JP7158946B2 - RESIN, RESIST COMPOSITION AND METHOD FOR MANUFACTURING RESIST PATTERN - Google Patents

Description

The present invention relates to a resin, a resist composition, a resist pattern manufacturing method using the resist composition, and the like.

特許文献２には、下記構造単位を有する樹脂を含有するレジスト組成物が記載されている。

Patent Document 1 describes a resist composition containing a resin having the following structural unit.

Patent Document 2 describes a resist composition containing a resin having the following structural unit.

Japanese Patent Application Laid-Open No. 2001-151719 JP 2009-157338 A

An object of the present invention is to provide a resin that forms a resist pattern with better line edge roughness (LER) than a resist pattern formed from a resist composition containing the above resin.

［式（Ｉ）中、
Ｒ^１は、水素原子又はメチル基を表す。
Ｘ^１は、単結合又は－ＣＯ－Ｏ－＊（＊は、Ａｒとの結合位を表す。）を表す。
Ａｒは、フッ素原子を有する炭素数６～３６の２価の芳香族炭化水素基を表す。
Ｒ^２は、水素原子又は酸不安定基を表す。］

［式（ａ１－１）及び式（ａ１－２）中、
Ｌ^ａ１及びＬ^ａ２は、それぞれ独立に、－Ｏ－又は＊－Ｏ－（ＣＨ_２）_ｋ１－ＣＯ－Ｏ－を表し、ｋ１は１～７のいずれかの整数を表し、＊は－ＣＯ－との結合手を表す。
Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組合せた基を表す。
ｍ１は、０～１４のいずれかの整数を表す。
ｎ１は、０～１０のいずれかの整数を表す。
ｎ１’は、０～３のいずれかの整数を表す。］
［２］Ｒ^２における酸不安定基が、式（１ａ）で表される基又は式（２ａ）で表される基である［１］記載の樹脂。

［式（１ａ）中、Ｒ^aa1、Ｒ^aa2及びＲ^aa3は、それぞれ独立に、置換基を有していてもよい炭素数１～８のアルキル基、もしくは置換基を有していてもよい炭素数３～２０の脂環式炭化水素基を表すか、又はＲ^aa1及びＲ^aa2は互いに結合してそれらが結合する炭素原子とともに炭素数３～２０の脂環式炭化水素基を形成する。
ｎａａは、０又は１を表す。
＊は結合手を表す。］

［式（２ａ）中、Ｒ^aa1’及びＲ^aa2’は、それぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^aa3’は、炭素数１～２０の炭化水素基を表すか、又はＲ^aa2’及びＲ^aa3’は互いに結合してそれらが結合する－Ｃ－Ｘ^ａ－とともに炭素数３～２０の複素環基を形成し、該炭化水素基及び該複素環基に含まれる－ＣＨ_２－は、－Ｏ－又は－Ｓ－で置き換わってもよい。
Ｘ^aは、酸素原子又は硫黄原子を表す。
＊は結合手を表す。］
［３］Ａｒが、フッ素原子を有するフェニレン基である［１］又は［２］に記載の樹脂。
［４］Ｘ^１が、単結合である［１］～［３］のいずれかに記載の樹脂。
［５］［１］～［４］のいずれかに記載の樹脂及び酸発生剤を含有するレジスト組成物。
［６］酸発生剤が、式（Ｂ１）で表される塩である［５］記載のレジスト組成物。

［式（Ｂ１）中、
Ｑ^ｂ１及びＱ^ｂ２は、それぞれ独立に、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｌ^ｂ１は、炭素数１～２４の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ（Ｏ）_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］
［７］酸発生剤から発生する酸よりも酸性度の弱い酸を発生する塩をさらに含有する［５］又は［６］載のレジスト組成物。
［８］（１）［５］～［７］のいずれかに記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A resin containing a structural unit represented by formula (I), a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2).

[in the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
X ¹ represents a single bond or -CO-O-* (* represents a bonding position with Ar).
Ar represents a divalent aromatic hydrocarbon group having 6 to 36 carbon atoms and having a fluorine atom.
^R2 represents a hydrogen atom or an acid labile group. ]

[In the formulas (a1-1) and (a1-2),
L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, k1 represents an integer of 1 to 7, * represents -CO- represents a bond with
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents any integer from 0 to 14;
n1 represents any integer from 0 to 10;
n1' represents an integer of 0 to 3; ]
[2] The resin according to [1], wherein the acid-labile group in ^R2 is a group represented by formula (1a) or a group represented by formula (2a).

[In the formula (1a), R ^aa1 , R ^aa2 and R ^aa3 are each independently an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^{aa1 and R aa2 are} bonded together to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
naa represents 0 or 1;
* represents a bond. ]

[In formula (2a), R ^{aa1 '} and R ^{aa2 '} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{aa3 '} represents a hydrocarbon group having 1 to 20 carbon atoms. or R ^aa2′ and R ^aa3′ are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with —C—X ^a — to which they are bonded, and the hydrocarbon group and the heterocyclic group -CH ₂ - included may be replaced with -O- or -S-.
X ^a represents an oxygen atom or a sulfur atom.
* represents a bond. ]
[3] The resin according to [1] or [2], wherein Ar is a phenylene group having a fluorine atom.
[4] The resin according to any one of [1] to [3], wherein X ¹ is a single bond.
[5] A resist composition containing the resin according to any one of [1] to [4] and an acid generator.
[6] The resist composition according to [5], wherein the acid generator is a salt represented by formula (B1).

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO— , a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S(O) ₂ - or -CO-.
Z ⁺ represents an organic cation. ]
[7] The resist composition according to [5] or [6], further comprising a salt that generates an acid weaker in acidity than the acid generated from the acid generator.
[8] (1) A step of applying the resist composition according to any one of [5] to [7] onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) A process of heating the composition layer after exposure, and (5) a process of developing the composition layer after heating.

By using a resist composition using the resin of the present invention, a resist pattern with good line edge roughness (LER) can be produced.

In this specification, unless otherwise specified, "(meth)acrylate" means "at least one selected from the group consisting of acrylate and methacrylate". Notations such as "(meth)acrylic acid" and "(meth)acryloyl" have the same meaning. Where structural units having "CH ₂ =C(CH ₃ )-CO-" or "CH ₂ =CH-CO-" are exemplified, structural units having both groups are similarly exemplified. shall be In addition, when stereoisomers exist, all stereoisomers are included.
As used herein, "the solid content of the resist composition" means the total amount of components excluding the solvent (E) described below from the total amount of the resist composition.

〔resin〕
The resin of the present invention includes a structural unit represented by formula (I) (hereinafter sometimes referred to as structural unit (I)), a structural unit represented by formula (a1-1) (hereinafter referred to as structural unit (a1 -1)) and a structural unit represented by formula (a1-2) (hereinafter sometimes referred to as structural unit (a1-2)) (hereinafter referred to as “resin (A)”) There are cases.).

<Structural unit (I)>
In formula (I), the divalent aromatic hydrocarbon group for Ar includes arylene groups having 6 to 36 carbon atoms such as phenylene group, naphthylene group and anthrylene group.
The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, more preferably 6 to 18 carbon atoms.
Ar is preferably a phenylene group having a fluorine atom or a naphthylene group having a fluorine atom, more preferably a phenylene group having a fluorine atom, and even more preferably a phenylene group having two or more fluorine atoms.

［式（１ａ）中、Ｒ^aa1、Ｒ^aa2及びＲ^aa3は、それぞれ独立に、置換基を有していてもよい炭素数１～８のアルキル基、もしくは置換基を有していてもよい炭素数３～２０の脂環式炭化水素基を表すか、又はＲ^aa1及びＲ^aa2は互いに結合してそれらが結合する炭素原子とともに炭素数３～２０の脂環式炭化水素基を形成する。
ｎａａは、０又は１を表す。
＊は結合手を表す。］

［式（２ａ）中、Ｒ^aa1’及びＲ^aa2’は、それぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^aa3’は、炭素数１～２０の炭化水素基を表すか、又はＲ^aa2’及びＲ^aa3’は互いに結合してそれらが結合する－Ｃ－Ｘ^ａ－とともに炭素数３～２０の複素環基を形成し、該炭化水素基及び該複素環基に含まれる－ＣＨ_２－は、－Ｏ－又は－Ｓ－で置き換わってもよい。
Ｘ^aは、酸素原子又は硫黄原子を表す。
＊は結合手を表す。］ The acid-labile group of ^R2 means a group having a leaving group that leaves upon contact with an acid to form a hydroxy group. Acid-labile groups include, for example, groups represented by formula (1a) (hereinafter sometimes referred to as "acid-labile groups (1a)"), groups represented by formula (2a) (hereinafter sometimes referred to as referred to as "acid-labile group (2a)").

[In the formula (1a), R ^aa1 , R ^aa2 and R ^aa3 are each independently an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^{aa1 and R aa2 are} bonded together to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
naa represents 0 or 1;
* represents a bond. ]

[In formula (2a), R ^{aa1 '} and R ^{aa2 '} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{aa3 '} represents a hydrocarbon group having 1 to 20 carbon atoms. or R ^aa2′ and R ^aa3′ are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with —C—X ^a — to which they are bonded, and the hydrocarbon group and the heterocyclic group -CH ₂ - included may be replaced with -O- or -S-.
X ^a represents an oxygen atom or a sulfur atom.
* represents a bond. ]

置換基を有していてもよい炭素数１～８のアルキル基の置換基としては、炭素数３～２０の脂環式炭化水素基が挙げられる。置換基を有していてもよい炭素数３～２０の脂環式炭化水素基の置換基としては、炭素数１～８のアルキル基が挙げられる。より具体的には、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、シクロヘキシルメチル基、アダマンチルメチル基、ノルボルニルエチル基等が挙げられる。
ｎａａは、好ましくは１である。
Ｒ^aa1及びＲ^aa2が互いに結合して脂環式炭化水素基を形成する場合の－Ｃ（Ｒ^aa1）（Ｒ^aa2）（Ｒ^aa3）としては、下記の基が挙げられる。脂環式炭化水素基は、好ましくは炭素数３～１２である。＊は－Ｏ－との結合手を表す。

^{Examples of alkyl groups represented by R aa1 to R aa3 include} methyl group, ethyl group, propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group and n-octyl group. be done.
Alicyclic hydrocarbon groups represented by R ^{aa1 to R aa3 may} be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl groups. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bond). The alicyclic hydrocarbon groups of R ^{aa1 to R aa3 preferably} have 3 to 16 carbon atoms.

Substituents for the optionally substituted alkyl group having 1 to 8 carbon atoms include alicyclic hydrocarbon groups having 3 to 20 carbon atoms. Substituents for the optionally substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms include alkyl groups having 1 to 8 carbon atoms. More specific examples include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, and a norbornylethyl group.
naa is preferably 1.
-C(R ^aa1 )(R ^aa2 )(R ^aa3 ) when R ^aa1 and R ^aa2 combine to form an alicyclic hydrocarbon group includes the following groups. The alicyclic hydrocarbon group preferably has 3-12 carbon atoms. * represents a bond with -O-.

Examples of groups represented by formula (1a) include 1,1-dialkylalkoxycarbonyl groups (groups in which R ^a1 to R ^a3 in formula (1a) are alkyl groups, preferably tert-butoxycarbonyl groups), 2- alkyladamantan-2-yloxycarbonyl group (in formula (1a), R ^{aa1 , R aa2 and} the carbon atoms to which they are bonded form an adamantyl group, and R ^aa3 is an alkyl group) and 1-(adamantane- 1-yl)-1-alkylalkoxycarbonyl group (in formula (1a), R ^aa1 and R ^aa2 are alkyl groups and R ^aa3 is an adamantyl group), and the like.

Ｒ^aa1'及びＲ^aa2'のうち、少なくとも１つは水素原子であることが好ましい。 The hydrocarbon groups represented by R ^aa1′ to R ^aa3′ include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, groups formed by combining these groups, and the like.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same groups as those listed for R ^a1 to R ^a3 .
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl and biphenyl groups. group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl, and the like.
When R ^aa2′ and R ^aa3′ are bonded to each other to form the carbon atom to which they are bonded and X ^a , —C(R ^a1′ )(R ^a3′ )—X—R ^a2′ is the following group are mentioned. * represents a bond.

At least one of R ^aa1′ and R ^aa2′ is preferably a hydrogen atom.

Specific examples of groups having an acid-labile group (1a) include the following groups. * represents a bond.

Specific examples of groups having an acid-labile group (2a) include the following groups. * represents a bond.

The acid-labile group represented by R ² is preferably a group having an acid-labile group (2a).
R ¹ is preferably a hydrogen atom.
X ¹ is preferably a single bond.
Ar is preferably a phenylene group having a fluorine atom.
R ² is preferably a hydrogen atom or a group having an acid labile group (2a).

Structural units (I) include structural units described below. Structural unit (I) includes structural unit (I-1) to structural unit (I-6), structural unit (I-9) to structural unit (I-12), structural unit (I-15) to structural unit ( I-21), structural units (I-24) to structural units (I-27), and structural units (I-30) are preferred, and structural units (I-1) to structural units (I-5), Structural unit (I-9), structural unit (I-15) to structural unit (I-18), structural unit (I-24), and structural unit (I-30) are more preferred, and structural unit (I -1) to structural unit (I-5), structural unit (I-9), and structural unit (I-15).

The content of structural unit (I) is generally 5 to 90 mol%, preferably 5 to 65 mol%, more preferably 10 to 50 mol%, based on the total monomers in resin (A). .
The resin (A) may contain two or more structural units (I).

［式（ａ１－１）及び式（ａ１－２）中、
Ｌ^ａ１及びＬ^ａ２は、それぞれ独立に、－Ｏ－又は＊－Ｏ－（ＣＨ_２）_ｋ１－ＣＯ－Ｏ－を表し、ｋ１は１～７のいずれかの整数を表し、＊は－ＣＯ－との結合手を表す。
Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組合せた基を表す。
ｍ１は、０～１４のいずれかの整数を表す。
ｎ１は、０～１０のいずれかの整数を表す。
ｎ１’は、０～３のいずれかの整数を表す。］ <Structural unit (a1-1) and structural unit (a1-2)>
Structural unit (a1-1) and structural unit (a1-2) are represented by the following formulas.

[In the formulas (a1-1) and (a1-2),
L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, k1 represents an integer of 1 to 7, * represents -CO- represents a bond with
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents any integer from 0 to 14;
n1 represents any integer from 0 to 10;
n1' represents an integer of 0 to 3; ]

R ^a4 and R ^a5 are preferably methyl groups.
L ^a1 and L ^a2 are preferably an oxygen atom or *—O—(CH ₂ ) _k01 —CO—O— (provided that k01 is preferably any integer of 1 to 4, more preferably 1 ), more preferably an oxygen atom.
Examples of the alkyl group, the alicyclic hydrocarbon group, and the group in which these groups are combined for R ^a6 and R ^a7 include the same groups as those listed for R ^{aa1 to R aa3 in} formula (1a).
The alkyl group in R ^a6 and R ^a7 preferably has 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and still more preferably a methyl group.
The alicyclic hydrocarbon groups of R ^a6 and R ^a7 preferably have 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.
It is preferable that the combined group of an alkyl group and an alicyclic hydrocarbon group have a total carbon number of 18 or less.
R ^a6 and R ^a7 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group or an isopropyl group, still more preferably an ethyl group or an isopropyl group.
m1 is preferably an integer from 0 to 3, more preferably 0 or 1.
n1 is preferably an integer from 0 to 3, more preferably 0 or 1.
n1′ is preferably an integer from 0 to 2, more preferably 0 or 1.

Examples of structural units (a1-1) include structural units derived from monomers described in JP-A-2010-204646. Among them, a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) and a methyl group corresponding to R ^a4 in structural unit (a1-1) is replaced with a hydrogen atom. Structural units are preferred, and structural units represented by any one of formulas (a1-1-1) to (a1-1-4) are more preferred.

The structural unit (a1-2) corresponds to a structural unit represented by any one of formulas (a1-2-1) to (a1-2-6) and R ^a5 in the structural unit (a1-2). Structural units in which a methyl group is substituted with a hydrogen atom are included, and formulas (a1-2-2), (a1-2-5) and (a1-2-6) are preferred.

