ⁻ is an anion. ]

[In formulas (I-1) to (I-11), * represents a bond. In formula (I-5), q represents an integer of 1 to 3. ]

  The second aspect of the present invention is an acid generator comprising the compound of the first aspect.

In the present specification and claims, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
Further, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
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.
The “structural unit” means a monomer unit (monomer unit) constituting a polymer compound (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 a resist pattern using the resist composition A forming method can be provided.

≪Resist composition≫
The resist composition according to the first aspect of the present invention comprises a base component (A) (hereinafter referred to as “component (A)”) whose solubility in an alkaline developer is changed by the action of an acid, and an acid upon exposure. Contains the generated acid generator component (B) (hereinafter referred to as “component (B)”).
When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the component (B), and the acid has a solubility in the alkaline developer of the component (A). Change. As a result, while the solubility of the exposed portion of the resist film in the alkali developer changes, the solubility of the unexposed portion in the alkali developer does not change. However, in the case of the negative type, the unexposed portion is dissolved and removed to form a resist pattern.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.
In addition to the components (A) and (B), the resist composition of the present invention preferably further contains a nitrogen-containing organic compound component (D) (hereinafter referred to as “component (D)”). .
In addition to the components (A) and (B), or in addition to the components (A), (B) and (D), the resist composition of the present invention further comprises a fluorine-containing compound component ( F) (hereinafter referred to as “component (F)”).

<(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 includes a low molecular weight organic compound having a molecular weight of 500 or more and less than 2000 (hereinafter referred to as “low molecular compound”) and a high molecular weight resin having a molecular weight of 2000 or more (polymer material). Broadly divided. As the low molecular weight compound, a non-polymer is usually used. In the case of a resin (polymer, copolymer), a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used as the “molecular weight”. Hereinafter, the term “resin” refers to a resin 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 can be used, and a low molecular compound whose alkali solubility is changed by the action of an acid can also be used.

When the resist composition of the present invention is a “negative resist composition”, a base component that is soluble in an alkali developer is used as the component (A), and the negative resist composition further includes a crosslinking agent component. Is blended.
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause cross-linking between the base component and the cross-linking agent component, resulting in poor solubility in an alkali developer. Change. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the negative resist composition on a support is selectively exposed, the exposed portion turns into poorly soluble in an alkaline developer, while not yet exposed. Since the exposed portion remains soluble in the alkali developer and does not change, a resist pattern can be formed by alkali development.
As the component (A) of the negative resist composition, a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”) is usually used.
Examples of the alkali-soluble resin include 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, and JP-A-2005-336442. Alternatively, a resin having a fluorinated alcohol disclosed in JP-A-2006-259582 is preferable because it can form a good resist pattern with little swelling. 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 component, 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 component 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”, the component (A) is a base material component (hereinafter referred to as “(A ′) component”) whose solubility in an alkali developer is increased by the action of acid. Is used).
The component (A ′) is hardly soluble in an alkali developer before exposure. 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 support is selectively exposed, the exposed portion becomes insoluble 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.

In the resist composition of the present invention, the component (A) is preferably a base material component ((A ′) component) whose solubility in an alkaline developer is increased by the action of an acid. That is, the resist composition of the present invention is preferably a positive resist composition.
The component (A ′) may be a resin component (A1) (hereinafter sometimes referred to as “component (A1)”) whose solubility in an alkaline developer is increased by the action of an acid. It may be a low molecular compound component (A2) (hereinafter sometimes referred to as “component (A2)”) whose solubility in an alkali developer increases, 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 singly or in combination of two or more.
In the present invention, the component (A1) preferably has 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 some or all of the hydrogen atoms of 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.

In the resist composition of the present invention, it is particularly preferable that the component (A1) 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 component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
The component (A1) is derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a1) or in addition to the structural units (a1) and (a2). It is preferable to have a structural unit (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, and those that have been proposed as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists can be used. In general, 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, 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)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). 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.
Here, “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.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a lower alkoxy 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 basic ring structure excluding the substituent of the “aliphatic cyclic 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. The “aliphatic cyclic group” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include a group in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. , Groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane or one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. And a group in which a hydrogen atom is removed. Further, a part of the carbon atoms constituting the ring of a group obtained by removing one or more hydrogen atoms from these monocycloalkanes or a group obtained by removing one or more hydrogen atoms from polycycloalkanes are etheric oxygen atoms (- O-) may be substituted.

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 a monovalent aliphatic cyclic group;
(Ii) a group having a monovalent aliphatic cyclic group and a branched alkylene having a tertiary carbon atom bonded thereto, and the like.
(I) Specific examples of the group having a tertiary carbon atom on the ring skeleton of the monovalent aliphatic cyclic group are represented by the following general formulas (1-1) to (1-9). Groups and the like.
(Ii) Specific examples of the group having a monovalent aliphatic cyclic group and a branched alkylene group having a tertiary carbon atom bonded thereto include, for example, the following general formulas (2-1) to (2-1) And the group represented by (2-6).

［式中、Ｒ^１４はアルキル基であり、ｆは０〜８の整数である。］

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

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。］

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

The alkyl group for R ¹⁴ is preferably a linear or branched alkyl group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group and the like, and isopropyl group is most preferable.
f is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and even more preferably 1 or 2.
Examples of the alkyl group for R ^{15 to} R ¹⁶ include the same alkyl groups as those for R ¹⁴ .
In the formulas (1-1) to (1-9) and (2-1) to (2-6), a part of the carbon atoms constituting the ring is substituted with an etheric oxygen atom (—O—). May be.
In formulas (1-1) to (1-9) and (2-1) to (2-6), a hydrogen atom bonded to a carbon atom constituting the ring may be substituted with a substituent. Examples of the substituent include a lower alkyl group, a fluorine atom, and a fluorinated alkyl group.

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、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または低級アルキル基を表し、ｎは０〜３の整数を表し、Ｙは低級アルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or an aliphatic cyclic group. ]

In the formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the lower alkyl group for R ¹ ′ and R ² ′ 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 acid dissociable, dissolution inhibiting group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同じである。］

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

Examples of the lower alkyl group for Y include the same lower alkyl groups as those described above for R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable, dissolution inhibiting group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状若しくは分岐鎖状のアルキル基または水素原子であり；Ｒ^１９は直鎖状、分岐鎖状若しくは環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状若しくは分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represents a linear or branched alkyl group or a hydrogen atom; and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it 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. And the like, in which a hydrogen atom is removed. 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 the formula (p2), R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ¹⁹ is The terminal of R ¹⁷ may be bonded.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  Specific examples of the acetal type acid dissociable, dissolution inhibiting group include groups represented by the following formulas (p3-1) to (p3-12).

［式中、Ｒ^１３は水素原子またはメチル基であり、ｆは前記と同じである。］

[Wherein, R ¹³ represents a hydrogen atom or a methyl group, and f is the same as defined above. ]

  More specifically, examples of the structural unit (a1) include structural units represented by general formula (a1-0-1) shown below, structural units represented by general formula (a1-0-2) shown below, and the like. .

［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；Ｘ^１は酸解離性溶解抑制基であり；Ｙ^２は２価の連結基であり；Ｘ^２は酸解離性溶解抑制基である。］

[Wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; X ¹ is an acid dissociable, dissolution inhibiting group; Y ² is a divalent linking group; X ² is acid dissociable] It is a dissolution inhibiting 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).
Examples of the divalent linking group for Y ² include an alkylene group, a divalent aliphatic cyclic group, and a divalent linking group containing a hetero atom.
As the aliphatic cyclic group, those similar to the explanation of the “aliphatic cyclic group” can be used except that a group in which two or more hydrogen atoms are removed is used.
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, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable. .
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—, “—AO (oxygen atom) —B— (wherein A and B each independently have a substituent) A divalent hydrocarbon group that may be present.) ”And the like.

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”, A and B are each independently a divalent hydrocarbon group which may have a substituent.
The hydrocarbon group having “substituent” 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 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 preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 2 to 5, and most preferably 2.
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 - 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 —; Alkyl trimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH _{3) CH} 2 CH ₂ - alkyl, such as alkyl tetramethylene group such as Such as an alkylene group, and the 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.

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group described above as a chain-like aliphatic group. And a group bonded to the terminal of the aromatic hydrocarbon group or interposed in the middle of the chain-like 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.

  A is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 2 to 5 carbon atoms, and most preferably an ethylene group.

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 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.

Y ² is preferably the alkylene group, divalent aliphatic cyclic group or divalent linking group containing a hetero atom. Among these, a divalent linking group containing a hetero atom is preferable, and a linear group having an oxygen atom as a hetero atom, for example, a group containing an ester bond is particularly preferable.
Among them, a group represented by the above-described —A—O—B— or —A—C (═O) —O—B— is preferable, and in particular, — (CH ₂ ) _x —C (═O) —O— ( CH _{2) y} - group represented by are preferred.
x is an integer of 1 to 5, preferably 1 or 2, and most preferably 1.
y 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は２価の連結基を表し；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 represents a divalent linking group; R is the same as defined above; 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.
In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
In the present invention, since the lithography properties such as resolution and resist pattern shape are particularly excellent, the structural unit represented by the following general formula (a1-0-11) as the structural unit (a1), the following general formula It is preferable to have at least one selected from the group consisting of a structural unit represented by (a1-0-12) and a structural unit represented by the following general formula (a1-0-2).

［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、Ｒ^２１はアルキル基であり、Ｒ^２２は、当該Ｒ^２２が結合した炭素原子と共に脂肪族単環式基を形成する基であり、Ｒ^２３は分岐鎖状のアルキル基であり、Ｒ^２４は、当該Ｒ^２４が結合した炭素原子と共に脂肪族多環式基を形成する基であり、Ｙ^２は２価の連結基であり、Ｘ^２は酸解離性溶解抑制基である。］

[Wherein R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ²¹ is an alkyl group, and R ²² forms an aliphatic monocyclic group together with the carbon atom to which R ²² is bonded. R ²³ is a branched alkyl group, R ²⁴ is a group that forms an aliphatic polycyclic group together with the carbon atom to which R ²⁴ is bonded, and Y ² is a divalent linking group. X ² is an acid dissociable, dissolution inhibiting group. ]

In each formula, the description of R, Y ² and X ² is the same as described above.
In formula (a1-0-11), examples of the alkyl group for R ²¹ include the same alkyl groups as those described above for R ¹⁴ in formulas (1-1) to (1-9). Group is preferred, and ethyl group is most preferred.
R ²² is, the aliphatic monocyclic group formed together with the carbon atom to which R ²² is bonded, the same aliphatic cyclic groups as those in the tertiary alkyl ester-type acid dissociable, monocyclic The thing similar to what is a formula group is mentioned. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably a 3- to 11-membered ring, more preferably a 3- to 8-membered ring, further preferably a 4- to 6-membered ring, and particularly preferably a 5- or 6-membered ring.
In the monocycloalkane, a part of carbon atoms constituting the ring may or may not be substituted with an etheric oxygen atom (—O—).
The monocycloalkane may have a lower alkyl group, a fluorine atom or a fluorinated alkyl group as a substituent.
Examples of R ²² constituting the aliphatic monocyclic group include a linear alkylene group in which an etheric oxygen atom (—O—) may be interposed between carbon atoms.

Specific examples of the structural unit represented by the formula (a1-0-11) include the formulas (a1-1-16) to (a1-1-23), (a1-1-32), and (a1-1 -33). Among these, the following (a1-1) including structural units represented by formulas (a1-1-16) to (a1-1-17) and (a1-1-20) to (a1-1-23) The structural unit represented by -02) is preferable. Moreover, the structural unit represented by the following (a1-1-02 ′) is also preferable.
In each formula, h is preferably 1 or 2, and most preferably 2.

（式中、Ｒ、Ｒ^２１はそれぞれ前記と同じであり、ｈはそれぞれ１〜３の整数である。）

(In the formula, R and R ²¹ are the same as defined above, and h is an integer of 1 to 3, respectively.)

