JP2019006761A - Salt, acid generator, resist composition, and method for producing resist pattern - Google Patents

Abstract

To provide a salt capable of producing a resist pattern with good line edge roughness (LER), a resist composition containing the same, and a method for producing a resist pattern.SOLUTION: The salt is represented by formula (I) [where Qand Qeach independently represent a fluorine atom or a C1-6 perfluoroalkyl group; Rand Reach independently represent H, a fluorine atom, or a C1-6 perfluoroalkyl group; z represents an integer of 0-6; when z is 2 or more, a plurality of R's and R's may be the same as or different from each other; Xrepresents *-CO-O- (* represents a bond with C(R)(R) or C(Q)(Q)) or the like; Lrepresents a C1-36 divalent hydrocarbon group or the like; Rrepresents H or a C1-6 alkyl group; and Zrepresents an organic cation].SELECTED DRAWING: None

Description

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

Patent Document 1 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator.

Patent Document 2 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator.

JP2012-224615A JP 2013-54344 A

  This invention makes it a subject to provide the salt which can obtain the resist pattern whose line edge roughness (LER) is favorable rather than the resist composition containing said 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。
Ｘ^１は、＊−ＣＯ−Ｏ−、＊−Ｏ−ＣＯ−、＊−Ｏ−ＣＯ−Ｏ−又は−Ｏ−（但し、＊は、Ｃ（Ｒ^１）（Ｒ^２）又はＣ（Ｑ^１）（Ｑ^２）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−Ｓ（Ｏ）_２−に置き換わっていてもよい。
Ｒ^３は、水素原子又は炭素数１〜６のアルキル基を表す。
Ｚ^＋は有機カチオンを表す。］
［２］ Ｘ^１が、＊−ＣＯ−Ｏ−（但し、＊は、Ｃ（Ｒ^１）（Ｒ^２）又はＣ（Ｑ^１）（Ｑ^２）との結合位を表す。）である［１］に記載の塩。
［３］ Ｌ^１が、炭素数１〜６のアルカンジイル基又は
炭素数３〜１８の脂環式炭化水素基と炭素数１〜６のアルカンジイル基とから形成される２価の炭化水素基（該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。）である［１］又は［２］記載の塩。
［４］ ［１］〜［３］のいずれかに記載の塩を含有する酸発生剤。
［５］ ［４］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。
［６］ さらに、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［５］記載のレジスト組成物。
［７］ （１）［５］又は［６］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 the formula (I).

[In the formula (I),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represents 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, the plurality of R ¹ and R ² may be the same as or different from each other.
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 C1-C36 divalent hydrocarbon group which may have a single bond or a substituent, and —CH ₂ — contained in the hydrocarbon group is —O—, —S. -, -CO- or -S (O) _2- may be substituted.
R ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Z ⁺ represents an organic cation. ]
[2] X ¹ is * —CO—O— (where * represents a bonding position with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² )). ] The salt of description.
[3] L ¹ is a divalent hydrocarbon group formed from an alkanediyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms and an alkanediyl group having 1 to 6 carbon atoms. The salt according to [1] or [2], wherein —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—.
[4] An acid generator containing the salt according to any one of [1] to [3].
[5] A resist composition comprising the acid generator according to [4] and a resin having an acid labile group.
[6] The resist composition according to [5], further comprising a salt that generates an acid having a lower acidity than an acid generated from the acid generator.
[7] (1) A step of applying the resist composition according to [5] or [6] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.

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

In this specification, 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 acrylate and methacrylate” and “at least one selected from the group consisting of acrylic acid and methacrylic acid”. "Means. When structural units having “CH ₂ ═C (CH ₃ ) —CO—” or “CH ₂ ═CH—CO—” are exemplified, the structural units having both groups are also exemplified. Shall. Moreover, in the group described in the present specification, any group that can take both a linear structure and a branched structure may be used. When stereoisomers exist, all stereoisomers are included.
In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described later from the total amount of the resist composition.

<Salt represented by formula (I)>
The present invention relates to a salt represented by the formula (I) (hereinafter sometimes referred to as “salt (I)”).

  Of the salt (I), the negatively charged side may be referred to as “anion (I)” and the positively charged side may be referred to as “cation (I)”.

As the perfluoroalkyl group for Q ¹ , Q ² , R ¹ and R ² , a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a 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 0.

X ¹ is preferably * —CO—O— (* represents a bond with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² )).

Examples of the divalent hydrocarbon group having 1 to 36 carbon atoms of L ¹ include an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a divalent aromatic hydrocarbon group. The divalent hydrocarbon group which combined 2 or more types among these groups may be sufficient.

Examples of the alkanediyl group include 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 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- Examples thereof include 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.
Examples of the monocyclic divalent alicyclic saturated hydrocarbon group include cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1, And cycloalkanediyl groups such as a 5-diyl group.
Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6- A diyl group etc. are mentioned.
Examples of the divalent aromatic hydrocarbon group include phenylene group, naphthylene group, anthrylene group, p-methylphenylene group, p-tert-butylphenylene group, p-adamantylphenylene group, tolyl group, xylylene group, cumenylene group, mesitylene group. Group, biphenylene group, phenanthrylene group, 2,6-diethylphenylene group, aryl group such as 2-methyl-6-ethylphenylene group, and the like.

As the substituent that the hydrocarbon group of L ¹ has, 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 Among these groups, a group in which two or more kinds are combined is exemplified.
Examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group.
Examples of the acyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group having 2 to 13 carbon atoms include acetyloxy group, propionyloxy group, and butyryloxy group.
The divalent hydrocarbon group having 2 to 36 carbon atoms represented by L ¹ may have one substituent or a plurality of substituents.

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

The divalent hydrocarbon group having 1 to 36 carbon atoms represented by L ¹ is an alkanediyl group having 1 to 6 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 3 to 3 carbon atoms. A divalent hydrocarbon group formed from an 18 divalent alicyclic hydrocarbon group and an alkanediyl group having 1 to 6 carbon atoms (—CH ₂ — contained in the hydrocarbon group is —O— or preferably -CO- to a substituted or may be), a methylene group, an ethylene group, a cyclohexane diyl group, adamantane-diyl ^{group, * 1A 11 -X 1A -A 12} -. , a group represented by * 1A ¹³ -X ^1A - group represented ^{by, * 1-X 1A -A 14} - is more preferably a group represented by a methylene ^{group, * 1A 11 -X 1A -A 12} - And a group represented by * 1-X ^1A -A ^14- is more preferable. Good.
X ^1A represents a C 3-18 divalent alicyclic hydrocarbon group, and is preferably a cyclohexanediyl group or an adamantanediyl group.
A ¹¹ , A ¹² , A ¹³ and A ¹⁴ are each independently an alkanediyl group having 1 to 6 carbon atoms (—CH ₂ — contained in the alkanediyl group is replaced by —O— or —CO—). May be present). A ¹¹ and A ¹³ are preferably methylene groups. A ¹² and A ¹⁴ are preferably —CO—O—CH ₂ — or —O—CO—O—CH ₂ —.
* 1 represents a bond to ^{X 1.}

Examples of the alkyl group for R ³ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group.
R ³ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and further preferably a methyl group.

Examples of the anion (I) include the following anions. Especially, the anion represented by Formula (Ia-1)-Formula (Ia-14) is preferable, and the anion represented by Formula (Ia-1)-Formula (Ia-4), Formula (Ia-7) is preferable. More preferred.

Examples of the organic cation of Z ⁺ include an organic onium cation, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an arylsulfonium cation is more preferable. Specifically, a cation represented by any one of formulas (b2-1) to (b2-4) (hereinafter may be referred to as “cation (b2-1)” or the like depending on the formula number). Can be 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 formula (b2-1) to formula (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. The hydrogen atom contained in the alicyclic hydrocarbon group which may be substituted 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. The 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 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 is —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 represents an integer of 0 to 5.
When m2 is 2 or more, the plurality of R ^b7 may be the same or different, and when n2 is 2 or more, the plurality of 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 together to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring is —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 is included in the chain hydrocarbon. The hydrogen atom may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group is an alkoxy group 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 is —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 represents an integer of 0 to 5.
q2 and r2 each independently represents 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, a plurality of R ^b16 are the same or different, when s2 is 2 or more, a plurality of R ^b17 are the same or different, and when t2 is 2 or more, a 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.
Examples of chain hydrocarbon groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl and 2-ethylhexyl alkyl groups. Can be mentioned.
In particular, the chain hydrocarbon group of R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclo group. Examples thereof include cycloalkyl groups such as heptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.

In particular, the alicyclic hydrocarbon group of R ^{b9 to} R ^b12 preferably has 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.

  Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, and a 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 number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

As aromatic hydrocarbon group, phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group, p-adamantylphenyl group , Aryl groups such as a biphenylyl group, a naphthyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.
In addition, when the aromatic hydrocarbon group includes a chain hydrocarbon group or an alicyclic hydrocarbon group, the chain hydrocarbon group having 1 to 18 carbon atoms and the alicyclic hydrocarbon having 3 to 18 carbon atoms. Groups are preferred.
Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group.
Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.

Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkylcarbonyloxy group, methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, pentylcarbonyloxy group Hexylcarbonyloxy group, octylcarbonyloxy group, 2-ethylhexylcarbonyloxy group and the like.

The ring formed by combining R ^b4 and R ^b5 together with the sulfur atom to which they are bonded is monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. The ring may be Examples of the ring include a ring having 3 to 18 carbon atoms, and a ring having 4 to 18 carbon atoms is preferable. Moreover, the ring containing a sulfur atom includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and examples thereof include the following rings.

The ring formed by combining R ^b9 and R ^b10 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
The ring formed by ^combining R ^b11 and R ^b12 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the cation (b2-1) ~ cation (b2-4), cationic (b2-1) is preferably a cation (b2-1), and R ^b4 to R ^b6 are each independently, a carbon number 6 to 36 It is more preferable that the aromatic hydrocarbon group (the 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). It is.

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.

As salt (I), the salt of Table 1-Table 4 is mentioned. For example, in Table 1, salt (I-1) is a salt shown below.

  Especially, salt (I) is salt (I-1)-salt (I-4), salt (I-7), salt (I-15)-salt (I-18), salt (I-21). , Salt (I-29) to salt (I-32), salt (I-35), salt (I-43) to salt (I-46), salt (I-49), salt (I-57) to Salt (I-60), Salt (I-63), Salt (I-71) to Salt (I-74), Salt (I-77), Salt (I-85) to Salt (I-88), Salt (I-91), salt (I-99) to salt (I-102), salt (I-105), salt (I-113) to salt (I-116), and salt (I-119) are preferred.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。Ｒ^５ｘは酸不安定基を表す。）
この反応における酸触媒としては、トリフルオロ酢酸等が挙げられる。
この反応における溶媒としては、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。 <Method for producing salt (I)>
In the salt (I), a salt in which X ¹ is * —CO—O— (a salt represented by the formula (I1)) is, for example, a salt represented by the formula (I1-a) in the presence of an acid catalyst. Then, it can be produced by hydrolysis in a solvent.

(In the formula, all symbols have the same meanings as described above. R ^5x represents an acid labile group.)
Examples of the acid catalyst in this reaction include trifluoroacetic acid.
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

Examples of the salt represented by the formula (I1-a) include salts represented by the following, and can be produced by the method described in JP2013-54344A.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における酸触媒としては、トリフルオロ酢酸等が挙げられる。
この反応における溶媒としては、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。 In the salt (I), a salt (formula (I2) wherein X ¹ is * —CO—O—, L ¹ is * 1-X ^1A —A ¹⁴ —, and A ¹⁴ is —CO—O—CH ₂ —. ) Can be produced, for example, by hydrolyzing the salt represented by the formula (I2-a) in a solvent in the presence of an acid catalyst.

(In the formula, all symbols have the same meaning as described above.)
Examples of the acid catalyst in this reaction include trifluoroacetic acid.
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours 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。）
この反応における溶媒としては、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。 The salt represented by the formula (I2-a) is produced, for example, by reacting the salt represented by the formula (I2-b) with the compound represented by the formula (I2-c) in a solvent. can do.

(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours 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。）
この反応における溶媒としては、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。
式（Ｉ２−ｄ）で表される塩は、例えば、以下で表される塩などが挙げられ、特開２００８−１２７３６７号公報に記載された方法で製造することができる。

The salt represented by the formula (I2-b) can be obtained by reacting the salt represented by the formula (I2-d) with the compound represented by the formula (I2-e) in a solvent. it can.

(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the salt represented by the formula (I2-d) include salts represented by the following, and can be produced by the method described in JP-A-2008-127367.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における還元剤としては、水素化ホウ素ナトリウム等が挙げられる。
この反応における溶媒としては、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℃〜４０℃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 (I2-c) can be produced, for example, by reacting the compound represented by the formula (I2-f) with a reducing agent in a solvent.

(In the formula, all symbols have the same meaning as described above.)
Examples of the reducing agent in this reaction include sodium borohydride.
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually −5 ° C. to 40 ° C., and the reaction time is usually 0.5 hours 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。）
この反応における溶媒としては、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。
式（Ｉ２−ｇ）で表される化合物としては、下記式で表される化合物等が挙げられ、市場より容易に入手できる。

In the compound represented by the formula (I2-f), for example, the compound represented by the formula (I2-g) is mixed with carbonyldiimidazole, and then mixed with the compound represented by the formula (I2-h) in a solvent. It can be produced by reacting.

(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the compound represented by the formula (I2-g) include compounds represented by the following formula, and are easily available 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。）
この反応における溶媒としては、クロロホルム、アセトニトリル、イオン交換水等が挙げられる。
この反応における触媒としては、過酸化水素／蟻酸混合剤、四酸化オスミウム／４−メチルモルホリンＮ−オキシド混合剤等が挙げられる。
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（Ｉ２−ｉ）で表される化合物としては、下記式で表される化合物等が挙げられ、市場より容易に入手できる。

The compound represented by the formula (I2-h) can be produced, for example, by reacting the compound represented by the formula (I2-i) in a solvent in the presence of a catalyst.

(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform, acetonitrile, ion-exchanged water and the like.
Examples of the catalyst in this reaction include a hydrogen peroxide / formic acid mixture, an osmium tetroxide / 4-methylmorpholine N-oxide mixture, and the like.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the compound represented by the formula (I2-i) include compounds represented by the following formula, and are easily available 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。）
この反応における酸触媒としては、トリフルオロ酢酸等が挙げられる。
この反応における溶媒としては、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。 In the salt (I), a salt in which X ¹ is * —O—CO—O— (a salt represented by the formula (I3)) is, for example, a salt represented by the formula (I3-a) It can be produced by hydrolysis in a solvent in the presence of a catalyst.

(In the formula, all symbols have the same meaning as described above.)
Examples of the acid catalyst in this reaction include trifluoroacetic acid.
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours 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。）
この反応における溶媒としては、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。 The salt represented by the formula (I3-a) is produced, for example, by reacting the salt represented by the formula (I3-b) with the compound represented by the formula (I3-c) in a solvent. Can do.

(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

Examples of the compound represented by the formula (I3-c) include compounds represented by the following, and can be produced by the method described in JP2013-54344A.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における溶媒としては、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。
式（Ｉ３−ｄ）で表される塩は、例えば、以下で表される塩などが挙げられ、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。

The salt represented by the formula (I3-b) can be obtained by reacting the salt represented by the formula (I3-d) with the compound represented by the formula (I2-e) in a solvent. it can.

(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the salt represented by the formula (I3-d) include salts represented by the following, and can be produced by the method described in JP2012-193170A.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における酸触媒としては、トリフルオロ酢酸等が挙げられる。
この反応における溶媒としては、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。 In the salt (I), a salt in which X ¹ is * —O—CO— (a salt represented by the formula (I4)) is, for example, a salt represented by the formula (I4-a) in the presence of an acid catalyst. Then, it can be produced by hydrolysis in a solvent.

(In the formula, all symbols have the same meaning as described above.)
Examples of the acid catalyst in this reaction include trifluoroacetic acid.
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours 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。）
この反応における溶媒としては、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。 The salt represented by the formula (I4-a) is obtained by, for example, reacting a compound represented by the formula (I4-c) with carbonyldiimidazole in a solvent, and further represented by the formula (I3-d). Can be produced by reacting with a salt to be produced.

(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

Examples of the compound represented by the formula (I4-c) include compounds represented by the following, 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。）
この反応における酸触媒としては、トリフルオロ酢酸等が挙げられる。
この反応における溶媒としては、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。 In the salt (I), a salt in which X ¹ is * —O—CO—, L ¹ is * 1-X ^1A —A ¹⁴ —, and A ¹⁴ is —CO—O—CH ₂ — (formula (Salt represented by (I4A)) can be produced, for example, by hydrolyzing a salt represented by the formula (I4A-a) in a solvent in the presence of an acid catalyst.

(In the formula, all symbols have the same meaning as described above.)
Examples of the acid catalyst in this reaction include trifluoroacetic acid.
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours 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。）
この反応における溶媒としては、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。 The salt represented by the formula (I4A-a) is produced, for example, by reacting the salt represented by the formula (I4A-b) with the compound represented by the formula (I4A-c) in a solvent. Can do.

(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

Examples of the compound represented by the formula (I4A-c) include compounds represented by the following, and can be produced by the method described in JP2013-54344A.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における溶媒としては、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。 The salt represented by the formula (I4A-b) can be obtained by reacting the salt represented by the formula (I4A-d) with the compound represented by the formula (I2-e) in a solvent. it can.

(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours 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。）
この反応における酸触媒としては、トリフルオロ酢酸等が挙げられる。
この反応における溶媒としては、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。
式（Ｉ４Ａ−ｅ）で表される塩は、例えば、以下で表される塩などが挙げられ、特開２０１１−０４６６９４号公報に記載された方法で製造することができる。

The salt represented by the formula (I4A-d) can be produced, for example, by hydrolyzing the salt represented by the formula (I4A-e) in a solvent in the presence of an acid catalyst.

(In the formula, all symbols have the same meaning as described above.)
Examples of the acid catalyst in this reaction include trifluoroacetic acid.
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.
Examples of the salt represented by the formula (I4A-e) include salts represented by the following, and can be produced by the method described in JP2011-046694A.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における酸触媒としては、トリフルオロ酢酸等が挙げられる。
この反応における溶媒としては、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。 In the salt (I), a salt in which X ¹ is —O— (a salt represented by the formula (I5)) is, for example, a salt represented by the formula (I5-a) in the presence of an acid catalyst. It can be produced by hydrolysis in it.

(In the formula, all symbols have the same meaning as described above.)
Examples of the acid catalyst in this reaction include trifluoroacetic acid.
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours 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。）
この反応における塩基としては、水酸化カリウム等が挙げられる。
この反応における溶媒としては、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 salt represented by the formula (I5-a) is obtained by reacting the salt represented by the formula (I3-d) with the compound represented by the formula (I3-c) in a solvent under a base catalyst. Can be obtained.

(In the formula, all symbols have the same meaning as described above.)
Examples of the base in this reaction include potassium hydroxide.
Examples of the solvent in this reaction include acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

<Acid generator>
The acid generator of the present invention is an acid generator containing a salt (I). The salt (I) may be used alone or in combination of two or more.
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 the salt (I). An acid generator (B) may be used independently and may be used in combination of 2 or more type.

  The acid generator (B) may be either nonionic or ionic. Examples of the nonionic acid generator include sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (for example, disulfone, Ketosulfone, sulfonyldiazomethane) and the like. Typical examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, and iodonium salts). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  As the acid generator (B), JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, Kaisho 62-153853, JP 63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712, etc. The compound which generate | occur | produces an acid by the radiation as described in 1 can be used. Moreover, you may use the compound manufactured by the well-known method. Two or more acid generators (B) may be used in combination.

［式（Ｂ１）中、
Ｑ^ｂ１及びＱ^ｂ２は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^ｂ１は、炭素数１〜２４の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−Ｓ（Ｏ）_２−又は−ＣＯ−に置き換わっていてもよい。
Ｚ１^＋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)”. However, 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 divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and is included in the alicyclic hydrocarbon group − CH ₂ — may be replaced by —O—, —S (O) ₂ —, or —CO—.
Z1 ⁺ represents an organic cation. ]

^Examples of the perfluoroalkyl group 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 etc. are mentioned.
Q ^b1 and Q ^b2 are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these It may be a group formed by combining two or more of the groups.
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, 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced by —O— or —CO— include, for example, formula (b1-1) to formula (b1-3) Or a group represented by any of the above. In the groups represented by formula (b1-1) to formula (b1-3) and the groups represented by formula (b1-4) to formula (b1-11) as specific examples thereof, * represents − Represents a bond with Y.

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

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

In the groups represented by formula (b1-1) to formula (b1-3), when —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O— or —CO—, the carbon before the replacement The number is the carbon number of the saturated hydrocarbon group.
Examples of the divalent saturated hydrocarbon group include the same divalent saturated hydrocarbon group of L ^b1.

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—.

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

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

[In the formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In formula (b1-5),
^Lb9 represents a C1-C20 bivalent saturated hydrocarbon group.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b9 and L ^b10 is 20 or less.
In formula (b1-6),
L ^b11 represents a C1-C21 divalent saturated hydrocarbon group.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b11 and L ^b12 is 21 or less.
In formula (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^{b13 to} L ^b15 is 19 or less.
In formula (b1-8),
L ^b16 represents a C1-C18 divalent saturated hydrocarbon group.
L ^b17 represents a C1- ^C18 divalent saturated hydrocarbon group.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^{b16 to} L ^b18 is 19 or less. ]

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a C 1-8 divalent saturated hydrocarbon group.
L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 is preferably a ^C 1-6 divalent saturated hydrocarbon group.
L ^b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent 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２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b20は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる−ＣＨ₂−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b19及びＬ^b20の合計炭素数は２３以下である。
式（ｂ１−１０）中、
Ｌ^b21は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b22は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表す。
Ｌ^b23は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる−ＣＨ₂−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b21、Ｌ^b22及びＬ^b23の合計炭素数は２１以下である。
式（ｂ１−１１）中、
Ｌ^b24は、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b25は、炭素数１〜２１の２価の飽和炭化水素基を表す。
Ｌ^b26は、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる−ＣＨ₂−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b24、Ｌ^b25及びＬ^b26の合計炭素数は２１以下である。 Examples of the group represented by formula (b1-3) include groups represented by formula (b1-9) to formula (b1-11), respectively.

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

  In addition, in the group represented by the formula (b1-11) to the group represented by the formula (b1-9), when the hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the group is replaced. The previous carbon number is defined as the carbon number of the saturated hydrocarbon group.

  Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

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

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

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

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

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

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

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

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

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

Examples of the alicyclic hydrocarbon group represented by Y include 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 by —O—, —S (O) ₂ — or —CO—, the number may be one, or two or more. Good. Examples of such a group include groups represented by formula (Y12) to formula (Y35), formula (Y39), and formula (Y40).

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

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

Examples of the substituent for the methyl group represented by Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, or-( CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic group having 6 to 18 carbon atoms). Represents a hydrocarbon group, and ja represents an integer of 0 to 4).
Examples of the substituent for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms which may be substituted with a hydroxy group, and an alicyclic group having 3 to 16 carbon atoms. A hydrocarbon group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, a glycidyloxy group or-( CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic group having 6 to 18 carbon atoms). Represents a hydrocarbon group, and ja represents an integer of 0 to 4).

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, an adamantyl group, and the like.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. , Aryl groups such as biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the alkyl group 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.
Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of Y include the following.

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

  As the anion in the salt represented by the formula (B1), an anion represented by the formula (B1-A-1) to the formula (B1-A-55) [hereinafter referred to as an anion (B1-A -1) ". ] 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) to Formula (B1-A-40), Formula (B1-A-47) to Formula (B1-A-55) An anion is more preferable.

ここでＲ^ｉ２〜Ｒ^ｉ７は、互いに独立に、例えば、炭素数１〜４のアルキル基、好ましくはメチル基又はエチル基である。Ｒ^ｉ８は、例えば、炭素数１〜１２の鎖式炭化水素基、好ましくは炭素数１〜４のアルキル基、炭素数５〜１２の脂環式炭化水素基又はこれらを組合せることにより形成される基、より好ましくはメチル基、エチル基、シクロヘキシル基又はアダマンチル基である。Ｌ^Ａ４１は、単結合又は炭素数１〜４のアルカンジイル基である。
Ｑ^ｂ１及びＱ^ｂ２は、上記と同じ意味を表す。
式（Ｂ１）で表される塩におけるアニオンとしては、具体的には、特開２０１０−２０４６４６号公報に記載されたアニオンが挙げられる。

Here, R ^{i2 to} R ⁱ⁷ are independently of each other, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is formed by, for example, a chain hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. More preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L ^A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ^b1 and Q ^b2 represent the same meaning as described above.
Specific examples of the anion in the salt represented by the formula (B1) include anions described in JP 2010-204646 A.

Preferable examples of the anion in the salt represented by the formula (B1) include anions each represented by the formula (B1a-1) to the formula (B1a-34).

  Especially, Formula (B1a-1)-Formula (B1a-3) and Formula (B1a-7)-Formula (B1a-16), Formula (B1a-18), Formula (B1a-19), Formula (B1a-22) ) To (B1a-30) are preferred.

Examples of the organic cation of Z1 ⁺ include an organic onium cation, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an arylsulfonium cation is more preferable.
Examples of Z1 ⁺ in the formula (B1) are the same as those of the cation (I) in the salt (I).

  The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. The acid generator (B) is preferably a formula (B1a-1) to a formula (B1a-3) and a formula (B1a-7) to a formula (B1a-16), a formula (B1a-18), a formula (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).

As the acid generator (B), those represented by formulas (B1-1) to (B1-48) are preferably exemplified. Among them, those containing an arylsulfonium cation are preferable. Formula (B1-1) to Formula (B1-3), Formula (B1-5) to Formula (B1-7), Formula (B1-11) to Formula (B1-14) ), Formula (B1-20) to formula (B1-26), formula (B1-29), and formula (B1-31) to formula (B1-48) are particularly preferable.

  In the resist composition of the present invention, the content of the acid generator is preferably 1 part by mass or more and 40 parts by mass or less, more preferably 3 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the resin (A). It is. The resist composition of the present invention may contain one kind of acid generator (B) alone, or may contain plural kinds.

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

<Resist composition>
The resist composition of the present invention contains an acid generator containing salt (I) and a resin having an acid labile group (hereinafter sometimes referred to as “resin (A)”). Here, the “acid labile group” has a leaving group, the leaving group is eliminated by contact with an acid, and the structural unit has a hydrophilic group (for example, a hydroxy group or a carboxy group). This means a group that converts to a unit.
The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid having a lower acidity than an acid generated from an acid generator (hereinafter sometimes referred to as “quencher (C)”). And a solvent (hereinafter sometimes referred to as “solvent (E)”).

<Resin (A)>
The resin (A) has a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a1)”). The resin (A) preferably further contains a structural unit other than the structural unit (a1). As the structural unit other than the structural unit (a1), a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”), structural unit (a1), and structural unit (s). Structural unit (for example, a structural unit having a halogen atom described later (hereinafter sometimes referred to as “structural unit (a4)”), a structural unit having a non-elimination hydrocarbon group described later (hereinafter referred to as “structural unit (a5)”) And other structural units derived from monomers known in the art.

［式（１）中、Ｒ^a1〜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の脂環式炭化水素基を形成する。
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の複素環基を形成し、該炭化水素基及び該複素環基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｓ−で置き換わってもよい。
Ｘ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 to} R ^a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination of these, or R ^a1 and R ^a2 are bonded to each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
ma and na each independently represents 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. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and are included in the hydrocarbon group and the heterocyclic group − CH ₂ — 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が互いに結合して脂環式炭化水素基を形成する場合の−Ｃ（Ｒ^a1）（Ｒ^a2）（Ｒ^a3）としては、下記の基が挙げられる。脂環式炭化水素基は、好ましくは炭素数３〜１２である。＊は−Ｏ−との結合手を表す。

^Examples of the alkyl group in R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group in R ^{a1 to} R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bond). Carbon number of the alicyclic hydrocarbon group of R ^{a1 to} R ^a3 is preferably 3 to 16.

Examples of the group 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.
Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) when R ^a1 and R ^a2 are bonded to each other to form an alicyclic hydrocarbon group include the following groups. The alicyclic hydrocarbon group 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 the hydrocarbon group in R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same groups as those described for R ^{a1 to} R ^a3 .
The aromatic hydrocarbon group includes phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl. Group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl group, and the like.
Examples of the combined group include a group in which the above-described alkyl group and alicyclic hydrocarbon group are combined (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, and an aryl-cyclohexyl group such as a phenylcyclohexyl group. .
^{Examples of} the heterocyclic group formed together with the carbon atom to which R ^{a2 ′} and R ^{a3 ′} are bonded to each other and X, and X, include the following groups. * Represents a bond.

Of R ^{a1 ′} and R ^{a2 ′} , at least one is preferably a hydrogen atom.
na ′ is preferably 0.

Examples of the group (1) include the following groups.
In the formula (1), R ^{a1 to} R ^a3 are alkyl groups, ma = 0, and na = 1. As the group, a tert-butoxycarbonyl group is preferable.
In formula (1), R ^a1 and R ^a2 together with the carbon atom to which they are bonded form an adamantyl group, R ^a3 is an alkyl group, ma = 0 and na = 1 .
In the formula (1), R ^a1 and R ^a2 are each independently an alkyl group, R ^a3 is an adamantyl group, ma = 0, and na = 1.
Specific examples of the group (1) include the following groups. * Represents a bond.

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

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

［式（ａ１−０）、式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a01、Ｌ^ａ１及びＬ^ａ２は、それぞれ独立に、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ１−ＣＯ−Ｏ−を表し、ｋ１は１〜７のいずれかの整数を表し、＊は−ＣＯ−との結合手を表す。
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 the (meth) acrylic monomer having the group (1) is preferably a structural unit represented by the 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) in some cases). 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 any integer of 1 to 7, and * represents It 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 an integer of 0 to 14.
n1 represents any integer of 0 to 10.
n1 ′ represents any 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— (where k01 is preferably an integer of 1 to 4, more preferably Is 1.), more preferably an oxygen atom.
Examples of the alkyl group, alicyclic hydrocarbon group, and a combination thereof in R ^a02 , R ^a03 , R ^a04 , R ^a6, and R ^a7 are the same as those ^exemplified for R ^{a1 to} R ^a3 in formula (1). Groups.
Carbon number of the alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 is preferably 5 to 12, more preferably 5 to 10.
The group in which the alkyl group and the alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in combination of the alkyl group and the alicyclic hydrocarbon group.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group.
The carbon number of the alkyl group in R ^a6 and R ^a7 is preferably 1 to 6, more preferably a methyl group, an ethyl group, or an isopropyl group, and still more preferably an ethyl group or an isopropyl group.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As the structural unit (a1-0), for example, R ^a01 in the structural unit represented by any of the formulas (a1-0-1) to (a1-0-12) and the structural unit (a1-0) Examples include a structural unit in which a corresponding methyl group is replaced with a hydrogen atom, and a structural unit represented by any one of formulas (a1-0-1) to (a1-0-10) is preferable.

As a structural unit (a1-1), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Especially, the methyl group corresponding to R ^a4 in the structural unit represented by any one of the formulas (a1-1-1) to (a1-1-4) and the structural unit (a1-1) was replaced with a hydrogen atom. A structural unit is preferable, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferable.

The structural unit (a1-2) corresponds to the structural unit represented by any one of the formulas (a1-2-1) to (a1-2-6) and R ^a5 in the structural unit (a1-2). Examples include a structural unit in which a methyl group is replaced with a hydrogen atom, and the formula (a1-2-2), the formula (a1-2-5), and the formula (a1-2-6) are preferable.

  When the resin (A) includes the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is the total structure of the resin (A). It is 10-95 mol% normally with respect to a unit, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%, More preferably, it is 25-70 mol%, 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。］ Examples of the structural unit having the group (2) in the structural unit (a1) include a structural unit represented by the 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 An oxy group or a methacryloyloxy group is represented.
la represents an integer of 0 to 4. When la is 2 or more, the plurality of R ^a33 may be the same as or different from each other.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 may represent a hydrocarbon group having 1 to 20 carbon atoms, R ^a35 and R ^a36 are bonded to each other Together with —C—O— to which they are bonded to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group is — O- or -S- may be substituted. ]

^Examples of the alkyl group in R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
Examples of the halogen atom in R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, and a bromine atom.
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. Can be mentioned.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group. Especially, a C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further more preferable.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
As the hydrocarbon group for R ^a34, R ^a35 and R ^a36, an alkyl group, an alicyclic hydrocarbon group, aromatic hydrocarbon group, and include groups formed by combining these, alkyl groups and alicyclic hydrocarbon groups Examples thereof include the same groups as the alkyl group and the alicyclic hydrocarbon group in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 .
The aromatic hydrocarbon group includes phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl. Group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl group, and the like.
Examples of the combined group include a group in which the above-described alkyl group and alicyclic hydrocarbon group are combined (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, and an aryl-cyclohexyl group such as a phenylcyclohexyl group. .
In particular, as R ^a36 , 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 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 further preferably a methoxy group.
As la, 0 or 1 is preferable, and 0 is more preferable.
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 for 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 thereof. It is 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} ) -O-R a36 in the structural unit (a1-4) is contacted with an acid (e.g. p- toluenesulfonic acid) to form a hydroxy group.

As a structural unit (a1-4), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Preferably, hydrogen atom corresponding to ^{R a32} in equation (a1-4-1) represented respectively to Formula (a1-4-8) structural units and structural units (a1-4) is replaced by a methyl group structure And more preferably, structural units represented by formula (a1-4-1) to formula (a1-4-5), respectively.

  When resin (A) has a structural unit (a1-4), it is preferable that the content rate is 10-95 mol% with respect to the sum total of all the structural units of resin (A), 15-90 It is more preferably mol%, more preferably 20 to 85 mol%, still more preferably 20 to 70 mol%, still more preferably 20 to 60 mol%.

式（ａ１−５）中、
Ｒ^a8は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
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。 Examples of the structural unit derived from the (meth) acrylic monomer having the group (2) include a structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”). It is done.

In formula (a1-5),
R ^a8 represents a C 1-6 alkyl group optionally having 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 to L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent —O— or —S—.
s1 represents any integer of 1 to 3.
s1 ′ represents any integer of 0 to 3.

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, fluoromethyl and trifluoromethyl. Groups.
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.
Of L ⁵² and L ⁵³ , one is preferably —O— and the other is preferably —S—.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

As a structural unit (a1-5), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-611117 is mentioned, for example. Among these, structural units each represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and are represented by formula (a1-5-1) or formula (a1-5-2). A structural unit is more preferable.

  When resin (A) has a structural unit (a1-5), the content rate is preferable 1-50 mol% with respect to all the structural units of resin (A), and 3-45 mol% is more preferable. 5 to 40 mol% is more preferable, and 5 to 30 mol% is even more preferable.

In addition, examples of the structural unit (a1) include the following structural units.

  When the resin (A) includes structural units such as (a1-3-1) to (a1-3-7), the content is 10 to 10% with respect to all the structural units of the resin (A). 95 mol% is preferable, 15-90 mol% is more preferable, 20-85 mol% is further more preferable, 20-70 mol% is still more preferable, 20-60 mol% is especially preferable.

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

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When a resist pattern is produced from the resist composition of the present invention, when a high energy beam such as a KrF excimer laser (248 nm), an electron beam or EUV (ultra-ultraviolet light) is used as an exposure light source, the structural unit (a2) It is preferable to use the structural unit (a2) having a phenolic hydroxy group. In the case of using an ArF excimer laser (193 nm) or the like, the structural unit (a2) having an alcoholic hydroxy group is preferable as the structural unit (a2), and the structural unit (a2-1) described later is more used. preferable. As a structural unit (a2), 1 type may be included independently and 2 or more types may be included.

［式（ａ２−Ａ）中、
Ｒ^a50は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^a51は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアルキルカルボニル基、炭素数２〜４のアルキルカルボニルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
Ａ^a50は、単結合又は^＊−Ｘ^a51−（Ａ^a52−Ｘ^a52）_nｂ−を表し、＊は−Ｒ^a50が結合する炭素原子との結合手を表す。
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。］ Examples of the structural unit having a phenolic hydroxy group in the structural unit (a2) include a structural unit represented by the 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 An oxy group or a methacryloyloxy group is represented.
A ^a50 represents a single bond or ^* —X ^a51 — (A ^a52 —X ^a52 ) _nb —, and * represents a bond to the carbon atom to which —R ^a50 is bonded.
A ^a52 each 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 of 0 to 4. When mb is any integer of 2 or more, the plurality of ^Ra51s may be the same as or different from each other. ]

^Examples of the halogen atom for R ^a50 include a fluorine atom, a chlorine atom and a bromine atom.
^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in 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 perfluorohexyl Groups.
R ^a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
^Examples of the alkyl group for R ^a51 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group.
^Examples of the alkoxy group for R ^a51 include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. A C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is more preferable.
^Examples of the alkylcarbonyl group for R ^a51 include an acetyl group, a propionyl group, and a butyryl group.
^Examples of the alkylcarbonyloxy group for R ^a51 include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
R ^a51 is preferably a methyl group.

^* -X ^a51- (A ^a52 -X ^a52 ) _nb- includes ^* -O-, ^* -CO-O-, ^* -O-CO-, ^* -CO-O-A ^a52 -CO-O-, ^* —O—CO—A ^a52 —O—, ^* —O—A ^a52 —CO—O—, ^* —CO—O—A ^a52 —O—CO—, ^* —O—CO—A ^a52 —O—CO -. Of these, ^* —CO—O—, ^* —CO—O—A ^a52 —CO—O— or ^* —O—A ^a52 —CO—O— is preferable.

Examples of alkanediyl groups include 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 and 2 -Methylbutane-1,4-diyl group etc. are mentioned.
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—, and is preferably a single bond, ^* —CO—O— or ^* —CO—O—CH. _2- CO-O- is more preferable, and a single bond or ^* -CO-O- is more preferable.

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, and more preferably bonded to the p-position.

  Examples of the structural unit (a2-A) include structural units derived from monomers described in JP2010-204634A and JP2012-12577A.

As the structural unit (a2-A), structural units represented by formula (a2-2-1) to formula (a2-2-4) and formula (a2-2-1) to formula (a2-2-2) In the structural unit represented by 4), a structural unit in which a methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom can be mentioned. The structural unit (a2-A) is represented by the structural unit represented by the formula (a2-2-1), the structural unit represented by the formula (a2-2-3), and the formula (a2-2-1). In the structural unit represented by formula (a2-2-3), the methyl group corresponding to R ^a50 in the structural unit (a2-A) is preferably a structural unit in which a hydrogen atom is replaced.

When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 5 to 80 mol%, more preferably based on all structural units. It is 10-70 mol%, More preferably, it is 15-65 mol%, More preferably, it is 20-65 mol%.
The structural unit (a2-A) can be included in the resin (A), for example, by treating a resin containing the structural unit (a1-4) with an acid such as p-toluenesulfonic acid. Moreover, after superposing | polymerizing using acetoxy styrene etc., a structural unit (a2-A) can be included in resin (A) by processing with alkalis, 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。 Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include a structural unit represented by the 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 of 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 of 0 to 10.

In the formula (a2-1), L ^a3 is preferably —O—, —O— (CH ₂ ) _f1 —CO—O— (wherein f1 represents an integer of 1 to 4). More preferably, it is —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 an integer of 0 to 3, more preferably 0 or 1.

As a structural unit (a2-1), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. A structural unit represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferred, and any one of formula (a2-1-1) to formula (a2-1-4) The structural unit represented is more preferable, and the structural unit represented by the formula (a2-1-1) or the formula (a2-1-3) is more preferable.

  When resin (A) contains a structural unit (a2-1), the content rate is 1-45 mol% normally with respect to all the structural units of resin (A), Preferably it is 1-40 mol%. Yes, more preferably 1 to 35 mol%, still more preferably 2 to 20 mol%, and even more preferably 2 to 10 mol%.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. But you can. Preferably, 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)) is used.

［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もよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^ａ２１は炭素数１〜４の脂肪族炭化水素基を表す。
Ｒ^ａ２２、Ｒ^ａ２３及びＲ^ａ２５は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は０〜５のいずれかの整数を表す。
ｑ１は、０〜３のいずれかの整数を表す。
ｒ１は、０〜３のいずれかの整数を表す。
ｗ１は、０〜８のいずれかの整数を表す。
ｐ１、ｑ１、ｒ１及び／又はｗ１が２以上のとき、複数のＲ^ａ２１、Ｒ^ａ２２、Ｒ^ａ２３及び／又はＲ^ａ２５は互いに同一であってもよく、異なっていてもよい。］ The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). These 1 type may be contained independently and 2 or more types 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 any integer of 1 to 7). Represents a group.
L ^a7 is —O—, ^* —O—L ^a8 —O—, ^* —O—L ^a8 —CO—O—, ^* —O—L ^a8 —CO—O—L ^a9 —CO—O— or ^* —O—L ^a8 —O—CO—L ^a9 —O— is represented.
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.
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 of 0 to 5.
q1 represents any integer of 0 to 3.
r1 represents any integer of 0 to 3.
w1 represents an integer of 0 to 8.
When p1, q1, r1 and / or w1 is 2 or more, a plurality of R ^a21 , R ^a22 , R ^a23 and / or R ^a25 may be the same as or different from each other. ]

Examples of the aliphatic hydrocarbon group in 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. It is done.
Examples of the halogen atom for R ^a24 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
^Examples of the alkyl group in R ^a24 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group, and preferably have 1 to 4 carbon atoms. And more preferably a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom in R ^a24 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 perfluoro group. A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group, etc. are mentioned.

^Examples of the alkanediyl group in ^La8 and ^La9 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a 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, etc. are mentioned.

In the formula (a3-1) to the formula (a3-3), L ^{a4 to} L ^a6 are each independently, preferably —O— or * —O— (CH ₂ ) _k3 —CO—O—, Is a group of any one of 1 to 4, more preferably —O— and * —O—CH ₂ —CO—O—, still 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, and still more preferably a hydrogen atom or a methyl group. It is.
R ^a25 is preferably a carboxy group, a cyano group, or a methyl group.
L ^a7 is preferably —O— or ^* —O—L ^a8 —CO—O—, more preferably —O—, —O—CH ₂ —CO—O— or —O—C ₂ H ₄ —. CO-O-.
w1 is preferably an integer of 0 to 2, and more preferably 0 or 1.
In particular, the formula (a3-4) is preferably the formula (a3-4) ′.

(Wherein R ^a24 and L ^a7 represent the same meaning as described above.)

As the structural unit (a3), a monomer derived from JP2010-204646, a monomer described in JP2000-122294A, a structure derived from a monomer described in JP2012-41274A Units are listed. As the structural unit (a3), the formula (a3-1-1), the formula (a3-1-2), the formula (a3-2-1), the formula (a3-2-2), the formula (a3-3) 1), a structural unit represented by any one of formula (a3-3-2) and formula (a3-4-1) to formula (a3-4-12), and the structural unit represented by formula (a3-1) ) To a structural unit in which a methyl group corresponding to R ^a18 , R ^a19 , R ^a20 and R ^a24 in formula (a3-4) is replaced with a hydrogen atom.

When the resin (A) includes the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). More preferably, it is 10-60 mol%.
Moreover, the content rate of a structural unit (a3-1), a structural unit (a3-2), a structural unit (a3-3), or a structural unit (a3-4) is respectively with respect to all the structural units of resin (A). 5 to 60 mol% is preferable, 5 to 50 mol% is more preferable, and 10 to 50 mol% is more preferable.

［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)>
Examples of the structural unit (a4) include the following structural units.

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

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式炭化水素基とを組み合わせることにより形成される基が挙げられ、−アルカンジイル基−脂環式炭化水素基、−脂環式炭化水素基−アルキル基、−アルカンジイル基−脂環式炭化水素基−アルキル基等が挙げられる。 The chain hydrocarbon group includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl. Can be mentioned. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups: And polycyclic alicyclic hydrocarbon groups such as (* represents a bond).

Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, -alkanediyl group- An alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic hydrocarbon group-alkyl group and the like can be mentioned.

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

[In the formula (a4-0),
R ⁵ 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.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

As the alkanediyl group in L ^4a, a linear alkanediyl group such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, an ethane-1,1-diyl group, Examples include branched alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group. It is done.

As the perfluoroalkanediyl group in L ^3a , a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane -2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane -2,2-diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane -1,7-diyl group, perfluorohe Tan-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluoro Examples include an octane-3,3-diyl group and a perfluorooctane-4,4-diyl group.
^Examples of the perfluorocycloalkanediyl group in L ^3a include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

L ^4a is preferably a single bond, a methylene group or an ethylene group, and 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 in which the methyl group corresponding to R ⁵ in the structural unit shown below and the structural unit (a4-0) in the structural unit shown below is replaced with a hydrogen atom.

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

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

[In the formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a C1-C20 saturated hydrocarbon group which may have a substituent, and —CH ₂ — contained in the saturated hydrocarbon group is replaced by —O— or —CO—. May be.
A ^a41 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the 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 a ^C 1-5 divalent saturated hydrocarbon group which may have a substituent.
A ^a43 represents a ^C1-C5 divalent aliphatic hydrocarbon group which may have a single bond or a substituent.
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 is a bond with —O—CO—R ^a42 . ]

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

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式炭化水素基とを組み合わせることにより形成される基が挙げられ、−アルカンジイル基−脂環式炭化水素基、−脂環式炭化水素基−アルキル基、−アルカンジイル基−脂環式炭化水素基−アルキル基等が挙げられる。
The chain hydrocarbon group includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl. Can be mentioned. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups: And polycyclic alicyclic hydrocarbon groups such as (* represents a bond).

Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, -alkanediyl group- An alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic hydrocarbon group-alkyl group and the like can be mentioned.

［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。）を表す。
Ａ^a45は、ハロゲン原子を有していてもよい炭素数１〜１７の脂肪族炭化水素基を表す。
＊は結合手を表す。］
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の脂肪族炭化水素基を表す。 ^Examples of the substituent that R ^a42 may have include a halogen atom and a group represented by the formula (a-g3). As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, Preferably it is 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 to R ^a42 ).
A ^a45 represents an aliphatic 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 aliphatic hydrocarbon group having at least one halogen atom.

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

R ^a42 is preferably a saturated hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or a saturated hydrocarbon group having a group represented by the 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 1 to 1 carbon atoms. 6 perfluoroalkyl group, particularly preferably a C 1-3 perfluoroalkyl group. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.
When R ^a42 is a saturated hydrocarbon group having a group represented by the formula (a-g3), including the number of carbons contained in the group represented by the formula (a-g3), the total carbon of R ^a42 The number is preferably 15 or less, and more preferably 12 or less. When it has a group represented by the formula (a-g3) as a substituent, the number is preferably 1.

［式（ａ−ｇ２）中、
Ａ^a46は、ハロゲン原子を有していてもよい炭素数１〜１７の２価の脂肪族炭化水素基を表す。
Ｘ^a44は、＊−Ｏ−ＣＯ−又は＊−ＣＯ−Ｏ−を表す（＊はＡ^a46との結合手を表す。）を表す。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１〜１７の脂肪族炭化水素基を表す。
ただし、Ａ^a46、Ａ^a47及びＸ^a44の炭素数の合計は１８以下であり、Ａ^a46及びＡ^a47のうち、少なくとも一方は、少なくとも１つのハロゲン原子を有する。
＊はカルボニル基との結合手を表す。］ When R ^a42 is a saturated hydrocarbon group having a group represented by the formula (a-g3), R ^a42 is more preferably a group represented by the formula (a-g2).

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

1-6 are preferable and, as for carbon number of the aliphatic hydrocarbon group of ^Aa46 , 1-3 are more preferable.
4-15 are preferable, as for carbon number of the aliphatic hydrocarbon group of A ^<a47> , 5-12 are more preferable, and A ^<a47> has a more preferable cyclohexyl group or an adamantyl group.

A preferable structure of the group represented by the formula (a-g2) is the following structure (* is a bond with a carbonyl group).

As the alkanediyl group in ^Aa41 , a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group Linear alkanediyl group such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples include branched alkanediyl groups such as 2-methylbutane-1,4-diyl group.
^Examples of the substituent in 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 group represented by A ^a42 , A ^a43 and A ^{a44 in} the group represented by the formula (a-g1) includes a linear or branched alkanediyl group and a monocyclic divalent alicyclic group. Examples thereof include a hydrocarbon group and a group formed by combining an alkanediyl group and a divalent alicyclic hydrocarbon group. 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, Examples include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
^Examples of the substituent of the divalent saturated hydrocarbon group 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 0.

In the group represented by the formula (a-g2), ^{examples of the} group in which X ^a42 is —O—, ^—CO— , ^—CO —O— or —O—CO— include the following groups. In the following examples, * and ** each represent a bond, and ** is a bond with —O—CO—R ^a42 .

As the structural unit represented by the formula (a4-1), a methyl group corresponding to R ^a41 in the structural unit shown below and the structural unit represented by the formula (a4-1) in the following structural unit is a hydrogen atom. Examples include structural units that have been replaced.

［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 the formula (a4-1), a structural unit represented by the formula (a4-2) is preferable.

[In the 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.
However, the upper limit of the total number of carbon atoms of L ⁴⁴ and R ^f6 are 21. ]

Alkanediyl group of L ⁴⁴ include the same groups as those exemplified with L ^4a.
Examples of the saturated hydrocarbon group for R ^f6 include the same groups as those exemplified for R ^a42 .
As the alkanediyl group for L ^44, an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.

Examples of the structural unit represented by formula (a4-2) include structural units represented by formula (a4-1-1) to formula (a4-1-11), respectively. A structural unit in which a methyl group corresponding to R ^f5 in the structural unit (a4-2) is replaced with a hydrogen atom is also exemplified 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。）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。］ As the structural unit (a4), a structural unit represented by formula (a4-3) can be given.

[In the 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 to A ^f13 ).
A ^f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms 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 in L ⁵ include the same groups as those exemplified for the alkanediyl group of L ^4a .

The divalent saturated hydrocarbon group which may have a fluorine atom in A ^f13 preferably has a divalent aliphatic saturated hydrocarbon group which may have a fluorine atom and a fluorine atom. A divalent alicyclic saturated hydrocarbon group, more preferably a perfluoroalkanediyl group.
Examples of the divalent aliphatic hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; difluoromethylene group, perfluoroethylene group, perfluoro Examples thereof include perfluoroalkanediyl groups such as propanediyl group, perfluorobutanediyl group and perfluoropentanediyl group.
The divalent alicyclic hydrocarbon group which may have a fluorine atom may be monocyclic or polycyclic. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

As the saturated hydrocarbon group for A ^{f14 and} the saturated hydrocarbon group which may have a fluorine atom, the same groups as those exemplified for R ^a42 can be mentioned. 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 of 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group and perfluorooctyl group Alkyl group, cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, Fluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyl dimethyl group, norbornyl group, norbornylmethyl group, perfluoro adamantyl group, a perfluoroalkyl adamantylmethyl group and the like are preferable.

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

Examples of the structural unit represented by formula (a4-3) include structural units represented by formula (a4-1′-1) to formula (a4-1′-11), respectively. A structural unit in which a methyl group corresponding to R ^f7 in the structural unit (a4-3) is replaced with a hydrogen atom is also exemplified 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。］ Examples of the structural unit (a4) include a structural unit represented by the formula (a4-4).

[In the 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 represents an integer of 1 to 6.
R ^f22 represents a C 1-10 saturated hydrocarbon group having a fluorine atom. ]

^Examples of the saturated hydrocarbon group for R ^f22 include the same saturated hydrocarbon groups represented by R ^a42 . R ^f22 is preferably a ^C 1-10 alkyl group having a fluorine atom or a C 1-10 alicyclic hydrocarbon group having a fluorine atom, more preferably a C 1-10 alkyl group having a fluorine atom. Preferably, the C1-C6 alkyl group which has a fluorine atom is further more preferable.

In formula (A4-4), as the _{^{A f21, - (CH 2)}} j1 - , more preferably an ethylene group or a methylene group, more preferably a methylene group.

As the structural unit represented by the formula (a4-4), for example, in the following structural unit and the structural unit represented by the following formula, a methyl group corresponding to R ^f21 in the structural unit (a4-4) is hydrogen. Examples include structural units replaced by atoms.

  When the resin (A) has a structural unit (a4), the content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, based on all structural units of the resin (A). More preferably, it is 10 mol%.

［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 the non-elimination hydrocarbon group included in the structural unit (a5) include groups having a linear, branched, or cyclic hydrocarbon group. Among these, the structural unit (a5) is preferably a group having an alicyclic hydrocarbon group.
As a structural unit (a5), the structural unit represented by a formula (a5-1) is mentioned, for example.

[In the formula (a5-1),
R ⁵¹ 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 by —O— or —CO—. . ]

The alicyclic hydrocarbon group for R ⁵² may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include 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 an ethylhexyl group, are mentioned.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group.

Examples of the divalent saturated hydrocarbon group for L ⁵⁵ include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent chain saturated hydrocarbon group. .
Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ⁵⁵ is replaced by —O— or —CO— include those represented by formulas (L1-1) to (L1-4): And the group represented. In the following formula, * represents a bond with an oxygen atom.

In formula (L1-1),
X ^x1 represents * —O—CO— or * —CO—O— (* represents a bond to L ^x1 ).
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.

In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.

In formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^x5 , L ^x6 and L ^x7 is 15 or less.

In formula (L1-4),
L ^x8 and L ^x9 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic saturated 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 divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond.
L ^x3 is preferably a C 1-8 divalent aliphatic saturated hydrocarbon group.
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 divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, 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 aliphatic saturated 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 aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

As group represented by a formula (L1-1), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-2), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-3), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-4), the bivalent group shown below is mentioned, for example.

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

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

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

When the resin (A) has the structural unit (a5), the content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, based on all structural units of the resin (A). More preferred is ˜15 mol%.

<Structural unit (II)>
The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as “structural unit (II)”). Is a structural unit described in JP-A-2016-79235, which is a structural unit having a sulfonate group or 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 there is.

［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。］ The structural unit having a sulfonate group or carboxylate group and an organic cation in the side chain is preferably a structural unit represented by the 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 by —O—, —S— or —CO—. The 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 or carboxylate groups.
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. ]

Examples of the halogen atom represented by R ^III3 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^III3 , an alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 and The same can be mentioned.
Examples of the alkanediyl group having 1 to 8 carbon atoms represented by A ^x1 include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, and a 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. Can be mentioned.

Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by ^XIII3 include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. These may be combined.
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 , Linear alkanediyl groups such as dodecane-1,12-diyl group; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group Branched alkanediyl groups such as pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 , 4-diyl group, Cycloalkanediyl group such as looctane-1,5-diyl group; norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group Bivalent polycyclic alicyclic saturated hydrocarbon groups and the like.

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

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

Examples of the organic cation represented by ZA ⁺ include the same cation (I) as in salt (I).

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

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

^{Examples of} the C 1-6 perfluoroalkyl group represented by R ^III2 , R ^III4 , Q ^a and Q ^b include the same as the C 1-6 perfluoroalkyl group represented by Q ^b1 described above. .

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

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

Examples of the saturated hydrocarbon group 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, Examples thereof include linear or branched alkyl groups such as heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group.
Examples of the divalent saturated hydrocarbon group represented by X ^I2, are the same as those of the divalent saturated hydrocarbon group 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、互いに独立に、１又は２を表す。］ As the structural unit represented by the formula (II-2-A-1), a structural unit represented by the formula (II-2-A-2) is preferable.

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

Examples of the structural unit represented by the formula (II-2-A ′) include the following structural units and the structural units described in International Publication No. 2012/050015. ZA ⁺ represents an organic cation.

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

[In the formula (II-1-1),
A ^II1 represents a single bond or a divalent linking group.
R ^II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^II2 and R ^II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and R ^II2 and R ^II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
R ^II4 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
A ⁻ represents an organic anion. ]
Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ^II1 include a phenylene group and a naphthylene group.
Examples of the hydrocarbon group represented by R ^II2 and R ^II3 include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the halogen atom represented by R ^II4 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^II4 , 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 the divalent linking group represented by A ^II1 include 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. Specifically, the same thing as a C1-C18 bivalent saturated hydrocarbon group represented by ^XIII3 is mentioned.

Examples of the structural unit containing a cation in formula (II-1-1) include the structural units represented below.

A ^- The organic anion represented by a sulfonic acid anion, sulfonyl imide anion, methide anion and a carboxylate anion, and the like. A ^- organic anion represented by the sulfonate anion are preferable, and as a sulfonate anion, more preferably an anion contained in the salt represented by the formula (B1) to be described later.

A ^- The sulfonyl imide anions represented by, the following may be mentioned.

Examples of the sulfonylmethide anion include the following.

Examples of the carboxylate anion include the following.

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

  When the structural unit (II) is contained in the resin (A), the content of the structural unit (II) is preferably 1 to 20 mol% with respect to the total structural units of the resin (A). Preferably it is 2-15 mol%, More preferably, it is 3-10 mol%.

  The resin (A) may have a structural unit other than the above-described structural unit, and examples of such a structural unit include structural units well known in the art.

The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s).
The structural unit (a1) is preferably a group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group). And at least one selected from the group consisting of at least two.
The structural unit (s) is preferably at least one selected from the group consisting of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by the formula (a2-A). The structural unit (a3) is preferably a group consisting of a structural unit represented by the formula (a3-1), a structural unit represented by the formula (a3-2), and a structural unit represented by the formula (a3-4). Is at least one selected from

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. be able to. The content rate of each structural unit which resin (A) has can be adjusted with the usage-amount of the monomer used for superposition | polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, further preferably 15,000 or less). In the present specification, the weight average molecular weight is a value obtained by gel permeation chromatography under the conditions described in Examples.

<Resin other than resin (A)>
Examples of the resin other than the resin (A) include a resin containing the structural unit (a4) or the structural unit (a5) (hereinafter sometimes referred to as the resin (X)).

Among them, the resin (X) is preferably a resin containing the structural unit (a4).
In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more with respect to the total of all the structural units of the resin (X). More preferably, it is 45 mol% or more.
Examples of the structural unit that the resin (X) may further include a structural unit derived from the structural unit (a1), the structural unit (a2), the structural unit (a3), and other known monomers. Especially, it is preferable that resin (X) is resin which consists only of a structural unit (a4) and / or a structural unit (a5).

Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do. The content rate of each structural unit which resin (X) has can be adjusted with the usage-amount of the monomer used for superposition | polymerization.
The weight average molecular weight of the resin (X) is preferably independently 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 the resin (X) is the same as that for the resin (A).
When the resist composition of the present invention contains a resin (A2), the content is usually 1 to 2500 parts by mass (more preferably 10 to 1000 parts by mass) with respect to 100 parts by mass of the resin (A). is there.
Moreover, when a resist composition contains resin (X), the content becomes like this. Preferably it is 1-60 mass parts with respect to 100 mass parts of resin (A), More preferably, it is 1-50 mass parts. More preferably, it is 1-40 mass parts, Most preferably, it is 1-30 mass parts, Most preferably, it is 1-8 mass parts.

  The content of the resin (A) in the resist composition is preferably 80% by mass to 99% by mass and more preferably 90% by mass to 99% by mass with respect to the solid content of the resist composition. Moreover, when resin other than resin (A) is included, the total content rate of resin other than resin (A) and resin (A) is 80 mass% or more and 99 mass% with respect to solid content of a resist composition. It is preferable that it is below, and 90 to 99 mass% is more preferable. In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described later from the total amount of the resist composition. The solid content of the resist composition and the resin content relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Solvent (E)>
The content of the solvent (E) 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 in the resist composition. % Or less. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  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 Esters such as acetone, methyl isobutyl ketone, ketones such as 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. 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 a basic nitrogen-containing organic compound and a salt that generates an acid having a lower 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.
Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

  Examples of the amine 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, Rudicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyl Didecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, 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- Tyrimidazole, 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, preferably aromatic amines such as diisopropylaniline, more preferably 2,6- Diisopropylaniline is mentioned.

  As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

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

Examples of the weak acid inner salt (D) include the following salts.

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

<Other ingredients>
The resist composition of the present invention may contain components other than the above components (hereinafter sometimes referred to as “other components (F)”) as necessary. The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, and the like can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises a salt (I) and a resin (A), and if necessary, an acid generator (B), a resin other than the resin (A), a solvent (E), a quencher ( It can be prepared by mixing C) and other components (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature from 10-40 degreeC according to the kind etc. of resin etc., the solubility with respect to solvents (E), such as resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is 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) The process of apply | coating the resist composition of this invention on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  The resist composition can be applied onto the substrate by a commonly used apparatus such as a spin coater. Examples of the substrate include an inorganic substrate such as a silicon wafer. Before applying the resist composition, the substrate may be washed, or an antireflection film or the like may be formed on the substrate.

By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or using a decompression device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. Moreover, it is preferable that the pressure at the time of drying under reduced pressure is about 1-1.0 * 10 < ⁵ > Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various lasers such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do. In this specification, the irradiation of these radiations may be collectively referred to as “exposure”. At the time of exposure, exposure is usually performed through a mask corresponding to a required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.

  The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection reaction in the acid labile group. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

  The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example. 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 various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkali developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern.

In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
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 Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent 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 only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a different type from the organic developer.

It is preferable to wash the developed resist pattern with a rinse solution. The rinsing 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, and an alcohol solvent or an ester solvent is preferable.
After the cleaning, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

<Application>
The resist composition of the present invention includes 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, particularly an electron. It is suitable as a resist composition for line (EB) exposure or a resist composition for EUV exposure, and is useful for fine processing of semiconductors.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by 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 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)
The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Model 1100 manufactured by Agilent, MASS: LC / MSD manufactured by Agilent). In the following examples, the value of this molecular ion peak is indicated by “MASS”.

式（Ｉ−１−ａ）で表される塩５部及びクロロホルム２５部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、トリフルオロ酢酸０．０８部を添加し、さらに、５０℃で２時間攪拌した。得られた反応混合物を濃縮し、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−１）で表される塩１．１４部を得た。 Example 1: Synthesis of a salt represented by the formula (I-1)

5 parts of the salt represented by the formula (I-1-a) and 25 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 0.08 part of trifluoroacetic acid was added, and the mixture was further stirred at 50 ° C. for 2 hours. The obtained reaction mixture was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes. Then, the supernatant was removed and concentrated to give a compound of formula (I-1) 1.14 parts of the salt represented by the formula:

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 277.0

式（Ｉ−３−ａ）で表される化合物１０部及びクロロホルム３０部を混合し、２３℃で３０分間攪拌した後、４−メチルモルホリンＮ−オキシド５．３６部、イオン交換水１５部及び四酸化オスミウム０．０３部を加え、２３℃で１８時間撹拌した。得られた反応物に、クロロホルム１１０部及び５％シュウ酸水溶液７０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３５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を４回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−３−ｂ）で表される化合物９．８４部を得た。

式（Ｉ−３−ｃ）で表される化合物３．５０部及びアセトニトリル１７．５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−３−ｄ）で表される化合物３．０７部を添加し、さらに、６０℃で１時間攪拌した。得られた反応混合物を２３℃まで冷却した後、式（Ｉ−３−ｂ）で表される化合物５．３４部及びクロロホルム１０．６８部の混合溶液を添加し、さらに、２３℃で２時間攪拌した。得られた反応物に、クロロホルム８０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４回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−３−ｅ）で表される化合物７．５９部を得た。

式（Ｉ−３−ｅ）で表される化合物７．５９部及びアセトニトリル４０部を添加し、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０．３０部及びイオン交換水４．５６部の混合溶液を３０分かけて添加した後、５℃で１８時間攪拌した後、濃縮した。得られた濃縮残渣に、酢酸エチル１２０部及びイオン交換水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。回得られた有機層にイオン交換水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。この水洗操作を５回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−３−ｆ）で表される化合物６．５０部を得た。

式（Ｉ−３−ｇ）で表される塩６．００部及びクロロホルム３０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−３−ｈ）で表される化合物２．３３部を添加し、さらに、６０℃で１時間攪拌した。得られた反応混合物を２３℃まで冷却した後、式（Ｉ−３−ｆ）で表される化合物６．５０部及びクロロホルム１３部の混合溶液を添加し、さらに、２３℃で２時間攪拌した。得られた反応物に、クロロホルム１２０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、５％シュウ酸水溶液１８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５回繰り返した。得られた有機層を濃縮した後、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−３−ｊ）で表される塩６．７３部を得た。

式（Ｉ−３−ｊ）で表される塩５部及びクロロホルム２５部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、トリフルオロ酢酸０．０６部を添加し、さらに、５０℃で２時間攪拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水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。得られた有機層を濃縮し、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−３）で表される塩３．２８部を得た。 Example 2: Synthesis of a salt represented by the formula (I-3)

After mixing 10 parts of the compound represented by the formula (I-3-a) and 30 parts of chloroform and stirring at 23 ° C. for 30 minutes, 5.36 parts of 4-methylmorpholine N-oxide, 15 parts of ion-exchanged water and 0.03 part of osmium tetroxide was added and stirred at 23 ° C. for 18 hours. To the obtained reaction product, 110 parts of chloroform and 70 parts of 5% oxalic acid aqueous solution were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 35 parts of ion-exchanged water was added to the obtained organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 4 times. The obtained organic layer was concentrated to obtain 9.84 parts of a compound represented by the formula (I-3-b).

3.50 parts of the compound represented by the formula (I-3-c) and 17.5 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 3.07 parts of a compound represented by the formula (I-3-d) was added, and the mixture was further stirred at 60 ° C. for 1 hour. After cooling the obtained reaction mixture to 23 ° C., a mixed solution of 5.34 parts of the compound represented by the formula (I-3-b) and 10.68 parts of chloroform was added, and further at 23 ° C. for 2 hours. Stir. To the obtained reaction product, 80 parts of chloroform and 40 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 40 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 4 times. The obtained organic layer was concentrated to obtain 7.59 parts of a compound represented by the formula (I-3-e).

7.59 parts of a compound represented by the formula (I-3-e) and 40 parts of acetonitrile were added, stirred at 23 ° C. for 30 minutes, and then cooled to 5 ° C. A mixed solution of 0.30 parts of sodium borohydride and 4.56 parts of ion-exchanged water was added to the obtained mixed solution over 30 minutes, and the mixture was stirred at 5 ° C. for 18 hours and then concentrated. To the obtained concentrated residue, 120 parts of ethyl acetate and 50 parts of ion exchange water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. 50 parts of ion-exchanged water was added to the organic layer obtained and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. The obtained organic layer was concentrated to obtain 6.50 parts of a compound represented by the formula (I-3-f).

6.00 parts of the salt represented by the formula (I-3-g) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 2.33 parts of a compound represented by the formula (I-3-h) was added, and the mixture was further stirred at 60 ° C. for 1 hour. After cooling the obtained reaction mixture to 23 ° C., a mixed solution of 6.50 parts of the compound represented by the formula (I-3-f) and 13 parts of chloroform was added, and the mixture was further stirred at 23 ° C. for 2 hours. . To the obtained reaction product, 120 parts of chloroform and 40 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. 18 parts of 5% oxalic acid aqueous solution was added to the obtained organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes, and then the supernatant was removed and concentrated to give a compound of formula (I-3 6.73 parts of the salt represented by -j) were obtained.

5 parts of the salt represented by the formula (I-3-j) and 25 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 0.06 part of trifluoroacetic acid was added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. After cooling the obtained reaction mixture to 23 ° C., 50 parts of chloroform and 50 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation and taking out the organic layer. To the obtained organic layer, 50 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes. Then, the supernatant was removed and concentrated to obtain the formula (I-3). 3.28 parts of the salt represented by

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 455.1

式（Ｉ−４−ａ）で表される化合物９．４７部及びクロロホルム３０部を混合し、２３℃で３０分間攪拌した後、４−メチルモルホリンＮ−オキシド５．３６部、イオン交換水１５部及び四酸化オスミウム０．０３部を加え、２３℃で１８時間撹拌した。得られた反応物に、クロロホルム１１０部及び５％シュウ酸水溶液７０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３５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を４回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−４−ｂ）で表される化合物９．１２部を得た。

式（Ｉ−４−ｃ）で表される化合物３．５０部及びアセトニトリル１７．５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−４−ｄ）で表される化合物３．０７部を添加し、さらに、６０℃で１時間攪拌した。得られた反応混合物を２３℃まで冷却した後、式（Ｉ−４−ｂ）で表される化合物５．０９部及びクロロホルム１０．１８部の混合溶液を添加し、さらに、２３℃で２時間攪拌した。得られた反応物に、クロロホルム８０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４回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−４−ｅ）で表される化合物７．４２部を得た。

式（Ｉ−４−ｅ）で表される化合物７．３６部及びアセトニトリル４０部を添加し、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０．３０部及びイオン交換水４．５６部の混合溶液を３０分かけて添加した後、５℃で１８時間攪拌した後、濃縮した。得られた濃縮残渣に、酢酸エチル１２０部及びイオン交換水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。この水洗操作を５回繰り返した。得られた有機層を濃縮することにより、式（Ｉ−４−ｆ）で表される化合物６．３２部を得た。

式（Ｉ−４−ｇ）で表される塩６．００部及びクロロホルム３０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−４−ｈ）で表される化合物２．３３部を添加し、さらに、６０℃で１時間攪拌した。得られた反応混合物を２３℃まで冷却した後、式（Ｉ−４−ｆ）で表される化合物６．３１部及びクロロホルム１３部の混合溶液を添加し、さらに、２３℃で２時間攪拌した。得られた反応物に、クロロホルム１２０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、５％シュウ酸水溶液１８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５回繰り返した。得られた有機層を濃縮した後、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−４−ｊ）で表される塩６．０９部を得た。

式（Ｉ−４−ｊ）で表される塩４．９２部及びクロロホルム２５部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、トリフルオロ酢酸０．０６部を添加し、さらに、５０℃で２時間攪拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水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。得られた有機層を濃縮し、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−４）で表される塩２．９９部を得た。 Example 3: Synthesis of a salt represented by the formula (I-4)

After 9.47 parts of the compound represented by the formula (I-4-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes, 5.36 parts of 4-methylmorpholine N-oxide, 15 ion-exchanged water And 0.03 part of osmium tetroxide were added and stirred at 23 ° C. for 18 hours. To the obtained reaction product, 110 parts of chloroform and 70 parts of 5% oxalic acid aqueous solution were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 35 parts of ion-exchanged water was added to the obtained organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 4 times. The obtained organic layer was concentrated to obtain 9.12 parts of a compound represented by the formula (I-4-b).

3.50 parts of the compound represented by the formula (I-4-c) and 17.5 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 3.07 parts of a compound represented by the formula (I-4-d) was added, and the mixture was further stirred at 60 ° C. for 1 hour. After cooling the obtained reaction mixture to 23 ° C., a mixed solution of 5.09 parts of the compound represented by the formula (I-4-b) and 10.18 parts of chloroform was added, and further at 23 ° C. for 2 hours. Stir. To the obtained reaction product, 80 parts of chloroform and 40 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 40 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 4 times. The obtained organic layer was concentrated to obtain 7.42 parts of a compound represented by the formula (I-4-e).

7.36 parts of a compound represented by the formula (I-4-e) and 40 parts of acetonitrile were added, stirred at 23 ° C. for 30 minutes, and then cooled to 5 ° C. A mixed solution of 0.30 parts of sodium borohydride and 4.56 parts of ion-exchanged water was added to the obtained mixed solution over 30 minutes, and the mixture was stirred at 5 ° C. for 18 hours and then concentrated. To the obtained concentrated residue, 120 parts of ethyl acetate and 50 parts of ion exchange water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 50 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. The obtained organic layer was concentrated to obtain 6.32 parts of a compound represented by the formula (I-4-f).

6.00 parts of the salt represented by the formula (I-4-g) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 2.33 parts of a compound represented by the formula (I-4-h) was added, and the mixture was further stirred at 60 ° C. for 1 hour. The obtained reaction mixture was cooled to 23 ° C., a mixed solution of 6.31 parts of the compound represented by the formula (I-4-f) and 13 parts of chloroform was added, and the mixture was further stirred at 23 ° C. for 2 hours. . To the obtained reaction product, 120 parts of chloroform and 40 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. 18 parts of 5% oxalic acid aqueous solution was added to the obtained organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes, and then the supernatant was removed and concentrated to give a compound of formula (I-4 6.09 parts of the salt represented by -j) were obtained.

4.92 parts of the salt represented by the formula (I-4-j) and 25 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 0.06 part of trifluoroacetic acid was added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. After cooling the obtained reaction mixture to 23 ° C., 50 parts of chloroform and 50 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation and taking out the organic layer. To the obtained organic layer, 50 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes. Then, the supernatant was removed and concentrated to obtain the formula (I-4). 2.99 parts of the salt represented by

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ^- 441.1

式（Ｉ−７−ｇ）で表される塩８．２５部及びクロロホルム３０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−３−ｈ）で表される化合物２．３３部を添加し、さらに、６０℃で１時間攪拌した。得られた反応混合物を２３℃まで冷却した後、式（Ｉ−３−ｆ）で表される化合物６．５０部及びクロロホルム１３部の混合溶液を添加し、さらに、２３℃で２時間攪拌した。得られた反応物に、クロロホルム１２０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、５％シュウ酸水溶液１８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５回繰り返した。得られた有機層を濃縮した後、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−７−ｊ）で表される塩８．４９部を得た。

式（Ｉ−７−ｊ）で表される塩５部及びクロロホルム２５部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、トリフルオロ酢酸０．０６部を添加し、さらに、５０℃で２時間攪拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水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。得られた有機層を濃縮し、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−７）で表される塩３．１３部を得た。 Example 4: Synthesis of salt represented by formula (I-7)

8.25 parts of the salt represented by the formula (I-7-g) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 2.33 parts of a compound represented by the formula (I-3-h) was added, and the mixture was further stirred at 60 ° C. for 1 hour. After cooling the obtained reaction mixture to 23 ° C., a mixed solution of 6.50 parts of the compound represented by the formula (I-3-f) and 13 parts of chloroform was added, and the mixture was further stirred at 23 ° C. for 2 hours. . To the obtained reaction product, 120 parts of chloroform and 40 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. 18 parts of 5% oxalic acid aqueous solution was added to the obtained organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes, and then the supernatant was removed and concentrated to give a compound of formula (I-7 8.49 parts of the salt represented by -j) were obtained.

5 parts of the salt represented by the formula (I-7-j) and 25 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 0.06 part of trifluoroacetic acid was added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. After cooling the obtained reaction mixture to 23 ° C., 50 parts of chloroform and 50 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation and taking out the organic layer. To the obtained organic layer, 50 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes. Then, the supernatant was removed and concentrated to obtain the formula (I-7). 3.13 parts of the salt represented by

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ^- 485.1

式（Ｉ−１０５−ｇ）で表される塩８．５０部及びクロロホルム３０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−３−ｈ）で表される化合物２．３３部を添加し、さらに、６０℃で１時間攪拌した。得られた反応混合物を２３℃まで冷却した後、式（Ｉ−３−ｆ）で表される化合物６．５０部及びクロロホルム１３部の混合溶液を添加し、さらに、２３℃で２時間攪拌した。得られた反応物に、クロロホルム１２０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、５％シュウ酸水溶液１８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５回繰り返した。得られた有機層を濃縮した後、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−１０５−ｊ）で表される塩８．２１部を得た。

式（Ｉ−１０５−ｊ）で表される塩５部及びクロロホルム２５部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、トリフルオロ酢酸０．０６部を添加し、さらに、５０℃で２時間攪拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水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。得られた有機層を濃縮し、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−１０５）で表される塩２．９６部を得た。 Example 5: Synthesis of salt represented by formula (I-105)

8.50 parts of the salt represented by the formula (I-105-g) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 2.33 parts of a compound represented by the formula (I-3-h) was added, and the mixture was further stirred at 60 ° C. for 1 hour. After cooling the obtained reaction mixture to 23 ° C., a mixed solution of 6.50 parts of the compound represented by the formula (I-3-f) and 13 parts of chloroform was added, and the mixture was further stirred at 23 ° C. for 2 hours. . To the obtained reaction product, 120 parts of chloroform and 40 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. 18 parts of 5% oxalic acid aqueous solution was added to the obtained organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentration of the obtained organic layer, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes. 8.21 parts of the salt represented by -j) were obtained.

5 parts of the salt represented by the formula (I-105-j) and 25 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 0.06 part of trifluoroacetic acid was added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. After cooling the obtained reaction mixture to 23 ° C., 50 parts of chloroform and 50 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation and taking out the organic layer. To the obtained organic layer, 50 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes, and then the supernatant was removed and concentrated to give the formula (I-105). 2.96 parts of a salt represented by the formula:

MASS (ESI (+) Spectrum): M ⁺ 281.1
MASS (ESI (−) Spectrum): M ^- 485.1

式（Ｉ−１１９−ｇ）で表される塩９．００部及びクロロホルム３０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−３−ｈ）で表される化合物２．３３部を添加し、さらに、６０℃で１時間攪拌した。得られた反応混合物を２３℃まで冷却した後、式（Ｉ−３−ｆ）で表される化合物６．５０部及びクロロホルム１３部の混合溶液を添加し、さらに、２３℃で２時間攪拌した。得られた反応物に、クロロホルム１２０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、５％シュウ酸水溶液１８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５回繰り返した。得られた有機層を濃縮した後、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−１１９−ｊ）で表される塩８．０１部を得た。

式（Ｉ−１１９−ｊ）で表される塩５部及びクロロホルム２５部を混合し、２３℃で３０分間攪拌した。得られた混合溶液に、トリフルオロ酢酸０．０６部を添加し、さらに、５０℃で２時間攪拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水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。得られた有機層を濃縮し、濃縮残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて、２３℃で３０分間攪拌した後、上澄み液を除去し、濃縮することにより、式（Ｉ−１１９）で表される塩２．６２部を得た。 Example 6: Synthesis of salt represented by formula (I-119)

9.00 parts of the salt represented by the formula (I-119-g) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 2.33 parts of a compound represented by the formula (I-3-h) was added, and the mixture was further stirred at 60 ° C. for 1 hour. After cooling the obtained reaction mixture to 23 ° C., a mixed solution of 6.50 parts of the compound represented by the formula (I-3-f) and 13 parts of chloroform was added, and the mixture was further stirred at 23 ° C. for 2 hours. . To the obtained reaction product, 120 parts of chloroform and 40 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. 18 parts of 5% oxalic acid aqueous solution was added to the obtained organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 60 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes, and then the supernatant was removed and concentrated to give the formula (I-119 8.01 parts of the salt represented by -j) were obtained.

5 parts of the salt represented by the formula (I-119-j) and 25 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 0.06 part of trifluoroacetic acid was added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. After cooling the obtained reaction mixture to 23 ° C., 50 parts of chloroform and 50 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation and taking out the organic layer. To the obtained organic layer, 50 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes, and then the supernatant was removed and concentrated to obtain the formula (I-119). 2.62 parts of a salt represented by the formula:

MASS (ESI (+) Spectrum): M ⁺ 317.1
MASS (ESI (−) Spectrum): M ^- 485.1

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

  Hereinafter, these monomers are referred to as “monomer (a1-1-3)” or the like according to the formula number.

Synthesis Example 1 [Synthesis of Resin A1]
As the monomer, a monomer (a1-4-2), a monomer (a1-1-3), a monomer (a1-2-6) and a monomer (II-2-A-1-1) are used, and the molar ratio [monomer (A1-4-2): monomer (a1-1-3): monomer (a1-2-6): monomer (II-2-A-1-1)] is a ratio of 35: 24: 38: 3 Furthermore, 1.5 mass times of methyl isobutyl ketone was mixed with this monomer mixture with respect to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and this was heated at 83 ° C. for about 5 hours for polymerization. Went. Thereafter, a p-toluenesulfonic acid aqueous solution was added to the polymerization reaction solution, and the mixture was stirred for 6 hours, followed by liquid separation. The obtained organic layer is poured into a large amount of n-heptane to precipitate a resin, which is filtered and collected to obtain a resin A1 (copolymer) having a weight average molecular weight of about 4.8 × 10 ³ in a yield of 78. %. This resin A1 has the following structural units.

Synthesis Example 2 [Synthesis of Resin A2]
As the monomer, monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) were used, and the molar ratio [monomer (a1-4-2): monomer (a1-1) -3): monomer (a1-2-6)] is mixed at a ratio of 38:24:38, and this monomer mixture is further added 1.5 times by mass with respect to the total mass of all monomers. Of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile as an initiator was added so as to be 7 mol% with respect to the total number of moles of all monomers, and this was heated at 85 ° C. for about 5 hours to polymerize. Went. Thereafter, a p-toluenesulfonic acid aqueous solution was added to the polymerization reaction solution, and the mixture was stirred for 6 hours, followed by liquid separation. The obtained organic layer is poured into a large amount of n-heptane to precipitate a resin, which is filtered and collected to obtain a resin A2 (copolymer) having a weight average molecular weight of about 4.6 × 10 ³ in a yield of 74. %. This resin A2 has the following structural units.

<Preparation of resist composition>
As shown in Table 5, the following components were mixed, and the resulting mixture was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

ＩＸ−２：式（ＩＸ−２）で表される塩（特開２０１３−５４３４４号公報の実施例に従って合成）

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

Ｄ１：（東京化成工業（株）製）

＜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, A2: Resin A1, Resin A2
<Compound (I)>
I-1: Salt represented by formula (I-1) I-3: Salt represented by formula (I-3) I-4: Salt represented by formula (I-4) I-7: Formula Salt represented by (I-7) I-105: Salt represented by formula (I-105) I-119: Salt represented by formula (I-119) IX-1: Formula (IX-1) (Synthesized according to the examples of JP2012-224615A)

IX-2: a salt represented by the formula (IX-2) (synthesized according to Examples in JP2013-54344A)

<Quencher (C)>
C1: synthesized by the method described in JP2011-39502A

D1: (Tokyo Chemical Industry Co., Ltd.)

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

(Electron beam exposure evaluation of resist composition)
A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 ° C. for 60 seconds. This silicon wafer was spin-coated with a resist composition so that the film thickness of the composition layer was 0.04 μm. Thereafter, the composition layer was formed by pre-baking on a direct hot plate at a temperature shown in the “PB” column of Table 5 for 60 seconds. A line-and-space pattern was directly drawn on the composition layer formed on the wafer using an electron beam drawing machine ("HL-800D 50 keV" manufactured by Hitachi, Ltd.) while changing the exposure stepwise. .
After exposure, post exposure baking is performed for 60 seconds on the hot plate at the temperature shown in the “PEB” column of Table 5, and then paddle development is performed for 60 seconds with an aqueous 2.38 mass% tetramethylammonium hydroxide solution. A resist pattern was obtained.
The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure amount at which the line width and space width of the 60 nm line and space pattern were 1: 1 was defined as effective sensitivity.

  Line edge roughness evaluation (LER): The width of unevenness on the side wall surface of a resist pattern manufactured with effective sensitivity was measured with a scanning electron microscope to determine line edge roughness. The results are shown in Table 6.

  From the above results, it can be seen that according to the resist composition containing the salt of the present invention, the line edge roughness (LER) is good.

  The resist composition containing the salt of the present invention has good line edge roughness and is useful for fine processing of semiconductors.

Claims (7)

A salt represented by the formula (I).

[In the formula (I),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represents 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, the plurality of R ¹ and R ² may be the same as or different from each other.
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 C1-C36 divalent hydrocarbon group which may have a single bond or a substituent, and —CH ₂ — contained in the hydrocarbon group is —O—, —S. -, -CO- or -S (O) _2- may be substituted.
R ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Z ⁺ represents an organic cation. ] The X ¹ is * -CO-O- (wherein * represents a bonding position with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² )). Salt. L ¹ is a divalent hydrocarbon group formed from an alkanediyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms and an alkanediyl group having 1 to 6 carbon atoms (this carbon 3. The salt according to claim 1, wherein —CH ₂ — contained in the hydrogen group may be replaced with —O— or —CO—.   The acid generator containing the salt in any one of Claims 1-3.   A resist composition comprising the acid generator according to claim 4 and a resin having an acid labile group.   6. The resist composition according to claim 5, further comprising a salt that generates an acid having a lower acidity than an acid generated from the acid generator. (1) The process of apply | coating the resist composition of Claim 5 or 6 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.