The total content of structural units (a1-1) and/or structural units (a1-2) is usually 10 to 95 mol%, preferably 15 to 70 mol, relative to the total structural units of resin (A). %, more preferably 15 to 65 mol %, still more preferably 20 to 60 mol %, still more preferably 20 to 55 mol %.

［式（ａ１－０）中、
Ｌ^a01は、－Ｏ－又は^＊－Ｏ－（ＣＨ_２）_ｋ１－ＣＯ－Ｏ－を表し、ｋ１は１～７の整数を表し、＊は－ＣＯ－との結合手を表す。
Ｒ^a01は、水素原子又はメチル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組み合わせた基を表す。］ Resin (A) may further have a structural unit having an acid labile group other than structural unit (a1-1) and structural unit (a1-2).
Examples of the structural unit having an acid labile group other than the structural unit (a1-1) and the structural unit (a1-2) include a structural unit represented by formula (a1-0) (hereinafter referred to as structural unit (a1- 0)). These may be used alone or in combination of two or more.

[In the formula (a1-0),
L ^a01 represents -O- or ^* -O-(CH ₂ ) _k1 -CO-O-, k1 represents an integer of 1 to 7, and * represents a bond with -CO-.
R ^a01 represents a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof. ]

アルキル基と脂環式炭化水素基とを組み合わせた基としては、例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、シクロヘキシルメチル基、アダマンチルメチル基、アダマンチルジメチル基、ノルボルニルエチル基等が挙げられる。
Ｒ^a02、Ｒ^a03及びＲ^a04の脂環式炭化水素基の炭素数は、好ましくは３～８であり、より好ましくは３～６である。
アルキル基と脂環式炭化水素基とを組合せた基は、これらアルキル基と脂環式炭化水素基とを組合せた合計炭素数が、１８以下であることが好ましい。
Ｒ^a02及びＲ^a03は、好ましくは炭素数１～６のアルキル基であり、より好ましくはメチル基又はエチル基である。
Ｒ^a04は、好ましくは炭素数１～６のアルキル基又は炭素数５～１２の脂環式炭化水素基であり、より好ましくはメチル基、エチル基、シクロヘキシル基又はアダマンチル基である。 R ^a01 is preferably a methyl group.
L ^a01 is preferably an oxygen atom or *-O-(CH ₂ ) _k01 -CO-O- (provided that k01 is preferably any integer of 1 to 4, more preferably 1). , and more preferably an oxygen atom.
Examples of alkyl groups for R ^a02 , R ^a03 and R ^a04 include methyl group, ethyl group, propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group and n-octyl group. be done.
The alicyclic hydrocarbon groups of R ^a02 , R ^a03 and R ^a04 may be either monocyclic or polycyclic. The monocyclic alicyclic hydrocarbon group includes cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bond). The alicyclic hydrocarbon groups of R ^a02 , R ^a03 and R ^a04 preferably have 3 to 16 carbon atoms.

Groups in which an alkyl group and an alicyclic hydrocarbon group are combined include, for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl An ethyl group etc. are mentioned.
The number of carbon atoms in the alicyclic hydrocarbon groups of R ^a02 , R ^a03 and R ^a04 is preferably 3-8, more preferably 3-6.
It is preferable that the combined group of an alkyl group and an alicyclic hydrocarbon group have a total carbon number of 18 or less.
R ^a02 and R ^a03 are preferably alkyl groups having 1 to 6 carbon atoms, more preferably methyl or ethyl groups.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.

As the structural unit (a1-0), for example, a structural unit represented by any one of formulas (a1-0-1) to (a1-0-12) and a methyl group corresponding to R ^a01 is a hydrogen atom. Structural units having substitutions may be mentioned, and structural units represented by any one of formulas (a1-0-1) to (a1-0-10) are preferred.

When the resin (A) contains the structural unit (a1-0), its content is usually 5 to 60 mol%, preferably 5 to 50 mol%, based on the total structural units of the resin (A). Yes, more preferably 10 to 40 mol %.

［式（ａ１－４）中、
Ｒ^a32は、水素原子、ハロゲン原子、又は、ハロゲン原子を有していてもよい炭素数１～６のアルキル基を表す。
Ｒ^a33は、ハロゲン原子、ヒドロキシ基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数２～４のアルキルカルボニル基、炭素数２～４のアルキルカルボニルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
ｌａは０～４のいずれかの整数を表す。ｌａが２以上である場合、複数のＲ^a33は互いに同一であっても異なってもよい。
Ｒ^a34及びＲ^a35はそれぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^a36は、炭素数１～２０の炭化水素基を表すか、Ｒ^a35及びＲ^a36は互いに結合してそれらが結合する－Ｃ－Ｏ－とともに炭素数２～２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。］ The structural unit having an acid labile group other than the structural unit (a1-1) and the structural unit (a1-2) includes a structural unit represented by the formula (a1-4) (hereinafter referred to as “structural unit (a1-4 )” may also be mentioned.

[In formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl It represents an oxy group or a methacryloyloxy group.
la represents an integer of 0 to 4; When la is 2 or more, a plurality of R ^a33 may be the same or different.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^a35 and R ^a36 are bonded to each other to form a C2-C20 divalent hydrocarbon group together with -C-O- to which they are bonded, and -CH ₂ - contained in the hydrocarbon group and the divalent hydrocarbon group is - O- or -S- may be substituted. ]

Examples of alkyl groups for R ^a32 and R ^a33 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group and hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, even more preferably a methyl group.
Halogen atoms in R ^a32 and R ^a33 include fluorine, chlorine and bromine atoms.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1 , 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, etc. are mentioned.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy and hexyloxy groups. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is even more preferable.
Alkylcarbonyl groups include acetyl, propionyl and butyryl groups.
An acetyloxy group, a propionyloxy group, a butyryloxy group, etc. are mentioned as an alkylcarbonyloxy group.
The hydrocarbon groups for R ^a34 , R ^a35 and R ^a36 include alkyl groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, and the same groups as R aa1′ and R ^{aa2 ′} in formula (2a). are mentioned. In particular, R ^a36 is an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these groups. are mentioned.
--OC(R ^a34 )(R ^a35 )-OR ^a36 in the structural unit (a1-4) is eliminated upon contact with an acid (eg, p-toluenesulfonic acid) to form a hydroxy group.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group.
la is preferably 0 or 1, more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group, more preferably a methyl group or an ethyl group.
The hydrocarbon group of R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination of these A group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and the alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. The aromatic hydrocarbon group for R ^a36 is preferably an aromatic ring having an aryloxy group with 6 to 10 carbon atoms.

Examples of structural units (a1-4) include structural units derived from monomers described in JP-A-2010-204646. Preferred are structural units represented by formulas (a1-4-1) to (a1-4-8) and structural units in which a hydrogen atom corresponding to R ^a32 is replaced with a methyl group, more preferably , and structural units represented by formulas (a1-4-1) to (a1-4-5).

When the resin (A) has the structural unit (a1-4), the content thereof is preferably 5 to 60 mol%, preferably 5 to 50 mol%, based on the total of all structural units of the resin (A). It is more preferably mol %, and even more preferably 10 to 40 mol %.

式（ａ１－５）中、
Ｒ^a8は、ハロゲン原子を有していてもよい炭素数１～６のアルキル基、水素原子又はハロゲン原子を表す。
Ｚ^a1は、単結合又は＊－（ＣＨ₂）_h3－ＣＯ－Ｌ⁵⁴－を表し、ｈ３は１～４のいずれかの整数を表し、＊は、Ｌ⁵¹との結合手を表す。
Ｌ⁵¹、Ｌ⁵²、Ｌ⁵³及びＬ⁵⁴は、それぞれ独立に、－Ｏ－又は－Ｓ－を表す。
ｓ１は、１～３のいずれかの整数を表す。
ｓ１’は、０～３のいずれかの整数を表す。 The structural unit having an acid labile group other than the structural unit (a1-1) and the structural unit (a1-2) includes a structural unit represented by the formula (a1-5) (hereinafter “structural unit (a1-5) ”) can also be mentioned.

In formula (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or *—(CH ₂ ) _h3 —CO—L ⁵⁴ —, h3 represents an integer of 1 to 4, and * represents a bond with L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent -O- or -S-.
s1 represents any integer from 1 to 3;
s1′ represents any integer from 0 to 3;

Halogen atoms include fluorine atoms and chlorine atoms, with fluorine atoms being preferred.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, fluoromethyl group and trifluoro A methyl group is mentioned.
In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
Preferably, one of L ⁵² and L ⁵³ is —O— and the other is —S—.
As for s1, 1 is preferable.
s1' is preferably an integer of 0-2.
Z ^a1 is preferably a single bond or *—CH ₂ —CO—O—.

Examples of structural units (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among them, structural units represented by formulas (a1-5-1) to (a1-5-4) are preferable, and represented by formula (a1-5-1) or formula (a1-5-2) Structural units are more preferred.

When the resin (A) has the structural unit (a1-5), the content thereof is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on the total structural units of the resin (A). , 5 to 40 mol % is more preferable.

［式（ａ１－０Ｘ）中、
Ｒ^ｘ１は、水素原子又はメチル基を表す。
Ｒ^ｘ２及びＲ^ｘ３は、それぞれ独立に、炭素数１～６の飽和炭化水素基を表す。
Ａｒ^ｘ１は、炭素数６～３６の芳香族炭化水素基を表す。］ Examples of the structural unit having an acid labile group other than the structural unit (a1-1) and the structural unit (a1-2) include a structural unit represented by the formula (a1-0X) (hereinafter referred to as structural unit (a1- 0X).) is also included. Two or more of the structural units (a1-0X) may be selected and added to the resin (A).

[In the formula (a1-0X),
R ^x1 represents a hydrogen atom or a methyl group.
R ^x2 and R ^x3 each independently represent a saturated hydrocarbon group having 1 to 6 carbon atoms.
Ar ^x1 represents an aromatic hydrocarbon group having 6 to 36 carbon atoms. ]

Saturated hydrocarbon groups for R ^x2 and R ^x3 include alkyl groups, alicyclic hydrocarbon groups, and groups formed by combinations thereof.
Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl and hexyl groups.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups.
The aromatic hydrocarbon group for Ar ^x1 includes aryl groups having 6 to 36 carbon atoms such as phenyl group, naphthyl group and anthryl group.
The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, more preferably 6 to 18 carbon atoms, and still more preferably a phenyl group.
Ar ^x1 is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, more preferably a phenyl group or a naphthyl group, still more preferably a phenyl group.
R ^x1 , R ^x2 and R ^x3 are each independently preferably a methyl group or an ethyl group, more preferably a methyl group.

Ｒ^ｘ１に相当するメチル基が水素原子に置き換わった化合物も、構造単位（ａ１－０Ｘ）の具体例として挙げることができる。 Examples of the structural unit (a1-0X) include structural units described below. Structural unit (a1-0X) is preferably structural unit (a1-0X-1) to structural unit (a1-0X-3).

A compound in which a methyl group corresponding to R ^x1 is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a1-0X).

When the resin (A) has the structural unit (a1-0X), the content thereof is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, based on the total monomers in the resin (A). more preferably 10 to 40 mol %.
The resin (A) may contain two or more structural units (a1-0X).

Structural units having an acid-labile group other than the structural units (a1-1) and (a1-2) also include the following structural units.

When the resin (A) contains the above structural unit, its content is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, and 10 to 40 mol, based on the total structural units of the resin (A). % is more preferred.

The resin (A) further contains a structural unit (hereinafter sometimes referred to as "structural unit (s)") derived from a monomer having no acid labile group (hereinafter sometimes referred to as "monomer (s)"). structural unit, for example, a structural unit having a halogen atom (hereinafter sometimes referred to as "structural unit (a4)"), a structural unit having a non-leaving hydrocarbon group having no halogen atom (hereinafter "structural unit (a5 )”) and/or other structural units derived from monomers known in the art.

<Structural unit (s)>
The structural unit (s) is derived from a monomer having no halogen atoms and no acid-labile group (hereinafter sometimes referred to as "monomer (s)"). As a monomer leading to the structural unit (s), a monomer having no acid-labile group known in the field of resists can be used.
The structural unit (s) preferably has a hydroxy group or a lactone ring. A structural unit having a hydroxy group and no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and/or a structure having a lactone ring and no acid-labile group When a resin having a unit (hereinafter sometimes referred to as "structural unit (a3)") is used in the resist composition of the present invention, the resolution of the resist pattern and adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group possessed by the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When producing a resist pattern from the resist composition of the present invention, when using a high-energy beam such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) as an exposure light source, the structural unit (a2) , it is preferable to use a structural unit (a2) having a phenolic hydroxy group. When using an ArF excimer laser (193 nm) or the like, the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, and more preferably a structural unit (a2-1) described later. preferable. As the structural unit (a2), one type may be contained alone, or two or more types may be contained. Further, when high-energy rays such as electron beams or EUV (extreme ultraviolet light) are used, it is preferable to contain the structural unit (a2-A) without containing the structural unit (a2-1), which will be described later.

［式（ａ２－Ａ）中、
Ｒ^a50は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１～６のアルキル基を表す。
Ｒ^a51は、ハロゲン原子、ヒドロキシ基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数２～４のアルキルカルボニル基、炭素数２～４のアルキルカルボニルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
Ａ^a50は、単結合又は^＊－Ｘ^a51－（Ａ^a52－Ｘ^a52）_nｂ－を表し、＊は－Ｒ^a50が結合する炭素原子との結合位を表す。
Ａ^a52は、それぞれ独立に、炭素数１～６のアルカンジイル基を表す。
Ｘ^a51及びＸ^a52は、それぞれ独立に、－Ｏ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ｎｂは、０又は１を表す。
ｍｂは０～４のいずれかの整数を表す。ｍｂが２以上のいずれかの整数である場合、複数のＲ^a51は互いに同一であっても異なってもよい。］ Structural units having a phenolic hydroxy group in structural units (a2) include structural units represented by formula (a2-A) (hereinafter sometimes referred to as “structural unit (a2-A)”).

[In the formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl It represents an oxy group or a methacryloyloxy group.
A ^a50 represents a single bond or ^* -X ^a51 -(A ^a52 -X ^a52 ) _nb -, and * represents the bonding position with the carbon atom to which -R ^a50 bonds.
Each A ^a52 independently represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent -O-, -CO-O- or -O-CO-.
nb represents 0 or 1;
mb represents an integer from 0 to 4; When mb is any integer of 2 or more, multiple R ^a51 may be the same or different. ]

Halogen atoms in R ^a50 include fluorine, chlorine and bromine atoms.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom for R ^a50 include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1 , 1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluorohexyl groups.
R ^a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, even more preferably a hydrogen atom or a methyl group.
Examples of alkyl groups for R ^a51 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl and hexyl groups.
Alkoxy groups for R ^a51 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy and tert-butoxy groups. An alkoxy group having 1 to 4 carbon atoms is preferred, a methoxy group or an ethoxy group is more preferred, and a methoxy group is even more preferred.
The alkylcarbonyl group for R ^a51 includes an acetyl group, a propionyl group and a butyryl group.
The alkylcarbonyloxy group for R ^a51 includes an acetyloxy group, a propionyloxy group and a butyryloxy group.
R ^a51 is preferably a methyl group.

^* -X ^a51 -(A ^a52 -X ^a52 ) _nb - is ^* -O-, ^* -CO-O-, ^* -O-CO-, ^* -CO-O-A ^a52 -CO-O-, ^* -O-CO-A ^a52 -O-, ^* -O-A ^a52 -CO-O-, ^* -CO-O-A ^a52 -O-CO-, ^* -O-CO-A ^a52 -O-CO -, are included. Among them, ^* -CO-O-, ^* -CO-OA ^a52 -CO-O- and ^{* -OA a52} -CO-O- are preferred.
The alkanediyl group includes methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane- 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2 -methylbutane-1,4-diyl group and the like.
A ^a52 is preferably a methylene group or an ethylene group.
A ^a50 is preferably a single bond, ^* -CO-O- or ^* -CO-O-A ^a52 -CO-O-, a single bond, ^* -CO-O- or ^* -CO-O-CH ₂ --CO--O-- is more preferred, and a single bond or ^* --CO--O-- is even more preferred.
mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.
The hydroxy group is preferably bonded to the o-position or p-position of the benzene ring, more preferably bonded to the p-position.

Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577.
The structural unit (a2-A) includes structural units represented by formulas (a2-2-1) to (a2-2-4) and formulas (a2-2-1) to (a2-2- Examples of the structural unit represented by 4) include a structural unit in which the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom. Structural unit (a2-A) is a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3) and a structural unit represented by formula (a2-2-1). or the structural unit represented by the formula (a2-2-3), the structural unit is preferably a structural unit in which the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom.

When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 5 to 80 mol%, more preferably It is 10 to 70 mol %, more preferably 15 to 65 mol %, still more preferably 20 to 65 mol %.
The structural unit (a2-A) can be included in the resin (A), for example, by polymerizing the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Also, the structural unit (a2-A) can be included in the resin (A) by polymerizing with acetoxystyrene or the like and then treating with an alkali such as tetramethylammonium hydroxide.

式（ａ２－１）中、
Ｌ^a3は、－Ｏ－又は^＊－Ｏ－（ＣＨ₂）_k2－ＣＯ－Ｏ－を表し、
ｋ２は１～７のいずれかの整数を表す。＊は－ＣＯ－との結合位を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０～１０のいずれかの整数を表す。 A structural unit having an alcoholic hydroxy group in the structural unit (a2) includes a structural unit represented by formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)").

In formula (a2-1),
L ^a3 represents —O— or ^* —O—(CH ₂ ) _k2 —CO—O—;
k2 represents any integer from 1 to 7; * represents the bonding position with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents any integer from 0 to 10;

In formula (a2-1), L ^a3 is preferably -O-, -O-(CH ₂ ) _f1 -CO-O- (f1 represents an integer of 1 to 4) , more preferably -O-.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably any integer from 0 to 3, more preferably 0 or 1.

Examples of the structural unit (a2-1) include structural units derived from monomers described in JP-A-2010-204646. Structural units represented by any one of formulas (a2-1-1) to (a2-1-6) are preferred, and any one of formulas (a2-1-1) to (a2-1-4) Structural units represented by formula (a2-1-1) or formula (a2-1-3) are more preferable.

When the resin (A) contains the structural unit (a2-1), its content is usually 1 to 45 mol%, preferably 1 to 40 mol%, based on the total structural units of the resin (A). Yes, more preferably 1 to 35 mol %, still more preferably 2 to 20 mol %, still more preferably 2 to 10 mol %.

［式（ａ３－１）、式（ａ３－２）、式（ａ３－３）及び式（ａ３－４）中、
Ｌ^ａ４、Ｌ^ａ５及びＬ^ａ６は、それぞれ独立に、－Ｏ－又は^＊－Ｏ－（ＣＨ_２）_ｋ３－ＣＯ－Ｏ－（ｋ３は１～７のいずれかの整数を表す。）で表される基を表す。
Ｌ^ａ７は、－Ｏ－、^＊－Ｏ－Ｌ^ａ８－Ｏ－、^＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－、^＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－Ｌ^ａ９－ＣＯ－Ｏ－又は^＊－Ｏ－Ｌ^ａ８－Ｏ－ＣＯ－Ｌ^ａ９－Ｏ－を表す。
Ｌ^ａ８及びＬ^ａ９は、それぞれ独立に、炭素数１～６のアルカンジイル基を表す。
＊はカルボニル基との結合位を表す。
Ｒ^ａ１８、Ｒ^ａ１９及びＲ^ａ２０は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ２４は、ハロゲン原子を有してもよい炭素数１～６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^ａ２１は炭素数１～４の脂肪族炭化水素基を表す。
Ｒ^ａ２２、Ｒ^ａ２３及びＲ^ａ２５は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１～４の脂肪族炭化水素基を表す。
ｐ１は０～５のいずれかの整数を表す。
ｑ１は、０～３のいずれかの整数を表す。
ｒ１は、０～３のいずれかの整数を表す。
ｗ１は、０～８のいずれかの整数を表す。
ｐ１、ｑ１、ｒ１及び／又はｗ１が２以上のとき、複数のＲ^ａ２１、Ｒ^ａ２２、Ｒ^ａ２３及び／又はＲ^ａ２５は互いに同一であってもよく、異なっていてもよい。］ <Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocyclic ring such as a β-propiolactone ring, γ-butyrolactone ring, δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. It's okay. Preferable examples include a γ-butyrolactone ring, an adamantanelactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).
Structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4). One of these may be contained alone, or two or more may be contained.

[In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4),
L ^a4 , L ^a5 and L ^a6 are each independently represented by —O— or ^* —O—(CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7); represents a group.
L ^a7 is -O-, ^* -OL ^a8 -O-, ^* -OL ^a8 -CO-O-, ^* -OL ^a8 -CO- ^{OL a9} -CO-O- or ^* -OL ^a8 -O-CO-L ^a9 -O-.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* represents the bonding position with the carbonyl group.
R ^a18 , R ^a19 and R ^a20 each independently represent a hydrogen atom or a methyl group.
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 each independently represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents any integer from 0 to 5;
q1 represents an integer of 0 to 3;
r1 represents an integer of 0 to 3;
w1 represents any integer from 0 to 8;
When p1, q1, r1 and/or w1 are 2 or more, a plurality of R ^a21 , R ^a22 , R ^a23 and/or R ^a25 may be the same or different. ]

Examples of the aliphatic hydrocarbon group for R ^a21 , R ^a22 , R ^a23 and R ^a25 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group and tert-butyl group. be done.
Halogen atoms in R ^a24 include fluorine, chlorine, bromine and iodine atoms.
Examples of the alkyl group for R ^a24 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group, preferably having 1 to 4 carbon atoms. and more preferably a methyl group or an ethyl group.
The alkyl group having a halogen atom for R ^a24 includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluoro A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group and the like can be mentioned.
The alkanediyl group for L ^a8 and L ^a9 includes methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5 -diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, 4-diyl group, 2-methylbutane-1,4-diyl group and the like.

（式中、Ｒ^ａ２４、Ｌ^ａ７は、上記と同じ意味を表す。） In formulas (a3-1) to (a3-3), L ^a4 to L ^a6 are each independently preferably —O— or *—O—(CH ₂ ) _k3 —CO—O—, k3 is an integer of 1 to 4, more preferably -O- and *-O-CH ₂ -CO-O-, more preferably an oxygen atom.
R ^a18 to R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.
In formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, still more preferably a hydrogen atom or a methyl group is.
R ^a25 is preferably a carboxy group, a cyano group or a methyl group.
L ^a7 is preferably -O- or ^* -OL ^a8 -CO-O-, more preferably -O-, -O-CH ₂ -CO-O- or -O-C ₂ H ₄ - It is CO—O—.
w1 is preferably an integer from 0 to 2, more preferably 0 or 1.
In particular, formula (a3-4) is preferably formula (a3-4)'.

(In the formula, R ^a24 and L ^a7 have the same meanings as above.)

As the structural unit (a3), the monomer described in JP-A-2010-204646, the monomer described in JP-A-2000-122294, the structure derived from the monomer described in JP-A-2012-41274 units. As the structural unit (a3), formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3- 1), a structural unit represented by any one of formulas (a3-3-2) and formulas (a3-4-1) to (a3-4-12), and in said structural unit, formula (a3-1 ) to R ^a18 , R ^a19 , R ^a20 and R ^a24 in formulas (a3-4) are preferably structural units in which methyl groups are replaced with hydrogen atoms.

When the resin (A) contains the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on the total structural units of the resin (A). , more preferably 10 to 60 mol %.
Further, the content of structural unit (a3-1), structural unit (a3-2), structural unit (a3-3) or structural unit (a3-4) is 5 to 60 mol % is preferred, 5 to 50 mol % is more preferred, and 10 to 50 mol % is even more preferred.

［式（ａ４）中、
Ｒ⁴¹は、水素原子又はメチル基を表す。
Ｒ⁴²は、炭素数１～２４のフッ素原子を有する飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯに置き換わっていてもよい。］
Ｒ⁴²で表される飽和炭化水素基は、鎖式炭化水素基及び単環又は多環の脂環式炭化水素基、並びに、これらを組み合わせることにより形成される基等が挙げられる。
鎖式炭化水素基としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、デシル基、ドデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基及びオクタデシル基が挙げられる。単環又は多環の脂環式炭化水素基としては、シクロペンチル基、シクロへキシル基、シクロヘプチル基、シクロオクチル基等のシクロアルキル基；デカヒドロナフチル基、アダマンチル基、ノルボルニル基及び下記の基（＊は結合位を表す。）等の多環式の脂環式炭化水素基が挙げられる。

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式炭化水素基とを組み合わせることにより形成される基が挙げられ、－アルカンジイル基－脂環式炭化水素基、－脂環式炭化水素基－アルキル基、－アルカンジイル基－脂環式炭化水素基－アルキル基等が挙げられる。 <Structural unit (a4)>
Structural units (a4) include the following structural units.

[In formula (a4),
R ⁴¹ represents a hydrogen atom or a methyl group.
R ⁴² represents a saturated hydrocarbon group having 1 to 24 fluorine atoms, and --CH ₂ -- contained in the saturated hydrocarbon group may be replaced with --O-- or --CO. ]
Examples of saturated hydrocarbon groups represented by R ⁴² include chain hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these groups.
Chain hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl groups. mentioned. Monocyclic or polycyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl; decahydronaphthyl, adamantyl, norbornyl and the following groups (* represents a bonding position.) and other polycyclic alicyclic hydrocarbon groups.

Groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, and -alkanediyl groups- Alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic hydrocarbon group-alkyl group and the like.

［式（ａ４－０）中、
Ｒ⁵は、水素原子又はメチル基を表す。
Ｌ^4ａは、単結合又は炭素数１～４のアルカンジイル基を表す。
Ｌ^3ａは、炭素数１～８のペルフルオロアルカンジイル基又は炭素数３～１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ⁶は、水素原子又はフッ素原子を表す。］ The structural unit (a4) is at least selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3) and formula (a4-4) Structural units represented by one are exemplified.

[In the formula (a4-0),
^R5 represents a hydrogen atom or a methyl group.
L ^4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms.
L ^3a represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
^R6 represents a hydrogen atom or a fluorine atom. ]

The alkanediyl group for L ^4a includes linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, ethane-1,1-diyl, branched alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group; be done.
The perfluoroalkanediyl group for L ^3a includes a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane-2,2 -diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2 -diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7 -diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2 -diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
The perfluorocycloalkanediyl group for L ^3a includes a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.
L ^4a is preferably a single bond, a methylene group or an ethylene group, more preferably a single bond or a methylene group.
L ^3a is preferably a C 1-6 perfluoroalkanediyl group, more preferably a C 1-3 perfluoroalkanediyl group.

Examples of the structural unit (a4-0) include structural units shown below and structural units in which the methyl group corresponding to R ⁵ in the structural unit (a4-0) in the following structural units is replaced with a hydrogen atom.

［式（ａ４－１）中、
Ｒ^a41は、水素原子又はメチル基を表す。
Ｒ^a42は、置換基を有していてもよい炭素数１～２０の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
Ａ^a41は、置換基を有していてもよい炭素数１～６のアルカンジイル基又は式（ａ－ｇ１）で表される基を表す。ただし、Ａ^ａ４１及びＲ^ａ４２のうち少なくとも１つは、置換基としてハロゲン原子（好ましくはフッ素原子）を有する。

〔式（ａ－ｇ１）中、
ｓは０又は１を表す。
Ａ^a42及びＡ^a44は、それぞれ独立に、置換基を有していてもよい炭素数１～５の２価の飽和炭化水素基を表す。
Ａ^a43は、単結合又は置換基を有していてもよい炭素数１～５の２価の脂肪族炭化水素基を表す。
Ｘ^a41及びＸ^a42は、それぞれ独立に、－Ｏ－、－ＣＯ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ただし、Ａ^a42、Ａ^a43、Ａ^a44、Ｘ^a41及びＸ^a42の炭素数の合計は７以下である。〕
＊は結合位であり、右側の＊が－Ｏ－ＣＯ－Ｒ^a42との結合位である。］

[In formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O— or —CO— may
A ^a41 represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by formula (a-g1). However, at least one of A ^a41 and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent.

[In formula (a-g1),
s represents 0 or 1;
A ^a42 and A ^a44 each independently represent an optionally substituted divalent saturated hydrocarbon group having 1 to 5 carbon atoms.
A ^a43 represents a single bond or an optionally substituted C 1-5 divalent aliphatic hydrocarbon group.
X ^a41 and X ^a42 each independently represent -O-, -CO-, -CO-O- or -O-CO-.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. ]
* is the bonding position, and * on the right side is the bonding position with —O—CO—R ^a42 . ]

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式炭化水素基とを組み合わせることにより形成される基が挙げられ、－アルカンジイル基－脂環式炭化水素基、－脂環式炭化水素基－アルキル基、－アルカンジイル基－脂環式炭化水素基－アルキル基等が挙げられる。
Ｒ^a42が有する置換基として、ハロゲン原子又は式（ａ－ｇ３）で表される基を有していてもよい。ハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子が挙げられ、好ましくはフッ素原子である。

［式（ａ－ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＲ^a42との結合位を表す。）。
Ａ^a45は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
＊は結合位を表す。］
ただし、Ｒ^a42－Ｘ^a43－Ａ^a45において、Ｒ^a42がハロゲン原子を有しない場合は、Ａ^a45は、少なくとも１つのハロゲン原子を有する炭素数１～１７の脂肪族炭化水素基を表す。 Examples of saturated hydrocarbon groups for R ^a42 include chain hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these groups.
Chain hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl groups. mentioned. Monocyclic or polycyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl; decahydronaphthyl, adamantyl, norbornyl and the following groups (* represents a bond) and other polycyclic alicyclic hydrocarbon groups.

Groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, and -alkanediyl groups- Alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic hydrocarbon group-alkyl group and the like.
R ^a42 may have a halogen atom or a group represented by formula (a-g3) as a substituent. A halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a fluorine atom.

[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, *--O--CO-- or *--CO--O-- (* represents the bonding position with R ^a42 ).
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
* represents a bonding position. ]
However, in R ^a42 -X ^a43 -A ^a45 , when R ^a42 does not have a halogen atom, A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and having at least one halogen atom.

Aliphatic hydrocarbon groups for A ^a45 include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and an alkyl group such as an octadecyl group;
Monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; and decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bond ) and other polycyclic alicyclic hydrocarbon groups.

［式（ａ－ｇ２）中、
Ａ^a46は、ハロゲン原子を有していてもよい炭素数１～１７の２価の脂肪族炭化水素基を表す。
Ｘ^a44は、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＡ^a46との結合位を表す。）。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
ただし、Ａ^a46、Ａ^a47及びＸ^a44の炭素数の合計は１８以下であり、Ａ^a46及びＡ^a47のうち、少なくとも一方は、少なくとも１つのハロゲン原子を有する。
＊はカルボニル基との結合位を表す。］ R ^a42 is preferably a saturated hydrocarbon group optionally having a halogen atom, more preferably an alkyl group having a halogen atom and/or a saturated hydrocarbon group having a group represented by formula (a-g3).
When R ^a42 is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably having 1 to 1 carbon atoms. A perfluoroalkyl group having 6 carbon atoms, particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Perfluoroalkyl groups include perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl and perfluorooctyl groups. A perfluorocyclohexyl group etc. are mentioned as a perfluorocycloalkyl group.
When R ^a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), the total carbon number of R ^a42 including the number of carbon atoms contained in the group represented by formula (a-g3) The number is preferably 15 or less, more preferably 12 or less. When it has a group represented by formula (a-g3) as a substituent, the number thereof is preferably one.
When R ^a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), R ^a42 is more preferably a group represented by formula (a-g2).