In formula (a1-0-12), as the branched alkyl group for R ²³ , the branched alkyl group described for the alkyl group for R ¹⁴ in formulas (1-1) to (1-9) above. Examples thereof are the same as those described above, and an isopropyl group is most preferable.
R ²⁴ is, the aliphatic polycyclic group formed together with the carbon atom to which R ²⁴ is bonded, the same aliphatic cyclic groups as those in the aforementioned tertiary alkyl ester-type acid dissociable, dissolution inhibiting group, a polycyclic The thing similar to what is a formula group is mentioned.
Specific examples of the structural unit represented by the formula (a1-0-12) include structural units represented by the formulas (a1-1-26) to (a1-1-31).

Examples of the structural unit represented by the formula (a1-0-2) include the structural unit represented by the formula (a1-3) or (a1-4), and particularly represented by the formula (a1-3). Are preferred.
As the structural unit represented by the formula (a1-0-2), in particular, Y ^{2 in} the formula is represented by the above-described —A—O—B— or —A—C (═O) —O—B—. The group which is a group is preferable.
Preferred examples of the structural unit include a structural unit represented by the following general formula (a1-3-01); a structural unit represented by the following general formula (a1-3-02); 3-03); and the like.

（式中、Ｒ、Ｒ^１４は前記と同じであり、Ｒ^１２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。）

(In the formula, R and R ¹⁴ are the same as above, R ¹² is a hydrogen atom or a methyl group, and a is an integer of 1 to 10.)

（式中、Ｒ、Ｒ^１４は前記と同じであり、Ｒ^１２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。）

(In the formula, R and R ¹⁴ are the same as above, R ¹² is a hydrogen atom or a methyl group, a is an integer of 1 to 10, and n ′ is an integer of 0 to 3.)

［式中、Ｒは前記と同じであり、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 the same as defined above, Y ² ′ and Y ² ″ each independently represent a divalent linking group, X ′ represents an acid dissociable, dissolution inhibiting group, and n represents 0 to 3] It is an integer.]

In formulas (a1-3-01) to (a1-3-02), R ¹² is preferably a hydrogen atom.
a is preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and most preferably 1 or 2.
n ′ is preferably 1 or 2, and most preferably 2.
Specific examples of the structural unit represented by the formula (a1-3-01) include structural units represented by the formulas (a1-3-25) to (a1-3-26).
Specific examples of the structural unit represented by the formula (a1-3-02) include structural units represented by the formulas (a1-3-27) to (a1-3-28).

In formula (a1-3-03), examples of the divalent linking group for Y ² ′ and Y ² ″ include the same groups as those described above for Y ² in formula (a1-3).
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.
Examples of the acid dissociable, dissolution inhibiting group in X ′ include the same groups as described above, and are preferably tertiary alkyl ester type acid dissociable, dissolution inhibiting groups, and (i) the monovalent aliphatic cyclic group described above. A group having a tertiary carbon atom on the ring skeleton of the group is more preferable, and 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 preferable. Among these, the structural unit represented by the formula (a1-3-03-1) is preferable, and the structural units represented by the formulas (a1-3-29) to (a1-3-32) are particularly preferable.

［式中、ＲおよびＲ^１４はそれぞれ前記と同じであり、ａは１〜１０の整数であり、ｂは１〜１０の整数であり、ｔ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 t is an integer of 0 to 3, respectively. ]

a is preferably an integer of 1 to 5, and 1 or 2 is particularly preferable.
b is preferably an integer of 1 to 5, and 1 or 2 is particularly preferable.
t is preferably an integer of 1 to 3, and 1 or 2 is particularly preferable.

In the present invention, the component (A1) preferably has at least two structural units (a1). Lithographic properties are further improved by using a combination of two or more structural units (a1).
In this case, at least one of the at least two types is a structural unit represented by the general formula (a1-0-11), a structural unit represented by the general formula (a1-0-12), and the It is preferably at least one selected from the group consisting of structural units represented by general formula (a1-0-2).
In this case, the at least two kinds of structural units (a1) are structural units represented by the general formula (a1-0-11), structural units represented by the general formula (a1-0-12), and It may be comprised only from what is selected from the group which consists of a structural unit represented by general formula (a1-0-2), At least 1 sort (s) of these structural units, and a structural unit (a1) which does not correspond to these It may be a combination.

Structural unit represented by general formula (a1-0-11), structural unit represented by general formula (a1-0-12), and structural unit represented by general formula (a1-0-2) A structural unit that can be used in combination with at least one selected from the group consisting of, and the structural unit (a1) not corresponding to these is exemplified as a specific example of the general formula (a1-1), The structure represented by the following general formula (a1-1-01) including formulas (a1-1-1) to (a1-1-2) and (a1-1-7) to (a1-1-15) Examples thereof include a unit, a structural unit represented by the general formula (a1-2), and a structural unit represented by the general formula (a1-4).
As the structural unit represented by the general formula (a1-1-01), in particular, the following general formula (a1-1-1-) encompassing the formula (a1-1-1) to the formula (a1-1-2). 101) is preferred.

［式中、Ｒは前記と同じであり、Ｒ^２５およびＲ^１１はそれぞれ独立に炭素数１〜５の直鎖状のアルキル基であり、Ｒ^２４は前記と同様である。］

[Wherein, R is the same as defined above, R ²⁵ and R ¹¹ each independently represent a linear alkyl group having 1 to 5 carbon atoms, and R ²⁴ is the same as defined above. ]

  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, and when it is only the lactone ring, it is called a monocyclic group, and 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, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, such as a group obtained by removing one hydrogen atom from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed, and a group in which one hydrogen atom has been removed from δ-valerolactone. 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’はそれぞれ独立に水素原子、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、Ｒ”は水素原子またはアルキル基であり；Ｒ^２９は単結合または２価の連結基であり、ｓ”は０または１〜２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り；ｍは０または１の整数である。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ′ each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or —COOR; R "is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group; s" is 0 or an integer of 1 to 2; A "is an oxygen atom or a sulfur atom. An alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom, and m is an integer of 0 or 1. ]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
Examples of the alkyl group having 1 to 5 carbon atoms of R ′ include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms of R ′ include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.
R ′ is preferably a hydrogen atom in view of industrial availability.
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 a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
R ²⁹ is a single bond or a divalent linking group. The divalent linking group is the same as the divalent linking group described for Y ² in the general formula (a1-0-2), and among them, an alkylene group and an ester bond (—C (═O ) -O-) or a combination thereof. The alkylene group as the divalent linking group for R ²⁹ is more preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group for A in Y ² can be used.
s ″ is preferably an integer of 1 to 2.
Specific examples of the structural units represented by the general formulas (a2-1) to (a2-5) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

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.
In the present invention, the component (A1) is particularly composed of a structural unit represented by the general formula (a2-1) and a structural unit represented by the general formula (a2-2) as the structural unit (a2). It is preferable to have at least one selected from the group.

  The proportion of the structural unit (a2) in the component (A1) is such that the resist film formed using the resist composition containing the component (A1) adheres to a support such as a substrate and has an affinity for a developer. Since it is excellent in property etc., it is preferable that it is 1-50 mol% or more with respect to all the structural units which comprise (A1) component, 5-50 mol% is more preferable, and 10-45 mol% is further 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 part of hydrogen atoms of an alkyl group is substituted with a fluorine atom, and a hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a 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) ) And the structural unit represented by (a3-4) are preferable.

（式中、Ｒは前記と同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数であり、ｄは１〜３の整数であり、ｅは０または１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) S is an integer of 1 to 3, d is an integer of 1 to 3, and e is 0 or 1.)

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.

  In formula (a3-4), d is preferably 1 or 2, and more preferably 1. The bonding position of the hydroxyl group is not particularly limited. When d is 1, the 2nd position is preferable because it is readily available and inexpensive. When d is 2 or 3, arbitrary substitution positions can be combined.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a3) in the component (A1) 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%. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) is sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

(Other structural units)
The component (A1) may contain other structural units other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
Such other structural units are not particularly limited as long as they are other structural units not classified into the above structural units (a1) to (a3). For ArF excimer lasers and KrF excimer lasers (preferably ArF excimers) A number of hitherto known materials can be used for resist resins such as lasers.

Structural Unit (a4) As such other structural unit, for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group (hereinafter referred to as “structural unit (a4)”). Is preferred. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by 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 proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). -20 mol% is more preferable.

-About structural unit (a0) Moreover, as this other structural unit, the structural unit (a0) represented by the following general formula (a0-1) is also preferable.

［式（ａ０−１）中、Ｒは水素原子、炭素数１〜５の低級アルキル基又は炭素数１〜５のハロゲン化低級アルキル基であり、Ｒ^２は２価の連結基であり、Ｒ^３はその環骨格中に−ＳＯ_２−を含む環式基である。］

[In the formula (a0-1), R is a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms or a halogenated lower alkyl group having 1 to 5 carbon atoms, R ² is a divalent linking group, R ³ is a cyclic group containing —SO ₂ — in the ring skeleton. ]

In the formula (a0-1), R represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated lower alkyl group having 1 to 5 carbon atoms.
The lower alkyl group for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, or an isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
The halogenated lower alkyl group for R is a group in which part or all of the hydrogen atoms of the lower alkyl group have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
R is preferably a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group, and most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

In Formula (a0-1), R ² is a divalent linking group.
Preferred examples of R ² include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom.

.. About the divalent hydrocarbon group which may have a substituent In R ² , the hydrocarbon group “has a substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are It means substituted with a group or atom other than a hydrogen atom.
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 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The 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.

Examples of the aliphatic hydrocarbon group including a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group includes the chain described above. And a group that is bonded to the terminal of the chain-like aliphatic hydrocarbon group or intervenes in the middle of the chain-like 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.

Examples of the aromatic hydrocarbon group include aromatics of monovalent aromatic hydrocarbon groups such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. A divalent aromatic hydrocarbon group obtained by removing one hydrogen atom from the nucleus of the aromatic hydrocarbon;
An aromatic hydrocarbon group in which a part of carbon atoms constituting the ring of the divalent aromatic hydrocarbon group is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom;
An arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., and a hydrogen atom from the nucleus of the aromatic hydrocarbon In addition, an aromatic hydrocarbon group or the like from which one is removed may be mentioned.
The aromatic 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.

.. About the divalent linking group containing a hetero atom In R ² , the hetero atom in the “divalent linking group containing a hetero atom” is an atom other than a carbon atom and a hydrogen atom, such as an oxygen atom, a nitrogen atom, A sulfur atom, a halogen atom, etc. are mentioned.
Specific examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —, —C (═O) —O—, and a carbonate bond (—O—C (═O) —. O-), -NH-, ^-NR04 ( ^R04 is an alkyl group)-, -NH-C (= O)-, = N- and the like. Moreover, the combination etc. of these "divalent coupling groups containing a hetero atom" and a bivalent hydrocarbon group are mentioned. 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.

R ² may or may not have an acid dissociable site in its structure.
The “acid-dissociable site” refers to a site in the organic group that is dissociated by the action of an acid generated by exposure. When R ² has an acid dissociable portion, it is preferable that it preferably has an acid dissociable portion having a tertiary carbon atom.

In the present invention, the divalent linking group for R ² is preferably an alkylene group, a divalent aliphatic cyclic group or a divalent linking group containing a hetero atom. Among these, an alkylene group is particularly preferable.
When R ² is an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms. It is most preferable that it is number 1-3. Specific examples include the same linear alkylene groups and branched alkylene groups as mentioned above.
When R ² is a divalent aliphatic cyclic group, the aliphatic cyclic group is the same as the cyclic aliphatic hydrocarbon group mentioned in the above “aliphatic hydrocarbon group containing a ring in the structure”. Can be mentioned.
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 R ² is a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C (═O) —O—, —C (═O) —, —O—C. (═O) —O—, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group or an acyl group.
_{), - S -, - S} (= O) 2 -, - S (= O) 2 -O-, wherein -A-O-B-, a group represented by the formula - [A-C (= O ) Group represented by -O] _u- B-, etc. are mentioned. Here, A and B are each independently a divalent hydrocarbon group which may have a substituent, and u is an integer of 0 to 3.
When R ² is —NH—, H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
In —A—O—B— or — [A—C (═O) —O] _u —B—, A and B are each independently a divalent hydrocarbon which may have a substituent. It is a group.
As the divalent hydrocarbon group which may have a substituent in A and B, “the divalent hydrocarbon group which may have a substituent” of A and B in the description of Y ² above. The thing similar to what was mentioned as is mentioned.
A is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. .
B is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a 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] _u —B—, u 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 formula (a0-1), R ³ is a cyclic group containing —SO ₂ — in the ring skeleton.
The cyclic group in R ³ represents a cyclic group containing a ring containing —SO ₂ — in the ring skeleton, and the ring is counted as the first ring. When the group has another ring structure, it is called a polycyclic group regardless of the structure. The cyclic group for R ³ may be a monocyclic group or a polycyclic group.
R ³ particularly preferably has a cyclic group containing —O—SO ₂ — in its ring skeleton, that is, a sultone ring.
The cyclic group for R ³ preferably has 3 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 4 to 15 carbon atoms, and particularly preferably 4 to 12 carbon atoms.
However, the carbon number is the number of carbon atoms constituting the ring skeleton, and does not include the carbon number in the substituent.
The cyclic group for R ³ may be an aliphatic cyclic group or an aromatic cyclic group.
An aliphatic cyclic group is preferable.
As the aliphatic cyclic group for R ^3, a carbon atom constituting a ring skeleton of the cyclic aliphatic hydrocarbon group mentioned above is partially substituted with —SO ₂ — or —O—SO ₂ —. Is mentioned.
More specifically, for example, the monocyclic group includes a group obtained by removing one hydrogen atom from a monocycloalkane in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —, and the ring And a group obtained by removing one hydrogen atom from a monocycloalkane in which —CH ₂ —CH ₂ — constituting R ₁ is substituted with —O—SO ₂ —. The polycyclic group includes one hydrogen atom from a polycycloalkane (bicycloalkane, tricycloalkane, tetracycloalkane, etc.) in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —. And a group obtained by removing one hydrogen atom from a polycycloalkane in which —CH ₂ —CH ₂ — constituting the ring is substituted with —O—SO ₂ —.

The cyclic group for R ³ may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, —OC (═O) R ″, a hydroxyalkyl group, a cyano group, and the like. Is mentioned. R ″ is the same as R ″ described above and represents a hydrogen atom or an alkyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group for the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
Examples of the halogenated alkyl group as the substituent include a group in which part or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
R ″ in —COOR ″ and —OC (═O) R ″ is preferably a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group and the like.
The hydroxyalkyl group as the substituent is preferably one having 1 to 6 carbon atoms. Specifically, at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. Group.
More specifically, examples of R ³ include groups represented by the following general formulas (3-1) to (3-4).

［式中、Ａ’は酸素原子若しくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子又は硫黄原子であり；ｚは０〜２の整数であり；Ｒ^６はアルキル基、アルコキシ基、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基又はシアノ基であり、Ｒ”は水素原子又はアルキル基である。］

[Wherein, A ′ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom; z is an integer of 0 to 2; and R ⁶ is an alkyl group. An alkoxy group, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group, and R ″ is a hydrogen atom or an alkyl group.]

In the general formulas (3-1) to (3-4), A ′ represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—), An oxygen atom or a sulfur atom.
The alkylene group having 1 to 5 carbon atoms in A ′ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
A ′ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
z may be any integer from 0 to 2, and is most preferably 0.
When z is 2, the plurality of R ² may be the same or different.
The alkyl group in R ^6, an alkoxy group, a halogenated alkyl group, -COOR ", - OC (= O) R", The hydroxyalkyl groups, respectively, may have the cyclic group in ^{R 3} substituent Examples thereof include the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups mentioned as groups.
Below, the specific cyclic group represented by the said general formula (3-1)-(3-4) is illustrated. In the formula, “Ac” represents an acetyl group.

Among these, R ³ is preferably a group represented by the following general formula (3-1), (3-3) or (3-4), and a group represented by the following general formula (3-1) Is particularly preferred.
Specifically as R ³ , from the group represented by any one of the chemical formulas (3-1-1), (3-1-18), (3-3-1) and (3-4-1) It is more preferable to use at least one selected from the group consisting of: a group represented by the chemical formula (3-1-1) is most preferable.

  In the present invention, the structural unit (a0) is particularly preferably a structural unit represented by the following general formula (a0-1-11).

［式中、Ｒは前記と同じであり、Ｒ^０２は直鎖状または分岐鎖状のアルキレン基であり、Ａ’は前記と同じである。］

[Wherein, R is as defined above, R ⁰² is a linear or branched alkylene group, and A ′ is as defined above. ]

The linear or branched alkylene group for R ⁰² preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 1 to 5, particularly preferably 1 to 3, 2 is most preferred.
A ′ is preferably a methylene group, an oxygen atom (—O—) or a sulfur atom (—S—).

As the structural unit (a0), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a0) in the component (A1) is such that the MEF (mask error factor) when forming a resist pattern using the resist composition containing the component (A1), the resist pattern to be formed Since it is excellent in shape (for example, rectangularity in the case of a line pattern, roundness in the case of a hole pattern, etc.), CDU (in-plane uniformity), LWR (line width roughness), etc., all the components constituting the component (A1) It is preferable that it is 1-60 mol% with respect to a structural unit, 5-50 mol% is more preferable, 10-40 mol% is further more preferable, and 20-40 mol% is the most preferable.

In the present invention, the component (A1) is preferably a polymer having the structural unit (a1).
Examples of the polymer include a copolymer composed of the structural unit (a1) and the structural unit (a2), a copolymer composed of the structural unit (a1) and the structural unit (a3); a structural unit (a1), and a structural unit. A copolymer comprising (a2) and the structural unit (a3); a copolymer comprising the structural unit (a1), the structural unit (a2), the structural unit (a3) and the structural unit (a4); a structural unit (a0) and A copolymer comprising (a1), a copolymer comprising structural units (a0), (a1) and (a2); a copolymer comprising structural units (a0), (a1) and (a3); Examples thereof include a copolymer comprising a0), (a1), (a2) and (a3).

In the resist composition of the present invention, in particular, these copolymers contain, as the structural unit (a1), a structural unit represented by the general formula (a1-0-11), a general formula (a1-0-12). And at least one selected from the group consisting of structural units represented by general formula (a1-1-01).
In addition, as described above, the copolymer preferably includes at least two structural units (a1), and at least one of the at least two structural units is represented by the general formula (a1-0-11). A structural unit selected from the group consisting of the structural unit represented by formula (a1-0-12) and the structural unit represented by formula (a1-0-12), both of which are selected from the group It is more preferable that

In addition, since the component (A1) is excellent in various lithography properties, the total proportion of the structural unit (a0) and the structural unit (a2) (the structural unit (a0 in the case where the structural unit (a2) is not included). ) Only) is preferably 1 to 70 mol%, more preferably 5 to 70 mol%, and more preferably 10 to 65 mol% with respect to all structural units constituting the component (A1). More preferably, 20 to 65 mol% is most preferable. By setting the above range, for example, the exposure margin (EL margin), MEF, CDU, and pattern shape are further improved.
When the component (A1) contains both the structural unit (a0) and the structural unit (a2), the proportion of the structural unit (a0) and the structural unit (a2) in the component (A1) is the structural unit (a0). Is preferably 1 to 40 mol%, more preferably 10 to 35 mol%, most preferably 15 to 30 mol%, and the structural unit (a2) is preferably 1 to 45 mol%, more preferably 10 to 45 mol%, 20 to 45 mol% is most preferable.

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. If it is smaller than the upper limit of this range, there is sufficient solubility in a resist solvent to be used as a resist, and if 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.

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 proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, and 100% by mass with respect to the total mass of the component (A). May be. When the ratio is 25% by mass or more, effects such as lithography characteristics are improved.

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 an 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
A commercially available monomer may be used as the monomer for deriving each structural unit, or the monomer may be synthesized using a known method.
For example, as a monomer for deriving the structural unit (a0), a compound represented by the following general formula (a0-1-0) (hereinafter referred to as “compound (a0-1-0)”) can be mentioned.

［式（ａ０−１−０）中、Ｒ、Ｒ^２、Ｒ^３はそれぞれ前記と同じである。］

[In the formula (a0-1-0), R, R ² and R ³ are the same as defined above. ]

The manufacturing method of this compound (a0-1-0) is not specifically limited, It can manufacture using a well-known method.
For example, in the presence of a base, a compound (X-) represented by the following general formula (X-2) is added to a solution in which the compound (X-1) represented by the following general formula (X-1) is dissolved in the reaction solvent. The compound (a0-1-0) is obtained by adding and reacting 2).
Examples of the base include inorganic bases such as sodium hydride, K ₂ CO ₃ and Cs ₂ CO ₃ ; organic bases such as triethylamine, 4-dimethylaminopyridine (DMAP) and pyridine. Examples of the condensing agent include carbodiimide reagents such as ethyldiisopropylaminocarbodiimide (EDCI) hydrochloride, dicyclohexylcarboimide (DCC), diisopropylcarbodiimide, carbodiimidazole, tetraethylpyrophosphate, benzotriazole-N-hydroxytrisdimethylaminophosphonium hexa Fluorophosphide salt (Bop reagent) and the like.
Moreover, you may use an acid as needed. As the acid, those usually used in dehydration condensation and the like can be used. Specifically, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p- Organic acids such as toluenesulfonic acid can be mentioned. These may be used alone or in combination of two or more.

[(A2) component]
As the component (A2), a low molecular compound having a molecular weight of 500 or more and less than 2000 and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of the component (A1) above is preferable. 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, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, 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, Examples include 2, 3, 4 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol or xylenol. 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.
(A2) A component may be used individually by 1 type and may be used in combination of 2 or more type.

In the resist composition of the present invention, as the component (A), one type may be used alone, or two or more types may be used in combination.
Among the above, the component (A) preferably contains 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>
The resist composition of the present invention contains an acid generator component (B) that generates an acid upon exposure, and the component (B) is a compound having a group represented by the following general formula (I) in the cation moiety. Acid generator (B1) (hereinafter referred to as “component (B1)”).

［式（Ｉ）中、Ｒ^５は水素原子又は置換基を有していてもよい炭素数１〜３０の有機基であり、Ｑ^５は単結合又は２価の連結基である。］

[In Formula (I), R ⁵ is a hydrogen atom or an organic group having 1 to 30 carbon atoms which may have a substituent, and Q ⁵ is a single bond or a divalent linking group. ]

In said formula (I), R < ⁵ > is a C1-C30 organic group which may have a hydrogen atom or a substituent.

In the general formula (I), the organic group represented by R ⁵ may be an aromatic hydrocarbon group, an aliphatic hydrocarbon group, or another cyano group (—CN). .

The aliphatic hydrocarbon group for R ⁵ is, for example, a linear, branched or cyclic saturated hydrocarbon group having 1 to 15 carbon atoms, or a linear or branched chain group having 2 to 5 carbon atoms. An aliphatic unsaturated hydrocarbon group is mentioned.

Examples of the linear saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decanyl group.
Examples of the branched saturated hydrocarbon group include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group. 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.
The linear or branched alkyl group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), a cyano group, and a carboxy group.
As the alkoxy group as a substituent of the linear or branched alkyl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n- A butoxy group and a tert-butoxy group are preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent of the linear or branched alkyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
The halogenated alkyl group as a substituent for the aromatic group is a hydrogen atom of an alkyl group having 1 to 5 carbon atoms (preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc.). Examples thereof include a group in which part or all of the atoms are substituted with the halogen atom.

The cyclic saturated hydrocarbon group may be either a polycyclic group or a monocyclic group, and examples thereof include cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as monocycloalkane, bicycloalkane, and tricyclo. And groups obtained by removing one hydrogen atom from polycycloalkane such as alkane and tetracycloalkane. More specifically, one hydrogen atom was removed from a monocycloalkane such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group and the like.
The cyclic alkyl group may have a substituent. For example, part of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with a heteroatom, or the hydrogen atom bonded to the ring of the cyclic alkyl group may be substituted with a substituent. Good.
Examples of the former include one or more hydrogen atoms from a heterocycloalkane in which a part of the carbon atoms constituting the ring of the monocycloalkane or polycycloalkane is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Examples include groups other than atoms. The ring structure may have an ester bond (—C (═O) —O—). Specifically, a lactone-containing monocyclic group such as a group obtained by removing one hydrogen atom from γ-butyrolactone, or a group obtained by removing one hydrogen atom from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring. And other lactone-containing polycyclic groups.
Examples of the substituent in the latter example include the same as those exemplified as the substituent that the linear or branched alkyl group may have, an alkyl group having 1 to 5 carbon atoms, and the like.

Examples of the linear unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group.
Examples of the branched unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
The linear or branched unsaturated hydrocarbon group may have a substituent. Examples of the substituent include the same ones as those exemplified as the substituent which the linear or branched alkyl group may have.

The aromatic hydrocarbon group for R ⁵ 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.
The aromatic organic group may have an aromatic hydrocarbon ring in which the ring skeleton of the aromatic ring is composed only of carbon atoms, and the aromatic ring group includes aromatic atoms containing hetero atoms other than carbon atoms. It may have a heterocyclic ring.
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. A heteroaryl group in which a part of carbon atoms constituting the ring of these aryl groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom; a benzyl group, a phenethyl group, 1 -Arylalkyl groups such as naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, and the like. 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 a heteroaryl group in which a part of carbon atoms constituting the ring of the aryl group is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, or a carbon constituting the ring of the arylalkyl group. Examples include heteroarylalkyl groups in which a part of the atoms is substituted with the heteroatom.
Examples of the substituent of the aromatic 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), and an acetyl group.
Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the aromatic group include those mentioned as the substituent that the linear or branched alkyl group may have. The same thing and a C1-C5 alkyl group are mentioned.

Among the above, the hydrocarbon group of R ⁵ is preferably an aliphatic hydrocarbon group because it has fewer defects and a resist pattern having a good shape is easily formed, and is linear, branched or cyclic. A saturated hydrocarbon group is more preferable, a linear saturated hydrocarbon group is more preferable, and a linear alkyl group having 1 to 4 carbon atoms is particularly preferable.
The hydrocarbon group for R ⁵ is preferably a bulky group, more preferably an aromatic hydrocarbon group, and particularly preferably a phenyl group.
When R ⁵ is a bulky group, the uniformity of the distribution of the component (B1) within the resist film is further improved. In addition, the effect of inhibiting dissolution of the unexposed portion of the resist film is obtained, and a resist pattern having a better shape can be formed. The reason why such an effect can be obtained is considered to be that when R ⁵ is a bulky group, film loss is suppressed by slowing the dissolution rate in an alkali developer, particularly in an unexposed area.

In the formula (I), Q ⁵ is a single bond or a divalent linking group.
Examples of the divalent linking group for Q ⁵ include an alkylene group and a group containing a hetero atom, and a group containing a hetero atom is preferable because a resist pattern with a better shape can be formed.
The “heteroatom” herein is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a sulfur atom, and a nitrogen atom.
The alkylene group is preferably a linear or branched alkylene group, the alkylene group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and particularly preferably a methylene group, an ethylene group or a propylene group. .
Specific examples of the group containing a hetero atom include an oxygen atom (ether bond; —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH—). , Non-hydrocarbon oxygen such as carbonyl group (—C (═O) —), carbonate bond (—O—C (═O) —O—), thioester bond (—C (═O) —S—), etc. Atom-containing linking group; a combination of the non-hydrocarbon oxygen atom-containing linking group and an alkylene group.
Examples of the combination, for ^{example, -R 97 -O -, - R} 97 -C (= O) -, - R 98 -O-C (= O) -, - R 98 -C (= O) -O- , -R < ⁹⁸ > -S-C (= O)-, -O-R < ⁹⁸ > -O-C (= O)-, -C (= O) -O-R <^99> -O-C (= O)-, -C (= O) -O-R ^99- (wherein R ^{97 to} R ⁹⁹ are each independently an alkylene group).
The alkylene group for R ^{97 to} R ⁹⁹ is preferably a linear or branched alkylene group. 1-10 are preferable, as for carbon number of this alkylene group, 1-7 are more preferable, and 1-5 are especially preferable. As described above, this alkylene group may be a phenylene group or a phenyl group because it is estimated that the same effect as that in the case where R ⁵ is a bulky group is obtained. Good.
Among these, Q ⁵ is preferably a single bond, an ester bond, a thioester bond, a carbonyl group or an ether bond, and a divalent linking group including a single bond, —O—, —R ⁹⁷ —O. —, —R ⁹⁷ —C (═O) —, —O—C (═O) —, —R ⁹⁸ —O—C (═O) —, —R ⁹⁸ —C (═O) —O— or — C (═O) —O—R ⁹⁹ — is more preferred, —R ⁹⁸ —O—C (═O) —, —O—C (═O) — are particularly preferred, and —O—C (═O) —. Is most preferred.

  In the present invention, the component (B1) is not particularly limited as long as it has a group represented by the above general formula (I) in its cation portion, and among them, there are fewer defects and a resist pattern having a good shape. Since it is easy to form, it is preferable that it is a compound represented by the following general formula (b1-11).

［式（ｂ１−１１）中、Ｒ^７”〜Ｒ^９”はそれぞれ独立にアリール基又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、置換基として前記一般式（Ｉ）で表される基を有する置換アリール基である。Ｘ⁻はアニオンである。］

[In formula (b1-11), 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 in the formula A ring may be formed together with the sulfur atom, and at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group having a group represented by the general formula (I) as a substituent. X ⁻ is an anion. ]

In the formula (b1-11), R ⁷ ″ to R ⁹ ″ each independently represents an aryl group or an alkyl group. However, at least one of R ⁷ ″ to R ⁹ ″ is a substituted aryl group having a group represented by the general formula (I) as a substituent.

The aryl group for R ⁷ ″ to R ⁹ ″ 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 have the above general formula. It may or may not be substituted with a substituent other than the substituent represented by (I), for example, an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group and the like.
Such an 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.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Are more preferable, and a methyl group is particularly preferable.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, A tert-butoxy group is more preferable.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.

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. . Among these, a methyl group is preferable because it is more excellent in resolution and can be synthesized at a low cost.

In the formula (b1-11), any two of R ⁷ ″ to R ⁹ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula.
In such a case, it is preferable to form a 3- to 10-membered ring including a sulfur atom, and 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 “substituted aryl group (I)”). It is.
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 general 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 general 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 may be the same as those exemplified as the substituent for 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. In the following formula, q represents an integer of 1 to 3.

-About the anion part of (B1) component In formula (b1-11), the anion of X < ^- > is not specifically limited, What is known as an anion part of an onium salt type | system | group acid generator can be used selecting it suitably. it can.
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 — and the like. Alkylethylene groups; trimethylene groups (n-propylene groups) [—CH ₂ CH ₂ CH ₂ —]; alkyls such as —CH (CH ₃ ) CH ₂ CH ₂ — and —CH ₂ CH (CH ₃ ) CH ₂ — trimethylene; tetramethylene group _[-CH 2 _CH 2 C _{2 CH 2 -]; - CH} (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; pentamethylene group _[-CH 2 _CH 2 CH ₂ CH ₂ CH ₂ —] and the like.
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 be a part of the carbon atom constituting the aliphatic hydrocarbon group may be 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 number of carbon atoms 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 are removed from a monocycloalkane; a group in which one or more hydrogen atoms are 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^７０”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 the same as defined above, q2 is an integer of 0 to 5; R ⁷⁰ ″ represents 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.
The alkyl group, alkoxy group, halogen atom (excluding fluorine atom), halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group of R ⁷⁰ ″ 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 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 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, ^wherein: Z 5 -Q ⁴ - [wherein, ^{Q 4} represents a divalent linking group containing an oxygen atom, ^{Z 5} is a hydrocarbon group of 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 ″.

Z ⁵ -Q ⁴ - In the group represented by, ^{Q 4} represents a divalent linking group containing an oxygen atom.
The Q ^4, the ^{Z-Q 1} - are the same as those for ^{Q 1} in a group represented.
Q ⁴ 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. R ^{91 to} R ⁹³ are the same as described above.
Z ⁵ -Q ⁴ - In the group represented by, ^{Z 5} represents a hydrocarbon group which may 3-30 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、ｒは１〜４の整数であり、ｉ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, r is an integer of 1 to 4, and i 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.
r is preferably 1 or 2, and most preferably 1.
i 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^１８”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^１９”は、置換基を有していてもよい炭化水素基、または−ＳＯ_２−Ｒ^１８”である。］

[Wherein R ¹⁸ ″ is an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with fluorine; R ¹⁹ ″ is a hydrocarbon group which may have a substituent, or —SO ₂ —R ¹⁸ ″.]

In formula (b-c1), R ¹⁸ ″ 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 ¹⁸ ″ is preferably a linear or branched alkyl group, and more preferably a linear alkyl group.
In the formula (b-c1), when R ¹⁹ ″ is a hydrocarbon group which may have a substituent (the “hydrocarbon group which may have a substituent” refers to the hydrocarbon group This means that a part or all of the hydrogen atoms constituting may be substituted with a substituent group.), The hydrocarbon group of R ¹⁹ ″ may be an aliphatic hydrocarbon group or an aromatic carbon group. A hydrogen group may be used, and specific examples include the same as Z in the above formula: ZQ ^1- .
R ¹⁹ ″ is preferably an aryl group having a halogen atom as a substituent (halogenated aryl group) or —SO ₂ —R ¹⁸ ″. 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) may be 100 mass%. When the component (B1) is combined with an acid generator component not corresponding to the component (B1), the proportion of the component (B1) is preferably 1 to 99% by mass, more preferably 10 to 99% by mass, and 20 to 90% by mass. Is more preferable, and 40 to 85% by mass is particularly preferable.
Moreover, the total content of the component (B1) in the resist composition of the present invention is preferably 0.1 to 60 parts by mass, more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the component (A). . When it is at least the lower limit of the above range, there are fewer defects and a resist pattern having a good shape can be easily formed. It is preferable for it to be not more than the upper limit of the above range since a uniform solution can be obtained and the storage stability will be good.

The resist composition of the present invention may contain, as the component (B), an acid generator component (hereinafter referred to as “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, poly (bissulfonyl) diazomethanes, and the like. 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 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) phenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1-phenyltetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 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 symbols 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 Nthenyl 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 18] to [Chemical 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 85 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 the component (B2), among the above, an acid generator having an anion as an anion which is a fluorinated alkyl group in which R ⁴ ″ may have a substituent is preferable. An onium salt acid generator having a good fluorinated alkyl sulfonate ion is more preferable.

When the component (B2) is contained as the component (B), the proportion of the component (B2) in the component (B) is preferably 1 to 90% by mass, more preferably 5 to 70% by mass, and 10 to 60% by mass. Is more preferable.
In the component (B), the ratio (mass ratio) of the blending amount of the component (B1) and the component (B2) is preferably (B1) component: (B2) component = 90: 10 to 10:90, 80:20 to 20:80 is more preferable, 70:30 to 25:75 is more preferable, and 65:35 to 30:70 is particularly preferable.

  The total 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 with respect to 100 parts by mass of the component (A). 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>
[(D) component]
The resist composition of the present invention preferably further contains a nitrogen-containing organic compound component (D) (hereinafter referred to as “component (D)”) as an optional component.
The component (D) is not particularly limited as long as it acts as an acid diffusion controller, that is, a quencher that traps the acid generated from the component (B) by exposure, and a wide variety of components have already been proposed. Therefore, any known one may be used, and aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are particularly 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-pentylamine, tri-n-hexylamine , 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. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

[(F) component]
The resist composition of the present invention may further contain a fluorine-containing compound component (F) (hereinafter referred to as “(F) component”). By containing the component (F), the hydrophobicity of the resist film surface is increased, and a resist composition suitable for immersion exposure can be obtained.
The component (F) is not particularly limited and may be a high molecular weight high molecular compound (polymer, copolymer) composed of repeating structural units, or may be a low molecular weight low molecular compound (non-polymer). May be.
Examples of the component (F) include a polymer compound having a structural unit containing a fluorine atom as a polymer compound (polymer, copolymer), specifically, one type of structural unit containing a fluorine atom or Examples thereof include a polymer compound composed of two or more kinds of repeating; a polymer compound composed of repeating a structural unit containing a fluorine atom and a structural unit not containing a fluorine atom.
In addition, examples of the component (F) include a monomer that derives a structural unit containing a fluorine atom constituting the polymer compound (polymer, copolymer) as a low molecular compound (non-polymer).
Among these, the component (F) is preferably a polymer compound (polymer, copolymer).

-Constituent unit containing fluorine atom (constituent unit (f1)) The constituent unit containing a fluorine atom (hereinafter referred to as "constituent unit (f1)") is not particularly limited as long as it contains a fluorine atom. The fluorine atom may be contained in the side chain, the fluorine atom may be directly bonded to the main chain, or the substituent bonded to the main chain may contain the fluorine atom.
Among these, as the structural unit (f1), one in which a fluorine atom is contained in the side chain is preferable. Specifically, a structural unit containing a group represented by the following general formula (f1-1-0), a structural unit containing an acid dissociable, dissolution inhibiting group-containing group containing a fluorine atom, and a non-acid dissociable carbon number The structural unit containing 1-20 fluorinated alkyl groups is mentioned, The structural unit containing the group represented by general formula (f1-1-0) is more preferable.

［式（ｆ１−１−０）中、Ｒ^８はフッ素原子を有する有機基である。ただし、−Ｃ（＝Ｏ）−の炭素原子は主鎖に直接結合していないものとする。］

[In formula (f1-1-0), R ⁸ represents an organic group having a fluorine atom. However, the carbon atom of —C (═O) — is not directly bonded to the main chain. ]

(Structural unit containing group represented by general formula (f1-1-0))
In the formula (f1-1-0), R ⁸ is an organic group having a fluorine atom.
“Organic group” refers to a group containing at least one carbon atom.
In the organic group having a fluorine atom in R ^8, the structure of R ⁸ may be linear, branched, or cyclic, and is preferably linear or branched.
In R ⁸ , the organic group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and most preferably 1 to 5 carbon atoms.
In R ⁸ , the organic group preferably has a fluorination rate of 25% or more, more preferably 50% or more, and particularly preferably 60% or more because the hydrophobicity of the resist film is increased. .
“Fluorination rate” refers to the ratio (%) of (number of fluorine atoms) to (total number of hydrogen atoms and fluorine atoms) in the organic group.

Specific examples of R ⁸ include a fluorinated hydrocarbon group which may have a substituent.
In the fluorinated hydrocarbon group, the hydrocarbon group (non-fluorinated one) may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an aliphatic hydrocarbon group. It is preferable that
The aliphatic hydrocarbon group is a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be either saturated or unsaturated, and is usually preferably saturated.
That is, R ⁸ is preferably a fluorinated saturated hydrocarbon group or a fluorinated unsaturated hydrocarbon group, and particularly preferably a fluorinated saturated hydrocarbon group, that is, a fluorinated alkyl group.
Examples of the fluorinated alkyl group include groups in which some or all of the hydrogen atoms of the unsubstituted alkyl group (which does not have a substituent described below) are substituted with fluorine atoms.
The fluorinated alkyl group may be a group in which some of the hydrogen atoms of the unsubstituted alkyl group are substituted with fluorine atoms, or a group in which all of the hydrogen atoms of the unsubstituted alkyl group are substituted with fluorine atoms ( Perfluoroalkyl group).

The unsubstituted alkyl group may be linear, branched or cyclic, and may be a combination of a linear or branched alkyl group and a cyclic alkyl group. .
As an unsubstituted linear alkyl group, C1-C10 is preferable and C1-C8 is more preferable. Specifically, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n- A decanyl group etc. are mentioned.
As an unsubstituted branched alkyl group, C3-C10 is preferable and C3-C8 is more preferable. As the branched alkyl group, a tertiary alkyl group is preferable.
Examples of the unsubstituted cyclic alkyl group include groups in which one hydrogen atom has been removed from a monocycloalkane or a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. Specific examples include monocycloalkyl groups such as cyclopentyl group and cyclohexyl group; polycycloalkyl groups such as adamantyl group, norbornyl group, isobornyl group, tricyclodecanyl group, and tetracyclododecanyl group.
The combination of an unsubstituted linear or branched alkyl group and a cyclic alkyl group includes a group in which a cyclic alkyl group is bonded as a substituent to a linear or branched alkyl group, or a cyclic alkyl And a group in which a linear or branched alkyl group is bonded to the group as a substituent.

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

In R ⁸ , the fluorinated alkyl group is preferably a linear or branched fluorinated alkyl group. In particular, a group represented by the following general formula (VII-1) or (VII-2) is preferable, and among them, a group represented by the formula (VII-1) is preferable.

［式（ＶＩＩ−１）中、Ｒ^４１’は無置換の炭素数１〜９のアルキレン基であり、Ｒ^４２’は炭素数１〜９のフッ素化アルキル基である。但し、Ｒ^４１’とＲ^４２’との炭素数の合計は１０以下である。また、式（ＶＩＩ−２）中、Ｒ^８１〜Ｒ^８３は、それぞれ独立に、炭素数１〜５の直鎖状のアルキル基であり、Ｒ^８１〜Ｒ^８３の少なくとも１つはフッ素原子を有するアルキル基である。］

[In Formula (VII-1), R ⁴¹ ′ is an unsubstituted alkylene group having 1 to 9 carbon atoms, and R ⁴² ′ is a fluorinated alkyl group having 1 to 9 carbon atoms. However, the total number of carbon atoms of R ⁴¹ ′ and R ⁴² ′ is 10 or less. In Formula (VII-2), R ^{81 to} R ⁸³ are each independently a linear alkyl group having 1 to 5 carbon atoms, and at least one of R ^{81 to} R ⁸³ has a fluorine atom. It is an alkyl group. ]

In formula (VII-1), the alkylene group for R ⁴¹ ′ may be linear, branched or cyclic, and is preferably linear or branched. Moreover, as for the carbon number, 1-5 are preferable.
R ⁴¹ ′ is particularly preferably a methylene group, an ethylene group or a propylene group.
As R ⁴² ′, a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a perfluoroalkyl group is particularly preferable. Of these, a trifluoromethyl group and a pentafluoroethyl group are preferable.
In formula (VII-2), the alkyl groups represented by R ^{81 to} R ⁸³ are each preferably an ethyl group or a methyl group, and particularly preferably a methyl group. Any one of the alkyl groups of R ^{81 to} R ⁸³ may be a fluorinated alkyl group, and all may be a fluorinated alkyl group.

However, in the formula (f1-1-0), the carbon atom of —C (═O) — is not directly bonded to the main chain. Accordingly, the group “—O—R ⁸ ” can be sufficiently dissociated by the action of the weakly basic alkaline developer.
That is, “—O—R ⁸ ” is hydrolyzed by the action of an alkali developer and dissociates from the group represented by the general formula (f1-1-0). Therefore, in the group represented by the general formula (f1-1-0), the hydrophilic group [—C (═O) —OH] is formed simultaneously with the dissociation of “—O—R ⁸ ”. And the hydrophilicity of (F) component increases and the affinity with respect to an alkali developing solution improves. This increases the hydrophilicity of the resist film surface during development.

  In the resist composition of the present invention, as the structural unit (f1), the solubility in an organic solvent is good and the hydrophobicity of the resist film surface is higher. Therefore, the structural unit (f1-1) is represented by the following general formula (f1-1-1). The structural unit (f1-1) represented is mentioned as a suitable thing.

［式（ｆ１−１−１）中、Ｒは水素原子、炭素原子数１〜５の低級アルキル基、又は炭素原子数１〜５のハロゲン化低級アルキル基であり；Ｑ^０は単結合又は二価の連結基であり、Ｒ^８はフッ素原子を有する有機基である。］

[In the formula (f1-1-1), R is a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated lower alkyl group having 1 to 5 carbon atoms; Q ⁰ is a single bond or two R ⁸ is an organic group having a fluorine atom. ]

... About structural unit (f1-1) A structural unit (f1-1) is a structural unit represented by the said general formula (f1-1-1).
In the formula (f1-1-1), R represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated lower alkyl group having 1 to 5 carbon atoms.
The lower alkyl group or halogenated lower alkyl group for R is the same as the lower alkyl group or halogenated lower alkyl group which may be bonded to the α-position of the acrylate ester.

In Formula (f1-1-1), Q ⁰ is a single bond or a divalent linking group.
Preferred examples of the divalent linking group for Q ⁰ include a hydrocarbon group which may have a substituent, a group containing a hetero atom, and the like.

(Hydrocarbon group which may have a substituent)
In the divalent linking group for Q ⁰ , the hydrocarbon group “has a substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms. Means.
The hydrocarbon group for Q ⁰ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
The term “aliphatic hydrocarbon group” as used herein means a hydrocarbon group having no aromaticity. Such an 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, and an aliphatic hydrocarbon group containing a ring in the structure thereof.

The linear or branched aliphatic hydrocarbon group for Q ⁰ preferably has 1 to 10 carbon atoms, more preferably 1 to 8, more preferably 1 to 5, and particularly preferably 1 to 3. 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 - 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 —; Alkyl trimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH _{3) CH} 2 CH ₂ - alkyl, such as alkyl tetramethylene group such as Such as an alkylene group, and the like. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like (straight chain or branched chain) aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (═O), and the like.

Examples of the aliphatic hydrocarbon group containing a ring in Q ⁰ include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) and the cyclic aliphatic hydrocarbon group described above. Examples thereof include a group bonded to the terminal of a chain aliphatic hydrocarbon group or interposed in the middle of a 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 or more hydrogen atoms are 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 or more hydrogen atoms have been removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, And tetracyclododecane.
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.

Examples of the aromatic hydrocarbon group in Q ⁰ include monovalent aromatic hydrocarbons such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. A divalent aromatic hydrocarbon group obtained by removing one more hydrogen atom from the nucleus of the aromatic hydrocarbon of the group;
An aromatic hydrocarbon group in which a part of carbon atoms constituting the ring of the divalent aromatic hydrocarbon group is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom;
Benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc., and 1 more hydrogen atom from the aromatic hydrocarbon nucleus Aromatic hydrocarbon groups and the like removed.
Among them, the divalent aromatic hydrocarbon group is preferable, and an aromatic hydrocarbon group in which one hydrogen atom is further removed from a phenyl group, and an aromatic hydrocarbon group in which one hydrogen atom is further removed from a naphthyl group are particularly preferable. preferable.
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 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.

Among the above, the hydrocarbon group which may have a substituent is preferably a linear, branched or cyclic aliphatic hydrocarbon group, or a divalent aromatic hydrocarbon group, more preferably a methylene group. , An ethylene group, —CH (CH ₃ ) —, a group obtained by further removing one hydrogen atom from a tetracyclododecanyl group, and an aromatic hydrocarbon group obtained by further removing one hydrogen atom from a phenyl group are particularly preferred.

(Groups containing heteroatoms)
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.
Examples of the group containing a hetero atom include -O-, -C (= O)-, -C (= O) -O-, carbonate bond (-O-C (= O) -O-), -NH. ^-, - NR ^{05 (R} 05 is an alkyl group) -, - NH-C ( = O) -, = N-, or a combination of the "these groups" with a divalent hydrocarbon group.
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.
Among them, the group containing a hetero atom is more preferably a combination of the “these groups” and a divalent hydrocarbon group. Specifically, the “these groups” and the aliphatic hydrocarbon group The combination of the above aliphatic hydrocarbon group, the above “these groups”, and the above aliphatic hydrocarbon group is particularly preferable.

In the formula (f1-1-1), R ⁸ is an organic group having a fluorine atom, and is the same as R ⁸ in the formula (f1-1-0).

  Preferable examples of the structural unit (f1-1) include structural units represented by general formula (f1-1-10) or general formula (f1-1-20) shown below.

［式中、Ｒはそれぞれ独立して水素原子、炭素原子数１〜５の低級アルキル基、又は炭素原子数１〜５のハロゲン化低級アルキル基であり；Ｘは二価の有機基であり、Ａ_ａｒｙｌは置換基を有していてもよい二価の芳香族環式基であり、Ｘ_０１は単結合又は二価の連結基であり；Ｒ^８はそれぞれ独立してフッ素原子を有する有機基である。］

Wherein R is independently a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated lower alkyl group having 1 to 5 carbon atoms; X is a divalent organic group; A _aryl is a divalent aromatic cyclic group which may have a substituent, X ₀₁ is a single bond or a divalent linking group; R ⁸ is an organic group each independently having a fluorine atom It is. ]

In formula (f1-1-10) or (f1-1-20), R ⁸ is the same as defined above.
In Formula (f1-1-10) or (f1-1-20), R ⁸ is preferably a fluorinated hydrocarbon group, more preferably a fluorinated alkyl group, and a fluorinated alkyl group having 1 to 5 carbon atoms. more _{preferably, -CH 2 -CF 3, -CH 2} -CF 2 -CF 3, -CH (CF 3) 2, -CH 2 -CF 2 -CF 2 -CF 3, -CH 2 -CH 2 -CF 2 -CF ₂ -CF _3, is _{-CH 2 -CH 2 -CF 2 -CF 2} -CF 2 -CF 3 particularly preferred.

The lower alkyl group in R is preferably linear or branched, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, An isopentyl group, a neopentyl group, etc. are mentioned.
Specific examples of the halogenated lower alkyl group include groups in which some or all of the hydrogen atoms of the “lower alkyl group” have been 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, R is preferably a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group, and more preferably a hydrogen atom or a methyl group in terms of industrial availability.

In general formula (f1-1-10), X represents a divalent organic group.
X is preferably a hydrocarbon group which may have a substituent, a group containing a hetero atom, etc., each having a substituent in the description of the divalent linking group of Q ⁰ above. And the same hydrocarbon groups and hetero atom-containing groups as those mentioned above.

In general formula (f1-1-20), A _aryl is a divalent aromatic cyclic group which may have a substituent. Specific examples of A _aryl include a group in which two or more hydrogen atoms have been removed from an aromatic hydrocarbon ring which may have a substituent.
The ring skeleton of the aromatic cyclic group in A _aryl preferably has 6 to 15 carbon atoms, and examples thereof include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. Among these, a benzene ring or a naphthalene ring is particularly preferable.
In A _aryl , examples of the substituent that the aromatic cyclic group may have include a halogen atom, an alkyl group, an alkoxy group, a halogenated lower alkyl group, and an oxygen atom (═O). Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. The substituent that the aromatic cyclic group of A _aryl may have is preferably a fluorine atom.
The aromatic cyclic group of A _aryl may have no substituent, may have a substituent, and preferably has no substituent.
In A _aryl , when the aromatic cyclic group has a substituent, the number of substituents may be one, two or more, and one or two. Is preferable, and one is more preferable.

In general formula (f1-1-20), X ₀₁ represents a single bond or a divalent linking group.
Examples of the divalent linking group include an alkylene group having 1 to 10 carbon atoms, —O—, —C (═O) —, —C (═O) —O—, and a carbonate bond (—O—C (═O). -O-), -NH-C (= O)-, or a combination of these, and the combination of -O- and an alkylene group having 1 to 10 carbon atoms, -C (= O) -O- and A combination with an alkylene group having 1 to 10 carbon atoms is more preferred.
Examples of the alkylene group having 1 to 10 carbon atoms include linear, branched or cyclic alkylene groups, linear or branched alkylene groups having 1 to 5 carbon atoms, and 4 to 10 carbon atoms. A cyclic alkylene group is preferred.

Among the structural units represented by the general formula (f1-1-10), structural units represented by the following general formulas (f1-1-11) to (f1-1-16) are listed. It is done.
Moreover, as a suitable unit among the structural units represented by the general formula (f1-1-20), structural units represented by the following general formulas (f1-1-21) to (f1-1-26) Is mentioned.

In the general formulas (f1-1-11) to (f1-1-16) and (f1-1-21) to (f1-1-26), R and R ⁸ are the same as defined above; R ⁵¹ to R ⁵² are each independently an alkyl group having 1 to 10 carbon ^atoms; R 53 ^{to R 54} are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; a1, a2, a3, a5 , A7, a9 and a11 to a13 are each independently an integer of 1 to 5; a4, a6, a8 and a10 are each independently an integer of 0 to 5; a14 to a16 are 0 to 5 be an integer; b1-b5 are each independently 0 or 1; ^{R 9} both are substituents, e1 is an integer of 0-2. A ₁ is a cyclic alkylene group having 4 to 20 carbon atoms.

  In formulas (f1-1-11) to (f1-1-16) and (f1-1-21) to (f1-1-26), R is preferably a hydrogen atom or a methyl group.

In formula (f1-1-11), a1 is preferably an integer of 1 to 3, and more preferably 1 or 2.
In formula (f1-1-12), a2 and a3 are each independently preferably an integer of 1 to 3, and more preferably 1 or 2.
b1 is preferably 0.

In formula (f1-1-13), a4 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and most preferably 0 or 1.
a5 is preferably an integer of 1 to 3, and more preferably 1 or 2.
Examples of the substituent for R ⁹ include a halogen atom, a lower alkyl group, an alkoxy group having 1 to 5 carbon atoms, a halogenated lower alkyl group, and an oxygen atom (═O). Examples of the lower alkyl group include the same lower alkyl groups as those described above for R. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. Examples of the halogenated lower alkyl group include the same halogenated lower alkyl groups as those described above for R.
e1 is preferably 0 or 1, particularly preferably 0 from an industrial viewpoint.
b2 is preferably 0.
In formula (f1-1-14), a6 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and most preferably 0 or 1.
a7 is preferably an integer of 1 to 3, and more preferably 1 or 2.
b3 is preferably 0.
R ⁹ and e1 are the same as described above.

In formula (f1-1-15), a14 is preferably 0 to 3, more preferably 0 to 2, and most preferably 0 or 1.
R ^{51 to} R ⁵² are preferably each independently a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, and are a methyl group, ethyl group, n-propyl group, isopropyl group, n- Butyl group, isobutyl group, tert-butyl group, tert-pentyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, norbornyl group, isobornyl group, tricyclodecanyl group, adamantyl group, tetracyclododecanyl group, etc. Among these, C1-C6 is more preferable, C1-C4 is especially preferable, and a methyl group or an ethyl group is the most preferable.
R ^{53 to} R ⁵⁴ are preferably each independently a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. The linear, branched or cyclic alkyl group having 1 to 10 carbon atoms in R ^{53 to} R ⁵⁴ is the same as R ^{51 to} R ⁵² described above.
In formula (f1-1-16), A ₁ is a cyclic alkylene group having 4 to 20 carbon atoms, preferably a cyclic alkylene group having 5 to 15 carbon atoms, and a cyclic alkylene group having 6 to 12 carbon atoms. More preferred. Specific examples include those exemplified in the “cyclic aliphatic hydrocarbon group” in the hydrocarbon group which may have a substituent as described above, and the cyclic aliphatic hydrocarbon group has a carbon number. It is preferable that it is 3-20, and it is more preferable that it is 3-12.
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.

In formula (f1-1-21), a8 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and most preferably 0 or 1.
a9 is preferably an integer of 1 to 3, and more preferably 1 or 2.
b4 is preferably 0.
R ⁹ and e1 are the same as described above.
In formula (f1-1-22), a10 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and most preferably 0 or 1.
a11 is preferably an integer of 1 to 3, and more preferably 1 or 2.
b5 is preferably 0.
R ⁹ and e1 are the same as described above.
In formula (f1-1-23), a12 is preferably an integer of 1 to 3, and more preferably 1 or 2.
R ⁹ and e1 are the same as described above.
In formula (f1-1-24), a13 is preferably an integer of 1 to 3, and more preferably 1 or 2.
R ⁹ and e1 are the same as described above.

In formulas (f1-1-25) to (f1-1-26), each of a15 and a16 is preferably 0 to 3, more preferably 0 to 2, and most preferably 0 or 1.
R ^{51 to} R ⁵² and R ^{53 to} R ⁵⁴ are the same as described above.
R ⁹ and e1 are the same as described above.

  Specific examples of the structural units represented by the general formulas (f1-1-11) to (f1-1-16) and the general formulas (f1-1-21) to (f1-1-26) are shown below. .

［式中、Ｒ^α’は水素原子またはメチル基を表す。］

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

［式中、Ｒ^α’は水素原子またはメチル基を表す。］

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

［式中、Ｒ^α’は水素原子またはメチル基を表す。］

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

［式中、Ｒ^α’は水素原子またはメチル基を表す。］

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

［式中、Ｒ^α’は水素原子またはメチル基を表す。］

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

  The structural unit (f1-1) is represented by any one of the general formulas (f1-1-11) to (f1-1-16) and (f1-1-21) to (f1-1-26). And at least one selected from the group consisting of the structural units represented by formulas (f1-1-11) to (f1-1-13), (f1-1-21) and (f1-1-22). More preferably, at least one selected from the group consisting of structural units represented by any of the above: a group consisting of structural units represented by the general formulas (f1-1-11) and (f1-1-22) At least one selected from the above is particularly preferable, and the structural unit represented by the general formula (f1-1-11) is most preferable.

In the component (F), the structural unit (f1) can be used alone or in combination of two or more.
The proportion of the structural unit (f1) in the component (F) is preferably 30 to 95 mol%, more preferably 40 to 90 mol%, more preferably 50 to 85 mol% is more preferable.
When the proportion of the structural unit (f1) is equal to or higher than the lower limit of the above range, in the formation of the resist pattern, the characteristics of increasing the hydrophobicity of the resist film are further improved. By setting it to the upper limit value or less, the balance with other structural units becomes good.

  When the structural unit (f1-1) is used as the structural unit (f1), the proportion of the structural unit (f1-1) in the component (F) is based on the total of all the structural units constituting the component (F). 30 to 95 mol% is preferable, 40 to 90 mol% is more preferable, and 50 to 85 mol% is more preferable. By being at least the lower limit of the above range, the property of increasing the hydrophobicity of the resist film is further improved. By setting it to the upper limit value or less, the balance with other structural units becomes good.

-About other structural unit (structural unit (f2)) The component (F) is a structural unit other than the structural unit (f1) (hereinafter referred to as "structural unit (f2)") as long as the effects of the present invention are not impaired. You may have.
The structural unit (f2) is not particularly limited as long as it is a structural unit derived from a compound copolymerizable with the compound that derives the structural unit (f1).
Examples of the structural unit (f2) include those proposed so far as the structural units of the base resin for chemically amplified resists. For example, the structural units (a1) to (a4) in the component (A1) described above. Is mentioned. Especially, when using for a positive type resist composition, a structural unit (a1) is mentioned as a suitable thing.

  In the component (F), the structural unit (f2) can be used alone or in combination of two or more.

For example, when the structural unit (a1) is used as the structural unit (f2), the structural unit represented by the general formula (a1-1) or (a1-3) is preferable among the structural units (a1). The structural unit represented by (a1-1) is more preferable, and is represented by formulas (a1-1-16) to (a1-1-23), formula (a1-1-27), or (a1-1-31). ) To (a1-1-33) are particularly preferable.
The proportion of the structural unit (a1) in the component (F) is preferably 1 to 40 mol%, more preferably 5 to 30 mol%, based on the total of all structural units constituting the component (F).
When the proportion of the structural unit (a1) is in the above range, the water repellency is further improved and the balance with other structural units is improved.

In the resist composition of the present invention, the component (F) is preferably a polymer compound having the structural unit (f1) (hereinafter referred to as “fluorinated resin (F1-1)”).
Examples of such a fluororesin (F1-1) include a copolymer having the structural unit (f1) and the structural unit (f2). Specifically, the structural unit (f1) and the structural unit (a1) are combined. The copolymer which has is mentioned as a suitable thing.
Especially, as a fluorine-containing resin (F1-1), the copolymer which consists of a structural unit (f1-1) and a structural unit (a1) is especially preferable.

In the component (F), the fluorine-containing resin (F1-1) may be used alone or in combination of two or more.
In the resist composition of the present invention, the fluorine-containing resin (F1-1) used in the positive resist composition is particularly preferably one containing the following combination of structural units.

［式中、Ｒは前記と同じであり、複数のＲはそれぞれ同じであっても異なっていてもよい。ｊ”は１〜３の整数であり、１又は２が好ましく、１が最も好ましい。Ｒ^２０は炭素数１〜５の低級アルキル基であり、Ｒにおける低級アルキル基と同様であり、メチル基又はエチル基が特に好ましく、エチル基が最も好ましい。ｈ”は１〜６の整数であり、３又は４が好ましく、４が最も好ましい。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. j ″ is an integer of 1 to 3, preferably 1 or 2, and most preferably 1. R ²⁰ is a lower alkyl group having 1 to 5 carbon atoms, and is the same as the lower alkyl group in R, a methyl group or An ethyl group is particularly preferable, and an ethyl group is most preferable. H ″ is an integer of 1 to 6, preferably 3 or 4, and most preferably 4. ]

The mass average molecular weight (Mw) of the component (F) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 2000 to 50000, more preferably 3000 to 30000, and most preferably 4000 to 25000. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw / Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows a number average molecular weight.

  The component (F) is a monomer for deriving each structural unit constituting the component (F), for example, a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (V-601). It can be obtained by polymerization by the known radical polymerization used.

  It is preferable that the content rate of (F) component in the resist composition of this invention exists in the range of 0.5-30 mass parts with respect to 100 mass parts of below-mentioned (A) component, and 1-20 mass parts is preferable. More preferred is 1 to 10 parts by mass. By setting it to be equal to or higher than the lower limit of the above range, the hydrophobicity of a resist film formed using the resist composition is improved. Also, a hydrophobic resist film suitable for immersion exposure is formed. The solubility to a resist solvent (organic solvent) improves more as it is below an upper limit. In addition, lithography characteristics are improved.

[(E) 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 include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of 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.

[(S) component]
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter 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; many such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol 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 normal method. 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.
According to the resist composition of the present invention, both excellent solubility in a developing solution and good lithography characteristics can be achieved. In particular, since the solubility of the component (B1) in the alkali developer after exposure is high, the risk of reprecipitation of the component (B1) is low, so that a resist pattern with few defects can be formed. The reason why such an effect is obtained is not certain but is presumed as follows.
In the resist composition of the present invention, an acid generator (B1) comprising a compound having a group represented by the general formula (I) in the cation portion is used. In the component (B1), a single bond of O—C in “—O—C (═O) —” of the group represented by the general formula (I) is formed by the action of an alkali developer (alkaline aqueous solution). When cleaved (hydrolyzed), “—C (═O) —CH ₂ —Q ⁵ —R ⁵ ” dissociates from the cation moiety of the component (B1). Then, a compound having a terminal “—OH” and a carboxylic acid “HO—C (═O) —CH ₂ —Q ⁵ —R ⁵ ” are formed. Since the compound and the carboxylic acid are highly soluble in an alkaline developer, the risk of reprecipitation, undissolved residue, re-adhesion, etc. after development of the component (B1) is lower than that of conventional acid generators. Therefore, it is considered that such an effect can be obtained.

In addition, the resist composition of the present invention can form a good resist pattern having a good space part detachability and close to the size of the target space, for example, in line and space resist pattern formation.
The resist composition of the present invention also has good lithography properties such as exposure margin (EL margin). The “EL margin” indicates that the larger the value, the smaller the change amount of the pattern size due to the variation of the exposure amount, and the higher the process margin.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention comprises a step of forming a resist film on a support using the resist composition of the present invention, a step of exposing the resist film, and an alkali developing of the resist film to form a resist pattern Forming a step.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition of the present invention is applied onto a support with a spinner or the like, and prebaked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 150 ° C. under a temperature condition of 80 to 150 ° C. This is applied for 90 seconds, and this is selected by using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus, for example, by exposure through a mask pattern or by direct irradiation of an electron beam without using a mask pattern. After the exposure, PEB (post-exposure heating) is applied for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Next, this is developed with 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, and particularly effective for ArF excimer laser, EB or EUV.

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

≪Compound≫
The compound of the 3rd aspect of this invention is a compound (henceforth "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) can be produced by a conventional method.
As a specific example, for example, when R ⁷ ″ is an aryl group having one group represented by the formula (I), the compound (hereinafter referred to as “compound (b1-1-a)”) It can be manufactured as follows.
First, in a solution of an organic acid H ⁺ B ⁻ (B ⁻ represents an anion portion of an organic acid such as a methanesulfonate ion), a compound represented by the formula (b1-01) and the formula ( b1-02) and a compound represented by the following general formula (b1) from which the organic layer is recovered by adding pure water and an organic solvent (for example, dichloromethane, tetrahydrofuran, etc.). -03) 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.

Next, an organic solvent a compound represented by the formula (b1-05) (e.g., dichloromethane, tetrahydrofuran, etc.) and dissolved in a mixed solvent of water, the desired anion X thereto ^- alkali metal salts of L ⁺ X ^- ( L ⁺ represents, for example, an alkali metal cation such as lithium ion, sodium ion, potassium ion, etc.), reacted, separated, washed with water, and then the compound (b1-1-11-a) is recovered from the organic layer. .

In the formula, R ⁸ ″ to R ⁹ ″, Q ⁵ , R ⁵ and X ⁻ are the same as defined above, Ar is an arylene group, B ⁻ is an anion part of an organic acid, and L ⁺ is an alkali. It is a metal cation, and _Xh is a halogen atom.
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 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.

The compound (b1-11) described above is a novel compound that has not been conventionally known.
Moreover, this compound (b1-11) is a novel compound useful as an acid generator for resist compositions, and can be mix | blended with a resist composition as an acid generator.

≪Acid generator≫
The acid generator which is the 4th aspect of this invention consists of a compound represented by the said general formula (b1-11).
The acid generator is useful as an acid generator for a chemically amplified resist composition, for example, the acid generator component (B) of the resist composition according to the first aspect of the present invention.

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

<Synthesis of base material component (A)>
In this example, the resin component (A1) used as the base material component (A) was synthesized by Synthesis Example 2 shown below using Compound (1) synthesized by Synthesis Example 1 below.

[Synthesis Example 1 (Synthesis of Compound (1))]
In a 500 ml three-necked flask, under a nitrogen atmosphere, 20 g (105.14 mmol) of alcohol (1), 30.23 g (157.71 mmol) of ethyldiisopropylaminocarbodiimide (EDCI) hydrochloride and 0.6 g of dimethylaminopyridine (DMAP) After adding 300 ml of a THF solution of (5 mmol), 16.67 g (115.66 mmol) of the precursor (1) was added under ice cooling (0 ° C.), and the mixture was stirred at room temperature for 12 hours.
After confirming disappearance of the raw material by thin layer chromatography (TLC), 50 ml of water was added to stop the reaction. The reaction solvent was concentrated under reduced pressure, and the organic layer obtained by extraction three times with ethyl acetate was washed with water, saturated sodium bicarbonate and 1N-HClaq in this order. The product obtained by distilling off the solvent under reduced pressure was dried to obtain compound (1).

The instrumental analysis result of the obtained compound (1) was as follows.
¹ H-NMR (CDCl ₃ , 400 MHz): δ (ppm) = 6.22 (s, 1H, H ^a ), 5.70 (s, 1H, H ^b ), 4.71-4.85 (m, 2H, H ^{c, d} ), 4.67 (s, 2H, H ^k ), 3.40-3.60 (m, 2H, H ^{e, f} ), 2.58-2.70 (m, 1H, ^{H g), 2.11-2.21 (m,} 2H, H h), 2.00 (s, 3H, H i), 1.76-2.09 (m, 2H, H j).
From the results described above, it was confirmed that the compound (1) had a structure shown below.

[Synthesis Example 2 (Synthesis of Polymer Compound 1)]
In a three-necked flask connected with a thermometer and a reflux tube, 11.77 g (69.23 mmol) of compound (2), 15.00 g (47.47 mmol) of compound (1), 16.58 g (63.29 mmol) Compound (4), 4.65 g (27.69 mmol) of compound (5), 3.27 g (13.85 mmol) of compound (3) were dissolved in 76.91 g of methyl ethyl ketone (MEK). To this solution, 22.1 mmol of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved. The resultant was dropwise added to 42.72 g of MEK heated to 78 ° C. in a nitrogen atmosphere over 3 hours. After completion of dropping, the reaction solution was heated and stirred for 4 hours, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization solution was dropped into a large amount of normal (n-) heptane, and the polymer was precipitated. The precipitated white powder was filtered, washed with a mixed solvent of n-heptane / isopropyl alcohol, and dried. As a result, 41 g of the target polymer compound 1 was obtained.
For this polymer compound 1, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 7,900, and the molecular weight dispersity (Mw / Mn) was 1.78. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is a2 / a0 / a11 / a12 / a3 = It was 35.0 / 26.5 / 17.9 / 13.2 / 7.4.

<Synthesis of fluorinated compound component (F)>
In this example, the polymer compound (fluorinated resin 1) used as the fluorine-containing compound component (F) was synthesized according to Synthesis Example 3 shown below.

[Synthesis Example 3 (Synthesis of Fluororesin 1)]
To a three-necked flask connected with a thermometer and a reflux tube was added 15.00 g (54.32 mmol) of compound (6), 5.21 g (23.28 mmol) of compound (7), and 114.52 g of THF. Dissolved. To this solution, 4.66 mmol of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved. The reaction solution was heated and stirred at 80 ° C. for 6 hours under a nitrogen atmosphere, and then cooled to room temperature. The obtained reaction polymerization liquid is concentrated under reduced pressure, then dropped into a large amount of n-heptane, and an operation for precipitating the polymer is performed. The precipitated polymer is filtered, washed and dried, and the target fluorine-containing resin is obtained. 5.6 g of 1 was obtained.
About this fluororesin 1, the mass average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) of standard polystyrene conversion were calculated | required by GPC measurement. As a result, the mass average molecular weight (Mw) was 23900, and the molecular weight dispersity (Mw / Mn) was 1.5. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / = 75.6 / 24. .4.

<Synthesis of Acid Generator Component (B)>
(Examples 1 to 23)
In this example, the acid generator used as the acid generator component (B) was synthesized according to the following synthesis examples.

[Example 1: Synthesis example of compound (B1-1)]
(I) Synthesis Example of Compound (8) Methanesulfonic acid (60.75 g) controlled at 20 ° C. or lower, phosphorus oxide (8.53 g), 2,6-dimethylphenol (8.81 g), and diphenyl sulfoxide (12.2 g) was added in small portions. After aging for 30 minutes while controlling the temperature at 15 to 20 ° C., the temperature was raised to 40 ° C. and aging was performed for 2 hours. Then, the reaction liquid was dripped at the pure water (109.35g) cooled to 15 degrees C or less. After completion of the dropwise addition, dichloromethane (54.68 g) was added, and after stirring, the dichloromethane layer was recovered. In a separate container, 20-25 ° C. hexane (386.86 g) was charged, and the dichloromethane layer was added dropwise. After completion of dropping, the mixture was aged at 20 to 25 ° C. for 30 minutes, and then filtered to obtain compound (8) (yield 70.9%).

(Ii) Synthesis Example of Compound (9) Under a nitrogen atmosphere, compound (8) (4.00 g) and dichloromethane (28.0 g) were added to a three-necked flask and stirred, and triethylamine diluted with dichloromethane (4.00 g) was stirred there. (1.31 g) was added dropwise. While maintaining the reaction system at 10 ° C. or lower, acetoxyacetyl chloride (1.63 g) diluted with dichloromethane (8.00 g) was added dropwise over 15 minutes. Then, reaction was performed at room temperature for 3 hours. After completion of the reaction, the dichloromethane phase was washed with dilute hydrochloric acid and water, and then dichloromethane was distilled off under reduced pressure. The obtained oily substance was dried to obtain 2.76 g of Compound (9).

Compound (9) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.77-7.89 (m, 10H, ArH), 7.70 (s, 2H, ArH), 5.10 (s, 2H) , OCOCH2O), 2.31 (s, 3H, CH3SO3), 2.07-2.19 (m, 9H, OCOCH3 + CH3)
From the results shown above, it was confirmed that the compound (9) had a structure shown below.

(Iii) Synthesis Example of Compound (B1-1) Compound (9) (1.23 g) was completely dissolved in dichloromethane (9.08 g). Thereto were added pure water (3.43 g) and potassium nonafluorobutanesulfonate (1.31 g), and the mixture was stirred at room temperature for 1 hour. After completion of the reaction, washing with water was performed, dichloromethane was distilled off under reduced pressure, and the resulting oily substance was dried to obtain compound (B1-1) (1.55 g).

The compound (B1-1) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.77-7.89 (m, 10H, ArH), 7.70 (s, 2H, ArH), 5.10 (s, 2H) , OCOCH2O), 2.07-2.19 (m, 9H, OCOCH3 + CH3)
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 77.8, −111.9, −118.4, −122.8
From the results shown above, it was confirmed that the compound (B1-1) had a structure shown below.

[Example 2: Synthesis example of compound (B1-6)]
Compound (9) (1.5 g) was completely dissolved in dichloromethane (11.8 g). Pure water (4.44 g) and compound (B1-60) (2.16 g) were added thereto, and the mixture was stirred at room temperature for 1 hour. After completion of the reaction, washing with water was performed, dichloromethane was distilled off under reduced pressure, and the resulting white solid was dried to obtain compound (B1-6) (1.85 g).

The compound (B1-6) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.77-7.89 (m, 10H, ArH), 7.70 (s, 2H, ArH), 5.10 (s, 2H) , OCOCH2O), 4.00-4.26 (m, 4H, CH2), 2.15-2.22 (m, 9H, OCOCH3 + CH3), 1.63-1.98 (m, 15H, Admantane)
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.6
From the results above, it was confirmed that the compound (B1-6) had a structure shown below.

[Examples 3 to 20]
The same operation as in Example 1 (iii) 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). . Thereby, the product (compound (B1-2)-(B1-5), (B1-7-1), (B1-8), (B1-10) which consists of an anion and a cation shown in Tables 1-5) , (B1-12) to (B1-22)) were obtained.
Each compound was analyzed by NMR, and the results are shown in Tables 1 to 5. In Tables 1 to 5, “↑” indicates that the cation of the product is the same as the cation in the cation part of the compound (B1-1).

[Examples 21 to 23]
The same operation as in Example 2 was conducted except that the compound (M ⁺ -X ⁻ ) was synthesized by changing it to those shown in Table 6 below (equal molar amount). This obtained the product (compound (B1-7-2), (B1-9), (B1-11)) which consists of an anion and a cation shown in Table 6.
Each compound was analyzed by NMR, and the results are shown in Table 6. In Table 6, “↑” indicates that the cation of the product is the same as the cation in the cation part of the compound (B1-6).

<Evaluation of degradability for alkali developer>
About the compound (B1-1)-(B1-22) obtained in the Example mentioned above, the decomposability | degradability with respect to an alkali developing solution was evaluated.
Such evaluation is carried out by dissolving 0.1 g of the compound in 0.9 g of an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 23 ° C. and analyzing the solution using liquid chromatography. It was.
As a result, it was confirmed that all of the compounds (B1-1) to (B1-22) were decomposed to generate carboxylic acids and phenols.

<Preparation of resist composition>
[Examples 24-26, Comparative Example 1, Reference Examples 1-2]
The components shown in Table 7 below were mixed and dissolved to prepare a positive resist composition.

In Table 7, each abbreviation indicates the following, and the numerical value in [] is the blending amount (part by mass). “-” Indicates that it is not blended.
(A) -1: The polymer compound 1 described above.
(A) -2: polymer compound 2 (Mw10000, Mw / Mn2.0) represented by the following chemical formula. In addition, l, m, and n in the following chemical formula indicate the ratio (molar ratio) of each structural unit constituting the polymer compound 2.

  (B) -1: Compound (B2-1) represented by the following chemical formula.

(B) -2: Compound (B1-1) above.
(B) -3: Compound (B1-7-1) above.
(B) -4: (4-methylphenyl) diphenylsulfonium nonafluorobutanesulfonate (D) -1: stearyl diethanolamine.
(D) -2: tri-n-pentylamine.
(F) -1: The fluororesin 1 described above.
(S) -1: PGMEA / PGME = 6/4 (mass ratio) mixed solvent.

<Evaluation of lithography characteristics-1>
Using the obtained resist compositions (Reference Examples 1 and 2 and Examples 24 and 25), a resist pattern was formed by the following procedure, and the lithography characteristics were evaluated.
[Resist pattern formation]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a film thickness of 89 nm was formed. Then, each of the obtained resist compositions is applied onto the antireflection film using a spinner, and prebaked (PAB) for 60 seconds at a temperature shown in Table 8 on a hot plate and dried. Thus, a resist film having a thickness of 120 nm was formed.
Next, the resist film is masked (6%) using an ArF immersion exposure apparatus NSR-S609B (Nikon Corporation; NA (numerical aperture) = 1.07, Cross-pole = 0.78 / 0.97). The resist film was selectively irradiated with an ArF excimer laser (193 nm) through a (halftone) pattern.
Subsequently, a post-exposure heating (PEB) treatment for 60 seconds was performed at the temperature shown in Table 8, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, Tokyo (Oka Kogyo Co., Ltd.) was subjected to alkali development for 10 seconds, then rinsed with pure water for 30 seconds, and then shaken and dried. Thereafter, heat treatment was further performed at 100 ° C. for 60 seconds.
As a result, in any of the examples, an island-like line-and-space resist pattern (hereinafter referred to as “LS pattern”) having a space width of 50 nm and a pitch of 100 nm was formed on the resist film.

[sensitivity]
In the above resist pattern formation, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming an LS pattern having a space width of 50 nm and a pitch of 100 nm was determined. The results are shown in Table 8.

[Evaluation of detachability after development (development solubility)]
An LS pattern was formed with a space width of 50 nm and a pitch of 100 nm as targets, the LS pattern was observed with a length measurement SEM, and the size (nm) of the space portion was measured.
The closer the dimension of the space portion is to 50 nm, the better the release property (development solubility) after development. The results are shown in Table 8.

From the results of Table 8, the resist compositions of Examples 24 and 25 have a space portion size close to 50 nm as compared with the resist compositions of Reference Examples 1 and 2, and therefore, the removal property after development (development solubility). It was confirmed that the occurrence of defects (residues) was suppressed.
Further, from the results of this evaluation, compounds (B1-2) to (B1-6), (B1−) other than the compounds (B1-1) and (B1-7) used as the acid generator in Examples 24 and 25 were used. With regard to 8) to (B1-22), the same effects as those of the compounds (B1-1) and (B1-7) can be expected by using them as acid generators.

<Evaluation of lithography characteristics-2>
Using the obtained resist composition (Comparative Example 1, Example 26), a resist pattern was formed by the following procedure, and the lithography characteristics were evaluated.
[Resist pattern formation]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked at 205 ° C. for 60 seconds on a hot plate and dried. Thus, an organic antireflection film having a film thickness of 82 nm was formed. Then, each of the obtained resist compositions is applied onto the antireflection film using a spinner, subjected to a pre-bake (PAB) treatment for 60 seconds at a temperature shown in Table 9 on a hot plate, and dried. Thus, a resist film having a thickness of 120 nm was formed.
Next, the resist film is subjected to an ArF exposure apparatus NSR-602 (manufactured by Nikon; NA (numerical aperture) = 0.60, Annual 2/3) through a mask (6% halftone) pattern through the resist. The film was selectively irradiated with an ArF excimer laser (193 nm).
Subsequently, a post-exposure heating (PEB) treatment for 60 seconds was performed at the temperatures shown in Table 9, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, Tokyo, Japan) at 23 ° C. (Oka Kogyo Co., Ltd.) was subjected to an alkali development treatment for 30 seconds, and then rinsed with pure water for 30 seconds and then shaken and dried.
As a result, in each example, an island-like LS pattern having a space width of 120 nm and a pitch of 240 nm was formed on the resist film.

[sensitivity]
In the above resist pattern formation, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming an LS pattern having a space width of 120 nm and a pitch of 240 nm was determined. The results are shown in Table 9.

[Evaluation of cross-sectional shape of LWR (Line Width Roughness) and LS pattern]
In the LS pattern having a line width of 120 nm and a pitch of 240 nm formed by the Eop, the line width was measured by a length measurement SEM (scanning electron microscope, acceleration voltage 800 V, product name: S-9220, manufactured by Hitachi, Ltd.). Five points were measured in the longitudinal direction, and from the result, a value (3s) that was three times the standard deviation (s) was calculated as a scale indicating LWR. The results are shown in Table 9. The smaller the value of 3s, the smaller the roughness of the line width, which means that a more uniform width LS pattern was obtained.
Moreover, the cross-sectional shape of the LS pattern was observed by SEM. The results are shown in Table 9.

  From the results of Table 9, it was confirmed that the resist composition of Example 26 can form a resist pattern having a better shape than the resist composition of Comparative Example 1.

Claims (3)

The compound represented by the following general formula (b1-11).

Wherein ^(b1-11), one of R 7 "~R ^9" is selected from the group consisting of groups respectively represented by the following general formula (I-1) ~ (I -11) It is a phenyl group having a substituent (however, it may have an alkyl group having 1 to 5 carbon atoms as another substituent), and the remaining two are each a phenyl group . X ⁻ is an anion. ]

[In formulas (I-1) to (I-11), * represents a bond. In formula (I-5), q represents an integer of 1 to 3. ] The compound according to claim 1, wherein X ^- is an anion selected from the group consisting of a sulfonate anion, an imide anion, a methide anion, and a halogen anion.   An acid generator comprising the compound according to claim 1 or 2.