JP2023112680A - Resist composition and method for producing resist pattern - Google Patents

Abstract

To provide a resist composition from which a resist pattern having few defects and good CD uniformity (CDU) can be produced.SOLUTION: The resist composition contains: (A1) a resin containing a structural unit represented by formula (I) and a structural unit represented by formula (III); (A2) a resin having an acid-labile group; and an acid generator. [X1 represents *-CO-O-; L1 represents an optionally substituted chain hydrocarbon group; R2 represents a fluorinated alkyl group; R3 represents a hydrogen atom or a fluorinated alkyl group; X2 represents a single bond or *-CO-O-; and mi and mk each represent an integer of 1-4.]SELECTED DRAWING: None

Description

The present invention relates to a resist composition and a method for producing a resist pattern using the resist composition.

Patent Document 1 also describes a resist composition containing a resin containing the following structural unit, a resin having an acid-labile group, and an acid generator.

JP 2009-191151 A

An object of the present invention is to provide a resist composition that forms a resist pattern with fewer defects and better CD uniformity (CDU) than the resist pattern formed from the above resist composition.

［式（Ｉ）中、
Ｒ^１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。
Ｘ^１は、＊－ＣＯ－Ｏ－を表す。＊は、Ｒ^１が結合する炭素原子との結合部位を表す。
Ｌ^１は、置換基を有していてもよい炭素数１～２８の鎖状の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｒ^２は、炭素数１～８のフッ化アルキル基を表す。
Ｒ^３は、水素原子又は炭素数１～６のフッ化アルキル基を表す。
ｍｉは、１～４のいずれかの整数を表す。］

［式（ＩＩＩ）中、
Ｒ^４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。
Ｘ^２は、単結合又は＊－ＣＯ－Ｏ－を表す。＊は、Ｒ^４が結合する炭素原子との結合部位を表す。
Ｌ^２は、単結合又は置換基を有していてもよい炭素数１～２８の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
ｍｋは、１～４のいずれかの整数を表す。］
［２］Ｌ^１が、置換基を有していてもよい炭素数１～１２の鎖式炭化水素基である［１］に記載のレジスト組成物。
［３］式（Ｉ）で表される構造単位が、式（Ｉ－１）で表される構造単位である［１］又は［２］に記載のレジスト組成物。

［式（Ｉ－１）中、
Ｒ^１、Ｘ^１、Ｒ^２、Ｒ^３は、式（Ｉ）と同じものを表す。
Ｌ^１０は、単結合又は炭素数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－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わってもよい。ｍｉ１が２以上の場合、複数のＬ^１０は、互いに同じであっても異なっていてもよい。
Ｒ^１０は、水素原子、炭素数１～１２のアルキル基、炭素数３～１８の脂環式炭化水素基（該脂環式炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。該脂環式炭化水素基は、置換基を有していてもよい。）又は炭素数６～１８の芳香族炭化水素基（該芳香族炭化水素基は、置換基を有してもよい。）を表す。ｍｉ２が２以上の場合、複数のＲ^１０は、互いに同じであっても異なっていてもよい。
ｍｉ１は、１～３のいずれかの整数を表す。
ｍｉ２は、３－ｍｉ１を満たす整数を表す。］
［４］Ｌ^２が、炭素数１～９の鎖式炭化水素基（該鎖式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。）、炭素数３～１２の脂環式炭化水素基（該脂環式炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－に置き換わっていてもよい。）又は炭素数６～１０の芳香族炭化水素基（該芳香族炭化水素基は、１以上のハロゲン原子、１以上の炭素数１～３のアルキル基、１以上の炭素数１～３のハロアルキル基又は１以上の炭素数１～３のアルコキシ基を有してもよい。）である［１］～［３］のいずれかに記載のレジスト組成物。
［５］（Ａ２）酸不安定基を有する樹脂が、式（ａ１－０）で表される構造単位、式（ａ１－１）で表される構造単位及び式（ａ１－２）で表される構造単位からなる群より選ばれる少なくとも１種を含む［１］～［４］のいずれかに記載のレジスト組成物。

［式（ａ１－０）、式（ａ１－１）及び式（ａ１－２）中、
Ｌ^a01、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－との結合部位を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、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^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、炭素数６～１８の芳香族炭化水素基又はこれらを組み合わせた基を表す。
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２～８のアルケニル基、炭素数３～１８の脂環式炭化水素基、炭素数６～１８の芳香族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。］
［６］（Ａ２）酸不安定基を有する樹脂が、式（ａ２－Ａ）で表される構造単位を含む［１］～［５］のいずれかに記載のレジスト組成物。

［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いてもよい炭素数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２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、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部位を表す。
Ａ^a52は、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いてもよい。］
［７］酸発生剤が、式（Ｂ１）で表される塩を含む［１］～［６］のいずれかに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、水素原子、フッ素原子、炭素数１～６のアルキル基又は炭素数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３～２４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－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ１^＋は、有機カチオンを表す。］
［８］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［１］～［７］のいずれかに記載のレジスト組成物。
［９］（１）［１］～［８］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] (A1) a resin containing a structural unit represented by formula (I) and a structural unit represented by formula (III);
(A2) a resin having an acid-labile group, and
A resist composition containing an acid generator.

[in the formula (I),
R ¹ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
X ¹ represents *-CO-O-. * represents the binding site to the carbon atom to which ^R1 binds.
L ¹ represents an optionally substituted chain hydrocarbon group having 1 to 28 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —S—, — SO ₂ - or -CO- may be substituted.
R ² represents a fluorinated alkyl group having 1 to 8 carbon atoms.
R ³ represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
mi represents an integer of 1 to 4; ]

[in the formula (III),
R ⁴ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
^X2 represents a single bond or *-CO-O-. * represents the binding site to the carbon atom to which ^R4 binds.
L ² represents a single bond or an optionally substituted hydrocarbon group having 1 to 28 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —S—, — SO ₂ - or -CO- may be substituted.
mk represents an integer of 1-4. ]
[2] The resist composition according to [ ¹ ], wherein L 1 is an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms.
[3] The resist composition according to [1] or [2], wherein the structural unit represented by formula (I) is a structural unit represented by formula (I-1).

[In the formula (I-1),
R ¹ , X ¹ , R ² and R ³ represent the same as in formula (I).
L ¹⁰ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and —CH ₂ — contained in the alkanediyl group may be replaced with —O— or —CO—. When mi1 is 2 or more, a plurality of ^L10 may be the same or different.
R ¹⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms (-CH ₂ - contained in the alicyclic hydrocarbon group is -O- or - may be substituted with CO—.The alicyclic hydrocarbon group may have a substituent.) or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group is may have a substituent). When mi2 is 2 or more, multiple R ¹⁰ may be the same or different.
mi1 represents an integer of 1 to 3;
mi2 represents an integer that satisfies 3-mi1. ]
[4] L ² is a chain hydrocarbon group having 1 to 9 carbon atoms (-CH ₂ - contained in the chain hydrocarbon group may be replaced with -O- or -CO-); an alicyclic hydrocarbon group having 3 to 12 carbon atoms (-CH ₂ - contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO ₂ -; ) or an aromatic hydrocarbon group having 6 to 10 carbon atoms (the aromatic hydrocarbon group is one or more halogen atoms, one or more alkyl groups having 1 to 3 carbon atoms, one or more carbon atoms of 1 to 3 or one or more alkoxy groups having 1 to 3 carbon atoms).
[5] (A2) The resin having an acid-labile group comprises a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1) and a resin represented by formula (a1-2). The resist composition according to any one of [1] to [4], containing at least one selected from the group consisting of structural units.

[In formula (a1-0), formula (a1-1) and formula (a1-2),
L ^a01 , L ^a1 and L ^a2 each independently represent —O— or *—O—(CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, * is represents the binding site with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom, a halogen atom or an optionally halogenated alkyl group having 1 to 6 carbon atoms.
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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or represents a combined group.
R ^a6 and R ^a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. It represents a hydrocarbon group or a group formed by combining these groups.
m1 represents any integer from 0 to 14;
n1 represents any integer from 0 to 10;
n1' represents an integer of 0 to 3; ]
[6] The resist composition according to any one of [1] to [5], wherein (A2) the resin having an acid-labile group contains a structural unit represented by formula (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 alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, It represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51 -(A ^a52 -X ^a52 ) _nb -, and * represents a bonding site with the carbon atom to which -R ^a50 bonds.
A ^a52 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. ]
[7] The resist composition according to any one of [1] to [6], wherein the acid generator contains a salt represented by formula (B1).

[In formula (B1),
Q ^b1 and Q ^b2 each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms or a perfluoroalkyl group having 1 to 6 carbon atoms.
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 24 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S-, -SO ₂ - or -CO-.
Z1 ⁺ represents an organic cation. ]
[8] The resist composition according to any one of [1] to [7], further comprising a salt that generates an acid weaker in acidity than the acid generated by the acid generator.
[9] (1) a step of applying the resist composition according to any one of [1] to [8] 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:

By using the resist composition of the present invention, a resist pattern can be produced with few defects and good CD uniformity (CDU).

As used herein, "(meth)acrylic monomer" means "at least one of acrylic monomer and methacrylic monomer". Notations such as "(meth)acrylate" and "(meth)acrylic acid" have the same meaning. In addition, among the groups described in this specification, any group that can have both a linear structure and a branched structure may be used. When —CH ₂ — contained in a hydrocarbon group or the like is replaced with —O—, —S—, —CO— or —SO ₂ —, the same examples apply to each group. A "combined group" means a group in which two or more of the exemplified groups are bonded, and the valence of these groups may be changed as appropriate depending on the bonding form. "Derived from" or "derived from" refers to the polymerization of a polymerizable C=C bond contained in the molecule to a -C-C- group (single bond). Where 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.

<Resist composition>
The resist composition of the present invention is
a resin component (hereinafter sometimes referred to as "resin component (A)") and
It contains an acid generator (hereinafter sometimes referred to as "acid generator (B)").
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)").

<Resin component (A)>
The resin component (A) contains two or more resins, and at least (A1) a resin containing a structural unit represented by formula (I) and a structural unit represented by formula (III) (hereinafter “resin (A1)” sometimes called), and
(A2) Contains a resin having an acid-labile group (hereinafter sometimes referred to as "resin (A2)").
As used herein, the term "acid-labile group" refers to a group that has a leaving group, and upon contact with an acid, the leaving group leaves to form a hydrophilic group (e.g., hydroxy group or carboxy group). means
Moreover, the resin component (A) may contain a resin other than the resins (A1) and (A2), which will be described later.

［式（Ｉ）中、
Ｒ^１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。
Ｘ^１は、＊－ＣＯ－Ｏ－を表す。＊は、Ｒ^１が結合する炭素原子との結合部位を表す。
Ｌ^１は、置換基を有していてもよい炭素数１～２８の鎖状の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｒ^２は、炭素数１～８のフッ化アルキル基を表す。
Ｒ^３は、水素原子又は炭素数１～６のフッ化アルキル基を表す。
ｍｉは、１～４のいずれかの整数を表す。］ <Resin (A1)>
Resin (A1) contains a structural unit represented by formula (I) (hereinafter sometimes referred to as “structural unit (I)”).

[in the formula (I),
R ¹ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
X ¹ represents *-CO-O-. * represents the binding site to the carbon atom to which ^R1 binds.
L ¹ represents an optionally substituted chain hydrocarbon group having 1 to 28 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —S—, — SO ₂ - or -CO- may be substituted.
R ² represents a fluorinated alkyl group having 1 to 8 carbon atoms.
R ³ represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
mi represents an integer of 1 to 4; ]

The alkyl group having 1 to 6 carbon atoms in R ¹ includes methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group. .
A halogen atom for R ¹ includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.
The alkyl group having 1 to 6 carbon atoms and having a halogen atom for R ¹ includes trifluoromethyl group, difluoromethyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2- Tetrafluoroethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluoro pentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, perfluorohexyl group, trichloromethyl group, dichloromethyl group, triiodomethyl group, diiodomethyl group, tribromomethyl group , a dibromomethyl group, and the like.
R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, a hydrogen atom or a methyl group is even more preferred.

The chain hydrocarbon group for L ¹ includes divalent to pentavalent chain hydrocarbon groups such as an alkanediyl group, an alkanetriyl group, an alkanetetrayl group and an alkanepentyl group.
The alkanediyl groups include methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, 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 linear groups such as tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl and heptadecane-1,17-diyl alkanediyl group and 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, Branched alkanediyl groups such as 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2-methylbutane-1,4-diyl group are mentioned.
Alkanetriyl groups include methanetriyl, ethanetriyl, propanetriyl, butanetriyl, pentanetriyl, hexanetriyl, heptanetriyl, octanetriyl, nonanetriyl, decanetriyl, and undecanetriyl groups. , dodecanetriyl group, tridecanetriyl group, tetradecanetriyl group, pentadecanetriyl group, hexadecanetriyl group and heptadecanetriyl group.
The alkanetetrayl group includes a methantetrayl group, an ethanetetrayl group, a propanetetrayl group, a butanetetrayl group, a pentanetetrayl group, a hexanetetrayl group, a heptanetetrayl group, an octanetetrayl group, and a nonanetetrayl group. group, decanetetrayl group, undecanetetrayl group, dodecanetetrayl group, tridecanetetrayl group, tetradecanetetrayl group, pentadecanetetrayl group, hexadecanetetrayl group and heptadecanetetrayl group.
Also included are groups in which one or more hydrogen atoms of the above groups are replaced with bonding sites.
The chain hydrocarbon group preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 10 carbon atoms, still more preferably 1 to 9 carbon atoms, and still more preferably 1 to 8, even more preferably 1 to 6, even more preferably 1 to 5, and particularly preferably 1 to 4.

When —CH ₂ — contained in the chain hydrocarbon group in L ¹ is replaced with —O—, —S—, —SO ₂ — or —CO—, the number of carbon atoms before the replacement is is the total carbon number of Examples of substituted groups include a hydroxy group (a group in which —CH ₂ — contained in a methyl group is replaced by —O—), a thiol group (a group in which —CH ₂ — contained in a methyl group is replaced by —S—). group), carboxy group (group in which —CH ₂ —CH ₂ — contained in an ethyl group is replaced with —O—CO-), alkoxy group (any position of —CH ₂ — in an alkyl group is replaced with —O—), alkylthio group (group in which —CH ₂ — at any position in the alkyl group is replaced with —S—), alkoxycarbonyl group (any -CH ₂ -CH ₂ - at the position is replaced with -O-CO-), alkylcarbonyl group (group in which -CH ₂ - at any position in the alkyl group is replaced with -CO- ), alkylsulfonyl group (a group in which —CH ₂ — at any position in the alkyl group is replaced with —SO ₂ —), alkylcarbonyloxy group ( —CH ₂ at any position in the alkyl group) —CH ₂ — is replaced by —CO—O—), oxy group (group in which —CH ₂ — contained in the methylene group is replaced by —O-), carbonyl group (contained in the methylene group -CH ₂ - is replaced by -CO-), thio group (group in which -CH ₂ - contained in the methylene group is replaced by -S-), sulfonyl group (-CH 2 - contained in the methylene group _2- is replaced with -SO ₂ -), alkanediyloxy group (group in which any position of -CH ₂ - contained in the alkanediyl group is replaced with -O-), alkanediyloxycarbonyl group (A group in which —CH ₂ —CH ₂ — at any position in the alkanediyl group is replaced with —O—CO—), alkanediylcarbonyl group (—CH at any position in the alkanediyl group _2- is a group substituted with -CO-), an alkanediylcarbonyloxy group (an arbitrary position of the alkanediyl group -CH ₂ -CH ₂ - is substituted with -CO-O-), Alkanediylsulfonyl group (a group in which —CH ₂ — at any position in the alkanediyl group is replaced with —SO ₂ —), alkanediylthio group ( —CH at any position in the alkanediyl group) _2- is a group in which -S- is substituted), groups in which two or more of these groups are combined, and the like.
The alkoxy group includes alkoxy groups having 1 to 27 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy. group, decyloxy group, undecyloxy group, and the like. The alkoxy group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The alkylthio group includes alkylthio groups having 1 to 27 carbon atoms, such as methylthio, ethylthio, propylthio and butylthio groups. The number of carbon atoms in the alkylthio group is preferably 1-11, more preferably 1-6, even more preferably 1-4, still more preferably 1-3.
The alkoxycarbonyl group includes an alkoxycarbonyl group having 2 to 27 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, and the like. The alkylcarbonyl group includes an alkyl group having 2 to 28 carbon atoms. Carbonyl groups include, for example, acetyl, propionyl and butyryl groups, and alkylcarbonyloxy groups include alkylcarbonyloxy groups having 2 to 27 carbon atoms, such as acetyloxy and propionyloxy. group, butyryloxy group, and the like. The alkoxycarbonyl group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The alkylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The alkylcarbonyloxy group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms.
The alkylsulfonyl group includes alkylsulfonyl groups having 1 to 27 carbon atoms, such as methylsulfonyl, ethylsulfonyl and propylsulfonyl groups. The alkylsulfonyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The alkanediyloxy group includes alkanediyloxy groups having 1 to 27 carbon atoms, such as methyleneoxy, ethyleneoxy, propanediyloxy, butanediyloxy, and pentanediyloxy groups. The alkanediyloxy group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The alkanediyloxycarbonyl group includes an alkanediyloxycarbonyl group having 2 to 27 carbon atoms, such as a methyleneoxycarbonyl group, an ethyleneoxycarbonyl group, a propanediyloxycarbonyl group, a butanediyloxycarbonyl group, and the like. . The alkanediylcarbonyl group includes alkanediylcarbonyl groups having 2 to 28 carbon atoms, such as methylenecarbonyl, ethylenecarbonyl, propanediylcarbonyl, butanediylcarbonyl and pentanediylcarbonyl groups. The alkanediylcarbonyloxy group includes an alkanediylcarbonyloxy group having 2 to 27 carbon atoms, such as a methylenecarbonyloxy group, an ethylenecarbonyloxy group, a propanediylcarbonyloxy group, a butanediylcarbonyloxy group, and the like. . The alkanediyloxycarbonyl group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The alkanediylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The alkanediylcarbonyloxy group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms.
The alkanediylthio group includes alkanediylthio groups having 1 to 27 carbon atoms, such as methylenethio, ethylenethio and propanediylthio groups. The alkanediylthio group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The alkanediylsulfonyl group includes alkanediylsulfonyl groups having 1 to 27 carbon atoms, such as methylenesulfonyl, ethylenesulfonyl and propylenesulfonyl groups. The alkanediylsulfonyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.

具体的に、脂環式炭化水素基としては、以下の脂環式炭化水素基等が挙げられる。結合部位は任意の位置とすることができる。

芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニル基、フェナントリル基等のアリール基が挙げられる。芳香族炭化水素基の炭素数は、好ましくは６～１４であり、より好ましくは６～１０である。
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が有してもよい置換基は、ハロゲン原子、ヒドロキシ基、炭素数１～３のアルキル基、炭素数１～３のアルコキシ基、炭素数１～３のハロアルキル基等が挙げられる。
Ｌ^１における鎖状の炭化水素基が有していてもよい置換基としては、ハロゲン原子、炭素数１～４のハロアルキル基、炭素数１～１２のアルキル基（該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。）、炭素数３～１８の脂環式炭化水素基（該脂環式炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。該脂環式炭化水素基は、置換基を有してもよい。）又は炭素数６～１８の芳香族炭化水素基（該芳香族炭化水素基は、置換基を有してもよい。）が好ましく、フッ素原子、ヨウ素原子、炭素数１～３のハロアルキル基、炭素数１～８のアルキル基（該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。）、炭素数３～１２の脂環式炭化水素基（該脂環式炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。該脂環式炭化水素基は、置換基を有してもよい。）又は炭素数６～１０の芳香族炭化水素基（該芳香族炭化水素基は、置換基を有してもよい。）がより好ましく、炭素数１～６のアルキル基、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、デカヒドロナフチル基、アダマンチル基、ノルボルニル基又はフェニル基がさらに好ましい。
Ｌ^１は、置換基を有していてもよい炭素数１～１２の鎖式炭化水素基であることが好ましく、炭素数１～１２の鎖式炭化水素基であることがより好ましく、炭素数２～１０の鎖式炭化水素基であることがさらに好ましい。 The chain hydrocarbon group in L ¹ may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 6 carbon atoms, and an alkyl group having 1 to 12 carbon atoms (-CH ₂ - contained in the alkyl group is replaced with -O- or -CO-). ), an alicyclic hydrocarbon group having 3 to 18 carbon atoms (-CH ₂ - contained in the alicyclic hydrocarbon group may be replaced with -O- or -CO-. The cyclic hydrocarbon group may have a substituent.) or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group may have a substituent.), etc. mentioned.
Halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
The chain hydrocarbon group in L ¹ can substantially have a substituent such as a haloalkyl group by having a halogen atom as a substituent. The haloalkyl group includes chloromethyl group, bromomethyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, perfluorobutyl group and the like, preferably a haloalkyl group having 1 to 4 carbon atoms, and a haloalkyl group having 1 to 3 carbon atoms. groups are more preferred.
Since the chain hydrocarbon group of L ¹ contains a branched structure, L ¹ can substantially have a substituent such as an alkyl group. Alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. is.
L ¹ is substantially a hydroxy group, a carboxy group, an alkoxy group, or an alkoxycarbonyl group due to the group in which —CH ₂ — contained in the chain hydrocarbon group of L ¹ is replaced with —O— or —CO— , an alkylcarbonyl group, an alkylcarbonyloxy group, and the like.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Monocyclic alicyclic hydrocarbon groups include monocyclic cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl groups, adamantyl groups, norbornyl groups, and polycyclic cycloalkyl groups such as the following groups (* represents a bonding site). The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms, more preferably 3 to 12 carbon atoms.

Specific examples of the alicyclic hydrocarbon group include the following alicyclic hydrocarbon groups. The binding site can be at any position.

Aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6-14, more preferably 6-10.
Substituents which the alicyclic hydrocarbon group having 3 to 18 carbon atoms or the aromatic hydrocarbon group having 6 to 18 carbon atoms may have include halogen atoms, hydroxy groups, alkyl groups having 1 to 3 carbon atoms, carbon Examples include alkoxy groups having 1 to 3 carbon atoms and haloalkyl groups having 1 to 3 carbon atoms.
Examples of substituents that the chain hydrocarbon group in L ¹ may have include a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 12 carbon atoms (the —CH _2- may be replaced with -O- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms (-CH ₂ - contained in the alicyclic hydrocarbon group is - O— or —CO—.The alicyclic hydrocarbon group may have a substituent.) or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group may have a substituent) is preferred, and a fluorine atom, an iodine atom, a haloalkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 8 carbon atoms (the —CH ₂ — may be replaced with -O- or -CO-), an alicyclic hydrocarbon group having 3 to 12 carbon atoms (-CH ₂ - contained in the alicyclic hydrocarbon group is -O- or —CO—.The alicyclic hydrocarbon group may have a substituent.) or an aromatic hydrocarbon group having 6 to 10 carbon atoms (the aromatic hydrocarbon group is , which may have a substituent) is more preferable, and an alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a decahydronaphthyl group, an adamantyl group, a norbornyl group or a phenyl group is more preferred.
L ¹ is preferably an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms, more preferably a chain hydrocarbon group having 1 to 12 carbon atoms, and 2 to 10 chain hydrocarbon groups are more preferred.

［式（Ｉ－１）中、
Ｒ^１、Ｘ^１、Ｒ^２、Ｒ^３は、式（Ｉ）と同じものを表す。
Ｌ^１０は、単結合又は炭素数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－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わってもよい。ｍｉ１が２以上の場合、複数のＬ^１０は、互いに同じであっても異なっていてもよい。
Ｒ^１０は、水素原子、炭素数１～１２のアルキル基、炭素数３～１８の脂環式炭化水素基（該脂環式炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。該脂環式炭化水素基は、置換基を有していてもよい。）又は炭素数６～１８の芳香族炭化水素基（該芳香族炭化水素基は、置換基を有してもよい。）を表す。ｍｉ２が２以上の場合、複数のＲ^１０は、互いに同じであっても異なっていてもよい。
ｍｉ１は、１～３のいずれかの整数を表す。
ｍｉ２は、３－ｍｉ１を満たす整数を表す。］
Ｌ^１０のアルカンジイル基は、炭素数の上限が許す限り、Ｌ^１に挙げられたアルカンジイル基と同じ基が挙げられる。
Ｒ^１０の炭素数１～１２のアルキル基は、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、ｔｅｒｔ－ブチル基、ペンチル基、ヘキシル基、ヘプチル基、２－エチルヘキシル基、オクチル基、ノニル基、デシル基、ウンデシル基及びドデシル基等が挙げられる。アルキル基の炭素数は、好ましくは１～１０であり、より好ましくは１～８であり、さらに好ましくは１～６であり、より一層好ましくは１～４であり、さらに一層好ましくは１～３である。
Ｒ^１０の炭素数３～１８の脂環式炭化水素基及び炭素数６～１８の芳香族炭化水素基は、それぞれＬ^１の置換基として挙げられた炭素数３～１８の脂環式炭化水素基及び炭素数６～１８の芳香族炭化水素基と同じ基が挙げられる。
Ｌ^１０は、単結合又は炭素数１～３のアルカンジイル基が好ましく、単結合、メチレン基又はエチレン基がより好ましい。
Ｒ^１０は、水素原子、炭素数１～８のアルキル基、炭素数３～１２の脂環式炭化水素基（該脂環式炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。該脂環式炭化水素基は、置換基を有してもよい。）又は炭素数６～１０の芳香族炭化水素基（該芳香族炭化水素基は、置換基を有してもよい。）が好ましく、水素原子、炭素数１～６のアルキル基、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、デカヒドロナフチル基、アダマンチル基、ノルボルニル基又はフェニル基がより好ましい。
ｍｉ１は、１又は２が好ましい。
ｍｉ２が１の場合、Ｒ^１０は水素原子であることが好ましく、ｍｉ２が２以上の場合、２以上のＲ^１０のうち少なくとも一つは水素原子であることが好ましい。 Examples of the fluorinated alkyl group having 1 to 8 carbon atoms for R ² include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group and a 2,2,2-trifluoroethyl group. group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1-(trifluoromethyl)- 1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1 , 2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis(trifluoro)methyl-2,2,2-trifluoroethyl group, 2-(perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoro pentyl group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2-(perfluorobutyl)ethyl group, 1,1,2,2, 3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group , perfluorohexyl group, perfluoroheptyl group, and perfluorooctyl group. The fluorinated alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 5 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The fluorinated alkyl group having 1 to 6 carbon atoms for R ³ is the same as the fluorinated alkyl group having 1 to 6 carbon atoms exemplified for the fluorinated alkyl group for R ² as long as the upper limit of the carbon number permits. be done.
When R ³ is a fluorinated alkyl group having 1 to 6 carbon atoms, R ² is preferably a fluorinated alkyl group having 1 to 6 carbon atoms, more preferably a fluorinated alkyl group having 1 to 3 carbon atoms. , more preferably a trifluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, and still more preferably a trifluoromethyl group.
When R ³ is a hydrogen atom, R ² is preferably a fluorinated alkyl group having 1 to 6 carbon atoms, more preferably a fluorinated alkyl group having 1 to 5 carbon atoms, still more preferably 3 to 3 carbon atoms. 5 is a fluorinated alkyl group.
R ³ is preferably a hydrogen atom or a fluorinated alkyl group having 1 to 3 carbon atoms.
mi is preferably an integer of 1 to 3, more preferably 1 or 2, even more preferably 1.
Structural unit (I) is also preferably a structural unit represented by formula (I-1) (hereinafter sometimes referred to as “structural unit (I-1)”).

[In the formula (I-1),
R ¹ , X ¹ , R ² and R ³ represent the same as in formula (I).
L ¹⁰ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and —CH ₂ — contained in the alkanediyl group may be replaced with —O— or —CO—. When mi1 is 2 or more, a plurality of ^L10 may be the same or different.
R ¹⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms (-CH ₂ - contained in the alicyclic hydrocarbon group is -O- or - may be substituted with CO—.The alicyclic hydrocarbon group may have a substituent.) or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group is may have a substituent). When mi2 is 2 or more, multiple R ¹⁰ may be the same or different.
mi1 represents an integer of 1 to 3;
mi2 represents an integer that satisfies 3-mi1. ]
The alkanediyl group for L ¹⁰ includes the same alkanediyl groups for L ¹ as long as the upper limit of the number of carbon atoms permits.
The alkyl group having 1 to 12 carbon atoms for R ¹⁰ is a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group. , 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. is.
The alicyclic hydrocarbon group having 3 to 18 carbon atoms and the aromatic hydrocarbon group having 6 to 18 carbon atoms for R ¹⁰ are the alicyclic hydrocarbon groups having 3 to 18 carbon atoms listed as substituents for L ¹ , respectively. group and the same group as the aromatic hydrocarbon group having 6 to 18 carbon atoms.
L ¹⁰ is preferably a single bond or an alkanediyl group having 1 to 3 carbon atoms, more preferably a single bond, a methylene group or an ethylene group.
R ¹⁰ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms (-CH ₂ - contained in the alicyclic hydrocarbon group is -O- or - may be substituted with CO—.The alicyclic hydrocarbon group may have a substituent.) or an aromatic hydrocarbon group having 6 to 10 carbon atoms (the aromatic hydrocarbon group may be substituted A hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a decahydronaphthyl group, an adamantyl group, a norbornyl group. Or a phenyl group is more preferable.
mi1 is preferably 1 or 2.
When mi2 is 1, R ¹⁰ is preferably a hydrogen atom, and when mi2 is 2 or more, at least one of 2 or more R ¹⁰ is preferably a hydrogen atom.

Structural units (I) include the following structural units.

In the above structural unit, the methyl group corresponding to R ¹ is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group, and the hydrogen atom corresponding to R ¹ is a halogen atom, a haloalkyl group or an alkyl group Structural units replaced with can also be cited as specific examples of the structural unit (I).

［式（Ｉ’）中、Ｒ^１、Ｘ^１、Ｌ^１、Ｒ^２、Ｒ^３及びｍｉは、上記と同じ意味を表す。］
化合物（Ｉ’）は、市販品であってもよいし、公知の方法で製造したものでもよい。 Structural unit (I) is derived from a compound represented by formula (I') (hereinafter sometimes referred to as "compound (I')").

[In Formula (I′), R ¹ , X ¹ , L ¹ , R ² , R ³ and mi represent the same meanings as above. ]
Compound (I') may be a commercial product or one produced by a known method.

［式（ＩＩＩ）中、
Ｒ^４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。
Ｘ^２は、単結合又は＊－ＣＯ－Ｏ－を表す。＊は、Ｒ^４が結合する炭素原子との結合部位を表す。
Ｌ^２は、単結合又は置換基を有していてもよい炭素数１～２８の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
ｍｋは、１～４のいずれかの整数を表す。］ Resin (A1) contains a structural unit represented by formula (III) (hereinafter sometimes referred to as “structural unit (III)”).

[in the formula (III),
R ⁴ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
^X2 represents a single bond or *-CO-O-. * represents the binding site to the carbon atom to which ^R4 binds.
L ² represents a single bond or an optionally substituted hydrocarbon group having 1 to 28 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —S—, — SO ₂ - or -CO- may be substituted.
mk represents an integer of 1-4. ]

Examples of the alkyl group having 1 to 6 carbon atoms, the halogen atom and the alkyl group having 1 to 6 carbon atoms having a halogen atom for R ⁴ are the same as those for R ¹ .
R ⁴ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, a hydrogen atom or a methyl group is even more preferred.
The hydrocarbon group for ^L2 includes a chain hydrocarbon group, a monocyclic or polycyclic (including spiro ring, condensed ring or bridged ring, etc.) alicyclic hydrocarbon group, aromatic hydrocarbon group, and the like. and a group in which two or more of these groups are combined (e.g., a hydrocarbon group formed from an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group) It's okay.
Examples of chain hydrocarbon groups include divalent to pentavalent chain hydrocarbon groups such as alkanediyl groups, alkanetriyl groups, alkanetetrayl groups, and alkanepentyl groups.
The alkanediyl groups include methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, 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 linear groups such as tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl and heptadecane-1,17-diyl alkanediyl group and 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, Branched alkanediyl groups such as 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2-methylbutane-1,4-diyl group is mentioned.
Alkanetriyl groups include methanetriyl, ethanetriyl, propanetriyl, butanetriyl, pentanetriyl, hexanetriyl, heptanetriyl, octanetriyl, nonanetriyl, decanetriyl, and undecanetriyl groups. , dodecanetriyl group, tridecanetriyl group, tetradecanetriyl group, pentadecanetriyl group, hexadecanetriyl group and heptadecanetriyl group.
The alkanetetrayl group includes a methantetrayl group, an ethanetetrayl group, a propanetetrayl group, a butanetetrayl group, a pentanetetrayl group, a hexanetetrayl group, a heptanetetrayl group, an octanetetrayl group, and a nonanetetrayl group. group, decanetetrayl group, undecanetetrayl group, dodecanetetrayl group, tridecanetetrayl group, tetradecanetetrayl group, pentadecanetetrayl group, hexadecanetetrayl group and heptadecanetetrayl group.
Also included are groups in which one or more of the hydrogen atoms of the above groups are replaced with bonding sites.
The chain hydrocarbon group preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 10 carbon atoms, still more preferably 1 to 9 carbon atoms, and still more preferably 1 to 8, even more preferably 1 to 6, even more preferably 1 to 5, and particularly preferably 1 to 4.

例えば、シクロアルカンジイル基、シクロアルカントリイル基、シクロアルカンテトライル基、シクロアルカンペンタイル基等の２～５価の脂環式炭化水素基等が挙げられる。
具体的には、シクロブタン－１，３－ジイル基、シクロペンタン－１，３－ジイル基、シクロヘキサン－１，４－ジイル基、シクロオクタン－１，５－ジイル基、シクロプロパントリイル基、シクロブタントリイル基、シクロペンタントリイル基、シクロヘキサントリイル基、シクロヘプタントリイル基、シクロオクタントリイル基、シクロデカントリイル基、シクロプロパンテトライル基、シクロブタンテトライル基、シクロペンタンテトライル基、シクロヘキサンテトライル基、シクロヘプタンテトライル基、シクロオクタンテトライル基、シクロデカンテトライル基等の単環式の脂環式炭化水素基及び
ノルボルナン－１，４－ジイル基、ノルボルナン－２，５－ジイル基、アダマンタン－１，５－ジイル基、アダマンタン－２，６－ジイル基、デカヒドロナフタレンジイル基、ビシクロ[３．３．０]オクタンジイル基、ノルボルナントリイル基、アダマンタントリイル基、デカヒドロナフタレントリイル基、ビシクロ[３．３．０]オクタントリイル基、ノルボルナンテトライル基、アダマンタンテトライル基、デカヒドロナフタレンテトライル基、ビシクロ[３．３．０]オクタンテトライル基等の多環式の脂環式炭化水素基が挙げられる。
また、上述した基の水素原子の１つ以上を結合部位に置き換えた基等も挙げられる。
脂環式炭化水素基の炭素数は、好ましくは３～２０であり、より好ましくは３～１８であり、さらに好ましくは３～１６であり、さらにより好ましくは３～１２である。
芳香族炭化水素基としては、アリーレン基、アレーントリイル基、アレーンテトライル基、アレーンペンタイル基等の２～５価の芳香族炭化水素基等が挙げられる。
具体的には、フェニレン基、ナフチレン基、アントリレン基、ビフェニレン基、フェナントリレン基、ベンゼントリイル基、ナフタレントリイル基、アントラセントリイル基、ビフェニレントリイル基、フェナントレントリイル基、ベンゼンテトライル基、ナフタレンテトライル基、アントラセンテトライル基、ビフェニレンテトライル基、フェナントレンテトライル基等の芳香族炭化水素基が挙げられる。
また、上述した基の水素原子の１つ以上を結合部位に置き換えた基等も挙げられる。
芳香族炭化水素基の炭素数は、好ましくは６～２０であり、より好ましくは６～１８であり、さらに好ましくは６～１４であり、さらにより好ましくは６～１０である。 Examples of monocyclic or polycyclic alicyclic hydrocarbon groups include the following alicyclic hydrocarbon groups. The binding site can be at any position.

Examples thereof include divalent to pentavalent alicyclic hydrocarbon groups such as a cycloalkanediyl group, cycloalkanetriyl group, cycloalkanetetrayl group and cycloalkanepentyl group.
Specifically, cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, cyclopropanetriyl group, cyclobutane triyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclodecanetriyl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexane monocyclic alicyclic hydrocarbon groups such as a tetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclodecanetetrayl group and norbornane-1,4-diyl group, norbornane-2,5-diyl adamantane-1,5-diyl group, adamantane-2,6-diyl group, decahydronaphthalenediyl group, bicyclo[3.3.0]octanediyl group, norbornanetriyl group, adamantanetriyl group, decahydro Polycyclic groups such as a naphthalenetriyl group, a bicyclo[3.3.0]octanetriyl group, a norbornanetetrayl group, an adamantanetetrayl group, a decahydronaphthalenetetrayl group, and a bicyclo[3.3.0]octanetetrayl group and alicyclic hydrocarbon groups of the formula:
Also included are groups in which one or more hydrogen atoms of the above groups are replaced with bonding sites.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 18 carbon atoms, still more preferably 3 to 16 carbon atoms, and still more preferably 3 to 12 carbon atoms.
Examples of the aromatic hydrocarbon group include divalent to pentavalent aromatic hydrocarbon groups such as arylene group, arenetriyl group, arenetetrayl group and arenepentyl group.
Specifically, phenylene group, naphthylene group, anthrylene group, biphenylene group, phenanthrylene group, benzenetriyl group, naphthalenetriyl group, anthracentriyl group, biphenylenetriyl group, phenanthrenetriyl group, benzenetetrayl group, Aromatic hydrocarbon groups such as a naphthalenetetrayl group, anthracenetetrayl group, a biphenylenetetrayl group, and a phenanthrenetetrayl group can be mentioned.
Also included are groups in which one or more hydrogen atoms of the above groups are replaced with bonding sites.
The number of carbon atoms in the aromatic hydrocarbon group is preferably 6-20, more preferably 6-18, still more preferably 6-14, still more preferably 6-10.

脂環式炭化水素基と鎖式炭化水素基と芳香族炭化水素基とを組み合わせた基としては、脂環式炭化水素基に１以上の芳香族炭化水素基と鎖式炭化水素基が結合した基（例えば、＊－脂環式炭化水素基－芳香族炭化水素基－（鎖式炭化水素基－）_ｍｋ等）、芳香族炭化水素基に１以上の脂環式炭化水素基と鎖式炭化水素基が結合した基（例えば、＊－芳香族炭化水素基－脂環式炭化水素基－（鎖式炭化水素基－）_ｍｋ等）等が挙げられる。
＊はＸ^２との結合部位を表す。 Groups in which two or more types are combined include a group in which an alicyclic hydrocarbon group and a chain hydrocarbon group are combined, a group in which an aromatic hydrocarbon group and a chain hydrocarbon group are combined, and an alicyclic hydrocarbon group. A group obtained by combining a group and an aromatic hydrocarbon group, a group obtained by combining an alicyclic hydrocarbon group, a chain hydrocarbon group and an aromatic hydrocarbon group, and the like. Combination WHEREIN: An alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a chain hydrocarbon group may combine 2 or more types, respectively. Also, any group may be bonded to ^X2 .
Groups in which an alicyclic hydrocarbon group and a chain hydrocarbon group are combined include, for example, a group in which one or more alicyclic hydrocarbon groups are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group -(alicyclic hydrocarbon group-) _mk , etc.), groups in which one or more chain hydrocarbon groups are bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-(chain chain hydrocarbon hydrogen group-) _mk , etc.), a group in which one or more alicyclic hydrocarbon groups and a chain hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-(alicyclic hydrocarbon group-chain hydrocarbon group-) _mk , *-chain hydrocarbon group-alicyclic hydrocarbon group-(chain hydrocarbon group-) _mk , etc.), one or more chain groups in an alicyclic hydrocarbon group A group in which a hydrocarbon group and an alicyclic hydrocarbon group are bonded (e.g., *-alicyclic hydrocarbon group-(chain hydrocarbon group-alicyclic hydrocarbon group-) _mk , *-alicyclic hydrocarbon group-chain hydrocarbon group-(alicyclic hydrocarbon group-) _mk , etc.), a chain hydrocarbon group containing one or more alicyclic hydrocarbon groups, a chain hydrocarbon group and an alicyclic hydrocarbon group Bonded groups (for example, *-chain hydrocarbon group-alicyclic hydrocarbon group-(chain hydrocarbon group-alicyclic hydrocarbon group-) _mk , *-chain hydrocarbon group-alicyclic hydrocarbon Hydrogen group-chain hydrocarbon group-(alicyclic hydrocarbon group-) _mk , etc.), alicyclic hydrocarbon group with one or more chain hydrocarbon groups and alicyclic hydrocarbon group and chain hydrocarbon group is bonded to a group (e.g., *-alicyclic hydrocarbon group-(chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-) _mk , *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-(chain hydrocarbon group-), _mk , etc.).
Groups in which an aromatic hydrocarbon group and a chain hydrocarbon group are combined include, for example, a group in which one or more aromatic hydrocarbon groups are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group- (aromatic hydrocarbon group-) _mk , etc.), groups in which one or more chain hydrocarbon groups are bonded to an aromatic hydrocarbon group (e.g., *-aromatic hydrocarbon group-(chain hydrocarbon group-) _mk etc.), a group in which one or more aromatic hydrocarbon groups and a chain hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-(aromatic hydrocarbon group-chain hydrocarbon group -) _mk , *-chain hydrocarbon group-aromatic hydrocarbon group-(chain hydrocarbon group-) _mk , etc.).
Groups in which an alicyclic hydrocarbon group and an aromatic hydrocarbon group are combined include groups in which one or more aromatic hydrocarbon groups are bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group -(aromatic hydrocarbon group-) _mk , etc.), a group in which one or more alicyclic hydrocarbon groups are bonded to an aromatic hydrocarbon group (e.g., *-aromatic hydrocarbon group-(alicyclic hydrocarbon group -) _mk , etc.), groups in which an alicyclic hydrocarbon group and an aromatic hydrocarbon group are condensed (for example, the following groups (bonding sites are at arbitrary positions), etc.), and the like.

As a group in which an alicyclic hydrocarbon group, a chain hydrocarbon group and an aromatic hydrocarbon group are combined, one or more aromatic hydrocarbon groups and chain hydrocarbon groups are bonded to an alicyclic hydrocarbon group group (for example, *-alicyclic hydrocarbon group-aromatic hydrocarbon group-(chain hydrocarbon group-) _mk , etc.), aromatic hydrocarbon group with one or more alicyclic hydrocarbon groups and chain carbonization Groups to which a hydrogen group is bonded (eg, *—aromatic hydrocarbon group—alicyclic hydrocarbon group—(chain hydrocarbon group—) _mk , etc.).
* represents the binding site with ^X2 .

--CH ₂ -- contained in the hydrocarbon group having 1 to 28 carbon atoms in L ² may be replaced with --O--, --S--, --SO ₂ -- or --CO--.
When —CH ₂ — contained in the hydrocarbon group having 1 to 28 carbon atoms of L ² is replaced with —O—, —S—, —SO ₂ — or —CO—, the number of carbon atoms before replacement is The number of carbon atoms in the hydrogen group.
The group in which —CH ₂ — contained in the hydrocarbon group is replaced by —O—, —S—, —SO ₂ — or —CO— includes a hydroxy group (the —CH ₂ — contained in the methyl group, -O-), carboxy group (group in which -CH ₂ -CH ₂ - contained in the ethyl group is replaced by -O-CO-), thiol group (-CH ₂ contained in the methyl group — is replaced with —S—), alkoxy group (group in which —CH ₂ — at any position in the alkyl group is replaced with —O—), alkylthio group (any -CH ₂ - at the position is replaced with -S-), alkoxycarbonyl group (group in which -CH ₂ -CH ₂ - at any position in the alkyl group is replaced with -O-CO- ), alkylsulfonyl group (a group in which —CH ₂ — at any position in the alkyl group is replaced with —SO ₂ —), alkylcarbonyl group ( —CH ₂ — at any position in the alkyl group) is replaced with -CO-), alkylcarbonyloxy group (group in which -CH ₂ -CH ₂ - at any position in the alkyl group is replaced with -CO-O-), oxy group (methylene -CH ₂ - contained in the group is replaced with -O-), carbonyl group (group in which the -CH ₂ - contained in the methylene group is replaced by -CO-), thio group (in the methylene group -CH ₂ - contained in is replaced by -S-), sulfonyl group (group in which -CH ₂ - contained in the methylene group is replaced by -SO ₂ -), alkanediyloxy group (alkanediyl a group in which —CH ₂ — at any position contained in the group is replaced with —O—), alkanediyloxycarbonyl group (where —CH ₂ —CH ₂ — at any position contained in the alkanediyl group —O—CO—), alkanediylcarbonyl group (group in which —CH ₂ — at any position in the alkanediyl group is replaced with —CO—), alkanediylcarbonyloxy group (alkanediyl a group in which —CH ₂ —CH ₂ — at any position contained in the group is replaced with —CO—O—), alkanediylsulfonyl group (where —CH ₂ — at any position contained in the alkanediyl group , a group substituted with -SO ₂ -), an alkanediylthio group (a group in which -CH ₂ - at any position in the alkanediyl group is substituted with -S-), a cycloalkoxy group, a cycloalkylalkoxy group , an alkoxycarbonyloxy group, an aromatic hydrocarbon group-carbonyloxy group, an aromatic hydrocarbon group-carbonyl group, an aromatic hydrocarbon group-oxy group, a combination of two or more of these groups, and the like. . Also included are groups in which one or more hydrogen atoms of these groups are replaced with bonding sites.
The alkoxy group includes alkoxy groups having 1 to 27 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy. group, decyloxy group, undecyloxy group, and the like. The alkoxy group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The alkylthio group includes alkylthio groups having 1 to 27 carbon atoms, such as methylthio, ethylthio, propylthio and butylthio groups. The alkylthio group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
An alkoxycarbonyl group, an alkylcarbonyl group and an alkylcarbonyloxy group represent groups in which a carbonyl group or a carbonyloxy group is bonded to the above alkyl group or alkoxy group.
The alkoxycarbonyl group includes alkoxycarbonyl groups having 2 to 27 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl and butoxycarbonyl groups. The alkylcarbonyl group includes alkylcarbonyl groups having 2 to 28 carbon atoms, such as acetyl group, propionyl group and butyryl group. The alkylcarbonyloxy group includes alkylcarbonyloxy groups having 2 to 27 carbon atoms, such as acetyloxy, propionyloxy and butyryloxy groups. The alkoxycarbonyl group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The alkylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The alkylcarbonyloxy group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms.
The alkylsulfonyl group includes alkylsulfonyl groups having 1 to 27 carbon atoms, such as methylsulfonyl, ethylsulfonyl and propylsulfonyl groups. The alkylsulfonyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The alkanediyloxy group includes alkanediyloxy groups having 1 to 27 carbon atoms, such as methyleneoxy, ethyleneoxy, propanediyloxy, butanediyloxy, and pentanediyloxy groups. The alkanediyloxy group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The alkanediyloxycarbonyl group includes an alkanediyloxycarbonyl group having 2 to 27 carbon atoms, such as a methyleneoxycarbonyl group, an ethyleneoxycarbonyl group, a propanediyloxycarbonyl group, a butanediyloxycarbonyl group, and the like. . The alkanediylcarbonyl group includes alkanediylcarbonyl groups having 2 to 28 carbon atoms, such as methylenecarbonyl, ethylenecarbonyl, propanediylcarbonyl, butanediylcarbonyl and pentanediylcarbonyl groups. The alkanediylcarbonyloxy group includes an alkanediylcarbonyloxy group having 2 to 27 carbon atoms, such as a methylenecarbonyloxy group, an ethylenecarbonyloxy group, a propanediylcarbonyloxy group, a butanediylcarbonyloxy group, and the like. . The alkanediyloxycarbonyl group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The alkanediylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The alkanediylcarbonyloxy group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms.
The alkanediylthio group includes alkanediylthio groups having 1 to 27 carbon atoms, such as methylenethio, ethylenethio and propanediylthio groups. The alkanediylthio group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The alkanediylsulfonyl group includes alkanediylsulfonyl groups having 1 to 27 carbon atoms, such as methylenesulfonyl, ethylenesulfonyl and propylenesulfonyl groups. The alkanediylsulfonyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms.

The cycloalkoxy group includes a cycloalkoxy group having 3 to 27 carbon atoms, such as a cyclohexyloxy group. The cycloalkylalkoxy group includes a cycloalkylalkoxy group having 4 to 27 carbon atoms, such as a cyclohexylmethoxy group. The alkoxycarbonyloxy group includes an alkoxycarbonyloxy group having 2 to 26 carbon atoms, such as a butoxycarbonyloxy group. The aromatic hydrocarbon group-carbonyloxy group includes an aromatic hydrocarbon group-carbonyloxy group having 7 to 27 carbon atoms, such as a benzoyloxy group. The aromatic hydrocarbon group-carbonyl group includes an aromatic hydrocarbon group-carbonyl group having 7 to 28 carbon atoms, such as a benzoyl group. The aromatic hydrocarbon group-oxy group includes an aromatic hydrocarbon group-oxy group having 6 to 27 carbon atoms, such as a phenyloxy group.

組み合わせた基に含まれる－ＣＨ_２－が、－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－で置き換わった基としては、以下の基等も挙げられる。結合部位は任意の位置とすることができる。

Ｌ^２における炭化水素基は、１又は複数の置換基を有していてもよい。該置換基としては、ハロゲン原子、炭素数１～６のハロアルキル基又は炭素数１～１２のアルキル基（該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。）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、ヨウ素原子等が挙げられる。
Ｌ^２における炭化水素基は、置換基としてハロゲン原子を有することで、実質的に、ハロアルキル基等の置換基を有することができる。ハロアルキル基は、クロロメチル基、ブロモメチル基、フルオロメチル基、ジフルオロメチル基、トリフルオロメチル基、ペルフルオロブチル基等が挙げられ、炭素数１～４のハロアルキル基が好ましく、炭素数１～３のハロアルキル基がより好ましい。
Ｌ^２の炭化水素基が分岐状の構造を含むことにより、Ｌ^２は、実質的に、アルキル基等の置換基を有することができる。アルキル基は、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、ｔｅｒｔ－ブチル基、ペンチル基、ヘキシル基、ヘプチル基、２－エチルヘキシル基、オクチル基、ノニル基、デシル基、ウンデシル基及びドデシル基等が挙げられる。アルキル基の炭素数は、好ましくは１～１０であり、より好ましくは１～８であり、さらに好ましくは１～６であり、より一層好ましくは１～４であり、さらに一層好ましくは１～３である。
Ｌ^２の炭化水素基に含まれる－ＣＨ₂－が－Ｏ－又は－ＣＯ－に置き換わった基により、Ｌ^２は、実質的に、ヒドロキシ基、カルボキシ基、アルコキシ基、アルコキシカルボニル基、アルキルカルボニル基、アルキルカルボニルオキシ基等の置換基を有することができる。
Ｌ^２における炭化水素基が有していてもよい置換基としては、ハロゲン原子、炭素数１～４のハロアルキル基又は炭素数１～６のアルキル基（該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。）が好ましく、フッ素原子、ヨウ素原子、炭素数１～３のハロアルキル基又は炭素数１～４のアルキル基（該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。）がより好ましく、フッ素原子、ヨウ素原子、トリフルオロメチル基、メチル基、ヒドロキシ基又はメトキシ基がさらに好ましい。 Examples of groups in which —CH ₂ — contained in the alicyclic hydrocarbon group is replaced with —O—, —S—, —CO— or —SO ₂ — include the following groups. Among the groups represented below, groups in which -O- is replaced with -S- and -CO- is replaced with -SO ₂ - are also included. The binding site can be at any position.

Groups in which —CH ₂ — contained in the combined group is replaced with —O—, —S—, —CO— or —SO ₂ — also include the following groups. The binding site can be at any position.

The hydrocarbon group in ^L2 may have one or more substituents. The substituent includes a halogen atom, a haloalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 12 carbon atoms (-CH ₂ - contained in the alkyl group is replaced with -O- or -CO- is also good.) and the like.
Halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
The hydrocarbon group in L ² can substantially have a substituent such as a haloalkyl group by having a halogen atom as a substituent. The haloalkyl group includes chloromethyl group, bromomethyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, perfluorobutyl group and the like, preferably a haloalkyl group having 1 to 4 carbon atoms, and a haloalkyl group having 1 to 3 carbon atoms. groups are more preferred.
Since the hydrocarbon group of L ² contains a branched structure, L ² can substantially have a substituent such as an alkyl group. Alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. is.
L ² is substantially a hydroxy group, a carboxy group, an ^alkoxy _group , an alkoxycarbonyl group, an alkylcarbonyl can have substituents such as groups, alkylcarbonyloxy groups, and the like.
Substituents that the hydrocarbon group in L ² may have include a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 6 carbon atoms (the —CH ₂ — contained in the alkyl group is , —O— or —CO—.) is preferred, and a fluorine atom, an iodine atom, a haloalkyl group having 1 to 3 carbon atoms or an alkyl group having 1 to 4 carbon atoms (included in the alkyl group- CH ₂ - may be replaced with -O- or -CO-) is more preferred, and a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group or a methoxy group is more preferred.

L ² is a single bond or an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms (with the proviso that —CH ₂ — contained in the chain hydrocarbon group is —O— or — may be substituted with CO-), an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (with the proviso that -CH ₂ - contained in the cyclic hydrocarbon group is -O- , —S—, —CO—, or —SO ₂ —.) or an optionally substituted chain hydrocarbon group having 1 to 8 carbon atoms and a substituent a group formed by combining a cyclic hydrocarbon group having 3 to 20 carbon atoms which is preferable (provided that —CH ₂ — contained in the chain hydrocarbon group may be replaced with —O— or —CO—; —CH ₂ — contained in the cyclic hydrocarbon group may be replaced with —O—, —S—, —SO ₂ — or —CO—), and has a substituent. a chain hydrocarbon group having 1 to 10 carbon atoms which may be substituted (provided that —CH ₂ — contained in the chain hydrocarbon group may be replaced with —O— or —CO—), substituents (with the proviso that —CH ₂ — contained in the cyclic hydrocarbon group is —O—, —S—, —CO— or —SO ₂ — ) Or a chain hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent and (provided that —CH ₂ — contained in the chain hydrocarbon group may be replaced by —O— or —CO—, and —CH ₂ — contained in the cyclic hydrocarbon group is , —O—, —S—, —SO ₂ —, or —CO—. Hydrogen group (with the proviso that —CH ₂ — contained in the chain hydrocarbon group may be replaced with —O— or —CO—) or optionally substituted C 3-16 (where -CH ₂ - contained in the cyclic hydrocarbon group may be replaced with -O- or -CO-), and is more preferably a cyclic hydrocarbon group having 1 to 9 carbon atoms, a chain hydrocarbon group (with the proviso that —CH ₂ — contained in the chain hydrocarbon group may be replaced with —O— or —CO—), an alicyclic hydrocarbon having 3 to 12 carbon atoms; groups (with the proviso that —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced with —O—, —S—, —CO— or —SO ₂ —. ) or an aromatic hydrocarbon group having 6 to 10 carbon atoms (wherein the aromatic hydrocarbon group is 1 or more halogen atoms, 1 or more alkyl groups having 1 to 3 carbon atoms, 1 or more carbon atoms of 1 to 3 or one or more alkoxy groups having 1 to 3 carbon atoms.) is more preferably a chain hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 carbon atoms a hydrogen group (the aromatic hydrocarbon group may have one or more halogen atoms, one or more alkyl groups having 1 to 3 carbon atoms, or one or more alkoxy groups having 1 to 3 carbon atoms); is even more preferred.
L ² is *-L ²² (-) mk or *-L ²² (-X ²³ -L ²³ -) mk (L ²² is a chain formula having 1 to 10 carbon atoms which may have a substituent A hydrocarbon group, an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms or an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms and optionally having a substituent -CH ₂ - contained in the cyclic hydrocarbon group is either -O-, -S-, -CO- or -SO ₂ -. —CH ₂ — contained in the chain hydrocarbon group may be replaced with —O— or —CO—, * represents a bonding site with X ^2. X ²³ is , **-CO-O-, **-O-CO-, **-O-CO-O- or **-O-, where ** represents the binding site with L ^22. L ²³ represents a single bond or an optionally substituted chain hydrocarbon group having 1 to 6 carbon atoms, and —CH ₂ — contained in the chain hydrocarbon group is —O— or —CO— may be replaced.) is also preferred.
The combination of a chain hydrocarbon group and a cyclic hydrocarbon group is *-chain hydrocarbon group-alicyclic hydrocarbon group or aromatic hydrocarbon group-, *-alicyclic hydrocarbon group or aromatic hydrocarbon group group-chain hydrocarbon group-, *-chain hydrocarbon group-alicyclic hydrocarbon group or aromatic hydrocarbon group-chain hydrocarbon group-, and the like. * represents the binding site with ^X2 .
Examples of the substituent that each group may have include the same groups as those exemplified as the substituent that L ² may have.
The cyclic hydrocarbon group for L ²² includes an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a condensed group thereof, and the like, and includes the same groups as those exemplified for L ² .
Examples of chain hydrocarbon groups for L ²² and L ²³ include the same groups as those exemplified for L ² .
L ²² is an optionally substituted chain hydrocarbon group having 1 to 9 carbon atoms (-CH ₂ - contained in the chain hydrocarbon group is replaced with -O- or -CO- ), an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (the —CH ₂ — contained in the cyclic hydrocarbon group is —O—, —S—, —CO— or —SO ₂ —.) or an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms and a chain hydrocarbon group having 1 to 4 carbon atoms optionally having substituents. (-CH ₂ - contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO ₂ -, and the chain hydrocarbon group The —CH ₂ — contained in may be replaced with —O— or —CO—.) is preferred, and an optionally substituted chain hydrocarbon group having 1 to 9 carbon atoms (the chain —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—) or a cyclic hydrocarbon group having 3 to 16 carbon atoms which may have a substituent (the cyclic hydrocarbon group may be —CH ₂ — contained in the hydrogen group may be replaced with —O— or —CO—.) is more preferable, and a chain hydrocarbon group having 1 to 6 carbon atoms which may have a substituent ( —CH ₂ — contained in the chain hydrocarbon group may be replaced with —O— or —CO—) or a cyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent ( —CH ₂ — contained in the cyclic hydrocarbon group may be replaced with —O— or —CO—.) is more preferred.
L ²³ is preferably a single bond or an optionally substituted chain hydrocarbon group having 1 to 4 carbon atoms, more preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms, a single bond, A methylene group or an ethylene group is more preferred, and a single bond or a methylene group is even more preferred.
mk is preferably an integer of 1 to 3, preferably 1 or 2.

Examples of the structural unit (III) include the following structural units and the structural unit (a2) described later.

In the above structural unit, the methyl group corresponding to ^R4 is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group, and the hydrogen atom corresponding to ^R4 is a halogen atom, a haloalkyl group or an alkyl group Structural units replaced with can also be cited as specific examples of the structural unit (III).

［式（ＩＩＩ’）中、Ｒ^４、Ｘ^２、Ｌ^２及びｍｋは、上記と同じ意味を表す。］
化合物（ＩＩＩ’）は、市販品であってもよいし、公知の方法で製造したものでもよい。 Structural unit (III) is derived from a compound represented by formula (III') (hereinafter sometimes referred to as "compound (III')").

[In formula (III′), R ⁴ , X ² , L ² and mk have the same meanings as above. ]
Compound (III') may be a commercial product or one produced by a known method.

The content of the structural unit (I) in the resin (A1) is preferably 5 mol% or more, more preferably 10 mol% or more, and still more preferably 20 mol% or more, based on the total structural units of the resin (A1). , more preferably 25 mol % or more, and even more preferably 30 mol % or more. Also, it is preferably 95 mol % or less, more preferably 90 mol % or less, even more preferably 80 mol % or less, still more preferably 75 mol % or less, and even more preferably 70 mol % or less. Also, it is preferably 5 to 95 mol %, more preferably 10 to 90 mol %, still more preferably 20 to 80 mol %, even more preferably 25 to 75 mol %, and even more preferably 30 to 70 mol %.
The content of the structural unit (III) in the resin (A1) is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 20 mol% or more, relative to the total structural units of the resin (A1). , more preferably 25 mol % or more, and even more preferably 30 mol % or more. Also, it is preferably 95 mol % or less, more preferably 90 mol % or less, even more preferably 80 mol % or less, still more preferably 75 mol % or less, and even more preferably 70 mol % or less. Also, it is preferably 5 to 95 mol %, more preferably 10 to 90 mol %, still more preferably 20 to 80 mol %, even more preferably 25 to 75 mol %, and even more preferably 30 to 70 mol %.
In the resin (A1), the total content of structural units (I) and structural units (III) is preferably 20 mol% or more, more preferably 30 mol% or more, based on the total of all structural units in resin (A1). It is preferably 40 mol % or more, more preferably 50 mol % or more, and even more preferably 60 mol % or more. Moreover, 100 mol% or less is mentioned. Specifically, it is preferably 20 to 100 mol%, more preferably 30 to 100 mol%, even more preferably 40 to 100 mol%, even more preferably 50 to 100 mol%, and even more preferably 60 to 100 mol%. .
The structural ratio of the structural unit (I) to the structural unit (III) in the resin (A1) is preferably in the range of 10:90 to 90:10, more preferably 30:70 to 70:30. .
When the content of the structural unit (I) and the structural unit (III) is within the above range, a resist pattern with excellent CD uniformity (CDU) can be produced, and in particular, a resist pattern with few defects can be produced. can.

Each structural unit (I) and structural unit (III) constituting the resin (A1) may be used alone or in combination of two or more. The resin (A1) may contain a structural unit having an acid-labile group, which will be described later, but the content of the structural unit having an acid-labile group in the resin (A1) is It is preferably 5 mol % or less, more preferably 0 mol %, relative to the unit. That is, the resin (A1) preferably does not contain a structural unit having an acid labile group. The resin (A1) may contain a structural unit having no acid-labile group, which will be described later. In the resin (A1), the content of structural units having no acid-labile group is preferably 80 mol% or less, more preferably 70 mol% or less, relative to the total of all structural units in the resin (A1). , is more preferably 60 mol % or less, even more preferably 50 mol % or less, and even more preferably 40 mol % or less. The resin (A1) is a combination of one or more monomers each from which the structural unit (I) and the structural unit (III) are derived, and optionally one kind such as a monomer having no acid-labile group, which will be described later. By combining the above, it can be produced by a known polymerization method (for example, radical polymerization method).
The weight average molecular weight of the resin (A1) is preferably 5,000 or more (more preferably 6,000 or more, still more preferably 7,000 or more) and 80,000 or less (more preferably 50,000 or less, further preferably is 30,000 or less). The weight-average molecular weight is determined by gel permeation chromatography analysis as a conversion value based on standard polystyrene standards, and detailed analysis conditions for the analysis will be described in detail in Examples of the present application.

<Resin (A2)>
Resin (A2) is a resin containing a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). The resin (A2) preferably further contains a structural unit other than the structural unit (a1). Structural units other than the structural unit (a1) include structural units having no acid-labile group (hereinafter sometimes referred to as "structural unit (s)"), structural units other than the structural unit (a1) and the structural unit (s). Structural units (for example, a structural unit having a halogen atom described later (hereinafter sometimes referred to as "structural unit (a4)"), a structural unit having a non-eliminating hydrocarbon group described later (hereinafter referred to as "structural unit (a5)" in some cases) and other structural units derived from monomers known in the art, etc. The resin (A2) may contain the structural unit (III) described above.

［式（１）中、Ｒ^ａ１、Ｒ^ａ２及びＲ^ａ３は、それぞれ独立に、炭素数１～８のアルキル基、炭素数２～８のアルケニル基、炭素数３～２０の脂環式炭化水素基、炭素数６～１８の芳香族炭化水素基又はこれらを組み合わせた基を表すか、Ｒ^a1及びＲ^a2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の非芳香族炭化水素環を形成する。
ｍａ及びｎａは、それぞれ独立して、０又は１を表し、ｍａ及びｎａの少なくとも一方は１を表す。
＊は結合部位を表す。］

［式（２）中、Ｒ^ａ１’及びＲ^ａ２’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^ａ３’は、炭素数１～２０の炭化水素基を表すか、Ｒ^ａ２’及びＲ^ａ３’は互いに結合してそれらが結合する炭素原子及びＸとともに炭素数３～２０の複素環を形成し、該炭化水素基及び該複素環に含まれる－ＣＨ_２－は、－Ｏ－又は－Ｓ－で置き換わってもよい。
Ｘは、酸素原子又は硫黄原子を表す。
ｎａ’は、０又は１を表す。
＊は結合部位を表す。］ <Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid-labile group (hereinafter sometimes referred to as "monomer (a1)").
The acid-labile group contained in the resin (A2) is a group represented by formula (1) (hereinafter also referred to as group (1)) and/or a group represented by formula (2) (hereinafter referred to as group (2 )) is preferred.

[In the formula (1), R ^a1 , R ^a2 and R ^a3 are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon having 3 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms or a combination thereof, or R ^a1 and R ^a2 are bonded to each other and together with the carbon atom to which they are bonded, a non-aromatic hydrocarbon group having 3 to 20 carbon atoms. Form a hydrogen ring.
ma and na each independently represent 0 or 1, and at least one of ma and na represents 1;
* represents a binding site. ]

[In formula (2), R ^a1′ and R ^a2′ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^a3′ represents a hydrocarbon group having 1 to 20 carbon atoms. or R ^a2′ and R ^a3′ are bonded to each other to form a heterocyclic ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and —CH ₂ contained in the hydrocarbon group and the heterocyclic ring - may be replaced by -O- or -S-.
X represents an oxygen atom or a sulfur atom.
na' represents 0 or 1;
* represents a binding site. ]

Ｒ^ａ１、Ｒ^ａ２及びＲ^ａ３における芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニル基、フェナントリル基等のアリール基が挙げられる。
組み合わせた基としては、上述したアルキル基と脂環式炭化水素基とを組み合わせた基（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のアルキルシクロアルキル基又はシクロアルキルアルキル基）、ベンジル基等のアラルキル基、アルキル基を有する芳香族炭化水素基（ｐ－メチルフェニル基、ｐ－ｔｅｒｔ－ブチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、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）、脂環式炭化水素基を有する芳香族炭化水素基（ｐ－シクロヘキシルフェニル基、ｐ－アダマンチルフェニル基等）、フェニルシクロヘキシル基等のアリール－シクロアルキル基等が挙げられる。
好ましくは、ｍａは０であり、ｎａは１である。
Ｒ^a1及びＲ^a2が互いに結合して非芳香族炭化水素環を形成する場合の－Ｃ（Ｒ^a1）（Ｒ^a2）（Ｒ^a3）としては、下記の環が挙げられる。非芳香族炭化水素環は、好ましくは炭素数３～１２である。＊は－Ｏ－との結合部位を表す。

Examples of alkyl groups for R ^a1 , R ^a2 and R ^a3 include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group and octyl group.
The alkenyl group for R ^a1 , R ^a2 and R ^a3 includes ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, A nonenyl group is mentioned.
The alicyclic hydrocarbon groups for R ^a1 , R ^a2 and R ^a3 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 bonding site). The alicyclic hydrocarbon groups of R ^a1 , R ^a2 and R ^a3 preferably have 3 to 16 carbon atoms.

Examples of aromatic hydrocarbon groups for R ^a1 , R ^a2 and R ^a3 include aryl groups such as phenyl, naphthyl, anthryl, biphenyl and phenanthryl groups.
Examples of the combined group include groups obtained by combining the above alkyl groups and alicyclic hydrocarbon groups (e.g., methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl a dimethyl group, an alkylcycloalkyl group such as a norbornylethyl group or a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p- cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like.
Preferably, ma is 0 and na is 1.
-C(R ^a1 )(R ^a2 )(R ^a3 ) when R ^a1 and R ^a2 combine to form a non-aromatic hydrocarbon ring include the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * represents a binding site with -O-.

Ｒ^ａ１’及びＲ^ａ２’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。
ｎａ’は、好ましくは０である。 Examples of hydrocarbon groups for R ^a1′ , R ^a2′ and R ^a3′ include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and groups formed by combining these groups.
Examples of the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and combined group are the same as the groups exemplified for R ^a1 , R ^a2 and R ^a3 .
When R ^a2′ and R ^a3′ are bonded to each other to form a heterocyclic ring together with the carbon atom to which they are bonded and X, —C(R ^a1′ )(R ^a2′ )—X—R ^a3′ is represented by the following ring. * represents the binding site.

At least one of R ^a1′ and R ^a2′ is preferably a hydrogen atom.
na' is preferably zero.

Group (1) includes the following groups.
A group in which R ^a1 , R ^a2 and R ^a3 in formula (1) are alkyl groups, ma=0 and na=1. The group is preferably a tert-butoxycarbonyl group.
In formula (1), R ^a1 and R ^a2 form an adamantyl group together with the carbon atoms to which they are attached, R ^a3 is an alkyl group, ma = 0 and na = 1. .
A group in which R ^a1 and R ^a2 are each independently an alkyl group, R ^a3 is an adamantyl group, ma=0 and na=1 in formula (1).
Specific examples of the group (1) include the following groups. * represents a binding site.

Specific examples of group (2) include the following groups. * represents a binding site.

Monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer having an acid labile group.

Among (meth)acrylic monomers having an acid-labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferred. When the resin (A2) having a structural unit derived from the monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

［式（ａ１－０）、式（ａ１－１）及び式（ａ１－２）中、
Ｌ^a01、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－との結合部位を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、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^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、炭素数６～１８の芳香族炭化水素基又はこれらを組み合わせた基を表す。
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２～８のアルケニル基、炭素数３～１８の脂環式炭化水素基、炭素数６～１８の芳香族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。］ As a structural unit derived from a (meth)acrylic monomer having a group (1), a structural unit represented by formula (a1-0) (hereinafter sometimes referred to as structural unit (a1-0)), formula ( a1-1) (hereinafter sometimes referred to as structural unit (a1-1)) or a structural unit represented by formula (a1-2) (hereinafter referred to as structural unit (a1-2) There is a case.) is mentioned. Preferably, at least one or two structural units selected from the group consisting of structural unit (a1-0), structural unit (a1-1) and structural unit (a1-2), more preferably structural unit It is at least one or two structural units selected from the group consisting of (a1-1) and structural unit (a1-2). These may be used alone or in combination of two or more.

[In formula (a1-0), formula (a1-1) and formula (a1-2),
L ^a01 , L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, k1 represents an integer of 1 to 7, * is represents the binding site with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom, a halogen atom or an optionally halogenated alkyl group having 1 to 6 carbon atoms.
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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or Represents a combined group.
R ^a6 and R ^a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. It represents a hydrocarbon group or a group formed by combining these groups.
m1 represents any integer from 0 to 14;
n1 represents an integer from 0 to 10;
n1' represents an integer of 0 to 3; ]

R ^a01 , R ^a4 and R ^a5 are preferably a hydrogen atom or a methyl group, more preferably a methyl group.
L ^a01 , 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 is 1.), more preferably an oxygen atom.
R ^a02 , R ^a03 , R ^a04 , R ^{a6 and} R ^a7 include alkyl groups, alkenyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and groups in which these groups are combined. The same groups as those mentioned for R ^a2 and R ^a3 can be mentioned.
The alkyl group for R ^a02 , R ^a03 and R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, still more preferably a methyl group.
The alkyl group for R ^a6 and R ^a7 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group or a t-butyl group, still more preferably an ethyl group or an isopropyl group. or a t-butyl group.
The alkenyl group for R ^a6 and R ^a7 is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, propenyl group, isopropenyl group or butenyl group.
The alicyclic hydrocarbon groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 preferably have 5 to 12 carbon atoms, more preferably 5 to 10 carbon atoms.
The aromatic hydrocarbon groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 preferably have 6 to 12 carbon atoms, more preferably 6 to 10 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.
It is preferable that the combined group of an alkyl group and an aromatic hydrocarbon group have a total carbon number of 18 or less.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably methyl group, ethyl group, phenyl group or naphthyl group.
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.
R ^a6 and R ^a7 are each independently preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group , ethyl, isopropyl, t-butyl, ethenyl, phenyl or naphthyl, more preferably ethyl, isopropyl, t-butyl, ethenyl or phenyl.
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 0 or 1.

As the structural unit (a1-0), for example, a structural unit represented by any one of formulas (a1-0-1) to (a1-0-18) and R ^a01 in the structural unit (a1-0) Structural units in which the corresponding methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group (an alkyl group having a halogen atom) or another alkyl group, and the formulas (a1-0-1) to (a1-0- 10), a structural unit represented by formula (a1-0-13) or formula (a1-0-14) is preferred.

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 (a1-1-7) and a methyl group corresponding to R ^a4 in structural unit (a1-1) is a hydrogen atom or a halogen atom. , a haloalkyl group or other alkyl group is preferred, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferred.

The structural unit (a1-2) corresponds to a structural unit represented by any one of formulas (a1-2-1) to (a1-2-14) and R ^a5 in the structural unit (a1-2). Structural units in which a methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group include formula (a1-2-2), formula (a1-2-5), formula (a1-2-6 ) and structural units represented by any one of formulas (a1-2-10) to (a1-2-14) are preferred.

When the resin (A2) contains the structural unit (a1-0), its content is 5 mol% or more, preferably 10 mol% or more, based on the total structural units of the resin (A2). Further, it is 80 mol % or less, preferably 75 mol % or less, and more preferably 70 mol % or less. Specifically, it is 5 to 80 mol %, preferably 5 to 75 mol %, more preferably 10 to 70 mol %.
When the resin (A2) contains the structural unit (a1-1) and/or the structural unit (a1-2), the total content of these is 10 mol% or more with respect to the total structural units of the resin (A2). preferably 15 mol % or more, more preferably 20 mol % or more. Also, it is 90 mol % or less, preferably 85 mol % or less, more preferably 80 mol % or less, even more preferably 75 mol % or less, and even more preferably 70 mol % or less. Specifically, it is 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 20 to 80 mol%, still more preferably 20 to 75 mol%, still more preferably 20 to 70 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２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、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^a30は、単結合又は＊－Ｘ^a31－（Ａ^a32－Ｘ^a32）_nc－を表し、＊は－Ｒ^a32が結合する炭素原子との結合部位を表す。
Ａ^a32は、炭素数１～６のアルカンジイル基を表す。
Ｘ^a31及びＸ^a32は、それぞれ独立に、－Ｏ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ｎｃは、０又は１を表す。
ｌａは、０～４のいずれかの整数を表す。ｌａが２以上のいずれかの整数である場合、複数のＲ^a33は互いに同一であっても異なっていてもよい。
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。］ Structural units having group (2) in structural unit (a1) include structural units represented by formula (a1-4) (hereinafter sometimes referred to as “structural unit (a1-4)”). .

[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 alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, and a carbon number It represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a30 represents a single bond or *-X ^a31 -(A ^a32 -X ^a32 ) _nc -, and * represents a bonding site with the carbon atom to which -R ^a32 is bonded.
A ^a32 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a31 and X ^a32 each independently represent -O-, -CO-O- or -O-CO-.
nc represents 0 or 1;
la represents any integer from 0 to 4; When la is any integer of 2 or more, the 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. ]

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 for R ^a32 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 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 perfluoro A hexyl group is mentioned.
R ^a32 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 the alkyl group for R ^a33 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-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, and even more preferably a methyl group.
Alkoxy groups for R ^a33 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy and tert-butoxy groups. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and still more preferably a methoxy group.
Alkoxyalkyl groups for R ^a33 include methoxymethyl, ethoxyethyl, propoxymethyl, isopropoxymethyl, butoxymethyl, sec-butoxymethyl and tert-butoxymethyl groups. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, even more preferably a methoxymethyl group.
The alkoxyalkoxy group for R ^a33 includes a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group and a tert-butoxymethoxy group. mentioned. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group.
The alkylcarbonyl group for R ^a33 includes an acetyl group, a propionyl group and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group.
The alkylcarbonyloxy group for R ^a33 includes an acetyloxy group, a propionyloxy group and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group.
R ^a33 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, a fluorine atom, an iodine atom, a hydroxy group, a methyl A group, methoxy group, ethoxy group, ethoxyethoxy group or ethoxymethoxy group is more preferable, and fluorine atom, iodine atom, hydroxy group, methyl group, methoxy group or ethoxyethoxy group is more preferable.

*-X ^a31 -(A ^a32 -X ^a32 ) _nc - includes *-O-, *-CO-O-, *-O-CO-, *-CO-O-A ^a32 -CO-O-, *-O-CO- ^Aa32 -O-, *-O- ^Aa32 -CO-O-, *-CO-O- ^Aa32 -O-CO-, *-O-CO- ^Aa32 -O-CO -, are included. Among them, *-CO-O-, *-CO-O-A ^a32 -CO-O- or *-O-A ^a32 -CO-O- is preferred.

Alkanediyl group for A ^a32 includes methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group and 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 and 2-methylbutane-1,4-diyl group.
A ^a32 is preferably a methylene group or an ethylene group.

A ^a30 is preferably a single bond, *—CO—O— or *—CO—O—A ^a32 —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.

芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニル基、フェナントリル基等のアリール基が挙げられる。
組み合わせた基としては、上述したアルキル基と脂環式炭化水素基とを組み合わせた基（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のアルキルシクロアルキル基又はシクロアルキルアルキル基）、ベンジル基等のアラルキル基、アルキル基を有する芳香族炭化水素基（ｐ－メチルフェニル基、ｐ－ｔｅｒｔ－ブチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、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）、脂環式炭化水素基を有する芳香族炭化水素基（ｐ－シクロヘキシルフェニル基、ｐ－アダマンチルフェニル基等）、フェニルシクロヘキシル基等のアリール－シクロアルキル基等が挙げられる。特に、Ｒ^a36としては、炭素数１～１８のアルキル基、炭素数３～１８の脂環式炭化水素基、炭素数６～１８の芳香族炭化水素基又はこれらを組み合わせることにより形成される基が挙げられる。 la is preferably 0, 1 or 2, more preferably 0 or 1, and still more preferably 0.
The hydrocarbon groups for R ^a34 , R ^a35 and R ^a36 include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and combinations thereof.
Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl groups.
The alicyclic hydrocarbon group 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 bonding site).

Aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups.
Examples of the combined group include groups obtained by combining the above alkyl groups and alicyclic hydrocarbon groups (e.g., methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl a dimethyl group, an alkylcycloalkyl group such as a norbornylethyl group or a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p- cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like. 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.

R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, 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 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.
--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.
—OC(R ^a34 )(R ^a35 )—OR ^a36 preferably bonds to the m-position or p-position of the benzene ring, more preferably to the p-position.

Examples of structural units (a1-4) include structural units derived from monomers described in JP-A-2010-204646. Preferably, structural units represented by formulas (a1-4-1) to (a1-4-24) and structural units in which the hydrogen atom corresponding to R ^a32 is replaced with a halogen atom, a haloalkyl group or an alkyl group and more preferably formula (a1-4-1) ~ formula (a1-4-5), formula (a1-4-10), formula (a1-4-13), formula (a1-4- 14), structural units represented by formula (a1-4-19), and formula (a1-4-20).

When the resin (A2) contains the structural unit (a1-4), the content thereof is preferably 3 to 80 mol%, preferably 5 to 75 mol%, based on the total of all structural units of the resin (A2). It is more preferably 7 to 70 mol %, even more preferably 7 to 65 mol %, even more preferably 10 to 60 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との結合部位を表す。
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。］ Structural units derived from (meth)acrylic monomers having group (2) include structural units represented by formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”). be done.

[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 binding site with L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent -O- or -S-.
s1 represents an integer of 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 (A2) contains the structural unit (a1-5), its content is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on the total structural units of the resin (A2). , more preferably 5 to 40 mol %, and even more preferably 5 to 30 mol %.

The structural unit (a1) also includes the following structural units.

When the resin (A2) contains structural units such as (a1-3-1) to (a1-3-7), the content is 10 to 95 with respect to the total structural units of the resin (A2). mol % is preferred, 15 to 90 mol % is more preferred, 20 to 85 mol % is even more preferred, 20 to 70 mol % is even more preferred, and 20 to 60 mol % is particularly preferred.

樹脂（Ａ２）が上記、（ａ１－６－１）～（ａ１－６－３）のような構造単位を含む場合、その含有率は、樹脂（Ａ２）の全構造単位に対して、１０～６０モル％が好ましく、１５～５５モル％がより好ましく、２０～５０モル％がさらに好ましく、２０～４５モル％がさらにより好ましく、２０～４０モル％が特に好ましい。 The structural unit (a1) also includes the following structural units.

When the resin (A2) contains structural units such as the above (a1-6-1) to (a1-6-3), the content is 10 to 10 to the total structural units of the resin (A2). 60 mol % is preferred, 15 to 55 mol % is more preferred, 20 to 50 mol % is even more preferred, 20 to 45 mol % is even more preferred, and 20 to 40 mol % is particularly preferred.

<Structural unit (s)>
Structural unit (s) is derived from a monomer having 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 containing 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) , a structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use a structural unit (a2-A) described later. 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.

［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いてもよい炭素数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２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、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部位を表す。
Ａ^a52は、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いてもよい。］ 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 alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, It represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51 -(A ^a52 -X ^a52 ) _nb -, and * represents a bonding site with the carbon atom to which -R ^a50 bonds.
A ^a52 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 and R ^a51 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 a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 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 perfluoro A hexyl group is mentioned.
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. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.
Alkoxy groups for R ^a51 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy and tert-butoxy groups. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and still more preferably a methoxy group.
Alkoxyalkyl groups for R ^a51 include methoxymethyl, ethoxyethyl, propoxymethyl, isopropoxymethyl, butoxymethyl, sec-butoxymethyl and tert-butoxymethyl groups. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, even more preferably a methoxymethyl group.
The alkoxyalkoxy group for R ^a51 includes a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group and a tert-butoxymethoxy group. mentioned. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group.
The alkylcarbonyl group for R ^a51 includes an acetyl group, a propionyl group and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group.
The alkylcarbonyloxy group for R ^a51 includes an acetyloxy group, a propionyloxy group and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group.
R ^a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, a fluorine atom, an iodine atom, a hydroxy group, a methyl A group, methoxy group, ethoxy group, ethoxyethoxy group or ethoxymethoxy group is more preferable, and fluorine atom, iodine atom, hydroxy group, methyl group, methoxy group or ethoxyethoxy group is more preferable.

*-X ^a51 -(A ^a52 -X ^a52 ) _nb - includes *-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- or *-OA ^a52 -CO-O- is preferred.

The alkanediyl group for A ^a52 includes methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, and 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 and 2-methylbutane-1,4-diyl group.
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 still more preferably 0.
At least one hydroxy group is preferably attached to the m-position or p-position of the benzene ring. When the phenyl group contains two or more hydroxy groups, the two hydroxy groups are preferably bonded to the m-position and p-position, respectively.

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 (a2-2-24) and formulas (a2-2-1) to (a2-2-24). ) in which the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. Structural unit (a2-A) includes structural units represented by formulas (a2-2-1) to (a2-2-4), structural units represented by formula (a2-2-6), and structural units represented by formula ( a2-2-8), structural units represented by formulas (a2-2-12) to (a2-2-18) and formulas (a2-2-1) to (a2- 2-4), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), and formulas (a2-2-12) to In the structural unit represented by formula (a2-2-18), it is preferably a structural unit in which the methyl group corresponding to R ^a50 in structural unit (a2-A) is replaced with a hydrogen atom. -3), structural unit represented by formula (a2-2-4), structural unit represented by formula (a2-2-8), formula (a2-2-12) to formula Structural unit represented by (a2-2-14), structural unit represented by formula (a2-2-18) and structural unit represented by formula (a2-2-3), formula (a2-2- 4), structural units represented by formula (a2-2-8), structural units represented by formulas (a2-2-12) to (a2-2-14), and formula ( a2-2-18), the structural unit is more 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, and the structural unit represented by the formula (a2-2- 3), a structural unit represented by formula (a2-2-4), a structural unit represented by formula (a2-2-8) and a structural unit represented by formula (a2-2-3) the structural unit represented by formula (a2-2-4), the structural unit represented by formula (a2-2-8), the methyl group corresponding to R ^a50 in structural unit (a2-A) is more preferably a structural unit in which is replaced with a hydrogen atom.

When the structural unit (a2-A) is contained in the resin (A2), the content of the structural unit (a2-A) is preferably 5 mol% or more, more preferably 10 mol%, based on the total structural units. It is mol % or more, more preferably 15 mol % or more, and still more preferably 20 mol % or more. Also, it is preferably 80 mol % or less, more preferably 70 mol % or less, and still more preferably 65 mol % or less. Specifically, it is preferably 5 to 80 mol %, more preferably 10 to 70 mol %, even more preferably 15 to 65 mol %, still more preferably 20 to 65 mol %.
The structural unit (a2-A) can be included in the resin (A2), for example, by polymerizing the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Further, the structural unit (a2-A) can be included in the resin (A2) 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－との結合部位を表す。
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 the formula (a2-1),
L ^a3 represents -O- or *-O-(CH ₂ ) _k2 -CO-O-,
k2 represents any integer from 1 to 7; * represents a bonding site 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) , and 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 structural units (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 the formula (a2-1-1) or (a2-1-3) are more preferable.

When the resin (A2) contains the structural unit (a2-1), the content thereof may be 1 mol % or more, preferably 2 mol % or more, based on the total structural units of the resin (A2). Also, it is 45 mol % or less, preferably 40 mol % or less, more preferably 35 mol % or less, still more preferably 20 mol % or less, and even more preferably 10 mol % or less. Specifically, it is 1 to 45 mol%, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, still more preferably 1 to 20 mol%, still more preferably It is 1 to 10 mol %.

<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)).

［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部位を表す。
Ｒ^ａ１８、Ｒ^ａ１９、Ｒ^ａ２０及びＲ^ａ２４は、それぞれ独立に、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。
Ｘ^ａ３は、－ＣＨ_２－又は酸素原子を表す。
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異なっていてもよい。］ 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 a bonding site with a carbonyl group.
R ^a18 , R ^a19 , R ^a20 and R ^a24 each independently represent a hydrogen atom, a halogen atom or an optionally halogenated alkyl group having 1 to 6 carbon atoms.
X ^a3 represents —CH ₂ — or an oxygen 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 ^a18 , R ^a19 , R ^a20 and R ^a24 include fluorine, chlorine, bromine and iodine atoms.
Examples of alkyl groups for R ^a18 , R ^a19 , R ^a20 and 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 an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.
The alkyl group having a halogen atom for R ^a18 , R ^a19 , R ^a20 and R ^a24 includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, and a perfluorotert -butyl group, perfluoropentyl group, perfluorohexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group and the like.

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.

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.

（式中、Ｒ^ａ２４、Ｌ^ａ７は、上記と同じ意味を表す。） 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 ^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 (A2) contains the structural unit (a3), the total content thereof may be 1 mol% or more, preferably 3 mol% or more, relative to the total structural units of the resin (A2). It is preferably 5 mol % or more, more preferably 10 mol % or more. Also, it is 70 mol % or less, preferably 65 mol % or less, and more preferably 60 mol % or less. Specifically, it is 1 to 70 mol %, preferably 3 to 65 mol %, more preferably 5 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 is preferably 1 mol % or more, more preferably 3 mol % or more, still more preferably 5 mol % or more. Also, it is preferably 60 mol % or less, more preferably 55 mol % or less, and still more preferably 50 mol % or less. Specifically, it is preferably 1 to 60 mol %, more preferably 3 to 55 mol %, even more preferably 5 to 50 mol %, and even more preferably 10 to 50 mol %.

［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のハロゲン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、鎖式飽和炭化水素基及び単環又は多環の脂環式飽和炭化水素基、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。 <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 carbon atoms and a halogen atom, and -CH ₂ - contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. ]
The saturated hydrocarbon group represented by R ⁴² includes chain saturated hydrocarbon groups, monocyclic or polycyclic saturated alicyclic hydrocarbon groups, and groups formed by combining these groups.

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以上の脂環式飽和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－脂環式飽和炭化水素基、－脂環式飽和炭化水素基－アルキル基、－アルカンジイル基－脂環式飽和炭化水素基－アルキル基等が挙げられる。 Chain saturated hydrocarbon groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group. is mentioned.
Examples of monocyclic or polycyclic saturated alicyclic hydrocarbon groups include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and other cycloalkyl groups; decahydronaphthyl, adamantyl, norbornyl and the following polycyclic alicyclic saturated hydrocarbon groups such as groups (* represents a bonding site).

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 saturated hydrocarbon groups, and -alkanediyl groups Examples include - alicyclic saturated hydrocarbon group, - alicyclic saturated hydrocarbon group - alkyl group, - alkanediyl group - alicyclic saturated hydrocarbon group - alkyl group, and the like.

［式（ａ４－０）中、
Ｒ⁵⁴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。
Ｒ⁶⁴は、水素原子又はフッ素原子を表す。］ The structural unit (a4) is preferably a structural unit having a fluorine atom, and a structural unit represented by formula (a4-0), a structural unit represented by formula (a4-1), and a structural unit represented by formula (a4 -4) is a structural unit.

[In the formula (a4-0),
^R54 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.
^R64 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 ⁵⁴ 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価の飽和炭化水素基を表す。
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。〕
＊は結合部位であり、右側の＊が－Ｏ－ＣＯ－Ｒ^a42との結合部位である。］ Structural units (a4) include structural units represented by formula (a4-1).

[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 saturated 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 a binding site, and * on the right side is a binding site with --O--CO--R ^a42 . ]

Examples of saturated hydrocarbon groups for R ^a42 include chain saturated hydrocarbon groups, monocyclic or polycyclic saturated alicyclic hydrocarbon groups, groups formed by combining these groups, and the like.

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以上の脂環式飽和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－脂環式飽和炭化水素基、－脂環式飽和炭化水素基－アルキル基、－アルカンジイル基－脂環式飽和炭化水素基－アルキル基等が挙げられる。 Chain saturated hydrocarbon groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group. etc.
Examples of monocyclic or polycyclic saturated alicyclic hydrocarbon groups include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and other cycloalkyl groups; decahydronaphthyl, adamantyl, norbornyl and the following polycyclic alicyclic saturated hydrocarbon groups such as groups (* represents a bonding site).

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 saturated hydrocarbon groups, and -alkanediyl groups Examples include - alicyclic saturated hydrocarbon group, - alicyclic saturated hydrocarbon group - alkyl group, - alkanediyl group - alicyclic saturated hydrocarbon group - alkyl group, and the like.

［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。
Ａ^a45は、ハロゲン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。
＊はＲ^a42との結合部位を表す。］
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の飽和炭化水素基を表す。 Examples of substituents possessed by R ^a42 include at least one selected from the group consisting of halogen atoms and groups represented by formulas (a-g3). 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--.
A ^a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
* represents the binding site with ^Ra42 . ]
However, in R ^a42 -X ^a43 -A ^a45 , when R ^a42 does not have a halogen atom, A ^a45 represents a C 1-17 saturated hydrocarbon group having at least one halogen atom.

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。 The saturated hydrocarbon group for A ^a45 includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl Alkyl groups such as groups;
Monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups ) 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 is preferably a saturated hydrocarbon group which may have 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.

［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価の飽和炭化水素基を表す。
Ｘ^a44は、＊＊－Ｏ－ＣＯ－又は＊＊－ＣＯ－Ｏ－を表す（＊＊はＡ^a46との結合部位を表す。）。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１～１７の飽和炭化水素基を表す。
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部位を表す。］ 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 saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents **-O-CO- or **-CO-O- (** represents a binding site with A ^a46 ).
A ^a47 represents a saturated 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 a bonding site with a carbonyl group. ]

The saturated hydrocarbon group of A ^a46 preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.
The saturated hydrocarbon group of A ^a47 preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, 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 a bonding site with a 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 and 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 formula (a-g1) include linear or branched alkanediyl groups and monocyclic or polycyclic divalent An alicyclic saturated hydrocarbon group, a divalent saturated hydrocarbon group formed by combining an alkanediyl group and a divalent alicyclic saturated hydrocarbon group, and the like are included. 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.

Among the groups represented by the formula (a-g1), examples of groups in which X ^a42 is -O-, -CO-, -CO-O- or -O-CO- include the following groups. In the following examples, * and ** each represent a binding site, and ** is the binding site for --O--CO--R ^a42 .

As the structural unit represented by formula (a4-1), the following structural units 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。］ Structural units (a4) include structural units represented by formula (a4-2) and structural units represented by formula (a4-3).

[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 C 1-6 alkanediyl group for L ⁴⁴ include the same groups as those exemplified for A ^a41 .
Examples of the saturated hydrocarbon group for R ^f6 include the same groups as those exemplified for R ⁴² .
The alkanediyl group for L ⁴⁴ is preferably an alkanediyl group having 2 to 4 carbon atoms, 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との結合部位を表す。）。
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 a binding site 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. ]

Examples of the alkanediyl group for L ⁵ include the same groups as those exemplified for the alkanediyl group for A ^a41 .

The divalent saturated hydrocarbon group which may have a fluorine atom in A ^f13 preferably has a divalent chain saturated hydrocarbon group which may have a fluorine atom and a fluorine atom is a divalent saturated alicyclic hydrocarbon group, more preferably a perfluoroalkanediyl group.
Examples of the divalent chain saturated hydrocarbon group which may have a fluorine atom include 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, perfluoroalkanediyl groups such as perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group;
The divalent saturated 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 group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group and perfluorooctyl group 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 saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, A divalent chain saturated hydrocarbon group having 2 to 3 carbon atoms is more preferred.
The saturated hydrocarbon group of A ^f14 is preferably a group containing a chain saturated hydrocarbon group having 3 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and a saturated chain hydrocarbon group having 3 to 10 carbon atoms. Groups containing a hydrocarbon group and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms are more preferred. Among them, A ^f14 is preferably a group containing an alicyclic saturated 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. ]

Examples of the saturated hydrocarbon group for R ^f22 include those similar to the saturated hydrocarbon group for R ^a42 . R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic saturated hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, and an alkyl group having 1 to 10 carbon atoms having a fluorine atom is preferably More preferred is an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

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 (A2) contains 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 (A2). ~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 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— . ]

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.

［式（Ｌ１－１）中、
Ｘ^x1は、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＬ^x1との結合部位を表す。）。
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。］ 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 formulas, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom.

[In the formula (L1-1),
X ^x1 represents *-O-CO- or *-CO-O- (* represents a binding site 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 aliphatic saturated 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 saturated aliphatic 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.

式（Ｌ１－２）で表される基としては、例えば、以下に示す２価の基が挙げられる。

式（Ｌ１－３）で表される基としては、例えば、以下に示す２価の基が挙げられる。

式（Ｌ１－４）で表される基としては、例えば、以下に示す２価の基が挙げられる。

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 (L1-1) 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.

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).

樹脂（Ａ２）が、構造単位（ａ５）を含む場合、その含有率は、樹脂（Ａ２）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。 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.

When the resin (A2) contains 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 (A2). ~15 mol% is more preferred.

<Structural unit (a6)>
Structural unit (a6) is a structural unit having a —SO ₂ — group, and preferably has a —SO ₂ — group in its side chain.
A structural unit having a —SO ₂ — group may have a linear structure having a —SO ₂ — group, or may have a branched structure having a —SO ₂ — group, It may have a cyclic structure (monocyclic and polycyclic structures) having a —SO ₂ — group. Structural units having a cyclic structure containing —SO ₂ — groups are preferred, and structural units having a cyclic structure (sultone ring) containing —SO ₂ —O— are more preferred.

The sultone ring includes rings represented by the following formulas (T ¹ -1), (T ¹ -2), (T ¹ -3) and (T ¹ -4). The binding site can be at any position. The sultone ring may be monocyclic, but preferably polycyclic. A polycyclic sultone ring means a bridged ring containing —SO ₂ —O— as an atomic group constituting the ring, and is represented by formulas (T ¹ -1) and (T ¹ -2). ring. The sultone ring may further contain a heteroatom in addition to —SO ₂ —O— as an atomic group constituting the ring, like the ring represented by formula (T ¹ -2). A heteroatom includes an oxygen atom, a sulfur atom or a nitrogen atom, preferably an oxygen atom.

The sultone ring may have a substituent, and examples of the substituent include a halogen atom, an alkyl group having 1 to 12 carbon atoms optionally having a hydroxy group, a halogen atom, a hydroxy group, a cyano group, and 1 carbon atom. alkoxy groups of up to 12 carbon atoms, aryl groups of 6 to 12 carbon atoms, aralkyl groups of 7 to 12 carbon atoms, glycidyloxy groups, alkoxycarbonyl groups of 2 to 12 carbon atoms and alkylcarbonyl groups of 2 to 4 carbon atoms, and the like. be done.

Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
Alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl and decyl groups, preferably alkyl groups having 1 to 6 carbon atoms, more preferably methyl groups. is.
The alkyl group having a halogen atom 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, a perfluorohexyl group, trichloromethyl group, tribromomethyl group and triiodomethyl group, preferably trifluoromethyl group.
Alkyl groups having a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a 2-hydroxyethyl group.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups.
Aryl groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumyl, mesityl, biphenyl, and phenanthryl groups. groups, 2,6-diethylphenyl groups and 2-methyl-6-ethylphenyl groups.
Aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl and naphthylethyl groups.
The alkoxycarbonyl group includes groups in which an alkoxy group and a carbonyl group such as a methoxycarbonyl group and an ethoxycarbonyl group are bonded, preferably an alkoxycarbonyl group having 6 or less carbon atoms, more preferably a methoxycarbonyl group. mentioned.
Alkylcarbonyl groups include acetyl, propionyl and butyryl groups.

［式（Ｔ１’）中、
Ｘ^１１は、酸素原子、硫黄原子又はメチレン基を表す。
Ｒ^４１は、ハロゲン原子もしくはヒドロキシ基を有していてもよい炭素数１～１２のアルキル基、ハロゲン原子、ヒドロキシ基、シアノ基、炭素数１～１２のアルコキシ基、炭素数６～１２のアリール基、炭素数７～１２のアラルキル基、グリシジルオキシ基、炭素数２～１２のアルコキシカルボニル基又は炭素数２～４のアルキルカルボニル基を表す。
ｍａは、０～９のいずれかの整数を表す。ｍａが２以上のとき、複数のＲ^４１は同一であっても異なってもよい。
結合部位は任意の位置である。］
Ｘ^１１は、好ましくは酸素原子又はメチレン基であり、より好ましくはメチレン基である。
Ｒ^４１としては、スルトン環の置換基と同様のものが挙げられ、ハロゲン原子又はヒドロキシ基を有していてもよい炭素数１～１２のアルキル基が好ましい。
ｍａは、好ましくは０又は１であり、より好ましくは０である。 A sultone ring having no substituent is preferred from the viewpoint of facilitating the production of a monomer leading to the structural unit (a6).
As the sultone ring, a ring represented by the following formula (T1') is preferable.

[in the formula (T1′),
X ¹¹ represents an oxygen atom, a sulfur atom or a methylene group.
R ⁴¹ is an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. aralkyl group having 7 to 12 carbon atoms, glycidyloxy group, alkoxycarbonyl group having 2 to 12 carbon atoms or alkylcarbonyl group having 2 to 4 carbon atoms.
ma represents any integer from 0 to 9; When ma is 2 or more, multiple R ⁴¹ may be the same or different.
The binding site can be any position. ]
X ¹¹ is preferably an oxygen atom or a methylene group, more preferably a methylene group.
As R ⁴¹ , the same substituents as those for the sultone ring can be mentioned, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferred.
ma is preferably 0 or 1, more preferably 0.

The ring represented by formula (T1') includes the following rings. The binding site can be any position. Among them, the binding site is preferably at the 1st or 3rd position.

A structural unit having a —SO ₂ — group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include vinyl group, acryloyl group, methacryloyl group, acryloyloxy group, methacryloyloxy group, acryloylamino group, methacryloylamino group, acryloylthio group and methacryloylthio group.
Among them, the monomer leading to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer.

［式（ａ６－０）中、
Ｒ^ｘ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。
Ａ^ｘｘは、酸素原子、－Ｎ（Ｒ^ｃ）－又は硫黄原子を表す。
Ａ^ｘ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－、－ＣＯ－又は－Ｎ（Ｒ^ｄ）－に置き換わっていてもよい。
Ｘ^１１、Ｒ^４１及びｍａは、上記と同じ意味を表す。
Ｒ^ｃ及びＲ^ｄは、互いに独立に、水素原子又は炭素数１～６のアルキル基を表す。］ Structural unit (a6) is preferably a structural unit represented by formula (a6-0).

[In the formula (a6-0),
R ^x represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ^xx represents an oxygen atom, -N(R ^c )- or a sulfur atom.
A ^x 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 is —O—, —CO— or —N(R ^d )- may be substituted.
X ¹¹ , R ⁴¹ and ma have the same meanings as above.
R ^c and R ^d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. ]

Halogen atoms for R ^x include fluorine, chlorine, bromine and iodine atoms.
The alkyl group for R ^x includes, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group and n-hexyl group. and preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.
The alkyl group having a halogen atom for R ^x includes, for example, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. , perfluorohexyl group, trichloromethyl group, tribromomethyl group and triiodomethyl group.
R ^x 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.

The divalent saturated hydrocarbon group for A ^x includes a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic bivalent alicyclic saturated hydrocarbon group. A combination of two or more of the groups may also be used.
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, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-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- a branched alkanediyl group such as a 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 bivalent 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.
The bonding position of ^Ax to the sultone ring can be any position, but the 1-position is preferred.

Structural units (a6-0) include the following structural units.

Among them, structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8) and formula (a6-12) are preferred, and structural units represented by formulas (a6-1), (a6-2), (a6-7) and (a6-8) are more preferred.
When the resin (A2) contains the structural unit (a6), its content is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, based on the total structural units of the resin (A2). ~30 mol% is more preferred.

<Structural unit (II)>
The resin (A2) may further contain a structural unit (hereinafter sometimes referred to as "structural unit (II)") that decomposes to generate an acid upon exposure. Specific examples of the structural unit (II) include structural units described in JP-A-2016-79235. A structural unit having a group and an organic anion is 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。］ 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 which may have a halogen atom represented by R ^III3 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 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.
The perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted in A ^x1 includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, and a perfluorotert -butyl group, perfluoropentyl group, perfluorohexyl group and the like.

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 , a pentane-1,4-diyl group, a branched alkanediyl group such as a 2-methylbutane-1,4-diyl group;
Divalent monocyclic rings such as cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group and cyclooctane-1,5-diyl group a saturated alicyclic hydrocarbon group;
Bivalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group and adamantane-2,6-diyl group etc.

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 formula below, * and ** represent binding sites, and * represents a binding site with ^Ax1 .

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.

Organic cations represented by ZA ⁺ include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations and organic phosphonium cations. 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) described below (hereinafter, may be referred to as "cation (b2-1)" or the like depending on the formula number. ).

The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A).
[In the formula (II-2-A),
R ^III3 , X ^III3 and ZA ⁺ have the same meanings as above.
z represents an 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 may be the same or different may be
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 later. .

［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 the 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 the 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; ]

Structural units represented by formula (II-2-A′) include, for example, the following structural units, a group corresponding to a methyl group in R ^III3 is a hydrogen atom, a halogen atom (e.g., a fluorine atom) or a halogen atom Structural units and structural units described in International Publication No. 2012/050015 substituted with an alkyl group having 1 to 6 carbon atoms (eg, trifluoromethyl group, etc.) which may have. 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いてもよい炭素数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。
アルキル基及び脂環式炭化水素基は、上記と同様のものが挙げられる。
芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニル基、フェナントリル基等のアリール基が挙げられる。
組み合わせた基としては、上述したアルキル基と脂環式炭化水素基とを組み合わせた基、ベンジル基等のアラルキル基、アルキル基を有する芳香族炭化水素基（ｐ－メチルフェニル基、ｐ－ｔｅｒｔ－ブチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、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）、脂環式炭化水素基を有する芳香族炭化水素基（ｐ－シクロヘキシルフェニル基、ｐ－アダマンチルフェニル基等）、フェニルシクロヘキシル基等のアリール－シクロアルキル基等が挙げられる。
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.
Examples of the alkyl group and the alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups.
Examples of the combined group include a group obtained by combining an alkyl group and an alicyclic hydrocarbon group described above, an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert- butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having alicyclic hydrocarbon groups ( p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like.
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 .

The structural unit containing a cation in formula (II-1-1) includes structural units represented by the following: a group corresponding to a methyl group in R ^II4 is a hydrogen atom, a halogen atom (e.g., a fluorine atom) or Structural units substituted with alkyl groups having 1 to 6 carbon atoms which may have a halogen atom (eg, trifluoromethyl group, etc.).

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 examples of the sulfonate anion include the same anions contained in the salt represented by formula (B1) described below.

スルホニルメチドアニオンとしては、以下のものが挙げられる。

カルボン酸アニオンとしては、以下のものが挙げられる。

The 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 (A2) 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 (A2), and more It is preferably 2 to 15 mol %, more preferably 3 to 10 mol %.

Resin (A2) is preferably a resin composed of structural unit (a1) and structural unit (s), ie, a copolymer of monomer (a1) and monomer (s).
Structural unit (a1) is preferably a group consisting of structural unit (a1-0), structural unit (a1-1) and structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group) is at least one selected from, more preferably at least two, still more preferably at least two selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2).
Structural unit (s) is preferably at least one selected from the group consisting of structural unit (a2) and structural unit (a3). The structural unit (a2) may contain the structural unit (III) described above. Structural unit (a2) is preferably a structural unit represented by formula (a2-1) or a structural unit represented by formula (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 (A2) 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 (A2) can be adjusted by adjusting the amount of monomer used for polymerization.
The weight average molecular weight of the resin (A2) 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 is 15,000 or less). As used herein, the weight average molecular weight is a value obtained by gel permeation chromatography under the conditions described in Examples.

The content ratio (mass ratio) of the resin (A1) and the resin (A2) in the solid component of the resist composition of the present invention is, for example, 0.01:10 to 5:10, preferably 0.05:10 to 3: 10, more preferably 0.1:10 to 2:10, more preferably 0.2:10 to 1:10.

<Resins other than resins (A1) and (A2)>
The resist composition of the present invention contains resins other than the resins (A1) and (A2) described above, such as structural units derived from acid-stable monomers and structural units derived from known monomers used in the art. may contain a resin having at least one kind of
For example, a resin containing the structural unit (a4) or the structural unit (a5) (hereinafter sometimes referred to as resin (X)).
As the resin (X), among others, a resin containing the structural unit (a4) is preferable, and examples include a resin consisting only of the structural unit (a4) or a resin containing the structural unit (a4) and the structural unit (a5). Structural units that the resin (X) may further include structural units (a2), structural units (a3), and structural units derived from other known monomers.
When the resin (X) contains the structural unit (a4), the content of the structural unit (a4) in the resin (X) may be 20 mol% or more with respect to the total of all structural units in the resin (X). 30 mol % or more is preferable, 40 mol % or more is more preferable, and 45 mol % or more is even more preferable. Further, it is 100 mol % or less, preferably 80 mol % or less, more preferably 70 mol % or less, still more preferably 60 mol % or less, and even more preferably 55 mol % or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, still more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. When the resin (X) contains the structural unit (a5), the content of the structural unit (a5) may be 20 mol% or more, such as 30 mol% or more, based on the total of all structural units of the resin (X). is preferred, 40 mol % or more is more preferred, and 45 mol % or more is even more preferred. Further, it is 100 mol % or less, preferably 80 mol % or less, more preferably 70 mol % or less, still more preferably 60 mol % or less, and even more preferably 55 mol % or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, still more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. Further, when the resin (X) contains the structural unit (a4) and the structural unit (a5), the total content of the structural unit (a4) and the structural unit (a5) is the total of all structural units of the resin (X). On the other hand, it is 40 mol % or more, preferably 60 mol % or more, more preferably 70 mol % or more, and even more preferably 80 mol % or more. Moreover, 100 mol% or less is mentioned. Specifically, it is 40 to 100 mol %, preferably 60 to 100 mol %, more preferably 70 to 100 mol %, even more preferably 80 to 100 mol %.
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 polymer 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 weight of resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight-average molecular weight of resin (X) is the same as for resin (A1) and resin (A2).
When the resist composition contains the resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 60 parts by mass, relative to the total 100 parts by mass of the resin (A1) and the resin (A2). It is 50 parts by mass, more preferably 1 to 40 parts by mass, even more preferably 1 to 30 parts by mass, and even more preferably 1 to 8 parts by mass.

When the resist composition of the present invention contains resins other than resins (A1), (A2), and resin (X), the content of these resins (A1) and resin ( It is generally 0.1 to 50% by mass, preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass, relative to the total amount of A2).

The total content of all resins in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, relative to the solid content of the resist composition. preferable. Further, the total content of the resin (A1) and the resin (A2) in the resist composition is preferably 80% by mass or more and 99% by mass or less, based on the solid content of the resist composition, and 90% by mass or more and 99% by mass. % or less is more preferable. 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、水素原子、フッ素原子、炭素数１～６のアルキル基又は炭素数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３～２４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－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ１^＋は、有機カチオンを表す。］ The acid generator (B) is preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)").

[In formula (B1),
Q ^b1 and Q ^b2 each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O— or —CO—, and the saturated A hydrogen atom contained in the 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 24 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S-, -SO ₂ - or -CO-.
Z1 ⁺ represents an organic cation. ]

Examples of alkyl groups represented by Q ^b1 and Q ^b2 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group.
The perfluoroalkyl groups represented by Q ^b1 and Q ^b2 include 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 perfluorohexyl group and the like can be mentioned.
The acid generator (B) is preferably a fluorine-containing acid generator, and one of Q ^b1 and Q ^b2 is preferably a fluorine atom or a perfluoroalkyl group, each independently a fluorine atom or a trifluoroalkyl group. A fluoromethyl group is more preferred, and both are more preferably fluorine atoms.

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 bivalent 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) The group represented by any one of is mentioned. In addition, in the groups represented by formulas (b1-1) to (b1-3) and the groups represented by formulas (b1-4) to (b1-11) which are specific examples thereof, * and * * represents the binding site and * represents the binding site with -Y.

［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, a methylene group, -CH(CF ₃ )- or -C(CF ₃ ) ₂ -.
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, hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms, more preferably methylene groups, —CH(CF ₃ )—, —C(CF ₃ ) ₂ —.
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—.

［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い。
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い。
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い。
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。］
Ｌ^ｂ８は、好ましくは炭素数１～４の２価の飽和炭化水素基である。
Ｌ^ｂ９は、好ましくは炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１０は、好ましくは単結合又は炭素数１～１９の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１１は、好ましくは炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１２は、好ましくは単結合又は炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１３は、好ましくは炭素数１～１２の２価の飽和炭化水素基である。
Ｌ^ｂ１４は、好ましくは単結合又は炭素数１～６の２価の飽和炭化水素基である。
Ｌ^ｂ１５は、好ましくは単結合又は炭素数１～１８の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１６は、好ましくは炭素数１～１２の２価の飽和炭化水素基である。
Ｌ^ｂ１７は、好ましくは炭素数１～６の２価の飽和炭化水素基である。
Ｌ^ｂ１８は、好ましくは単結合又は炭素数１～１７の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１～４の２価の飽和炭化水素基である。 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.
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, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.
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, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced with —O— or —CO— good too.
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, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.
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 the 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.

Ｙで表される脂環式炭化水素基としては、好ましくは式（Ｙ１）～式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）～式（Ｙ４３）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（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）、式（Ｙ４０）、式（Ｙ４２）又は式（Ｙ４３）で表される基であり、さらに好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）、式（Ｙ４０）、式（Ｙ４２）又は式（Ｙ４３）で表される基である。
Ｙで表される脂環式炭化水素基が式（Ｙ２８）～式（Ｙ３５）、式（Ｙ３９）、式（Ｙ４０）、式（Ｙ４２）、式（Ｙ４３）等の酸素原子を有する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。 The alicyclic hydrocarbon group in which —CH ₂ — contained in the alicyclic hydrocarbon group represented by Y is not replaced with —O—, —S—, —SO ₂ — or —CO— is represented by the formula ( Y1) to formula (Y11) and groups represented by formulas (Y36) to (Y38).
When —CH ₂ — contained in the alicyclic hydrocarbon group represented by Y is replaced with —O—, —S—, —SO ₂ — or —CO—, the number may be 1, or 2 or more. It's okay. Such groups include groups represented by formulas (Y12) to (Y35) and formulas (Y39) to (Y43). —O— or —CO— in groups represented by formulas (Y12) to (Y35) and formulas (Y39) to (Y43) may be replaced with —S— or —SO ₂ —. * represents the binding site with L ^b1 .

The alicyclic hydrocarbon group represented by Y is preferably represented by formulas (Y1) to (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), and formula (Y39). to a group represented by any one of formula (Y43), more preferably formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y26), formula (Y27), formula (Y30), a group represented by formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43), more preferably formula (Y11), formula (Y15) or formula (Y20), a group represented by formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43) .
The alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom such as formulas (Y28) to (Y35), formula (Y39), formula (Y40), formula (Y42), and formula (Y43). In some cases it is preferred that the alkanediyl group between the two oxygen atoms 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, -( CH ₂ ) _ja —CO—O—R ^b1 group or —(CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, ja represents an integer of 0 to 4. The alkyl group and the alicyclic carbonization —CH ₂ — contained in the hydrogen group may be replaced with —O—, —SO ₂ — or —CO—, and may be included in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group. may be replaced with a hydroxy group or a fluorine atom.) and the like.
Substituents for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, and an alkyl group having 1 to 16 carbon atoms optionally substituted by a hydroxy group (-CH ₂ - may be replaced with -O- or -CO-.), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aromatic hydrocarbon group having 7 to 21 carbon atoms, aralkyl group, glycidyloxy group, —(CH ₂ ) _ja —CO—O—R ^b1 group or —(CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is C 1-16 represents an alkyl group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, ja represents an integer of 0 to 4; —CH ₂ — contained in the alkyl group and the alicyclic hydrocarbon group may be replaced with —O—, —SO ₂ — or —CO—, and the alkyl group and the alicyclic hydrocarbon group and a hydrogen atom contained in the aromatic hydrocarbon group may be replaced with a hydroxy group or a fluorine atom.) 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. The alicyclic hydrocarbon group may have a chain hydrocarbon group, such as a methylcyclohexyl group and a dimethylcyclohexyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3-12, more preferably 3-10.
Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group. , mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, and the like, and an aromatic having an alicyclic hydrocarbon group. The hydrocarbon group includes p-cyclohexylphenyl group, p-adamantylphenyl group and the like. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6-14, more preferably 6-10.
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. The number of carbon atoms in the alkyl group is preferably 1-12, more preferably 1-6, still more preferably 1-4.
Alkyl groups substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl and naphthylethyl groups.
The groups in which —CH ₂ — contained in the alkyl group is replaced with —O—, —SO ₂ —, —CO—, etc. include an alkoxy group, an alkylsulfonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or Groups in which these are combined, and the like are included.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups. The alkoxy group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 4 carbon atoms.
Examples of alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl and butoxycarbonyl groups. The alkoxycarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
Examples of alkylcarbonyl groups include acetyl group, propionyl group and butyryl group. The number of carbon atoms in the alkylcarbonyl group is preferably 2-12, more preferably 2-6, still more preferably 2-4.
Examples of alkylsulfonyl groups include methylsulfonyl, ethylsulfonyl, and propylsulfonyl groups. The number of carbon atoms in the alkylsulfonyl group is preferably 1-12, more preferably 1-6, still more preferably 1-4.
The alkylcarbonyloxy group includes, for example, an acetyloxy group, a propionyloxy group, a butyryloxy group and the like. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2-12, more preferably 2-6, still more preferably 2-4.
Examples of the combined group include, for example, a group in which an alkoxy group and an alkyl group are combined, a group in which an alkoxy group and an alkoxy group are combined, a group in which an alkoxy group and an alkylcarbonyl group are combined, an alkoxy group and an alkylcarbonyloxy group, and and the like.
Examples of groups in which an alkoxy group and an alkyl group are combined include alkoxyalkyl groups such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group and an ethoxymethyl group. The alkoxyalkyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
Groups in which an alkoxy group and an alkoxy group are combined include alkoxyalkoxy groups such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, and an ethoxyethoxy group. The alkoxyalkoxy group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
Groups in which an alkoxy group and an alkylcarbonyl group are combined include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group and an ethoxypropionyl group. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3-13, more preferably 3-7, still more preferably 3-5.
Groups in which an alkoxy group and an alkylcarbonyloxy group are combined include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, and an ethoxypropionyloxy group. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3-13, more preferably 3-7, still more preferably 3-5.
Groups in which —CH ₂ — contained in the alicyclic hydrocarbon group is replaced with —O—, —SO ₂ —, or —CO— include formulas (Y12) to (Y35), formulas (Y39) to A group represented by (Y43) and the like can be mentioned.

Y is preferably an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, more preferably an optionally substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms A hydrocarbon group, more preferably an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, still more preferably an optionally substituted adamantyl group or a substituted is a norbornyl group optionally having a group, and —CH ₂ — constituting the alicyclic hydrocarbon group, adamantyl group or norbornyl group is —O—, —S—, —SO ₂ — or —CO— may be replaced by Specifically, the following are mentioned.

Among them, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, a norbornanelactone group or represented by formula (Y42), formula (Y100) to formula (Y114), formula (Y134) to formula (Y139). is a group, particularly preferably a hydroxyadamantyl group, an oxoadamantyl group, a group containing these or represented by formula (Y42), formula (Y100) to formula (Y114), formula (Y134) to formula (Y139) is the base.

Examples of the anion in the salt represented by formula (B1) include anions represented by formulas (B1-A-1) to (B1-A-65) [hereinafter referred to as "anion (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), represented by any of formulas (B1-A-36) to (B1-A-40), formulas (B1-A-47) to (B1-A-65) Anions are more preferred.

ここでＲ^ｉ２～Ｒ^ｉ７は、互いに独立に、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の鎖式炭化水素基、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^Ａ４１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。
式（Ｂ１）で表される塩におけるアニオンとしては、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, a chain 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 ^A41 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 anion in the salt represented by formula (B1) include the anions described in JP-A-2010-204646.

Anions in the salt represented by formula (B1) are preferably anions represented by formulas (B1a-1) to (B1a-43).

Among them, formula (B1a-1) ~ formula (B1a-4), formula (B1a-7) ~ formula (B1a-11), formula (B1a-14) ~ formula (B1a-30) and formula (B1a-35 ) to Formula (B1a-41) are preferred.
The sulfonylimide anions and sulfonylmethide anions are the same as those described above.

［式（ｂ２－１）～式（ｂ２－４）中、
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、炭素数１～１８の脂肪族炭化水素基、炭素数１～１２のフッ化アルキル基又は炭素数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、ハロゲン原子、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基、炭素数１～１２のフッ化アルキル基又は炭素数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、該鎖式炭化水素基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、ハロゲン原子、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基、炭素数１～１２のフッ化アルキル基又は炭素数１～１２のアルコキシ基を表す。
Ｒ^b13とＲ^b14とは、互いに結合してそれらが結合するベンゼン環と一緒になって硫黄原子を含む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。
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。］
ｕ２が０のとき、ｏ２、ｐ２、ｑ２及びｒ２のうちいずれか１つは１以上であり、Ｒ^b13～Ｒ^b1６のうち少なくとも１つはハロゲン原子であることが好ましく、ｕ２が１のとき、ｏ２、ｐ２、ｓ２、ｔ２、ｑ２及びｒ２のうちいずれか１つは１以上であり、Ｒ^b13～Ｒ^b18のうち少なくとも１つはハロゲン原子であることが好ましい。
さらに、ｕ２が０のとき、ｒ２は１以上であることが好ましく、１であることがさらに好ましい。また、ｕ２が０、かつ、ｒ２が１以上のとき、Ｒ^ｂ１６がハロゲン原子であることが好ましい。 Organic cations of Z1 ⁺ include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations and organic phosphonium cations. 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.

[In the 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 the hydrogen atom contained in the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or a carbon It may be substituted with 1 to 12 alkoxy groups.
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 represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl 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 the chain hydrocarbon group The hydrogen atoms contained may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atoms contained in the aromatic hydrocarbon groups are alkoxy groups having 1 to 12 carbon atoms or 1 carbon atoms. It may be optionally 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 represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. .
R ^b13 and R ^b14 may be bonded to each other to form a sulfur atom-containing ring together with the benzene ring to which they are bonded, and —CH ₂ — contained in the ring may be —O—, -S- or -CO- may be substituted.
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. ]
When u2 is 0, any one of o2, p2, q2 and r2 is 1 or more, and at least one of R ^b13 to R ^b16 is preferably a halogen atom; Any one of o2, p2, s2, t2, q2 and r2 is 1 or more, and at least one of R ^b13 to R ^b18 is preferably a halogen atom.
Furthermore, when u2 is 0, r2 is preferably 1 or more, more preferably 1. Further, when u2 is 0 and r2 is 1 or more, ^Rb16 is preferably a halogen atom.

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。 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.

A fluorinated alkyl group means an alkyl group having 1 to 12 carbon atoms and having a fluorine atom, and includes a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group and the like. The number of carbon atoms in the fluorinated alkyl group is preferably 1-9, more preferably 1-6, still more preferably 1-4.

The aromatic hydrocarbon group includes aryl groups such as phenyl group, biphenyl group, naphthyl group, phenanthryl group and the like. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and aromatic hydrocarbon groups having chain hydrocarbon groups (tolyl, xylyl, cumenyl, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and an aromatic hydrocarbon group having an alicyclic hydrocarbon group ( p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) and the like.
In addition, when the aromatic hydrocarbon group has 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 is 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 to each other and 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. * represents a binding site.

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 thereof 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.

カチオン（ｂ２－２）としては、以下のカチオンが挙げられる。

カチオン（ｂ２－３）としては、以下のカチオンが挙げられる。

カチオン（ｂ２－４）としては、以下のカチオンが挙げられる。

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 aforementioned anions and the aforementioned organic cations, and these can be combined arbitrarily. As the acid generator (B), preferably formulas (B1a-1) to (B1a-4), formulas (B1a-7) to (B1a-11), formulas (B1a-14) to (B1a- 30) and an anion represented by any one of formulas (B1a-35) to (B1a-41), and cation (b2-1), cation (b2-2), cation (b2-3) or cation (b2 -4).

As the acid generator (B), those represented by formulas (B1-1) to (B1-60) are preferred. Among them, those containing an arylsulfonium cation are preferable, and formulas (B1-1) to (B1-3), formulas (B1-5) to (B1-7), formulas (B1-11) to (B1-14) ), formulas (B1-20) to (B1-26), formulas (B1-29), and formulas (B1-31) to (B1-60) are particularly preferred.

In the resist composition of the present invention, the content of the acid generator is preferably 0.1% by mass or more and 99.9% by mass or less, more preferably 1% by mass, based on the solid content of the resist composition. 45 mass % or less, more preferably 1 mass % or more and 40 mass % or less, and still more preferably 3 mass % or more and 40 mass % or less. Further, with respect to 100 parts by mass of the resin (A2), preferably 1 part by mass or more and 55 parts by mass or less, more preferably 3 parts by mass or more and 50 parts by mass or less, and still more preferably 10 parts by mass or more and 45 parts by mass or less. be.

<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 salts that generate acids weaker in acidity than acids generated from basic nitrogen-containing organic compounds and acid generators. When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15% by mass, based on the solid content of the resist composition. It is more preferably about 01 to 12% by mass, even more preferably about 0.1 to 10% by mass, and even more preferably about 0.1 to 8% by mass.
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, Diisopropylaniline is 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 that is weaker than the acid generated from the acid generator 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 is a salt having an acid dissociation constant of -3<pKa, preferably -1<pKa<7. and more preferably a salt with 0<pKa<5.
Examples of the salt that generates an acid weaker in acidity than the acid generated from the acid generator include salts represented by the following formula, and salts represented by the formula (D) described in JP-A-2015-147926 (hereinafter referred to as Sometimes referred to as "weak acid inner salt (D)"), and JP 2012-229206, JP 2012-6908, JP 2012-72109, JP 2011-39502 and patent Examples thereof include salts described in JP-A-2011-191745. It is preferably a salt that generates a carboxylic acid having a weaker acidity than the acid generated from the acid generator (salt having a carboxylic acid anion), more preferably a weak acid inner salt (D), and still more preferably , among the weak acid inner salts (D), is a diphenyliodonium salt containing a phenyl group substituted with a carboxylate anion.

［式（Ｄ）中、
Ｒ^D1及びＲ^D2は、それぞれ独立に、炭素数１～１２の炭化水素基、炭素数１～６のアルコキシ基、炭素数２～７のアシル基、炭素数２～７のアシルオキシ基、炭素数２～７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、それぞれ独立に、０～４のいずれかの整数を表し、ｍ’が２以上の場合、複数のＲ^D1は同一であっても異なってもよく、ｎ’が２以上の場合、複数のＲ^D2は同一であっても異なってもよい。］
Ｒ^D1及びＲ^D2の炭化水素基としては、鎖式炭化水素基、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。
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、イソブチル基、ｔｅｒｔ－ブチル基、ペンチル基、ヘキシル基、ノニル基等のアルキル基が挙げられる。
脂環式炭化水素基としては、単環式及び多環式のいずれでもよく、飽和及び不飽和のいずれでもよい。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、シクロノニル基、シクロドデシル基等のシクロアルキル基、ノルボニル基、アダマンチル基等が挙げられる。
芳香族炭化水素基としては、フェニル基、１－ナフチル基、２－ナフチル基、２－メチルフェニル基、３－メチルフェニル基、４－メチルフェニル基、４－エチルフェニル基、４－プロピルフェニル基、４－イソプロピルフェニル基、４－ブチルフェニル基、４－ｔ－ブチルフェニル基、４－ヘキシルフェニル基、４－シクロヘキシルフェニル基、アントリル基、ｐ－アダマンチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、ビフェニル基、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等が挙げられる。
これらを組み合わせることにより形成される基としては、アルキル－シクロアルキル基、シクロアルキル－アルキル基、アラルキル基（例えば、フェニルメチル基、１－フェニルエチル基、２－フェニルエチル基、１－フェニル－１－プロピル基、１－フェニル－２－プロピル基、２－フェニル－２－プロピル基、３－フェニル－１－プロピル基、４－フェニル－１－ブチル基、５－フェニル－１－ペンチル基、６－フェニル－１－ヘキシル基等）等が挙げられる。
アルコキシ基としては、メトキシ基、エトキシ基等が挙げられる。
アシル基としては、アセチル基、プロパノイル基、ベンゾイル基、シクロヘキサンカルボニル基等が挙げられる。
アシルオキシ基としては、上記アシル基にオキシ基（－Ｏ－）が結合した基等が挙げられる。
アルコキシカルボニル基としては、上記アルコキシ基にカルボニル基（－ＣＯ－）が結合した基等が挙げられる。
ハロゲン原子としては、フッ素原子、塩素原子、臭素原子等が挙げられる。
Ｒ^D1及びＲ^D2は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１０のシクロアルキル基、炭素数１～６のアルコキシ基、炭素数２～４のアシル基、炭素数２～４のアシルオキシ基、炭素数２～４のアルコキシカルボニル基、ニトロ基又はハロゲン原子が好ましい。
ｍ’及びｎ’は、それぞれ独立に、０～２のいずれかの整数であることが好ましく、０であることがより好ましい。ｍ’が２以上の場合、複数のＲ^D1は同一であっても異なってもよく、ｎ’が２以上の場合、複数のＲ^D2は同一であっても異なってもよい。
より具体的には、以下の塩が挙げられる。

As the weak acid inner salt (D), diphenyliodonium having an iodonium cation to which two phenyl groups are bonded and a carboxylate anion substituted by at least one of the two phenyl groups bonded to the iodonium cation. Salts are preferred, and examples thereof include salts represented by the following formulas.

[In the formula (D),
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, and a carbon number represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms;
m' and n' each independently represent an integer of 0 to 4, and when m' is 2 or more, the plurality of R ^D1 may be the same or different, and n' is 2 or more , the plurality of R ^D2 may be the same or different. ]
Examples of hydrocarbon groups for R ^D1 and R ^D2 include chain hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, groups formed by combining these groups, and the like.
Chain hydrocarbon groups include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group and nonyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be saturated or unsaturated. cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group and cyclododecyl group; norbornyl group; adamantyl group;
Aromatic hydrocarbon groups include phenyl, 1-naphthyl, 2-naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl and 4-propylphenyl groups. , 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group , mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and the like.
Groups formed by combining these groups include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, aralkyl groups (e.g., phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1 -propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6 -phenyl-1-hexyl group, etc.).
The alkoxy group includes a methoxy group, an ethoxy group, and the like.
The acyl group includes acetyl group, propanoyl group, benzoyl group, cyclohexanecarbonyl group and the like.
Examples of the acyloxy group include groups in which an oxy group (--O--) is bonded to the above acyl group.
Examples of the alkoxycarbonyl group include groups in which a carbonyl group (--CO--) is bonded to the above alkoxy group.
A fluorine atom, a chlorine atom, a bromine atom etc. are mentioned as a halogen atom.
R ^D1 and R ^D2 each independently represent an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, and an acyl group having 2 to 4 carbon atoms. Acyloxy groups having 2 to 4 carbon atoms, alkoxycarbonyl groups having 2 to 4 carbon atoms, nitro groups or halogen atoms are preferred.
Each of m' and n' is preferably an integer of 0 to 2, more preferably 0. When m' is 2 or more, multiple R ^D1 may be the same or different, and when n' is 2 or more, multiple R ^D2 may be the same or different.
More specific examples include the following salts.

<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 a resin (A1), a resin (A2) and an acid generator (B), and, if necessary, a resin other than the resin (A1) and the resin (A2), a solvent (E), It can be prepared by mixing a quencher (C) 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 and the solubility of the resin 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 the substrate include an inorganic substrate such as a silicon wafer and an organic substrate having a resist film or the like formed on the surface thereof. 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, extreme ultraviolet light (EUV), etc. 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. A chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. Moreover, before the development, the steps of applying a resist composition, drying, exposing, and heating may be repeatedly performed on the exposed composition layer.
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.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove water remaining on the substrate and pattern.
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 very small 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 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 suitable as a resist composition for line (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 structure of the compound was confirmed by MASS (LC: 1100 type manufactured by Agilent, MASS: LC/MSD type or LC/MSD TOF type manufactured by Agilent).
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 HXL-M x 3+guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min
Detector: RI detector Column temperature: 40℃
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

Synthesis of Resin Compounds (monomers) used for synthesizing Resin (A1) and Resin (A2) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-1-3)" and the like according to their formula numbers.

Synthesis Example 1 [Synthesis of Resin A1-1]
Monomer (I'-8) and monomer (III'-1) are used as monomers, and mixed so that the molar ratio (monomer (I'-8):monomer (III'-1)) is 50:50. Then, propylene glycol monomethyl ether acetate was added in an amount of 2 times the total amount of monomers to form a solution. To this solution, 1 mol % and 3 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The resulting reaction mixture is poured into a large amount of n-heptane to precipitate the resin, and the resin is filtered to give a resin A1-1 (copolymer) having a weight average molecular weight of 1.6×10 ⁴ with a yield of 94%. I got it in This resin A1-1 has the following structural units.

Synthesis Example 2 [Synthesis of resin A1-2]
Monomer (I'-8) and monomer (III'-1) are used as monomers, and mixed so that the molar ratio (monomer (I'-8):monomer (III'-1)) is 50:50. Then, propylene glycol monomethyl ether acetate was added in an amount of 2 times the total amount of monomers to form a solution. To this solution was added 4.5 mol % of 2,2'-azobis(isobutyrate)dimethyl as an initiator based on the total amount of monomers, and the mixture was heated at 75° C. for about 5 hours. The obtained reaction mixture is poured into a large amount of n-heptane to precipitate the resin, and the resin is filtered to give a resin A1-2 (copolymer) having a weight average molecular weight of 1.7×10 ⁴ with a yield of 93%. I got it in This resin A1-2 has the following structural units.

Synthesis Example 3 [Synthesis of resin A1-3]
Monomer (I'-8) and monomer (III'-1) are used as monomers, and mixed so that the molar ratio (monomer (I'-8):monomer (III'-1)) is 40:60. Then, propylene glycol monomethyl ether acetate was added in an amount of 2 times the total amount of monomers to form a solution. To this solution, 0.9 mol % and 2.7 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were stirred at 75°C. Heated for about 5 hours. The resulting reaction mixture was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered to give a resin A1-3 (copolymer) having a weight average molecular weight of 1.8×10 ⁴ with a yield of 93%. I got it in This resin A1-3 has the following structural units.

Synthesis Example 4 [Synthesis of resin A1-4]
Monomer (I'-8) and monomer (III'-1) are used as monomers, and mixed so that the molar ratio (monomer (I'-8):monomer (III'-1)) is 30:70. Then, propylene glycol monomethyl ether acetate was added in an amount of 2 times the total amount of monomers to form a solution. To this solution, 0.75 mol % and 2.25 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively. Heated for about 5 hours. The resulting reaction mixture is poured into a large amount of n-heptane to precipitate the resin, and the resin is filtered to give a resin A1-4 (copolymer) having a weight average molecular weight of 1.8×10 ⁴ with a yield of 95%. I got it in This resin A1-4 has the following structural units.

Synthesis Example 5 [Synthesis of resin A1-5]
Monomer (I'-8) and monomer (III'-1) are used as monomers, and mixed so that the molar ratio (monomer (I'-8):monomer (III'-1)) is 50:50. Then, propylene glycol monomethyl ether acetate was added in an amount 1.5 times the mass of the total amount of monomers to form a solution. To this solution, 2 mol % and 6 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture is poured into a large amount of n-heptane to precipitate the resin, and the resin is filtered to give a resin A1-5 (copolymer) having a weight average molecular weight of 1.2×10 ⁴ with a yield of 94%. I got it in This resin A1-5 has the following structural units.

Synthesis Example 6 [Synthesis of resin A1-6]
Monomer (I'-9) and monomer (III'-1) are used as monomers, and mixed so that the molar ratio (monomer (I'-9):monomer (III'-1)) is 50:50. Then, propylene glycol monomethyl ether acetate was added in an amount of 2 times the total amount of monomers to form a solution. To this solution, 1 mol % and 3 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The resulting reaction mixture is poured into a large amount of n-heptane to precipitate the resin, and the resin is filtered to give a resin A1-6 (copolymer) having a weight average molecular weight of 1.6×10 ⁴ with a yield of 95%. I got it in This resin A1-6 has the following structural units.

Synthesis Example 7 [Synthesis of resin A1-7]
Monomer (I'-14) and monomer (III'-1) are used as monomers, and mixed so that the molar ratio (monomer (I'-14):monomer (III'-1)) is 50:50. Then, propylene glycol monomethyl ether acetate was added in an amount of 2 times the total amount of monomers to form a solution. To this solution, 1 mol % and 3 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The resulting reaction mixture is poured into a large amount of n-heptane to precipitate the resin, and the resin is filtered to give a resin A1-7 (copolymer) having a weight average molecular weight of 1.6×10 ⁴ with a yield of 89%. I got it in This resin A1-7 has the following structural units.

Synthesis Example 8 [Synthesis of Resin A1-8]
Monomer (I'-8) and monomer (a2-1-1) are used as monomers, and the molar ratio (monomer (I'-8):monomer (a2-1-1)) is adjusted to 50:50. and propylene glycol monomethyl ether acetate in an amount of 2 times the total amount of monomers was added to form a solution. To this solution, 1 mol % and 3 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The resulting reaction mixture was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered to give a resin A1-8 (copolymer) having a weight average molecular weight of 1.6×10 ⁴ with a yield of 82%. I got it in This resin A1-8 has the following structural units.

Synthesis Example 9 [Synthesis of Resin A1-9]
Monomer (I'-8) and monomer (III'-1a) are used as monomers, and mixed so that the molar ratio (monomer (I'-8):monomer (III'-1a)) is 50:50. Then, propylene glycol monomethyl ether acetate was added in an amount of 2 times the total amount of monomers to form a solution. To this solution, 1 mol % and 3 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The obtained reaction mixture is poured into a large amount of n-heptane to precipitate the resin, and the resin is filtered to give a resin A1-9 (copolymer) having a weight average molecular weight of 1.8×10 ⁴ with a yield of 96%. I got it in This resin A1-9 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A1-10]
Monomer (I'-8) and monomer (III'-10) are used as monomers, and mixed so that the molar ratio (monomer (I'-8):monomer (III'-10)) is 50:50. Then, propylene glycol monomethyl ether acetate was added in an amount of 2 times the total amount of monomers to form a solution. To this solution, 1 mol % and 3 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The resulting reaction mixture was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered to give a resin A1-10 (copolymer) having a weight average molecular weight of 1.7×10 ⁴ with a yield of 91%. I got it in This resin A1-10 has the following structural units.

Synthesis Example 11 [Synthesis of Resin A1-11]
As monomers, monomer (I'-8) and monomer (a1-4-13) are used, and the molar ratio (monomer (I'-8):monomer (a1-4-13)) is 50:50. and propylene glycol monomethyl ether acetate in an amount of 2 times the total amount of monomers was added to form a solution. To this solution, 1 mol % and 3 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 75° C. for about 5 hours. did. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount 2.0 times the weight of the total weight of all the monomers, stirred for 6 hours, and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and collected to obtain a resin A1-11 (copolymer) having a weight average molecular weight of 1.7×10 ⁴ with a yield of 82%. I got it in This resin A1-11 has the following structural units.

Synthesis Example 12 [Synthesis of Resin A1-12]
As monomers, monomer (I'-8) and monomer (a1-4-13) are used, and the molar ratio (monomer (I'-8):monomer (a1-4-13)) is 50:50. and propylene glycol monomethyl ether acetate in an amount of 2 times the total amount of monomers was added to form a solution. To this solution was added 4.5 mol % of 2,2'-azobis(isobutyrate)dimethyl as an initiator based on the total amount of monomers, and the mixture was heated at 75° C. for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount 2.0 times the weight of the total weight of all the monomers, stirred for 6 hours, and then separated. The obtained organic layer is poured into a large amount of n-heptane to precipitate the resin, which is then filtered and collected to obtain a resin A1-12 (copolymer) having a weight average molecular weight of 1.6×10 ⁴ with a yield of 80%. I got it in This resin A1-12 has the following structural units.

Synthesis Example 13 [Synthesis of Resin A1-13]
As the monomer, the monomer (I'-8) and the monomer (a1-4-2) are used, and the molar ratio (monomer (I'-8):monomer (a1-4-2)) is adjusted to 50:50. and propylene glycol monomethyl ether acetate in an amount of 2 times the total amount of monomers was added to form a solution. To this solution was added 4.5 mol % of 2,2'-azobis(isobutyrate)dimethyl as an initiator based on the total amount of monomers, and the mixture was heated at 75° C. for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount 2.0 times the weight of the total weight of all the monomers, stirred for 6 hours, and then separated. The obtained organic layer is poured into a large amount of n-heptane to precipitate the resin, which is then filtered and collected to obtain a resin A1-13 (copolymer) having a weight average molecular weight of 1.7×10 ⁴ with a yield of 85%. I got it in This resin A1-13 has the following structural units.

Synthesis Example 14 [Synthesis of Resin A1-14]
As the monomer, the monomer (I'-8) and the monomer (a1-4-19) are used, and the molar ratio (monomer (I'-8):monomer (a1-4-19)) is 50:50. and propylene glycol monomethyl ether acetate in an amount of 2 times the total amount of monomers was added to form a solution. To this solution was added 4.5 mol % of 2,2'-azobis(isobutyrate)dimethyl as an initiator based on the total amount of monomers, and the mixture was heated at 75° C. for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount 2.0 times the weight of the total weight of all the monomers, stirred for 6 hours, and then separated. The resulting organic layer was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and collected to yield 83% of resin A1-14 (copolymer) having a weight average molecular weight of 1.6×10 ⁴ . I got it in This resin A1-14 has the following structural units.

Synthesis Example 15 [Synthesis of resin A1-15]
As monomers, monomer (I'-8) and monomer (a1-4-20) are used, and the molar ratio (monomer (I'-8):monomer (a1-4-20)) is 50:50. and propylene glycol monomethyl ether acetate in an amount of 2 times the total amount of monomers was added to form a solution. To this solution was added 4.5 mol % of 2,2'-azobis(isobutyrate)dimethyl as an initiator based on the total amount of monomers, and the mixture was heated at 75° C. for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount 2.0 times the weight of the total weight of all the monomers, stirred for 6 hours, and then separated. The obtained organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A1-15 (copolymer) having a weight average molecular weight of 1.8×10 ⁴ with a yield of 80%. I got it in This resin A1-15 has the following structural units.

Synthesis Example 16 [Synthesis of resin A1-16]
Monomer (I'-8) and monomer (a2-2-15a) are used as monomers, and the molar ratio (monomer (I'-8):monomer (a2-2-15a)) is adjusted to 50:50. and propylene glycol monomethyl ether acetate in an amount of 2 times the total amount of monomers was added to form a solution. To this solution was added 4.5 mol % of 2,2'-azobis(isobutyrate)dimethyl as an initiator based on the total amount of monomers, and the mixture was heated at 75° C. for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5% by weight) in an amount of 2.0 times the mass of all monomers was added to the polymerization reaction solution, stirred for 6 hours, and separated. The resulting organic layer was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and collected to yield 81% of resin A1-16 (copolymer) having a weight average molecular weight of 1.6×10 ⁴ . I got it in This resin A1-16 has the following structural units.

Synthesis Example 17 [Synthesis of resin AX1-1]
As the monomer, the monomer (I'-9) and the monomer (ax) are used and mixed so that the molar ratio (monomer (I'-9):monomer (ax)) is 50:50. Propylene glycol monomethyl ether acetate was added twice by mass to form a solution. To this solution, 1 mol % and 3 mol % of azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the total amount of monomers, respectively, and these were heated at 75° C. for about 5 hours. did. The resulting reaction mixture was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered to give a resin AX1-1 (copolymer) having a weight average molecular weight of 1.7×10 ⁴ with a yield of 91%. I got it in This resin AX1-1 has the following structural units.

Synthesis Example 18 [Synthesis of Resin A2-1]
As monomers, monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) are used, and the molar ratio [monomer (a1-4-2):monomer (a1-1 -3): Monomer (a1-2-6)] are mixed in a ratio of 38:24:38, and further, 1.5 times the mass of the total mass of all monomers is added to this monomer mixture. of methyl isobutyl ketone 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. Ta. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount 2.0 times the weight of the total weight of all the monomers, stirred for 6 hours, and then separated. The obtained organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A2-1 (copolymer) having a weight average molecular weight of about 5.3×10 ³ . A yield of 78% was obtained. This resin A2-1 has the following structural units.

Synthesis Example 19 [Synthesis of resin A2-2]
As the monomer, the monomer (a1-4-2) and the monomer (a1-2-6) were used, and the molar ratio [monomer (a1-4-2):monomer (a1-2-6)] was 38:62. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all the monomers was mixed with this monomer mixture. 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. Ta. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount 2.0 times the weight of the total weight of all the monomers, stirred for 6 hours, and then separated. The obtained organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A2-2 (copolymer) having a weight average molecular weight of about 5.4×10 ³ . A yield of 89% was obtained. This resin A2-2 has the following structural units.

Synthesis Example 20 [Synthesis of resin A2-3]
As monomers, the monomer (a1-4-2), the monomer (a1-2-6) and the monomer (bx) are used, and the molar ratio [monomer (a1-4-2):monomer (a1-2-6): Monomer (bx)] were mixed at a ratio of 44:44:12, and propylene glycol monomethyl ether acetate was added to the monomer mixture in an amount 2.5 times the total amount of monomers to form a solution. To this solution was added 7.5 mol % of 2,2'-azobis(isobutyrate)dimethyl as an initiator based on the total amount of monomers, and the mixture was heated at 85° C. for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount 2.0 times the weight of the total weight of all the monomers, stirred for 6 hours, and then separated. The obtained organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A2-3 (copolymer) having a weight average molecular weight of about 6.3×10 ³ . A yield of 76% was obtained. This resin A2-3 has the following structural units.

<Preparation of resist composition>
As shown in Table 1, a resist composition was prepared by mixing the following components and filtering the resulting mixture through a fluororesin filter having a pore size of 0.2 μm.

＜クエンチャー（Ｃ）＞
Ｃ１：（特開２０２０－０１５７１３号公報の実施例を参考にして合成）

＜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 ３００部
γ－ブチロラクトン ２０部 <Resin>
A1-1 to A1-16, A2-1 to A2-3, AX1-1: Resin A1-1 to Resin A1-16, Resin A2-1 to Resin A2-3, Resin AX1-1
<Acid generator (B)>
B1-57: a salt represented by the formula (B1-57) (synthesized with reference to the examples of JP-A-2020-015713)

<Quencher (C)>
C1: (synthesized with reference to the examples of JP-A-2020-015713)

<Solvent>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 300 parts γ-butyrolactone 20 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 on a direct hot plate at the temperature shown in the "PB" column of Table 1 for 60 seconds to form a composition layer. A contact hole pattern (hole pitch 40 nm/hole diameter 17 nm) was directly written.
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.

In the resist pattern obtained after development, the effective sensitivity was defined as the amount of exposure at which the hole diameter formed was 17 nm.

<CD uniformity (CDU) evaluation>
In the effective sensitivity, the hole diameter of a pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. A standard deviation was obtained by using a population of 400 measured average hole diameters of patterns formed with a hole diameter of 17 nm in the same wafer.
Table 2 shows the results. Numerical values in the table indicate standard deviations (nm).

<Defect evaluation>
The resist composition was applied (spin-coated) onto a 12-inch silicon wafer (substrate) so that the film thickness after drying was 0.04 μm. After coating, it was pre-baked (PB) for 60 seconds on a direct hot plate at the temperature shown in the PB column of Table 1 to form a composition layer on the wafer.
The wafer on which the composition layer was formed in this manner was subjected to post-exposure baking for 60 seconds at the temperature shown in the PEB column of Table 1, and further subjected to puddle development for 60 seconds with a 2.38% by mass tetramethylammonium hydroxide aqueous solution. By doing so, a resist pattern was obtained.
After that, the number of defects on the wafer was measured using a defect inspection device [KLA-2810; manufactured by KLA-Tencor]. Table 2 shows the results.

Compositions 1-25 had better CD uniformity (CDU) ratings and fewer defects compared to Comparative Compositions 1-3.

The resist composition of the present invention has few defects and good CD uniformity (CDU), and is useful for fine processing of semiconductors.

Claims (9)

(A1) a resin comprising a structural unit represented by formula (I) and a structural unit represented by formula (III);
(A2) a resin having an acid-labile group, and
A resist composition containing an acid generator.

[in the formula (I),
R ¹ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
X ¹ represents *-CO-O-. * represents the binding site to the carbon atom to which ^R1 binds.
L ¹ represents an optionally substituted chain hydrocarbon group having 1 to 28 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —S—, — SO ₂ - or -CO- may be substituted.
R ² represents a fluorinated alkyl group having 1 to 8 carbon atoms.
R ³ represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
mi represents an integer of 1 to 4; ]

[In the formula (III),
R ⁴ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
^X2 represents a single bond or *-CO-O-. * represents the binding site to the carbon atom to which ^R4 binds.
L ² represents a single bond or an optionally substituted hydrocarbon group having 1 to 28 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —S—, — SO ₂ - or -CO- may be substituted.
mk represents an integer of 1-4. ] 2. The resist composition according to claim ¹ , wherein L 1 is an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms. 2. The resist composition according to claim 1, wherein the structural unit represented by formula (I) is a structural unit represented by formula (I-1).

[In the formula (I-1),
R ¹ , X ¹ , R ² and R ³ represent the same as in formula (I).
L ¹⁰ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and —CH ₂ — contained in the alkanediyl group may be replaced with —O— or —CO—. When mi1 is 2 or more, a plurality of ^L10 may be the same or different.
R ¹⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms (-CH ₂ - contained in the alicyclic hydrocarbon group is -O- or - may be substituted with CO—.The alicyclic hydrocarbon group may have a substituent.) or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group is may have a substituent). When mi2 is 2 or more, multiple R ¹⁰ may be the same or different.
mi1 represents an integer of 1 to 3;
mi2 represents an integer that satisfies 3-mi1. ] L ² is a chain hydrocarbon group having 1 to 9 carbon atoms (-CH ₂ - contained in the chain hydrocarbon group may be replaced with -O- or -CO-); to 12 alicyclic hydrocarbon groups (-CH ₂ - contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO ₂ -). or an aromatic hydrocarbon group having 6 to 10 carbon atoms (the aromatic hydrocarbon group is one or more halogen atoms, one or more alkyl groups having 1 to 3 carbon atoms, one or more haloalkyl groups having 1 to 3 carbon atoms or one or more alkoxy groups having 1 to 3 carbon atoms). (A2) resin having an acid-labile group is a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), and a structural unit represented by formula (a1-2) 2. The resist composition according to claim 1, comprising at least one selected from the group consisting of:

[In formula (a1-0), formula (a1-1) and formula (a1-2),
L ^a01 , L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, k1 represents an integer of 1 to 7, * is represents the binding site with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom, a halogen atom or an optionally halogenated alkyl group having 1 to 6 carbon atoms.
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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or Represents a combined group.
R ^a6 and R ^a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. It represents a hydrocarbon group or a group formed by combining these groups.
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 resist composition according to claim 1, wherein (A2) a resin having an acid-labile group comprises a structural unit represented by formula (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 alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, It represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51 -(A ^a52 -X ^a52 ) _nb -, and * represents a bonding site with the carbon atom to which -R ^a50 bonds.
A ^a52 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. ] 2. The resist composition according to claim 1, wherein the acid generator contains a salt represented by formula (B1).

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms or a perfluoroalkyl group having 1 to 6 carbon atoms.
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 24 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S-, -SO ₂ - or -CO-.
Z1 ⁺ represents an organic cation. ] 2. The resist composition according to claim 1, 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 1 to 8 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: