JP7188976B2 - Salt, acid generator, resin, resist composition, and method for producing resist pattern - Google Patents

Description

The present invention relates to a salt for an acid generator used in semiconductor microfabrication, an acid generator containing the salt, a resin containing a structural unit derived from the salt, a resist composition, and a method for producing a resist pattern.

特許文献２には、下記式で表される塩に由来する構造単位を含む樹脂及び該樹脂を含有するレジスト組成物が記載されている。

特許文献３には、下記式で表されるアニオンからなる塩に由来する構造単位を含む樹脂、及び該樹脂を含有するレジスト組成物が記載されている。

Patent Document 1 describes a resin containing a structural unit derived from a salt represented by the following formula and a resist composition containing the resin.

Patent Document 2 describes a resin containing a structural unit derived from a salt represented by the following formula and a resist composition containing the resin.

Patent Document 3 describes a resin containing a structural unit derived from a salt consisting of an anion represented by the following formula, and a resist composition containing the resin.

JP 2011-190246 A JP 2014-197168 A JP 2011-154216 A

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

［式（Ｉ）中、
Ｑ^１及びＱ^２は、それぞれ独立に、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｒ^１及びＲ^２は、それぞれ独立に、水素原子、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
ｚは、０～６のいずれかの整数を表し、ｚが２以上のとき、複数のＲ^１及びＲ^２は互いに同一であっても異なってもよい。
Ｘ¹は、＊－ＣＯ－Ｏ－、＊－Ｏ－ＣＯ－、＊－Ｏ－ＣＯ－Ｏ－又は＊－Ｏ－（但し、＊は、Ｃ（Ｒ¹）（Ｒ²）又はＣ（Ｑ¹）（Ｑ²）との結合位を表す。）を表す。
Ｌ^１は、単結合又は置換基を有していてもよい炭素数１～３６の２価の炭化水素基を表し、該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。
Ａｒは、置換基を有していてもよい炭素数６～３６の芳香族炭化水素基を表す。
Ｒ^３は、炭素数１～６の炭化水素基を表す。
Ｒ^４は、水素原子又は炭素数１～６の炭化水素基を表す。
Ｒ^５は、水素原子又はメチル基を表す。
ＺＩ^＋は有機カチオンを表す。］
［２］Ｘ¹が、＊－ＣＯ－Ｏ－、＊－Ｏ－ＣＯ－又は＊－Ｏ－ＣＯ－Ｏ－（但し、＊は、Ｃ（Ｒ¹）（Ｒ²）又はＣ（Ｑ¹）（Ｑ²）との結合位を表す。）である［１］に記載の塩。
［３］Ｌ¹が、単結合、炭素数１～６のアルカンジイル基又は炭素数１～６のアルカンジイル基と炭素数３～１８の脂環式炭化水素基とを組み合わせた基（但し、該アルカンジイル基及び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。）である［１］又は［２］記載の塩。
［４］Ａｒが、置換基を有していてもよいフェニレン基である［１］～［３］のいずれかに記載の塩。
［５］［１］～［４］のいずれかに記載の塩を含有する酸発生剤。
［６］［１］～［４］のいずれかに記載の塩に由来する構造単位を有する樹脂。
［７］さらに、酸不安定基を有する構造単位を含む［６］記載の樹脂。
［８］［６］又は［７］記載の樹脂と、酸発生剤とを含むレジスト組成物。
［９］酸発生剤が、式（Ｂ１）で表される塩を含む［８］記載のレジスト組成物。

［式（Ｂ１）中、
Ｑ^ｂ１及びＱ^ｂ２は、それぞれ独立に、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｌ^ｂ１は、炭素数１～２４の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３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ（Ｏ）_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］
［１０］［５］記載の酸発生剤と酸不安定基を有する樹脂とを含有するレジスト組成物。
［１１］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含有する［８］～［１０］のいずれかに記載のレジスト組成物。
［１２］（１）［８］～［１１］のいずれかに記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A salt represented by formula (I).

[in the formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom or a C 1-6 perfluoroalkyl group.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² may be the same or different.
X ¹ is *-CO-O-, *-O-CO-, *-O-CO-O- or *-O- (where * is C (R ¹ ) (R ² ) or C (Q ¹ ) represents the bonding position with (Q ² ).
L ¹ represents a single bond or an optionally substituted divalent hydrocarbon group having 1 to 36 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —S -, -CO- or -SO ₂ - may be substituted.
Ar represents an optionally substituted aromatic hydrocarbon group having 6 to 36 carbon atoms.
R ³ represents a hydrocarbon group having 1 to 6 carbon atoms.
R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.
^R5 represents a hydrogen atom or a methyl group.
ZI ⁺ represents an organic cation. ]
[2] X ¹ is *-CO-O-, *-O-CO- or *-O-CO-O- (where * is C (R ¹ ) (R ² ) or C (Q ¹ ) The salt according to [1], which represents the bonding position with (Q ² ).
[3] L ¹ is a single bond, an alkanediyl group having 1 to 6 carbon atoms, or a group obtained by combining an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that —CH ₂ — contained in the alkanediyl group and the alicyclic hydrocarbon group may be replaced with —O—, —S—, —CO— or —SO ₂ —.) [1]. Or the salt according to [2].
[4] The salt according to any one of [1] to [3], wherein Ar is an optionally substituted phenylene group.
[5] An acid generator containing the salt according to any one of [1] to [4].
[6] A resin having a structural unit derived from the salt according to any one of [1] to [4].
[7] The resin according to [6], which further contains a structural unit having an acid-labile group.
[8] A resist composition comprising the resin according to [6] or [7] and an acid generator.
[9] The resist composition according to [8], wherein the acid generator contains a salt represented by formula (B1).

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a 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—; A hydrogen atom contained in may be substituted with a fluorine atom or a hydroxy group.
Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S(O) ₂ - or -CO-.
Z ⁺ represents an organic cation. ]
[10] A resist composition containing the acid generator described in [5] and a resin having an acid-labile group.
[11] The resist composition according to any one of [8] to [10], which contains a salt that generates an acid weaker in acidity than the acid generated from the acid generator.
[12] (1) a step of applying the resist composition according to any one of [8] to [11] onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) A process of heating the composition layer after exposure, and (5) a process of developing the composition layer after heating.

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

As used herein, the term “(meth)acrylic monomer” refers to a monomer having a structure of “CH ₂ ═CH—CO—” and a monomer having a structure of “CH ₂ ═C(CH ₃ )—CO—”. means at least one selected from the group consisting of Similarly, "(meth)acrylate" and "(meth)acrylic acid" are respectively "at least one selected from the group consisting of acrylates and methacrylates" and "at least one selected from the group consisting of acrylic acid and methacrylic acid." ” means. Where structural units having "CH ₂ =C(CH ₃ )-CO-" or "CH ₂ =CH-CO-" are exemplified, structural units having both groups are similarly exemplified. shall be In addition, among the groups described in this specification, any group that can have both a linear structure and a branched structure may be used. 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.

<Salt Represented by Formula (I)>
The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)").
In the salt (I), the negatively charged side is sometimes called "anion (I)", and the positively charged side is sometimes called "cation (I)".

In formula (I), the perfluoroalkyl groups for Q ¹ , Q ² , R ¹ and R ² include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group and perfluorosec-butyl group. , perfluorotert-butyl group, perfluoropentyl group, perfluorohexyl group and the like.
Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.
R ¹ and R ² are each independently preferably a hydrogen atom or a fluorine atom.
z is preferably zero.

X ¹ is *-CO-O-, *-O-CO- or *-O-CO-O- (where * is C(R ¹ )(R ² ) or C(Q ¹ )(Q ² ) is preferably *—CO—O— or *—O—CO— (where * is C(R ¹ )(R ² ) or C(Q ¹ ) represents the bonding position with (Q ² ).) is more preferred.
Examples of the divalent hydrocarbon group having 1 to 36 carbon atoms for L ¹ include an alkanediyl group, a monocyclic or polycyclic alicyclic hydrocarbon group, an aromatic hydrocarbon group, and the like. It may be a divalent hydrocarbon group obtained by combining two or more of the above.

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 alkanediyl groups such as groups;
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 can be mentioned.
The monocyclic alicyclic hydrocarbon groups include cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclohexene-3,6-diyl group, A cycloalkanediyl group such as a cyclooctane-1,5-diyl group can be mentioned.
Polycyclic alicyclic hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, 5-norbornene-2,3-diyl group and adamantane-1,5-diyl group , adamantane-2,6-diyl group and the like.
The divalent aromatic hydrocarbon group includes a phenylene group, naphthylene group, anthrylene group, biphenylene group, phenanthrylene group and the like.
Hydrocarbon groups in which two or more types are combined include groups in which an alkanediyl group and an alicyclic hydrocarbon group and/or an aromatic hydrocarbon group are combined, and the like, *-cycloalkanediyl group-alkanediyl group -, *-alkanediyl group-cycloalkanediyl group-, *-alkanediyl group-cycloalkanediyl group-alkanediyl group-, *-alkanediyl group-aromatic hydrocarbon group-, *-aromatic hydrocarbon group -alkanediyl group-, etc. (* represents a bond with X ¹ ).

Substituents possessed by the hydrocarbon group of L ¹ include a hydroxy group, a cyano group, a carboxyl group, an alkoxy group having 1 to 12 carbon atoms, an acyl group having 2 to 13 carbon atoms, an acyloxy group having 2 to 13 carbon atoms, and these A group in which two or more of the groups are combined may be mentioned.
Examples of alkoxy groups having 1 to 12 carbon atoms include methoxy, ethoxy, propoxy, butoxy, pentyloxy and hexyloxy groups.
The acyl group having 2 to 13 carbon atoms includes acetyl group, propionyl group and butyryl group.
The acyloxy group having 2 to 13 carbon atoms includes acetyloxy group, propionyloxy group, butyryloxy group and the like.
The divalent hydrocarbon group having 1 to 36 carbon atoms represented by L ¹ may have one or more substituents.

—CH ₂ — contained in the divalent hydrocarbon group having 1 to 36 carbon atoms in L ¹ may be replaced with —O—, —S—, —CO— or —SO ₂ —.
When the divalent hydrocarbon group having 1 to 36 carbon atoms in L ¹ has a substituent, or —CH ₂ — contained in the hydrocarbon group is —O—, —S—, —CO— or —SO ₂ — is substituted, the number of carbon atoms before the substitution is taken as the number of carbon atoms in the hydrocarbon group.

L ¹ is preferably a single bond, an alkanediyl group having 1 to 6 carbon atoms, or a group obtained by combining an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms. In this case, --CH ₂ -- contained in L ¹ may be further replaced with --O--, --S--, --CO-- or --SO ₂ --. In particular, L ¹ is a single bond, *-alkanediyl group-cycloalkanediyl group-alkanediyl group- or *-cycloalkanediyl group-alkanediyl group- (* represents a bond with X ¹ ). more preferred.

炭素数６～１０の芳香族炭化水素基としては、フェニル基、ナフチル基、トリル基、キシリル基、シクロヘキシルフェニル基等が挙げられる。
芳香族炭化水素基の置換基における組み合わせた基としては、ヒドロキシ基と炭素数１～１２のアルキル基とを組み合わせた基、炭素数１～１２のアルコキシ基と炭素数１～１２のアルコキシ基とを組み合わせた基、炭素数１～１２のアルキル基と炭素数６～１０の芳香族炭化水素基とを組み合わせた基等が挙げられる。
ヒドロキシ基と炭素数１～１２のアルキル基とを組み合わせた基としては、ヒドロキシメチル基、ヒドロキシエチル基等の炭素数１～１２のヒドロキシアルキル基等が挙げられる。
炭素数１～１２のアルコキシ基と炭素数１～１２のアルコキシ基とを組み合わせた基としては、エトキシエトキシ基等の炭素数２～２４のアルコキシアルコキシ基等が挙げられる。
炭素数１～１２のアルキル基と炭素数６～１０の芳香族炭化水素基とを組み合わせた基としては、ベンジル基等の炭素数７～２２のアラルキル基等が挙げられる。
Ａｒとしては、置換基を有していてもよいフェニレン基であることが好ましい。この場合、置換基としては、ハロゲン原子及びヒドロキシ基等が好ましい。 The aromatic hydrocarbon group for Ar includes arylene groups having 6 to 36 carbon atoms such as phenylene group, naphthylene group and anthrylene group.
The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, more preferably 6 to 18 carbon atoms.
Substituents for the aromatic hydrocarbon group include a hydroxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 13 carbon atoms, and an alkoxycarbonyl group having 2 to 13 carbon atoms. 2 to 13 alkylcarbonyl groups, C 2 to 13 alkylcarbonyloxy groups, C 3 to C 12 alicyclic hydrocarbon groups, C 6 to C 10 aromatic hydrocarbon groups, groups combining these, etc. is mentioned. Only one of these substituents may be substituted, or two or more substituents may be substituted.
Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
Examples of alkyl groups having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group. .
Examples of alkoxy groups having 1 to 12 carbon atoms include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, and undecyloxy. group, dodecyloxy group, and the like.
An alkoxycarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms and an alkylcarbonyloxy group having 2 to 13 carbon atoms are groups in which a carbonyl group or a carbonyloxy group is bonded to the alkyl group or alkoxy group described above. represents The alkoxycarbonyl group having 2 to 13 carbon atoms includes methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group and the like, and the alkylcarbonyl group having 2 to 13 carbon atoms includes acetyl group, propionyl group, butyryl group and the like. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include acetyloxy group, propionyloxy group and butyryloxy group.
The alicyclic hydrocarbon group having 3 to 12 carbon atoms may be either monocyclic or polycyclic, and examples thereof include the groups shown below. ** is a bond with an aromatic hydrocarbon group.

The aromatic hydrocarbon group having 6 to 10 carbon atoms includes phenyl group, naphthyl group, tolyl group, xylyl group, cyclohexylphenyl group and the like.
Examples of the combined group in the substituent of the aromatic hydrocarbon group include a group combining a hydroxy group and an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms. and a group obtained by combining an alkyl group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms.
Groups in which a hydroxy group and an alkyl group having 1 to 12 carbon atoms are combined include a hydroxyalkyl group having 1 to 12 carbon atoms such as a hydroxymethyl group and a hydroxyethyl group.
Examples of groups in which an alkoxy group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms are combined include alkoxyalkoxy groups having 2 to 24 carbon atoms such as an ethoxyethoxy group.
Examples of groups in which an alkyl group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms are combined include an aralkyl group having 7 to 22 carbon atoms such as a benzyl group.
Ar is preferably a phenylene group which may have a substituent. In this case, the substituent is preferably a halogen atom, a hydroxy group, or the like.

Hydrocarbon groups having 1 to 6 carbon atoms for R ³ and R ⁴ include methyl group, ethyl group, propyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group. Alkyl groups; cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group; and aromatic hydrocarbon groups such as a phenyl group.
R ³ is preferably a saturated hydrocarbon group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and preferably a linear alkyl group having 1 to 6 carbon atoms. More preferably, it is a methyl group or an ethyl group, even more preferably a methyl group.
R ⁴ is preferably a hydrogen atom or a C 1-6 saturated hydrocarbon group, more preferably a hydrogen atom or a C 1-6 alkyl group, and a hydrogen atom or a C 1-6 A straight-chain alkyl group is more preferred, a hydrogen atom or a methyl group is even more preferred, and a hydrogen atom is even more preferred.
In particular, R ³ is preferably an alkyl group and R ⁴ is a hydrogen atom, more preferably R ³ is a methyl group or an ethyl group and R ⁴ is a hydrogen atom.

Examples of the anion (I) include the following anions. Among them, formula (Ia-1) ~ formula (Ia-3), formula (Ia-5), formula (Ia-7) ~ formula (Ia-9), formula (Ia-11) ~ formula (Ia-16 ), formula (Ia-21), formula (Ia-22) anions represented by formula (Ia-1) ~ formula (Ia-3), formula (Ia-5), formula (Ia-11) , Formula (Ia-12), Formula (Ia-14) to Formula (Ia-16), and Formula (Ia-22) are preferred.

A compound in which the methyl group corresponding to R5 is replaced with a hydrogen atom can also be given as a specific example of the anion ⁽ I).

Organic cations of ZI ⁺ 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.

式（ｂ２－１）～式（ｂ２－４）において、
Ｒ^b4～Ｒ^b6は、それぞれ独立に、炭素数１～３０の鎖式炭化水素基、炭素数３～３６の脂環式炭化水素基又は炭素数６～３６の芳香族炭化水素基を表し、該鎖式炭化水素基に含まれる水素原子は、ヒドロキシ基、炭素数１～１２のアルコキシ基、炭素数３～１２の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基で置換されていてもよく、該脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、炭素数１～１８の脂肪族炭化水素基、炭素数２～４のアルキルカルボニル基又はグリシジルオキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基又は炭素数１～１２のアルコキシ基で置換されていてもよい。
Ｒ^b4とＲ^b5とは、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b7及びＲ^b8は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
ｍ２及びｎ２は、それぞれ独立に０～５のいずれかの整数を表す。
ｍ２が２以上のとき、複数のＲ^b7は同一でも異なってもよく、ｎ２が２以上のとき、複数のＲ^b8は同一でも異なってもよい。
Ｒ^b9及びＲ^b10は、それぞれ独立に、炭素数１～３６の鎖式炭化水素基又は炭素数３～３６の脂環式炭化水素基を表す。
Ｒ^b9とＲ^b10とは、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b11は、水素原子、炭素数１～３６の鎖式炭化水素基、炭素数３～３６の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基を表す。
Ｒ^b12は、炭素数１～１２の鎖式炭化水素基、炭素数３～１８の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基を表し、該鎖式炭化水素に含まれる水素原子は、炭素数６～１８の芳香族炭化水素基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、炭素数１～１２のアルコキシ基又は炭素数１～１２のアルキルカルボニルオキシ基で置換されていてもよい。
Ｒ^b11とＲ^b12とは、互いに結合してそれらが結合する－ＣＨ－ＣＯ－を含めて環を形成していてもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b13～Ｒ^b18は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
Ｌ^b31は、硫黄原子又は酸素原子を表す。
ｏ２、ｐ２、ｓ２、及びｔ２は、それぞれ独立に、０～５のいずれかの整数を表す。
ｑ２及びｒ２は、それぞれ独立に、０～４のいずれかの整数を表す。
ｕ２は０又は１を表す。
ｏ２が２以上のとき、複数のＲ^b13は同一又は相異なり、ｐ２が２以上のとき、複数のＲ^b14は同一又は相異なり、ｑ２が２以上のとき、複数のＲ^b15は同一又は相異なり、ｒ２が２以上のとき、複数のＲ^b16は同一又は相異なり、ｓ２が２以上のとき、複数のＲ^b17は同一又は相異なり、ｔ２が２以上のとき、複数のＲ^b18は同一又は相異なる。

In formulas (b2-1) to (b2-4),
R ^b4 to R ^b6 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 36 carbon atoms; The hydrogen atom contained in the chain hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. It may be substituted, and the hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group. It may be substituted, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S— or -CO- may be substituted.
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5;
When m2 is 2 or more, multiple R ^b7 may be the same or different, and when n2 is 2 or more, multiple R ^b8 may be the same or different.
R ^b9 and R ^b10 each independently represent a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S— or -CO- may be substituted.
R ^b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atoms contained in the aromatic hydrocarbon group are alkoxy groups having 1 to 12 carbon atoms or 1 to 1 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may be bonded to each other to form a ring including —CH—CO— to which they are bonded, and —CH ₂ — contained in the ring may be —O—, —S - or -CO- may be substituted.
R ^b13 to R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5;
q2 and r2 each independently represent an integer of 0 to 4;
u2 represents 0 or 1;
When o2 is 2 or more, multiple R ^b13 are the same or different, when p2 is 2 or more, multiple R ^b14 are the same or different, and when q2 is 2 or more, multiple R ^b15 are the same or different. , when r2 is 2 or more, the plurality of R ^b16 are the same or different; when s2 is 2 or more, the plurality of R ^b17 are the same or different; when t2 is 2 or more, the plurality of R ^b18 are the same or different; different.

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.

Aromatic hydrocarbon groups include aryl groups such as phenyl, biphenylyl, naphthyl, and phenanthryl groups.
The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group having a chain hydrocarbon group having 1 to 18 carbon atoms (tolyl group , xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and 3 to 18 carbon atoms (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) having an alicyclic hydrocarbon group of
Aromatic hydrocarbon groups in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group and the like.
Chain hydrocarbon groups in which hydrogen atoms are substituted with aromatic hydrocarbon groups include aralkyl groups such as benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl and naphthylethyl groups.

Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups.
An acetyl group, a propionyl group, a butyryl group, etc. are mentioned as an alkylcarbonyl group.
Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
The alkylcarbonyloxy group includes a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group and a pentylcarbonyloxy group. , hexylcarbonyloxy group, octylcarbonyloxy group and 2-ethylhexylcarbonyloxy group.

The ring formed by R ^b4 and R ^b5 bonded together with the sulfur atom to which they are bonded may be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. may be a ring of This ring includes a ring having 3 to 18 carbon atoms, preferably a ring having 4 to 18 carbon atoms. Further, the ring containing a sulfur atom includes a 3- to 12-membered ring, preferably a 3- to 7-membered ring, and examples thereof include the following rings. * 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 include thiolan-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, 1,4-oxathian-4-ium ring and the like.
The ring formed by R ^b11 and R ^b12 together may be a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. This ring includes a 3- to 12-membered ring, preferably a 3- to 7-membered ring. oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring, oxoadamantane ring and the like.

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

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

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

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

Salts (I) include salts listed in Table 1. For example, in Table 1, salt (I-1) is a salt consisting of an anion represented by formula (Ia-1) and a cation represented by formula (b2-c-1), and the following salts be.

Among them, salt (I) includes salt (I-1) to salt (I-3), salt (I-5), salt (I-7) to salt (I-9), salt (I-11) ~ Salt (I-16), Salt (I-21), Salt (I-22), Salt (I-25) ~ Salt (I-27), Salt (I-29), Salt (I-31) ~ Salt (I-33), Salt (I-35) to Salt (I-40), Salt (I-45), Salt (I-46), Salt (I-49) to Salt (I-51), Salt (I-53), salt (I-55) to salt (I-57), salt (I-59) to salt (I-64), salt (I-69), salt (I-70), salt ( I-73) ~ Salt (I-75), Salt (I-77), Salt (I-79) ~ Salt (I-81), Salt (I-83) ~ Salt (I-88), Salt (I -93), salt (I-94), salt (I-97) to salt (I-99), salt (I-101), salt (I-103) to salt (I-105), salt (I- 107) to salt (I-112), salt (I-117), salt (I-118), salt (I-121) to salt (I-123), salt (I-125), salt (I-127 ) to salt (I-129), salt (I-131) to salt (I-136), salt (I-141), salt (I-142), salt (I-145) to salt (I-147) , Salt (I-149), Salt (I-151) ~ Salt (I-153), Salt (I-155) ~ Salt (I-160), Salt (I-165), Salt (I-166) preferable.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。
式（Ｉ１－ａ）で表される塩としては、例えば、以下で表される塩などが挙げられ、特開２００７－１９７７１８号公報に記載された方法を参考にして製造することができる。

式（Ｉ１－ｂ）で表される化合物としては、例えば、以下で表される化合物が挙げられ、市場より容易に入手できる。

<Method for producing salt (I)>
X ¹ is ^a salt ( ^{formula ( I1} )) can be obtained, for example, by reacting a salt represented by formula (I1-a) with carbonyldiimidazole in a solvent, and then further reacting a compound represented by formula (I1-b) with It can be produced by reacting.

(In the formula, all symbols have the same meanings as described above.)
Examples of solvents include chloroform and acetonitrile.
The reaction temperature is generally 5° C. to 80° C., and the reaction time is generally 0.5 hour to 24 hours.
Examples of the salt represented by the formula (I1-a) include salts represented by the following, which can be produced with reference to the method described in JP-A-2007-197718.

Compounds represented by formula (I1-b) include, for example, compounds represented by the following, which are readily available on the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
酸としては、ｐ－トルエンスルホン酸、塩酸などが挙げられる。
溶媒としては、メチルイソブチルケトン、テトラヒドロフラン、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 Further, the compound represented by formula (I1-b) can be produced, for example, by acid-treating the compound represented by formula (I1-c) in a solvent.

(In the formula, all symbols have the same meanings as described above.)
Examples of acids include p-toluenesulfonic acid and hydrochloric acid.
Examples of solvents include methyl isobutyl ketone, tetrahydrofuran, acetonitrile and the like.
The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hour to 24 hours.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
塩基としては、ジメチルアミノピルジン、ピリジン等が挙げられる。
溶媒としては、メチルイソブチルケトン、テトラヒドロフラン、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。
式（Ｉ１－ｅ）で表される化合物としては、例えば、以下で表される化合物が挙げられ、市場より容易に入手できる。

The compound represented by the formula (I1-c) can be obtained, for example, by reacting the compound represented by the formula (I1-d) with the compound represented by the formula (I1-e) in the presence of a base in a solvent. It can be manufactured by

(In the formula, all symbols have the same meanings as described above.)
Examples of the base include dimethylaminopyrdine, pyridine and the like.
Examples of solvents include methyl isobutyl ketone, tetrahydrofuran, acetonitrile and the like.
The reaction temperature is generally 5° C. to 80° C., and the reaction time is generally 0.5 hour to 24 hours.
Compounds represented by formula (I1-e) include, for example, compounds represented by the following, which are readily available on the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
還元剤としては、水素化ホウ素ナトリウム等が挙げられる。
溶媒としては、メチルイソブチルケトン、テトラヒドロフラン、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 Compounds represented by formula (I1-d) in which R ⁴ is a hydrogen atom (compounds represented by formula (I1-d1)) are, for example, compounds represented by formula (I1-f) can be produced by reduction.

(In the formula, all symbols have the same meanings as described above.)
Sodium borohydride etc. are mentioned as a reducing agent.
Examples of solvents include methyl isobutyl ketone, tetrahydrofuran, acetonitrile and the like.
The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hour to 24 hours.

In the compound represented by formula (I1-d), R ⁴ is a hydrocarbon group having 1 to 6 carbon atoms (compound represented by formula (I1-d2)), for example, and can be easily obtained from the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
酸としては、ｐ－トルエンスルホン酸、ｐ－トルエンスルホン酸ピリジニウム塩等が挙げられる。
溶媒としては、メチルイソブチルケトン、テトラヒドロフラン、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 The compound represented by the formula (I1-f) can be obtained, for example, by reacting the compound represented by the formula (I1-g) with the compound represented by the formula (I1-h) in the presence of an acid in a solvent. It can be manufactured by

(In the formula, all symbols have the same meanings as described above.)
Examples of the acid include p-toluenesulfonic acid and pyridinium p-toluenesulfonic acid.
Examples of solvents include methyl isobutyl ketone, tetrahydrofuran, acetonitrile and the like.
The reaction temperature is generally 5° C. to 80° C., and the reaction time is generally 0.5 hour to 24 hours.

Compounds represented by formula (I1-g) include, for example, compounds represented by the following, which are readily available on the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 X ¹ is ^a salt ( ^{formula ( I2} )) can be obtained, for example, by reacting a compound represented by the formula (I2-b) with carbonyldiimidazole in a solvent, and then further reacting the salt represented by the formula (I2-a) with It can be produced by reacting.

(In the formula, all symbols have the same meanings as described above.)
Examples of solvents include chloroform and acetonitrile.
The reaction temperature is generally 5° C. to 80° C., and the reaction time is generally 0.5 hour to 24 hours.

式（Ｉ２－ｂ）で表される化合物としては、例えば、以下で表される化合物が挙げられ、市場より容易に入手できる。

Examples of the salt represented by formula (I2-a) include salts represented by the following, which can be produced by the method described in JP-A-2012-193170.

Compounds represented by formula (I2-b) include, for example, compounds represented by the following, which are readily available on the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 X ¹ is ^{a salt ( formula} The salt represented by (I3)) is obtained, for example, by reacting a salt represented by formula (I2-a) with carbonyldiimidazole in a solvent, and then further represented by formula (I1-b). It can be produced by reacting with a compound.

(In the formula, all symbols have the same meanings as described above.)
Examples of solvents include chloroform and acetonitrile.
The reaction temperature is generally 5° C. to 80° C., and the reaction time is generally 0.5 hour to 24 hours.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
塩基としては、水酸化カリウム等が挙げられる。
溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 X ¹ is *—O— (where * represents the bonding position with C(R ¹ )(R ² ) or C(Q ¹ )(Q ² )) (in formula (I4) The salt represented by the formula (I2-a) can be produced, for example, by reacting the salt represented by the formula (I2-a) with the compound represented by the formula (I1-b) in the presence of a base in a solvent. can.

(In the formula, all symbols have the same meanings as described above.)
Potassium hydroxide etc. are mentioned as a base.
Examples of solvents include chloroform and acetonitrile.
The reaction temperature is generally 5° C. to 80° C., and the reaction time is generally 0.5 hour to 24 hours.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。
式（Ｉ５－ａ）で表される塩としては、以下で表される塩等が挙げられ、特開２００６－２５７０７８号公報、特開２００９－４６４７９号公報、特開２０１２－１９３１７０号公報に記載された方法で製造することができる。

式（Ｉ５－ｂ）で表される化合物としては、例えば、以下で表される化合物が挙げられ、市場より容易に入手できる。

L ¹ is *-L ² -O-CO-O- (L ² represents a hydrocarbon group having 1 to 33 carbon atoms which may have a substituent, and the -CH _2- may be replaced with -O-, -S-, -CO- or -SO ₂ - * represents the bonding position with X ¹ ) (represented by formula (I5)). A salt represented by formula (I5-a) is, for example, reacted with a salt represented by formula (I5-a) and carbonyldiimidazole in a solvent, and further reacted with a compound represented by formula (I5-b). can do.

(In the formula, all symbols have the same meanings as described above.)
Examples of solvents include chloroform, acetonitrile, and the like.
The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hour to 24 hours.
Examples of the salt represented by the formula (I5-a) include salts represented by the following, described in JP-A-2006-257078, JP-A-2009-46479, and JP-A-2012-193170. It can be manufactured by the method described.

Compounds represented by formula (I5-b) include, for example, compounds represented by the following, which are readily available on the market.

<Acid Generator>
The acid generator of the present invention is an acid generator containing salt (I), and may contain one salt (I) or a combination of two or more salts (I). .
The acid generator of the present invention may contain an acid generator known in the resist field (hereinafter sometimes referred to as "acid generator (B)") in addition to salt (I). The acid generator (B) may be used alone or in combination of two or more.

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, iodonium salts). The anions of the onium salts include sulfonate anions, sulfonylimide anions, sulfonylmethide anions, and the like.

Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. A compound that generates an acid upon exposure to radiation as described in 1. above can be used. Moreover, you may use the compound manufactured by the well-known method. The acid generator (B) may be used in combination of two or more.

［式（Ｂ１）中、
Ｑ^ｂ１及びＱ^ｂ２は、それぞれ独立に、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｌ^ｂ１は、炭素数１～２４の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３～１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ（Ｏ）_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as "acid generator (B1)", provided that the salt (I ) is excluded.).

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

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.
Q ^b1 and Q ^b2 are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably both a fluorine atom.

Examples of the saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. A group formed by combining two or more kinds 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 aliphatic monocyclic cycloalkanediyl groups such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl groups cyclic saturated hydrocarbon group;
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; mentioned.

The group in which —CH ₂ — contained in the saturated hydrocarbon group represented by L ^b1 is replaced with —O— or —CO— is, for example, any one of formulas (b1-1) to (b1-3). The group represented by 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 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 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 hydrocarbon group —CH ₂ — contained in 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 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 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 hydrocarbon group —CH ₂ — contained in 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 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 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 hydrocarbon group —CH ₂ — contained in 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.
Examples of the saturated hydrocarbon group include those similar to the saturated hydrocarbon group for ^Lb1 .

L ^b2 is preferably a single bond.
L ^b3 is preferably a saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a 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 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, and the divalent —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O— or —CO—.

The group in which —CH ₂ — contained in the saturated hydrocarbon group represented by L ^b1 is replaced with —O— or —CO— is a group represented by formula (b1-1) or formula (b1-3) is preferred.

［式（ｂ１－４）中、
Ｌ^ｂ８は、単結合又は炭素数１～２２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。
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の飽和炭化水素基を表す。
Ｌ^ｂ１２は、単結合又は炭素数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の飽和炭化水素基を表す。
Ｌ^ｂ１４は、単結合又は炭素数１～１８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。
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の飽和炭化水素基を表す。
Ｌ^ｂ１８は、単結合又は炭素数１～１７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。
ただし、Ｌ^ｂ１６～Ｌ^ｂ１８の合計炭素数は１９以下である。］ Examples of the group represented by formula (b1-1) include groups represented by formulas (b1-4) to (b1-8).

[In formula (b1-4),
L ^b8 represents a single bond or a 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 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 saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the 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 saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a 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 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 saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a 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 ^b15 represents a single bond or a saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the 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 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 saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the 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 saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a saturated hydrocarbon group having 1 to 19 carbon atoms, more preferably a single bond or a saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a saturated hydrocarbon group having 1 to 18 carbon atoms, more preferably a single bond or a saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b16 is preferably a saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 is preferably a saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b18 is preferably a single bond or a saturated hydrocarbon group having 1 to 17 carbon atoms, more preferably a single bond or a saturated hydrocarbon group having 1 to 4 carbon atoms.

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

[In formula (b1-9),
L ^b19 represents a single bond or a 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 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, a hydroxy group or an alkylcarbonyloxy group. --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 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 saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b23 represents a single bond or a 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, a hydroxy group or an alkylcarbonyloxy group. --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 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 saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b26 represents a single bond or a 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, a hydroxy group or an alkylcarbonyloxy group. --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 substituted 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.

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-4) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-5) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-6) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-7) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-8) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-2) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-9) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-10) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-11) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

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

Ｙ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（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）～式（Ｙ４１）のいずれかで表される基であり、より好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ１６）、式（Ｙ２０）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）又は式（Ｙ４０）で表される基であり、さらに好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ２０）、式（Ｙ３０）、式（Ｙ３９）又は式（Ｙ４０）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）等の、酸素原子を含む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 represented by Y is preferably represented by any one of formulas (Y1) to (Y20), formula (Y30), formula (Y31), formula (Y39) to formula (Y41). more preferably represented by formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y30), formula (Y31), formula (Y39) or formula (Y40) and more preferably a group represented by formula (Y11), formula (Y15), formula (Y20), formula (Y30), formula (Y39) or formula (Y40).
When the alicyclic hydrocarbon group represented by Y is a spiro ring containing an oxygen atom such as formulas (Y28) to (Y35) and formulas (Y39) to (Y40), two oxygen atoms The intervening alkanediyl groups preferably have 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.

Substituents for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms optionally substituted by a hydroxy group, and an alicyclic group having 3 to 16 carbon atoms. hydrocarbon group, alkoxy group having 1 to 12 carbon atoms, aromatic hydrocarbon group having 6 to 18 carbon atoms, aralkyl group having 7 to 21 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, 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, ja represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, and ja represents any integer of 0 to 4). -CH ₂ - contained in an alkyl group having 1 to 16 carbon atoms and an alicyclic hydrocarbon group having 3 to 16 carbon atoms is replaced with -O-, -S(O) ₂ - or -CO- good too. ) and the like.

Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
Examples of alicyclic hydrocarbon groups include cyclopentyl, cyclohexyl, 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 aromatic hydrocarbon group includes aryl groups such as phenyl group, biphenylyl group, naphthyl group and phenanthryl group.
The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group having a chain hydrocarbon group having 1 to 18 carbon atoms (tolyl group , xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and 3 to 18 carbon atoms aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) having an alicyclic hydrocarbon group of
Examples of alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group and nonyl. group, decyl group, undecyl group, dodecyl group and the like.
Alkyl groups substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy and dodecyloxy groups.
The aralkyl group includes benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, naphthylethyl group and the like.
Examples of alkylcarbonyl groups include acetyl group, propionyl group and butyryl group.

Examples of Y include the following.

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

As the sulfonate anion in the salt represented by the formula (B1), formulas (B1-A-1) to (B1-A-10), formulas (B1-A-14) to (B1-A-19) ), and anions represented by formulas (B1-A-24) to (B1-A-55) [hereinafter sometimes referred to as "anion (B1-A-1)" etc. depending on the formula number. ] is preferable, formula (B1-A-1) ~ formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) ~ formula (B1-A-33), formula (B1-A-36) ~ formula (B1-A-40), represented by any of formula (B1-A-47) ~ formula (B1-A-55) Anions are more preferred.

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

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

Preferred sulfonate anions in the salt represented by formula (B1) include anions represented by formulas (B1a-1) to (B1a-34), respectively.

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

Organic cations of Z ⁺ include the same as ZI ⁺ in salt (I).

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

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

When salt (I) and acid generator (B) are contained as acid generators, the ratio of the contents of salt (I) and acid generator (B) (mass ratio; salt (I): acid generator ( B)) is generally 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, still more preferably 10:90 to 90 :10, particularly preferably 15:85 to 85:15.

<Resin Containing Structural Unit Derived from Salt (I)>
The resin of the present invention is a resin (hereinafter sometimes referred to as "resin (A1)") containing a structural unit derived from salt (I) (hereinafter sometimes referred to as "structural unit (I)").
The resin (A1) may be a homopolymer containing one structural unit (I) or a copolymer containing two or more structural units (I).
The content of the structural unit (I) is generally 0.1 to 100 mol%, preferably 0.5 to 50 mol%, more preferably 0.8 to 100 mol%, relative to the total amount of the resin (A1). It is 30 mol %, more preferably 1 to 10 mol %.
As will be described later, the resin (A1) may contain other structural units in addition to the structural unit (I).

<Resist composition>
The resist composition of the present invention contains at least a resin and an acid generator. The resist composition of the present invention may contain resin (A1) or an acid generator containing salt (I). That is, (a) a resin having an acid generator containing salt (I) and a structural unit having an acid-labile group and not containing structural unit (I) (hereinafter sometimes referred to as "resin (A2)") ), (b) a composition containing an acid generator containing salt (I) and resin (A1), (c) a composition containing resin (A1), or (d) a salt ( It is a composition containing an acid generator not containing I) and a resin (A1). The resist composition of the present invention is preferably a resist composition containing at least resin (A1). In this case, two or more resins (A1) may be included.

In particular, the resist composition of the present invention preferably contains salt (I) as an acid generator regardless of whether the resin contains structural unit (I). and (b) are preferred. Compositions (c) and (d) preferably further contain an acid generator (B).
Here, the term "acid-labile group" refers to a structure having a leaving group, the leaving group being eliminated by contact with an acid, and a constitutional unit having a hydrophilic group (e.g., a hydroxy group or a carboxy group). means a group that converts to units.
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)").

<Acid generator>
The resist composition of the present invention contains the acid generator described above. The content of the acid generator is preferably 1 part by mass or more and 40 parts by mass or less, more preferably 3 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the resin (A) described later.

<Resin>
In addition to the structural unit (I), the resin (A1) preferably has a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"), and the structural unit (a1) It may contain other structural units. Structural units other than the structural unit (a1) include a structural unit having no halogen atom and no acid labile group (hereinafter sometimes referred to as "structural unit (s)"), structural unit (a1), and Structural units other than the structural unit (s) (for example, the structural unit (a4) having a halogen atom, the structural unit (a5) having a non-leaving hydrocarbon group, the structural unit (a6) having a carboxyl group, the structural unit (a6) having a carboxyl group, the a structural unit (II)) that generates an acid with a phenyl group, and other structural units derived from monomers known in the art.
The resin (A2) does not contain the structural unit (I), and preferably has a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"), and the structural unit (a1) It may contain other structural units.
The resin having the structural unit (a1), that is, the resin (A1) and the resin (A2) are collectively referred to as the resin (A).

［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３～２０の脂環式炭化水素基又はこれらを組み合わせた基を表すか、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。
＊は結合手を表す。］

［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。
＊は結合手を表す。］ <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 (A) 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 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof; Alternatively, R ^a1 and R ^a2 are bonded to each other to form a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
ma and na each independently represent 0 or 1, and at least one of ma and na represents 1;
* represents a bond. ]

[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 bond. ]

アルキル基と脂環式炭化水素基とを組み合わせた基としては、例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、シクロヘキシルメチル基、アダマンチルメチル基、アダマンチルジメチル基、ノルボルニルエチル基等が挙げられる。
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－との結合手を表す。

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 alicyclic hydrocarbon groups for R ^a1 , R ^a2 and R ^a3 may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl groups. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bonding site). The alicyclic hydrocarbon groups of R ^a1 , R ^a2 and R ^a3 preferably have 3 to 16 carbon atoms.

Groups in which an alkyl group and an alicyclic hydrocarbon group are combined include, for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl An ethyl group etc. are mentioned.
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 bond 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, groups formed by combining these groups, and the like.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same groups as those listed for R ^a1 , R ^a2 and R ^a3 .
The aromatic hydrocarbon group includes aryl groups such as phenyl group, biphenylyl group and naphthyl group.
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 the aforementioned alkyl group and an alicyclic hydrocarbon group (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methyl phenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), alicyclic hydrocarbon groups aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cyclohexyl groups such as phenylcyclohexyl group, and the like.
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 ^a3′ )—X—R ^a2 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 bond.

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

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. The resolution of a positive resist pattern can be improved by using a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group in a positive resist composition. can be done.

［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－との結合手を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組み合わせた基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１８の脂環式炭化水素基又はこれらを組合せ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。］ The structural unit derived from a (meth)acrylic monomer having group (1) is preferably a structural unit represented by formula (a1-0) (hereinafter sometimes referred to as structural unit (a1-0).) , a structural unit represented by formula (a1-1) (hereinafter sometimes referred to as structural unit (a1-1)) or a structural unit represented by formula (a1-2) (hereinafter, structural unit (a1- 2) may be mentioned). 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 a bond with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents any integer from 0 to 14;
n1 represents any integer from 0 to 10;
n1' represents an integer of 0 to 3; ]

R ^a01 , R ^a4 and R ^a5 are preferably methyl groups.
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.
The alkyl groups, alicyclic hydrocarbon groups and groups in which these are combined for R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 are the same as the groups listed for R ^a1 to R ^a3 in formula (1). groups.
The alkyl group in R ^a02 , R ^a03 and R ^a04 preferably has 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, still more preferably a methyl group.
The alkyl group in R ^a6 and R ^a7 preferably has 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group or an isopropyl group, still more preferably an ethyl group or an isopropyl group.
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.
It is preferable that the combined group of an alkyl group and an alicyclic hydrocarbon group have a total carbon number of 18 or less.
R ^a02 and R ^a03 are preferably alkyl groups having 1 to 6 carbon atoms, more preferably methyl or ethyl groups.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.
R ^a6 and R ^a7 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group or an isopropyl group, still more preferably an ethyl group or an isopropyl group.
m1 is preferably an integer from 0 to 3, more preferably 0 or 1.
n1 is preferably an integer from 0 to 3, more preferably 0 or 1.
n1' is preferably 0 or 1.

As the structural unit (a1-0), for example, a structural unit represented by any one of formulas (a1-0-1) to (a1-0-12) and R ^a01 in the structural unit (a1-0) Structural units in which the corresponding methyl group is replaced with a hydrogen atom are exemplified, and structural units represented by any one of formulas (a1-0-1) to (a1-0-10) are 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 (a1-1-4) and a methyl group corresponding to R ^a4 in structural unit (a1-1) is replaced with a hydrogen atom. Structural units are preferred, and structural units represented by any one of formulas (a1-1-1) to (a1-1-4) are more preferred.

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

When the resin (A) contains the structural unit (a1-0) and/or the structural unit (a1-1) and/or the structural unit (a1-2), the total content of these is the total structure of the resin (A) It is usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, still more preferably 25 to 70 mol%, still more preferably 30 to 65 mol %.

［式（ａ１－４）中、
Ｒ^a32は、水素原子、ハロゲン原子、又は、ハロゲン原子を有していてもよい炭素数１～６のアルキル基を表す。
Ｒ^a33は、ハロゲン原子、ヒドロキシ基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数２～４のアルキルカルボニル基、炭素数２～４のアルキルカルボニルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
ｌａは０～４のいずれかの整数を表す。ｌａが２以上である場合、複数のＲ^a33は互いに同一であっても異なってもよい。
Ｒ^a34及びＲ^a35はそれぞれ独立に、水素原子又は炭素数１～１２の炭化水素基を表し、Ｒ^a36は、炭素数１～２０の炭化水素基を表すか、Ｒ^a35及びＲ^a36は互いに結合してそれらが結合する－Ｃ－Ｏ－とともに炭素数２～２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。］ 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 the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl It represents an oxy group or a methacryloyloxy group.
la represents an integer of 0 to 4; When la is 2 or more, a plurality of R ^a33 may be the same or different.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^a35 and R ^a36 are bonded to each other to form a C2-C20 divalent hydrocarbon group together with -C-O- to which they are bonded, and -CH ₂ - contained in the hydrocarbon group and the divalent hydrocarbon group is - O- or -S- may be substituted. ]

Examples of alkyl groups for R ^a32 and R ^a33 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group and hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, even more preferably a methyl group.
Halogen atoms in R ^a32 and R ^a33 include fluorine, chlorine and bromine atoms.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1 , 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, etc. is mentioned.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy and hexyloxy groups. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is even more preferable.
Alkylcarbonyl groups include acetyl, propionyl and butyryl groups.
An acetyloxy group, a propionyloxy group, a butyryloxy group, etc. are mentioned as an alkylcarbonyloxy group.
Hydrocarbon groups for R ^a34 , R ^a35 and R ^a36 include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups in which these are combined. Examples include the same alkyl groups and alicyclic hydrocarbon groups as R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 .
The aromatic hydrocarbon group includes aryl groups such as phenyl group, biphenylyl group, naphthyl group and phenanthryl group.
The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group having a chain hydrocarbon group having 1 to 18 carbon atoms (tolyl group , xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and 3 to 18 carbon atoms aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) having an alicyclic hydrocarbon group of
Examples of the combined group include groups obtained by combining the aforementioned alkyl groups and alicyclic hydrocarbon groups (eg, cycloalkylalkyl groups), aralkyl groups such as benzyl groups, aryl-cyclohexyl groups such as phenylcyclohexyl groups, 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. is mentioned.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and still more preferably a methoxy group.
la is preferably 0 or 1, more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group, more preferably a methyl group or an ethyl group.
The hydrocarbon group of R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination of these A group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic 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 having 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.

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 (a1-4-12) and structures in which the hydrogen atom corresponding to R ^a32 in the structural unit (a1-4) is replaced with a methyl group units, more preferably structural units represented by formulas (a1-4-1) to (a1-4-5) and formula (a1-4-10).

When the resin (A) contains the structural unit (a1-4), the content thereof is preferably 10 to 95 mol%, preferably 15 to 90 mol%, based on the total of all structural units of the resin (A). It is more preferably 20 to 85 mol %, even more preferably 20 to 70 mol %, and particularly preferably 20 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との結合手を表す。
Ｌ⁵¹、Ｌ⁵²、Ｌ⁵³及びＬ⁵⁴は、それぞれ独立に、－Ｏ－又は－Ｓ－を表す。
ｓ１は、１～３のいずれかの整数を表す。
ｓ１’は、０～３のいずれかの整数を表す。 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 bond with L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent -O- or -S-.
s1 represents any integer from 1 to 3;
s1′ represents any integer from 0 to 3;

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

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

When the resin (A) 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 (A). , more preferably 5 to 40 mol %, and even more preferably 5 to 30 mol %.

［式（ａ１－０Ｘ）中、
Ｒ^ｘ１は、水素原子又はメチル基を表す。
Ｒ^ｘ２及びＲ^ｘ３は、それぞれ独立に、炭素数１～６の飽和炭化水素基を表す。
Ａｒ^ｘ１は、炭素数６～３６の芳香族炭化水素基を表す。］ Examples of the structural unit (a1) include structural units represented by formula (a1-0X) (hereinafter sometimes referred to as structural unit (a1-0X)).

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

Saturated hydrocarbon groups for R ^x2 and R ^x3 include alkyl groups, saturated alicyclic hydrocarbon groups, and groups formed by combinations thereof.
Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl and hexyl groups.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic saturated alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and the like. . Examples of polycyclic alicyclic saturated hydrocarbon groups include an adamantyl group and a norbornyl group.

The aromatic hydrocarbon group for Ar ^x1 includes aryl groups having 6 to 36 carbon atoms such as phenyl group, naphthyl group and anthryl group.

Ar ^x1 is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, more preferably a phenyl group or a naphthyl group, still more preferably a phenyl group.
R ^x1 , R ^x2 and R ^x3 are each independently preferably a methyl group or an ethyl group, more preferably a methyl group.

Examples of the structural unit (a1-0X) include structural units described below and structural units in which a methyl group corresponding to R ^x1 in the structural unit (a1-0X) is replaced with a hydrogen atom. Structural unit (a1-0X) is preferably structural unit (a1-0X-1) to structural unit (a1-0X-3).

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

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

When the resin (A) contains structural units such as the above formulas (a1-3-1) to (a1-3-7), the content is 5 ~60 mol% is preferred, 5 to 50 mol% is more preferred, and 10 to 40 mol% is even more preferred.

In addition to the structural unit (I) and the structural unit (a1), the resin (A) further includes a structural unit having no acid-labile group (hereinafter sometimes referred to as "structural unit (s)") and other structures. Examples include units (hereinafter sometimes referred to as “structural unit (t)”) and structural units derived from monomers known in the art.

<Structural unit (s)>
As a monomer leading to the structural unit (s), a monomer having no acid-labile group known in the field of resists can be used.
The structural unit (s) preferably has a hydroxy group or a lactone ring. A structural unit having a hydroxy group and no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and/or a structure having a lactone ring and no acid-labile group When a resin having a unit (hereinafter sometimes referred to as "structural unit (a3)") is used in the positive resist composition of the present invention, the resolution of the positive 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 positive resist pattern from the positive 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 As (a2), it is preferable to use a structural unit (a2) having a phenolic hydroxy group. When using an ArF excimer laser (193 nm) or the like, the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, and more preferably a structural unit (a2-1) described later. preferable. As the structural unit (a2), one type may be contained alone, or two or more types may be contained.

［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２～４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手を表す。
Ａ^a52は、それぞれ独立に、炭素数１～６のアルカンジイル基を表す。
Ｘ^a51及びＸ^a52は、それぞれ独立に、－Ｏ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ｎｂは、０又は１を表す。
ｍｂは０～４のいずれかの整数を表す。ｍｂが２以上のいずれかの整数である場合、複数のＲ^a51は互いに同一であっても異なってもよい。］ Structural units having a phenolic hydroxy group in structural units (a2) include structural units represented by formula (a2-A) (hereinafter sometimes referred to as “structural unit (a2-A)”).

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

Halogen atoms in R ^a50 include fluorine, chlorine and bromine atoms.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom for R ^a50 include 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.
Alkoxy groups for R ^a51 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy and tert-butoxy groups. An alkoxy group having 1 to 4 carbon atoms is preferred, a methoxy group or an ethoxy group is more preferred, and a methoxy group is even more preferred.
The alkylcarbonyl group for R ^a51 includes an acetyl group, a propionyl group and a butyryl group.
The alkylcarbonyloxy group for R ^a51 includes an acetyloxy group, a propionyloxy group and a butyryloxy group.
R ^a51 is preferably a methyl group.

^* -X ^a51 -(A ^a52 -X ^a52 ) _nb - are: ^* -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 includes methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane- 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2 -methylbutane-1,4-diyl group and the like.
A ^a52 is preferably a methylene group or an ethylene group.

A ^a50 is preferably a single bond, ^* -CO-O- or ^* -CO-O-A ^a52 -CO-O-, a single bond, ^* -CO-O- or ^* -CO-O-CH ₂ --CO--O-- is more preferred, and a single bond or ^* --CO--O-- is even more preferred.

mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.
The hydroxy group is preferably bonded to the o-position or p-position of the benzene ring, more preferably bonded to the p-position.

Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577.

The structural unit (a2-A) includes structural units represented by formulas (a2-2-1) to (a2-2-4) and formulas (a2-2-1) to (a2-2- Examples of the structural unit represented by 4) include a structural unit in which the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom. Structural unit (a2-A) includes a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), and a structural unit represented by formula (a2-2-6). and the structural unit represented by formula (a2-2-1), the structural unit represented by formula (a2-2-3) or the structural unit represented by formula (a2-2-6), A structural unit in which the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom is preferred.

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

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

In formula (a2-1),
L ^a3 represents —O— or ^* —O—(CH ₂ ) _k2 —CO—O—;
k2 represents any integer from 1 to 7; * represents a bond 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 an integer from 0 to 10;

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

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

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

<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手を表す。
Ｒ^ａ１８、Ｒ^ａ１９及びＲ^ａ２０は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ２４は、ハロゲン原子を有していてもよい炭素数１～６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^ａ２１は炭素数１～４の脂肪族炭化水素基を表す。
Ｘ^ａ３は、－ＣＨ_２－又は酸素原子を表す。
Ｒ^ａ２２、Ｒ^ａ２３及びＲ^ａ２５は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１～４の脂肪族炭化水素基を表す。
ｐ１は０～５のいずれかの整数を表す。
ｑ１は、０～３のいずれかの整数を表す。
ｒ１は、０～３のいずれかの整数を表す。
ｗ１は、０～８のいずれかの整数を表す。
ｐ１、ｑ１、ｒ１及び／又はｗ１が２以上のとき、複数のＲ^ａ２１、Ｒ^ａ２２、Ｒ^ａ２３及び／又はＲ^ａ２５は互いに同一であってもよく、異なっていてもよい。］ Structural unit (a3) 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 bond with a carbonyl group.
R ^a18 , R ^a19 and R ^a20 each independently represent a hydrogen atom or a methyl group.
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
X ^a3 represents —CH ₂ — or an oxygen atom.
R ^a22 , R ^a23 and R ^a25 each independently represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents any integer from 0 to 5;
q1 represents an integer of 0 to 3;
r1 represents an integer of 0 to 3;
w1 represents any integer from 0 to 8;
When p1, q1, r1 and/or w1 are 2 or more, a plurality of R ^a21 , R ^a22 , R ^a23 and/or R ^a25 may be the same or different. ]

Examples of the aliphatic hydrocarbon group for R ^a21 , R ^a22 , R ^a23 and R ^a25 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group and tert-butyl group. be done.
Halogen atoms in R ^a24 include fluorine, chlorine, bromine and iodine atoms.
Examples of the alkyl group for R ^a24 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group, preferably having 1 to 4 carbon atoms. and more preferably a methyl group or an ethyl group.
The alkyl group having a halogen atom for R ^a24 includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluoro A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group and the like are included.

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 ^a18 , R ^a19 , R ^a20 and R ^a24 in formulas (a3-4) are preferably structural units in which methyl groups are replaced with hydrogen atoms.

When the resin (A) contains the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on the total structural units of the resin (A). , more preferably 10 to 60 mol %.
Further, the content of structural unit (a3-1), structural unit (a3-2), structural unit (a3-3) or structural unit (a3-4) is is preferably 5 to 60 mol %, more preferably 5 to 50 mol %, 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のフッ素原子を有する飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯに置き換わっていてもよい。］
Ｒ⁴²で表される飽和炭化水素基は、鎖式炭化水素基及び単環又は多環の脂環式炭化水素基、並びに、これらを組み合わせることにより形成される基等が挙げられる。 <Structural unit (a4)>
Structural units (a4) include the following structural units.

[In formula (a4),
R ⁴¹ represents a hydrogen atom or a methyl group.
R ⁴² represents a saturated hydrocarbon group having 1 to 24 fluorine atoms, and --CH ₂ -- contained in the saturated hydrocarbon group may be replaced with --O-- or --CO. ]
Examples of saturated hydrocarbon groups represented by R ⁴² include chain hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these groups.

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。 Chain hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl groups. mentioned. Monocyclic or polycyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl; decahydronaphthyl, adamantyl, norbornyl and the following groups (* represents a bond) and other polycyclic alicyclic hydrocarbon groups.

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

［式（ａ４－０）中、
Ｒ^５４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。
Ｒ^６は、水素原子又はフッ素原子を表す。］ The structural unit (a4) is at least selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3) and formula (a4-4) Structural units represented by one are exemplified.

[In the formula (a4-0),
^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.
^R6 represents a hydrogen atom or a fluorine atom. ]

The alkanediyl group having 1 to 4 carbon atoms in L ^4a includes linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, ethane-1 ,1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group, etc. alkanediyl groups.

The perfluoroalkanediyl group for L ^3a includes a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane group. -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。〕
＊は結合手であり、右側の＊が－Ｏ－ＣＯ－Ｒ^a42との結合手を表す。］

[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 the 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 bond, and * on the right side represents a bond with —O—CO—R ^a42 . ]

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

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。 Chain hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl groups. mentioned. Monocyclic or polycyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl; decahydronaphthyl, adamantyl, norbornyl and the following groups (* represents a bond) and other polycyclic alicyclic hydrocarbon groups.

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

［式（ａ－ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＲ^a42との結合手を表す。）。
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。
＊は結合手を表す。］
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 the substituent that R ^a42 may have 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-- (* represents a bond with R ^a42 ).
A ^a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
* represents a bond. ]
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.

The saturated hydrocarbon groups for A ^a45 include 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, cyclooctyl group; and decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bond ) and other polycyclic alicyclic hydrocarbon groups.

R ^a42 is preferably a saturated hydrocarbon group optionally having a halogen atom, more preferably an alkyl group having a halogen atom and/or a saturated hydrocarbon group having a group represented by formula (a-g3).
When R ^a42 is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably having 1 to 1 carbon atoms. A perfluoroalkyl group having 6 carbon atoms, particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Perfluoroalkyl groups include perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl and perfluorooctyl groups. A perfluorocyclohexyl group etc. are mentioned as a perfluorocycloalkyl group.
When R ^a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), the total carbon number of R ^a42 including the number of carbon atoms contained in the group represented by formula (a-g3) The number is preferably 15 or less, more preferably 12 or less. When it has a group represented by formula (a-g3) as a substituent, the number thereof is preferably one.

［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との結合手を表す。）。
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手を表す。］ When R ^a42 is a saturated hydrocarbon 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 bond 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 bond 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 (* represents a bond 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, hexane-1,6-diyl group straight-chain alkanediyl groups such as; Branched alkanediyl groups such as 2-methylbutane-1,4-diyl group can be mentioned.
Examples of substituents on the alkanediyl group represented by A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and still more preferably an ethylene group.

The divalent saturated hydrocarbon groups represented by A ^a42 , A ^a43 and A ^a44 in the group represented by the formula (a-g1) include linear or branched alkanediyl groups and monocyclic divalent alicyclic A saturated hydrocarbon group, a divalent saturated hydrocarbon group formed by combining an alkanediyl group and a divalent saturated alicyclic 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 bond, and ** represents a bond with --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。］ As the structural unit represented by formula (a4-1), a structural unit represented by formula (a4-2) is preferable.

[In formula (a4-2),
R ^f5 represents a hydrogen atom or a methyl group.
L ⁴⁴ represents an alkanediyl group having 1 to 6 carbon atoms, and --CH ₂ -- contained in the alkanediyl group may be replaced with --O-- or --CO--.
R ^f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and a fluorine atom.
However, the upper limit of the total carbon number of L ⁴⁴ and R ^f6 is 21. ]

Examples of the 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 ^a42 .
The alkanediyl group having 1 to 6 carbon atoms in L ⁴⁴ is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.

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

［式（ａ４－３）中、
Ｒ^f7は、水素原子又はメチル基を表す。
Ｌ⁵は、炭素数１～６のアルカンジイル基を表す。
Ａ^f13は、フッ素原子を有していてもよい炭素数１～１８の２価の飽和炭化水素基を表す。
Ｘ^f12は、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＡ^f13との結合手を表す。）。
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。］

[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 bond 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 ^Aa41 .

The divalent saturated hydrocarbon group optionally having a fluorine atom in A ^f13 may have a divalent aliphatic saturated hydrocarbon group optionally having a fluorine atom and a fluorine atom divalent alicyclic saturated hydrocarbon groups, preferably divalent aliphatic hydrocarbon groups optionally having fluorine atoms, more preferably alkanes optionally having fluorine atoms It is a diyl group, more preferably a perfluoroalkanediyl group.
Divalent aliphatic saturated hydrocarbon groups 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, pentyl, hexyl, perfluorohexyl, heptyl, perfluoroheptyl, octyl and perfluorooctyl groups Alkyl group, cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, perfluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group, norbornylmethyl group, perfluoroadamantyl group , a perfluoroadamantylmethyl group, and the like.

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

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

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

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

The saturated hydrocarbon group represented by R ^{f22 includes the same saturated hydrocarbon group represented by R a42 .} R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom. An alkyl group having 1 to 6 carbon atoms and having a fluorine atom is more preferred.

In formula (a4-4), A ^f21 is preferably --(CH ₂ ) _j1 --, more preferably an ethylene group or a methylene group, and still more preferably a methylene group.

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

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

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

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

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 saturated chain 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. The polycyclic divalent alicyclic saturated hydrocarbon group includes 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との結合手を表す。）。
Ｌ^x1は、炭素数１～１６の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x2は、単結合又は炭素数１～１５の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x1及びＬ^x2の合計炭素数は、１６以下である。
式（Ｌ１－２）中、
Ｌ^x3は、炭素数１～１７の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x4は、単結合又は炭素数１～１６の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x3及びＬ^x4の合計炭素数は、１７以下である。
式（Ｌ１－３）中、
Ｌ^x5は、炭素数１～１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x6及びＬ^x7は、それぞれ独立に、単結合又は炭素数１～１４の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x5、Ｌ^x6及びＬ^x7の合計炭素数は、１５以下である。
式（Ｌ１－４）中、
Ｌ^x8及びＬ^x9は、単結合又は炭素数１～１２の２価の脂肪族飽和炭化水素基を表す。
Ｗ^x1は、炭素数３～１５の２価の脂環式飽和炭化水素基を表す。
ただし、Ｌ^x8、Ｌ^x9及びＷ^x1の合計炭素数は、１５以下である。
Ｌ^x1は、好ましくは、炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、メチレン基又はエチレン基である。
Ｌ^x2は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、単結合である。
Ｌ^x3は、好ましくは、炭素数１～８の２価の脂肪族飽和炭化水素基である。
Ｌ^x4は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基である。
Ｌ^x5は、好ましくは、炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、メチレン基又はエチレン基である。
Ｌ^x6は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、メチレン基又はエチレン基である。
Ｌ^x7は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基である。
Ｌ^x8は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、単結合又はメチレン基である。
Ｌ^x9は、好ましくは、単結合又は炭素数１～８の２価の脂肪族飽和炭化水素基、より好ましくは、単結合又はメチレン基である。
Ｗ^x1は、好ましくは、炭素数３～１０の２価の脂環式飽和炭化水素基、より好ましくは、シクロヘキサンジイル基又はアダマンタンジイル基である。 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 formula below, * and ** represent a binding site, and * represents a bond with an oxygen atom.

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

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

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

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

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（Ａ）が、構造単位（ａ５）を有する場合、その含有率は、樹脂（Ａ）の全構造単位に対して、１～３０モル％が好ましく、２～２０モル％がより好ましく、３～１５モル％がさらに好ましい。 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 (A) has the structural unit (a5), the content thereof is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, based on the total structural units of the resin (A), and 3 ~15 mol% is more preferred.

<Structural unit (II)>
The resin (A) may further contain a structural unit that is decomposed by exposure to generate an acid (hereinafter sometimes referred to as "structural unit (II)"). includes structural units described in JP-A-2016-79235, a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or a structural unit having a sulfonio group and an organic anion in the side chain. Preferably.

［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 and optionally having a halogen atom represented by R ^III3 includes an alkyl group having 1 to 6 carbon atoms and optionally having a halogen atom represented by R ^a8 . The same can be mentioned.
The alkanediyl group having 1 to 8 carbon atoms represented by A ^x1 includes methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group and pentane-1,5-diyl group. , hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2, 4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. mentioned.
The perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted on 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 , pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group and other branched alkanediyl groups; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 ,4-diyl group, cycloalkanediyl group such as cyclooctane-1,5-diyl group; norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane Divalent polycyclic alicyclic saturated hydrocarbon groups such as -2,6-diyl group and the like can be mentioned.

Examples of saturated hydrocarbon groups in which —CH ₂ — is replaced with —O—, —S— or —CO— include divalent groups represented by formulas (X1) to (X53). mentioned. However, -CH ₂ - contained in the saturated hydrocarbon group has 17 or less carbon atoms before being replaced with -O-, -S- or -CO-. In the following formula, * represents a bond with A ^x1 .

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

Organic cations represented by ZA ⁺ include the same as ZI ⁺ in the salt represented by formula (I).

［式（ＩＩ－２－Ａ）中、Ｒ^ＩＩＩ３、Ｘ^ＩＩＩ３及びＺＡ^＋は、上記と同じ意味を表す。
ｚ２Ａは、０～６のいずれかの整数を表す。
Ｒ^ＩＩＩ２及びＲ^ＩＩＩ４は、それぞれ独立して、水素原子、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表し、ｚが２以上のとき、複数のＲ^ＩＩＩ２及びＲ^ＩＩＩ４は互いに同一であってもよいし、異なっていてもよい。
Ｑ^ａ及びＱ^ｂは、それぞれ独立して、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。］ The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A).

[In formula (II-2-A), R ^III3 , X ^III3 and ZA ⁺ have the same meanings as above.
z2A represents an integer of 0-6.
R ^III2 and R ^III4 each independently represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms, and when z is 2 or more, a plurality of R ^III2 and R ^III4 are the same may be different.
Q ^a and Q ^b each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group. ]

Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by R ^III2 , R ^III4 , Q ^a and Q ^b include the same perfluoroalkyl group having 1 to 6 carbon atoms as the substituent of A ^x1 described above. be done.

［式（ＩＩ－２－Ａ－１）中、
Ｒ^ＩＩＩ２、Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ４、Ｑ^a、Ｑ^b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。
ｚ２Ａ１は、０～６のいずれかの整数を表す。
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 and ZA ⁺ have the same meanings as above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
z2A1 represents an integer of 0-6.
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 more preferable.

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

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

［式（ＩＩ－１－１）中、
Ａ^ＩＩ１は、単結合又は２価の連結基を表す。
Ｒ^ＩＩ１は、炭素数６～１８の２価の芳香族炭化水素基を表す。
Ｒ^ＩＩ２及びＲ^ＩＩ３は、それぞれ独立に、炭素数１～３０の鎖式炭化水素基、炭素数３～３６の脂環式炭化水素基又は炭素数６～３６の芳香族炭化水素基を表し、該鎖式炭化水素基に含まれる水素原子は、ヒドロキシ基、炭素数１～１２のアルコキシ基、炭素数３～１２の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基で置換されていてもよく、該脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、炭素数１～１８の脂肪族炭化水素基、炭素数２～４のアルキルカルボニル基又はグリシジルオキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基又は炭素数１～１２のアルコキシ基で置換されていてもよい。
Ｒ^ＩＩ２とＲ^ＩＩ３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^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。］ 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 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 hydrogen atoms contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^II2 and R ^II3 may combine with 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 ^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. ]

The divalent linking group represented by A ^II1 includes, for example, a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is -O-, -S- or -CO- may be substituted. Specific examples thereof include the same divalent saturated hydrocarbon groups having 1 to 18 carbon atoms represented by X ^III3 .
Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ^II1 include a phenylene group and a naphthylene group.
Chain hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, alkoxy groups, alicyclic hydrocarbon groups, and aromatic substituents of chain hydrocarbon groups represented by R ^II2 and R ^II3 A hydrocarbon group, a halogen atom as a substituent of an alicyclic hydrocarbon group, an aliphatic hydrocarbon group, an alkylcarbonyl group, a halogen atom as a substituent of an aromatic hydrocarbon group, and an alkoxy group are represented by the above-described formula (b2 The same as R ^b4 to R ^b6 in -1) can be mentioned.
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.

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

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

Sulfonylimide anions represented by A ⁻ include the following.

Sulfonylmethide anions include the following.

Carboxylate anions include the following.

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

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

Resin (A) may have structural units other than the structural units described above, and examples of such structural units include structural units well known in the art.

The resin (A1) is preferably a resin comprising the structural unit (I) and the structural unit (a1) or a resin comprising the structural unit (I), the structural unit (a1) and the structural unit (s), more preferably is a resin composed of a structural unit (I) and a structural unit (a1).
The resin (A2) is preferably a resin comprising the structural unit (a1) or a resin comprising the structural unit (a1) and the structural unit (s), more preferably a resin comprising the structural unit (a1).

Structural unit (a1) is preferably structural unit (a1-0), structural unit (a1-0X), structural unit (a1-1) and structural unit (a1-2) (preferably cyclohexyl group, and cyclopentyl group Structural unit having structural unit), more preferably structural unit (a1-0), structural unit (a1-0X), structural unit (a1-1) and structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group).
Structural unit (s) is preferably at least one selected from the group consisting of structural unit (a2) and structural unit (a3). Structural unit (a2) is preferably 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 (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (e.g., radical polymerization method) using a monomer that leads to these structural units. be able to. The content of each structural unit in the resin (A) can be adjusted by adjusting the amount of monomer used for polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, further preferably 15,000 or less).
As used herein, the weight average molecular weight is a value determined by gel permeation chromatography. Gel permeation chromatography can be measured under the analysis conditions described in Examples.

<Resins other than resin (A)>
The positive resist composition of the present invention may contain a resin other than resin (A). A resin other than the resin (A) is a resin that does not contain the structural unit (a1). Examples of such a resin include a resin that consists only of the structural unit (a4), and a resin that contains the structural unit (a4) and the structural unit. (a5) (hereinafter, a resin consisting only of the structural unit (a4) and a resin consisting of the structural unit (a4) and the structural unit (a5) may be collectively referred to as a resin (X)), etc. mentioned.
In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, based on the total of all structural units of the resin (X). , more preferably 45 mol % or more. Structural units other than this can be appropriately adjusted in the same range as that included in the resin (A) or according to these ranges.
Also, the range of each structural unit contained in the resin (A2) can be adjusted as appropriate in the same manner as the range contained in the resin (A) or according to these ranges.
Each structural unit that constitutes the resin (X) may be used alone or in combination of two or more. Using a monomer that induces these structural units, the resin (X) is produced by a known polymerization method (e.g., radical polymerization method). can do. The content of each structural unit in the resin (X) can be adjusted by adjusting the amount of the monomer used for polymerization.
The weight average molecular weights of resin (X) are each independently preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of resin (X) is the same as in the case of resin (A).
Further, when the positive resist composition contains the resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass with respect to 100 parts by mass of the resin (A). , more preferably 1 to 40 parts by mass, particularly preferably 1 to 30 parts by mass, particularly preferably 1 to 8 parts by mass.

The content of the resin (A) in the positive resist composition of the present invention is preferably 80% by mass or more and 99% by mass or less with respect to the solid content of the positive resist composition, and 90 to 99% by mass. more preferred. When a resin other than the resin (A) is contained, the total content of the resin (A) and the resin other than the resin (A) is 80% by mass or more and 99% by mass with respect to the solid content of the positive resist composition. % by mass or less, and more preferably 90 to 99% by mass. The solid content and resin content of the positive resist composition can be measured by known analytical means such as liquid chromatography or gas chromatography.

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

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

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

レジスト組成物がクエンチャー（Ｃ）を含有する場合、クエンチャー（Ｃ）の含有率は、レジスト組成物の固形分中、通常、０．０１～５質量％であり、好ましくは０．０１～３質量％である。 The weak acid inner salt (D) includes the following salts.

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

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

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

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) a step of applying the resist composition of the present invention onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) heating the exposed composition layer; and (5) developing the heated composition layer.

The coating of the resist composition on the substrate can be carried out using a commonly used device such as a spin coater. Examples of substrates include inorganic substrates such as silicon wafers. Before applying the resist composition, the substrate may be washed, and an antireflection film or the like may be formed on the substrate.
By drying the applied composition, the solvent is removed and a composition layer is formed. Drying is carried out, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a decompression device. The heating temperature is preferably 50 to 200° C., and the heating time is preferably 10 to 180 seconds. Moreover, the pressure for drying under reduced pressure is preferably about 1 to 1.0×10 ⁵ Pa.
The resulting composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As the exposure light source, a KrF excimer laser (wavelength: 248 nm), an ArF excimer laser (wavelength: 193 nm), an F2 excimer laser ₍ wavelength: 157 nm) that emits a laser beam in the ultraviolet region, a solid-state laser source (YAG or semiconductor laser etc.) and emits harmonic laser light in the far ultraviolet region or vacuum ultraviolet region by wavelength conversion, electron beam, and extreme ultraviolet light (EUV). can be done. In the present specification, these irradiations with radiation may be collectively referred to as "exposure". During exposure, exposure is usually performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.
The exposed composition layer is subjected to a heat treatment (so-called post-exposure bake) in order to promote the deprotection reaction at the acid-labile groups. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C.
The composition layer after heating is usually developed using a developer using a developing device. The developing method includes a dipping method, a paddle method, a spraying method, a dynamic dispensing method, and the like. The development temperature is preferably, for example, 5 to 60° C., and the development time is preferably, for example, 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.
When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. Examples thereof include aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline). The alkaline developer may contain a surfactant.
After development, the resist pattern is preferably washed with ultrapure water, and then water remaining on the substrate and pattern is removed.
When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as "organic developer") is used as the developer.
Examples of organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether. ether solvents; amide solvents such as N,N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole;
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably substantially only the organic solvent.
Among them, as the organic developer, a developer containing butyl acetate and/or 2-heptanone is preferable. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially contains butyl acetate and/or 2-heptanone. - more preferably only heptanone.
The organic developer may contain a surfactant. In addition, the organic developer may contain a trace amount of water.
During development, the development may be stopped by replacing the organic developer with a solvent of a different type.
It is preferable to wash the resist pattern after development with a rinsing liquid. The rinse liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent.
After cleaning, it is preferable to remove the rinse liquid remaining on the substrate and pattern.

<Application>
The resist composition of the present invention is 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.
A weight average molecular weight is the value calculated|required by the gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
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)
The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent Model 1100, MASS: Agilent Model LC/MSD). In the following examples, the value of this molecular ion peak is indicated by "MASS".

式（Ｉ－１－ａ）で表される化合物２５部、式（Ｉ－１－ｃ）で表される塩４．６１部及びクロロホルム１００部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、式（Ｉ－１－ｂ）で表される化合物１９．８６部を添加し、２３℃で２時間攪拌した。得られた反応混合物に、クロロホルム１８０部及び１０％炭酸カリウム水溶液１５５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水６０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を４回繰り返した。得られた有機層を濃縮し、濃縮混合物をカラムクロマトグラフィー（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝５／１）により分取することにより、式（Ｉ－１－ｄ）で表される化合物３８．８９部を得た。

式（Ｉ－１－ｄ）で表される化合物３８．８６部及びアセトニトリル２００部を混合し、２３℃で３０分間攪拌した後、５℃まで冷却した。得られた混合溶液に、水素化ホウ素ナトリウム３．５３部及びイオン交換水５２．９５部の混合溶液を添加し、２３℃で１８時間攪拌した。得られた反応混合物を濃縮した後、濃縮残に、ｔｅｒｔ－ブチルメチルエーテル２３０部及びイオン交換水９０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水９０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮混合物をカラムクロマトグラフィー（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝２／１）により分取することにより、式（Ｉ－１－ｅ）で表される化合物３６．９３部を得た。

式（Ｉ－１－ｅ）で表される化合物３６．９３部、ピリジン３０．５６部、ジメチルアミノピリジン８．５８部及びメチルイソブチルケトン１８０部を混合し、２３℃で３０分間攪拌した後、５℃まで冷却した。得られた混合溶液に、式（Ｉ－１－ｆ）で表される化合物３２．４９部を添加し、２３℃で１８時間攪拌した。得られた反応混合物に、ｎ－ヘプタン３００部及び１０％炭酸カリウム水溶液１５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水９０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。回収された有機層に５％シュウ酸水溶液１６０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水９０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮混合物をカラムクロマトグラフィー（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝５／１）により分取することにより、式（Ｉ－１－ｇ）で表される化合物３３．６６部を得た。

式（Ｉ－１－ｇ）で表される化合物５．００部及びメチルイソブチルケトン２０部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、２．５％ｐ－トルエンスルホン酸水溶液１０部を滴下し、２３℃で１８時間攪拌した。得られた反応混合物に、メチルイソブチルケトン３０部及びイオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮混合物をカラムクロマトグラフィー（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝１／１）により分取することにより、式（Ｉ－１－ｈ）で表される化合物１．８４部を得た。

式（Ｉ－１－ｉ）で表される塩５．００部及びアセトニトリル３０部を混合し、その後、４０℃で１時間攪拌した。得られた混合物に、４０℃で、式（Ｉ－１－ｊ）で表される化合物２．４１部を１０分かけて添加し、７０℃に昇温後、７０℃で２時間撹拌することにより、式（Ｉ－１－ｋ）で表される塩を含む溶液を得た。得られた式（Ｉ－１－ｋ）で表される塩を含む溶液を２３℃まで冷却した後、式（Ｉ－１－ｈ）で表される化合物１．５７部を添加し、２３℃で１８時間攪拌した。得られた反応物に、クロロホルム５０部、イオン交換水２０部及び飽和炭酸水素ナトリウム水溶液５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－１）で表される塩４．６８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３６３．０ Example 1: Synthesis of salt represented by formula (I-1)

25 parts of the compound represented by the formula (I-1-a), 4.61 parts of the salt represented by the formula (I-1-c) and 100 parts of chloroform were mixed and stirred at 23° C. for 30 minutes. 19.86 parts of the compound represented by formula (I-1-b) was added to the obtained mixed solution, and the mixture was stirred at 23° C. for 2 hours. 180 parts of chloroform and 155 parts of a 10% aqueous potassium carbonate solution were added to the resulting reaction mixture, and the mixture was stirred at 23° C. for 30 minutes. After adding 60 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated four times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to column chromatography (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=5/1). By fractionating, 38.89 parts of the compound represented by formula (I-1-d) was obtained.

38.86 parts of the compound represented by formula (I-1-d) and 200 parts of acetonitrile were mixed, stirred at 23°C for 30 minutes, and then cooled to 5°C. A mixed solution of 3.53 parts of sodium borohydride and 52.95 parts of ion-exchanged water was added to the obtained mixed solution, and the mixture was stirred at 23° C. for 18 hours. After concentrating the resulting reaction mixture, 230 parts of tert-butyl methyl ether and 90 parts of ion-exchanged water were added to the concentration residue, and the mixture was stirred at 23° C. for 30 minutes. After adding 90 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to column chromatography (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=2/1). By fractionating, 36.93 parts of the compound represented by formula (I-1-e) was obtained.

36.93 parts of the compound represented by the formula (I-1-e), 30.56 parts of pyridine, 8.58 parts of dimethylaminopyridine and 180 parts of methyl isobutyl ketone are mixed and stirred at 23°C for 30 minutes, Cool to 5°C. 32.49 parts of the compound represented by formula (I-1-f) was added to the obtained mixed solution, and the mixture was stirred at 23° C. for 18 hours. 300 parts of n-heptane and 150 parts of a 10% aqueous potassium carbonate solution were added to the resulting reaction mixture, and the mixture was stirred at 23° C. for 30 minutes. After adding 90 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated 5 times. After adding 160 parts of a 5% aqueous oxalic acid solution to the recovered organic layer and stirring at 23° C. for 30 minutes, the organic layer was taken out by liquid separation. After adding 90 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to column chromatography (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=5/1). By fractionating, 33.66 parts of the compound represented by the formula (I-1-g) was obtained.

5.00 parts of the compound represented by formula (I-1-g) and 20 parts of methyl isobutyl ketone were mixed and stirred at 23° C. for 30 minutes. 10 parts of a 2.5% p-toluenesulfonic acid aqueous solution was added dropwise to the resulting mixed solution, and the mixture was stirred at 23° C. for 18 hours. 30 parts of methyl isobutyl ketone and 20 parts of ion-exchanged water were added to the obtained reaction mixture, and the mixture was stirred at 23° C. for 30 minutes. After adding 20 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to column chromatography (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=1/1). By fractionating, 1.84 parts of the compound represented by the formula (I-1-h) was obtained.

5.00 parts of the salt represented by the formula (I-1-i) and 30 parts of acetonitrile were mixed and then stirred at 40° C. for 1 hour. To the resulting mixture, 2.41 parts of the compound represented by the formula (I-1-j) is added at 40°C over 10 minutes, heated to 70°C, and stirred at 70°C for 2 hours. A solution containing a salt represented by the formula (I-1-k) was obtained. After cooling the obtained solution containing the salt represented by the formula (I-1-k) to 23°C, 1.57 parts of the compound represented by the formula (I-1-h) was added, and the temperature was kept at 23°C. and stirred for 18 hours. 50 parts of chloroform, 20 parts of ion-exchanged water and 5 parts of a saturated sodium bicarbonate aqueous solution were added to the resulting reactant, stirred at 23° C. for 30 minutes, allowed to stand, and separated. 20 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes, allowed to stand still, and separated to wash the organic layer with water. This washing operation was repeated twice. The collected organic layer was concentrated, 20 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 4.68 parts of the salt represented by formula (I-1).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 363.0

式（Ｉ－２－ｉ）で表される塩３．４４部及びアセトニトリル３０部を混合し、その後、４０℃で１時間攪拌した。得られた混合物に、４０℃で、式（Ｉ－１－ｊ）で表される化合物１．２１部を１０分かけて添加し、７０℃に昇温後、７０℃で２時間撹拌することにより、式（Ｉ－２－ｋ）で表される塩を含む溶液を得た。得られた式（Ｉ－２－ｋ）で表される塩を含む溶液を２３℃まで冷却した後、式（Ｉ－１－ｈ）で表される化合物０．７９部を添加し、２３℃で１８時間攪拌した。得られた反応物に、クロロホルム５０部、イオン交換水２０部及び飽和炭酸水素ナトリウム水溶液５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－２）で表される塩３．１２部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５７１．２ Example 2: Synthesis of salt represented by formula (I-2)

3.44 parts of the salt represented by the formula (I-2-i) and 30 parts of acetonitrile were mixed and then stirred at 40° C. for 1 hour. To the resulting mixture, 1.21 parts of the compound represented by the formula (I-1-j) is added at 40°C over 10 minutes, heated to 70°C, and stirred at 70°C for 2 hours. A solution containing a salt represented by the formula (I-2-k) was obtained. After cooling the obtained solution containing the salt represented by the formula (I-2-k) to 23°C, 0.79 parts of the compound represented by the formula (I-1-h) was added, and the temperature was kept at 23°C. and stirred for 18 hours. 50 parts of chloroform, 20 parts of ion-exchanged water and 5 parts of a saturated sodium bicarbonate aqueous solution were added to the resulting reactant, stirred at 23° C. for 30 minutes, allowed to stand, and separated. 20 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes, allowed to stand still, and separated to wash the organic layer with water. This washing operation was repeated twice. The collected organic layer was concentrated, 20 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 3.12 parts of the salt represented by the formula (I-2).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 571.2

式（Ｉ－１１－ｉ）で表される塩３．４４部及びアセトニトリル３０部を混合し、その後、４０℃で１時間攪拌した。得られた混合物に、４０℃で、式（Ｉ－１－ｊ）で表される化合物１．２１部を１０分かけて添加し、７０℃に昇温後、７０℃で２時間撹拌することにより、式（Ｉ－１１－ｋ）で表される塩を含む溶液を得た。得られた式（Ｉ－１１－ｋ）で表される塩を含む溶液を２３℃まで冷却した後、式（Ｉ－１－ｈ）で表される化合物０．７９部を添加し、２３℃で１８時間攪拌した。得られた反応物に、クロロホルム５０部、イオン交換水２０部及び飽和炭酸水素ナトリウム水溶液５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－１１）で表される塩２．６８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５７１．２ Example 3: Synthesis of salt represented by formula (I-11)

3.44 parts of the salt represented by the formula (I-11-i) and 30 parts of acetonitrile were mixed and then stirred at 40° C. for 1 hour. To the resulting mixture, 1.21 parts of the compound represented by the formula (I-1-j) is added at 40°C over 10 minutes, heated to 70°C, and stirred at 70°C for 2 hours. A solution containing the salt represented by the formula (I-11-k) was obtained. After cooling the obtained solution containing the salt represented by the formula (I-11-k) to 23°C, 0.79 parts of the compound represented by the formula (I-1-h) was added, and the temperature was kept at 23°C. and stirred for 18 hours. 50 parts of chloroform, 20 parts of ion-exchanged water and 5 parts of a saturated sodium bicarbonate aqueous solution were added to the resulting reactant, stirred at 23° C. for 30 minutes, allowed to stand, and separated. 20 parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23° C. for 30 minutes, allowed to stand still, and separated to wash the organic layer with water. This washing operation was repeated twice. The collected organic layer was concentrated, 20 parts of tert-butyl methyl ether was added to the obtained concentrate, and the mixture was stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 2.68 parts of the salt represented by the formula (I-11).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 571.2

式（Ｉ－２－ｉ）で表される塩３．４４部及びアセトニトリル３０部を混合し、その後、４０℃で１時間攪拌した。得られた混合物に、４０℃で、式（Ｉ－１－ｊ）で表される化合物１．２１部を１０分かけて添加し、７０℃に昇温後、７０℃で２時間撹拌することにより、式（Ｉ－２－ｋ）で表される塩を含む溶液を得た。得られた式（Ｉ－２－ｋ）で表される塩を含む溶液を２３℃まで冷却した後、式（Ｉ－５－ｈ）で表される化合物０．８４部を添加し、２３℃で１８時間攪拌した。得られた反応物に、クロロホルム５０部、イオン交換水２０部及び飽和炭酸水素ナトリウム水溶液５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－５）で表される塩２．６４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５８５．２ Example 4: Synthesis of salt represented by formula (I-5)

3.44 parts of the salt represented by the formula (I-2-i) and 30 parts of acetonitrile were mixed and then stirred at 40° C. for 1 hour. To the resulting mixture, 1.21 parts of the compound represented by the formula (I-1-j) is added at 40°C over 10 minutes, heated to 70°C, and stirred at 70°C for 2 hours. A solution containing a salt represented by the formula (I-2-k) was obtained. After cooling the obtained solution containing the salt represented by the formula (I-2-k) to 23°C, 0.84 parts of the compound represented by the formula (I-5-h) was added, and the temperature was kept at 23°C. and stirred for 18 hours. 50 parts of chloroform, 20 parts of ion-exchanged water and 5 parts of a saturated sodium bicarbonate aqueous solution were added to the resulting reactant, stirred at 23° C. for 30 minutes, allowed to stand, and separated. 20 parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23° C. for 30 minutes, allowed to stand still, and separated to wash the organic layer with water. This washing operation was repeated twice. The collected organic layer was concentrated, 20 parts of tert-butyl methyl ether was added to the obtained concentrate, and the mixture was stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 2.64 parts of the salt represented by the formula (I-5).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 585.2

式（Ｉ－１５－ａ）で表される化合物２０部、式（Ｉ－１－ｃ）で表される塩２．９２部及びクロロホルム１００部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、式（Ｉ－１－ｂ）で表される化合物１２．５７部を添加し、２３℃で２時間攪拌した。得られた反応混合物に、クロロホルム１２０部及び１０％炭酸カリウム水溶液１００部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水６０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を４回繰り返した。得られた有機層を濃縮し、濃縮混合物をカラムクロマトグラフィー（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝５／１）により分取することにより、式（Ｉ－１５－ｄ）で表される化合物２３．５６部を得た。

式（Ｉ－１５－ｄ）で表される化合物２０部及びアセトニトリル１００部を混合し、２３℃で３０分間攪拌した後、５℃まで冷却した。得られた混合溶液に、水素化ホウ素ナトリウム１．５５部及びイオン交換水２３．２２部の混合溶液を添加し、２３℃で１８時間攪拌した。得られた反応混合物を濃縮した後、濃縮残に、ｔｅｒｔ－ブチルメチルエーテル１００部及びイオン交換水４０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水４０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮混合物をカラムクロマトグラフィー（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝２／１）により分取することにより、式（Ｉ－１５－ｅ）で表される化合物１４．１２部を得た。

式（Ｉ－１５－ｅ）で表される化合物１４部、ピリジン０．８９部、ジメチルアミノピリジン２．７８部及びメチルイソブチルケトン６０部を混合し、２３℃で３０分間攪拌した後、５℃まで冷却した。得られた混合溶液に、式（Ｉ－１－ｆ）で表される化合物１０．５１部を添加し、２３℃で１８時間攪拌した。得られた反応混合物に、ｎ－ヘプタン１００部及び１０％炭酸カリウム水溶液５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水３０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。回収された有機層に５％シュウ酸水溶液６０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水３０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮混合物をカラムクロマトグラフィー（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝５／１）により分取することにより、式（Ｉ－１５－ｇ）で表される化合物１０．１２部を得た。

式（Ｉ－１５－ｇ）で表される化合物５部及びメチルイソブチルケトン２０部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、２．５％ｐ－トルエンスルホン酸水溶液１０部を滴下し、２３℃で１８時間攪拌した。得られた反応混合物に、メチルイソブチルケトン３０部及びイオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層にイオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮混合物をカラムクロマトグラフィー（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝１／１）により分取することにより、式（Ｉ－１５－ｈ）で表される化合物１．７７部を得た。

式（Ｉ－１－ｉ）で表される塩５．００部及びアセトニトリル３０部を混合し、その後、４０℃で１時間攪拌した。得られた混合物に、４０℃で、式（Ｉ－１－ｊ）で表される化合物２．４１部を１０分かけて添加し、７０℃に昇温後、７０℃で２時間撹拌することにより、式（Ｉ－１－ｋ）で表される塩を含む溶液を得た。得られた式（Ｉ－１－ｋ）で表される塩を含む溶液を２３℃まで冷却した後、式（Ｉ－１５－ｈ）で表される化合物１．８４部を添加し、２３℃で１８時間攪拌した。得られた反応物に、クロロホルム５０部、イオン交換水２０部及び飽和炭酸水素ナトリウム水溶液５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－１５）で表される塩４．４９部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ３９９．０ Example 5: Synthesis of salt represented by formula (I-15)

20 parts of the compound represented by the formula (I-15-a), 2.92 parts of the salt represented by the formula (I-1-c) and 100 parts of chloroform were mixed and stirred at 23° C. for 30 minutes. 12.57 parts of the compound represented by formula (I-1-b) was added to the obtained mixed solution, and the mixture was stirred at 23° C. for 2 hours. 120 parts of chloroform and 100 parts of a 10% aqueous potassium carbonate solution were added to the resulting reaction mixture, and the mixture was stirred at 23° C. for 30 minutes. After adding 60 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated four times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to column chromatography (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=5/1). By fractionating, 23.56 parts of the compound represented by the formula (I-15-d) was obtained.

20 parts of the compound represented by the formula (I-15-d) and 100 parts of acetonitrile were mixed, stirred at 23°C for 30 minutes, and then cooled to 5°C. A mixed solution of 1.55 parts of sodium borohydride and 23.22 parts of ion-exchanged water was added to the obtained mixed solution, and the mixture was stirred at 23° C. for 18 hours. After concentrating the resulting reaction mixture, 100 parts of tert-butyl methyl ether and 40 parts of ion-exchanged water were added to the concentration residue, and the mixture was stirred at 23° C. for 30 minutes. After adding 40 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to column chromatography (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=2/1). By fractionating, 14.12 parts of the compound represented by the formula (I-15-e) was obtained.

14 parts of the compound represented by the formula (I-15-e), 0.89 parts of pyridine, 2.78 parts of dimethylaminopyridine and 60 parts of methyl isobutyl ketone were mixed, stirred at 23°C for 30 minutes, and then stirred at 5°C. cooled to 10.51 parts of the compound represented by the formula (I-1-f) was added to the obtained mixed solution, and the mixture was stirred at 23° C. for 18 hours. 100 parts of n-heptane and 50 parts of a 10% aqueous potassium carbonate solution were added to the resulting reaction mixture, and the mixture was stirred at 23° C. for 30 minutes. After adding 30 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated 5 times. After adding 60 parts of a 5% aqueous oxalic acid solution to the collected organic layer and stirring at 23° C. for 30 minutes, the organic layer was taken out by liquid separation. After adding 30 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to column chromatography (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=5/1). By fractionating, 10.12 parts of the compound represented by the formula (I-15-g) was obtained.

Five parts of the compound represented by formula (I-15-g) and 20 parts of methyl isobutyl ketone were mixed and stirred at 23° C. for 30 minutes. 10 parts of a 2.5% p-toluenesulfonic acid aqueous solution was added dropwise to the resulting mixed solution, and the mixture was stirred at 23° C. for 18 hours. 30 parts of methyl isobutyl ketone and 20 parts of ion-exchanged water were added to the obtained reaction mixture, and the mixture was stirred at 23° C. for 30 minutes. After adding 20 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the liquid was separated and the organic layer was taken out. This washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was subjected to column chromatography (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate=1/1). By fractionating, 1.77 parts of the compound represented by the formula (I-15-h) was obtained.

5.00 parts of the salt represented by the formula (I-1-i) and 30 parts of acetonitrile were mixed and then stirred at 40° C. for 1 hour. To the resulting mixture, 2.41 parts of the compound represented by the formula (I-1-j) is added at 40°C over 10 minutes, heated to 70°C, and stirred at 70°C for 2 hours. A solution containing a salt represented by the formula (I-1-k) was obtained. After cooling the obtained solution containing the salt represented by the formula (I-1-k) to 23°C, 1.84 parts of the compound represented by the formula (I-15-h) was added, and the temperature was kept at 23°C. and stirred for 18 hours. 50 parts of chloroform, 20 parts of ion-exchanged water and 5 parts of a saturated sodium bicarbonate aqueous solution were added to the resulting reactant, stirred at 23° C. for 30 minutes, allowed to stand, and separated. 20 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes, allowed to stand still, and separated to wash the organic layer with water. This washing operation was repeated twice. The collected organic layer was concentrated, 20 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 4.49 parts of the salt represented by the formula (I-15).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 399.0

式（Ｉ－２－ｉ）で表される塩３．４４部及びアセトニトリル３０部を混合し、その後、４０℃で１時間攪拌した。得られた混合物に、４０℃で、式（Ｉ－１－ｊ）で表される化合物１．２１部を１０分かけて添加し、７０℃に昇温後、７０℃で２時間撹拌することにより、式（Ｉ－２－ｋ）で表される塩を含む溶液を得た。得られた式（Ｉ－２－ｋ）で表される塩を含む溶液を２３℃まで冷却した後、式（Ｉ－１５－ｈ）で表される化合物０．９３部を添加し、２３℃で１８時間攪拌した。得られた反応物に、クロロホルム５０部、イオン交換水２０部及び飽和炭酸水素ナトリウム水溶液５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水２０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を２回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－１６）で表される塩２．９９部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ６０７．１ Example 6: Synthesis of salt represented by formula (I-16)

3.44 parts of the salt represented by the formula (I-2-i) and 30 parts of acetonitrile were mixed and then stirred at 40° C. for 1 hour. To the resulting mixture, 1.21 parts of the compound represented by the formula (I-1-j) is added at 40°C over 10 minutes, heated to 70°C, and stirred at 70°C for 2 hours. A solution containing a salt represented by the formula (I-2-k) was obtained. After cooling the obtained solution containing the salt represented by the formula (I-2-k) to 23°C, 0.93 parts of the compound represented by the formula (I-15-h) was added, and the temperature was kept at 23°C. and stirred for 18 hours. 50 parts of chloroform, 20 parts of ion-exchanged water and 5 parts of a saturated sodium bicarbonate aqueous solution were added to the resulting reactant, stirred at 23° C. for 30 minutes, allowed to stand, and separated. 20 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23° C. for 30 minutes, allowed to stand still, and separated to wash the organic layer with water. This washing operation was repeated twice. The collected organic layer was concentrated, 20 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 2.99 parts of the salt represented by the formula (I-16).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 607.1

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

Example 7 [Synthesis of Resin A1-1]
As monomers, monomer (ax-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (I-1) are used, and the molar ratio [monomer (ax-1): monomer ( a1-1-3):monomer (a1-2-6):monomer (I-1)] are mixed in a ratio of 35:24:38:3, and all the monomers are added to this monomer mixture. 1.5 times the mass of methyl isobutyl ketone was mixed with respect to the total mass of . To the resulting mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and the mixture was heated at 83°C for about 5 hours to polymerize. did Thereafter, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A1-1 (copolymer) having a weight average molecular weight of about 5.2×10 ³ . obtained with a yield of 70%. This resin A1-1 has the following structural units.

Example 8 [Synthesis of Resin A1-2]
As monomers, monomer (ax-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (I-2) are used, and the molar ratio [monomer (ax-1): monomer ( a1-1-3):monomer (a1-2-6):monomer (I-2)] are mixed in a ratio of 35:24:38:3, and all the monomers are added to this monomer mixture. 1.5 times the mass of methyl isobutyl ketone was mixed with respect to the total mass of . To the resulting mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and the mixture was heated at 83° C. for about 5 hours to polymerize. did Thereafter, a 25% aqueous tetramethylammonium hydroxide solution was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A1-2 (copolymer) having a weight average molecular weight of about 5.5×10 ³ . A yield of 75% was obtained. This resin A1-2 has the following structural units.

Example 9 [Synthesis of Resin A1-3]
As monomers, monomer (ax-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (I-11) are used, and the molar ratio [monomer (ax-1): monomer ( a1-1-3):monomer (a1-2-6):monomer (I-11)] are mixed in a ratio of 35:24:38:3, and all the monomers are added to this monomer mixture. 1.5 times the total mass of methyl isobutyl ketone was mixed. To the resulting mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and the mixture was heated at 83°C for about 5 hours to polymerize. did Thereafter, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A1-3 (copolymer) having a weight average molecular weight of about 5.4×10 ³ . A yield of 71% was obtained. This resin A1-3 has the following structural units.

Example 10 [Synthesis of Resin A1-4]
As monomers, monomer (ax-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (I-5) are used, and the molar ratio [monomer (ax-1): monomer ( a1-1-3):monomer (a1-2-6):monomer (I-5)] are mixed in a ratio of 35:24:38:3, and all the monomers are added to this monomer mixture. 1.5 times the total mass of methyl isobutyl ketone was mixed. To the resulting mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and the mixture was heated at 83°C for about 5 hours to polymerize. did Thereafter, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A1-4 (copolymer) having a weight average molecular weight of about 5.1×10 ³ . obtained at a rate of 60%. This resin A1-4 has the following structural units.

Example 11 [Synthesis of Resin A1-5]
As monomers, monomer (ax-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (I-15) are used, and the molar ratio [monomer (ax-1): monomer ( a1-1-3):monomer (a1-2-6):monomer (I-15)] are mixed in a ratio of 35:24:38:3, and all the monomers are added to this monomer mixture. 1.5 times the total mass of methyl isobutyl ketone was mixed. To the resulting mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and the mixture was heated at 83°C for about 5 hours to polymerize. did Thereafter, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A1-5 (copolymer) having a weight average molecular weight of about 5.7×10 ³ . A yield of 65% was obtained. This resin A1-5 has the following structural units.

Example 12 [Synthesis of Resin A1-6]
As monomers, monomer (ax-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (I-16) are used, and the molar ratio [monomer (ax-1): monomer ( a1-1-3):monomer (a1-2-6):monomer (I-16)] are mixed in a ratio of 35:24:38:3, and all the monomers are added to this monomer mixture. 1.5 times the total mass 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 83° C. for about 5 hours to carry out polymerization. rice field. Thereafter, a 25% aqueous tetramethylammonium hydroxide solution was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin A1-6 (copolymer) having a weight average molecular weight of about 5.9×10 ³ . A yield of 68% was obtained. This resin A1-6 has the following structural units.

Synthesis Example 1 [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 so that the ratio is 38:24:38, and further, 1.5 times the mass of the total mass of all the 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. rice field. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and 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 4.6×10 ³ . A yield of 74% was obtained. This resin A2-1 has the following structural units.

Synthesis Example 2 [Synthesis of Resin AX1-1]
As monomers, monomer (ax-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (IX-1) are used, and the molar ratio [monomer (ax-1): monomer ( a1-1-3):monomer (a1-2-6):monomer (IX-1)] are mixed in a ratio of 35:24:38:3, and all the monomers are added to this monomer mixture. 1.5 times the total mass 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 83° C. for about 5 hours to carry out polymerization. rice field. Thereafter, a 25% aqueous tetramethylammonium hydroxide solution was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin AX1-1 (copolymer) having a weight average molecular weight of about 5.2×10 ³ . A yield of 68% was obtained. This resin AX1-1 has the following structural units.

Synthesis Example 3 [Synthesis of resin AX1-2]
As monomers, monomer (ax-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (IX-2) are used, and the molar ratio [monomer (ax-1): monomer ( a1-1-3):monomer (a1-2-6):monomer (IX-2)] are mixed in a ratio of 35:24:38:3, and all the monomers are added to this monomer mixture. 1.5 times the mass of methyl isobutyl ketone was mixed with respect to the total mass of . To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol % with respect to the total number of moles of all monomers, and the mixture was heated at 83° C. for about 5 hours to carry out polymerization. rice field. Thereafter, a 25% aqueous tetramethylammonium hydroxide solution was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin AX1-2 (copolymer) having a weight average molecular weight of about 5.5×10 ³ . A yield of 75% was obtained. This resin AX1-2 has the following structural units.

Synthesis Example 4 [Synthesis of Resin AX1-3]
As monomers, monomer (ax-1), monomer (a1-1-3), monomer (a1-2-6) and monomer (IX-3) are used, and the molar ratio [monomer (ax-1): monomer ( a1-1-3):monomer (a1-2-6):monomer (IX-3)] are mixed in a ratio of 35:24:38:3, and all the monomers are added to this monomer mixture. 1.5 times the total mass 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 83° C. for about 5 hours to carry out polymerization. rice field. Thereafter, a 25% tetramethylammonium hydroxide aqueous solution was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The collected organic layer is poured into a large amount of n-heptane to precipitate the resin, filtered and collected to obtain resin AX1-3 (copolymer) having a weight average molecular weight of about 5.4×10 ³ . A yield of 64% was obtained. This resin AX1-3 has the following structural units.

<Preparation of resist composition>
A resist composition was prepared by mixing each component shown in Table 2 and the following solvent, and filtering the resulting mixture through a fluororesin filter having a pore size of 0.2 μm.

ＩＸ－１：式（ＩＸ－１）で表される塩；特開２０１１－１９０２４６号公報記載の方法で合成

ＩＸ－２：式（ＩＸ－２）で表される塩；特開２０１４－１９７１６８号公報記載の方法を参考にして合成

ＩＸ－３：式（ＩＸ－３）で表される塩；特開２０１１－１９０２４６号公報記載の方法を参考にして合成

＜クエンチャー（Ｃ）＞
Ｃ１－１：特開２０１１－３９５０２号公報記載の方法で合成

＜溶剤（Ｅ）＞
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 １００部
γ－ブチロラクトン ５部 <Resin (A)>
A1-1 to A1-6, A2-1, AX1-1 to AX1-3: Resin A1-1 to Resin A1-6, Resin A2-1, Resin AX1-1 to Resin AX1-3
<Salt (I)>
I-2: Salt Represented by Formula (I-2) <Acid Generator (B)>
B1-43: a salt represented by the formula (B1-43) (synthesized according to the examples of JP-A-2016-47815)

IX-1: a salt represented by the formula (IX-1); synthesized by the method described in JP-A-2011-190246

IX-2: a salt represented by the formula (IX-2); synthesized with reference to the method described in JP-A-2014-197168

IX-3: a salt represented by the formula (IX-3); synthesized with reference to the method described in JP-A-2011-190246

<Quencher (C)>
C1-1: synthesized by the method described in JP-A-2011-39502

<Solvent (E)>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 100 parts γ-butyrolactone 5 parts

(Evaluation of resist composition by electron beam exposure)
A 6-inch silicon wafer was treated with hexamethyldisilazane at 90° C. for 60 seconds on a direct hotplate. This silicon wafer was spin-coated with the resist composition so that the film thickness of the composition layer was 0.04 μm. After that, it was pre-baked for 60 seconds on a direct hot plate at the temperature shown in the "PB" column of Table 2 to form a composition layer. A line-and-space pattern was directly drawn on the composition layer formed on the wafer using an electron beam lithography machine ["HL-800D 50 keV" manufactured by Hitachi, Ltd.] while changing the exposure dose stepwise. .
After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 2 for 60 seconds, and puddle development was performed for 60 seconds with a 2.38% by mass tetramethylammonium hydroxide aqueous solution. , a resist pattern was obtained.
The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the effective sensitivity was defined as the exposure dose at which the line width and space width of the 60 nm line and space pattern were 1:1.

Line Edge Roughness Evaluation (LER): Line edge roughness was obtained by measuring the unevenness amplitude of the side wall surface of the resist pattern manufactured at effective sensitivity with a scanning electron microscope. Table 3 shows the results.

From the above results, according to the salt of the present invention, the resin containing a structural unit derived from the salt, the resist composition containing the salt, and the resist composition containing the resin, the resist pattern obtained using the salt It can be seen that the line edge roughness (LER) is good.

The salt of the present invention, the resin containing a structural unit derived from the salt, the resist composition containing the salt, and the resist composition containing the resin exhibit good line edge roughness of resist patterns obtained using the same. , is useful for microfabrication of semiconductors.

Claims (12)

A salt of the formula (I).

[in the formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom or a C 1-6 perfluoroalkyl group.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² may be the same or different.
X ¹ is *-CO-O-, *-O-CO- or *-O-CO-O- ( where * is C(R ¹ )(R ² ) or C(Q ¹ )(Q ² ) represents the bonding position with ).
L ¹ represents a single bond or a divalent hydrocarbon group having 1 to 36 carbon atoms , and the hydrocarbon group is an alkanediyl group having 1 to 6 carbon atoms or an alkanediyl group having 1 to 6 carbon atoms and carbon A group in combination with an alicyclic hydrocarbon group of numbers 3 to 18 (with the proviso that —CH ₂ — contained in the alkanediyl group and the alicyclic hydrocarbon group is —O—, —S—, —CO - or -SO ₂ - may be substituted. ),
Ar represents a phenylene group optionally having a substituent.
R ³ represents an alkyl group having 1 to 6 carbon atoms.
R ⁴ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
^R5 represents a hydrogen atom or a methyl group.
ZI ⁺ represents an organic cation. ] The salt according to claim 1 , wherein L ¹ is a single bond or an alkanediyl group having 1 to 6 carbon atoms. L. ¹ is a divalent hydrocarbon group having 1 to 36 carbon atoms,
The hydrocarbon group is a group in which an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are combined (provided that the alkanediyl group and the alicyclic hydrocarbon group include -CH ₂ - is -O-, -S-, -CO- or -SO ₂ - may be replaced. ) and
The alicyclic hydrocarbon group having 3 to 18 carbon atoms is a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, and a cyclohexene-3,6-diyl group. group, cyclooctane-1,5-diyl group, norbornane-1,4-diyl group, norbornane-2,5-diyl group, 5-norbornene-2,3-diyl group, adamantane-1,5-diyl group or The salt according to claim 1, which is an adamantane-2,6-diyl group. 3. The salt according to claim 1 or 2, wherein the anion of the salt represented by formula (I) is an anion represented by any one of formulas (Ia-1) to (Ia-24).

An acid generator containing the salt according to any one of claims 1 to 4. A resin having structural units derived from the salt according to any one of claims 1 to 4. 7. The resin of claim 6, further comprising structural units having acid labile groups. A resist composition comprising the resin according to claim 6 or 7 and an acid generator. 9. The resist composition according to claim 8, wherein the acid generator contains a salt represented by formula (B1).

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a 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—; A hydrogen atom contained in may be substituted with a fluorine atom or a hydroxy group.
Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and included in the alicyclic hydrocarbon group- CH ₂ - may be replaced by -O-, -S(O) ₂ - or -CO-.
Z ⁺ represents an organic cation. ] A resist composition comprising the acid generator according to claim 5 and a resin having an acid-labile group. 11. The resist composition according to any one of claims 8 to 10, which contains 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 8 to 11 onto a substrate;
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer;
(4) A process of heating the composition layer after exposure, and (5) a process of developing the composition layer after heating.