[In the formula (a-g2),
A ^a46 represents a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents *--O--CO-- or *--CO--O-- (* represents the bonding position with A ^a46 ).
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* represents the bonding position with the carbonyl group. ]

The number of carbon atoms in the aliphatic hydrocarbon group of A ^a46 is preferably 1-6, more preferably 1-3.
The number of carbon atoms in the aliphatic hydrocarbon group of A ^a47 is preferably 4 to 15, more preferably 5 to 12, and A ^a47 is more preferably a cyclohexyl group or an adamantyl group.
A preferred structure of the group represented by formula (a-g2) is the following structure (* is the bonding position with the carbonyl group).

Alkanediyl group for A ^a41 includes methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group straight-chain alkanediyl groups such as; A branched alkanediyl group such as a 2-methylbutane-1,4-diyl group can be mentioned.
Examples of substituents on the alkanediyl group represented by A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and still more preferably an ethylene group.

The divalent saturated hydrocarbon groups represented by A ^a42 , A ^a43 and A ^a44 in the group represented by the formula (a-g1) include linear or branched alkanediyl groups and monocyclic divalent alicyclic Hydrocarbon groups, groups formed by combining an alkanediyl group and a divalent alicyclic hydrocarbon group, and the like. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group and the like.
Substituents of the divalent saturated hydrocarbon groups represented by A ^a42 , A ^a43 and A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably zero.

In the group represented by the formula (ag2), examples of the group in which X ^a42 is -O-, -CO-, -CO-O- or -O-CO- include the following groups. In the following examples, * and ** each represent a bonding position, and ** is the bonding position with --O--CO--R ^a42 .

The structural unit represented by formula (a4-1) includes the structural units shown below and the methyl group corresponding to R ^a41 in the structural unit represented by formula (a4-1) in the following structural units is replaced with a hydrogen atom. Structural units replaced are included.

［式（ａ４－２）中、
Ｒ^f5は、水素原子又はメチル基を表す。
Ｌ⁴⁴は、炭素数１～６のアルカンジイル基を表し、該アルカンジイル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
Ｒ^f6は、炭素数１～２０のフッ素原子を有する飽和炭化水素基を表す。
ただし、Ｌ⁴⁴及びＲ^f6の合計炭素数の上限は２１である。］
Ｌ⁴⁴のアルカンジイル基は、Ｌ^4ａで例示したものと同様の基が挙げられる。
Ｒ^f6の飽和炭化水素基は、Ｒ^a42で例示したものと同様の基が挙げられる。
Ｌ^４4における炭素数１～６のアルカンジイル基としては、炭素数２～４のアルカンジイル基が好ましく、エチレン基がより好ましい。 As the structural unit represented by formula (a4-1), a structural unit represented by formula (a4-2) is preferable.

[In formula (a4-2),
R ^f5 represents a hydrogen atom or a methyl group.
L ⁴⁴ represents an alkanediyl group having 1 to 6 carbon atoms, and --CH ₂ -- contained in the alkanediyl group may be replaced with --O-- or --CO--.
R ^f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and a fluorine atom.
However, the upper limit of the total carbon number of L ⁴⁴ and R ^f6 is 21. ]
Examples of the alkanediyl group for L ⁴⁴ include the same groups as those exemplified for L ^4a .
Examples of the saturated hydrocarbon group for R ^f6 include the same groups as those exemplified for R ^a42 .
The alkanediyl group having 1 to 6 carbon atoms in L ⁴⁴ is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.

Examples of structural units represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11). A structural unit in which the methyl group corresponding to R ^f5 in the structural unit (a4-2) is replaced with a hydrogen atom is also included as the structural unit represented by the formula (a4-2).

［式（ａ４－３）中、
Ｒ^f7は、水素原子又はメチル基を表す。
Ｌ⁵は、炭素数１～６のアルカンジイル基を表す。
Ａ^f13は、フッ素原子を有していてもよい炭素数１～１８の２価の飽和炭化水素基を表す。
Ｘ^f12は、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＡ^f13との結合位を表す。）。
Ａ^f14は、フッ素原子を有していてもよい炭素数１～１７の飽和炭化水素基を表す。
但し、Ａ^f13及びＡ^f14の少なくとも１つは、フッ素原子を有し、Ｌ⁵、Ａ^f13及びＡ^f14の合計炭素数の上限は２０である。］ Structural units (a4) include structural units represented by formula (a4-3).

[In formula (a4-3),
R ^f7 represents a hydrogen atom or a methyl group.
L ⁵ represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents a C 1-18 divalent saturated hydrocarbon group which may have a fluorine atom.
X ^f12 represents *--O--CO-- or *--CO--O-- (* represents the bonding position with A ^f13 ).
A ^f14 represents a C 1-17 saturated hydrocarbon group which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 has a fluorine atom, and the upper limit of the total carbon number of L ⁵ , A ^f13 and A ^f14 is 20. ]

The alkanediyl group for L ⁵ includes the same groups as those exemplified for the alkanediyl group for L ^4a .
The divalent saturated hydrocarbon group which may have a fluorine atom in A ^f13 is preferably a divalent aliphatic saturated hydrocarbon group which may have a fluorine atom and a fluorine atom-containing is a divalent saturated alicyclic hydrocarbon group, more preferably a perfluoroalkanediyl group.
The divalent aliphatic hydrocarbon group which may have a fluorine atom includes alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group and a pentanediyl group; a difluoromethylene group, a perfluoroethylene group, a perfluoro and perfluoroalkanediyl groups such as a propanediyl group, a perfluorobutanediyl group and a perfluoropentanediyl group.
The divalent alicyclic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Monocyclic groups include a cyclohexanediyl group, a perfluorocyclohexanediyl group, and the like. Examples of polycyclic groups include an adamantanediyl group, a norbornanediyl group, a perfluoroadamantanediyl group, and the like.
Examples of saturated hydrocarbon groups and optionally fluorine-containing saturated hydrocarbon groups for A ^f14 include groups similar to those exemplified for R ^a42 . Among them, trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, Fluorination such as 2,2,3,3,4,4,5,5,5-nonafluoropentyl, pentyl, hexyl, perfluorohexyl, heptyl, perfluoroheptyl, octyl and perfluorooctyl groups Alkyl group, cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, perfluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group, norbornylmethyl group, perfluoroadamantyl group , a perfluoroadamantylmethyl group, and the like.

In formula (a4-3), L ⁵ is preferably an ethylene group.
The divalent saturated hydrocarbon group of A ^f13 is preferably a group containing a divalent chain hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. A 2-3 divalent chain hydrocarbon group is more preferred.
The saturated hydrocarbon group of A ^f14 is preferably a group containing a chain hydrocarbon group having 3 to 12 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a chain hydrocarbon group having 3 to 10 carbon atoms. and a group containing an alicyclic hydrocarbon group having 3 to 10 carbon atoms is more preferred. Among them, A ^f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group.

Examples of structural units represented by formula (a4-3) include structural units represented by formulas (a4-1′-1) to (a4-1′-11). A structural unit in which the methyl group corresponding to R ^f7 in the structural unit (a4-3) is replaced with a hydrogen atom is also included as the structural unit represented by the formula (a4-3).

［式（ａ４－４）中、
Ｒ^f21は、水素原子又はメチル基を表す。
Ａ^f21は、－（ＣＨ₂）_j1－、－（ＣＨ₂）_j2－Ｏ－（ＣＨ₂）_j3－又は－（ＣＨ₂）_j4－ＣＯ－Ｏ－（ＣＨ₂）_j5－を表す。
ｊ１～ｊ５は、それぞれ独立に、１～６のいずれかの整数を表す。
Ｒ^f22は、フッ素原子を有する炭素数１～１０の飽和炭化水素基を表す。］ Structural units (a4) also include structural units represented by formula (a4-4).

[In formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 represents -(CH ₂ ) _j1 -, -(CH ₂ ) _j2 -O-(CH ₂ ) _j3 - or -(CH ₂ ) _j4 -CO-O-(CH ₂ ) _j5 -.
j1 to j5 each independently represent an integer of 1 to 6;
R ^f22 represents a C 1-10 saturated hydrocarbon group having a fluorine atom. ]

The saturated hydrocarbon group represented by R ^{f22 includes the same saturated hydrocarbon group represented by R a42 .} R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom. An alkyl group having 1 to 6 carbon atoms and having a fluorine atom is more preferred.
In formula (a4-4), A ^f21 is preferably --(CH ₂ ) _j1 --, more preferably an ethylene group or a methylene group, and still more preferably a methylene group.

As the structural unit represented by formula (a4-4), for example, in structural units represented by the following structural units and structural units represented by the following formulas, the methyl group corresponding to R ^f21 in structural unit (a4-4) is hydrogen Structural units replaced with atoms are included.

When the resin (A) has the structural unit (a4), the content thereof is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, based on the total structural units of the resin (A), and 3 ~10 mol% is more preferred.

［式（ａ５－１）中、
Ｒ⁵¹は、水素原子又はメチル基を表す。
Ｒ⁵²は、炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる水素原子は炭素数１～８の脂肪族炭化水素基で置換されていてもよい。
Ｌ⁵⁵は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。］ <Structural unit (a5)>
Examples of non-leaving hydrocarbon groups possessed by the structural unit (a5) include groups having linear, branched or cyclic hydrocarbon groups. Among them, the structural unit (a5) is preferably a group having an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include structural units represented by formula (a5-1).

[In the formula (a5-1),
^R51 represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. .
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O— or —CO— . ]

式（Ｌ１－１）中、
Ｘ^x1は、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＬ^ｘ１との結合位を表す。）。
Ｌ^x1は、炭素数１～１６の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x2は、単結合又は炭素数１～１５の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x1及びＬ^x2の合計炭素数は、１６以下である。
式（Ｌ１－２）中、
Ｌ^x3は、炭素数１～１７の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x4は、単結合又は炭素数１～１６の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x3及びＬ^x4の合計炭素数は、１７以下である。
式（Ｌ１－３）中、
Ｌ^x5は、炭素数１～１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x6及びＬ^x7は、それぞれ独立に、単結合又は炭素数１～１４の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x5、Ｌ^x6及びＬ^x7の合計炭素数は、１５以下である。
式（Ｌ１－４）中、
Ｌ^x8及びＬ^x9は、単結合又は炭素数１～１２の２価の脂肪族飽和炭化水素基を表す。
Ｗ^x1は、炭素数３～１５の２価の脂環式飽和炭化水素基を表す。
ただし、Ｌ^x8、Ｌ^x9及びＷ^x1の合計炭素数は、１５以下である。
Ｌ^x1は、好ましくは、炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、メチレン基又はエチレン基である。
Ｌ^x2は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、単結合である。
Ｌ^x3は、好ましくは、炭素数１～８の２価の脂肪族飽和炭化水素基である。
Ｌ^x4は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基である。
Ｌ^x5は、好ましくは、炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、メチレン基又はエチレン基である。
Ｌ^x6は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、メチレン基又はエチレン基である。
Ｌ^x7は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基である。
Ｌ^x8は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、単結合又はメチレン基である。
Ｌ^x9は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、単結合又はメチレン基である。
Ｗ^x1は、好ましくは、炭素数３～１０の２価の脂環式飽和炭化水素基、より好ましくは、シクロヘキサンジイル基又はアダマンタンジイル基である。 The alicyclic hydrocarbon group for R ⁵² may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl groups. Examples of polycyclic alicyclic hydrocarbon groups include adamantyl groups and norbornyl groups.
Aliphatic hydrocarbon groups having 1 to 8 carbon atoms are, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 - alkyl groups such as ethylhexyl groups.
A 3-methyladamantyl group etc. are mentioned as an alicyclic hydrocarbon group which has a substituent.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.
The divalent saturated hydrocarbon group for L ⁵⁵ includes a divalent saturated chain hydrocarbon group and a saturated divalent alicyclic hydrocarbon group, preferably a saturated chain divalent hydrocarbon group. .
Examples of divalent chain saturated hydrocarbon groups include alkanediyl groups such as methylene, ethylene, propanediyl, butanediyl and pentanediyl groups.
The bivalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. The monocyclic alicyclic saturated hydrocarbon group includes cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.
Groups in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ⁵⁵ is replaced with —O— or —CO— include, for example, formulas (L1-1) to (L1-4) and the group represented by In the following formula, * represents a bonding position with an oxygen atom.

In formula (L1-1),
X ^x1 represents *-O-CO- or *-CO-O- (* represents the bonding position with L ^x1 ).
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.
In formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent saturated aliphatic hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^x5 , L ^x6 and L ^x7 is 15 or less.
In formula (L1-4),
L ^x8 and L ^x9 each represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent saturated alicyclic hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of L ^x8 , L ^x9 and W ^x1 is 15 or less.
L ^x1 is preferably a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a single bond.
L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent saturated alicyclic hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

Examples of the group represented by formula (L1-1) include the divalent groups shown below.

Examples of the group represented by formula (L1-2) include the divalent groups shown below.

Examples of the group represented by formula (L1-3) include the divalent groups shown below.

Ｌ⁵⁵は、好ましくは、単結合又は式（Ｌ１－１）で表される基である。 Examples of the group represented by formula (L1-4) include the divalent groups shown below.

L ⁵⁵ is preferably a single bond or a group represented by formula (L1-1).

Examples of the structural unit (a5-1) include the structural units shown below and structural units in which the methyl group corresponding to R ⁵¹ in the structural unit (a5-1) in the following structural units is replaced with a hydrogen atom.

樹脂（Ａ）が、構造単位（ａ５）を有する場合、その含有率は、樹脂（Ａ）の全構造単位に対して、１～３０モル％が好ましく、２～２０モル％がより好ましく、３～１５モル％がさらに好ましい。

When the resin (A) has the structural unit (a5), the content thereof is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, based on the total structural units of the resin (A), and 3 ~15 mol% is more preferred.

［式（ＩＩ－２－Ａ’）中、
Ｘ^ＩＩＩ３は、炭素数１～１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、ハロゲン原子、ハロゲン原子を有していてもよい炭素数１～６のアルキル基又はヒドロキシ基で置き換わっていてもよい。
Ａ^ｘ１は、炭素数１～８のアルカンジイル基を表し、該アルカンジイル基に含まれる水素原子は、フッ素原子又は炭素数１～６のペルフルオロアルキル基で置換されていてもよい。
ＲＡ^－は、スルホナート基又はカルボキシレート基を表す。
Ｒ^ＩＩＩ３は、水素原子、ハロゲン原子又はハロゲン原子を有していてもよい炭素数１～６のアルキル基を表す。
ＺＡ^＋は、有機カチオンを表す。］ <Structural unit (II)>
The resin (A) may further contain a structural unit that is decomposed by exposure to generate an acid (hereinafter sometimes referred to as "structural unit (II)"). includes structural units described in JP-A-2016-79235, a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or a structural unit having a sulfonio group and an organic anion in the side chain. Preferably.
A structural unit having a sulfonate group or carboxylate group and an organic cation in a side chain is preferably a structural unit represented by formula (II-2-A').

[In the formula (II-2-A '),
X ^III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O—, —S— or —CO— A hydrogen atom contained in the saturated hydrocarbon group may be replaced with a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, or a hydroxy group.
A ^x1 represents an alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
RA- represents a sulfonate group ^or a carboxylate group.
R ^III3 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
ZA ⁺ represents an organic cation. ]

Halogen atoms represented by R ^III3 include fluorine, chlorine, bromine and iodine atoms.
The alkyl group having 1 to 6 carbon atoms and optionally having a halogen atom represented by R ^III3 includes an alkyl group having 1 to 6 carbon atoms and optionally having a halogen atom represented by R ^a8 . The same can be mentioned.
The alkanediyl group having 1 to 8 carbon atoms represented by A ^x1 includes methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group and pentane-1,5-diyl group. , hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2, 4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. mentioned.
Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X ^III3 include a linear or branched alkanediyl group and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. and may be a combination of these.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 ,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , dodecane-1,12-diyl group and other linear alkanediyl groups; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group , pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group and other branched alkanediyl groups; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 ,4-diyl group, cycloalkanediyl group such as cyclooctane-1,5-diyl group; norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane Divalent polycyclic alicyclic saturated hydrocarbon groups such as -2,6-diyl group and the like can be mentioned.
Examples of saturated hydrocarbon groups in which —CH ₂ — is replaced with —O—, —S— or —CO— include divalent groups represented by formulas (X1) to (X53). mentioned. However, -CH ₂ - contained in the saturated hydrocarbon group has 17 or less carbon atoms before being replaced with -O-, -S- or -CO-. In the following formula, * represents the bonding position with A ^x1 .

X ³ represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms.
X ⁴ represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
X ⁵ represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
X ⁶ represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
X ⁷ represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms.
X ⁸ represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

Examples of the organic cation represented by ZA ⁺ include those similar to Z ⁺ in the acid generator represented by formula (B1) described below.

［式（ＩＩ－２－Ａ）中、Ｒ^ＩＩＩ３、Ｘ^ＩＩＩ３及びＺＡ^＋は、上記と同じ意味を表す。
Ｚは、０～６のいずれかの整数を表す。
Ｒ^ＩＩＩ２及びＲ^ＩＩＩ４は、それぞれ独立して、水素原子、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表し、ｚが２以上のとき、複数のＲ^ＩＩＩ２及びＲ^ＩＩＩ４は互いに同一であってもよいし、異なっていてもよい。
Ｑ^ａ及びＱ^ｂは、それぞれ独立して、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。］ The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A).

[In formula (II-2-A), R ^III3 , X ^III3 and ZA ⁺ have the same meanings as above.
Z represents any integer from 0 to 6.
R ^III2 and R ^III4 each independently represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms, and when z is 2 or more, a plurality of R ^III2 and R ^III4 are the same may be different.
Q ^a and Q ^b each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group. ]

Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by R ^III2 , R ^III4 , Q ^a and Q ^b include the same perfluoroalkyl groups having 1 to 6 carbon atoms represented by Q ^b1 described above. .

［式（ＩＩ－２－Ａ－１）中、
Ｒ^ＩＩＩ２、Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ４、Ｑ^a、Ｑ^b、ｚ及びＺＡ^＋は、上記と同じ意味を表す。
Ｒ^ＩＩＩ５は、炭素数１～１２の飽和炭化水素基を表す。
Ｘ^Ｉ2は、炭素数１～１１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、ハロゲン原子又はヒドロキシ基で置換されていてもよい。］ The structural unit represented by formula (II-2-A) is preferably a structural unit represented by formula (II-2-A-1).

[In formula (II-2-A-1),
R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b , z and ZA ⁺ have the same meanings as above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
X ^I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O—, —S— or —CO—. A hydrogen atom contained in the saturated hydrocarbon group may be substituted with a halogen atom or a hydroxy group. ]

Examples of saturated hydrocarbon groups having 1 to 12 carbon atoms represented by R ^III5 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Linear or branched alkyl groups such as heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group can be mentioned.
The divalent saturated hydrocarbon group represented by X ^I2 includes the same divalent saturated hydrocarbon groups as those represented by X ^III3 .

［式（ＩＩ－２－Ａ－２）中、Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ５及びＺＡ^＋は、上記と同じ意味を表す。
ｍ及びｎは、それぞれ独立に、１又は２を表す。］ As the structural unit represented by formula (II-2-A-1), a structural unit represented by formula (II-2-A-2) is preferable.

[In formula (II-2-A-2), R ^III3 , R ^III5 and ZA ⁺ have the same meanings as above.
m and n each independently represent 1 or 2; ]

The structural unit represented by formula (II-2-A′) includes, for example, the following structural units and structural units described in International Publication No. 2012/050015. ZA ⁺ represents an organic cation.

［式（ＩＩ－１－１）中、
Ａ^ＩＩ１は、単結合又は２価の連結基を表す。
Ｒ^ＩＩ１は、炭素数６～１８の２価の芳香族炭化水素基を表す。
Ｒ^ＩＩ２及びＲ^ＩＩ３は、それぞれ独立して、炭素数１～１８の炭化水素基を表し、Ｒ^ＩＩ２及びＲ^ＩＩ３は互いに結合してそれらが結合する硫黄原子とともに環を形成していてもよい。
Ｒ^II4は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１～６のアルキル基を表す。
Ａ^－は、有機アニオンを表す。］
Ｒ^ＩＩ１で表される炭素数６～１８の２価の芳香族炭化水素基としては、フェニレン基及びナフチレン基等が挙げられる。
Ｒ^ＩＩ２及びＲ^ＩＩ３で表される炭化水素基としては、アルキル基、脂環式炭化水素基、芳香族炭化水素基及びこれらを組み合わせることにより形成される基等が挙げられる。
Ｒ^ＩＩ４で表されるハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子等が挙げられる。
Ｒ^ＩＩ４で表されるハロゲン原子を有していてもよい炭素数１～６のアルキル基としては、Ｒ^ａ８で表されるハロゲン原子を有していてもよい炭素数１～６のアルキル基と同じものが挙げられる。
Ａ^ＩＩ１で表される２価の連結基としては、例えば、炭素数１～１８の２価の飽和炭化水素基が挙げられ、該２価の飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－又は－ＣＯ－で置き換わっていてもよい。具体的には、Ｘ^ＩＩＩ３で表される炭素数１～１８の２価の飽和炭化水素基と同じものが挙げられる。 A structural unit having a sulfonio group and an organic anion in a side chain is preferably a structural unit represented by formula (II-1-1).

[In the formula (II-1-1),
^AII1 represents a single bond or a divalent linking group.
R ^II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^II2 and R ^II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and R ^II2 and R ^II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
R ^II4 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
A ⁻ represents an organic anion. ]
Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ^II1 include a phenylene group and a naphthylene group.
The hydrocarbon groups represented by R ^II2 and R ^II3 include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and groups formed by combining these groups.
Halogen atoms represented by ^RII4 include fluorine, chlorine, bromine and iodine atoms.
The alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^II4 includes an alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 . The same can be mentioned.
The divalent linking group represented by A ^II1 includes, for example, a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is -O-, -S- or -CO- may be substituted. Specific examples thereof include the same divalent saturated hydrocarbon groups having 1 to 18 carbon atoms represented by X ^III3 .

Examples of structural units containing cations in formula (II-1-1) include structural units represented below.

Organic anions represented by A ⁻ include sulfonate anions, sulfonylimide anions, sulfonylmethide anions and carboxylate anions. The organic anion represented by A ⁻ is preferably a sulfonate anion, and the sulfonate anion is more preferably an anion contained in a salt represented by formula (B1) described later.

Sulfonylimide anions represented by A ⁻ include the following.

Sulfonylmethide anions include the following.

Carboxylate anions include the following.

Examples of structural units represented by formula (II-1-1) include structural units represented below.

When the resin (A) contains the structural unit (II), the content of the structural unit (II) is preferably 1 to 20 mol% of the total structural units of the resin (A), and more It is preferably 2 to 15 mol %, more preferably 3 to 10 mol %.

Resin (A) may have structural units other than the structural units described above, and examples of such structural units include structural units well known in the art.
Resin (A) is preferably a resin comprising structural unit (I), structural unit (a1-1) and structural unit (a1-2), structural unit (I), structural unit (a1-1) and structural unit (a1-2) and a structural unit (s), a structural unit (I), a structural unit (a1-1), a structural unit (a1-2), a structural unit (s), a structural unit (a4), and / or a resin consisting of the structural unit (a5), more preferably a resin consisting of the structural unit (I), the structural unit (a1-1), the structural unit (a1-2), and the structural unit (s) be.
Structural unit (s) is preferably at least one selected from the group consisting of structural unit (a2) and structural unit (a3). Structural unit (a2) is preferably structural unit (a2-1) or structural unit (a2-A). Structural unit (a3) is preferably a group consisting of a structural unit represented by formula (a3-1), a structural unit represented by formula (a3-2) and a structural unit represented by formula (a3-4) is at least one selected from

Each structural unit that constitutes the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (e.g., radical polymerization method) using a monomer that leads to these structural units. be able to. The content of each structural unit in the resin (A) can be adjusted by adjusting the amount of monomer used for polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, further preferably 15,000 or less).
As used herein, the weight average molecular weight is a value determined by gel permeation chromatography. Gel permeation chromatography can be measured under the analysis conditions described in Examples.

[Resist composition]
The resist composition of the present invention preferably contains a resin (A) and an acid generator known in the resist field (hereinafter sometimes referred to as "acid generator (B)").
The resist composition of the present invention preferably further contains a resin other than resin (A).
The resist composition of the present invention preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") such as a salt that generates an acid that is weaker in acidity than the acid generated by the acid generator. , a solvent (hereinafter sometimes referred to as "solvent (E)").

<Resins other than resin (A)>
Resins other than the resin (A) may be resins that do not contain the structural unit (I). Examples of such a resin include, for example, a resin obtained by removing the structural unit (I) from the resin (A) (hereinafter sometimes referred to as "resin (A2)"), and only the structural unit (a4) and the structural unit (a5). (hereinafter sometimes referred to as resin (X)) and the like.
As the resin (X), among others, a resin containing the structural unit (a4) (but not containing the structural unit (I)) is preferable.
In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, based on the total of all structural units of the resin (X). , more preferably 45 mol % or more.
Structural units that the resin (X) may further include structural units (a1), structural units (a2), structural units (a3), and structural units derived from other known monomers. Among them, the resin (X) is preferably a resin consisting only of the structural unit (a4) and/or the structural unit (a5), more preferably a resin consisting only of the structural unit (a4).
Each structural unit that constitutes the resin (X) may be used alone or in combination of two or more. Using a monomer that induces these structural units, the resin (X) is produced by a known polymerization method (e.g., radical polymerization method). can do. The content of each structural unit in the resin (X) can be adjusted by adjusting the amount of the monomer used for polymerization.
The weight average molecular weights of resin (A2) and resin (X) are each independently preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). be. The means for measuring the weight average molecular weights of resin (A2) and resin (X) is the same as in the case of resin (A).
When the resist composition of the present invention contains the resin (A2), its content is usually 1 to 2500 parts by mass (more preferably 10 to 1000 parts by mass) with respect to 100 parts by mass of the resin (A). be.
Further, when the resist composition contains the resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, relative to 100 parts by mass of the resin (A). , More preferably 1 to 40 parts by mass, particularly preferably 1 to 30 parts by mass, particularly preferably 1 to 8 parts by mass.

The resin (A) content in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90 to 99% by mass, based on the solid content of the resist composition. Further, when a resin other than the resin (A) is included, the total content of the resin (A) and the resin other than the resin (A) is 80% by mass or more and 99% by mass with respect to the solid content of the resist composition. It is preferably below, more preferably 90 to 99% by mass. The solid content and resin content of the resist composition can be measured by known analytical means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
The acid generator (B) may be either nonionic or ionic. Nonionic acid generators include sulfonate esters (eg 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (eg disulfone, ketosulfone, sulfonyldiazomethane) and the like. Typical ionic acid generators are onium salts containing onium cations (eg, diazonium salts, phosphonium salts, sulfonium salts and iodonium salts). The anions of the onium salts include sulfonate anions, sulfonylimide anions, sulfonylmethide anions, and the like.
Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. A compound that generates an acid upon exposure to radiation as described in 1. above can be used. Moreover, you may use the compound manufactured by the well-known method. The acid generator (B) may be used in combination of two or more.

［式（Ｂ１）中、
Ｑ^ｂ１及びＱ^ｂ２は、それぞれ独立に、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｌ^ｂ１は、炭素数１～２４の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ（Ｏ）_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］
Ｌ^ｂ１において、２価の飽和炭化水素基に含まれる少なくとも１つの－ＣＨ_２－は、－－ＣＯ－に置き換わっていることが好ましい。
Ｙは、置換基を有していてもよい炭素数３～１８の脂環式炭化水素基であることが好ましい。 The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)").

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO— , a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S(O) ₂ - or -CO-.
Z ⁺ represents an organic cation. ]
In L ^b1 , at least one —CH ₂ — contained in the divalent saturated hydrocarbon group is preferably replaced with —CO—.
Y is preferably an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms.

The perfluoroalkyl groups represented by Q ^b1 and Q ^b2 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and A perfluorohexyl group and the like can be mentioned.
Q ^b1 and Q ^b2 are each independently preferably a fluorine atom or a trifluoromethyl group, more preferably both a fluorine atom.

The divalent saturated hydrocarbon group for L ^b1 includes a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic bivalent alicyclic saturated hydrocarbon group, and these A group formed by combining two or more of the groups may also be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 ,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group , tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group. alkanediyl group;
ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group;
monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group and the like.

Groups in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with —O— or —CO— include, for example, formulas (b1-1) to (b1-3) A group represented by any one of is mentioned. In the groups represented by formulas (b1-1) to (b1-3) and formulas (b1-4) to (b1-11) which are specific examples thereof, * is a bond with -Y represents

［式（ｂ１－１）中、
Ｌ^ｂ２は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ３は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ただし、Ｌ^ｂ２とＬ^ｂ３との炭素数合計は、２２以下である。
式（ｂ１－２）中、
Ｌ^ｂ４は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ５は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ただし、Ｌ^ｂ４とＬ^ｂ５との炭素数合計は、２２以下である。
式（ｂ１－３）中、
Ｌ^ｂ６は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
Ｌ^ｂ７は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ただし、Ｌ^ｂ６とＬ^ｂ７との炭素数合計は、２３以下である。］

[In formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—.
However, the total number of carbon atoms of L ^b2 and L ^b3 is 22 or less.
In formula (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—.
However, the total number of carbon atoms of L ^b4 and L ^b5 is 22 or less.
In formula (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—.
However, the total number of carbon atoms of L ^b6 and L ^b7 is 23 or less. ]

In the groups represented by formulas (b1-1) to (b1-3), when —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O— or —CO—, carbon before replacement Let the number be the number of carbon atoms of the saturated hydrocarbon group.
As the divalent saturated hydrocarbon group, the same divalent saturated hydrocarbon group as L ^b1 can be mentioned.

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group; —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.
The group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with —O— or —CO— is represented by formula (b1-1) or formula (b1-3). are preferred.

［式（ｂ１－４）中、
Ｌ^ｂ８は、単結合又は炭素数１～２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
式（ｂ１－５）中、
Ｌ^ｂ９は、炭素数１～２０の２価の飽和炭化水素基を表す。
Ｌ^ｂ１０は、単結合又は炭素数１～１９の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ９及びＬ^ｂ１０の合計炭素数は２０以下である。
式（ｂ１－６）中、
Ｌ^ｂ１１は、炭素数１～２１の２価の飽和炭化水素基を表す。
Ｌ^ｂ１２は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１１及びＬ^ｂ１２の合計炭素数は２１以下である。
式（ｂ１－７）中、
Ｌ^ｂ１３は、炭素数１～１９の２価の飽和炭化水素基を表す。
Ｌ^ｂ１４は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１５は、単結合又は炭素数１～１８の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１３～Ｌ^ｂ１５の合計炭素数は１９以下である。
式（ｂ１－８）中、
Ｌ^ｂ１６は、炭素数１～１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１７は、炭素数１～１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１８は、単結合又は炭素数１～１７の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１６～Ｌ^ｂ１８の合計炭素数は１９以下である。］ Examples of the group represented by formula (b1-1) include groups represented by formulas (b1-4) to (b1-8).

[In formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In formula (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b9 and L ^b10 is 20 or less.
In formula (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b11 and L ^b12 is 21 or less.
In formula (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b13 to L ^b15 is 19 or less.
In formula (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b16 to L ^b18 is 19 or less. ]

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a C 1-19 divalent saturated hydrocarbon group, more preferably a single bond or a C 1-8 divalent saturated hydrocarbon group.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a C 1-18 divalent saturated hydrocarbon group, more preferably a single bond or a C 1-8 divalent saturated hydrocarbon group.
L ^b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b18 is preferably a single bond or a C 1-17 divalent saturated hydrocarbon group, more preferably a single bond or a C 1-4 divalent saturated hydrocarbon group.

式（ｂ１－９）中、
Ｌ^b19は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b20は、単結合又は炭素数１～２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b19及びＬ^b20の合計炭素数は２３以下である。
式（ｂ１－１０）中、
Ｌ^b21は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b22は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表す。
Ｌ^b23は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b21、Ｌ^b22及びＬ^b23の合計炭素数は２１以下である。
式（ｂ１－１１）中、
Ｌ^b24は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b25は、炭素数１～２１の２価の飽和炭化水素基を表す。
Ｌ^b26は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b24、Ｌ^b25及びＬ^b26の合計炭素数は２１以下である。 Examples of the group represented by formula (b1-3) include groups represented by formulas (b1-9) to (b1-11).

In formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group being substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group; good too. --CH ₂ -- contained in the alkylcarbonyloxy group may be replaced with --O-- or --CO--, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In formula (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group; good too. --CH ₂ -- contained in the alkylcarbonyloxy group may be replaced with --O-- or --CO--, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b21 , L ^b22 and L ^b23 is 21 or less.
In formula (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group; good too. --CH ₂ -- contained in the alkylcarbonyloxy group may be replaced with --O-- or --CO--, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b24 , L ^b25 and L ^b26 is 21 or less.

In addition, in the group represented by formula (b1-9) to the group represented by formula (b1-11), when the hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, it is replaced Let the previous carbon number be the carbon number of this saturated hydrocarbon group.
The alkylcarbonyloxy group includes an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, an adamantylcarbonyloxy group and the like.

Examples of the group represented by formula (b1-4) include the following.

Examples of the group represented by formula (b1-5) include the following.

Examples of the group represented by formula (b1-6) include the following.

Examples of the group represented by formula (b1-7) include the following.

Examples of the group represented by formula (b1-8) include the following.

Examples of the group represented by formula (b1-2) include the following.

Examples of the group represented by formula (b1-9) include the following.

Examples of the group represented by formula (b1-10) include the following.

Examples of the group represented by formula (b1-11) include the following.

The alicyclic hydrocarbon group represented by Y includes groups represented by formulas (Y1) to (Y11) and formulas (Y36) to (Y38).
When —CH ₂ — contained in the alicyclic hydrocarbon group represented by Y is replaced with —O—, —S(O) ₂ — or —CO—, the number may be 1 or 2 or more. good. Such groups include groups represented by formulas (Y12) to (Y35) and formulas (Y39) to (Y41).

Ｙとしては、好ましくは式（Ｙ１）～式（Ｙ２０）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）～式（Ｙ４１）のいずれかで表される基であり、より好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ１６）、式（Ｙ２０）、式（Ｙ３０）、式（Ｙ３１））、式（Ｙ３９）又は式（Ｙ４０）で表される基であり、さらに好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ３０））、式（Ｙ３９）又は式（Ｙ４０）で表される基である。
Ｙが式（Ｙ２８）～式（Ｙ３５）等のスピロ環である場合には、２つの酸素原子間のアルカンジイル基は、１以上のフッ素原子を有することが好ましい。また、ケタール構造に含まれるアルカンジイル基のうち、酸素原子に隣接するメチレン基には、フッ素原子が置換されていないのが好ましい。

Y is preferably a group represented by any one of formula (Y1) to formula (Y20), formula (Y30), formula (Y31), formula (Y39) to formula (Y41), more preferably formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y30), formula (Y31)), formula (Y39) or a group represented by formula (Y40), more preferably a group represented by formula (Y11), formula (Y15), formula (Y30)), formula (Y39) or formula (Y40);
When Y is a spiro ring such as formulas (Y28) to (Y35), the alkanediyl group between two oxygen atoms preferably has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, the methylene group adjacent to the oxygen atom is preferably not substituted with a fluorine atom.

Examples of substituents of the methyl group represented by Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, or -( CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms) represents a hydrocarbon group, and ja represents an integer of 0 to 4), and the like.
Substituents for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms optionally substituted by a hydroxy group, and an alicyclic group having 3 to 16 carbon atoms. a hydrocarbon group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, a glycidyloxy group or -( CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms) represents a hydrocarbon group, and ja represents an integer of 0 to 4), and the like.
Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
Examples of alicyclic hydrocarbon groups include cyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl, cyclooctyl, norbornyl and adamantyl groups.
Examples of aromatic hydrocarbon groups include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group and mesityl group. , a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and an aryl group such as 2-methyl-6-ethylphenyl.
Examples of alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group and nonyl. group, decyl group, undecyl group, dodecyl group and the like.
Alkyl groups substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups.
Aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl and naphthylethyl groups.
Examples of alkylcarbonyl groups include acetyl group, propionyl group and butyryl group.

Examples of Y include the following.

Y is preferably an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an optionally substituted adamantyl group, and the alicyclic carbonization —CH ₂ — constituting a hydrogen group or an adamantyl group may be replaced with —CO—, —S(O) ₂ — or —CO—. Y is more preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, or a group represented below.

Examples of the sulfonate anion in the acid generator (B1) include anions represented by formulas (B1-A-1) to (B1-A-55) [hereinafter referred to as "anions (B1-A- 1)”, etc. ] is preferable, formula (B1-A-1) ~ formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) ~ formula (B1-A-33), formula (B1-A-36) ~ formula (B1-A-40), represented by any of formula (B1-A-47) ~ formula (B1-A-55) Anions are more preferred.

ここでＲ^ｉ２～Ｒ^ｉ７は、それぞれ独立に、例えば、炭素数１～４のアルキル基、好ましくはメチル基又はエチル基である。Ｒ^ｉ８は、例えば、炭素数１～１２の脂肪族炭化水素基、好ましくは炭素数１～４のアルキル基、炭素数５～１２の脂環式炭化水素基又はこれらを組合せることにより形成される基、より好ましくはメチル基、エチル基、シクロヘキシル基又はアダマンチル基である。Ｌ^Ａ４は、単結合又は炭素数１～４のアルカンジイル基である。
Ｑ^ｂ１及びＱ^ｂ２は、上記と同じ意味を表す。
酸発生剤（Ｂ１）におけるスルホン酸アニオンとしては、具体的には、特開２０１０－２０４６４６号公報に記載されたアニオンが挙げられる。

Here, R ⁱ² to R ⁱ⁷ are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. group, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L ^A4 is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ^b1 and Q ^b2 have the same meanings as above.
Specific examples of the sulfonate anion in the acid generator (B1) include anions described in JP-A-2010-204646.

Preferred sulfonate anions in the acid generator (B1) include anions represented by formulas (B1a-1) to (B1a-34).

Among them, formula (B1a-1) ~ formula (B1a-3) and formula (B1a-7) ~ formula (B1a-16), formula (B1a-18), formula (B1a-19), formula (B1a-22 ) to formula (B1a-34) are preferred.

Organic cations of Z ⁺ include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, organic phosphonium cations, and the like. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, a cation represented by any one of formulas (b2-1) to (b2-4) (hereinafter sometimes referred to as "cation (b2-1)" etc. depending on the formula number) is mentioned.

式（ｂ２－１）～式（ｂ２－４）において、
Ｒ^b4～Ｒ^b6は、それぞれ独立に、炭素数１～３０の鎖式炭化水素基、炭素数３～３６の脂環式炭化水素基又は炭素数６～３６の芳香族炭化水素基を表し、該鎖式炭化水素基に含まれる水素原子は、ヒドロキシ基、炭素数１～１２のアルコキシ基、炭素数３～１２の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基で置換されていてもよく、該脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、炭素数１～１８の脂肪族炭化水素基、炭素数２～４のアルキルカルボニル基又はグリシジルオキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基又は炭素数１～１２のアルコキシ基で置換されていてもよい。
Ｒ^b4とＲ^b5とは、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b7及びＲ^b8は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
ｍ２及びｎ２は、それぞれ独立に０～５のいずれかの整数を表す。
ｍ２が２以上のとき、複数のＲ^b7は同一でも異なってもよく、ｎ２が２以上のとき、複数のＲ^b8は同一でも異なってもよい。
Ｒ^b9及びＲ^b10は、それぞれ独立に、炭素数１～３６の鎖式炭化水素基又は炭素数３～３６の脂環式炭化水素基を表す。
Ｒ^b9とＲ^b10とは、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b11は、水素原子、炭素数１～３６の鎖式炭化水素基、炭素数３～３６の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基を表す。
Ｒ^b12は、炭素数１～１２の鎖式炭化水素基、炭素数３～１８の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基を表し、該鎖式炭化水素に含まれる水素原子は、炭素数６～１８の芳香族炭化水素基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、炭素数１～１２のアルコキシ基又は炭素数１～１２のアルキルカルボニルオキシ基で置換されていてもよい。
Ｒ^b11とＲ^b12とは、互いに結合してそれらが結合する－ＣＨ－ＣＯ－を含めて環を形成していてもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b13～Ｒ^b18は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
Ｌ^b31は、硫黄原子又は酸素原子を表す。
ｏ２、ｐ２、ｓ２、及びｔ２は、それぞれ独立に、０～５のいずれかの整数を表す。
ｑ２及びｒ２は、それぞれ独立に、０～４のいずれかの整数を表す。
ｕ２は０又は１を表す。
ｏ２が２以上のとき、複数のＲ^b13は同一又は相異なり、ｐ２が２以上のとき、複数のＲ^b14は同一又は相異なり、ｑ２が２以上のとき、複数のＲ^b15は同一又は相異なり、ｒ２が２以上のとき、複数のＲ^b16は同一又は相異なり、ｓ２が２以上のとき、複数のＲ^b17は同一又は相異なり、ｔ２が２以上のとき、複数のＲ^b18は同一又は相異なる。
脂肪族炭化水素基とは、鎖式炭化水素基及び脂環式炭化水素基を表す。
鎖式炭化水素基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、ｓｅｃ－ブチル基、ｔｅｒｔ－ブチル基、ペンチル基、ヘキシル基、オクチル基及び２－エチルヘキシル基のアルキル基が挙げられる。
特に、Ｒ^b9～Ｒ^b12の鎖式炭化水素基は、好ましくは炭素数１～１２である。
脂環式炭化水素基としては、単環式又は多環式のいずれでもよく、単環式の脂環式炭化水素基としては、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロへキシル基、シクロヘプチル基、シクロオクチル基、シクロデシル基等のシクロアルキル基が挙げられる。多環式の脂環式炭化水素基としては、デカヒドロナフチル基、アダマンチル基、ノルボルニル基及び下記の基等が挙げられる。

特に、Ｒ^b9～Ｒ^b12の脂環式炭化水素基は、好ましくは炭素数３～１８、より好ましくは炭素数４～１２である。
水素原子が脂肪族炭化水素基で置換された脂環式炭化水素基としては、メチルシクロヘキシル基、ジメチルシクロへキシル基、２－メチルアダマンタン－２－イル基、２－エチルアダマンタン－２－イル基、２－イソプロピルアダマンタン－２－イル基、メチルノルボルニル基、イソボルニル基等が挙げられる。水素原子が脂肪族炭化水素基で置換された脂環式炭化水素基においては、脂環式炭化水素基と脂肪族炭化水素基との合計炭素数が好ましくは２０以下である。
芳香族炭化水素基としては、フェニル基、トリル基、キシリル基、クメニル基、メシチル基、ｐ－エチルフェニル基、ｐ－ｔｅｒｔ－ブチルフェニル基、ｐ－シクロへキシルフェニル基、ｐ－アダマンチルフェニル基、ビフェニリル基、ナフチル基、フェナントリル基、２，６－ジエチルフェニル基、２－メチル－６－エチルフェニル基等のアリール基が挙げられる。
なお、芳香族炭化水素基に、鎖式炭化水素基又は脂環式炭化水素基が含まれる場合は、炭素数１～１８の鎖式炭化水素基及び炭素数３～１８の脂環式炭化水素基が好ましい。
水素原子がアルコキシ基で置換された芳香族炭化水素基としては、ｐ－メトキシフェニル基等が挙げられる。
水素原子が芳香族炭化水素基で置換された鎖式炭化水素基としては、ベンジル基、フェネチル基、フェニルプロピル基、トリチル基、ナフチルメチル基、ナフチルエチル基等のアラルキル基が挙げられる。
アルコキシ基としては、メトキシ基、エトキシ基、プロポキシ基、ブトキシ基、ペンチルオキシ基、ヘキシルオキシ基、ヘプチルオキシ基、オクチルオキシ基、デシルオキシ基及びドデシルオキシ基等が挙げられる。
アルキルカルボニル基としては、アセチル基、プロピオニル基及びブチリル基等が挙げられる。
ハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子等が挙げられる。
アルキルカルボニルオキシ基としては、メチルカルボニルオキシ基、エチルカルボニルオキシ基、プロピルカルボニルオキシ基、イソプロピルカルボニルオキシ基、ブチルカルボニルオキシ基、ｓｅｃ－ブチルカルボニルオキシ基、ｔｅｒｔ－ブチルカルボニルオキシ基、ペンチルカルボニルオキシ基、ヘキシルカルボニルオキシ基、オクチルカルボニルオキシ基及び２－エチルヘキシルカルボニルオキシ基等が挙げられる。
Ｒ^b4とＲ^b5とが互いに結合してそれらが結合する硫黄原子と一緒になって形成する環は、単環式、多環式、芳香族性、非芳香族性、飽和及び不飽和のいずれの環であってもよい。この環は、炭素数３～１８の環が挙げられ、好ましくは炭素数４～１８の環である。また、硫黄原子を含む環は、３員環～１２員環が挙げられ、好ましくは３員環～７員環であり、例えば下記の環が挙げられる。

In formulas (b2-1) to (b2-4),
R ^b4 to R ^b6 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 36 carbon atoms; The hydrogen atom contained in the chain hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. It may be substituted, and the hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group. It may be substituted, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S— or -CO- may be substituted.
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5;
When m2 is 2 or more, multiple R ^b7 may be the same or different, and when n2 is 2 or more, multiple R ^b8 may be the same or different.
R ^b9 and R ^b10 each independently represent a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S— or -CO- may be substituted.
R ^b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atoms contained in the aromatic hydrocarbon group are alkoxy groups having 1 to 12 carbon atoms or 1 to 1 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may be bonded to each other to form a ring including —CH—CO— to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S - or -CO- may be substituted.
R ^b13 to R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5;
q2 and r2 each independently represent an integer of 0 to 4;
u2 represents 0 or 1;
When o2 is 2 or more, multiple R ^b13 are the same or different, when p2 is 2 or more, multiple R ^b14 are the same or different, and when q2 is 2 or more, multiple R ^b15 are the same or different. , when r2 is 2 or more, the plurality of R ^b16 are the same or different; when s2 is 2 or more, the plurality of R ^b17 are the same or different; when t2 is 2 or more, the plurality of R ^b18 are the same or different; different.
An aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group.
Chain hydrocarbon groups include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. mentioned.
In particular, chain hydrocarbon groups of R ^b9 to R ^b12 preferably have 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclo Cycloalkyl groups such as a heptyl group, a cyclooctyl group, and a cyclodecyl group can be mentioned. The polycyclic alicyclic hydrocarbon group includes decahydronaphthyl group, adamantyl group, norbornyl group and the following groups.

In particular, the alicyclic hydrocarbon groups of R ^b9 to R ^b12 preferably have 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.
Alicyclic hydrocarbon groups in which hydrogen atoms are substituted with aliphatic hydrocarbon groups include methylcyclohexyl group, dimethylcyclohexyl group, 2-methyladamantan-2-yl group, and 2-ethyladamantan-2-yl group. , 2-isopropyladamantan-2-yl group, methylnorbornyl group, isobornyl group and the like. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total carbon number of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.
The aromatic hydrocarbon group includes a phenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a p-cyclohexylphenyl group and a p-adamantylphenyl group. , biphenylyl group, naphthyl group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl group.
When the aromatic hydrocarbon group contains a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms groups are preferred.
Aromatic hydrocarbon groups in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group and the like.
Chain hydrocarbon groups in which hydrogen atoms are substituted with aromatic hydrocarbon groups include aralkyl groups such as benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl and naphthylethyl groups.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups.
An acetyl group, a propionyl group, a butyryl group, etc. are mentioned as an alkylcarbonyl group.
Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
The alkylcarbonyloxy group includes a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group and a pentylcarbonyloxy group. , hexylcarbonyloxy group, octylcarbonyloxy group and 2-ethylhexylcarbonyloxy group.
The ring formed by R ^b4 and R ^b5 bonded together with the sulfur atom to which they are bonded may be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. may be a ring of This ring includes a ring having 3 to 18 carbon atoms, preferably a ring having 4 to 18 carbon atoms. Further, the ring containing a sulfur atom includes a 3- to 12-membered ring, preferably a 3- to 7-membered ring, and examples thereof include the following rings.

The ring formed by R ^b9 and R ^b10 together may be a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. This ring includes a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples include thiolan-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, 1,4-oxathian-4-ium ring and the like.
The ring formed by R ^b11 and R ^b12 together may be a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. This ring includes a 3- to 12-membered ring, preferably a 3- to 7-membered ring. oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring, oxoadamantane ring and the like.

Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferred.
Examples of the cation (b2-1) include the following cations.

Examples of the cation (b2-2) include the following cations.

Examples of the cation (b2-3) include the following cations.

Examples of the cation (b2-4) include the following cations.

The acid generator (B) is a combination of the above sulfonate anion and the above organic cation, and these can be combined arbitrarily. As the acid generator (B), preferably formulas (B1a-1) to (B1a-3) and formulas (B1a-7) to (B1a-16), formulas (B1a-18), and formulas (B1a- 19), a combination of an anion represented by any one of formulas (B1a-22) to (B1a-34) and a cation (b2-1) or a cation (b2-3).

The acid generator (B) preferably includes those represented by formulas (B1-1) to (B1-48), respectively. Among them, those containing an arylsulfonium cation are preferred, and formula (B1-1) ~ Formula (B1-3), Formula (B1-5) ~ Formula (B1-7), Formula (B1-11) ~ Formula (B1-14), Formula (B1-20) ~ Formula (B1-26), Those represented by formula (B1-29) and formulas (B1-31) to (B1-48) are particularly preferred.

In the resist composition of the present invention, the content of the acid generator is preferably 1 part by mass or more and 40 parts by mass or less, more preferably 3 parts by mass or more and 35 parts by mass or less, relative to 100 parts by mass of the resin (A). is. The resist composition of the present invention may contain one type of acid generator (B) alone, or may contain a plurality of types.

<Solvent (E)>
The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, more preferably 94% by mass or more and 99% by mass. % or less. The content of the solvent (E) can be measured by known analytical means such as liquid chromatography or gas chromatography.
Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; One kind of the solvent (E) may be used alone, or two or more kinds may be used.

<Quencher (C)>
Examples of the quencher (C) include basic nitrogen-containing organic compounds and salts that generate an acid that is weaker in acidity than the acid generated from the acid generator (B). The content of the quencher (C) is preferably about 0.01 to 5% by mass based on the solid content of the resist composition.
Basic nitrogen-containing organic compounds include amines and ammonium salts. Amines include aliphatic amines and aromatic amines. Aliphatic amines include primary, secondary and tertiary amines.
Amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, tri heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, tri isopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3 , 3′-diethyldiphenylmethane, 2,2′-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethane, 1,2-di(4- pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2-di(4-pyridyloxy ) ethane, di(2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipicolylamine, bipyridine and the like, Aromatic amines such as diisopropylaniline are preferred, and 2,6-diisopropylaniline is more preferred.
Ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethyl ammonium hydroxide, tetra-n-butylammonium salicylate and choline;

The acidity of a salt that generates an acid weaker than the acid generated from the acid generator (B) is indicated by the acid dissociation constant (pKa). The salt that generates an acid weaker in acidity than the acid generated from the acid generator (B) has an acid dissociation constant of -3<pKa, preferably -1<. Salts with pKa<7, more preferably salts with 0<pKa<5.
Examples of the salt that generates an acid weaker in acidity than the acid generated from the acid generator (B) include salts represented by the following formula, and salts represented by the formula (D) described in JP-A-2015-147926. (Hereinafter, it may be referred to as "weak acid inner salt (D)".), and JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502. and salts described in JP-A-2011-191745. The salt that generates an acid weaker in acidity than the acid generated from the acid generator (B) is preferably a weak acid inner salt (D).

The weak acid inner salt (D) includes the following salts.

When the resist composition contains the quencher (C), the content of the quencher (C) is usually 0.01 to 5% by mass, preferably 0.01 to 5% by mass, based on the solid content of the resist composition. 3% by mass.

<Other ingredients>
If necessary, the resist composition of the present invention may contain components other than the components described above (hereinafter sometimes referred to as "other components (F)"). Other components (F) are not particularly limited, and additives known in the field of resists, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc., can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises the resin (A) of the present invention, an acid generator (B), and, if necessary, a resin (A2), a resin (X), a quencher (C) and a solvent (E). and other components (F). The mixing order is arbitrary and not particularly limited. The temperature during mixing can be appropriately selected from 10 to 40° C. depending on the type of resin or the like and the solubility of the resin or the like in the solvent (E). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is also not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) a step of applying the resist composition of the present invention onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) heating the exposed composition layer; and (5) developing the heated composition layer.
The coating of the resist composition on the substrate can be carried out using a commonly used device such as a spin coater. Examples of substrates include inorganic substrates such as silicon wafers. Before applying the resist composition, the substrate may be washed, and an antireflection film or the like may be formed on the substrate.
By drying the applied composition, the solvent is removed and a composition layer is formed. Drying is carried out, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a decompression device. The heating temperature is preferably 50 to 200° C., and the heating time is preferably 10 to 180 seconds. Moreover, the pressure for drying under reduced pressure is preferably about 1 to 1.0×10 ⁵ Pa.
The resulting composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As the exposure light source, a KrF excimer laser (wavelength: 248 nm), an ArF excimer laser (wavelength: 193 nm), an F2 excimer laser ₍ wavelength: 157 nm) that emits a laser beam in the ultraviolet region, a solid-state laser source (YAG or semiconductor laser etc.) and emits harmonic laser light in the far ultraviolet region or vacuum ultraviolet region by wavelength conversion, electron beam, and extreme ultraviolet light (EUV). can be done. In the present specification, these irradiations with radiation may be collectively referred to as "exposure". During exposure, exposure is usually performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.
The exposed composition layer is subjected to a heat treatment (so-called post-exposure bake) in order to promote the deprotection reaction at the acid-labile groups. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C.
The composition layer after heating is usually developed using a developer using a developing device. The developing method includes a dipping method, a paddle method, a spraying method, a dynamic dispensing method, and the like. The development temperature is preferably, for example, 5 to 60° C., and the development time is preferably, for example, 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. Examples thereof include aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline). The alkaline developer may contain a surfactant.
After development, the resist pattern is preferably washed with ultrapure water, and then water remaining on the substrate and pattern is removed.
When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as "organic developer") is used as the developer.
Examples of organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether. ether solvents; amide solvents such as N,N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole;
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably substantially only the organic solvent.
Among them, as the organic developer, a developer containing butyl acetate and/or 2-heptanone is preferable. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially contains butyl acetate and/or 2-heptanone. - more preferably only heptanone.
The organic developer may contain a surfactant. In addition, the organic developer may contain a trace amount of water.
During development, the development may be stopped by replacing the organic developer with a solvent of a different type.
It is preferable to wash the resist pattern after development with a rinsing liquid. The rinse liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent.
After cleaning, it is preferable to remove the rinse liquid remaining on the substrate and pattern.

<Application>
The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure. It is more suitable as a resist composition for electron beam (EB) exposure or as a resist composition for EUV exposure, and is useful for microfabrication of semiconductors.

EXAMPLES The present invention will be described more specifically with reference to examples. In the examples, "%" and "parts" representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value obtained by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min
Detector: RI detector Column temperature: 40°C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)
The structure of the compound was confirmed by measuring the molecular peak using mass spectrometry (LC: Agilent Model 1100, MASS: Agilent Model LC/MSD). In the following examples, the value of this molecular ion peak is indicated by "MASS".

式（Ｉ－２－ａ）で表される化合物５０部、式（Ｉ－２－ｃ）で表される塩８．９７部及びクロロホルム５００部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－２－ｂ）で表される化合物３８．６０部を添加し、さらに、２３℃で１８時間攪拌した。得られた反応マスに、イオン交換水２００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層に１０％炭酸カリウム水溶液３００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を４回繰り返した。得られた有機層を濃縮することにより、式（Ｉ－２－ｄ）で表される化合物４３．６５部を得た。

式（Ｉ－２－ｅ）で表される化合物７５．９２部及び式（Ｉ－２－ｆ）で表される化合物２３．８５部を混合し、２３℃で３０分間攪拌した後、０℃まで冷却した。得られた混合溶液に、テトラヒドロフラン５００部を添加した後、３０分間攪拌し、２３℃まで昇温した。得られた混合物に、式（Ｉ－２－ｄ）で表される化合物３７．５０部を添加し、２３℃で１２時間攪拌した。得られた反応マスを濃縮した後、得られた濃縮残に、酢酸エチル５５０部及びイオン交換水２５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮し、濃縮マスをカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝１／１）分取することにより、式（Ｉ－２）で表される化合物１５．２８部を得た。
ＭＡＳＳ：２１１．１ ［Ｍ＋Ｈ］^＋ Synthesis Example 1: Synthesis of Compound Represented by Formula (I-2)

50 parts of the compound represented by the formula (I-2-a), 8.97 parts of the salt represented by the formula (I-2-c) and 500 parts of chloroform are mixed and stirred at 23° C. for 30 minutes, 38.60 parts of the compound represented by the formula (I-2-b) was added and further stirred at 23°C for 18 hours. After adding 200 parts of ion-exchanged water to the obtained reaction mass and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. After adding 300 parts of a 10% potassium carbonate aqueous solution to the recovered organic layer and stirring at 23° C. for 30 minutes, the organic layer was taken out by liquid separation. After adding 150 parts of ion-exchanged water to the recovered organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated four times. By concentrating the obtained organic layer, 43.65 parts of the compound represented by the formula (I-2-d) was obtained.

75.92 parts of the compound represented by the formula (I-2-e) and 23.85 parts of the compound represented by the formula (I-2-f) were mixed, stirred at 23°C for 30 minutes, and then heated to 0°C. cooled to After adding 500 parts of tetrahydrofuran to the obtained mixed solution, the mixture was stirred for 30 minutes and heated to 23°C. To the resulting mixture, 37.50 parts of the compound represented by formula (I-2-d) was added and stirred at 23°C for 12 hours. After concentrating the obtained reaction mass, 550 parts of ethyl acetate and 250 parts of ion-exchanged water were added to the obtained concentrated residue, and the mixture was stirred at 23° C. for 30 minutes. This washing operation was repeated three times. The obtained organic layer is concentrated, and the concentrated mass is collected by column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=1/1). Thus, 15.28 parts of the compound represented by formula (I-2) was obtained.
MASS: 211.1 [M+H] ⁺

式（Ｉ－１５－ａ）で表される化合物５０部、式（Ｉ－２－ｃ）で表される塩８．９７部及びクロロホルム５００部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－２－ｂ）で表される化合物３８．６０部を添加し、さらに、２３℃で１８時間攪拌した。得られた反応マスに、イオン交換水２００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層に１０％炭酸カリウム水溶液３００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を４回繰り返した。得られた有機層を濃縮することにより、式（Ｉ－１５－ｄ）で表される化合物３９．２１部を得た。

式（Ｉ－２－ｅ）で表される化合物７５．９２部及び式（Ｉ－２－ｆ）で表される化合物２３．８５部を混合し、２３℃で３０分間攪拌した後、０℃まで冷却した。得られた混合溶液に、テトラヒドロフラン５００部を添加した後、３０分間攪拌し、２３℃まで昇温した。得られた混合物に、式（Ｉ－２－ｄ）で表される化合物３７．５０部を添加し、２３℃で１２時間攪拌した。得られた反応マスを濃縮した後、得られた濃縮残に、酢酸エチル５５０部及びイオン交換水２５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮し、濃縮マスをカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝１／１）分取することにより、式（Ｉ－１５）で表される化合物１１．１８部を得た。
ＭＡＳＳ：２１１．１（分子イオンピーク） ［Ｍ＋Ｈ］^＋ Synthesis Example 2: Synthesis of Compound Represented by Formula (I-15)

50 parts of the compound represented by the formula (I-15-a), 8.97 parts of the salt represented by the formula (I-2-c) and 500 parts of chloroform are mixed and stirred at 23° C. for 30 minutes, 38.60 parts of the compound represented by the formula (I-2-b) was added and further stirred at 23°C for 18 hours. After adding 200 parts of ion-exchanged water to the obtained reaction mass and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. After adding 300 parts of a 10% potassium carbonate aqueous solution to the recovered organic layer and stirring at 23° C. for 30 minutes, the organic layer was taken out by liquid separation. After adding 150 parts of ion-exchanged water to the recovered organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated four times. By concentrating the obtained organic layer, 39.21 parts of the compound represented by the formula (I-15-d) was obtained.

75.92 parts of the compound represented by the formula (I-2-e) and 23.85 parts of the compound represented by the formula (I-2-f) were mixed, stirred at 23°C for 30 minutes, and then heated to 0°C. cooled to After adding 500 parts of tetrahydrofuran to the obtained mixed solution, the mixture was stirred for 30 minutes and heated to 23°C. To the resulting mixture, 37.50 parts of the compound represented by formula (I-2-d) was added and stirred at 23°C for 12 hours. After concentrating the obtained reaction mass, 550 parts of ethyl acetate and 250 parts of ion-exchanged water were added to the obtained concentrated residue, and the mixture was stirred at 23° C. for 30 minutes. This washing operation was repeated three times. The obtained organic layer is concentrated, and the concentrated mass is collected by column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=1/1). Thus, 11.18 parts of the compound represented by formula (I-15) was obtained.
MASS: 211.1 (molecular ion peak) [M+H] ⁺

式（Ｉ－４－ａ）で表される化合物５０部、式（Ｉ－２－ｃ）で表される塩７．９５部及びクロロホルム５００部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－２－ｂ）で表される化合物３４．２２部を添加し、さらに、２３℃で１８時間攪拌した。得られた反応マスに、イオン交換水２００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層に１０％炭酸カリウム水溶液３００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を４回繰り返した。得られた有機層を濃縮することにより、式（Ｉ－４－ｄ）で表される化合物３８．２９部を得た。

式（Ｉ－２－ｅ）で表される化合物３７．９６部及び式（Ｉ－２－ｆ）で表される化合物１１．９３部を混合し、２３℃で３０分間攪拌した後、０℃まで冷却した。得られた混合溶液に、テトラヒドロフラン３００部を添加した後、３０分間攪拌し、２３℃まで昇温した。得られた混合物に、式（Ｉ－４－ｄ）で表される化合物２０．３４部を添加し、２３℃で１２時間攪拌した。得られた反応マスを濃縮した後、得られた濃縮残に、酢酸エチル５００部及びイオン交換水２００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮し、濃縮マスをカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝１／１）分取することにより、式（Ｉ－４）で表される化合物１０．１９部を得た。
ＭＡＳＳ：２２９．１ ［Ｍ＋Ｈ］^＋ Synthesis Example 3: Synthesis of Compound Represented by Formula (I-4)

50 parts of the compound represented by the formula (I-4-a), 7.95 parts of the salt represented by the formula (I-2-c) and 500 parts of chloroform were mixed and stirred at 23°C for 30 minutes, 34.22 parts of the compound represented by the formula (I-2-b) was added and further stirred at 23° C. for 18 hours. After adding 200 parts of ion-exchanged water to the obtained reaction mass and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. After adding 300 parts of a 10% potassium carbonate aqueous solution to the recovered organic layer and stirring at 23° C. for 30 minutes, the organic layer was taken out by liquid separation. After adding 150 parts of ion-exchanged water to the recovered organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated four times. By concentrating the obtained organic layer, 38.29 parts of the compound represented by the formula (I-4-d) was obtained.

37.96 parts of the compound represented by the formula (I-2-e) and 11.93 parts of the compound represented by the formula (I-2-f) were mixed, stirred at 23°C for 30 minutes, and then heated to 0°C. cooled to After adding 300 parts of tetrahydrofuran to the obtained mixed solution, the mixture was stirred for 30 minutes and heated to 23°C. To the resulting mixture, 20.34 parts of the compound represented by formula (I-4-d) was added and stirred at 23°C for 12 hours. After concentrating the obtained reaction mass, 500 parts of ethyl acetate and 200 parts of ion-exchanged water were added to the obtained concentration residue, and the mixture was stirred at 23° C. for 30 minutes. This washing operation was repeated three times. The obtained organic layer is concentrated, and the concentrated mass is collected by column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=1/1). Thus, 10.19 parts of the compound represented by formula (I-4) was obtained.
MASS: 229.1 [M+H] ⁺

式（Ｉ－５－ａ）で表される化合物５０部、式（Ｉ－２－ｃ）で表される塩７．９５部及びクロロホルム５００部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－２－ｂ）で表される化合物３４．２２部を添加し、さらに、２３℃で１８時間攪拌した。得られた反応マスに、イオン交換水２００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層に１０％炭酸カリウム水溶液３００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を４回繰り返した。得られた有機層を濃縮することにより、式（Ｉ－５－ｄ）で表される化合物３２．２２部を得た。

式（Ｉ－２－ｅ）で表される化合物３７．９６部及び式（Ｉ－２－ｆ）で表される化合物１１．９３部を混合し、２３℃で３０分間攪拌した後、０℃まで冷却した。得られた混合溶液に、テトラヒドロフラン３００部を添加した後、３０分間攪拌し、２３℃まで昇温した。得られた混合物に、式（Ｉ－５－ｄ）で表される化合物２０．３４部を添加し、２３℃で１２時間攪拌した。得られた反応マスを濃縮した後、得られた濃縮残に、酢酸エチル５００部及びイオン交換水２００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮し、濃縮マスをカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝１／１）分取することにより、式（Ｉ－５）で表される化合物８．７９部を得た。
ＭＡＳＳ：２２９．１ ［Ｍ＋Ｈ］^＋ Synthesis Example 4: Synthesis of Compound Represented by Formula (I-5)

50 parts of the compound represented by the formula (I-5-a), 7.95 parts of the salt represented by the formula (I-2-c) and 500 parts of chloroform are mixed and stirred at 23° C. for 30 minutes, 34.22 parts of the compound represented by the formula (I-2-b) was added and further stirred at 23° C. for 18 hours. After adding 200 parts of ion-exchanged water to the obtained reaction mass and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. After adding 300 parts of a 10% potassium carbonate aqueous solution to the recovered organic layer and stirring at 23° C. for 30 minutes, the organic layer was taken out by liquid separation. After adding 150 parts of ion-exchanged water to the recovered organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated four times. By concentrating the obtained organic layer, 32.22 parts of the compound represented by the formula (I-5-d) was obtained.

37.96 parts of the compound represented by the formula (I-2-e) and 11.93 parts of the compound represented by the formula (I-2-f) were mixed, stirred at 23°C for 30 minutes, and then heated to 0°C. cooled to After adding 300 parts of tetrahydrofuran to the obtained mixed solution, the mixture was stirred for 30 minutes and heated to 23°C. To the resulting mixture, 20.34 parts of the compound represented by formula (I-5-d) was added and stirred at 23°C for 12 hours. After concentrating the obtained reaction mass, 500 parts of ethyl acetate and 200 parts of ion-exchanged water were added to the obtained concentration residue, and the mixture was stirred at 23° C. for 30 minutes. This washing operation was repeated three times. The obtained organic layer is concentrated, and the concentrated mass is collected by column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=1/1). Thus, 8.79 parts of the compound represented by formula (I-5) was obtained.
MASS: 229.1 [M+H] ⁺

Synthesis of Resin The compounds (monomers) used in synthesizing the resin are shown below.

Hereinafter, these monomers are referred to as "monomer (a1-1-3)" and the like according to their formula numbers.

Example 1 [Synthesis of Resin A1]
As monomers, monomer (I-2), monomer (a1-1-3), monomer (a1-2-6), monomer (a3-1-1) and monomer (II-2-A-1-1) used, the molar ratio [monomer (I-2): monomer (a1-1-3): monomer (a1-2-6): monomer (a3-1-1): monomer (II-2-A-1- 1)] are mixed at a ratio of 35:24:35:3:3, and further, methyl isobutyl ketone is mixed in an amount of 1.5 times the mass of the total mass of all monomers to this monomer mixture. did. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 83° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin A1 (copolymer) having a weight average molecular weight of about 5.1×10 ³ with a yield of 72. obtained in %. This resin A1 has the following structural units.

Example 2 [Synthesis of resin A2]
As monomers, monomer (I-2), monomer (a1-1-3), monomer (a1-2-6) and monomer (a3-1-1) are used, and the molar ratio [monomer (I-2): Monomer (a1-1-3) : Monomer (a1-2-6) : Monomer (a3-1-1)] is mixed so that the ratio is 38:24:35:3, and this monomer mixture 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin A2 (copolymer) having a weight average molecular weight of about 5.0×10 ³ with a yield of 80%. obtained in %. This resin A2 has the following structural units.

Example 3 [Synthesis of Resin A3]
Monomer (I-2), monomer (a1-1-3) and monomer (a1-2-6) are used as monomers, and the molar ratio [monomer (I-2):monomer (a1-1-3): Monomer (a1-2-6)] are mixed in a ratio of 38:24:38, and methyl isobutyl ketone is added to the monomer mixture in an amount 1.5 times the mass of the total mass of all the monomers. were mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin A3 (copolymer) having a weight average molecular weight of about 4.8×10 ³ with a yield of 70%. obtained in %. This resin A3 has the following structural units.

Example 4 [Synthesis of resin A4]
As monomers, monomer (I-15), monomer (a1-1-3), monomer (a1-2-6) and monomer (a3-1-1) are used, and the molar ratio [monomer (I-15): Monomer (a1-1-3) : Monomer (a1-2-6) : Monomer (a3-1-1)] is mixed so that the ratio is 38:24:35:3, and this monomer mixture 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin A4 (copolymer) having a weight average molecular weight of about 4.8×10 ³ with a yield of 74. obtained in %. This resin A4 has the following structural units.

Example 5 [Synthesis of Resin A5]
As monomers, monomer (I-15), monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-1) and monomer (a3-1-1) are used, and the mol The ratio [monomer (I-15):monomer (a1-1-3):monomer (a1-2-6):monomer (a2-1-1):monomer (a3-1-1)] is 38:24 :30:5:3, and this monomer mixture was further mixed with methyl isobutyl ketone in an amount of 1.5 times the mass of the total mass of all the monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin A5 (copolymer) having a weight average molecular weight of about 4.9×10 ³ with a yield of 68. obtained in %. This resin A5 has the following structural units.

Example 6 [Synthesis of Resin A6]
As monomers, monomer (a1-4-2), monomer (I-2), monomer (a1-1-3), monomer (a1-2-6) and monomer (a3-1-1) are used, and the mol The ratio [monomer (a1-4-2):monomer (I-2):monomer (a1-1-3):monomer (a1-2-6):monomer (a3-1-1)] is 20:18 :24:35:3, and this monomer mixture was further mixed with 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all the monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin A6 (copolymer) having a weight average molecular weight of about 4.9×10 ³ with a yield of 83. obtained in %. This resin A6 has the following structural units.

Example 7 [Synthesis of Resin A7]
As monomers, monomer (I-2), monomer (a1-1-3), monomer (a1-2-6) and monomer (a3-1-1) are used, and the molar ratio [monomer (I-2): Monomer (a1-1-3) : Monomer (a1-2-6) : Monomer (a3-1-1)] is mixed so that the ratio is 38:24:35:3, and this monomer mixture 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, after cooling the polymerization reaction solution to 15° C., an aqueous solution of p-toluenesulfonic acid was added, and the solution was separated after stirring for 6 hours. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin A7 (copolymer) having a weight average molecular weight of about 5.0×10 ³ with a yield of 80%. obtained in %. This resin A7 has the following structural units (acid-labile group (ethoxyethyl group) elimination rate of structural unit (I-2) is 60%).

Example 8 [Synthesis of Resin A8]
As monomers, monomer (I-2), monomer (a1-1-3), monomer (a1-2-6) and monomer (a3-1-1) are used, and the molar ratio [monomer (I-2): Monomer (a1-1-3) : Monomer (a1-2-6) : Monomer (a3-1-1)] is mixed so that the ratio is 38:24:35:3, and this monomer mixture 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. After that, the polymerization reaction solution was cooled to 15° C., poured into a large amount of n-heptane to precipitate the resin, and filtered and collected to obtain resin A8 (copolymerization) having a weight average molecular weight of about 5.4×10 ³ . ) was obtained in 82% yield. This resin A8 has the following structural units.

Example 9 [Synthesis of Resin A9]
Monomer (I-4), monomer (a1-1-3) and monomer (a1-2-6) are used as monomers, and the molar ratio [monomer (I-4):monomer (a1-1-3): Monomer (a1-2-6)] are mixed in a ratio of 38:24:38, and methyl isobutyl ketone is added to the monomer mixture in an amount 1.5 times the mass of the total mass of all the monomers. were mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin A9 (copolymer) having a weight average molecular weight of about 5.2×10 ³ with a yield of 65%. obtained in %. This resin A9 has the following structural units.

Example 10 [Synthesis of resin A10]
As monomers, monomer (I-5), monomer (a1-1-3) and monomer (a1-2-6) are used, and the molar ratio [monomer (I-5):monomer (a1-1-3): Monomer (a1-2-6)] are mixed in a ratio of 38:24:38, and methyl isobutyl ketone is added to the monomer mixture in an amount 1.5 times the mass of the total mass of all the monomers. were mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A10 (copolymer) having a weight average molecular weight of about 5.5×10 ³ with a yield of 61. obtained in %. This resin A10 has the following structural units.

Example 11 [Synthesis of Resin A11]
As monomers, monomer (a1-4-2), monomer (I-4), monomer (a1-1-3), monomer (a1-2-6) and monomer (a3-1-1) are used, and the mol The ratio [monomer (a1-4-2):monomer (I-4):monomer (a1-1-3):monomer (a1-2-6):monomer (a3-1-1)] is 20:18 :24:35:3, and this monomer mixture was further mixed with 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all the monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A11 (copolymer) having a weight average molecular weight of about 5.1×10 ³ with a yield of 77%. obtained in %. This resin A11 has the following structural units.

Example 12 [Synthesis of Resin A12]
As monomers, monomer (a1-4-2), monomer (I-5), monomer (a1-1-3), monomer (a1-2-6) and monomer (a3-1-1) are used, and the mol The ratio [monomer (a1-4-2):monomer (I-5):monomer (a1-1-3):monomer (a1-2-6):monomer (a3-1-1)] is 20:18 :24:35:3, and this monomer mixture was further mixed with 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all the monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A12 (copolymer) having a weight average molecular weight of about 5.2×10 ³ with a yield of 73. obtained in %. This resin A12 has the following structural units.

Synthesis Example 5 [Synthesis of Resin AX1]
As monomers, monomer (I-2), monomer (a1-1-3) and monomer (a3-1-1) are used, and the molar ratio [monomer (I-2): monomer (a1-1-3): Monomer (a3-1-1)] were mixed in a ratio of 38:59:3, and methyl isobutyl ketone was added to the monomer mixture in an amount 1.5 times the mass of the total mass of all the monomers. were mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin AX1 (copolymer) having a weight average molecular weight of about 5.1×10 ³ with a yield of 77%. obtained in %. This resin AX1 has the following structural units.

Synthesis Example 6 [Synthesis of Resin AX2]
As monomers, monomer (I-2), monomer (a1-2-6) and monomer (a3-1-1) are used, and the molar ratio [monomer (I-2): monomer (a1-2-6): Monomer (a3-1-1)] were mixed in a ratio of 38:59:3, and methyl isobutyl ketone was added to the monomer mixture in an amount 1.5 times the mass of the total mass of all the monomers. were mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin AX2 (copolymer) having a weight average molecular weight of about 5.6×10 ³ with a yield of 85%. obtained in %. This resin AX2 has the following structural units.

Synthesis Example 7 [Synthesis of Resin AX3]
As monomers, monomer (I-15), monomer (a1-1-2), monomer (a2-1-1) and monomer (a3-1-1) are used, and the molar ratio [monomer (I-15): Monomer (a1-1-2) : Monomer (a2-1-1) : Monomer (a3-1-1)] is mixed so that the ratio is 10:30:25:35, and this monomer mixture 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to carry out polymerization. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain a resin AX3 (copolymer) having a weight average molecular weight of about 5.8×10 ³ with a yield of 87%. obtained in %. This resin AX3 has the following structural units.

<Preparation of resist composition>
A mixture obtained by mixing and dissolving each component shown in Table 1 was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

＜クエンチャー（Ｃ）＞
Ｃ１：特開２０１１－３９５０２号公報記載の方法で合成

＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ４００部
プロピレングリコールモノメチルエーテル １５０部
γ－ブチロラクトン ５部 <Resin>
A1-A12, AX1-AX3: Resin A1-Resin A8, Resin AX1-Resin AX3
<Acid generator (B)>
B1-43: a salt represented by the formula (B1-43) (synthesized according to the examples of JP-A-2016-47815)

<Quencher (C)>
C1: synthesized by the method described in JP-A-2011-39502

<Solvent>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 150 parts γ-butyrolactone 5 parts

(Evaluation of resist composition by electron beam exposure)
A 6-inch silicon wafer was treated with hexamethyldisilazane at 90° C. for 60 seconds on a direct hotplate. This silicon wafer was spin-coated with the resist composition so that the film thickness of the composition layer was 0.04 μm. After that, it was pre-baked for 60 seconds on a direct hot plate at the temperature shown in the "PB" column of Table 1 to form a composition layer. A line-and-space pattern was directly drawn on the composition layer formed on the wafer using an electron beam lithography machine ["HL-800D 50 keV" manufactured by Hitachi, Ltd.] while changing the exposure dose stepwise. .
After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 1 for 60 seconds, and puddle development was performed for 60 seconds with a 2.38% by mass tetramethylammonium hydroxide aqueous solution. , a resist pattern was obtained.
The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the effective sensitivity was defined as the exposure dose at which the line width and space width of the 60 nm line and space pattern were 1:1.

Line Edge Roughness Evaluation (LER): Line edge roughness was obtained by measuring the unevenness amplitude of the side wall surface of the resist pattern manufactured at effective sensitivity with a scanning electron microscope. Table 2 shows the results.

INDUSTRIAL APPLICABILITY A resist composition containing the resin of the present invention is suitable for microfabrication of semiconductors and extremely useful industrially because the resulting resist pattern has excellent line edge roughness (LER).

Claims (7)

A resin comprising a structural unit represented by formula (I), a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2).

[in the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
X ¹ represents a single bond or -CO-O-* (* represents a bonding position with Ar).
Ar represents a divalent aromatic hydrocarbon group having 6 to 36 carbon atoms and having a fluorine atom.
R ² represents an acid labile group represented by formula (1a) or formula (2a) . ]

[In the formulas (a1-1) and (a1-2),
L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, k1 represents an integer of 1 to 7, * represents -CO- represents a bond with
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents any integer from 0 to 14;
n1 represents any integer from 0 to 10;
n1' represents an integer of 0 to 3; ]

[In the formula (1a), R ^aa1 , R ^aa2 and R ^aa3 are each independently an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon represents an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^aa1 and R ^aa2 are bonded together to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
naa represents 0 or 1;
* represents a bond. ]

[In formula (2a), R ^{aa1 '} and R ^{aa2 '} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{aa3 '} represents a hydrocarbon group having 1 to 20 carbon atoms. or R ^aa2′ and R ^aa3′ are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with —C—X ^a — to which they are bonded, and the hydrocarbon group and the heterocyclic group -CH ₂ - included may be replaced with -O- or -S-.
X ^a represents an oxygen atom or a sulfur atom.
* represents a bond. ] 2. The resin according to claim 1 , wherein Ar is a phenylene group having a fluorine atom. 3. The resin according to claim ¹ or 2 , wherein X1 is a single bond. A resist composition comprising the resin according to any one of claims 1 to 3 and an acid generator. 5. The resist composition according to claim 4 , wherein the acid generator is a salt represented by formula (B1).

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO— , a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S(O) ₂ - or -CO-.
Z ⁺ represents an organic cation. ] 6. The resist composition according to claim 4 , further comprising a salt that generates an acid weaker in acidity than the acid generated from the acid generator. (1) a step of applying the resist composition according to any one of claims 4 to 6 onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) heating the composition layer after exposure; and (5) developing the composition layer after heating;
A method of manufacturing a resist pattern comprising: