JP2011118123A - Positive resist composition and method for forming resist pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition excellent in depth of focus (DOF) characteristics. <P>SOLUTION: The positive resist composition contains a base component (A) and a photoacid generator component (B). The component (A) contains a resin component (A1) having a structural unit (a0) expressed by general formula (a0-1) and a structural unit (a1) derived from an acrylate containing an acid dissociable dissolution inhibiting group. The component (B) contains an acid generator (B1) and an acid generator (B2) generating a weak acid. In general formula (a0-1), R represents a hydrogen atom, a 1-5C alkyl group or a 1-5C halogenated alkyl group; and W represents a cyclic alkylene group which may include an oxygen atom in any optinal position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

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 rapidly progressed due to advances in lithography technology. As a technique for miniaturization, the exposure light source is generally shortened in wavelength (increased energy). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. Further, studies have been made on EB (electron beam), EUV (extreme ultraviolet), X-rays, and the like having shorter wavelengths (higher energy) than these excimer lasers.

Along with the shortening of the wavelength of the exposure light source, the resist material is required to be improved in lithography characteristics such as sensitivity to the exposure light source and resolution capable of reproducing a pattern with a fine dimension. A chemically amplified resist is known as a resist material that satisfies such requirements. As the chemically amplified resist, a composition containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator component that generates an acid upon exposure is generally used. For example, in the case of a positive-type chemically amplified resist composition, a substrate component that has increased solubility in a base-component alkaline developer by the action of an acid is used.
Conventionally, a resin (base resin) is mainly used as a base component of a chemically amplified resist composition. In the case of the positive type, a resin whose solubility in an alkaline developer is increased by the action of an acid is generally used as the base resin.
At present, as a base resin of a chemically amplified resist composition used in ArF excimer laser lithography and the like, it has a structural unit derived from (meth) acrylic acid ester in its main chain because of its excellent transparency near 193 nm. Resin (acrylic resin) is the mainstream (see, for example, Patent Document 1).

  Here, “(meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position. “(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.

The base resin generally contains a plurality of structural units in order to improve lithography properties and the like. For example, in the case of a positive type, in addition to a structural unit having an acid dissociable, dissolution inhibiting group that is dissociated by the action of an acid generated from an acid generator, a structural unit having a polar group such as a hydroxyl group, or a structure having a lactone structure Those including units are used. In particular, a structural unit having a polar group is widely used because it increases the affinity with an alkali developer and contributes to an improvement in resolution.
Currently, in addition to the base component and acid generator, nitrogen-containing low molecular weight compounds such as alkylamines and alkylalcoholamines are blended into the chemically amplified resist composition (for example, Patent Documents 2 to 2). 3).
Also, it has been proposed to blend a resin containing a nitrogen-containing substituent into a resist composition (see, for example, Patent Document 4).
These nitrogen-containing components act as a quencher that traps the acid generated from the acid generator, and contribute to the improvement of lithography properties such as the resist pattern shape.

JP 2003-241385 A Japanese Patent Laid-Open No. 5-249662 JP-A-5-232706 Japanese Patent Laid-Open No. 11-084660

As the pattern becomes increasingly finer, resist materials are also required to have various lithographic properties or improved pattern shapes as well as high resolution. As lithography characteristics, for example, in order to improve a process margin at the time of pattern formation, an improvement in depth of focus (DOF) characteristics is required.
However, in the conventional resist composition, for example, when trying to form a hole pattern, there is a problem that it is difficult to achieve both the DOF characteristic and the pattern shape, for example, when the DOF characteristic is improved, the roundness is lowered. is there.
The present invention has been made in view of the above circumstances, and has a positive resist composition excellent in depth of focus (DOF) characteristics and capable of forming a pattern having a good shape, and the positive resist composition. It is an object of the present invention to provide a resist pattern forming method used.

As a result of intensive studies, the inventors have used an acid generator having a specific anion moiety, combined with a specific resin containing —OSO ₂ NH ₂ as a polar group, and by exposure. It has been found that the above-mentioned problems can be solved by further using an acid generator that generates an acid having low strength, and the present invention has been completed.
That is, the first aspect of the present invention is a positive containing a base component (A) whose solubility in an alkaline developer is increased by the action of an acid and an acid generator component (B) that generates an acid upon exposure. The base material component (A) is derived from a structural unit (a0) represented by the following general formula (a0-1) and an acrylate ester containing an acid dissociable, dissolution inhibiting group. A resin component (A1) having a structural unit (a1), wherein the acid generator component (B) is selected from the group consisting of compounds represented by any one of the following general formulas (1) to (3). A positive resist composition comprising at least one acid generator (B1) selected and an acid generator (B2) comprising a compound represented by the following general formula (4).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を表し；Ｗは任意の位置に酸素原子を含んでいてもよい環状のアルキレン基を表す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; W represents a cyclic alkylene group which may contain an oxygen atom at an arbitrary position; To express. ]

［式中、Ｘ^１０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、Ｑ^１はカルボニル基を含む２価の連結基であり、ｐは１〜３の整数であり；Ｘ^２０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、Ｑ^２は単結合またはアルキレン基であり、ｑは１〜３の整数であり；Ｘ^３０は置換基を有していてもよい炭素数１〜３０の炭化水素基であり、Ｑ^３は単結合または２価の連結基であり、Ｙ^１０はカルボニル基またはスルホニル基であり、Ｙ^１１は置換基を有していてもよい炭素数１〜１０のアルキル基または置換基を有していてもよい炭素数１〜１０のフッ素化アルキル基であり；Ａ^＋は対カチオンである。］

[Wherein, X ¹⁰ is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ¹ is a divalent linking group containing a carbonyl group, and p is an integer of 1 to 3. by ^{and; X 20} represents a hydrocarbon group having 3 to 30 carbon atoms which may have a substituent group, ^{Q 2} is a single bond or an alkylene group, q is an integer from 1 to ^{3; X 30} Is an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, Q ³ is a single bond or a divalent linking group, Y ¹⁰ is a carbonyl group or a sulfonyl group, and Y ¹¹ is An alkyl group having 1 to 10 carbon atoms which may have a substituent or a fluorinated alkyl group having 1 to 10 carbon atoms which may have a substituent; A ⁺ is a counter cation. ]

［式（４）中、Ｒ^０は置換基を有していてもよい炭素数１〜１２の炭化水素基である。ただし、−ＳＯ_３ ⁻における硫黄原子に隣接する炭素原子にはフッ素原子は結合していない。Ａｂ^＋は芳香族基を有する対カチオンである。］

[In Formula (4), ^R0 is a C1-C12 hydrocarbon group which may have a substituent. However, the fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in —SO ₃ ^— . Ab ⁺ is a counter cation having an aromatic group. ]

  According to a second aspect of the present invention, there is provided a step of forming a resist film on a support using the positive resist composition of the first aspect, a step of exposing the resist film, and an alkali development of the resist film. And a resist pattern forming method including a step of forming a resist pattern.

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, and the like that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms, and the “halogenated alkylene group” is a part of or all of the hydrogen atoms in the alkylene group is a halogen atom. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The “hydroxyalkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a hydroxyl group.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

  ADVANTAGE OF THE INVENTION According to this invention, the resist pattern formation method using the positive resist composition which is excellent in a depth of focus width (DOF) characteristic, and can form a pattern of a favorable shape, and this positive resist composition can be provided.

6 is a graph showing a result of “a film reduction amount with respect to an exposure amount” when using a resin solution A in Test Example 1; 6 is a graph showing a result of “a film reduction amount with respect to an exposure amount” when using a resin solution A ′ in Test Example 1. FIG.

≪Positive resist composition≫
The positive resist composition of the present invention comprises a base component (A) (hereinafter referred to as component (A)) whose solubility in an alkaline developer is increased by the action of an acid, and an acid generator that generates an acid upon exposure. Component (B) (hereinafter referred to as component (B)).
In such a positive resist composition, when radiation is irradiated (exposed), an acid is generated from the component (B), and the solubility of the component (A) in an alkaline developer is increased by the action of the acid. Therefore, in the formation of the resist pattern, when selective exposure is performed on the resist film obtained using the positive resist composition, the solubility of the exposed portion of the resist film in the alkaline developer increases. Since the solubility of the unexposed portion in the alkaline developer does not change, a resist pattern can be formed by performing alkali development.

<(A) component>
In the present invention, the “base material component” means an organic compound having a film forming ability.
As the base material component, an organic compound having a molecular weight of 500 or more is usually used. When the molecular weight is 500 or more, it has a sufficient film forming ability and can easily form a nano-level resist pattern.
“Organic compounds having a molecular weight of 500 or more” are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the term “low molecular compound” refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, those having a molecular weight of 1000 or more are usually used. In the present specification and claims, “polymer compound” refers to a polymer having a molecular weight of 1000 or more.
In the case of a polymer compound, the “molecular weight” is a polystyrene-reduced mass average molecular weight determined by GPC (gel permeation chromatography).

  In the positive resist composition of the present invention, the component (A) is derived from the structural unit (a0) represented by the general formula (a0-1) and an acrylate ester containing an acid dissociable, dissolution inhibiting group. A resin component (A1) having a structural unit (a1) (hereinafter referred to as component (A1)) is contained.

[Resin component (A1)]
The component (A1) has the structural unit (a0) and the structural unit (a1).
In addition to the structural units (a0) and (a1), the component (A1) further includes a structural unit derived from an acrylate ester containing a —SO ₂ — containing cyclic group and an acrylic acid containing a lactone-containing cyclic group It is preferable to have at least one structural unit (a2) selected from the group consisting of structural units derived from esters.
In addition to the structural units (a0) and (a1), or in addition to the structural units (a0), (a1) and (a2), the component (A1) is an acrylic containing a polar group-containing aliphatic hydrocarbon group You may have the structural unit (a3) induced | guided | derived from an acid ester.
The component (A1) is added to the structural units (a0), (a1) and (a1), or in addition to the structural units (a0), (a1) and (a2), or the structural units (a0), (a1) and (a3). ) Or in addition to the structural units (a0), (a1), (a2) and (a3), and a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic cyclic group (A4) may be included.

(Structural unit (a0))
The structural unit (a0) is represented by the general formula (a0-1).
In formula (a0-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl. Group, pentyl group, isopentyl group, neopentyl group and the like.
The fluorinated alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched fluorinated alkyl group, such as a monofluoromethyl group, difluoromethyl group, trifluoromethyl group, perfluoroethyl group. Perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoroisobutyl group, perfluoro-tert-butyl group, perfluoropentyl group, perfluoroisopentyl group, perfluoroneopentyl group and the like.
R is preferably a hydrogen atom, a methyl group or a trifluoromethyl group, more preferably a hydrogen atom or a methyl group, from the viewpoint of industrial availability.

In formula (a0-1), W represents a cyclic alkylene group which may contain an oxygen atom at an arbitrary position.
The alkylene group preferably has 3 to 20 carbon atoms, and more preferably 5 to 12 carbon atoms.
The alkylene group is preferably both monocyclic and polycyclic because it is excellent in various lithography properties. From the viewpoint that the lithography properties are improved by increasing Tg and the etching resistance is further improved, polycyclic is preferable, and 2 to 4 cyclic is preferable.
Specific examples of the alkylene group include a cyclopropanediyl group, a cyclobuta-1,2-diyl group, a cyclobuta-1,3-diyl group, a cyclopenta-1,2-diyl group, and a cyclopenta-1,3-diyl. Group, cyclohexa-1,2-diyl group, cyclohexa-1,3-diyl group, cyclohexa-1,4-diyl group, bicyclo [2.2.1] hepta-2,3-diyl group, bicyclo [2. 2.1] hepta-2,5-diyl group, 7-oxabicyclo [2.2.1] hepta-2,5-diyl group, bicyclo [2.2.1] hepta-2,6-diyl group, Examples include 7-oxabicyclo [2.2.1] hepta-2,6-diyl group, adamanta-1,3-diyl group, adamanta-1,2-diyl group and the like.

  More specifically, examples of the structural unit (a0) include structural units represented by the following formulas (a0-1-10) to (a0-1-33).

In the component (A1), as the structural unit (a0), one type of structural unit may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a0) is preferably 1 to 40 mol%, more preferably 1 to 35 mol%, and more preferably 5 to 30 mol% with respect to all the structural units constituting the component (A1). Is more preferable, and 5 to 25 mol% is particularly preferable. Lithographic properties such as DOF are improved by setting it to the lower limit value or more, and balancing with other structural units can be achieved by setting the upper limit value or less.

(Structural unit (a1))
The structural unit (a1) is a structural unit derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
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 bonded to the α-position carbon atom include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
In the acrylic ester, the alkyl group having 1 to 5 carbon atoms as the substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl C1-C5 linear or branched alkyl groups, such as a group, a pentyl group, an isopentyl group, and a neopentyl group.
As the halogenated alkyl group having 1 to 5 carbon atoms as the substituent at the α-position, specifically, a part or all of the hydrogen atoms of the above “alkyl group having 1 to 5 carbon atoms as the substituent at the α-position” Is a group substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
The α-position of the acrylate ester is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Are more preferably an alkyl group or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group in terms of industrial availability.

The “acid-dissociable, dissolution-inhibiting group” is dissociated before the dissociation by the action of an acid that is generated from the component (B) upon exposure and the alkali dissolution-inhibiting property that makes the entire component (A1) difficult to dissolve in an alkali developer. It is a group having acid dissociation properties. When the acid dissociable, dissolution inhibiting group in the structural unit (a1) is dissociated, the solubility of the entire component (A1) in the alkali developer increases.
As the acid dissociable, dissolution inhibiting group in the structural unit (a1), those proposed so far as the acid dissociable, dissolution inhibiting group of the base resin for chemically amplified resist can be used. Generally, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. . 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.
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 without 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 “acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group” may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like. Is mentioned.
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 may be monocyclic or polycyclic.
Examples of the aliphatic cyclic group include one or more hydrogens from a monocycloalkane which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group. Examples thereof include a group 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 an alicyclic hydrocarbon group such as a group in which a hydrogen atom is removed. Moreover, a part of carbon atoms constituting the ring of these alicyclic hydrocarbon groups may be substituted with an ether group (—O—).

Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include:
(I) Substitution with a carbon atom bonded to an atom adjacent to the acid dissociable, dissolution inhibiting group (for example, —O— in —C (═O) —O—) on the ring skeleton of a monovalent aliphatic cyclic group A group in which a group (atom or group other than a hydrogen atom) is bonded to form a tertiary carbon atom;
(Ii) a group having a monovalent aliphatic cyclic group and a branched alkylene having a tertiary carbon atom bonded thereto; and the like.
In the group (i), examples of the substituent bonded to the carbon atom bonded to the atom adjacent to the acid dissociable, dissolution inhibiting group on the ring skeleton of the aliphatic cyclic group include an alkyl group. Examples of the alkyl group include those similar to R ¹⁴ in formulas (1-1) to (1-9) described later.
Specific examples of the group (i) include groups represented by the following general formulas (1-1) to (1-9).
Specific examples of the group (ii) include groups represented by the following general formulas (2-1) to (2-6).

［式中、Ｒ^１４はアルキル基であり、ｇは０〜８の整数である。］

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

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立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.
g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and still 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 an alkyl group having 1 to 5 carbon atoms, 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炭素数１〜５のアルキル基を表し、ｎは０〜３の整数を表し、Ｙは炭素数１〜５の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 an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl group having 1 to 5 carbon atoms. Or represents an aliphatic cyclic group. ]

In formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group for R ¹ ′ and R ² ′ include the same alkyl groups as those described above for the α-position substituent in the description of the acrylic ester, and a methyl group or an ethyl group is preferable. Is most preferred.
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 alkyl group for Y include the same alkyl groups as those described as the α-position substituent in the description of the acrylic ester.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups conventionally proposed in a number of ArF resists and the like. For example, the above “aliphatic ring” Examples thereof are the same as the aliphatic cyclic groups mentioned in “Acid-dissociable, dissolution-inhibiting group containing a 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 above formula ^(p2), a ^{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 terminal of ^{R 19} 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.

  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、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；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, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X ¹ is an acid dissociable, dissolution inhibiting group; Y ² is a divalent linkage. X ² is an acid dissociable, dissolution inhibiting group. ]

In general formula (a1-0-1), the alkyl group and halogenated alkyl group represented by R are the same as the alkyl group and halogenated alkyl group mentioned as the substituent at the α-position in the description of the acrylate ester, respectively. Can be mentioned. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group.
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 of Y ^2, but are not limited to, divalent hydrocarbon group which may have a substituent group, and a divalent linking group containing a hetero atom as preferred.
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 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 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 hydrocarbon group, a branched alkylene group is preferable, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —. _{, -C (CH 3) (CH} 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - and the like alkyl methylene groups; -CH ( _{CH 3) CH 2 -, -} CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 3 Alkylalkylene groups such as CH ₂ —, —C (CH ₂ CH ₃ ) ₂ CH ₂ —, etc .; alkyltri groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —, etc. _{methylene; -CH (CH 3) CH 2} CH 2 CH 2 -, - CH 2 CH CH _{3) CH} 2 CH ₂ - alkyl alkylene group such as an alkyl tetramethylene group such like. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), Examples thereof include a group bonded to the end of the aliphatic hydrocarbon group or interposed in the middle of the chain-like aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms are removed from a C 3-6 monocycloalkane is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon 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, tetracyclododecane and the like.
The alicyclic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

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 of 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 a part of carbon atoms constituting the ring is substituted with the heteroatom.
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, and an oxygen atom (═O).
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.

The hetero atom in the “divalent linking group containing a hetero atom” is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
As the divalent linking group containing a hetero atom, specifically, —O—, —C (═O) —, —C (═O) —O—, carbonate bond (—O—C (═O) — _{O -), - S -,} - S (= O) 2 -, - S (= O) 2 -O -, - NH -, - NR 04 (R 04 is an alkyl group, a substituent such as an acyl group .)-, -NH-C (= O)-, = N- and the like, and combinations of at least one of these non-hydrocarbon groups with a divalent hydrocarbon group. Examples of the divalent hydrocarbon group include the same divalent hydrocarbon groups that may have a substituent as described above, and a linear or branched aliphatic hydrocarbon group is preferable. .

The divalent linking group for Y ² is preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom. Among these, a linear or branched alkylene group or a divalent linking group containing a hetero atom is preferable.
When Y 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 Y ² is a divalent alicyclic hydrocarbon group, examples of the alicyclic hydrocarbon group include the alicyclic hydrocarbon groups listed in the above-mentioned “aliphatic hydrocarbon group containing a ring in the structure”. The same thing is mentioned.
The alicyclic hydrocarbon group is particularly preferably a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane or tetracyclododecane.

When Y ² is a divalent linking group containing a hetero atom, 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—, general formula —A—O—B—, — [A—C (═O) —O] _{m ′} —B— or —A—O—. A group represented by C (═O) —B—, wherein A and B are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, m 'is an integer of 0-3. ] Etc. are mentioned.
When Y ² is —NH—, H may be substituted with a substituent such as an alkyl group or an aryl group (aromatic group). The substituent (alkyl group, aryl 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 formulas -A-O-B-,-[A-C (= O) -O] _{m '} -B- or -A-O-C (= O) -B-, A and B are each independently And a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same groups as those described above as the “divalent hydrocarbon group which may have a substituent” for Y ² .
As A, a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group or an ethylene group is particularly preferable. .
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 — [AC (═O) —O] _{m ′} —B—, m ′ is an integer of 0 to 3, preferably an integer of 0 to 2, 0 or 1 Is more preferable, and 1 is most preferable.
As the divalent linking group containing a hetero atom, a linear group having an oxygen atom as a hetero atom, for example, a group containing an ether bond or an ester bond, is preferred, and the above formulas -A-O-B-,-[A —C (═O) —O] is more preferably a group represented by _{m ′} —B— or —A—O—C (═O) —B—.
Among these, the formula -A-O-B- or - [A-C (= O ) -O] m ' group is preferably represented by -B-, wherein - [A-C (= O ) - O] A group represented by _{m ′} —B— is more preferable, and m ′ in the formula is more preferably 1, and — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) b _'- is particularly desirable.
a ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1.
b ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1.

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

［式中、Ｒ、Ｒ^１’、Ｒ^２’、ｎ、ＹおよびＹ^２はそれぞれ前記と同じであり、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す。］’

[Wherein, R, R ¹ ′, R ² ′, n, Y and Y ² are the same as defined above, and X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group. ] '

In the formula, X ′ is the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group.
^{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.

  In the present invention, as the structural unit (a1), a structural unit represented by the following general formula (a1-0-11), a structural unit represented by the following general formula (a1-0-12), and the following general formula ( It preferably has at least one selected from the group consisting of a structural unit represented by a1-0-13) and a structural unit represented by the following general formula (a1-0-2). Among these, a structural unit represented by the formula (a1-0-11), a structural unit represented by the following general formula (a1-0-12), and a structure represented by the following general formula (a1-0-2) It is preferable to have at least one selected from the group consisting of units.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、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、Ｒ^２５は炭素数１〜５の直鎖状のアルキル基である。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, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ²¹ is an alkyl group, and R ²² is a carbon to which R ²² is bonded. A group that forms an aliphatic monocyclic group together with an atom; R ²³ is a branched alkyl group; and R ²⁴ is a group that forms an aliphatic polycyclic group together with the carbon atom to which R ²⁴ is bonded. R ²⁵ is a linear alkyl group having 1 to 5 carbon atoms. Y ² is a divalent linking group, and 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 or isopropyl group is 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 ether group (—O—).
Moreover, this monocycloalkane may have a C1-C5 alkyl group, a fluorine atom, or a C1-C5 fluorinated alkyl group as a substituent.
Examples of R ²² constituting the aliphatic monocyclic group include a linear alkylene group in which an ether group (—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), (a1-1-27), and (a1-1 -31). Among these, the formulas (a1-1-16) to (a1-1-17), (a1-1-20) to (a1-1-23), (a1-1-27), (a1-1-1- The structural unit represented by the following (a1-1-02) including the structural unit represented by 31) 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.

［式中、Ｒ、Ｒ^２１はそれぞれ前記と同じであり、ｈは１〜３の整数である。］

[Wherein, R and R ²¹ are the same as defined above, and h is an integer of 1 to 3, respectively. ]

In the formula (a1-0-12), the branched alkyl group represented by R ^{23 is} the branched alkyl group exemplified for the alkyl group represented by R ^{14 in} the formulas (1-1) to (1-9). 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 those represented by the formulas (a1-1-26) and (a1-1-28) to (a1-1-30). Units are listed.
The constitutional unit represented by formula ^{(a1-0-12), R 24} is preferably the aliphatic polycyclic group which forms together with the carbon atom to which ^{R 24} is bonded is a 2-adamantyl group, especially The structural unit represented by the formula (a1-1-26) is preferable.

In formula (a1-0-13), R and R ²⁴ are the same as defined above.
Examples of the linear alkyl group for R ²⁵ include the same linear alkyl groups as those described above for the alkyl group for R ¹⁴ in formulas (1-1) to (1-9), and methyl Most preferred are groups or ethyl groups.
Specific examples of the structural unit represented by formula (a1-0-13) include formulas (a1-1-1) to (a1-1-2) exemplified as specific examples of general formula (a1-1). ), Structural units represented by (a1-1-7) to (a1-1-15).
The constitutional unit represented by formula ^{(a1-0-13), R 24} is preferably the aliphatic polycyclic group which forms together with the carbon atom to which ^{R 24} is bonded is a 2-adamantyl group, especially The structural unit represented by the formula (a1-1-1) or (a1-1-2) is preferable.

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), particularly represented by the formula (a1-3). Are preferred.
As the structural unit represented by the formula (a1-0-2), particularly, Y ^{2 in} the formula is represented by the above-mentioned —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は前記と同じであり、Ｒ^１３は水素原子またはメチル基であり、Ｒ^１４はアルキル基であり、ｙは１〜１０の整数であり、ｎ’は０〜３の整数である。］

[Wherein, R is as defined above, R ¹³ is a hydrogen atom or a methyl group, R ¹⁴ is an alkyl group, y is an integer of 1 to 10, and n ′ is an integer of 0 to 3] is there. ]

［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、ｗは０〜３の整数である。］

[Wherein, R is the same as defined above, Y ² ′ and Y ² ″ are each independently a divalent linking group, X ′ is an acid dissociable, dissolution inhibiting group, and w is 0-3. It is an integer.]

In formulas (a1-3-01) to (a1-3-02), R ¹³ is preferably a hydrogen atom.
R ¹⁴ is the same as ^{R 14} in the formula (1-1) to (1-9).
y 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 still 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 for 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 in which a substituent is bonded to a carbon atom bonded to an atom adjacent to the acid dissociable, dissolution inhibiting group on the ring skeleton of the group to form a tertiary carbon atom is more preferable. The group represented by 1-1) is preferable.
w is an integer of 0 to 3, and w is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.
The structural unit represented by the formula (a1-3-03) is preferably a structural unit represented by the following general formula (a1-3-03-1) or (a1-3-03-2), The structural unit represented by the formula (a1-3-03-1) is 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. ]

In formulas (a1-3-03-1) to (a1-3-03-2), a ′ is preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and particularly preferably 1 or 2.
b ′ is preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and particularly preferably 1 or 2.
t is preferably an integer of 1 to 3, and 1 or 2 is particularly preferable.
Specific examples of the structural unit represented by formula (a1-3-03-1) or (a1-3-03-2) include those represented by formulas (a1-3-29) to (a1-3-32). The structural unit represented is mentioned.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
In particular, it is preferable to have at least two structural units (a1) because the lithography properties are improved. When the component (A1) has at least two structural units (a1), the number of the structural units (a1) is preferably 2 to 4, more preferably 2 or 3.
Further, 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), or the general A structural unit selected from the group consisting of a structural unit represented by formula (a1-0-13) and a structural unit represented by formula (a1-0-2) is preferred.
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), It may be composed only of those selected from the group consisting of the structural unit represented by general formula (a1-0-13) and the structural unit represented by general formula (a1-0-2). A combination of at least one of the structural units and another structural unit (a1) not corresponding to these structural units may be used.
Examples of the other structural unit (a1) include a structural unit represented by the general formula (a1-2), a structural unit represented by the general formula (a1-4), and the like.

  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 composed of a structural unit derived from an acrylate ester containing a —SO ₂ -containing cyclic group (hereinafter referred to as a structural unit (a2 ^S )) and an acrylate ester containing a lactone-containing cyclic group. It is at least one kind of structural unit selected from the group consisting of derived structural units (hereinafter referred to as structural units (a2 ^L )).
The structural unit (a2) contains a —SO ₂ — containing cyclic group or a lactone cyclic group, whereby a resist film formed using the positive resist composition containing the component (A1) is applied to the substrate. It contributes to the improvement of lithography properties by increasing the adhesion or increasing the affinity with a developer containing water.

-Structural unit (a2 ^S ):
The structural unit (a2 ^S ) is a structural unit derived from an acrylate ester containing a —SO ₂ -containing cyclic group.
Here, -SO ₂ - and containing cyclic group, -SO ₂ - within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO ₂ - in the sulfur atom (S) Are cyclic groups that form part of the ring skeleton of the cyclic group.
In such a —SO ₂ -containing cyclic group, the ring is counted as one ring, and when it is only the ring, it is a monocyclic group, and when it has another ring structure, It is called a cyclic group. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
The —SO ₂ — containing cyclic group is particularly a cyclic group containing —O—SO ₂ — in its ring skeleton, that is, —O—S— in —O—SO ₂ — represents a part of the ring skeleton. The sultone ring to be formed is preferable.
The —SO ₂ — containing cyclic group 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 —SO ₂ — containing cyclic group may be an —SO ₂ — containing aliphatic cyclic group or an —SO ₂ — containing aromatic cyclic group. Preferably -SO ₂ - containing aliphatic cyclic group.
The —SO ₂ -containing aliphatic cyclic group includes at least a hydrogen atom from an aliphatic hydrocarbon ring in which a part of carbon atoms constituting the ring skeleton is substituted with —SO ₂ — or —O—SO ₂ —. One group is excluded. More specifically, a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —, —CH ₂ — constituting the ring And a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which CH ₂ — is substituted with —O—SO ₂ —.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms are removed from a C 3-6 monocycloalkane is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon 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, tetracyclododecane and the like.

The —SO ₂ — containing cyclic group 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 ″ (R ″ represents a hydrogen atom or an alkyl group). Group), a hydroxyalkyl group, a cyano group, and the like.
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 groups 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. Groups 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 the —SO ₂ -containing cyclic group include groups represented by the following general formulas (3-1) to (3-4).

［式中、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、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またはシアノ基であり、Ｒ”は水素原子またはアルキル基である。］

[In the formula, 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, for example, —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 of 0 to 2, and is most preferably 0.
When z is 2, the plurality of R ⁶ may be the same or different.
As the alkyl group, alkoxy group, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in R ⁶ , the —SO ₂ — containing cyclic group has the above-mentioned, respectively. And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups as those which may be substituted.
Specific examples of cyclic groups represented by the general formulas (3-1) to (3-4) are shown below. In the formula, “Ac” represents an acetyl group.

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

More specifically, examples of the structural unit (a2 ^S ) include structural units represented by general formula (a2-0) shown below.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^５は−ＳＯ_２−含有環式基であり、Ｒ^２９は単結合または２価の連結基である。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ⁵ is a —SO ₂ — containing cyclic group, and R ²⁹ is a single bond] Or it is a bivalent coupling group. ]

In formula (a2-0), R is the same as defined above.
R ⁵ is the same as the —SO ₂ — containing cyclic group mentioned above.
R ²⁹ may be a single bond or a divalent linking group. Since it is excellent in the effect of this invention, it is preferable that it is a bivalent coupling group.
The divalent linking group for R ²⁹ is not particularly limited. For example, as the divalent linking group for Y ² in the general formula (a1-0-2) mentioned in the description of the structural unit (a1). The thing similar to what was mentioned is mentioned. Among these, those containing an alkylene group or an ester bond (—C (═O) —O—) are preferable.
The alkylene group is 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 Y ² can be used.
As the divalent linking group containing an ester bond, in particular, the general formula: —R ⁴ —C (═O) —O— [wherein R ⁴ is a divalent linking group. ] Is preferable. That is, the structural unit (a2 ^S ) is preferably a structural unit represented by the following general formula (a2-0-1).

［式中、ＲおよびＲ^５はそれぞれ前記と同様であり、Ｒ^４は２価の連結基である。］

[Wherein, R and R ⁵ are the same as defined above, and R ⁴ is a divalent linking group. ]

R ⁴ is not particularly limited, and for example, the same as those mentioned as the divalent linking group for Y ² in the general formula (a1-0-2) mentioned in the description of the structural unit (a1). Things.
The divalent linking group for R ⁴ is preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom.
Examples of the linear or branched alkylene group, divalent alicyclic hydrocarbon group, and divalent linking group containing a hetero atom are the linear or branched groups mentioned above as preferred for Y ^2. Examples are the same as a chain alkylene group, a divalent alicyclic hydrocarbon group, and a divalent linking group containing a hetero atom.
Among these, a linear or branched alkylene group or a divalent linking group containing an oxygen atom as a hetero atom is preferable.
As the linear alkylene group, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable.
As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferable, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — is particularly preferable.
The divalent linking group containing an oxygen atom is preferably a divalent linking group containing an ether bond or an ester bond, and the above formulas -A-O-B-,-[A-C (= O) -O] _{m '} A group represented by -B- or -A-O-C (= O) -B- is more preferred.
Of these, a group represented by the formula —A—O—C (═O) —B— is preferable, and represented by — (CH ₂ ) _c —C (═O) —O— (CH ₂ ) _d —. The group is particularly preferred. c is an integer of 1 to 5, and 1 or 2 is preferable. d is an integer of 1-5, and 1 or 2 is preferable.

As the structural unit (a2 ^S ), a structural unit represented by general formula (a0-1-11) or (a0-1-12) shown below is particularly preferable, and represented by formula (a0-1-12). A structural unit is more preferable.

［式中、Ｒ、Ａ’、Ｒ^６、ｚおよびＲ^４はそれぞれ前記と同じである。］

[Wherein, R, A ′, R ⁶ , z and R ⁴ are the same as defined above. ]

In formula (a0-1-11), A ′ is preferably a methylene group, an oxygen atom (—O—) or a sulfur atom (—S—).
R ⁴ is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom. As the linear or branched alkylene group and the divalent linking group containing an oxygen atom in R ^4, the linear or branched alkylene group mentioned above and a divalent linking group containing an oxygen atom are mentioned. Examples are the same as the linking group.
As the structural unit represented by the formula (a0-1-12), a structural unit represented by the following general formula (a0-1-12a) or (a0-1-12b) is particularly preferable.

［式中、ＲおよびＡ’はそれぞれ前記と同じであり、ｃ〜ｅはそれぞれ独立に１〜３の整数である。］

[Wherein, R and A ′ are the same as defined above, and c to e are each independently an integer of 1 to 3.] ]

-Structural unit (a2 ^L ):
The structural unit (a2 ^L ) 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 a ring (lactone ring) containing —O—C (O) — in the ring skeleton. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group. When it has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone cyclic group in the structural unit (a2 ^L ) is not particularly limited, and any one can be used. Specifically, the lactone-containing monocyclic group is a group in which one hydrogen atom is removed from a 4- to 6-membered ring lactone, for example, a group in which one hydrogen atom is removed from β-propionolactone, or γ-butyrolactone. Examples include a group in which one hydrogen atom is removed, a group in which one hydrogen atom is removed from δ-valerolactone, and the like. 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.
Examples of the structural unit (a2 ^L ) include those in which R ⁵ in the general formula (a2-0) is substituted with a lactone-containing cyclic group, and more specifically, the following general formula (a2- The structural unit represented by 1)-(a2-5) is mentioned.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；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０〜２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である。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ′ is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, carbon An alkoxy group of 1 to 5 or —COOR ″, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group, and s ″ is an integer of 0 to 2; 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; m is 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.
The alkyl group in R ″ may be linear, branched or cyclic.
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 are removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, 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.
Examples of A ″ include the same as A ′ in the general formula (3-1). A ″ represents an alkylene group having 1 to 5 carbon atoms, an oxygen atom (—O—) or a sulfur atom (— S-) is preferable, and an alkylene group having 1 to 5 carbon atoms or -O- is more preferable. The alkylene group having 1 to 5 carbon atoms is more preferably a methylene group or dimethylmethylene group, and most preferably a methylene group.
R ²⁹ is the same as ^{R 29} in the aforementioned general formula (a2-0).
In formula (a2-1), s ″ is preferably 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.

As the structural unit (a2 ^L ), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formula (a2-1) to More preferably, at least one selected from the group consisting of structural units represented by (a2-3) is selected from the group consisting of structural units represented by the general formula (a2-1) or (a2-2) Particularly preferred is at least one of the above.
Among them, the formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-7), (a2-2-12), (a2-2-2-) 14), (a2-3-1), at least one selected from the group consisting of structural units represented by (a2-3-5) is preferred.

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. For example, as the structural unit (a2), only the structural unit (a2 ^S ) may be used, only the structural unit (a2 ^L ) may be used, or they may be used in combination. As the structural unit (a2 ^S ) or the structural unit (a2 ^L ), one type may be used alone, or two or more types may be used in combination.
In the present invention, it is particularly preferable to have at least the structural unit (a2 ^S ) as the structural unit (a2) because the effects of the present invention are excellent.

  In the component (A1), the proportion of the structural unit (a2) is preferably 1 to 80 mol%, and preferably 10 to 70 mol%, based on the total of all structural units constituting the component (A1). Is more preferable, it is more preferable that it is 10-65 mol%, and 10-60 mol% is especially 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, and lithography characteristics such as DOF can be achieved. improves.

(Structural unit (a3))
The structural unit (a3) is a structural unit (a3) 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.
The structural unit (a3) is a structural unit that does not correspond to the structural unit (a0). That is, even in the “structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group”, the structural unit corresponding to the structural unit represented by the general formula (a0-1) is a structural unit ( a0) and not the structural unit (a3).

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, a fluorinated alcohol group (a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom), and the like. Among these, a hydroxyl group and a carboxy group are preferable, and a hydroxyl group is particularly preferable.
In the structural unit (a3), the number of polar groups bonded to the aliphatic hydrocarbon group is not particularly limited, but is preferably 1 to 3, and most preferably 1.
The aliphatic hydrocarbon group to which the polar group is bonded may be saturated, unsaturated, or 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 12 carbon atoms, more preferably 1 to 10, more preferably 1 to 8, and further preferably 1 to 6. .
In the linear or branched aliphatic hydrocarbon group, part or all of the hydrogen atoms may be substituted with a substituent other than the polar group. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O). Further, the linear or branched aliphatic hydrocarbon group may have a divalent group containing a hetero atom between carbon atoms. The “divalent group containing a heteroatom” is the “heteroatom represented by the divalent linking group of Y ² in the general formula (a1-0-2) in the description of the structural unit (a1). The same thing as "the bivalent coupling group containing" is mentioned.
When the aliphatic hydrocarbon group is linear or branched, the structural unit (a3) is preferably a structural unit represented by the following general formula (a3-1) or (a3-2).

［式中、Ｒは前記に同じであり、Ｒ^８１は直鎖状または分岐鎖状のアルキレン基であり、Ｒ^８２は、ヘテロ原子を含む２価の基が介在してもよいアルキレン基である。］

[Wherein, R is the same as defined above, R ⁸¹ represents a linear or branched alkylene group, and R ⁸² represents an alkylene group which may be intervened by a divalent group containing a hetero atom. . ]

In formula (a3-1), the alkylene group for R ⁸¹ preferably has 1 to 12 carbon atoms, and more preferably 1 to 10 carbon atoms.
In formula (a3-2), the alkylene group for R ⁸² preferably has 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, and particularly preferably 1 to 6 carbon atoms.
When the alkylene group is an alkylene group having 2 or more carbon atoms, a divalent group containing a hetero atom may be interposed between carbon atoms of the alkylene group. The “divalent group containing a heteroatom” is the “heteroatom represented by the divalent linking group of Y ² in the general formula (a1-0-2) in the description of the structural unit (a1). The same thing as "the bivalent coupling group containing" is mentioned.
R ⁸² is particularly preferably an alkylene group in which a divalent group containing a hetero atom is not present, or an alkylene group in which a divalent group containing an oxygen atom is present as a hetero atom.
As the alkylene group intervening with a divalent group containing an oxygen atom, a group represented by -A-O-B- or -A-O-C (= O) -B- is preferable. In the formula, A and B are each independently a divalent hydrocarbon group which may have a substituent, and -A-O-B- or -A mentioned in the description of the structural unit (a1). The same thing as A and B in -OC (= O) -B- is mentioned.
Among these, a group represented by —A—O—C (═O) —B— is preferable, and — (CH ₂ ) _f —O—C (═O) — (CH ₂ ) _{g ′} — [formula In the formula, f and g ′ are each independently an integer of 1 to 3. ] Is preferable.

Examples of the “aliphatic hydrocarbon group including a ring in the structure” include a cyclic aliphatic hydrocarbon group, and whether the cyclic aliphatic hydrocarbon group is bonded to the terminal of the chain aliphatic hydrocarbon group described above. Or the group which intervenes in the middle of a chain-like aliphatic hydrocarbon group etc. are mentioned.
The cyclic aliphatic hydrocarbon group preferably has 3 to 30 carbon atoms. The cyclic aliphatic hydrocarbon group may be polycyclic, monocyclic, or polycyclic.
As the cyclic aliphatic hydrocarbon group, specifically, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from those proposed. For example, the monocyclic aliphatic hydrocarbon group is preferably a group in which two or more hydrogen atoms are removed from a monocycloalkane having 3 to 20 carbon atoms, and examples of the monocycloalkane include cyclopentane and cyclohexane. . The polycyclic aliphatic hydrocarbon group is preferably a group in which two or more hydrogen atoms are removed from a polycycloalkane having 7 to 30 carbon atoms. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane. , Tricyclodecane, tetracyclododecane and the like.
In the cyclic aliphatic hydrocarbon group, part or all of the hydrogen atoms may be substituted with a substituent other than the polar group. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).
When the aliphatic hydrocarbon group includes a ring in the structure, the structural unit (a3) is a structural unit represented by the following general formula (a3-3), (a3-4) or (a3-5) Is preferred.

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

[Wherein, R is the same as described 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 1 to 5] S ′ is an integer of 1 to 3. ]

In formula (a3-3), 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.
In formula (a3-4), k ′ is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-5), t ′ is preferably 1. l ′ is preferably 1. s ′ is preferably 1.
In formula (a3-5), the oxygen atom (—O—) of the carbonyloxy group is preferably bonded to the 2nd or 3rd position of the norbornane ring. The fluorinated alkyl alcohol group is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
The structural unit (a3) preferably has a structural unit represented by any one of the general formulas (a3-1) to (a3-5), and is represented by the general formula (a3-2). It is particularly preferred to have
In the component (A1), the proportion of the structural unit (a3) is preferably 1 to 50 mol%, more preferably 5 to 40 mol%, and more preferably 5 to 25 mol based on all structural units constituting the component (A1). % Is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) is sufficiently obtained, and by setting the upper limit value or less, it is possible to balance with other structural units.

(Structural unit (a4))
The structural unit (a4) is a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic cyclic group. When the component (A1) has the structural unit (a4), the resist pattern shape becomes favorable.
The “acid non-dissociable aliphatic cyclic group” is an aliphatic cyclic group that remains in the structural unit without being dissociated even when the acid acts when it is generated from the component (B) by exposure. is there.
The aliphatic cyclic group is not particularly limited as long as it is non-acid dissociable, and is used for a resin component of a resist composition for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), etc. Many known conventionally as can be used. The aliphatic cyclic group may be saturated, unsaturated, or saturated. Specific examples include groups in which one hydrogen atom has been removed from a cycloalkane such as monocycloalkane and polycycloalkane mentioned in the description of the aliphatic cyclic group in the structural unit (a1).
The aliphatic cyclic group may be monocyclic or polycyclic, and is preferably polycyclic because the above effects are excellent. In particular, those having 2 to 4 rings are preferable, and among them, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group and a norbornyl group is preferable in terms of industrial availability. .
Specific examples of the non-acid-dissociable aliphatic cyclic group include, for example, a carbon atom bonded to an atom adjacent to the aliphatic cyclic group (for example, —O— in —C (═O) —O—). And monovalent aliphatic cyclic groups to which substituents (atoms or groups other than hydrogen atoms) are not bonded. Specifically, a group in which R ¹⁴ in the groups represented by formulas (1-1) to (1-9) given in the description of the structural unit (a1) is substituted with a hydrogen atom; carbon constituting the ring skeleton And a group obtained by removing a hydrogen atom from the tertiary carbon atom of a cycloalkane having a tertiary carbon atom formed only by an atom.
A substituent may be bonded to the aliphatic cyclic group. As this substituent, a C1-C5 alkyl group, a fluorine atom, a fluorinated alkyl group etc. are mentioned, for example.
As the structural unit (a4), structural units represented by the following general formula (a4-0) are preferable, and structural units represented by the following general formulas (a4-1) to (a4-5) are particularly preferable.

［式中、Ｒは前記と同じであり、Ｒ^４０は酸非解離性の脂肪族多環式基である。］

[Wherein, R is the same as defined above, and R ⁴⁰ represents an acid non-dissociable aliphatic polycyclic group. ]

［式中、Ｒは前記と同じである。］

[Wherein, R is the same as defined above. ]

As the structural unit (a4), one type may be used alone, or two or more types may be used in combination.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) in the component (A1) is 1 to 30 mol% with respect to all the structural units constituting the component (A1). Preferably, 5 to 20 mol% is more preferable.

The component (A1) may contain other structural units other than the structural units (a1) to (a4) as long as the effects of the present invention are not impaired.
The other structural unit is not particularly limited as long as it is another structural unit not classified into the above structural units (a1) to (a4). For ArF excimer laser, for KrF excimer laser (preferably ArF excimer) A number of hitherto known materials can be used for resist resins such as lasers.

As the component (A1), a copolymer having the structural units (a0) and (a1) is preferable, and a copolymer having the structural units (a0), (a1) and (a2) is more preferable.
Examples of the copolymer include a copolymer composed of the structural units (a0) and (a1); a copolymer composed of the structural units (a0), (a1) and (a2); a structural unit (a0), ( a1), a copolymer comprising (a2) and (a3); a copolymer comprising structural units (a0), (a1), (a2) and (a4); a structural unit (a0), (a1), ( Examples thereof include a copolymer comprising a2), (a3) and (a4).
As a preferred component (A1), a copolymer having two types of structural units represented by the following formula (A1-21), and three types of structural units represented by the following formulas (A1-31) to (A1-38), respectively. A copolymer having four structural units represented by the following formulas (A1-41) to (A1-48), and five kinds represented by the following formulas (A1-51) to (A1-54), respectively. And a copolymer having the following structural unit.

［式中、Ｒ、Ｒ^２５およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁵ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^２９、Ｒ^２５およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , R ²⁵ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^２９、Ａ”、Ｒ^２５およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , A ″, R ²⁵ and W are the same as defined above, and the plurality of R in the formula may be the same or different.]

［式中、Ｒ、Ｒ^４、Ａ’、Ｒ^２５およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ⁴ , A ′, R ²⁵ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^４、Ａ’、Ｒ^２５およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ⁴ , A ′, R ²⁵ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ａ’、Ｒ^２５およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, A ′, R ²⁵ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^４、Ａ’、Ｒ^２３およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ⁴ , A ′, R ²³ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^４、Ａ’、Ｒ^２１、ｈおよびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ⁴ , A ′, R ²¹ , h and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^２９、Ｒ^２１、ｈおよびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , R ²¹ , h and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^４、Ａ’、Ｒ^２３、ａ、ｂ、Ｒ^１４およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ⁴ , A ′, R ²³ , a, b, R ¹⁴ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^４、Ａ’、Ｒ^２５、ａ、ｂ、Ｒ^１４およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ⁴ , A ′, R ²⁵ , a, b, R ¹⁴ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^４、Ａ’、Ｒ^２３、Ｒ^２５およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ⁴ , A ′, R ²³ , R ²⁵ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^２９、Ｒ^４、Ａ’、Ｒ^２３およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , R ⁴ , A ′, R ²³ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^２９、Ｒ^４、Ａ’、Ｒ^２５およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , R ⁴ , A ′, R ²⁵ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^２９、Ｒ^４、Ａ’、Ｒ^２１、ｈおよびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , R ⁴ , A ′, R ²¹ , h and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^４、Ａ’、Ｒ^２３、Ｒ^２１、ｈおよびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ⁴ , A ′, R ²³ , R ²¹ , h and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^２９、Ｒ^２５およびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , R ²⁵ and W are the same as defined above, and the plurality of R in the formula may be the same or different. ]

［式中、Ｒ、Ｒ^２９、Ｒ^４、Ａ’、Ｒ^２３、Ｒ^２１、ｈおよびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , R ⁴ , A ′, R ²³ , R ²¹ , h and W are the same as defined above, and a plurality of R in the formula may be the same or different. . ]

［式中、Ｒ、Ｒ^２９、Ｒ^４、Ａ’、Ｒ^２５、Ｒ^２１、ｈおよびＷはそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , R ⁴ , A ′, R ²⁵ , R ²¹ , h and W are the same as defined above, and a plurality of R in the formula may be the same or different from each other. . ]

［式中、Ｒ、Ｒ^２９、Ｒ^４、Ａ’、Ｒ^２３、Ｒ^２１、ｈ、ＷおよびＲ^８２はそれぞれ前記と同じであり、式中の複数のＲはそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, R ²⁹ , R ⁴ , A ′, R ²³ , R ²¹ , h, W and R ⁸² are the same as defined above, and a plurality of R in the formula are the same or different. May be. ]

［式中、Ｒ、ｅ、Ａ’、ｃ、ｄ、Ｒ^２３、ａ、ｂ、Ｒ^１４およびＷはそれぞれ前記と同じであり、式中の複数のＲ、複数のＡ’はそれぞれ同じであっても異なっていてもよい。］

[Wherein, R, e, A ′, c, d, R ²³ , a, b, R ¹⁴ and W are the same as defined above, and the plurality of R and A ′ in the formula are the same respectively. Or different. ]

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, and 2000 to 2000 20000 is more preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.0 to 2.5. Most preferred. In addition, Mn shows a number average molecular weight.

Component (A1) is a known monomer that uses a radical polymerization initiator such as dimethyl-2,2-azobis (2-methylpropionate) or azobisisobutyronitrile as a monomer for deriving each structural unit. It can be obtained by polymerizing by radical polymerization or the like.
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 into which a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom is introduced has reduced defects and LER (line edge roughness: uneven unevenness of line side walls). Effective for reduction.

As the monomer for deriving each structural unit, a commercially available monomer may be used, or a monomer produced by a known method may be used.
For example, the monomer for deriving the structural unit (a0) is a compound represented by the following general formula (I) (hereinafter referred to as compound (I)).
Although it does not specifically limit as a manufacturing method of compound (I), As a preferable method, it represents to the reaction system containing the compound represented with the following general formula (I-1) by the following general formula (I-2), for example. And a method of obtaining a compound (I) by adding an alcohol derivative.
Specific examples of the method for producing compound (I) include, for example, producing 3-sulfamoyloxyadamantan-1-yl acrylate by reacting 3-hydroxyadamantan-1-yl acrylate with ClSO ₂ NH _2. can do.

［式中のＲ、Ｗはそれぞれ前記式（ａ０−１）中のＲ、Ｗと同じであり、Ｘ^ｈはフッ素原子、塩素原子、臭素原子またはヨウ素原子である。］

[R in the formula, W is the same as each of R in general formula (a0-1), W, X ^h is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. ]

Further, for example, as a monomer for deriving the structural unit represented by the general formula (a2-0-1), a compound represented by the following general formula (II) (hereinafter referred to as the compound (II)) may be mentioned. .
The method for producing such compound (II) is not particularly limited, and can be produced using a known method. For example, a compound (II-) represented by the following general formula (II-2) is added to a solution of the compound (II-1) represented by the following general formula (II-1) in a reaction solvent in the presence of a base. The compound (II) 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.
In the above reaction, an acid may be used as necessary. 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.
A compound in which R ⁵ is a lactone-containing cyclic group can also be produced by the same method.

［式中のＲ、Ｒ^４、Ｒ^５はそれぞれ前記式（ａ２−０−１）中のＲ、Ｒ^４、Ｒ^５と同じである。］

^[R in the ^formula, R 4, ^{R 5} are the same each ^R in the formula (a2-0-1) ^in, and R 4, ^{R 5.} ]

The structure of the compound obtained as described above includes 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, elemental analysis method, X-ray crystal diffraction method, etc.

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 50% by mass, more preferably 80% by mass or more, and 100% by mass with respect to the total mass of the component (A).

The positive resist composition of the present invention does not correspond to the component (A1) as the component (A), and is a base material component (hereinafter referred to as “component (A2)”) that has increased solubility in an alkaline developer by the action of an acid. .) May be contained.
The component (A2) is not particularly limited, and many conventionally known base components for chemically amplified positive resist compositions (for example, for ArF excimer laser, for KrF excimer laser (preferably ArF) A base resin such as for excimer laser) may be arbitrarily selected and used. For example, the base resin for ArF excimer laser includes a resin having the structural unit (a1) as an essential structural unit and optionally further including the structural units (a2) to (a5). Moreover, you may contain the nonpolymer (low molecular compound) whose molecular weight is 500-4000.
(A2) A component may be used individually by 1 type and may be used in combination of 2 or more type.

  In the positive 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>
In the present invention, the component (B) is at least one acid generator (B1) selected from the group consisting of compounds represented by any one of the following general formulas (1) to (3) (hereinafter referred to as (B1) And an acid generator (B2) composed of a compound represented by the following general formula (4) (hereinafter referred to as “component (B2)”).

［式中、Ｘ^１０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、Ｑ^１はカルボニル基を含む２価の連結基であり、ｐは１〜３の整数であり；Ｘ^２０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、Ｑ^２は単結合またはアルキレン基であり、ｑは１〜３の整数であり；Ｘ^３０は置換基を有していてもよい炭素数１〜３０の炭化水素基であり、Ｑ^３は単結合または２価の連結基であり、Ｙ^１０はカルボニル基またはスルホニル基であり、Ｙ^１１は置換基を有していてもよい炭素数１〜１０のアルキル基または置換基を有していてもよい炭素数１〜１０のフッ素化アルキル基であり；Ａ^＋は対カチオンである。］

[Wherein, X ¹⁰ is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ¹ is a divalent linking group containing a carbonyl group, and p is an integer of 1 to 3. by ^{and; X 20} represents a hydrocarbon group having 3 to 30 carbon atoms which may have a substituent group, ^{Q 2} is a single bond or an alkylene group, q is an integer from 1 to ^{3; X 30} Is an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, Q ³ is a single bond or a divalent linking group, Y ¹⁰ is a carbonyl group or a sulfonyl group, and Y ¹¹ is An alkyl group having 1 to 10 carbon atoms which may have a substituent or a fluorinated alkyl group having 1 to 10 carbon atoms which may have a substituent; A ⁺ is a counter cation. ]

［式（４）中、Ｒ^０は置換基を有していてもよい炭素数１〜１２の炭化水素基である。ただし、−ＳＯ_３ ⁻における硫黄原子に隣接する炭素原子にはフッ素原子は結合していない。Ａｂ^＋は芳香族基を有する対カチオンである。］

[In Formula (4), ^R0 is a C1-C12 hydrocarbon group which may have a substituent. However, the fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in —SO ₃ ^— . Ab ⁺ is a counter cation having an aromatic group. ]

[Anion part of component (B1)]
First, the anion parts of the compounds represented by the general formulas (1), (2), and (3) will be described in order as the anion parts (1), (2), and (3), respectively.

{Anion part (1)}
In the formula (1), X ¹⁰ is a hydrocarbon group of 3 to 30 carbon atoms which may have a substituent.
The hydrocarbon group for X ¹⁰ may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The “aromatic hydrocarbon group” is an aromatic hydrocarbon group.
In X ^10, the carbon number of the aromatic hydrocarbon group is 3 to 30, preferably from 5 to 30, more preferably from 5 to 20, particularly preferably 6 to 15, 6 to 12 being most preferred. However, the carbon number does not include the carbon number in the substituent.
Examples of the aromatic hydrocarbon group include a hydrocarbon group having an aromatic ring. Specifically, a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, a phenanthryl group. Aryl groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring, such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc. An arylalkyl group etc. are mentioned. The number of carbon atoms of 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 a part of carbon atoms constituting the ring is substituted with the heteroatom.
When a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group is substituted with a hetero atom, the atom bonded to the adjacent Q ¹ in X ¹⁰ is preferably a carbon atom.

In the latter example, examples of the substituent that replaces the hydrogen atom of the aromatic hydrocarbon group include an alkyl group, a halogen atom, an alkoxy group, a hydroxyl group, —C (═O) —R ⁸⁰ [R ⁸⁰ is an alkyl group. . ], -COOR ⁸³ [R ⁸³ is a hydrogen atom or an alkyl group. ^{], - OC (= O)} -R 84 [R 84 is a hydrogen atom or an alkyl group. ], Halogenated alkyl groups, halogenated alkoxy groups, hydroxyalkyl groups, oxygen atoms (═O), sulfur atoms, sulfonyl groups (SO ₂ ), hydrocarbon groups containing nitrogen atoms, other nitrogen-containing substituents, and the like. It is done.
The alkyl group as the substituent may be linear, branched or cyclic, or a combination thereof. The carbon number is preferably 1-30.
When the alkyl group is linear or branched, the carbon number is preferably 1-20, more preferably 1-17, still more preferably 1-15, 10 is particularly preferred. Specific examples thereof include those similar to the specific examples of the linear or branched saturated hydrocarbon group exemplified below. The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, particularly preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group.
When the alkyl group is cyclic (when it is a cycloalkyl group), the carbon number is preferably 3 to 30, more preferably 3 to 20, still more preferably 3 to 15, and 4 to 12 carbon atoms. It is particularly preferred that the number of carbon atoms is 5-10. The alkyl group may be monocyclic or polycyclic. Specific examples include groups obtained by removing one or more hydrogen atoms from a monocycloalkane, groups obtained by removing one or more hydrogen atoms from a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. . Specific examples of the monocycloalkane include cyclopentane and cyclohexane. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. In these cycloalkyl groups, some or all of the hydrogen atoms bonded to the ring may or may not be substituted with a substituent such as a fluorine atom or a fluorinated alkyl group.

Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the alkoxy group as the substituent include those in which an oxygen atom (—O—) is bonded to the alkyl group as the substituent described above. The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
In —C (═O) —R ⁸⁰ , —COOR ⁸³ , —OC (═O) —R ⁸⁴ as the substituent, the alkyl group in R ⁸⁰ , R ⁸³ , and R ⁸⁴ is alkyl as the substituent. The thing similar to what was mentioned as a group is mentioned.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is particularly preferred.
Examples of the halogenated alkoxy group as the substituent include groups in which some or all of the hydrogen atoms of the alkoxy group have been substituted with the halogen atoms. The halogenated alkoxy group is preferably a fluorinated alkoxy group.
Examples of the hydroxyalkyl group as the substituent include a group in which at least one hydrogen atom of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. 1-3 are preferable and, as for the number of the hydroxyl groups which a hydroxyalkyl group has, 1 is the most preferable.
The hydrocarbon group containing a nitrogen atom and other nitrogen-containing substituents will be described later.

An “aliphatic hydrocarbon group” is a hydrocarbon group having no aromaticity.
The aliphatic hydrocarbon group for X ¹⁰ may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched, or cyclic, or a combination thereof.
In X ¹⁰ , the aliphatic hydrocarbon group may be a group in which a part of carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom, and hydrogen constituting the aliphatic hydrocarbon group A part or all of the atoms may be substituted with a substituent containing a hetero atom.
The hetero atom 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 heteroatom (hereinafter sometimes referred to as a heteroatom-containing substituent) may be composed only of a heteroatom, or may be a group containing a group other than the heteroatom or an atom. .

Examples of the hetero atom-containing substituent that may substitute a part of carbon atoms constituting the aliphatic hydrocarbon 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- , and the like. In the case of -NH-, the substituent (alkyl group, acyl group, etc.) that may substitute for H preferably has 1 to 10 carbon atoms, and more preferably 1 to 8 carbon atoms. Particularly preferably, it has 1 to 5 carbon atoms. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.

Examples of the hetero atom-containing substituent that may substitute part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group include a halogen atom, an alkoxy group, a hydroxyl group, —C (═O) —R ⁸⁰ [ R ⁸⁰ is an alkyl group. ], -COOR ⁸³ [R ⁸³ is a hydrogen atom or an alkyl group. ^{], - OC (= O)} -R 84 [R 84 is a hydrogen atom or an alkyl group. ], Halogenated alkyl groups, halogenated alkoxy groups, hydroxyalkyl groups, oxygen atoms (═O), sulfur atoms, sulfonyl groups (SO ₂ ), hydrocarbon groups containing nitrogen atoms, other nitrogen-containing substituents, and the like. It is done.
Halogen atom, alkoxy group, —C (═O) —R ⁸⁰ , —COOR ⁸³ , —OC (═O) —R ⁸⁴ , halogenated alkyl group, halogenated alkoxy group, hydroxyalkyl as the heteroatom-containing substituent Examples of the group, the hydrocarbon group containing a nitrogen atom, and other nitrogen-containing substituents are the same as those exemplified as the substituent for substituting the hydrogen atom of the aromatic hydrocarbon group.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred. A group in which a linear or branched saturated hydrocarbon group or unsaturated hydrocarbon group is bonded to an aliphatic cyclic group is also preferred.
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, decyl 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. As the unsaturated hydrocarbon group, a propenyl group is particularly preferable.

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 obtained by removing one or more hydrogen atoms 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 groups represented by the following formulas (L1) to (L5) and (S1) to (S4).

［式中、Ｑ”は、酸素原子もしくは硫黄原子を含んでいてもよいアルキレン基、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 Q ″ is an alkylene group, an oxygen atom or a sulfur atom which may contain an oxygen atom or a sulfur atom, and m is an integer of 0 or 1.]

In the formula, the alkylene group in Q ″ is preferably linear or branched, and preferably has 1 to 5 carbon atoms. Specifically, 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 )-, an alkylmethylene group such as —C (CH ₂ CH ₃ ) ₂ —; an 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 -, - C (CH 2 CH 3) 2 CH 2 - alkyl groups such as, trimethylene group (n- Propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH _{2 CH 2 -, - CH 2} CH (CH 3) CH 2 - and the like alkyl trimethylene group; tetramethylene group _{[-CH 2 CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 CH _{2 -, - CH 2 CH (} CH 3) CH 2 CH 2 - and the like alkyl tetramethylene group;. a pentamethylene group _{[-CH 2 CH 2 CH 2 CH} 2 CH 2 -] , and the like among these, methylene Group or an alkylmethylene group is preferable, and a methylene group, —CH (CH ₃ ) — or —C (CH ₃ ) ₂ — is particularly preferable.
The alkylene group may contain an oxygen atom (—O—) or a sulfur atom (—S—). Specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, and examples thereof include —O—R ⁵⁴ —, —S—R ⁵⁵ —, and —R ⁵⁶ —. ^{O-R 57 -, - R} 58 -S-R 59 - , and the like. Here, R ^{54 to} R ⁵⁹ are each independently an alkylene group, and examples thereof include the same alkylene groups as those described above as the alkylene group in Q ″.
The Q ", among _{others, -O-CH 2 -, -} CH 2 -O-CH 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - and the like are preferable.

In these aliphatic cyclic groups, some or all of the hydrogen atoms may be substituted with substituents. Examples of the substituent include an alkyl group, a halogen atom, an alkoxy group, a hydroxyl group, —C (═O) —R ⁸⁰ [R ⁸⁰ is an alkyl group. ], -COOR ⁸³ [R ⁸³ is a hydrogen atom or an alkyl group. ^{], - OC (= O)} -R 84 [R 84 is a hydrogen atom or an alkyl group. ], A halogenated alkyl group, a halogenated alkoxy group, a hydroxyalkyl group, an oxygen atom (═O), a sulfur atom, a sulfonyl group (SO ₂ ), a substituent containing a nitrogen atom, and the like.
As the substituent, an alkyl group, a halogen atom, an alkoxy group, —C (═O) —R ⁸⁰ , —COOR ⁸³ , —OC (═O) —R ⁸⁴ , a halogenated alkyl group, a halogenated alkoxy group, a hydroxyalkyl Examples of the group, the hydrocarbon group containing a nitrogen atom, and other nitrogen-containing substituents are the same as those exemplified as the substituent for substituting the hydrogen atom of the aromatic hydrocarbon group.
The number of the substituents that the aliphatic cyclic group has may be one or two or more. When having a plurality of substituents, the plurality of substituents may be the same or different.

  Examples of the group in which a linear or branched saturated hydrocarbon group or unsaturated hydrocarbon group is bonded to an aliphatic cyclic group include, for example, a direct bond to a carbon atom constituting the ring structure of the aliphatic cyclic group. A group in which a linear or branched saturated hydrocarbon group is bonded is preferable, a group in which a linear saturated hydrocarbon group is bonded to the carbon atom is more preferable, and a linear alkylene group is bonded to the carbon atom. The group is particularly preferred.

Among the above, X ¹⁰ is preferably 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. Examples of the polycyclic aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from the polycycloalkane, and groups represented by the above (L2) to (L5) and (S3) to (S4). Etc. are preferred.

X ¹⁰ is also preferably a hydrocarbon group containing a nitrogen atom.
The hydrocarbon group containing a nitrogen atom includes a heterocyclic group containing a nitrogen atom as a hetero atom (hereinafter referred to as “nitrogen-containing heterocyclic group”) and a substituent containing a nitrogen atom (hereinafter referred to as “nitrogen-containing substituent”). .)) And the like. Among these, a nitrogen-containing heterocyclic group is preferable.
The hydrocarbon group containing a nitrogen atom may have a substituent not containing a nitrogen atom (hereinafter referred to as “non-nitrogen-containing substituent”).
Examples of the non-nitrogen-containing substituent include an alkyl group, a halogen atom, an alkoxy group, a hydroxyl group, and —C (═O) —R ⁸⁰ [R ⁸⁰ is an alkyl group. ], -COOR ⁸³ [R ⁸³ is a hydrogen atom or an alkyl group. ^{], - OC (= O)} -R 84 [R 84 is a hydrogen atom or an alkyl group. ], A halogenated alkyl group, a halogenated alkoxy group, a hydroxyalkyl group, an oxygen atom (═O), a sulfur atom, a sulfonyl group (SO ₂ ), an aryl group, and the like.
As the substituent, an alkyl group, a halogen atom, an alkoxy group, —C (═O) —R ⁸⁰ , —COOR ⁸³ , —OC (═O) —R ⁸⁴ , a halogenated alkyl group, a halogenated alkoxy group, a hydroxyalkyl Examples of the group include the same groups as those exemplified as the substituent for substituting the hydrogen atom of the aromatic hydrocarbon group.
Examples of the aryl group include the same aryl groups as those exemplified as the aromatic hydrocarbon group for X ¹⁰ , and a phenyl group, a tolyl group, a naphthyl group, and the like are preferable.

Examples of the nitrogen-containing heterocyclic group include groups in which one hydrogen atom has been removed from a heterocycle containing a nitrogen atom as a hetero atom (nitrogen-containing heterocycle).
As nitrogen-containing heterocycles, unsaturated monocycles such as pyridine, pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, pyrimidine, pyrazine, 1,3,5-triazine Saturated monocyclic nitrogen-containing heterocycles such as piperidine, piperazine, pyrrolidine; quinoline, isoquinoline, indole, pyrrolo [2,3-b] pyridine, indazole, benzimidazole (benzimidazole), benzotriazole, Carbazole, acridine, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2. 2.2] Polycyclic nitrogen-containing heterocycles such as octane.
The nitrogen-containing heterocyclic group may be monocyclic or polycyclic. The nitrogen-containing heterocyclic group has 3 to 30 carbon atoms, preferably 5 to 30 and more preferably 5 to 20.
The nitrogen-containing heterocyclic group in X ^10, 2-pyridyl, 3-pyridyl, 4-pyridyl group, piperidino group are preferred, 2-pyridyl group is particularly preferred.
In these nitrogen-containing heterocyclic groups, some or all of the hydrogen atoms may be substituted with nitrogen-containing substituents or non-nitrogen-containing substituents.

The hydrocarbon group having a nitrogen-containing substituent is a hydrocarbon group in which part or all of the hydrogen atoms are substituted with a nitrogen-containing substituent.
The hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Examples of the aromatic hydrocarbon group and the aliphatic hydrocarbon group are the same as the aromatic hydrocarbon group and the aliphatic hydrocarbon group mentioned in the description of the “hydrocarbon group of X ¹⁰ ”. .
As a nitrogen-containing substituent, the above-mentioned nitrogen-containing heterocyclic group is mentioned, for example. Other nitrogen-containing substituents include non-hydrocarbon-containing groups such as amino groups (—NH ₂ ), imino groups (═NH), cyano groups (—CN), ammonio groups (—NH ₃ ⁺ ), and nitro groups. A nitrogen substituent is mentioned.
In these nitrogen-containing substituents, some or all of the hydrogen atoms may be substituted with non-nitrogen-containing substituents. Examples of the nitrogen-containing substituent substituted with a non-nitrogen-containing substituent include an alkylamino group, an amide group, a dialkylamino group, an alkylimino group, and a trialkylammonio group.
Specific examples of the hydrocarbon group having a nitrogen-containing substituent include aminoalkyl groups such as aminomethyl group, 1-aminoethyl group and 2-aminoethyl group; alkylaminoalkyl groups such as methylaminomethyl group; dimethylaminomethyl Dialkylaminoalkyl groups such as 2-aminophenyl groups, aminoaryl groups such as 4-aminophenyl groups; alkylaminoaryl groups such as (methylamino) phenyl groups; (dimethylamino) phenyl groups, (diethylamino) phenyl groups And the like, and the like.

In the formula (1), Q ¹ is a divalent linking group containing a carbonyl group.
Q ¹ may contain atoms other than carbon atoms and oxygen atoms. Examples of atoms other than carbon atoms and oxygen atoms include a hydrogen atom, a sulfur atom, and a nitrogen atom.
Examples of the divalent linking group containing a carbonyl group include an ester bond (—C (═O) —O—), an amide bond (—C (═O) —NH—), and a carbonyl group (—C (═O )-), Non-hydrocarbon carbonyl group-containing linking groups such as carbonate bonds (—O—C (═O) —O—); and groups containing the non-hydrocarbon carbonyl group-containing linking groups.
Examples of the group containing a non-hydrocarbon carbonyl group-containing linking group include a combination of the non-hydrocarbon carbonyl group-containing linking group and a group selected from an alkylene group, an oxygen atom (ether bond: —O—), and the like. Can be mentioned.
Examples of the combination include —R ⁹¹ —O—C (═O) —, —O—R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —, —C. (═O) —O—R ⁹⁴ —O—, —C (═O) —O—R ⁹⁵ —O—C (═O) —, —R ⁹⁶ —C (═O) —O—R ⁹⁷ —O —, —R ⁹⁸ —C (═O) —O—R ⁹⁹ —O—C (═O) — wherein R ^{91 to} R ⁹⁹ are each independently an alkylene group. ] Etc. are mentioned.
The alkylene group in R ^{91 to} R ⁹⁹ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —, Alkylethylene groups such as —C (CH ₂ CH ₃ ) ₂ CH ₂ —; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ CH ₂ —, — Alkyl trimethylene groups such as CH ₂ CH (CH ₃ ) CH ₂ —; A tetramethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ —]; an alkyl tetramethylene group such as —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ CH ₂ —; A pentamethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like can be mentioned.
Q ¹ preferably contains an ester bond.

In the formula (1), p is an integer of 1 to 3, preferably 1 or 2, and most preferably 1.
As an anion part (1), what is represented by following General formula (11) is preferable.

［式（１１）中、Ｘ^１０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、Ｑ^１２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〜ｍ３はそれぞれ０または１である。ただし、ｍ２＋ｍ３、ｍ１＋ｍ３はいずれも０とならない。］

[In the formula (11), X ¹⁰ is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ¹² is a single bond or an alkylene group, and p is an integer of 1 to 3. And m1 to m3 are each 0 or 1. However, neither m2 + m3 nor m1 + m3 is 0. ]

In the formula (11), X ¹⁰ and p are the same as X ¹⁰ and p in the formula (1), respectively.
Examples of the alkylene group for Q ¹² include the same alkylene groups as those described above for R ^{91 to} R ^{99 in} the description of Q ¹ .
m1 to m3 are each 0 or 1. However, neither m2 + m3 nor m1 + m3 is 0. That is, m2 + m3 and m1 + m3 are both 1 or 2. For example, when m3 = 0, m2 is 1 and m1 is 1.
As the anion part (1), those selected from the group consisting of anion parts represented by any one of the following general formulas (11a) to (11d) are particularly preferable.

［式（１１ａ）中、Ｘ^１０、Ｑ^１２およびｐはそれぞれ前記と同じである。式（１１ｂ）中、Ｘ^１０およびｐはそれぞれ前記と同じであり、Ｑ^１３はアルキレン基である。式（１１ｃ）中、Ｘ^１０’は置換基を有していてもよいフッ素化アリール基であり、Ｑ^１４は単結合またはアルキレン基であり、ｐは前記と同じである。式（１１ｄ）中、Ｘ^１０”は置換基を有していてもよい脂肪族環式基であり、Ｑ^１５は置換基を有していてもよいアルキレン基であり、ｐは前記と同じである。］

[In the formula (11a), X ¹⁰ , Q ¹² and p are the same as defined above. In formula (11b), X ¹⁰ and p are the same as defined above, and Q ¹³ is an alkylene group. In formula (11c), X ¹⁰ ′ is a fluorinated aryl group which may have a substituent, Q ¹⁴ is a single bond or an alkylene group, and p is the same as described above. In formula (11d), X ¹⁰ ″ represents an aliphatic cyclic group which may have a substituent, Q ¹⁵ represents an alkylene group which may have a substituent, and p is the same as described above. is there.]

In the formula (11a), X ¹⁰ , Q ¹² and p are the same as X ¹⁰ , Q ¹² and p in the formula (11), respectively.
X ¹⁰ is an aliphatic cyclic group which may have a substituent, a linear aliphatic hydrocarbon group which may have a substituent, or an aromatic which may have a substituent. A group hydrocarbon group is preferred. Among these, an aliphatic cyclic group containing a substituent containing a hetero atom in the ring structure is preferable.
Q ¹² is particularly preferably a single bond or a methylene group. In particular, when X ¹⁰ is an aliphatic cyclic group which may have a substituent, Q ¹² is preferably a single bond, and when X ¹⁰ is an aromatic hydrocarbon group, Q ¹² Is preferably a methylene group.
p is preferably 1 or 2, and most preferably 1.
Preferred specific examples of the anion moiety represented by the general formula (11a) are given below.

［式中、Ｑ”は前記と同じであり、Ｒ^７”は置換基であり、ｗ１〜ｗ３はそれぞれ独立に０〜３の整数であり、ｖ１〜ｖ３はそれぞれ独立に０〜５の整数であり、ｐは１〜３の整数である。］

[Wherein, Q ″ is the same as defined above, R ⁷ ″ is a substituent, w1 to w3 are each independently an integer of 0 to 3, and v1 to v3 are each independently an integer of 0 to 5. Yes, p is an integer from 1 to 3. ]

In formulas (11a-1) to (11a-3), as the substituent for R ⁷ ″, a part or all of the hydrogen atoms of the aliphatic cyclic group may be substituted in the description of X ¹⁰ above. The thing similar to what was mentioned as a substituent is mentioned.
When the code | symbol (w1-w3) attached | subjected to R < ⁷ >'' is an integer greater than or equal to 2, several R < ⁷ >'' in the said compound may be the same respectively, and may differ.
v1 to v3 are each independently preferably 0 to 3, and most preferably 0.
w1 to w3 are each independently preferably 0 to 2, and most preferably 0.
p is preferably 1 or 2, and most preferably 1.

In formula (11b), X ¹⁰ and p are the same as X ¹⁰ and p in formula (11), respectively.
X ¹⁰ is an aliphatic cyclic group which may have a substituent, a linear aliphatic hydrocarbon group which may have a substituent, or an aromatic which may have a substituent. A group hydrocarbon group is preferred.
p is preferably 1 or 2, and most preferably 1.
As the alkylene group for Q ^13, the same alkylene groups as those described above for Q ¹ can be mentioned.
Specific examples of preferred anion moieties represented by general formula (11b) are given below.

［式中、ｐは前記と同じであり、Ｒ^７”は置換基であり、ｒ１〜ｒ３はそれぞれ独立に０〜３の整数であり、ｑ１〜ｑ４はそれぞれ独立に１〜１２の整数であり、ｇは１〜２０の整数である。］

[Wherein, p is the same as defined above, R ⁷ ″ is a substituent, r1 to r3 are each independently an integer of 0 to 3, and q1 to q4 are each independently an integer of 1 to 12. , G is an integer of 1-20.]

Wherein (11b-1) ~ (11b -4), " as is, the formula (11a-1) ~ ^{R 7} in (11a-3) in" ^{R 7} include the same.
When the sign (r1 to r3) attached to R ⁷ ″ is an integer of 2 or more, the plurality of R ⁷ ″ in the compound may be the same or different.
r1 to r3 are each independently preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.
q1 to q4 are each independently 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.

In the formula (11c), p is the same as p in the formula (11), preferably 1 or 2, and most preferably 1.
In X ¹⁰ ′, the “fluorinated aryl group” is an aryl group in which at least one hydrogen atom is substituted with a fluorine atom. As the aryl group, the same aryl groups as mentioned in the description of the aromatic hydrocarbon group for X ¹⁰ can be mentioned, and a phenyl group or a naphthyl group is preferable, and a phenyl group is particularly preferable.
The aryl group may have a substituent other than a fluorine atom. Examples of the substituent are the same as those described as the substituent for substituting the hydrogen atom of the aromatic hydrocarbon group in the description of the aromatic hydrocarbon group in X ¹⁰ (excluding the fluorine atom). It is done.
As the alkylene group for Q ^14, the same alkylene groups as those described above for Q ¹ can be mentioned. Q ¹⁴ is preferably a single bond or a linear alkylene group. As the alkylene group, an alkylene group having 1 to 5 carbon atoms is particularly preferable.
Preferred specific examples of the anion moiety represented by the general formula (11c) are given below.

［式中、ｐは前記と同じであり、ｑ５は０〜５の整数であり、Ｒ^２’は置換基（ただしフッ素原子を除く。）であり、ｂは０〜２の整数であり、ｃは１〜５の整数であり、かつ１≦ｂ＋ｃ≦５である。］

[Wherein, p is the same as described above, q5 is an integer of 0 to 5, R ² ′ is a substituent (excluding a fluorine atom), b is an integer of 0 to 2, and c Is an integer from 1 to 5 and 1 ≦ b + c ≦ 5. ]

In formula (11c-1), q5 is preferably 1 to 4, more preferably 1 or 2, and most preferably 2.
Wherein (11c), 'as is the formula (but excluding fluorine atom.) (11a-1) ~ (11a-3) include those similar to the ^{R 7} "in. ^{R 2' R 2} as Is an alkyl group, an alkoxy group, a halogen atom (excluding a fluorine atom), a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ⁸³ , —OC (═O) R ⁸⁴ , a hydroxyalkyl group. Or a cyano group is preferable.
When b is 2, the plurality of R ² ′ in the compound may be the same or different.
b is most preferably 0.
c is preferably 2 to 5, and most preferably 5.
However, 1 ≦ b + c ≦ 5.

In formula (11c), p is the same as p in the formula (11).
p is preferably 1 or 2, and most preferably 1.
In X ¹⁰ ″, examples of the aliphatic cyclic group include the same aliphatic cyclic groups as those described above for the aliphatic hydrocarbon group for X ¹⁰ , and an adamantyl group is particularly preferable.
The aliphatic cyclic group may have a substituent. Examples of the substituent include the same substituents as those described as the substituent for substituting part or all of the hydrogen atoms of the aliphatic cyclic group in the description of the aliphatic cyclic group.
As the alkylene group for Q ^15, the same alkylene groups as those described above for Q ¹ can be mentioned. Q ¹⁵ is preferably a linear or branched alkylene group. The alkylene group preferably has 1 to 12 carbon atoms in the main chain. 1-5 are more preferable, as for this carbon number, 1-3 are more preferable, and 1 is especially preferable. That is, the Q ^15, a methylene group or an alkylmethylene group is particularly preferred. The alkyl group in the alkylmethylene group is preferably an alkyl group having 1 to 5 carbon atoms.
The alkylene group may have a substituent. Examples of the substituent include the same as those described as the substituent that the aliphatic hydrocarbon group may have in the description of the aliphatic hydrocarbon group in X ¹⁰ above, preferably a halogen atom, A fluorine atom is particularly preferred.
Preferred specific examples of the anion moiety represented by the general formula (11d) are given below.

［式中、ｐは前記と同じであり、ｑ６は１〜１２の整数であり、ｗ４は０〜３の整数であり、Ｒ^７”は置換基であり、Ｒ^１１”は水素原子、炭素数１〜５のアルキル基、炭素数１〜５のハロゲン化アルキル基である。］

[Wherein, p is the same as defined above, q6 is an integer of 1 to 12, w4 is an integer of 0 to 3, R ⁷ ″ is a substituent, R ¹¹ ″ is a hydrogen atom, a carbon number] An alkyl group having 1 to 5 carbon atoms, and a halogenated alkyl group having 1 to 5 carbon atoms. ]

In the formula, q6 is preferably 1 to 5, more preferably 1 to 3, and most preferably 1.
w4 is preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.
"Examples of the substituent of the formula (11a-1) ~ ^{R 7} in (11a-3) in" R ⁷ include the same. R ⁷ ″ is preferably an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ⁸³ , —OC (═O) R ⁸⁴ , a hydroxyalkyl group or a cyano group. .
When the sign (w4) attached to R ⁷ ″ is an integer of 2 or more, the plurality of R ⁷ ″ in the compound may be the same or different.
R ¹¹ ″ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

{Anion part (2)}
In the formula (2), X ²⁰ is a hydrocarbon group of 3 to 30 carbon atoms which may have a substituent. Examples of X ²⁰ include the same as X ¹⁰ in formula (1).
Q ² is a single bond or an alkylene group.
The alkylene group for Q ² is preferably a linear or branched alkylene group. 1-12 are preferable, as for carbon number of this alkylene group, 1-5 are more preferable, and 1-3 are especially preferable. Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —, Alkylethylene groups such as —C (CH ₂ CH ₃ ) ₂ CH ₂ —; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ CH ₂ —, — Alkyl trimethylene groups such as CH ₂ CH (CH ₃ ) CH ₂ —; A tetramethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ —]; an alkyl tetramethylene group such as —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ CH ₂ —; A pentamethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like can be mentioned.
q is an integer of 1 to 3, preferably 1 or 2, and most preferably 2.
Preferred specific examples of the anion portion (2) are listed below.

［式中、Ｒ^７”は置換基であり、ｗ０１〜ｗ０３はそれぞれ独立に０〜３の整数であり、ｖ０１〜ｖ０３はそれぞれ独立に０〜５の整数であり、ｑは前記と同じである。］

[Wherein R ⁷ ″ is a substituent, w01 to w03 are each independently an integer of 0 to 3, v01 to v03 are each independently an integer of 0 to 5, and q is the same as above. .]

Wherein (2a) ~ (2c), " as the substituent of the formula (11a-1) ~ ^{R 7} in (11a-3) in" ^{R 7} include the same.
When the code | symbol (w01-w03) attached | subjected to R < ⁷ >'' is an integer greater than or equal to 2, several R < ⁷ >'' in the said compound may be the same respectively, and may differ.
v01 to v03 are each independently preferably 0 to 3, and more preferably 0 or 1.
w01 to w03 are each independently preferably 0 to 2, and most preferably 0.

{Anion part (3)}
In the formula (3), X ³⁰ is a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent. Examples of X ³⁰ include the same as X ¹⁰ in the formula (1).
X ³⁰ is preferably a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or an optionally substituted cyclic group. . A group in which a linear or branched saturated hydrocarbon group or unsaturated hydrocarbon group is bonded to a cyclic group which may have a substituent is also preferable.
X ³⁰ is preferably a cyclic group which may have a substituent among the above.
The cyclic group may be an aromatic hydrocarbon group which may have a substituent, or an aliphatic cyclic group which may have a substituent.
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, (L2) to (L5), (S3) to (S4), and the like.

In the formula (3), Q ³ is a single bond or a divalent linking group.
Examples of the divalent linking group for Q ³ are the same as those described as the divalent linking group for Y ² in formula (a1-0-2) in the description of the structural unit (a1). A divalent hydrocarbon group which may have a substituent or a divalent linking group containing a hetero atom is preferable.
The divalent hydrocarbon group which may have a substituent is preferably an alkylene group or a fluorinated alkylene group. The alkylene group or fluorinated alkylene group is preferably linear or branched. 1-12 are respectively preferable, as for carbon number of this alkylene group or a fluorinated alkylene group, 1-5 are more preferable, 1-4 are more preferable, and 1-3 are especially preferable.
Specific examples of the alkylene group for Q ³ include the same alkylene groups as those described above for Q ² .
As the fluorinated alkylene group for Q ^3, part or all of the hydrogen atoms of the alkylene group include groups that are substituted with a fluorine atom in the Q ^3, _{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 -, - C _{(CF 3) CH 2 -,} - CH (CF 2 CF 3) -, - C (CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - CH 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 - , etc. Is mentioned.
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.

The divalent linking group containing a hetero atom is preferably one containing at least an oxygen atom as a hetero atom, preferably an oxygen atom (ether bond; —O—) or an ester bond (—C (═O) —O. -), Amide bond (-C (= O) -NH-), carbonyl group (-C (= O)-), carbonate bond (-O-C (= O) -O-), etc. And a combination of the non-hydrocarbon oxygen atom-containing linking group and an alkylene group or a fluorinated alkylene group.
Examples of the combination of the non-hydrocarbon-based oxygen atom-containing linking group and the alkylene group or fluorinated alkylene group described above include, for example, —R ¹⁰¹ —O—, —O—R ¹⁰² —O—C (═O) —, —C (═O) —O—R ¹⁰³ —, —C (═O) —O—R ¹⁰⁴ —O—, —C (═O) —O—R ¹⁰⁵ —O—C (═O) —, — R ¹⁰⁶ —C (═O) —O—R ¹⁰⁷ —O—, —R ¹⁰⁸ —C (═O) —O—R ¹⁰⁹ —O—C (═O) — wherein R ^{101 to} R ¹⁰⁹ are Each independently represents an alkylene group or a fluorinated alkylene group. ] Etc. are mentioned. In the formula, examples of the alkylene group and the fluorinated alkylene group for R ^{101 to} R ¹⁰⁹ include the same groups as those described above for the alkylene group and the fluorinated alkylene group for Q ³ .

Q ³ is preferably a single bond, an alkylene group, a fluorinated alkylene group, or a divalent linking group containing an ether bond, more preferably a single bond, an alkylene group, or —R ¹⁰¹ —O—.
In particular, when Y ¹⁰ in formula (3) is a sulfonyl group, Q ³ is preferably a fluorinated alkylene group, and in particular, a carbon atom bonded to a sulfur atom in adjacent Y ¹⁰ is fluorinated. The fluorinated alkylene group is preferably. Thereby, the acid which has strong acid strength by exposure is generated from the component (B1). Thereby, the resist pattern shape becomes better, and the lithography characteristics such as EL margin are improved.
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.
In the case Y ¹⁰ in the formula (3) is a sulfonyl group, by adjusting the number of fluorine atoms in Q ^3, it is possible to adjust the acid strength of the acid generated upon exposure. When the above-mentioned carbon atom is not fluorinated, the acid strength becomes weak, but an effect such as improvement of roughness can be expected.

In Formula (3), Y ¹⁰ represents a carbonyl group (—C (═O) —) or a sulfonyl group (—S (═O) ₂ —).
Y ¹¹ is an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted fluorinated alkyl group having 1 to 10 carbon atoms.
1-8 are preferable and, as for carbon number of this alkyl group or a fluorinated alkyl group, 1-4 are more preferable. In particular, when Y ¹¹ is a fluorinated alkyl group having 1 to 4 carbon atoms, the decomposability of the skeleton of “Y ¹¹ —SO ₂ —” in formula (3) is, for example, a perfluoroalkyl chain having 6 to 10 carbon atoms. Is difficult to decompose and is good, and the effect that the handleability considering bioaccumulation is further improved is also obtained. Moreover, it is preferable also from being easy to distribute uniformly in a resist film.
Specific examples of the alkyl group or a fluorinated alkyl group, the same alkyl group or a fluorinated alkyl group mentioned in the Q ³ and the like.
Y ¹¹ is preferably a fluorinated alkyl group which may have a substituent since the strength of the generated acid is strong. The fluorination rate of the fluorinated alkyl group (ratio of the number of fluorine atoms to the total number of fluorine atoms and hydrogen atoms (%)) is preferably 50 to 100%, more preferably 80 to 100%, and more preferably 85 to 100%. Is more preferable.
The alkyl group or fluorinated alkyl group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom other than a fluorine atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group or a tert-butoxy group. Group and ethoxy group are particularly preferred.
Examples of the halogen atom as the substituent include a chlorine atom, a bromine atom, and an iodine atom.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
Preferred specific examples of the anion portion (3) are listed below.

［式中、Ｒ^７”は置換基であり、ｗ１１〜ｗ１６はそれぞれ独立に０〜３の整数であり、ｖ１１〜ｖ１８はそれぞれ独立に０〜３の整数であり、ｕは０〜４の整数であり、ｍ１１〜ｍ１２はそれぞれ独立に０または１であり、ｇは１〜４の整数であり、ｔは３〜２０の整数である。］

[Wherein R ⁷ ″ is a substituent, w11 to w16 are each independently an integer of 0 to 3, v11 to v18 are each independently an integer of 0 to 3, and u is an integer of 0 to 4. M11 to m12 are each independently 0 or 1, g is an integer of 1 to 4, and t is an integer of 3 to 20.]

Wherein (3a) ~ (3j), " as the substituent of the formula (11a-1) ~ ^{R 7} in (11a-3) in" ^{R 7} include the same.
When the code | symbol (w11-w16) attached | subjected to R < ⁷ >'' is an integer greater than or equal to 2, several R < ⁷ >'' in the said compound may be the same respectively, and may differ.
w11 to w16 are each independently an integer of 0 to 3, preferably 0 or 1, and most preferably 0.
v11 to v18 are each independently 0 to 3, and preferably 0 or 1.
u is each independently an integer of 0 to 4, preferably 0 to 2.
g is each independently an integer of 1 to 4, preferably 1 or 2, and most preferably 1.
t is an integer of 3 to 20, more preferably 3 to 15, and still more preferably 3 to 12.

[Cation part of component (B1)]
In the formulas (1) to (3), A ⁺ is a counter cation.
A ⁺ is not particularly limited, and any one that has been proposed as a cation part of an acid generator for a chemically amplified resist can be used.
As a suitable cation part, the cation part of onium salt type acid generators, such as an iodonium salt and a sulfonium salt, is mentioned, for example. Examples of the cation moiety include cations represented by the following general formula (b-1 ′) or (b-2 ′).

［式（ｂ−１’）中、Ｒ^１”〜Ｒ^３”は、それぞれ独立に、置換基を有していてもよいアリール基またはアルキル基を表し、Ｒ^１”〜Ｒ^３”のうちのいずれか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す。式（ｂ−２’）中、Ｒ^５”〜Ｒ^６”は、それぞれ独立に、置換基を有していてもよいアリール基またはアルキル基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[In formula (b-1 ′), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent, and R ¹ ″ to R ³ ″ Any two of them may be bonded to each other to form a ring together with the sulfur atom in the formula, and at least one of R ¹ ″ to R ³ ″ represents an aryl group. In formula (b-2 ′), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group which may have a substituent, and at least one of R ⁵ ″ to R ⁶ ″ Represents an aryl group. ]

In formula (b-1 ′), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent.
Any two of R ¹ ″ to R ³ ″ 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 of R ¹ ″ to R ³ ″ are aryl groups.

The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and examples thereof include an aryl group having 6 to 20 carbon atoms. 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.
The aryl group may have a substituent. “Having a substituent” means that part or all of the hydrogen atoms of the aryl group are substituted with a substituent, and examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, An alkoxyalkyloxy group, —O—R ⁵⁰ —C (═O) — (O) _m —R ⁵¹ [wherein R ⁵⁰ is an alkylene group or a single bond, and R ⁵¹ is an acid-dissociable group or an acid non-dissociation group. And m is 0 or 1. ] Etc. are mentioned.
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, ethyl group, propyl group, n-butyl group, or tert-butyl group. Is most preferred.
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 preferable, and a methoxy group and an ethoxy group are most preferable.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.

Examples of the alkoxyalkyloxy group in which the hydrogen atom of the aryl group may be substituted include, for example, —O—C (R ⁴⁷ ) (R ⁴⁸ ) —O—R ^{49 wherein} R ⁴⁷ and R ⁴⁸ are each It is independently a hydrogen atom or a linear or branched alkyl group, R ⁴⁹ is an alkyl group, and R ⁴⁸ and R ⁴⁹ may be bonded to each other to form one ring structure. However, at least one of R ⁴⁷ and R ⁴⁸ is a hydrogen atom. ].
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms, preferably an ethyl group or a methyl group, and most preferably a methyl group.
One of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom, the other is preferably a hydrogen atom or a methyl group, and both R ⁴⁷ and R ⁴⁸ are particularly preferably hydrogen atoms.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms and may be linear, branched or cyclic.
The linear or branched alkyl group for R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. Can be mentioned.
The cyclic alkyl group for R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms.
Specifically, monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group, etc. And a group obtained by removing one or more hydrogen atoms from the polycycloalkane. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
R ⁴⁸ and R ⁴⁹ may be bonded to each other to form one ring structure. In this case, a cyclic group is formed by R ⁴⁸ , R ⁴⁹ , the oxygen atom to which R ⁴⁹ is bonded, and the carbon atom to which the oxygen atom and R ⁴⁸ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring.

In —O—R ⁵⁰ —C (═O) — (O) _m —R ⁵¹ in which the hydrogen atom of the aryl group may be substituted, the alkylene group for R ⁵⁰ is a linear or branched alkylene Group is preferable, and the number of carbon atoms is preferably 1 to 5. Examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a 1,1-dimethylethylene group.
The acid dissociable group in R ⁵¹ is not particularly limited as long as it is an organic group that can be dissociated by the action of an acid (acid generated from the component (B) during exposure). For example, in the component (A), the structural unit ( Examples thereof include the same acid dissociable, dissolution inhibiting groups as described in the description of a1). Among them, the tertiary alkyl ester type is preferable.
Examples of the acid non-dissociable group in R ⁵¹ include a hydrocarbon group having 3 to 30 carbon atoms which does not correspond to the acid dissociable group and may have a substituent. Examples of the hydrocarbon group, for example, include the same ones as exemplified in the description of X ¹⁰ in the formula (1).
The hydrocarbon group is preferably an aliphatic hydrocarbon group, and may be a linear or branched saturated hydrocarbon group, an aliphatic cyclic group which may have a substituent, or an aliphatic cyclic group. A group in which a linear or branched saturated hydrocarbon group is bonded is more preferable.
The aliphatic cyclic group which may have a substituent includes a hetero atom in the ring structure such as the groups represented by the formulas (L1) to (L5) and (S1) to (S4). An aliphatic cyclic group containing a substituent is preferred.
The group in which a linear or branched saturated hydrocarbon group is bonded to an aliphatic cyclic group includes a group in which a linear alkylene group is bonded to a carbon atom constituting the ring structure of the aliphatic cyclic group. preferable. As the linear alkylene group, a methylene group is particularly preferable.

In formula (b-1 ′), the alkyl group of R ¹ ″ to R ³ ″ is not particularly limited, and examples thereof include linear, branched or cyclic alkyl groups 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 decyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
The alkyl group may have a substituent. “Having a substituent” means that part or all of the hydrogen atoms of the alkyl group are substituted with a substituent, and the substituent may be a substituent that the aryl group may have. The thing similar to what was mentioned as group is mentioned.

In formula (b-1 ′), any two of R ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula. The ring may be saturated or unsaturated. The ring may be monocyclic or polycyclic. For example, when one or both of two forming a ring is a cyclic group (cyclic alkyl group or aryl group), a polycyclic ring (fused ring) is formed when they are combined.
When two of R ¹ ″ to R ³ ″ are combined to form a ring, one ring containing a sulfur atom in the ring skeleton in the formula is a 3 to 10 membered ring including the sulfur atom. Of these, a 5- to 7-membered ring is particularly preferable.
Specific examples of the ring formed by combining two of R ¹ ″ to R ³ ″ include benzothiophene, dibenzothiophene, 9H-thioxanthene, thioxanthone, thianthrene, phenoxathiin, tetrahydrothiophenium, tetrahydro Examples include thiopyranium.
When any two of R ¹ ″ to R ³ ″ 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.

Of the cation moiety of the compound represented by formula (b-1), when R ¹ ″ to R ³ ″ are all phenyl groups that may have a substituent, that is, the cation moiety is triphenylsulfonium. Preferable specific examples in the case of having a skeleton include, for example, cations represented by the following formulas (I-1-1) to (I-1-17).

Moreover, what substituted a part or all of the phenyl group in these cation parts with the naphthyl group which may have a substituent is mentioned as a preferable thing. Of the three phenyl groups, one or two are preferably substituted with a naphthyl group.
Further, among the cation moieties of the compound represented by the formula (b-1 ′), any two of R ¹ ″ to R ³ ″ are bonded to each other to form a ring together with the sulfur atom in the formula. Preferable specific examples in the case of being present include, for example, cation moieties represented by the following formulas (I-2-1) to (I-2-4).

［式中、Ｒ^９は、置換基を有していてもよいフェニル基、置換基を有していてもよいナフチル基または炭素数１〜５のアルキル基であり、Ｒ^１０は、置換基を有していてもよいフェニル基、置換基を有していてもよいナフチル基、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水酸基であり、ｕは１〜３の整数である。］

[Wherein, R ⁹ is a phenyl group which may have a substituent, a naphthyl group which may have a substituent or an alkyl group having 1 to 5 carbon atoms, and R ¹⁰ represents a substituent. A phenyl group which may have, a naphthyl group which may have a substituent, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms or a hydroxyl group, u is an integer of 1 to 3 It is. ]

［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 formulas (I-2-1) to (I-2-2), in R ^{9 to} R ¹⁰ , the substituents that the phenyl group or naphthyl group may have include R ¹ ″ to R ³ ″. The thing similar to what was mentioned as a substituent which an aryl group may have is mentioned. As the substituent that the alkyl group have the ^{R 9 ~R 10, R 1 "} ~R 3" are the same as those of the substituent which may be alkyl groups have in the Can be mentioned.
u is an integer of 1 to 3, and 1 or 2 is most preferable.
In formulas (I-2-3) to (I-2-4), in R ^{41 to} R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and in particular, a linear or branched alkyl group A group is more preferable, and a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-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.

In formula (b-2 ′), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group which may have a substituent.
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 ″.
In formula (b-2 ′), at least one of R ⁵ ″ to R ⁶ ″ is an aryl group, and all of R ⁵ ″ to R ⁶ ″ are preferably aryl groups. Among them, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.

As the component (B1), one type may be used alone, or two or more types may be used in combination.
Among the above, A ⁺ is preferably a cation represented by the formula (b-1 ′), among which a cation represented by the formulas (I-1-1) to (I-1-17) A cation having a triphenyl skeleton is preferred.
Component (B1) is, for example, US Patent Application Publication No. 2009/0130597, JP 2009-91350 A, JP 2009-186852 A, JP 2009-167156 A, JP 2009-209128 A. , Etc. can be synthesized using a known method.

[(B2) component]
The component (B2) is a compound represented by the following general formula (4).
Hereinafter, the anion portion of the compound represented by the general formula (4) will be described as the anion portion (4).

［式（４）中、Ｒ^０は置換基を有していてもよい炭素数１〜１２の炭化水素基である。ただし、−ＳＯ_３ ⁻における硫黄原子に隣接する炭素原子にはフッ素原子は結合していない。Ａｂ^＋は芳香族基を有する対カチオンである。］

[In Formula (4), ^R0 is a C1-C12 hydrocarbon group which may have a substituent. However, the fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in —SO ₃ ^— . Ab ⁺ is a counter cation having an aromatic group. ]

{Anion part (4)}
In the formula (4), the hydrocarbon group for R ⁰ may or may not have a substituent.
However, the fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in —SO ₃ ^— . For this reason, the component (B2) generates a sulfonic acid having a weak acid strength by exposure as compared with, for example, a fluorine atom bonded to a carbon atom adjacent to a sulfur atom in —SO ₃ ^— . In the present invention, the resist pattern shape becomes better. It also contributes to the improvement of lithography properties.
The substituent preferably does not contain a fluorine atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms and an oxygen atom (= O). The carbon atom in the substituent is not included in the carbon number of the hydrocarbon group in R ⁰ .

The hydrocarbon group having 1 to 12 carbon atoms in R ⁰ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. By being a hydrocarbon group having 1 to 12 carbon atoms, the rectangularity of the resist pattern is improved.

When the hydrocarbon group in R ⁰ is an aliphatic hydrocarbon group, the aliphatic hydrocarbon group may be either saturated or unsaturated, and is usually preferably saturated.
In addition, the aliphatic hydrocarbon group may be a chain (straight chain or branched chain) or may be cyclic.
As the chain aliphatic hydrocarbon group, a linear or branched alkyl group is preferable, and the alkyl group preferably has 1 to 10 carbon atoms and has 1 to 8 carbon atoms. Is more preferable, and it is further more preferable that it is 3-8.
Specific examples of linear or branched alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl. Group, n-hexyl group, n-heptyl group, n-octyl group and the like. Among these, a methyl group, an n-propyl group, an n-butyl group, and an n-octyl group are preferable, and an n-octyl group is particularly preferable.

As a specific example of the sulfonate ion in which R ⁰ is a linear or branched alkyl group as the anion part of the component (B2), for example, an anion represented by the following general formula (4-1) is preferable. It is mentioned as a thing.

［式中、ａは１〜１０の整数である。］

[Wherein, a is an integer of 1 to 10. ]

In said formula (4-1), a is an integer of 1-10, Preferably it is an integer of 1-8.
Specific examples of the sulfonate ion represented by the general formula (4-1) include methanesulfonate ion, ethanesulfonate ion, n-propanesulfonate ion, n-butanesulfonate ion, n-octanesulfonate ion, and the like. It is done.

In the hydrocarbon group of R ⁰ , the cyclic hydrocarbon group is an aliphatic cyclic group or a group in which at least one hydrogen atom of a chain hydrocarbon group is substituted with an aliphatic cyclic group (aliphatic ring). Formula group-containing group) and the like.
Examples of the “aliphatic cyclic group” include the same groups as those described as the “aliphatic cyclic group” in the acid dissociable, dissolution inhibiting group of the component (A), which has 3 to 12 carbon atoms. It is preferable that the number of carbon atoms is 4-10.
The aliphatic cyclic group may be a polycyclic group or a monocyclic group.
The monocyclic group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane having 3 to 6 carbon atoms, and examples thereof include a cyclopentyl group and a cyclohexyl group.
The polycyclic group preferably has 7 to 12 carbon atoms, and specific examples include an adamantyl group, norbornyl group, isobornyl group, tricyclodecyl group, and tetracyclododecyl group.
Among these, a polycyclic group is preferable, and an adamantyl group, a norbornyl group, and a tetracyclododecyl group are preferable industrially. Further, as described above, these aliphatic cyclic groups may or may not have a substituent.
Examples of the aliphatic cyclic group in the “aliphatic cyclic group-containing group” include the same as those described above. In the “aliphatic cyclic group-containing group”, the chain hydrocarbon group to which the aliphatic cyclic group is bonded is preferably a linear or branched alkyl group, and preferably an alkyl group having 1 to 5 carbon atoms. , Methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like. Among these, a linear alkyl group is Industrially, a methyl group or an ethyl group is preferable.

Specific examples of the sulfonate ion in which R ⁰ is a cyclic aliphatic hydrocarbon group as the anion part of the component (B2) include, for example, an anion represented by the following general formula (4-2). It is done.

［式中、Ｘ^４０は置換基として酸素原子（＝Ｏ）を有していてもよい炭素数４〜１２の環状のアルキル基であり、ｒは０または１である。］

[Wherein, X ⁴⁰ is a cyclic alkyl group having 4 to 12 carbon atoms which may have an oxygen atom (═O) as a substituent, and r is 0 or 1. ]

In the general formula (4-2), X ⁴⁰ represents a cyclic alkyl group having 4 to 12 carbon atoms which may have an oxygen atom (═O) as a substituent.
“It may have 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 12 carbon atoms are oxygen atoms ( = O) may be substituted.
The cyclic alkyl group for X ⁴⁰ is not particularly limited as long as it has 4 to 12 carbon atoms, and may be any of a polycyclic group and a monocyclic group. For example, monocycloalkane, bicycloalkane, tricycloalkane And groups obtained by removing one hydrogen atom from a polycycloalkane such as tetracycloalkane. As the monocyclic group, a group in which one hydrogen atom is removed from a monocycloalkane having 3 to 8 carbon atoms is preferable, and specific examples include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and the like. it can. The polycyclic group preferably has 7 to 12 carbon atoms, and specific examples include an adamantyl group, norbornyl group, isobornyl group, tricyclodecyl group, and tetracyclododecyl group.
X ⁴⁰ is preferably a polycyclic alkyl group having 4 to 12 carbon atoms having an oxygen atom (═O) as a substituent, and industrially one of 1 constituting an adamantyl group, norbornyl group, or tetracyclododecyl group A group in which two hydrogen atoms bonded to a carbon atom are substituted with an oxygen atom (═O) is preferred, and a norbornyl group having an oxygen atom (═O) as a substituent is particularly preferred.

X ⁴⁰ may have a substituent other than an oxygen atom. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms.

  In the general formula (4-2), r represents 0 or 1, and is preferably 1.

  Specific examples of the anion represented by the general formula (4-2) include, for example, the following formulas (4-2-1) to (4-2-5) and formulas (4-2-11) to (4). -2-12).

When the hydrocarbon group in R ⁰ is an aromatic hydrocarbon group, examples of the aromatic hydrocarbon group include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a phenethyl group, and a naphthyl group. As described above, the aromatic hydrocarbon group may or may not have a substituent.
Specific examples of when R ⁰ is an aromatic hydrocarbon group include a group represented by the following formula (4-3-1) or (4-3-2).

In formula (4-3-1), R ⁶¹ and R ⁶² are each independently an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.
^Examples of the alkyl group of R ⁶¹ and R ⁶² include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. A methyl group is preferred.
^Examples of the alkoxy group of R ⁶¹ and R ⁶² include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a tert-butoxy group and the like, and a methoxy group and an ethoxy group are particularly preferable.
d ′ and e ′ are each independently an integer of 0 to 4, preferably 0 to 2, and most preferably 0.
d 'and / or e' is an integer of 2 or ^{more, if R 61} and / or ^{R 62} there are a plurality, a plurality of ^{R 61} and / or ^{R 62} is different may be the same as each other Also good.

In formula (4-3-2), R ⁶³ represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.
^Examples of the alkyl group of R ⁶³ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. preferable.
^Examples of the alkoxy group for R ⁶³ include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, and a tert-butoxy group, and a methoxy group and an ethoxy group are particularly preferable.
f ′ is an integer of 0 to 3, preferably 1 or 2, and most preferably 1.
A f 'is an integer of 2 or more, if R ⁶³ there are a plurality, a plurality of R ⁶³ may be different may be the same as each other.
Specific examples of the sulfonate ion represented by the general formula (4-3-2) include benzene sulfonate and p-toluene sulfonate.

{Cation part of component (B2)}
In the formula (4), Ab ⁺ is a counter cation having an aromatic group, and contains an aromatic ring among the A ⁺ in the above formulas (1) to (3) (cation part of the component (B1)). It is the same as what you do. Among them, the cation represented by the above formulas (I-1-1) to (I-1-17), (I-2-3) or (I-2-4) is more preferable, and the formula (I- The cations represented by 1-1) to (I-1-17) are particularly preferable.

  Among the above, the component (B2) is preferably composed of a compound represented by the following general formula (b2-1).

［式中、Ｘ^４０は置換基として酸素原子（＝Ｏ）を有していてもよい炭素数４〜１２の環状のアルキル基であり、ｒは０または１であり、Ａｂ^＋は芳香族基を有する対カチオンである。］

[Wherein, X ⁴⁰ is a cyclic alkyl group having 4 to 12 carbon atoms which may have an oxygen atom (= O) as a substituent, r is 0 or 1, and Ab ⁺ is an aromatic group. Is a counter cation. ]

In the formula (b2-1), X ⁴⁰ , r and Ab ⁺ are the same as described above.
As the component (B2), a compound represented by general formula (b2-1-10) shown below is particularly preferable.

［式中、Ｒ^０Ｘは置換基として酸素原子（＝Ｏ）を有する炭素数４〜１２の環状のアルキル基を表し；ｒ、Ｒ^１”〜Ｒ^３”はそれぞれ上記と同じである。］

[Wherein R ^0X represents a cyclic alkyl group having 4 to 12 carbon atoms having an oxygen atom (═O) as a substituent; and r and R ¹ ″ to R ³ ″ are the same as defined above. ]

In the formula (b2-1-10), R ^0X represents a C 4-12 cyclic alkyl group having an oxygen atom (═O) as a substituent.
Examples of R ^0X include those in which two hydrogen atoms bonded to one carbon atom constituting the cyclic alkyl group of X ⁴⁰ are replaced with oxygen atoms (═O).

Below, the suitable specific example of (B2) component is shown.

  As the component (B2), one type may be used alone, or two or more types may be used in combination.

In the positive resist composition of the present invention, the content of the component (B1) is 4 to 30 parts by mass with respect to 100 parts by mass of the component (A), and the content of the component (B2) is (A). It is preferable that it is 0.1-4 mass parts with respect to 100 mass parts of components. When the contents of the component (B1) and the component (B2) are in the above ranges, the depth of focus (DOF) characteristics and the pattern shape are both better obtained.
When the content of the component (B1) is equal to or higher than the lower limit value, the depth of focus width (DOF) characteristic is further improved, and when it is equal to or lower than the upper limit value, sensitivity and lithography characteristics are improved.
When the content of the component (B2) is equal to or higher than the lower limit value, a good pattern shape is easily obtained, and when it is equal to or lower than the upper limit value, sensitivity and lithography characteristics are improved.
As for content of (B1) component, it is more preferable that it is 5-20 mass parts with respect to 100 mass parts of (A) component, and it is further more preferable that it is 8-15 mass parts.
The content of the component (B2) is more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the component (A), and 0.5 to 2 parts by mass is the pattern shape and resolution. This is more preferable because it is excellent in the balance between improvement of property and DOF.

[(B3) component]
In the positive resist composition of the present invention, as the component (B), an acid generator component that does not correspond to the above components (B1) and (B2), as necessary, within a range not impairing the effects of the present invention ( (Hereinafter referred to as “component (B3)”).
The component (B3) is not particularly limited as long as it does not correspond to the components (B1) and (B2), and various types of acid generators for chemically amplified resists have been proposed so far. Therefore, it can be used by appropriately selecting from them. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts (excluding the components (B1) and (B2)), oxime sulfonate acid generators, bis There are many known diazomethane acid generators such as alkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, nitrobenzyl sulfonate acid generators, iminosulfonate acid generators, disulfone acid generators, etc. ing.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) (however, represented by the general formula (1), (2) or (4)) Excluding compounds) can be used.

［式中、Ｒ^１”〜Ｒ^３”、Ｒ^５”〜Ｒ^６”はそれぞれ前記と同じであり、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 ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ are the same as defined above, and R ⁴ ″ represents an alkyl group which may have a substituent, a halogenated alkyl group, aryl Represents a group or an alkenyl group.]

Wherein ^{(b-1), R 1} "~R 3" are respectively similar to ^R 1 ^{"~R 3"} in the formula (b-1 ').
Wherein ^{(b-2), R 5} "~R 6" are respectively similar to the ^R 5 ^{"~R 6"} in general formula (b-2 ').
In the formulas (b-1) to (b-2), R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent (provided that the above general formula (Excluding the hydrocarbon group represented by R ⁰ in (4)).
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 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
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%. It is preferable that it is 50 to 100%, and 100% is the most preferable. The higher the halogenation rate, the more preferable the strength of the acid.
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.

The alkyl group, halogenated alkyl group, aryl group or alkenyl group in R ⁴ ″ may have a substituent.
“Optionally substituted” means that a part or all of hydrogen atoms in the alkyl group, halogenated alkyl group, aryl group or alkenyl group are substituents (other atoms or groups other than hydrogen atoms). It may be substituted with.
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, and XQ- [wherein X is a hydrocarbon group that may have a substituent, and Q is a divalent group including an oxygen atom. The linking group of ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described as the halogen atom and alkyl group in the halogenated alkyl group in R ⁴ ″.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

In the group represented by XQ-, X includes, for example, a hydrocarbon group having 1 to 30 carbon atoms. Of these, the hydrocarbon group having 3 to 30 carbon atoms, the same as X ¹⁰ in the formula (1) can be mentioned. Examples of the hydrocarbon group having 1 to 2 carbon atoms include a methyl group, an ethyl group, and a vinyl group.
Q is a divalent linking group containing an oxygen atom.
Q may consist only of oxygen atoms, or may contain atoms other than oxygen atoms. 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 ⁹⁰ —O—, —R ⁹¹ —O—C (═O) —, —O—R ⁹² —O—C (═O) —, —C (═O) —O. —R ⁹³ —, —C (═O) —O—R ⁹⁴ —O—, —C (═O) —O—R ⁹⁵ —O—C (═O) —, —R ⁹⁶ —C (═O) —O—R ⁹⁷ —O—, —R ⁹⁸ —C (═O) —O—R ⁹⁹ —O—C (═O) — wherein R ^{90 to} R ⁹⁹ are each independently an alkylene group. ] Etc. are mentioned.
The alkylene group for R ⁹⁰ to R ^99, in the formula (1) for ^{Q 1} in the ^description, include the same as those of the alkylene group for R 91 ^{to R 99.}

R ⁴ ″ is preferably an unsubstituted alkyl group or a fluorinated alkyl group, or an alkyl group or a fluorinated alkyl group having a group represented by XQ— as a substituent.
In this case, R ⁴ ″ is Z—Y ¹ — [wherein Z is a hydrogen atom or a group represented by XQ— (wherein X and Q are as defined above), Y ¹ is an alkylene group having 1 to 4 carbon atoms which may have a substituent or a fluorinated alkylene group having 1 to 4 carbon atoms which may have a substituent. It is preferable.
X-Q-Y 1 ^- In the group represented by alkylene groups of Y ^1, a fluorinated alkylene group, respectively, alkylene groups exemplified in the description of Q ³ in the general formula (3), a fluorinated alkylene group Among these, it is the same as that of C1-C4.
Y ¹ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the sulfur atom in adjacent SO ₃ ^— 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. 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.

  Specific examples of the compound represented by the formula (b-1) or (b-2) include, for example, diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate; bis (4-tert-butylphenyl) iodonium trifluoromethane. Sulfonate or nonafluorobutane sulfonate; Triphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; Tri (4-methylphenyl) sulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane Sulfonate; Trimethylmethanesulfonate of dimethyl (4-hydroxynaphthyl) sulfonium, its heptaful Lopropane sulfonate or its nonafluorobutane sulfonate; trifluoromethane sulfonate of monophenyldimethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; trifluoromethane sulfonate of diphenyl monomethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate (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 heptafluoropropane sulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate; trifluoromethane sulfonate of di (1-naphthyl) phenylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1-phenyltetrahydrothiophenium trifluoromethane sulfonate, 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.

Further, as the onium salt acid generator, the anion moiety (R ⁴ ″ SO ₃ ⁻ ) in the general formula (b-1) or (b-2) is changed to the following general formula (b-3) or (b-4). ) Can also be used (excluding the compound represented by the general formula (3)) (the cation moiety is represented by the formula (b-1) or (b-2)). Same as the cation part in the inside).

［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、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１〜１０のアルキル基を表す。］

[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 represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

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.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably Has 1 to 7 carbon atoms, more preferably 1 to 3 carbon atoms.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid increases, and high-energy light or electron beam of 200 nm or less The ratio of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all. Are a perfluoroalkylene group or a perfluoroalkyl group in which a hydrogen atom is substituted with a fluorine atom.

Further, as the onium salt-based acid generator, the anion moiety (R ⁴ ″ SO ₃ ⁻ ) in the general formula (b-1) or (b-2) is R ⁸ ″ —COO ⁻ [wherein R ⁸ ″ Is an alkyl group or a fluorinated alkyl group which may have a substituent.] (The cation moiety is the same as (b-1) or (b-2)).
As R ⁸ ″, the same as R ⁴ ″ can be mentioned.
Specific examples of the “R ⁸ ” —COO ⁻ ”include trifluoroacetate ions, acetate ions, 1-adamantane carboxylate ions, and the like.

  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 for 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 having no substituent as R ³⁵ described above.
p ″ is preferably 2.

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

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

  As the component (B3), one type of acid generator may be used alone, or two or more types may be used in combination.

  The content of the component (B) in the positive resist composition of the present invention is preferably 1 to 70 parts by weight, more preferably 5 to 60 parts by weight, and 7 to 50 parts by weight with respect to 100 parts by weight of the component (A). Is most preferred. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

Moreover, since the content rate of (B1) component in (B) component is excellent in the improvement effect of DOF, it is preferable that it is 40 mass% or more, it is more preferable that it is 50-100 mass%, and 70- More preferably, it is 100 mass%.
Moreover, since the content rate of (B2) component in (B) component is excellent in the improvement effect of a pattern shape, it is preferable that it is 4 mass% or more, and it is more preferable that it is 4-20 mass%. More preferably, it is -12 mass%.

<Optional component>
The positive resist composition of the present invention may contain a nitrogen-containing organic compound (D) (excluding the resin component (A1); hereinafter referred to as the component (D)) as an optional component.
The component (D) is not particularly limited as long as it acts as an acid diffusion control agent, that is, a quencher that traps the acid generated from the component (B) by exposure, and a wide variety of components have been proposed. Therefore, any known one may be used.
As the component (D), a low molecular compound (non-polymer) is usually used. Examples of the component (D) include amines such as aliphatic amines and aromatic amines, and aliphatic amines are preferable, and 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 , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol 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.
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.
Examples of the aromatic amine include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, 2,2 Examples include '-dibilidyl, 4,4'-dibilidyl 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.

The positive resist composition of the present invention includes, as optional components, organic carboxylic acids, phosphorus oxoacids and derivatives thereof for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, retention stability over time, etc. At least one compound (E) selected from the group consisting of (hereinafter referred to as component (E)) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of 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.
(E) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

  The positive resist composition of the present invention further contains miscible additives as desired, for example, additional resins for improving the performance of the resist film, surfactants for improving coating properties, dissolution inhibitors, Plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be added and contained as appropriate.

The positive resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, 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 or dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or the compound having an ester bond Ethers such as ether, monopropyl ether, monobutyl ether and other monoalkyl ethers and monophenyl ether Derivatives of polyhydric alcohols such as compounds having a combination [in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; 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 , Dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. Examples of the solvent include dimethyl sulfoxide (DMSO).
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Of these, PGMEA, PGME, γ-butyrolactone, and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL 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.
The amount of component (S) used is not particularly limited, and is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. Generally, the resist composition is used so that the solid content concentration is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

≪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 positive resist composition of the present invention, a step of exposing the resist film, and developing the resist film to form a resist. Forming a pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition is coated on a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. For example, an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus is used for exposure through a mask (mask pattern) on which a predetermined pattern is formed, or an electron beam that does not pass through the mask pattern. After selective exposure by direct irradiation or the like, PEB (post-exposure heating) is applied for 40 to 120 seconds, preferably 60 to 90 seconds under a temperature condition of 80 to 150 ° C. Subsequently, this is developed using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH), preferably rinsed with pure water and dried. In some cases, a baking process (post-bake) may be performed after the development process.
In this way, a resist pattern faithful to the mask pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include organic films such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the resist pattern formed on the upper resist film is used as a mask. This is a method of patterning a lower organic film, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
In the multilayer resist method, basically, a method of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower organic film And a method of forming a multilayer structure of three or more layers (metal thin film etc.) (three-layer resist method).

The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV, and is particularly useful for ArF excimer laser.

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.

According to the positive resist composition of the present invention, it is possible to obtain an effect that a pattern having an excellent depth of focus (DOF) characteristic and a good shape can be formed.
“DOF” is a focal depth range in which a resist pattern can be formed with a dimension within which a deviation with respect to a target dimension is within a predetermined range when the focus is shifted up and down with the same exposure amount. Larger values are preferred.

The reason why the above effect is obtained is not clear, but the excellent DOF characteristics are
[1] (A1) component to have a structure that _{-W-OSO 2} NH 2 in the side chain, the affinity between polymers is improved by hydrogen bonding, increasing the glass transition temperature (Tg) of the resist with it [2] Generated from the component (B1) during post-exposure baking by improving the heat resistance of the film, and [2] the polarity of the anion moiety of the component (B1) is high and the affinity with the component (A1) is high. This is probably because the acid diffusion length is shortened. In particular, with regard to [1], it is considered that the acid is physically short-diffused by suppressing the decrease in the hardness of the resist film during post-exposure baking by improving the heat resistance of the resist film.

Moreover, it is estimated as follows that it is excellent in a DOF characteristic and can form a pattern of a favorable shape.
During exposure in resist pattern formation, it is considered that the amount of acid generated from the component (B) increases as the intensity of light increases in the exposed area. Here, the portion where the light intensity is maximum is considered to be the center of the exposed portion. For example, in the case of a line-and-space resist pattern (hereinafter referred to as “LS pattern”), the center portion of the space between the lines, the hole In the case of this resist pattern, it is presumed that it is the center of the hole. In the case where the diffusion of the acid in the exposed portion is not controlled, the side wall of the unexposed portion having the same height as the central portion is easily dissolved by alkali development because the acid diffuses to the unexposed portion. As a result, it becomes easy to form a resist pattern having a shape in which the unexposed portion is partially dissolved.
In the present invention, since the component (B1) and the component (B2) are used in combination, salt exchange occurs particularly between the (B2) component in the unexposed area and the acid generated from the component (B1). . Then, the acid generated from the component (B1) upon exposure suppresses dissociation of the acid dissociable, dissolution inhibiting group in the (A1) component of the unexposed portion (a quenching effect due to salt exchange is exhibited). As a result, even if the intensity of light is maximum at the central portion, the acid dissociation reaction of the component (A1) in the entire space or hole proceeds more uniformly, so that a highly rectangular shape can be obtained. Is done.
Further, in the exposed portion, the component (B2) has no fluorine atom bonded to the carbon atom adjacent to the sulfur atom in —SO ₃ ^{—, and} therefore compared to the sulfonic acid generated from the component (B1) by exposure. Generates sulfonic acid with weak acid strength. As a result, the acid dissociable, dissolution inhibiting group in the (A1) component in the unexposed area is less likely to dissociate than when a strong acid is generated.

  As described above, in the positive resist composition of the present invention in which the (A1) component, the (B1) component, and the (B2) component are combined, the acid generated in the exposed portion within the resist film is exposed to the unexposed portion. Diffusion is remarkably suppressed, and the acid dissociation reaction of the component (A1) is also averaged over the entire exposed area, so that a good contrast between the exposed area and the unexposed area can be obtained, and the depth of focus is widened. It is considered that a resist pattern having a good shape can be formed.

  Further, according to the resist composition of the present invention, a resist pattern having high roundness can be formed, for example, in forming a hole pattern. In addition, it is possible to form a well-shaped hole pattern without band-like white irregularities on the circumferential portion of the hole. Further, the uniformity (CDU) of the hole diameter (CD) is improved, and a resist pattern having a good shape with high roundness can be formed even with a narrow pitch.

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 (m1-1) is referred to as “compound (m1-1)”, and the same applies to compounds represented by other formulas.

Monomers (compounds (m1-1), (m1-2), (m2-1), (m3-1), (m0-1)) used in polymer synthesis examples described below are shown below.
Of these, the compounds (m0-1) and (m2-1) were synthesized in monomer synthesis examples 1 and 2, which will be described later. The compound (m1-1) was synthesized in the same manner as in Synthesis Examples 1 and 2 described in JP2009-223300A.
In the analysis by NMR, the internal standard of ¹ H-NMR and the internal standard of ¹³ C-NMR is tetramethylsilane (TMS). The internal standard of ¹⁹ F-NMR is hexafluorobenzene (however, the peak of hexafluorobenzene was set to −160 ppm).

[Monomer Synthesis Example 1: Synthesis of Compound (m0-1) (3-sulfamoyloxyadamantyl methacrylate)]
A 5-L four-necked flask equipped with a thermometer, a dropping funnel and a stirrer was charged with nitrogen, and 980 g of heptane and 334 g (2.4 mol) of chlorosulfonyl isocyanate were charged from the dropping funnel. After cooling internal temperature to 5 degreeC, 110 g (2.4 mol) of formic acid was dripped from the dropping funnel at the speed | rate which can maintain internal temperature 5-8 degreeC. After completion of dropping, the internal temperature was raised to 20 ° C. and stirred for 10 hours. A solution of 186.7 g (0.79 mol) of 3-hydroxyadamantyl methacrylate, 525 g of N-methylpyrrolidone, 2.1 g of 4-methoxyphenol and 2.1 g of phenothiazine was added to the reaction mixture from an addition funnel at an internal temperature of 20 ° C. It dropped at the speed which can maintain the following. After stirring at an internal temperature of 20 to 25 ° C. for 3 hours, the reaction mixture was transferred to a separatory funnel and the upper layer was discarded. To the obtained lower layer, 890 g of ethyl acetate and 700 g of water were added, stirred and allowed to stand. Thereafter, liquid separation was performed, and an ethyl acetate layer and an aqueous layer were extracted. 890 g of ethyl acetate was added to the aqueous layer and re-extracted. Two ethyl acetate layers were mixed and then washed five times with 900 g of water. Subsequently, it was washed with 400 g of 7% by mass-aqueous sodium hydrogen carbonate solution and 400 g of water. After the washing, the organic layer was concentrated under reduced pressure to 500 g, and then 630 g of toluene was added. After heating to an internal temperature of 55 ° C., the mixture was cooled to 3 ° C. and recrystallized. The suspension obtained by the recrystallization operation was filtered to obtain 159.5 g (0.51 mol) of the target compound (m0-1) as crystals (yield = 64%).
The ¹ H-NMR analysis result of the obtained compound is shown below.
¹ H-NMR (300 MHz, solvent: deuterated dimethyl sulfoxide (DMSO-d ₆ )): δ (ppm) = 7.43 (2H, s), 5.96 (1H, s), 5.62 (1H, s ), 2.48 (2H, s), 2.35 (3H, br), 2.23 (1H, s), 2.04 (6H, m), 1.84 (3H, s) 1.52 ( 2H, s).

[Monomer Synthesis Example 2: Synthesis of Compound (m2-1)]
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 the target compound (m2-1).
The instrumental analysis results of the obtained compound were as follows.
¹ H-NMR (400 MHz, solvent: CDCl ₃ ): 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).

[Polymer Synthesis Example 1 (Synthesis of Polymer Compound 1)]
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 30.00 g (94.94 mmol) of the compound (m2-1) and 3.39 g (17.29 mmol) of the compound (m1-2) 6.34 g (20.12 mmol) of the compound (m0-1) was dissolved in 78.50 g of methyl ethyl ketone (MEK). To this solution, 13.60 mmol of dimethyl azobisisobutyrate (V-601) was added and dissolved as a polymerization initiator. This was dropwise added to a solution in which 39.57 g (151.05 mmol) of the compound (m1-1) was dissolved in 39.57 g of MEK and heated to 80 ° C. in a nitrogen atmosphere over 3 hours. After completion of dropping, the reaction solution was heated and stirred for 2 hours, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization solution was dropped into a large amount of a mixed solvent of n-heptane / isopropyl alcohol to perform polymer precipitation, and the precipitated white powder was filtered off, washed with methanol and MEK, and dried. As a result, 53.6 g of the target polymer compound 1 was obtained.
The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement for this polymer compound was 7,600, and the molecular weight dispersity (Mw / Mn) was 1.80. 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 1 / m / n / o = 44 / It was 41/6/9.

[Polymer Synthesis Example 2 (Synthesis of Polymer Compound 2)]
In the same manner as in Polymer Synthesis Example 1 except that an equimolar amount of Compound (m3-1) was used in place of Compound (m0-1) in Polymer Synthesis Example 1, polymer compound 2 which was the target product Got.
About this high molecular compound, the mass mean molecular weight (Mw) of standard polystyrene conversion calculated | required by GPC measurement was 9000, and molecular weight dispersion degree (Mw / Mn) was 1.62. Further, the copolymer composition ratio (ratio (molar ratio) of each structural unit in the following structural formula) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n / o = 45. / 40/5/10.

[(B) Component Synthesis Example 1 (Synthesis of Compound (b1-1))]
Compound (b1-1) was synthesized in the same manner as Example 7 of US Patent Application Publication No. 2009/0130597, except that compound (b) synthesized by the following procedure was used instead of compound (e). did.
[Synthesis of Compound (b)]
Under a nitrogen atmosphere, compound (a) (8.2 g) and dichloromethane (82 g) were added to a three-necked flask and cooled to 5 ° C. or lower. N, N-dimethylaminopyridine (0.46 g) was added thereto and stirred at 5 ° C. or lower for 5 minutes, and then ethyl-N, N-dimethylaminopropylcarbodiimide (3.9 g) was added. Then, it stirred for 10 minutes and the compound (2a) (4.3g) was added. After the addition was completed, the temperature was raised to room temperature, and the mixture was stirred at room temperature for 15 hours. The organic phase was dropped into n-hexane (1000 g) and reprecipitated to obtain compound (b) (5.0 g).
The results of analyzing the obtained compound by NMR are shown below.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.82 (m, 10H, ArH), 7.59 (s, 2H, ArH), 4.55 (s, 2H) , CH ₂ ), 2.29 (m, 6H, CH ₃ ), 1.90-1.93 (m, 4H, OCCH ₂ + cyclopropyl), 1.48-1.75 (m, 6H, cyclopentyl), 0 _{.77-0.81 (t, 3H, CH 3} ).
From the results described above, it was confirmed that the compound (b) had a structure shown below.

<Example 1, Comparative Examples 1-2, Reference Example 1>
Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition.

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1: The polymer compound 1.
(A) -2: The polymer compound 2.
(B) -1: An acid generator comprising the compound (b1-1).
(B) -2: An acid generator composed of a compound represented by the following chemical formula (b2-1-20).

(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: γ-butyrolactone.
(S) -2: Mixed solvent of PGMEA / PGME = 6/4 (mass ratio).

About the obtained positive resist composition, a resist pattern was formed according to the following procedure, and the lithography characteristics were evaluated.
[Formation of resist pattern]
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. On the antireflection film, the positive resist composition prepared above is applied using a spinner, subjected to PAB treatment at 90 ° C. for 60 seconds on a hot plate, and dried to obtain a film thickness. A 100 nm resist film was formed.
Next, a protective film-forming coating solution “TILC-057” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied onto the resist film using a spinner and heated at 90 ° C. for 60 seconds. A top coat having a thickness of 35 nm was formed.
Next, an ArF excimer laser is applied to the resist film on which the top coat is formed through a mask by an ArF immersion exposure apparatus NSR-S609B (manufactured by Nikon; NA (numerical aperture) = 1.07, Annular). (193 nm) was irradiated. Thereafter, PEB treatment is performed at 85 ° C. for 60 seconds, and further, alkali development is performed at 23 ° C. with a 2.38 mass% TMAH aqueous solution NMD-3 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 seconds. Post-baking was carried out at 45 ° C. for 45 seconds.
As a result, in any of the examples, a contact hole pattern (hereinafter referred to as “Dense-H pattern”) in which holes with a hole diameter of 85 nm are arranged at equal intervals (pitch 140 nm) can be formed in the resist film.
Moreover, the optimal exposure amount Eop (mJ / cm < ² >) in this Dense-H pattern formation was calculated | required, respectively. The results are shown in Table 2.

[Evaluation of DOF]
At the optimum exposure amount Eop at which the Dense-H pattern is formed, the resist pattern is formed in the same manner as in [Formation of resist pattern] by appropriately shifting the focus up and down, and the Dense-H pattern has a target dimension of ± 3%. The depth of focus depth (unit: μm) that can be formed at a dimensional change rate within the range (82.45 to 87.55 nm) was determined, and DOF was evaluated according to the following criteria. The results are shown in Table 2.
○: The width of the focal depth was 0.3 (μm) or more.
(Triangle | delta): The width | variety of the depth of focus was less than 0.3 (micrometer).

[Evaluation of Circularity]
The Dense-H pattern formed by the above Eop is observed from above, and 25 holes in each Dense-H pattern are measured with a length measuring SEM (manufactured by Hitachi, Ltd., product name: S-9220). The distance in 24 directions from the center to the outer edge was measured, and the triple value (3σ) of the standard deviation (σ) calculated from the result was obtained, and the roundness was evaluated according to the following criteria. The results are shown in Table 2.
The 3σ obtained in this way means that the smaller the value, the higher the roundness of the hole.
○: The triple value (3σ) was less than 4.0.
Δ: The tripled value (3σ) was 4.0 or more.

[Evaluation of pattern shape]
A Dense-H pattern having a hole diameter of 85 nm and a pitch of 140 nm formed by the Eop was observed using a scanning electron microscope SEM, and the cross-sectional shape thereof was evaluated according to the following criteria. The results are shown in Table 2.
○ indicates that the hole shape is highly perpendicular, and Δ and × indicate that the pattern (unexposed portion) has a constricted shape in this order, and the hole shape is defective.

  From the results of Table 2, only the positive resist composition of Example 1 containing all of the components (A1), (B1), and (B2) in the present invention is excellent in the depth of focus (DOF) characteristics, In addition, it was confirmed that a good hole-shaped pattern having high roundness and high perpendicularity can be formed.

In order to improve DOF characteristics, it is considered that a shorter diffusion length of the acid generated from the component (B) is preferable. On the other hand, a longer diffusion length of the acid is considered preferable for improving the pattern shape. For this reason, trying to improve both characteristics at the same time usually results in a trade-off relationship.
As will be described later, the positive resist composition according to the present invention uses the component (B1) to shorten the diffusion length of the acid in the unexposed area and increase the diffusion length to some extent in the exposed area. Therefore, it is considered that both characteristics can be made well balanced.

<Test Example 1: Evaluation of relationship between film reduction amount, DOF, and pattern shape>
[Preparation of Resin Solution A] A mixed solvent of PGMEA / PGME (mass ratio: 6/4) was added to the polymer compound 1 to obtain a resin solution A having a resin concentration of 9% by mass.
[Preparation of Resin Solution A ′] A mixed solvent of PGMEA / PGME (mass ratio: 6/4) was added to the polymer compound 2 to obtain a resin solution A ′ having a resin concentration of 9 mass%.
[Preparation of resin solution B]: The following alkali-soluble resin (100 parts by mass) and the compound (b1-1) (13.5 parts by mass) were mixed with isobutanol (IBA) and PGMEA (mass ratio). : IBA / PGMEA = 95/5) to obtain a resin solution B having a resin concentration of 3% by mass.
Alkali-soluble resin: Resin represented by the following formula (I) (mass average molecular weight 5000, manufactured by Promerus). In the formula, the number on the lower right of () is the molar ratio.

  Using the obtained resin solutions A, A ′ and B, the influence of the component (A) on the acid diffusion length was evaluated by the following procedure.

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. Thereby, an organic antireflection film having a film thickness of 89 nm was formed.
By applying the resin solution A or the resin solution A ′ prepared above on the antireflection film using a spinner, performing PAB treatment at 90 ° C. for 60 seconds on a hot plate, and drying. A first resin film having a thickness of 300 nm was formed.
Next, the resin solution B prepared above was applied onto the first resin film using a spinner and heated at 90 ° C. for 60 seconds to form a second resin film having a thickness of 100 nm. .
Next, ArF excimer is applied to the second resin film without using a mask by an ArF immersion exposure apparatus NSR-S302A (manufactured by Nikon; NA / sigma = 0.60 / 0.75-conventional type). Laser (193 nm) was irradiated. Thereafter, PEB treatment was performed at 100 ° C. for 60 seconds, and further alkali development was performed at 23 ° C. with a 2.38 mass% TMAH aqueous solution NMD-3 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 seconds. Post-baking was performed at 60 ° C. for 60 seconds. Then, the film thickness of the 1st resin film in an exposure part was measured by Nanospec 6100A (made by Nanometrics), and the film | membrane reduction amount (300 nm-film thickness after post-baking) was calculated | required.

Repeat the above series of operations by changing the exposure dose. From the result, create a graph with the exposure dose (mJ / cm ² ) on the horizontal axis and the film loss (Thick Loss) (unit: Å) on the vertical axis. did. The results are shown in FIGS. FIG. 1 is a graph showing the results using the resin solution A, and FIG. 2 is a graph showing the results using the resin solution A ′.

In the above evaluation results, it is considered that the greater the amount of film reduction, the more the acid generated in the exposed portion of the second resin film diffused to the deep portion of the first resin film, that is, the longer the diffusion length. It is done. As shown in FIGS. 1-2, in the case of the resin solution A using the high molecular compound 1, there was little film loss compared with the case of the resin solution A 'using the high molecular compound 1'. From the results, it was suggested that the presence of —OSO ₂ NH ₂ as a polar group suppresses acid diffusion compared to the case of having —OH.

[Preparation of resin solutions B1 to B7]
As shown in Table 3, the alkali-soluble resin (100 parts by mass) represented by the above formula (I) and the component (B) or (D) were mixed with a mixed solvent (mass by mass) of isobutanol (IBA) and PGMEA. Ratio: IBA / PGMEA = 95/5) to obtain resin solutions B1 to B7 having a resin concentration of 3% by mass.

Each abbreviation in Table 3 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(B) -1: An acid generator comprising the compound (b1-1).
(B) -2: An acid generator composed of the compound represented by the chemical formula (b2-1-20).
(B) -3: An acid generator composed of a compound represented by the following chemical formula (B) -3.
(B) -4: An acid generator comprising a compound represented by the following chemical formula (B) -4.
(B) -5: An acid generator composed of a compound represented by the following chemical formula (B) -5.
(D) -1: tri-n-pentylamine.

Using the resin solution A and the resin solutions B1 to B7, the amount of film reduction was determined in the same procedure as described above, and the influence of the type of acid generator was evaluated.
Ranges changing the exposure amount in the range of 0~60mJ / cm ^2, from the result, the exposure amount (mJ / cm ²⁾ for the horizontal axis, film thickness loss (unit: Å) Create a graph ordinate The results of film loss were evaluated according to the following criteria.
In addition, all the deprotection reactions resulting from film reduction are caused by acids generated from the compound corresponding to the component (B1), and the compounds corresponding to the component (B2) do not directly contribute to the deprotection reaction. .
(Standard)
X: The amount of film decrease in the range of 0 to 60 mJ / cm ² is smaller than that in the case of the combination of resin solution A and resin solution B (FIG. 1).
○: The amount of change in film reduction in the range of 0 to 60 mJ / cm ² is larger than that in the case of the combination of resin solution A and resin solution B (FIG. 1).

This evaluation result shows that the resin solution (B2 to B6) containing the component (B2) has the acid generated in the exposed portion of the second resin film as compared with the case of the combination of the resin solution A and the resin solution B. This indicates that the film has diffused to the deep part of the film, that is, the acid has a long diffusion length.
On the other hand, the resin solution (B1) containing the component (D) had a shorter acid diffusion length than the resin solution A-resin solution B combination.
Moreover, since the resin solution B7 does not have an aromatic group in the cation part of the acid generator, it hardly absorbs at 193 nm, and can be regarded as a film reduction amount in an unexposed part (of the resin solutions B2 to B6). In addition, it was confirmed that the amount of film reduction was the same as that when the component (D) was contained.
From the above, in the resin solution B2, the diffusion length of the acid generated from the component (B1) only in the exposed portion is controlled to a certain extent, and the unexposed portion is controlled while the diffusion length of the acid generated from the component (B1) is short. It can be seen that, in the resin solution B1, the diffusion length of the acid generated from the component (B1) is shortened in both the exposed and unexposed areas.
Here, in the evaluation result of Example 1 containing the same component (B) as the resin solution B2, the DOF / pattern shape is improved, while the same component (B) as the resin solution B1 In the evaluation result of Reference Example 1 containing the component (D), the DOF is good, but the pattern shape is not improved. From the above, it is suggested that controlling the acid diffusion length in the unexposed area and increasing the acid diffusion length only in the exposed area contributes to improving the characteristics of the DOF / pattern shape.

  In addition, from the above, since the resin solutions B4 and B6 have the same amount of film loss as the resin solution B2, both the DOF and the pattern shape are also obtained by the resist composition containing the same component (B) as the resin solutions B4 and B6. Is expected to improve. And also in the resin solutions B3 and B5 containing twice the molar amount of the component (B2) in the resin solution B2, since the acid diffusion length of the exposed portion is extended (the amount of film reduction is large), the resin solution B3, According to the resist composition containing the same component (B) as B5, improvement in both characteristics can be expected.

In the resin solutions B2 to B6, the resin solutions B2, B4, and B6 are considered to have better limit resolution because the diffusion length is shorter than that in the case of the resin solutions B3 and B5 (mixing of 2 moles). It is done.
However, in the resin solution B7, since there is only a film reduction amount equivalent to the case where the (D) component is contained in the exposed portion, a resist using (B) -5 instead of the (B2) component as an acid generator. In the case of the composition, like the result of Reference Example 1, it is considered that the pattern shape is difficult to improve.

Claims (5)

A positive resist composition comprising a base component (A) whose solubility in an alkaline developer is increased by the action of an acid, and an acid generator component (B) that generates an acid upon exposure,
The base component (A) includes a structural unit (a0) represented by the following general formula (a0-1) and a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group. Containing the resin component (A1)
The acid generator component (B) includes at least one acid generator (B1) selected from the group consisting of compounds represented by any one of the following general formulas (1) to (3), and the following general formula ( 4) A positive resist composition comprising an acid generator (B2) comprising the compound represented by 4).

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; W represents a cyclic alkylene group which may contain an oxygen atom at an arbitrary position; To express. ]

[Wherein, X ¹⁰ is an optionally substituted hydrocarbon group having 3 to 30 carbon atoms, Q ¹ is a divalent linking group containing a carbonyl group, and p is an integer of 1 to 3. by ^{and; X 20} represents a hydrocarbon group having 3 to 30 carbon atoms which may have a substituent group, ^{Q 2} is a single bond or an alkylene group, q is an integer from 1 to ^{3; X 30} Is an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, Q ³ is a single bond or a divalent linking group, Y ¹⁰ is a carbonyl group or a sulfonyl group, and Y ¹¹ is An alkyl group having 1 to 10 carbon atoms which may have a substituent or a fluorinated alkyl group having 1 to 10 carbon atoms which may have a substituent; A ⁺ is a counter cation. ]

[In Formula (4), ^R0 is a C1-C12 hydrocarbon group which may have a substituent. However, the fluorine atom is not bonded to the carbon atom adjacent to the sulfur atom in —SO ₃ ^— . Ab ⁺ is a counter cation having an aromatic group. ] The positive resist composition according to claim 1, wherein the acid generator (B2) comprises a compound represented by the following general formula (b2-1).

[Wherein, X ⁴⁰ is a cyclic alkyl group having 4 to 12 carbon atoms which may have an oxygen atom (= O) as a substituent, r is 0 or 1, and Ab ⁺ is an aromatic group. Is a counter cation. ] Content of the said acid generator (B1) is 4-30 mass parts with respect to 100 mass parts of said base material components (A),
The positive resist composition according to claim 1 or 2, wherein the content of the acid generator (B2) is 0.1 to 4 parts by mass with respect to 100 parts by mass of the base component (A). The resin component (A1) further includes a structural unit derived from an acrylate ester containing a —SO ₂ -containing cyclic group and a structural unit derived from an acrylate ester containing a lactone-containing cyclic group. The positive resist composition as described in any one of Claims 1-3 which has at least 1 type of structural unit (a2) selected.   A step of forming a resist film on the support using the positive resist composition according to any one of claims 1 to 4, a step of exposing the resist film, and an alkali development of the resist film A resist pattern forming method including a step of forming a resist pattern.

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