JP2021147389A - Salt, acid generator, resist composition, and method for producing resist pattern - Google Patents

Abstract

To provide a salt capable of producing a resist pattern having good CD uniformity (CDU) and a resist composition containing the same.SOLUTION: A salt represented by formula (I), an acid generator, and a resist composition containing the same are provided. [In the formula, R1 represents -O-L1-CO-O-R5; L1 represents an alkanediyl group; R5 represents an acid-labile group; Q1 and Q2 each represent F or a perfluoroalkyl group; R11 and R12 each represent H, F or the like; z represents an integer of 0-6; X1 represents *-CO-O-, *-O-CO- or the like; A1 represents a group formed by combining a saturated cyclic hydrocarbon group and an alkanediyl group; and R13 represents an optionally substituted cyclic hydrocarbon group.]SELECTED DRAWING: None

Description

The present invention relates to a method for producing a salt, an acid generator, a resist composition and a resist pattern.

特許文献２には、下記式で表される塩を酸発生剤として含有するレジスト組成物が記載されている。

特許文献３には、下記式で表される塩を酸発生剤として含有するレジスト組成物が記載されている。

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

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

Patent Document 3 describes a resist composition containing a salt represented by the following formula as an acid generator.

Japanese Unexamined Patent Publication No. 2011-126869 Japanese Unexamined Patent Publication No. 2011-006400 Japanese Unexamined Patent Publication No. 2012-003249

An object of the present invention is to provide a resist composition that forms a resist pattern having better CD uniformity (CDU) than a resist pattern formed from the resist composition containing the above salt.

［式（Ｉ）中、
Ｒ^１は、−Ｏ−Ｌ^１−ＣＯ−Ｏ−Ｒ^５を表す。
Ｌ^１は、炭素数１〜６のアルカンジイル基を表す。
Ｒ^５は、酸不安定基を表す。
Ｒ^２、Ｒ^３及びＲ^４は、それぞれ独立に、ハロゲン原子、炭素数１〜４のフッ素化アルキル基又は炭素数１〜１８の炭化水素基を表し、該炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
ｍ２は、０〜４のいずれかの整数を表し、ｍ２が２以上のとき、複数のＲ^２は互いに同一であっても異なってもよい。
ｍ３は、０〜５のいずれかの整数を表し、ｍ３が２以上のとき、複数のＲ^３は互いに同一であっても異なってもよい。
ｍ４は、０〜５のいずれかの整数を表し、ｍ４が２以上のとき、複数のＲ^４は互いに同一であっても異なってもよい。
Ｑ¹及びＱ²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^１１及びＲ^１２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^1１及びＲ^１2は互いに同一であっても異なってもよい。
Ｘ¹は、＊−ＣＯ−Ｏ−、＊−Ｏ−ＣＯ−、＊−Ｏ−ＣＯ−Ｏ−又は＊−Ｏ−（但し、＊は、Ｃ（Ｒ^１1）（Ｒ^１2）又はＣ（Ｑ¹）（Ｑ²）との結合位を表す。）を表す。
Ａ^１は、飽和環状炭化水素基とアルカンジイル基とを組み合わせてなる基を表し、該飽和環状炭化水素基と該アルカンジイル基との合計炭素数は４〜３６である。前記飽和環状炭化水素基及び前記アルカンジイル基はいずれも置換基を有していてもよく、前記飽和環状炭化水素基及び前記アルカンジイル基に含まれる−ＣＨ₂−は、−Ｏ−、−Ｓ−、−ＣＯ−又は−ＳＯ_２−に置き換わっていてもよい。
Ｒ^１３は、置換基を有していてもよい炭素数３〜２４の環状炭化水素基を表し、該環状炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−、−Ｓ−、−ＣＯ−又は−ＳＯ_２−に置き換わっていてもよい。］
［２］Ｒ^５が、式（１ａ）で表される基又は式（２ａ）で表される基である［１］記載の塩。

［式（１ａ）中、Ｒ^aa1、Ｒ^aa2及びＲ^aa3は、それぞれ独立に、置換基を有していてもよい炭素数１〜８のアルキル基、置換基を有していてもよい炭素数２〜８のアルケニル基、置換基を有していてもよい炭素数３〜２０の脂環式炭化水素基もしくは置換基を有していてもよい炭素数６〜１８の芳香族炭化水素基を表すか、又はＲ^aa1及びＲ^aa2は互いに結合してそれらが結合する炭素原子とともに炭素数３〜２０の脂環式炭化水素基を形成する。
＊は結合手を表す。］

［式（２ａ）中、Ｒ^aa1’及びＲ^aa2’は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^aa3’は、炭素数１〜２０の炭化水素基を表すか、又はＲ^aa2’及びＲ^aa3’は互いに結合してそれらが結合する−Ｃ−Ｘ^ａ−とともに炭素数３〜２０の複素環基を形成し、該炭化水素基及び該複素環基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｓ−で置き換わってもよい。
Ｘ^aは、酸素原子又は硫黄原子を表す。
＊は結合手を表す。］
［３］Ａ^１が、＊−Ｌ^２−ＣＯ−Ｏ−（Ｌ^２は、炭素数３〜１８の飽和環状炭化水素基又は炭素数３〜１８の環状炭化水素基と炭素数１〜４のアルカンジイル基とを組み合わせた基を表し、該飽和環状炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−、−Ｓ−、−ＣＯ−又は−ＳＯ_２−に置き換わっていてもよく、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。＊は、Ｘ^１との結合手を表す。）又は＊−Ｌ^２１−Ｗ^１−Ｌ^２２−ＣＯ−Ｏ−Ｌ^２３−（Ｗ^１は、２価の飽和環状炭化水素基を表し、該飽和環状炭化水素基は置換基を有していてもよく、該飽和環状炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−、−Ｓ−、−ＣＯ−又は−ＳＯ_２−に置き換わっていてもよい。Ｌ^２１、Ｌ^２２及びＬ^２３は、それぞれ独立に、単結合又は炭素数１〜４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。＊は、Ｘ^１との結合部位を表す。）である［１］又は［２］記載の塩。
［４］Ｌ^２及びＷ^１が、下記式（Ｌ^２−１）、式（Ｌ^２−２）、式（Ｌ^２−３）又は式（Ｌ^２−４）で表される基（＊は、結合手を表す。）である［３］記載の塩。

［５］Ｘ^１が、＊−ＣＯ−Ｏ−である［１］〜［４］のいずれかに記載の塩。
［６］ｍ３が１〜２のいずれかの整数であり、
ｍ４が０〜２のいずれかの整数であり、
Ｒ^３及びＲ^４のうちいずれか一方は、フッ素原子、ヨウ素原子又はトリフルオロメチルである［１］〜［５］のいずれかに記載の塩。
［７］ｍ３が１〜２のいずれかの整数であり、
ｍ４が０〜２のいずれかの整数であり、
Ｒ^３及びＲ^４のうちいずれか一方は、−Ｏ−Ｌ^１−ＣＯ−Ｏ−Ｒ^５であり、
複数のＲ^５は、互いに同一であっても異なっていてもよい［１］〜［５］のいずれかに記載の塩。
［８］ｍ２が１または２であり、
複数のＲ^２のうち少なくとも１つは、−Ｏ−Ｌ^１−ＣＯ−Ｏ−Ｒ^５であり、
複数のＲ^５は、互いに同一であっても異なっていてもよい［１］〜［７］のいずれかに記載の塩。
［９］［１］〜［８］のいずれかに記載の塩を含有する酸発生剤。
［１０］［９］記載の酸発生剤と酸不安定基を有する樹脂とを含有するレジスト組成物。
［１１］酸不安定基を有する樹脂が、式（ａ１−１）で表される構造単位及び式（ａ１−２）で表される構造単位からなる群より選ばれる少なくとも１種を含む［１０］記載のレジスト組成物。

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^ａ１及びＬ^ａ２は、それぞれ独立に、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ１−ＣＯ−Ｏ−を表し、ｋ１は１〜７のいずれかの整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数２〜８のアルケニル基、炭素数３〜１８の脂環式炭化水素基、炭素数６〜１８の芳香族炭化水素基又はこれらを組合せた基を表す。
ｍ１は、０〜１４のいずれかの整数を表す。
ｎ１は、０〜１０のいずれかの整数を表す。
ｎ１’は、０〜３のいずれかの整数を表す。］
［１２］酸不安定基を有する樹脂が、式（ａ２−Ａ）で表される構造単位を含む［１０］又は［１１］記載のレジスト組成物。

［式（ａ２−Ａ）中、
Ｒ^a50は、水素原子、ハロゲン原子又はハロゲン原子を有していてもよい炭素数１〜６のアルキル基を表す。
Ｒ^a51は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜１２のアルコキシアルキル基、炭素数２〜１２のアルコキシアルコキシ基、炭素数２〜４のアルキルカルボニル基、炭素数２〜４のアルキルカルボニルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
Ａ^a50は、単結合又は^＊−Ｘ^a51−（Ａ^a52−Ｘ^a52）_nｂ−を表し、＊は−Ｒ^a50が結合する炭素原子との結合手を表す。
Ａ^a52は、炭素数１〜６のアルカンジイル基を表す。
Ｘ^a51及びＸ^a52は、それぞれ独立に、−Ｏ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−を表す。
ｎｂは、０又は１を表す。
ｍｂは０〜４のいずれかの整数を表す。ｍｂが２以上のいずれかの整数である場合、複数のＲ^a51は互いに同一であっても異なってもよい。］
［１３］酸発生剤から発生する酸よりも酸性度の弱い酸を発生する塩をさらに含有する［１０］〜［１２］のいずれかに記載のレジスト組成物。
［１４］（１）［１０］〜［１３］のいずれかに記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程、を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A salt represented by the formula (I).

[In formula (I),
R ¹ represents ^{−OL 1} −CO—O—R ^5.
L ¹ represents an alkanediyl group having 1 to 6 carbon atoms.
R ⁵ represents an acid unstable group.
R ² , R ³ and R ⁴ independently represent a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms or a hydrocarbon group having 1 to 18 carbon atoms, and are contained in the hydrocarbon group -CH _2. -May be replaced by -O- or -CO-.
m2 represents any integer from 0 to 4, and when m2 is 2 or more, a plurality of R ^2s may be the same or different from each other.
m3 represents an integer of 0 to 5, when m3 is 2 or more, plural R ³ may be the same or different from each other.
m4 represents an integer of 0 to 5, when m4 is 2 or more, plural R ⁴ may be the same or different from each other.
Q ¹ and Q ² independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹¹ and R ¹² independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹¹ and R ¹² may be the same or different from each other.
X ¹ is * -CO-O-, * -O-CO-, * -O-CO-O- or * -O- (where * is C (R ¹¹ ) (R ¹² ) or C (Q). ¹ ) Represents the binding site with (Q ^2).).
A ¹ represents a group formed by combining a saturated cyclic hydrocarbon group and an alkanediyl group, and the total carbon number of the saturated cyclic hydrocarbon group and the alkanediyl group is 4 to 36. Both the saturated cyclic hydrocarbon group and the alkanediyl group may have a substituent, and −CH ₂ − contained in the saturated cyclic hydrocarbon group and the alkanediyl group is −O−, −S. -, - CO- or -SO ₂ - may be replaced to.
R ¹³ represents a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and −CH ₂ − contained in the cyclic hydrocarbon group is −O−, −S−, −CO. -Or -SO _2- may be replaced. ]
[2] ^{R 5} is a group represented by the group or the formula represented by the formula (1a) (2a) [1 ] salt according.

[In the formula (1a), ^Raa1 , ^Raa2 and ^Raa3 independently have an alkyl group having 1 to 8 carbon atoms which may have a substituent and a carbon number which may have a substituent. An alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have an alkenyl group of 2 to 8 and a substituent or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. Represented or ^Raa1 and ^Raa2 bond with each other to form an alicyclic hydrocarbon group with 3 to 20 carbon atoms with the carbon atoms to which they are attached.
* Represents a bond. ]

Wherein (2a), R ^{aa1 'and} R ^aa2' each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^{aa3 'is} a hydrocarbon group having 1 to 20 carbon atoms represents or R ^{aa2 'and} R ^aa3' is bonded to -C-X a to which they are attached to one another ^- to form together with heterocyclic group having 3 to 20 carbon atoms, the hydrocarbon group and heterocyclic group The included −CH ₂₋ may be replaced by −O− or −S−.
X ^a represents an oxygen atom or a sulfur atom.
* Represents a bond. ]
[3] A ¹ is * -L ^2- CO-O- (L ² is a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms or a cyclic hydrocarbon group having 3 to 18 carbon atoms and having 1 to 4 carbon atoms. represents a group obtained by combining the alkanediyl group, -CH ₂ contained in the saturated cyclic hydrocarbon group - is, -O -, - S -, - CO- or -SO ₂ - may be replaced to, the _{-CH 2} − contained in the alkylandyl group may be replaced with −O − or −CO−. * Represents a bond with ^{X 1 ) or * −L 21} −W ¹ −L ^{22. -CO-O-L 23 - (} W 1 represents a divalent saturated cyclic hydrocarbon group, the saturated cyclic hydrocarbon group may have a substituent group, contained in the saturated cyclic hydrocarbon group -CH _2- may be replaced with -O-, -S-, -CO- or -SO _2-. ^{L 21} , L ²² and L ²³ are independently single-bonded or have 1 to 1 carbon atoms, respectively. represents 4 alkanediyl group, -CH ₂ contained in the alkanediyl group -. is that may be replaced by -O- or -CO- * is a) represents the binding site to ^{X 1.} The salt according to [1] or [2].
[4] ^{L 2} and ^{W 1} is the following formula ^(L 2 -1), formula ^(L 2 -2), the group represented by the formula ^(L 2 -3) or formula ^(L 2 -4) ^(* is , The salt according to [3].

[5] The salt according to any one of [1] to [4], wherein ^{X 1 is * -CO-O-.}
[6] m3 is an integer of 1 to 2, and
m4 is an integer of 0 to 2,
The salt according to any one of [1] to [5], wherein any one of R ³ and R ^{4 is a fluorine atom, an iodine atom or trifluoromethyl.}
[7] m3 is an integer of 1 to 2, and
m4 is an integer of 0 to 2,
One of R ³ and R ⁴ is -OL ^1- CO-O-R ⁵ .
The salt according to any one of [1] to [5], wherein the plurality of R ^{5s may be the same or different from each other.}
[8] m2 is 1 or 2,
At least one of the plurality of ^{R 2 is} -O-L 1 -CO-O- R 5,
The salt according to any one of [1] to [7], wherein the plurality of R ^{5s may be the same or different from each other.}
[9] An acid generator containing the salt according to any one of [1] to [8].
[10] A resist composition containing the acid generator according to [9] and a resin having an acid unstable group.
[11] The resin having an acid unstable group contains at least one selected from the group consisting of the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) [10]. ] The resist composition described.

[In the formula (a1-1) and the formula (a1-2),
^La1 and ^La2 independently represent -O- or * -O- (CH ₂ ) _k1- CO-O-, k1 represents an integer of 1 to 7, and * represents -CO-. Represents a bond with.
R ^a4 and R ^a5 independently represent a hydrogen atom or a methyl group, respectively.
R ^a6 and R ^a7 independently have an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic group having 6 to 18 carbon atoms. Represents a hydrocarbon group or a group combining these groups.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1'represents an integer of 0 to 3. ]
[12] The resist composition according to [10] or [11], wherein the resin having an acid unstable group contains a structural unit represented by the formula (a2-A).

[In formula (a2-A),
R ^a50 represents an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, and a carbon number of carbon atoms. It represents an alkylcarbonyl group of 2 to 4, an alkylcarbonyloxy group of 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a50 represents a single bond or ^* −X ^a51 − (A ^a52 −X ^a52 ) _nb −, and * represents a bond with the carbon atom to which ^{−R a50 is bonded.}
A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 independently represent -O-, -CO-O- or -O-CO-, respectively.
nb represents 0 or 1.
mb represents any integer from 0 to 4. When mb is any integer of 2 or more, the plurality of Ra ^51s may be the same or different from each other. ]
[13] The resist composition according to any one of [10] to [12], which further contains a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[14] (1) A step of applying the resist composition according to any one of [10] to [13] onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
A method for producing a resist pattern, which comprises (4) 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 CD uniformity (CDU).

In the present specification, the "(meth) acrylic monomer" is _{derived from 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 species selected from the group. Similarly, "(meth) acrylate" and "(meth) acrylic acid" are "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, respectively". Means. When a structural unit having "CH ₂ = C (CH ₃ ) -CO-" or "CH ₂ = CH-CO-" is exemplified, a structural unit having both groups is similarly exemplified. It shall be. In addition, any of the groups described in the present specification that can have both a linear structure and a branched structure may be used. The “combined group” means a group obtained by binding two or more of the exemplified groups, and the valence of these groups may be appropriately changed depending on the bonding form. "Derived" or "derived" means that the polymerizable C = C bond contained in the molecule becomes a -CC- group by polymerization. If a steric isomer is present, it includes all steric isomers.

［式中、全ての符号は、それぞれ前記と同じ意味を表す。］ The present invention relates to a salt represented by the formula (I) (hereinafter sometimes referred to as "salt (I)").
Of the salt (I), the side having a negative charge may be referred to as "anion (I)", and the side having a positive charge may be referred to as "cation (I)".

[In the formula, all the symbols have the same meanings as described above. ]

In the formula (I), the alkanediyl group in L ^{1 constituting R 1} includes a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5-. Linear alkanediyl groups such as diyl groups, hexane-1,6-diyl groups; and ethane-1,1-diyl groups, propane-1,1-diyl groups, propane-1,2-diyl groups, 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 Examples thereof include branched alkanediyl groups such as −methylbutane-1,4-diyl group.
L ¹ is preferably an alkanediyl group having 1 to 3 carbon atoms, and more preferably a methylene group.

［式（１ａ）中、Ｒ^aa1、Ｒ^aa2及びＲ^aa3は、それぞれ独立に、置換基を有していてもよい炭素数１〜８のアルキル基、置換基を有していてもよい炭素数２〜８のアルケニル基、置換基を有していてもよい炭素数３〜２０の脂環式炭化水素基もしくは置換基を有していてもよい炭素数６〜１８の芳香族炭化水素基を表すか、又はＲ^aa1及びＲ^aa2は互いに結合してそれらが結合する炭素原子とともに炭素数３〜２０の脂環式炭化水素基を形成する。
＊は結合手を表す。］

［式（２ａ）中、Ｒ^aa1’及びＲ^aa2’は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^aa3’は、炭素数１〜２０の炭化水素基を表すか、又はＲ^aa2’及びＲ^aa3’は互いに結合してそれらが結合する−Ｃ−Ｘ^ａ−とともに炭素数３〜２０の複素環基を形成し、該炭化水素基及び該複素環基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｓ−で置き換わってもよい。
Ｘ^aは、酸素原子又は硫黄原子を表す。
＊は結合手を表す。］ The acid-labile group of R ⁵ constituting R ¹ means a group in which the group represented by ^{R 5} is eliminated when it comes into contact with an acid (for example, trifluoromethanesulfonic acid) to form a carboxy group.
Examples of the acid-labile group include a group represented by the formula (1a) (hereinafter, sometimes referred to as “acid-labile group (1a)”) and a group represented by the formula (2a) (hereinafter, sometimes “acid”). Unstable group (2a) ") is preferable.

[In the formula (1a), ^Raa1 , ^Raa2 and ^Raa3 independently have an alkyl group having 1 to 8 carbon atoms which may have a substituent and a carbon number which may have a substituent. An alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have an alkenyl group of 2 to 8 and a substituent or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. Represented or ^Raa1 and ^Raa2 bond with each other to form an alicyclic hydrocarbon group with 3 to 20 carbon atoms with the carbon atoms to which they are attached.
* Represents a bond. ]

Wherein (2a), R ^{aa1 'and} R ^aa2' each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^{aa3 'is} a hydrocarbon group having 1 to 20 carbon atoms represents or R ^{aa2 'and} R ^aa3' is bonded to -C-X a to which they are attached to one another ^- to form together with heterocyclic group having 3 to 20 carbon atoms, the hydrocarbon group and heterocyclic group The included −CH ₂₋ may be replaced by −O− or −S−.
X ^a represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

Ｒ^aa1、Ｒ^aa2及びＲ^aa3の芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニル基、フェナントリル基等のアリール基が挙げられる。芳香族炭化水素基の炭素数は、好ましくは６〜１４であり、より好ましくは６〜１０である。 ^{Examples of the alkyl group of Raa1} , ^Raa2 and Raa3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group and an n-octyl group. Be done. The alkyl group preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms.
The alkenyl group of R ^aa1, R ^aa2 and R ^aa3, ethenyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, tert- butenyl, pentenyl, hexenyl, heptenyl group, octynyl group, Isookuchiniru group, Nonenyl group is mentioned.
^{The alicyclic hydrocarbon groups of Raa1} , ^Raa2 and ^Raa3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* indicates a bond). R ^aa1, the number of carbon atoms in the alicyclic hydrocarbon group R ^aa2 and R ^aa is preferably 3 to 16, more preferably from 3 to 12.

^{Examples of the aromatic hydrocarbon groups of Raa1} , ^Raa2 and ^Raa3 include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group and a phenanthryl group. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10.

Examples of the substituent of the alkyl group having 1 to 8 carbon atoms which may have a substituent include an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and 6 to 18 carbon atoms. Aromatic hydrocarbon groups of. Examples of the substituent of the alkenyl group having 2 to 8 carbon atoms which may have a substituent include an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and 6 to 18 carbon atoms. Aromatic hydrocarbon groups of. Examples of the substituent of the alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent include an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, and 6 to 18 carbon atoms. Aromatic hydrocarbon groups of. Examples of the substituent of the aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent include an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, and 3 to 20 carbon atoms. An alicyclic hydrocarbon group can be mentioned. More specifically, a group combining an alkyl group and an alicyclic hydrocarbon group (methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, norbornylethyl group). Alkylcycloalkyl group or cycloalkylalkyl group), aralkyl group such as benzyl group, aromatic hydrocarbon group having alkyl group (p-methylphenyl group, p-tert-butylphenyl group, trill group, xsilyl group, etc. Aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl) having acumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc. and alicyclic hydrocarbon group Groups, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl groups, and the like.
naa is preferably 1.

^{Examples of -C (R aa1} ) (R ^aa2 ) (R ^{aa3 ) when Raa1} and ^Raa2 are bonded to each other to form an alicyclic hydrocarbon group include the following groups. The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms, and more preferably 3 to 12 carbon atoms. * Represents a bond with -O-.

The group represented by the formula (1a) is a 1,1,1-trialkyl group (a group in which ^Raa1 , ^Raa2 and ^Raa are alkyl groups in the formula (1a), preferably a tert-butoxycarbonyl group. ), 2-Alkyladamantan-2-yl group (in formula (1a), ^Raa1 , ^Raa2 and the carbon atom to which they are bonded form an adamantyl group, and ^Raa3 is an alkyl group) and 1-( during adamantan-1-yl) -1,1-dialkyl group (formula (1a), R ^aa1 and R ^aa2 is an alkyl group, R ^aa3 the like are group) an adamantyl group.

Ｒ^aa1'及びＲ^aa2'のうち、少なくとも１つは水素原子であることが好ましい。 ^{Examples of the hydrocarbon groups of Raa1'} , ^Raa2' and ^Raa3' include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and groups formed by combining these groups.
Alkyl group and alicyclic hydrocarbon group include the same as the groups listed R ^aa1, R ^aa2 and R ^aa.
Examples of the aromatic hydrocarbon group include an aryl group such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group and a phenanthryl group.
Examples of the combined group include a group combining the above-mentioned alkyl group and an alicyclic hydrocarbon group (for example, an alkylcycloalkyl group or a cycloalkylalkyl group), an aralkyl group such as a benzyl group, and an aromatic hydrocarbon having an alkyl group. Group (p-methylphenyl group, p-tert-butylphenyl group, trill group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), alicyclic Examples thereof include aromatic hydrocarbon groups having a formula hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like.
If R ^{aa2 'and} R ^aa3' together with the carbon atoms and X ^a binding to which they are attached together form a heterocyclic ^{group, -C (R aa1 ') (} R aa2') -X a - (R aa3 ' ) Examples include the following groups. * Represents a bond.

Of R ^aa1'and R ^aa2' , at least one is preferably a hydrogen atom.

Specific examples of the acid unstable group (1a) include the following groups. * Represents a bond.

Ｒ^１のベンゼン環への結合位置は、Ｓ^＋に対して、オルト位、メタ位、パラ位のいずれでもよいが、パラ位であることが好ましい。 Specific examples of the acid unstable group (2a) include the following groups. * Represents a bond.

The bond position of R ^{1 to} the benzene ring may be any of the ortho position, the meta position, and the para position with respect to ^{S +, but the para position is preferable.}

^{The fluorinated alkyl group having 1 to 4} carbon atoms of R ² , R ³ and R 4 represents an alkyl group having 1 to 4 carbon atoms having a fluorine atom, and a perfluoroalkyl group having 1 to 4 carbon atoms (trifluoromethyl). Group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group), and 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl Groups and 3,3,4,5,4-pentafluorobutyl groups and the like can be mentioned.
Examples of the hydrocarbon group having 1 to 18 carbon atoms of R ^2, R ³ and R ⁴ form, chain hydrocarbon group such as an alkyl group, an alicyclic hydrocarbon group, aromatic hydrocarbon group and by combining these The groups to be used are mentioned.
Alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group and octyl group. , Nonyl group, decyl group, undecyl group, dodecyl group and the like.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a cycloheptyl group. Cycloalkyl groups such as cyclooctyl group and cyclodecyl group can be mentioned. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the like.
Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group.

As the group formed by the combination, a group in which an aromatic hydrocarbon group and a chain hydrocarbon group are combined (for example, an aromatic hydrocarbon group-alkandyl group- *, an alkyl group-an aromatic hydrocarbon group- *), A group that combines an alicyclic hydrocarbon group and a chain hydrocarbon group (for example, an alicyclic hydrocarbon group-alkandyl group- *, an alkyl group-an alicyclic hydrocarbon group- *), aroma A group that combines a group hydrocarbon group and an alicyclic hydrocarbon group (for example, an aromatic hydrocarbon group-an alicyclic hydrocarbon group- *, an alicyclic hydrocarbon group-an aromatic hydrocarbon group- *) Can be mentioned. * Represents the binding site.
Examples of the aromatic hydrocarbon group-alkandyl group-* include an aralkyl group such as a benzyl group and a phenethyl group.
Examples of the alkyl group-aromatic hydrocarbon group- * include a tolyl group, a xsilyl group, a cumenyl group and the like.
As the alicyclic hydrocarbon group-alkanediyl group-*, cyclohexylmethyl group, cyclohexylethyl group, 1- (adamantan-1-yl) methyl group, 1- (adamantan-1-yl) -1-methylethyl, etc. Cycloalkylalkyl group and the like.
Examples of the alkyl group-alicyclic hydrocarbon group- * include a cycloalkyl group having an alkyl group such as a methylcyclohexyl group, a dimethylcyclohexyl group, and a 2-alkyladamantan-2-yl group.
Examples of the aromatic hydrocarbon group-alicyclic hydrocarbon group-* include a phenylcyclohexyl group and the like.
Examples of the alicyclic hydrocarbon group-aromatic hydrocarbon group-* include a cyclohexylphenyl group.
In the combination, two or more alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined. Moreover, any group may be bonded to the benzene ring.
_{The group in which −CH 2} − contained in the hydrocarbon group is replaced with −O− or −CO− is an alkoxy group having 1 to 11 carbon atoms such as a hydroxy group; a carboxy group; a methoxy group, an ethoxy group, or a butoxy group. Cycloalkoxy group having 3 to 11 carbon atoms such as cyclohexyloxy group; Cycloalkylalkoxy group having 4 to 11 carbon atoms such as cyclohexylmethoxy group; Alkoxycarbonyl group having 2 to 12 carbon atoms such as acetyl group; Alkoxycarbonyl group having 2 to 11 carbon atoms; alkylcarbonyloxy group having 2 to 11 carbon atoms such as acetyloxy group; alkoxycarbonyloxy group having 2 to 11 carbon atoms such as butoxycarbonyloxy group; carbon such as benzoyloxy group Examples thereof include aromatic hydrocarbon groups-carbonyloxy groups of numbers 7 to 11.

m2 is preferably an integer of 0 to 2, more preferably 0 or 2.
m3 and m4 are each independently preferably an integer of 0 to 2, and more preferably 0 or 1.
R ² is a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms or an alkyl group having 1 to 6 carbon atoms (-CH ₂ − contained in the alkyl group is replaced with -O- or -CO-. It may be (may be), ^{−OL 1} −CO—O—R ⁵ ( ^{the symbols of L 1} and R ⁵ are the same as described above), and an alkyl group having 1 to 4 carbon atoms (in the alkyl group). The included −CH ₂₋ may be replaced by −O− or −CO−) or −OL ¹ −CO—O—R ⁵ ( ^{the codes of L 1} and R ⁵ are the same as above). It is more preferable that the alkyl group has 1 to 4 carbon atoms or −OL ¹ −CO—O—R ⁵ ( ^{the symbols of L 1} and R ⁵ are the same as described above). For m2 is 1 or 2, at least one of the plurality of ^{R 2 is} preferably a -O-L 1 -CO-O- R 5.
R ³ and R ⁴ are independently each of a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms or an alkyl group having 1 to 6 carbon atoms (-CH ₂ − contained in the alkyl group is -O- or -O- or It may be replaced with −CO−), ^{−OL 1} −CO—O—R ⁵ ( ^{the symbols of L 1} and R ⁵ are the same as described above), and the halogen atom and the number of carbon atoms are 1. Fluorinated alkyl groups of ~ 4 or alkyl groups having 1 to 4 carbon atoms (-CH ₂ − contained in the alkyl groups may be replaced by −O− or −CO−), −OL ¹ It is more preferably −CO—O—R ⁵ ( ^{the codes of L 1} and R ⁵ are the same as described above), and further preferably a fluorine atom, an iodine atom or a perfluoroalkyl group having 1 to 4 carbon atoms.
Furthermore, m3 is an integer of 1-2, when m4 is an integer of 0 to 2, either one of ^{R 3} and ^{R 4,} a fluorine atom, an iodine atom, a trifluoromethyl group, or - ^{Even more preferably, it is −OL 1} −CO—O—R ⁵ ( ^{the symbols of L 1} and R ⁵ are the same as described above).
Incidentally, in formula (I), if there are multiple R ^5, a plurality of R ⁵ may be different may be the same as each other.

Examples of the cation of the salt (I) include cations represented by the following formulas (I-c-1) to (I-c-26).

Among them, the formulas (I-c-1) to (I-c-9), the formula (I-c-16), the formula (I-c-19), the formula (I-c-20), and the formula ( The cation represented by Ic-25) is preferable, and the formulas (Ic-1) to (Ic-6), the formula (Ic-16), the formula (Ic-19), The cations represented by the formulas (I-c-20) and (I-c-25) are more preferable, and the formulas (I-c-1) to (I-c-4) and (I-c-) are more preferable. 16), the cations represented by the formulas (I-c-19), the formula (I-c-20), and the formula (I-c-25) are more preferable, and the formulas (I-c-1) and the formula (I). -C-3), formula (I-c-4), formula (I-c-16), formula (I-c-19), formula (I-c-20), formula (I-c-25) The cation represented by is even more preferable.

In the formula ^(I), perfluoroalkyl group Q ^1, Q 2, ^{R 11} and ^{R 12,} a trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, a perfluoro sec- butyl group , Perfluorotert-butyl group, perfluoropentyl group, perfluorohexyl group and the like.
Q ¹ and Q ² are independently, preferably a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom.
R ¹¹ and R ¹² are independent, preferably hydrogen or fluorine atoms, respectively.
z is preferably 0 or 1.
X ¹ is preferably * -CO-O- or * -O-CO-O-, more preferably * -CO-O- (* is C (R ¹¹ ) (R ¹² ) or. It represents a bond with C (Q ¹ ) (Q ^2).)

A ¹ represents a group formed by combining a saturated cyclic hydrocarbon group and an alkanediyl group.
The saturated cyclic hydrocarbon group may be monocyclic, polycyclic or spiro ring. For example, the following groups can be mentioned. The bond can be in any position.

The ^{saturated cyclic hydrocarbon group contained in A 1} preferably has 3 to 35 carbon atoms, more preferably 3 to 34 carbon atoms, and further preferably 3 to 18 carbon atoms. Those having 3 to 16 carbon atoms are even more preferable.
The number of saturated cyclic hydrocarbon groups contained in ^{A 1 may be one or more.} Examples of the saturated cyclic hydrocarbon group, such as cyclopentyl group, cyclohexyl group, cycloheptyl group, monocyclic saturated cyclic hydrocarbon groups such as cyclooctyl group, and a norbornyl group, following formula (A 1 ^-1) More preferably, a polycyclic saturated cyclic hydrocarbon group such as a group represented by, a group represented by the formula (A ^1-2 ), a group represented by the formula (A ^{1-3), or the like is preferable.} group, more preferably a group represented by group represented by the following formula ^(a 1 -1), group or the formula represented by the following formula ^{(a 1 -2) (a 1} -3), following still more preferably a group of the formula a group represented by ^(a 1 -1), the following radical, or the formula represented by ^{(a 1 -2) (a 1} -3), the following formula ( It is more preferable that the group is represented by A ^1-2). The bond can be in any position.

なかでも、以下の基が好ましい。

In the saturated cyclic hydrocarbon group, -CH _2- contained in the saturated cyclic hydrocarbon group may be replaced with -O-, -S-, -SO _{2- or -CO-. When -CH 2-} contained in the saturated cyclic hydrocarbon group is replaced with -O-, -S-, -CO- or -SO _2- , the number of carbon atoms before the replacement is the number of carbon atoms of the saturated cyclic hydrocarbon group. And. It is, -O - - -CH ₂ contained a saturated cyclic hydrocarbon group, - S -, - CO- or -SO ₂ - as a group replaced by include the following groups. The bond can be in any position.

Among them, the following groups are preferable.

The alkanediyl group includes 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, and a heptane-. 1,7-Diyl Group, Octane-1,8-Diyl Group, Nonan-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.

Is, -O - - -CH ₂ contained in the alkanediyl group, - S -, - CO- or -SO ₂ - may be replaced with.
_{When -CH 2-} contained in the alkanediyl group is replaced with -O-, -S-, -CO- or -SO _2- , the number of carbon atoms before the replacement is defined as the number of carbon atoms of the alkanediyl group.
As a group in which −CH ₂ − contained in the alkandiyl group is replaced with −O − or −CO−, a carbonyloxy group (−CH ₂ −CH ₂ − contained in the ethylene group is −O−CO−. Alcandiyloxy group (group in which -CH ₂ − contained in the alkandiyl group is replaced with −O−), alcandiyloxycarbonyl group (group contained in the alkandiyl group −CH ₂ − CH ₂ -replaced with -O-CO-), alcandiylcarbonyl group (-CH ₂ − contained in the alcandiyl group replaced with -CO-), alcandiylcarbonyloxy group (alcan) A group in which −CH ₂ −CH ₂₋ contained in the diyl group is replaced with −CO−O−) and the like can be mentioned.
The alkanedioxy group includes a methyleneoxy group, an ethyleneoxy group, a propyleneoxy group, a butyleneoxy group, a pentandiyloxy group, a hexanediyloxy group, an octanediyloxy group, a 2-ethylhexanediyloxy group, and a nonandiyloxy group. , Decandyloxy group, undecandyloxy group and the like.
The alkanediyloxycarbonyl group, the alkanediylcarbonyl group and the alkanediylcarbonyloxy group represent a group in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkanediyl group or alkanediyloxy group.
Examples of the alcandiyloxycarbonyl group include a methyleneoxycarbonyl group, an ethyleneoxycarbonyl group, a butyleneoxycarbonyl group, and the like, and examples of the alcandiylcarbonyl group include an ethylenecarbonyl group, a propylenecarbonyl group, a butylenecarbonyl group, and the like. Examples of the arcandyl carbonyloxy group include an ethylene carbonyloxy group, a propylene carbonyloxy group, and a butylene carbonyloxy group.

The total number of carbon atoms of the saturated cyclic hydrocarbon group and the alkanediyl group is 4 to 36, preferably 4 to 34, more preferably 6 to 32, and even more preferably 8 to 30. Further, both the saturated cyclic hydrocarbon group and the alkanediyl group may have a substituent.

また、Ｗ^１は、２価の飽和環状炭化水素基を表し、該飽和環状炭化水素基は置換基を有していてもよく、該飽和環状炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−、−Ｓ−、−ＣＯ−又は−ＳＯ_２−に置き換わっていてもよい。Ｌ^２１、Ｌ^２２及びＬ^２３は、それぞれ独立に、単結合又は炭素数１〜４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。この場合、Ｗ^１における飽和環状炭化水素基、並びに、Ｌ^２１、Ｌ^２２及びＬ^２３におけるアルカンジイル基としては、上記で例示した基と同様の基が挙げられる。
Ｗ^１は、炭素数６〜１２の多環式の２価の飽和環状炭化水素基（該飽和環状炭化水素基は置換基を有していてもよく、該飽和環状炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−、−Ｓ−、−ＣＯ−又は−ＳＯ_２−に置き換わっていてもよい。）であることが好ましく、炭素数７〜１１の多環式の２価の飽和脂環式炭化水素基（該飽和脂環式炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。）であることがより好ましく、上記式（Ｌ^２−１）で表される基、式（Ｌ^２−２）で表される基、式（Ｌ^２−３）で表される基、又は式（Ｌ^２−４）で表される基であることがさらに好ましく、式（Ｌ^２−２）で表される基が一層好ましい。Ｌ^２１、Ｌ^２２及びＬ^２３は、それぞれ独立に、単結合又は炭素数１〜３のアルカンジイル基（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。）が好ましい。
なかでも、Ａ^１は、＊−Ｌ^２−ＣＯ−Ｏ−又は＊−Ｌ^２１−Ｗ^１−Ｌ^２２−ＣＯ−Ｏ−Ｌ^２３−であるものが好ましく、＊−Ｌ^２−ＣＯ−Ｏ−であるものがより好ましい。 In comprising a combination of a saturated cyclic hydrocarbon group and an alkanediyl group of A ¹ groups, -CH ₂ contained in the alkanediyl group - is, -O -, - S -, - CO- or -SO ₂ - replaced by Is preferable. In this case, one −CH ₂ − may be replaced, but it is preferable that two or more −CH ₂ − are replaced. For example, one _{replaced by one -O-, -S-, -CO- or -SO 2-} , two replaced by -O-, -S- or -CO-, or one or more -O- or -S- and one or more -CO- or -SO ₂ - such as those replaced by the the like. Specific examples thereof include -O-, -CO-, -O-CO-, -CO-O-, and -O-CO-O-. Of these, -O-CO-, -CO-O-, and -O-CO-O- are preferable.
For example, ^{A 1 is, * - L 2 -CO-O} -, * - L 2 -O-CO -, * - L 2 -O-CO-O -, * - L 21 -W 1 -L 22 -CO ^{-O-L 23 -, * -} L 21 -W 1 -L 22 -O-CO-L 23 - or ^{* -L 21 -W 1 -L 22 -O} -CO-O-L 23 - a is what is Can be mentioned. * Represents the binding site with ^{X 1.}
Here, L ² represents a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms or a group combining a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms and an alkanediyl group having 1 to 4 carbon atoms, and the saturation thereof. _{-CH 2-} contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO _{2- , and -CH 2-} contained in the alkanediyl group is-. It may be replaced with O- or -CO-. Examples of the saturated cyclic hydrocarbon group and the alkanediyl group in L ^{2 include the same groups as those exemplified above.}
L ² is a polycyclic divalent saturated cyclic hydrocarbon group having 6 to 12 carbon atoms (the saturated cyclic hydrocarbon group may have a substituent and is contained in the saturated cyclic hydrocarbon group-. CH ₂ - is, -O -, - S -, - CO- or -SO ₂ -. is preferably also may) have been replaced with a divalent saturated cycloaliphatic polycyclic 7 to 11 carbon atoms _{It is more preferably a cyclic hydrocarbon group (-CH 2} − contained in the saturated alicyclic hydrocarbon group may be replaced with −O− or −CO−), and the following formula (L ^{2) is more preferable.} groups represented by -1), the group represented by the formula ^(L 2 -2), the group represented by the formula ^(L 2 -3), or a group represented by the formula ^(L 2 -4) it is further preferable, groups represented by the formula ^(L 2 -2) is more preferred.

Further, W ¹ represents a divalent saturated cyclic hydrocarbon group, the saturated cyclic hydrocarbon group may have a substituent, and −CH ₂ − contained in the saturated cyclic hydrocarbon group is −. It may be replaced with O-, -S-, -CO- or -SO _2-. L ²¹ , L ²² and L ²³ independently represent a single bond or an alkanediyl group having 1 to 4 carbon atoms, and −CH ₂ − contained in the alkanediyl group becomes −O− or −CO−. It may be replaced. In this case, examples of the saturated cyclic hydrocarbon group in ^{W 1} and the ^{alkanediyl group in L 21} , L ^{22 and L 23} include the same groups as those exemplified above.
W ¹ is a polycyclic divalent saturated cyclic hydrocarbon group having 6 to 12 carbon atoms (the saturated cyclic hydrocarbon group may have a substituent and is contained in the saturated cyclic hydrocarbon group-. CH ₂ - is, -O -, - S -, - CO- or -SO ₂ -. is preferably also may) have been replaced with a divalent saturated cycloaliphatic polycyclic 7 to 11 carbon atoms _{It is more preferably a cyclic hydrocarbon group (-CH 2} − contained in the saturated alicyclic hydrocarbon group may be replaced with −O− or −CO−), and the above formula (L ^{2) is more preferable.} groups represented by -1), the group represented by the formula ^(L 2 -2), the group represented by the formula ^(L 2 -3), or a group represented by the formula ^(L 2 -4) it is further preferable, groups represented by the formula ^(L 2 -2) is more preferred. L ²¹ , L ²² and L ²³ are independently single-bonded or have an alkanediyl group having 1 to 3 carbon atoms (-CH ₂ − contained in the alkanediyl group is replaced with −O− or −CO−, respectively. May be preferable.).
Among them, ^{A 1 is,} * - L 2 -CO-O- or ^{* -L 21 -W 1 -L 22 -CO} -O-L 23 - preferably those which ^are, * - L 2 -CO-O- Is more preferable.

The saturated cyclic hydrocarbon group and the alkanediyl group in A ^{1 may have one or more substituents.}
Examples of the saturated cyclic hydrocarbon group and an alkanediyl group substituents which may be possessed by the A ^1, a halogen atom, hydroxy group, a cyano group, a carboxy group, an alkyl group having 1 to 12 carbon atoms, 1 to 12 carbon atoms Alkoxy group, alkoxycarbonyl group having 2 to 13 carbon atoms, alkylcarbonyl group having 2 to 13 carbon atoms, alkylcarbonyloxy group having 2 to 13 carbon atoms, alicyclic hydrocarbon group having 3 to 12 carbon atoms, carbon number of carbon atoms. Examples thereof include 6 to 10 aromatic hydrocarbon groups and groups combining these groups.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group and a dodecyl group. ..
The alkoxy group having 1 to 12 carbon atoms includes a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group and an undecyloxy group. Examples include groups and dodecyloxy groups.
Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group, a pentyloxycarbonyl group, a hexyloxycarbonyl group, an octyloxycarbonyl group, and a 2-ethylhexyloxycarbonyl group. Examples thereof include a nonyloxycarbonyl group, a decyloxycarbonyl group, an undecyloxycarbonyl group and a dodecyloxycarbonyl group.
Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group and a butyryl group.
Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group and a butyryloxy group.
Examples of the alicyclic hydrocarbon group having 3 to 12 carbon atoms include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, adamantyl group and norbornyl group.
Examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms include a phenyl group and a naphthyl group.

The combined groups include a group combining an alkoxy group having 1 to 12 carbon atoms and an alkyl group having 1 to 12 carbon atoms, a group combining a hydroxy group and an alkyl group having 1 to 12 carbon atoms, and a group having 1 to 12 carbon atoms. A group combining 12 alkoxy groups and an alkoxy group having 1 to 12 carbon atoms, a group combining an alkoxy group having 1 to 12 carbon atoms and an alkylcarbonyl group having 2 to 13 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms. Examples thereof include a group in which a group and an alkylcarbonyloxy group having 2 to 13 carbon atoms are combined, a group in which an alkyl group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms are combined, and the like.
Examples of the group in which an alkoxy group having 1 to 12 carbon atoms and an alkyl group having 1 to 12 carbon atoms are combined include an alkoxyalkyl group having 2 to 24 carbon atoms such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, and an ethoxymethyl group. The group etc. can be mentioned.
Examples of the group in which the hydroxy group and the alkyl group having 1 to 12 carbon atoms are combined include a hydroxyalkyl group having 1 to 12 carbon atoms such as a hydroxymethyl group and a hydroxyethyl group.
Examples of the group in which an alkoxy group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms are combined include an alkoxyalkoxy group having 2 to 24 carbon atoms such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, and an ethoxyethoxy group. The group and the like can be mentioned.
Examples of the group in which an alkoxy group having 1 to 12 carbon atoms and an alkylcarbonyl group having 2 to 13 carbon atoms are combined include an alkoxy group having 3 to 25 carbon atoms such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, and an ethoxypropionyl group. Alkoxycarbonyl groups and the like can be mentioned.
Examples of the group in which an alkoxy group having 1 to 12 carbon atoms and an alkylcarbonyloxy group having 2 to 13 carbon atoms are combined include a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, an ethoxypropionyloxy group and the like. Examples thereof include 2 to 24 alkoxyalkylcarbonyloxy groups.
Examples of the group in which an alkyl group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms are combined include an aralkyl group having 7 to 22 carbon atoms such as a benzyl group.

The substituents are a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxyalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an alkylcarbonyloxy group having 2 to 13 carbon atoms. , Preferably an alkoxyalkyl group having 2 to 24 carbon atoms, an alkoxyalkoxy group or a cyano group having 2 to 24 carbon atoms, a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms or 1 carbon group. More preferably, it is a ~ 4 alkoxy group.

Examples of A ¹ include the following groups. * And ** represent a bond, and * represents a bond with ^{X 1.}

具体的には、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロへキシル基、シクロオクチル基、シクロノニル基、シクロデシル基、シクロドデシル基等の単環式シクロアルキル基、ノルボルニル基、アダマンチル基等の多環式シクロアルキル基が挙げられる。
芳香族炭化水素基としては、フェニル基、ビフェニル基、ナフチル基、フェナントリル基等のアリール基が挙げられる。環状炭化水素基の炭素数は、好ましくは３〜１８であり、より好ましくは３〜１６である。
Ｒ^１３の環状炭化水素基に含まれる−ＣＨ_２−が−Ｏ−、−Ｓ−、−ＣＯ−又は−ＳＯ_２−に置き換わっている場合、置き換わる前の炭素数を該環状炭化水素基の総炭素数とする。脂環式炭化水素基に含まれる−ＣＨ_２−が、−Ｏ−、−Ｓ−、−ＣＯ−又は−ＳＯ_２−で置き換わった基としては、以下の基等が挙げられる。結合手は任意の位置とすることができる。

The cyclic hydrocarbon group of R ¹³ may be monocyclic, polycyclic or spirocyclic, and may be saturated or unsaturated, and may be an alicyclic hydrocarbon group, an aromatic hydrocarbon group or a combination thereof. Examples include the group. Examples of the alicyclic hydrocarbon group include the groups shown below. The bond can be in any position.

Specifically, polycyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cyclododecyl group, norbornyl group, adamantyl group and the like. Cyclic cycloalkyl groups can be mentioned.
Examples of the aromatic hydrocarbon group include an aryl group such as a phenyl group, a biphenyl group, a naphthyl group and a phenanthryl group. The cyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 3 to 16 carbon atoms.
Is -O - - -CH ₂ in the cyclic hydrocarbon group ^{R 13, - S -, -} CO- or -SO ₂ - if the is replaced, the total of the cyclic hydrocarbon group carbon numbers before replacing Let it be the number of carbon atoms. It is, -O - - -CH ₂ contained in the alicyclic hydrocarbon group, - S -, - CO- or -SO ₂ - as a substituted radicals, the group, and the like below. The bond can be in any position.

Is -O - - -CH ₂ contained in the alicyclic hydrocarbon group and alicyclic hydrocarbon group for ^{R 13, - S -, -} SO 2 - The or -CO- with replaced groups, the formula (Y1 ) To (Y41), preferably the groups represented by the formulas (Y1) to (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39). It is more preferable that the group is represented by any of the formulas (Y43), and the formula (Y3), the formula (Y4), the formula (Y11), the formula (Y15), the formula (Y18), the formula (Y20), It is more preferable that the group is represented by the formula (Y26), the formula (Y27), the formula (Y30), the formula (Y31), the formula (Y39), the formula (Y40), the formula (Y42) or the formula (Y43). ..

炭素数６〜１０の芳香族炭化水素基としては、フェニル基、ナフチル基等が挙げられる。 The cyclic hydrocarbon group of R ¹³ has a total carbon number of 3 to 24 and may further have one or more substituents. Examples of the substituent include a hydroxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 13 carbon atoms, and an alkyl having 2 to 13 carbon atoms. Examples thereof include a carbonyl group, an alkylcarbonyloxy group having 2 to 13 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a group combining these groups.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and iodine.
Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group and a dodecyl group. ..
The alkoxy group having 1 to 12 carbon atoms includes a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group and an undecyloxy group. Groups, dodecyloxy groups and the like can be mentioned.
The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms are groups in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Represents. Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group, and examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
The alicyclic hydrocarbon group having 3 to 16 carbon atoms may be either a monocyclic or polycyclic group, and examples thereof include the groups shown below. ** represents a bond with an aromatic hydrocarbon group.

Examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms include a phenyl group and a naphthyl group.

As the ^{combined group in the substituent of R 13,} a group combining a hydroxy group and an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms were combined. Examples thereof include a group, a group in which an alkyl group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms are combined.
Examples of the group in which the hydroxy group and the alkyl group having 1 to 12 carbon atoms are combined include a hydroxyalkyl group having 1 to 12 carbon atoms such as a hydroxymethyl group and a hydroxyethyl group.
Examples of the group in which an alkoxy group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms are combined include an alkoxyalkoxy group having 2 to 24 carbon atoms such as an ethoxyethoxy group.
Examples of the group in which an alkyl group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms are combined include an aralkyl group having 7 to 22 carbon atoms such as a benzyl group.

The ^{substituent contained in R 13} is preferably an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxy group or a halogen atom, and an alkyl group having 1 to 4 carbon atoms, a hydroxy group or a hydroxy group. It is more preferably a fluorine atom.

Cyclic hydrocarbon group R ¹³ (cyclic hydrocarbon group, -CH ₂ contained may have a substituent group, the cyclic hydrocarbon group - is, -O -, - S -, - CO- or -SO 2 _- as also may) have replaced include preferably, the alicyclic hydrocarbon group (alicyclic hydrocarbon group which may having 3 to 18 carbon atoms which may have a substituent -CH ₂ - is, -O -, - S -, - CO- or -SO ₂ - may be replaced by), or aromatic having 6 to 18 carbon atoms which may have a substituent carbide It is a hydrogen group, more preferably an alkyl group having 1 to 4 carbon atoms, a hydroxy group, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a hydroxy group or a fluorine atom (the alicyclic hydrocarbon group). _{-CH 2-} contained in is replaced with -O-, -S-, -CO- or -SO _2-). Specifically, preferably, a cyclopentyl group having an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group having an alkyl group having 1 to 4 carbon atoms, an adamantyl group having an alkyl group having 1 to 4 carbon atoms, a hydroxyadamantyl group, and the like. It is an adamantanone group, an adamantanane lactone ring group or a norbornane lactone ring group, and more preferably an adamantyl group having an alkyl group having 1 to 4 carbon atoms, a hydroxyadamantyl group or an adamantanone group.

Examples of the anion (I) include anions represented by the following formulas (Ia-1) to (Ia-20). Among them, the anions represented by the formulas (Ia-1) to (Ia-12), the formula (Ia-18), and the formula (Ia-19) are preferable, and the formulas (Ia-1) and the formula (Ia-2) are preferable. , The anions represented by the formulas (Ia-8) to (Ia-12) and (Ia-19) are more preferable.

Examples of the salt (I) include the salts shown in Table 1. For example, in Table 1, the salt (I-1) is a salt composed of an anion represented by the formula (Ia-1) and a cation represented by the formula (b2-c-1). means.

なかでも、塩（Ｉ）は、塩（Ｉ−１）、塩（Ｉ−２）、塩（Ｉ−８）〜塩（Ｉ−１２）、塩（Ｉ−１９）、塩（Ｉ−２１）、塩（Ｉ−２２）、塩（Ｉ−２８）〜塩（Ｉ−３２）、塩（Ｉ−３９）、塩（Ｉ−４１）、塩（Ｉ−４２）、塩（Ｉ−４８）〜塩（Ｉ−５２）、塩（Ｉ−５９）、塩（Ｉ−６１）、塩（Ｉ−６２）、塩（Ｉ−６８）〜塩（Ｉ−７２）、塩（Ｉ−７９）、塩（Ｉ−８１）、塩（Ｉ−８２）、塩（Ｉ−８８）〜塩（Ｉ−９２）、塩（Ｉ−９９）、塩（Ｉ−１０１）、塩（Ｉ−１０２）、塩（Ｉ−１０８）〜塩（Ｉ−１１２）、塩（Ｉ−１１９）、塩（Ｉ−１２１）、塩（Ｉ−１２２）、塩（Ｉ−１２８）〜塩（Ｉ−１３２）、塩（Ｉ−１３９）、塩（Ｉ−１４１）、塩（Ｉ−１４２）、塩（Ｉ−１４８）〜塩（Ｉ−１５２）、塩（Ｉ−１５９）、塩（Ｉ−１６１）、塩（Ｉ−１６２）、塩（Ｉ−１６８）〜塩（Ｉ−１７２）、塩（Ｉ−１７９）、塩（Ｉ−１８１）、塩（Ｉ−１８２）、塩（Ｉ−１８８）〜塩（Ｉ−１９２）、塩（Ｉ−１９９）、塩（Ｉ−２０１）、塩（Ｉ−２０２）、塩（Ｉ−２０８）〜塩（Ｉ−２１２）、塩（Ｉ−２１９）、塩（Ｉ−２２１）、塩（Ｉ−２２２）、塩（Ｉ−２２８）〜塩（Ｉ−２３２）、塩（Ｉ−２３９）、塩（Ｉ−２４１）、塩（Ｉ−２４２）、塩（Ｉ−２４８）〜塩（Ｉ−２５２）、塩（Ｉ−２５９）、塩（Ｉ−２６１）、塩（Ｉ−２６２）、塩（Ｉ−２６８）〜塩（Ｉ−２７２）、塩（Ｉ−２７９）、塩（Ｉ−２８１）、塩（Ｉ−２８２）、塩（Ｉ−２８８）〜塩（Ｉ−２９２）、塩（Ｉ−２９９）、塩（Ｉ−３０１）、塩（Ｉ−３０２）、塩（Ｉ−３０８）〜塩（Ｉ−３１２）、塩（Ｉ−３１９）、塩（Ｉ−３２１）、塩（Ｉ−３２２）、塩（Ｉ−３２８）〜塩（Ｉ−３３２）、塩（Ｉ−３３９）、塩（Ｉ−３４１）、塩（Ｉ−３４２）、塩（Ｉ−３４８）〜塩（Ｉ−３５２）、塩（Ｉ−３５９）、塩（Ｉ−３６１）、塩（Ｉ−３６２）、塩（Ｉ−３６８）〜塩（Ｉ−３７２）、塩（Ｉ−３７９）、塩（Ｉ−３８１）、塩（Ｉ−３８２）、塩（Ｉ−３８８）〜塩（Ｉ−３９２）、塩（Ｉ−３９９）、塩（Ｉ−４０１）、塩（Ｉ−４０２）、塩（Ｉ−４０８）〜塩（Ｉ−４１２）、塩（Ｉ−４１９）、塩（Ｉ−４２１）、塩（Ｉ−４２２）、塩（Ｉ−４２８）〜塩（Ｉ−４３２）、塩（Ｉ−４３９）、塩（Ｉ−４４１）、塩（Ｉ−４４２）、塩（Ｉ−４４８）〜塩（Ｉ−４５２）、塩（Ｉ−４５９）、塩（Ｉ−４６１）、塩（Ｉ−４６２）、塩（Ｉ−４６８）〜塩（Ｉ−４７２）、塩（Ｉ−４７９）、塩（Ｉ−４８１）、塩（Ｉ−４８２）、塩（Ｉ−４８８）〜塩（Ｉ−４９２）、塩（Ｉ−４９９）、塩（Ｉ−５０１）、塩（Ｉ−５０２）、塩（Ｉ−５０８）〜塩（Ｉ−５１２）、塩（Ｉ−５１９）が好ましい。

Among them, the salt (I) is salt (I-1), salt (I-2), salt (I-8) to salt (I-12), salt (I-19), salt (I-21). , Salt (I-22), Salt (I-28) -Salt (I-32), Salt (I-39), Salt (I-41), Salt (I-42), Salt (I-48)- Salt (I-52), salt (I-59), salt (I-61), salt (I-62), salt (I-68) to salt (I-72), salt (I-79), salt (I-81), salt (I-82), salt (I-88) to salt (I-92), salt (I-99), salt (I-101), salt (I-102), salt ( I-108) to salt (I-112), salt (I-119), salt (I-121), salt (I-122), salt (I-128) to salt (I-132), salt (I) -139), salt (I-141), salt (I-142), salt (I-148) to salt (I-152), salt (I-159), salt (I-161), salt (I- 162), salt (I-168) to salt (I-172), salt (I-179), salt (I-181), salt (I-182), salt (I-188) to salt (I-192) ), Salt (I-199), Salt (I-201), Salt (I-202), Salt (I-208) to Salt (I-212), Salt (I-219), Salt (I-221) , Salt (I-222), Salt (I-228) -Salt (I-232), Salt (I-239), Salt (I-241), Salt (I-242), Salt (I-248)- Salt (I-252), salt (I-259), salt (I-261), salt (I-262), salt (I-268) to salt (I-272), salt (I-279), salt (I-281), salt (I-282), salt (I-288) to salt (I-292), salt (I-299), salt (I-301), salt (I-302), salt ( I-308) to salt (I-321), salt (I-319), salt (I-321), salt (I-322), salt (I-328) to salt (I-332), salt (I) -339), salt (I-341), salt (I-342), salt (I-348) to salt (I-352), salt (I-359), salt (I-361), salt (I- 362), salt (I-368) to salt (I-372), salt (I-379), salt (I-381), salt (I-382), salt (I-388) to salt (I-392) ), Salt (I-399), Salt (I-401), Salt (I-402), Salt (I-408) to Salt (I-421), Salt (I-419), Salt (I-421) , Salt (I-422), Salt (I-428) -Salt (I-432), Salt (I-439), Salt (I-441), Salt (I-442), Salt (I-448)- Salt (I-452), salt (I-459), salt (I-461), salt (I-462), salt (I-468) to salt (I-472), salt (I-479), salt (I-481), salt (I-482), salt (I-488) to salt (I-492), salt (I-499), salt (I-501), salt (I-502), salt ( I-508) to salt (I-512) and salt (I-519) are preferable.

［式中、全ての符号は、それぞれ前記と同じ意味を表す。］
溶剤としては、クロロホルム、モノクロロベンゼン、ジメチルホルムアミド、アセトニトリル、酢酸エチル、水などが挙げられる。
反応温度は、通常１５℃〜８０℃であり、反応時間は、通常０．５〜２４時間である。 <Manufacturing method of salt (I)>
The salt (I) can be produced by reacting a salt represented by the formula (Ia) with a salt represented by the formula (Ib) in a solvent.

[In the formula, all the symbols have the same meanings as described above. ]
Examples of the solvent include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, water and the like.
The reaction temperature is usually 15 ° C. to 80 ° C., and the reaction time is usually 0.5 to 24 hours.

Examples of the salt represented by the formula (Ia) include salts represented by the following formula, which can be easily obtained from the market and can be easily produced by a known manufacturing method. ..

Examples of the salt represented by the formula (Ib) include salts represented by the following, which can be easily obtained from the market, and can also be easily produced by a known production method.

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

As the acid generator (B), either a non-ionic system or an ionic system may be used. Nonionic acid generators include sulfonate esters (eg 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (eg disulfone, etc.). Ketosulfone, sulfonyldiazomethane) and the like. As the ionic acid generator, an onium salt containing an onium cation (for example, a diazonium salt, a phosphonium salt, a sulfonium salt, an iodonium salt) is typical. Examples of the onium salt anion include a sulfonic acid anion, a sulfonylimide anion, and a sulfonylmethide anion.

Examples of the acid generator (B) include Japanese Patent Application Laid-Open No. 63-26653, Japanese Patent Application Laid-Open No. 55-164824, Japanese Patent Application Laid-Open No. 62-69263, Japanese Patent Application Laid-Open No. 63-146038, and Japanese Patent Application Laid-Open No. 63-163452. Kaisho 62-153853, Japanese Patent Application Laid-Open No. 63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. A compound that generates an acid by the radiation described in the above can be used. Moreover, you may use the compound produced by the known method. The acid generator (B) may be used in combination of two or more.

［式（Ｂ１）中、
Ｑ^ｂ１及びＱ^ｂ２は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^ｂ１は、炭素数１〜２４の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３〜２４の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−Ｓ（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, and more preferably a salt represented by the formula (B1) (hereinafter, may be referred to as “acid generator (B1)”, but the salt (I). ) Is excluded.).

[In equation (B1),
Q ^b1 and Q ^b2 independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH _2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. , The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and is contained in the alicyclic hydrocarbon group. CH _2- may be replaced with −O−, −S (O) _{2− or −CO−.}
Z1 ⁺ represents an organic cation. ]

The ^{perfluoroalkyl groups represented by Q b1} and Q ^b2 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and Examples include a perfluorohexyl group.
It is preferable that Q ^b1 and Q ^b2 are independently fluorine atoms or trifluoromethyl groups, and it is more preferable that both are fluorine atoms.

Examples of the divalent saturated hydrocarbon group in L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. 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, Nonan-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. Alcandiyl 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, etc. Valuable alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. The group etc. can be mentioned.

_{Examples of the group in which -CH 2-} contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with -O- or -CO- include formulas (b1-1) to (b1-3). A group represented by any of the above can be mentioned. In the groups represented by the formulas (b1-1) to (b1-3) and the groups represented by the formulas (b1-4) to (b1-11) which are specific examples thereof, * and * * Represents a bond and * 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。
＊及び＊＊は結合手を表し、＊はＹとの結合手を表す。］

[In equation (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 hydrocarbon group may be substituted. _{-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 equation (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 hydrocarbon group may be substituted. _{-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 equation (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 hydrocarbon group may be substituted. _{-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.}
* And ** represent a bond, and * represents a bond with Y. ]

In the groups represented by the formulas (b1-1) to (b1-3), when -CH _2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the carbon before the replacement is performed. Let the number be the number of carbon atoms of the saturated hydrocarbon group.
Examples of the divalent saturated hydrocarbon group include those similar to the 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 with -O- or -CO-.

［式（ｂ１−４）中、
Ｌ^ｂ８は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
式（ｂ１−５）中、
Ｌ^ｂ９は、炭素数１〜２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ｌ^ｂ１０は、単結合又は炭素数１〜１９の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ９及びＬ^ｂ１０の合計炭素数は２０以下である。
式（ｂ１−６）中、
Ｌ^ｂ１１は、炭素数１〜２１の２価の飽和炭化水素基を表す。
Ｌ^ｂ１２は、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１１及びＬ^ｂ１２の合計炭素数は２１以下である。
式（ｂ１−７）中、
Ｌ^ｂ１３は、炭素数１〜１９の２価の飽和炭化水素基を表す。
Ｌ^ｂ１４は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ｌ^ｂ１５は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１３〜Ｌ^ｂ１５の合計炭素数は１９以下である。
式（ｂ１−８）中、
Ｌ^ｂ１６は、炭素数１〜１８の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ｌ^ｂ１７は、炭素数１〜１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１８は、単結合又は炭素数１〜１７の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ１６〜Ｌ^ｂ１８の合計炭素数は１９以下である。
Ｌ^ｂ８は、好ましくは炭素数１〜４の２価の飽和炭化水素基である。
Ｌ^ｂ９は、好ましくは炭素数１〜８の２価の飽和炭化水素基である。
Ｌ^ｂ１０は、好ましくは単結合又は炭素数１〜１９の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１〜８の２価の飽和炭化水素基である。
Ｌ^ｂ１１は、好ましくは炭素数１〜８の２価の飽和炭化水素基である。
Ｌ^ｂ１２は、好ましくは単結合又は炭素数１〜８の２価の飽和炭化水素基である。
Ｌ^ｂ１３は、好ましくは炭素数１〜１２の２価の飽和炭化水素基である。
Ｌ^ｂ１４は、好ましくは単結合又は炭素数１〜６の２価の飽和炭化水素基である。
Ｌ^ｂ１５は、好ましくは単結合又は炭素数１〜１８の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１〜８の２価の飽和炭化水素基である。
Ｌ^ｂ１６は、好ましくは炭素数１〜１２の２価の飽和炭化水素基である。
Ｌ^ｂ１７は、好ましくは炭素数１〜６の２価の飽和炭化水素基である。
Ｌ^ｂ１８は、好ましくは単結合又は炭素数１〜１７の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１〜４の２価の飽和炭化水素基である。
＊及び＊＊は結合手を表し、＊はＹとの結合手を表す。］ The _{group in which -CH 2-} contained in the divalent saturated hydrocarbon group represented by ^{L b1} is replaced with -O- or -CO- is represented by the formula (b1-1) or the formula (b1-3). Is preferred.
Examples of the group represented by the formula (b1-1) include groups represented by the formulas (b1-4) to (b1-8), respectively.

[In equation (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 equation (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and -CH _2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total number of carbon atoms of ^{L b9} and L ^{b10 is 20 or less.}
In equation (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total number of carbon atoms of ^{L b11} and L ^{b12 is 21 or less.}
In equation (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH _2- contained in the divalent saturated hydrocarbon group is replaced with -O- or -CO-. May be good.
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 number of carbon atoms of ^{L b13 to} L ^{b15 is 19 or less.}
In equation (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH _2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total number of carbon atoms of ^{L b16 to} L ^{b18 is 19 or less.}
L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a 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 divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
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.
* And ** represent a bond, and * represents a bond with Y. ]

［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。
＊及び＊＊は結合手を表し、＊はＹとの結合手を表す。］ Examples of the group represented by the formula (b1-3) include the groups represented by the formulas (b1-9) to (b1-11), respectively.

[In equation (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. May be good. _{The −CH 2} − contained in the alkylcarbonyloxy group may be replaced with −O− or −CO−, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total number of carbon atoms of ^{L b19} and L ^{b20 is 23 or less.}
In equation (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. May be good. _{The −CH 2} − contained in the alkylcarbonyloxy group may be replaced with −O− or −CO−, and the 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 equation (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. May be good. _{The −CH 2} − contained in the alkylcarbonyloxy group may be replaced with −O− or −CO−, and the 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.
* And ** represent a bond, and * represents a bond with Y. ]

In addition, in the group represented by the formula (b1-11) from the group represented by the formula (b1-9), when the hydrogen atom contained in the saturated hydrocarbon group is replaced with the alkylcarbonyloxy group, it is replaced. Let the previous carbon number be 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, an adamantylcarbonyloxy group and the like.

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

(* And ** represent a bond, * represents a bond with Y.)

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

(* And ** represent a bond, * represents a bond with Y.)

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

(* And ** represent a bond, * represents a bond with Y.)

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

(* And ** represent a bond, * represents a bond with Y.)

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

(* And ** represent a bond, * represents a bond with Y.)

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

(* And ** represent a bond, * represents a bond with Y.)

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

(* And ** represent a bond, * represents a bond with Y.)

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

(* And ** represent a bond, * represents a bond with Y.)

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

(* And ** represent a bond, * represents a bond with Y.)

Ｙで表される脂環式炭化水素基としては、好ましくは式（Ｙ１）〜式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）〜式（Ｙ４３）のいずれかで表される基であり、より好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ１６）、式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）、式（Ｙ４０）、式（Ｙ４２）又は式（Ｙ４３）で表される基であり、さらに好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）、式（Ｙ４０）、式（Ｙ４２）又は式（Ｙ４３）で表される基である。
Ｙで表される脂環式炭化水素基が式（Ｙ２８）〜式（Ｙ３５）、式（Ｙ３９）、式（Ｙ４０）、式（Ｙ４２）又は式（Ｙ４３）等の酸素原子を有するスピロ環である場合には、２つの酸素原子間のアルカンジイル基は、１以上のフッ素原子を有することが好ましい。また、ケタール構造に含まれるアルカンジイル基のうち、酸素原子に隣接するメチレン基には、フッ素原子が置換されていないのが好ましい。 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 the formulas (Y12) to (Y35) and the formulas (Y39) to (Y43). * Represents a bond with ^{L b1.}

The alicyclic hydrocarbon group represented by Y is preferably Formula (Y1) to Formula (Y20), Formula (Y26), Formula (Y27), Formula (Y30), Formula (Y31), Formula (Y39). A group represented by any of the formulas (Y43), more preferably formulas (Y11), formulas (Y15), formulas (Y16), formulas (Y20), formulas (Y26), formulas (Y27), formulas. (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43), more preferably formula (Y11), formula (Y15), formula. (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43). ..
The alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom of the formulas (Y28) to (Y35), formula (Y39), formula (Y40), formula (Y42) or formula (Y43). In some cases, the alkylandyl group between the two oxygen atoms preferably has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

Examples of the substituent of the methyl group represented by Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, and-(. CH ₂ ) _ja- CO-O-R ^b1 group or-(CH ₂ ) _ja- O-CO-R ^b1 group (in the formula, R ^b1 is an alkyl group having 1 to 16 carbon atoms and 3 to 16 carbon atoms. It represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group in which they are combined. Ja represents an integer of 0 to 4. The alkyl group and the alicyclic carbonization. _{-CH 2-} contained in the hydrogen group may be replaced by -O-, -S (O) _2- or -CO-, the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon. The hydrogen atom contained in the group may be replaced with a hydroxy group or a fluorine atom.) And the like.
As the substituent of the alicyclic hydrocarbon group represented by Y, an alkyl group having 1 to 16 carbon atoms which may be substituted with a halogen atom, a hydroxy group or a hydroxy group (-CH _{2 contained in the alkyl group).} -May be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, and 7 to 21 carbon atoms. Aralkyl group, glycidyloxy group,-(CH ₂ ) _ja- CO-O-R ^b1 group or-(CH ₂ ) _ja- O-CO-R ^b1 group (in the formula, R ^{b1 has 1 to} 16 carbon atoms. It represents an alkyl group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. Ja represents an integer of 0 to 4. _{The -CH 2-} contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -S (O) _2- or -CO-, and the alkyl group and the alicyclic hydrocarbon group may be replaced. The hydrocarbon group and the hydrogen atom contained in the aromatic hydrocarbon group may be replaced with a hydroxy group or a fluorine atom.) And the like.

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. The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples thereof include a methylcyclohexyl group and a dimethylcyclohexyl group. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms, and more preferably 3 to 10 carbon atoms.
Examples of the aromatic hydrocarbon group include an aryl group such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group include a trill group, a xsilyl group, and a cumenyl group. , Mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and the like, and aromatics having an alicyclic hydrocarbon group. Examples of the hydrocarbon group include a p-cyclohexylphenyl group and a p-adamantylphenyl group. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10.
Examples of the alkyl group 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, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group and a nonyl group. Examples include a group, a decyl group, an undecyl group, a dodecyl group and the like. The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and further preferably 1 to 4 carbon atoms.
Examples of the alkyl group substituted with the hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group and a naphthylethyl group.
_{Examples of the group in which -CH 2-} contained in the alkyl group is replaced with -O-, -S (O) _2- or -CO-, etc. include an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or these. Examples include a group that combines.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group. The alkoxy group has preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and further preferably 1 to 4 carbon atoms.
Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group and the like. The alkoxycarbonyl group has preferably 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group and the like. The alkylcarbonyl group preferably has 2-12 carbon atoms, more preferably 2-6 carbon atoms, and even more preferably 2-4 carbon atoms.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like. The alkylcarbonyloxy group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms.
Examples of the combined group include a group combining an alkoxy group and an alkyl group, a group combining an alkoxy group and an alkoxy group, a group combining an alkoxy group and an alkylcarbonyl group, and an alkoxy group and an alkylcarbonyloxy group. Examples include a group in which the above are combined.
Examples of the group in which the alkoxy group and the alkyl group are combined include an alkoxyalkyl group such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group and an ethoxymethyl group. The alkoxyalkyl group has preferably 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms.
Examples of the group in which the alkoxy group and the alkoxy group are combined include an alkoxyalkoxy group such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, and an ethoxyethoxy group. The alkoxyalkoxy group has preferably 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and further preferably 2 to 4 carbon atoms.
Examples of the group in which the alkoxy group and the alkylcarbonyl group are combined include an alkoxyalkylcarbonyl group such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group and an ethoxypropionyl group. The alkoxyalkylcarbonyl group preferably has 3 to 13 carbon atoms, more preferably 3 to 7 carbon atoms, and even more preferably 3 to 5 carbon atoms.
Examples of the group in which the alkoxy group and the alkylcarbonyloxy group are combined include an alkoxyalkylcarbonyloxy group such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, and an ethoxypropionyloxy group. The alkoxyalkylcarbonyloxy group preferably has 3 to 13 carbon atoms, more preferably 3 to 7 carbon atoms, and even more preferably 3 to 5 carbon atoms.
_{The groups in which -CH 2-} contained in the alicyclic hydrocarbon group is replaced by -O-, -S (O) _2- or -CO-, etc. are represented by the formulas (Y12) to (Y35) and (Y39). ) ~ Groups represented by the formula (Y43) and the like.

Examples of Y include the following.

Y is preferably an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and more preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent. It is a hydrocarbon group, more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and even more preferably an adamantyl group which may have a substituent. _{, -CH 2-} constituting the alicyclic hydrocarbon group or adamantyl group may be replaced with -CO-, -S (O) _{2- or -CO-.} Specifically, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by the formulas (Y42) and the formulas (Y100) to (Y114).

Examples of the anion in the salt represented by the formula (B1) include anions represented by the formulas (B1-A-1) to (B1-A-59) [hereinafter, "anions (B1-A)" according to the formula number. -1) ”and so on. ] Are preferable, and formulas (B1-A-1) to (B1-A-4), formulas (B1-A-9), formulas (B1-A-10), formulas (B1-A-24) to formulas (B1-A-24) to formulas. (B1-A-33), formulas (B1-A-36) to formulas (B1-A-40), formulas (B1-A-47) to formulas (B1-A-59). Anions are more preferred.

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

Here, R ^{i2 to} R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, independently of each other. ^Ri8 is formed, for example, by a chain hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. Group, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. ^LA41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q ^b1 and Q ^b2 have the same meanings as described above.
Specific examples of the anion in the salt represented by the formula (B1) include the anion described in JP-A-2010-204646.

Preferred examples of the anion in the salt represented by the formula (B1) include anions represented by the formulas (B1a-1) to (B1a-38).

Among them, equations (B1a-1) to (B1a-3), equations (B1a-7) to (B1a-16), equations (B1a-18), equations (B1a-19), equations (B1a-22). )-Anion represented by any of the formulas (B1a-38) is preferable.

Examples of the Z1 ⁺ organic cation 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 aryl sulfonium cation is more preferable.

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

特に、Ｒ^b9〜Ｒ^b12の脂環式炭化水素基は、好ましくは炭素数３〜１８、より好ましくは炭素数４〜１２である。
水素原子が脂肪族炭化水素基で置換された脂環式炭化水素基としては、メチルシクロヘキシル基、ジメチルシクロへキシル基、２−メチルアダマンタン−２−イル基、２−エチルアダマンタン−２−イル基、２−イソプロピルアダマンタン−２−イル基、メチルノルボルニル基、イソボルニル基等が挙げられる。水素原子が脂肪族炭化水素基で置換された脂環式炭化水素基においては、脂環式炭化水素基と脂肪族炭化水素基との合計炭素数が好ましくは２０以下である。
フッ化アルキル基とは、フッ素原子を有する炭素数１〜１２のアルキル基を表し、フルオロメチル基、ジフルオロメチル基、トリフルオロメチル基、ペルフルオロブチル等が挙げられる。フッ化アルキル基の炭素数は、好ましくは１〜９であり、より好ましくは１〜６であり、さらに好ましくは１〜４である。
芳香族炭化水素基としては、フェニル基、ビフェニル基、ナフチル基、フェナントリル基等のアリール基が挙げられる。芳香族炭化水素基は、鎖式炭化水素基又は脂環式炭化水素基を有していてもよく、炭素数１〜１８の鎖式炭化水素基を有する芳香族炭化水素基（トリル基、キシリル基、クメニル基、メシチル基、ｐ−エチルフェニル基、ｐ−ｔｅｒｔ−ブチルフェニル基、２，６−ジエチルフェニル基、２−メチル−６−エチルフェニル基等）、及び炭素数３〜１８の脂環式炭化水素基を有する芳香族炭化水素基（ｐ−シクロへキシルフェニル基、ｐ−アダマンチルフェニル基等）等が挙げられる。なお、芳香族炭化水素基が、鎖式炭化水素基又は脂環式炭化水素基を有する場合は、炭素数１〜１８の鎖式炭化水素基及び炭素数３〜１８の脂環式炭化水素基が好ましい。
水素原子がアルコキシ基で置換された芳香族炭化水素基としては、ｐ−メトキシフェニル基等が挙げられる。
水素原子が芳香族炭化水素基で置換された鎖式炭化水素基としては、ベンジル基、フェネチル基、フェニルプロピル基、トリチル基、ナフチルメチル基、ナフチルエチル基等のアラルキル基が挙げられる。
アルコキシ基としては、メトキシ基、エトキシ基、プロポキシ基、ブトキシ基、ペンチルオキシ基、ヘキシルオキシ基、ヘプチルオキシ基、オクチルオキシ基、デシルオキシ基及びドデシルオキシ基等が挙げられる。
アルキルカルボニル基としては、アセチル基、プロピオニル基及びブチリル基等が挙げられる。
ハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子等が挙げられる。
アルキルカルボニルオキシ基としては、メチルカルボニルオキシ基、エチルカルボニルオキシ基、プロピルカルボニルオキシ基、イソプロピルカルボニルオキシ基、ブチルカルボニルオキシ基、ｓｅｃ−ブチルカルボニルオキシ基、ｔｅｒｔ−ブチルカルボニルオキシ基、ペンチルカルボニルオキシ基、ヘキシルカルボニルオキシ基、オクチルカルボニルオキシ基及び２−エチルヘキシルカルボニルオキシ基等が挙げられる。
Ｒ^b4とＲ^b5とが互いに結合してそれらが結合する硫黄原子と一緒になって形成する環は、単環式、多環式、芳香族性、非芳香族性、飽和及び不飽和のいずれの環であってもよい。この環は、炭素数３〜１８の環が挙げられ、好ましくは炭素数４〜１８の環である。また、硫黄原子を含む環は、３員環〜１２員環が挙げられ、好ましくは３員環〜７員環であり、例えば下記の環が挙げられる。＊は結合手を表す。

Ｒ^b9とＲ^b10とが一緒になって形成する環は、単環式、多環式、芳香族性、非芳香族性、飽和及び不飽和のいずれの環であってもよい。この環は、３員環〜１２員環が挙げられ、好ましくは３員環〜７員環である。例えば、チオラン−１−イウム環（テトラヒドロチオフェニウム環）、チアン−１−イウム環、１，４−オキサチアン−４−イウム環等が挙げられる。
Ｒ^b11とＲ^b12とが一緒になって形成する環は、単環式、多環式、芳香族性、非芳香族性、飽和及び不飽和のいずれの環であってもよい。この環は、３員環〜１２員環が挙げられ、好ましくは３員環〜７員環である。オキソシクロヘプタン環、オキソシクロヘキサン環、オキソノルボルナン環、オキソアダマンタン環等が挙げられる。

In equations (b2-1) to (b2-4),
R ^{b4 to} R ^b6 independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms. The hydrogen atom contained in the chain hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. It may be substituted, and the hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted, and the hydrogen atom is a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkyl fluoride group having 1 to 12 carbon atoms or carbon. It may be substituted with an alkoxy group of numbers 1-12.
R ^b4 and R ^b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and −CH ₂ − contained in the ring is −O−, −S− or −O−, −S− or. It may be replaced with −CO−.
R ^b7 and R ^b8 independently represent a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.
When m2 is 2 or more, the plurality of R ^b7s may be the same or different, and when n2 is 2 or more, the plurality of R ^b8s may be the same or different.
R ^b9 and R ^b10 independently represent a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and −CH ₂ − contained in the ring may be −O−, −S− or −O−, −S− or. It may be replaced with −CO−.
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. The contained 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 may be an alkoxy group having 1 to 12 carbon atoms or 1 carbon atom. It may be substituted with ~ 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may form a ring including −CH—CO− to which they are bonded to each other, and −CH ₂₋ contained in the ring is −O−, −S. It may be replaced with − or −CO−.
R ^{b13 to} R ^b18 independently represent a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, a plurality of R ^b13s are the same or different, when p2 is 2 or more, a plurality of R ^b14s are the same or different, and when q2 is 2 or more, a plurality of R ^b15s are the same or different. when r2 is 2 or more, plural R ^b16 same or different, when s2 is 2 or more, plural R ^b17 same or different, when t2 is 2 or more, plural R ^b18 same or different different.
The aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group.
Chain hydrocarbon groups include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Can be mentioned.
In particular, ^{the chain hydrocarbon groups of R b9 to} R ^b12 preferably have 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclo. Cycloalkyl groups such as heptyl group, cyclooctyl group and cyclodecyl group can be mentioned. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups.

In particular, ^{the alicyclic hydrocarbon groups of R b9 to} R ^b12 preferably have 3 to 18 carbon atoms, and more preferably 4 to 12 carbon atoms.
The alicyclic hydrocarbon group in which the hydrogen atom is substituted with an aliphatic hydrocarbon group includes a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, and a 2-ethyladamantan-2-yl group. , 2-Isopropyl adamantan-2-yl group, methylnorbornyl group, isobornyl group and the like. In the alicyclic hydrocarbon group in which the 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.
The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms having a fluorine atom, and examples thereof include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and perfluorobutyl. The alkyl fluoride group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, and further preferably 1 to 4 carbon atoms.
Examples of the aromatic hydrocarbon group include an aryl group such as a phenyl group, a biphenyl group, a naphthyl group and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group having a chain hydrocarbon group having 1 to 18 carbon atoms (trill group, xylyl group). Group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and fats with 3 to 18 carbon atoms Examples thereof include aromatic hydrocarbon groups having a cyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.). When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms Is preferable.
Examples of the aromatic hydrocarbon group in which the hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group.
Examples of the chain hydrocarbon group in which the hydrogen atom is substituted with an aromatic hydrocarbon group include an aralkyl group 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 a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
The alkylcarbonyloxy group includes a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, and a pentylcarbonyloxy group. , Hexylcarbonyloxy group, octylcarbonyloxy group, 2-ethylhexylcarbonyloxy group and the like.
Rings formed by R ^b4 and R ^b5 bonding to each other and together with the sulfur atoms to which they bond can be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. It may be a ring of. Examples of this ring include a ring having 3 to 18 carbon atoms, preferably a ring having 4 to 18 carbon atoms. Further, the ring containing a sulfur atom may be 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. * Represents a bond.

The ^{ring formed by R b9} and R ^b10 together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. For example, a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, a 1,4-oxatian-4-ium ring and the like can be mentioned.
The ^{ring formed by R b11} and R ^b12 together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be 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 cations (b2-1) to cations (b2-4), the cation (b2-1) is preferable.
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.

酸発生剤（Ｂ）は、上述のアニオン及び上述の有機カチオンの組合せであり、これらは任意に組合せることができる。酸発生剤（Ｂ）としては、好ましくは式（Ｂ１ａ−１）〜式（Ｂ１ａ−３）、式（Ｂ１ａ−７）〜式（Ｂ１ａ−１６）、式（Ｂ１ａ−１８）、式（Ｂ１ａ−１９）、式（Ｂ１ａ−２２）〜式（Ｂ１ａ−３８）のいずれかで表されるアニオンと、カチオン（ｂ２−１）、カチオン（ｂ２−３）又はカチオン（ｂ２−４）との組合せが挙げられる。

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 Formulas (B1a-1) to (B1a-3), Formulas (B1a-7) to Formulas (B1a-16), Formulas (B1a-18), Formulas (B1a-). 19), the combination of the anion represented by any of the formulas (B1a-22) to (B1a-38) and the cation (b2-1), the cation (b2-3) or the cation (b2-4) Can be mentioned.

Examples of the acid generator (B) are preferably those represented by the formulas (B1-1) to (B1-56), and among them, those containing an arylsulfonium cation are preferable, and the acid generator (B) is preferably represented by the formula (B1-1). -Formula (B1-3), Formula (B1-5) -Formula (B1-7), Formula (B1-11) -Formula (B1-14), Formula (B1-20) -Formula (B1-26), Those represented by the formulas (B1-29) and the formulas (B1-31) to (B1-56) are particularly preferable.

When the salt (I) and the acid generator (B) are contained as the acid generator, the ratio of the contents 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.
In the resist composition of the present invention, the total content of the acid generator is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 3 parts by mass or more, with respect to 100 parts by mass of the resin (A) described later. It is 40 parts by mass or less.

<Resist composition>
The resist composition of the present invention contains an acid generator containing a salt (I) and a resin having an acid unstable group (hereinafter, may be referred to as "resin (A)"). Here, the "acid-unstable group" has a leaving group, and the leaving group is eliminated by contact with an acid, and the constituent unit has a hydrophilic group (for example, a hydroxy group or a carboxy group). It means a group to be converted into a unit.
The resist composition of the present invention preferably contains a quencher (hereinafter, may be referred to as "citric acid (C)") such as a salt that generates an acid having a weaker acidity than the acid generated from the acid generator. , It is preferable to contain a solvent (hereinafter sometimes referred to as "solvent (E)").

<Resin (A)>
The resin (A) has a structural unit having an acid unstable group (hereinafter, may be referred to as “structural unit (a1)”). The resin (A) preferably further contains a structural unit other than the structural unit (a1). The structural unit other than the structural unit (a1) includes a structural unit having no acid-labile group (hereinafter, may be referred to as “structural unit (s)”), a structural unit (a1), and a structural unit other than the structural unit (s). Structural unit (for example, a structural unit having a halogen atom described later (hereinafter sometimes referred to as "structural unit (a4)"), and a structural unit having a non-eliminating 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^a２及びＲ^a3は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数２〜８のアルケニル基、炭素数３〜２０の脂環式炭化水素基、炭素数６〜１８の芳香族炭化水素基又はこれらを組み合わせた基を表すか、Ｒ^a1及びＲ^a2は互いに結合してそれらが結合する炭素原子とともに炭素数３〜２０の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 unstable group (hereinafter, may be referred to as “monomer (a1)”).
The acid-unstable group contained in the resin (A) is a group represented by the formula (1) (hereinafter, also referred to as a group (1)) and / or a group represented by the formula (2) (hereinafter, a group (2). ) Is also preferable.

[In the formula (1), R ^a1 , R ^a2, and R ^a3 are independently alkyl groups having 1 to 8 carbon atoms, alkenyl groups having 2 to 8 carbon atoms, and alicyclic hydrocarbons having 3 to 20 carbon atoms. Represents a group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, or R ^a1 and R ^a2 are alicyclic hydrocarbons having 3 to 20 carbon atoms together with carbon atoms to which they are bonded to each other. Form a hydrogen group.
ma and na independently represent 0 or 1, and at least one of ma and na represents 1.
* Represents a bond. ]

[In the 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. Represented, 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 and X to which they are bonded, and are contained 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. ]

Ｒ^ａ１、Ｒ^ａ２及びＲ^ａ３における芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニル基、フェナントリル基等のアリール基が挙げられる。
組み合わせた基としては、上述したアルキル基と脂環式炭化水素基とを組み合わせた基（例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、シクロヘキシルメチル基、アダマンチルメチル基、アダマンチルジメチル基、ノルボルニルエチル基等のアルキルシクロアルキル基又はシクロアルキルアルキル基）、ベンジル基等のアラルキル基、アルキル基を有する芳香族炭化水素基（ｐ−メチルフェニル基、ｐ−ｔｅｒｔ−ブチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、２，６−ジエチルフェニル基、２−メチル−６−エチルフェニル基等）、脂環式炭化水素基を有する芳香族炭化水素基（ｐ−シクロヘキシルフェニル基、ｐ−アダマンチルフェニル基等）、フェニルシクロヘキシル基等のアリール−シクロアルキル基等が挙げられる。 好ましくは、ｍａは０であり、ｎａは１である。
Ｒ^a1及びＲ^a2が互いに結合して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 , Ra ² and Ra 3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group and the like.
The alkenyl groups in R ^a1 , R ^a2 and R ^a3 include ethenyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, tert-butenyl group, pentenyl group, hexenyl group, heptenyl group, octynyl group and isooctynyl group. Nonenyl group is mentioned.
The alicyclic hydrocarbon group in R ^a1 , R ^a2 and Ra ³ may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* indicates a bond). The alicyclic hydrocarbon groups of R ^a1 , R ^a2 and R ^a3 have preferably 3 to 16 carbon atoms.

Examples of the aromatic hydrocarbon group in R ^a1 , Ra ² and Ra ³ include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group.
As the combined group, a group combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl group) Alkylcycloalkyl group such as dimethyl group, norbornylethyl group or cycloalkylalkyl group), aralkyl group such as benzyl group, aromatic hydrocarbon group having alkyl group (p-methylphenyl group, p-tert-butylphenyl) Aromatic hydrocarbon group (p-) having an alicyclic hydrocarbon group, a group, a trill group, a xsilyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, etc.) Cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl group such as phenylcyclohexyl group, etc. can be mentioned. Preferably, ma is 0 and na is 1.
^{Examples of -C (R a1} ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R a ² 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' , R ^a2' and 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 mentioned in ^{Ra 1} , Ra ² and Ra ^3.
Examples of the aromatic hydrocarbon group include an aryl group such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group and a phenanthryl group.
As the combined group, a group combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl group) Alkylcycloalkyl group such as dimethyl group, norbornylethyl group or cycloalkylalkyl group), aralkyl group such as benzyl group, aromatic hydrocarbon group having alkyl group (p-methylphenyl group, p-tert-butylphenyl) Aromatic hydrocarbon group (p-) having an alicyclic hydrocarbon group, a group, a trill group, a xsilyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, etc.) Cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl group such as phenylcyclohexyl group, etc. can be mentioned.
When R ^a2'and R ^a3' are bonded to each other to form a heterocycle together with the carbon atom and X to which they are bonded, -C (R ^a1' ) (R ^a2' )-X-R ^a3'is as follows. The basis of. * Represents a bond.

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

Examples of the group (1) include the following groups.
^{A group in which R a1} , R ^a2, and R ^a3 are alkyl groups in the formula (1), ma = 0, and na = 1. As the group, a tert-butoxycarbonyl group is preferable.
In formula (1), R ^a1 and R ^a2 form an adamantyl group together with the carbon atom to which they are bonded, and R ^a3 is an alkyl group, ma = 0, and na = 1. ..
In the formula (1), R ^a1 and R ^a2 are independently alkyl groups, 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 unstable group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid unstable group.

Among the (meth) acrylic monomers having an acid unstable 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、水素原子、ハロゲン原子又はハロゲン原子を有していてもよい炭素数１〜６のアルキル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基、炭素数６〜１８の芳香族炭化水素基又はこれらを組み合わせた基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数２〜８のアルケニル基、炭素数３〜１８の脂環式炭化水素基、炭素数６〜１８の芳香族炭化水素基又はこれらを組合せることにより形成される基を表す。
ｍ１は０〜１４のいずれかの整数を表す。
ｎ１は０〜１０のいずれかの整数を表す。
ｎ１’は０〜３のいずれかの整数を表す。］ 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, may be referred to as a structural unit (a1-0)). , Structural unit represented by the formula (a1-1) (hereinafter, may be referred to as structural unit (a1-1)) or structural unit represented by the formula (a1-2) (hereinafter, structural unit (a1-). 2) may be mentioned. More preferably, it is at least one structural unit selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). These may be used alone or in combination of two or more.

[In the formula (a1-0), the formula (a1-1) and the formula (a1-2),
L ^{a01, L a1} and ^{L a2} each independently, -O- or _{* -O- (CH 2) k1 -CO} -O- the stands, k1 represents an integer of 1-7, and * Represents a bond with −CO−.
R ^a01 , R ^a4 and R ^a5 represent an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom.
R ^a02 , R ^a03 and R ^a04 independently contain an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or these. Represents a combined group.
R ^a6 and R ^a7 independently have an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic group having 6 to 18 carbon atoms. Represents a hydrocarbon group or a group formed by combining these groups.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1'represents an integer of 0 to 3. ]

R ^a01 , R ^a4 and R ^a5 are preferably a hydrogen atom or a methyl group, and more preferably a methyl group.
L ^{a01, L a1} and ^{L a2} are preferably oxygen atom or _{* -O- (CH 2) k01 -CO} -O- and is (however, k01 is preferably either 1 to 4 integer, more preferably Is 1.), More preferably an oxygen atom.
Examples of the alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^{a7 and the group combining these groups include R a1 of} the formula (1). Groups similar to those mentioned in R ^a2 and R ^{a3 can be mentioned.}
The alkyl group in R ^a02 , R ^a03 , and R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
The alkyl group in R ^a6 and R ^a7 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group or a t-butyl group, and further preferably an ethyl group or an isopropyl group. Or it is a t-butyl group.
Alkenyl group for R ^a6 and R ^a7 is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably ethenyl, propenyl group, isopropenyl group or butenyl group.
The alicyclic hydrocarbon groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 have preferably 5 to 12 carbon atoms, more preferably 5 to 10 carbon atoms.
The ^{number of carbon atoms of the aromatic hydrocarbon groups of R a02} , R ^a03 , R ^a04 , R ^a6 and R ^a7 is preferably 6 to 12, and more preferably 6 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 with these alkyl groups and the alicyclic hydrocarbon group.
The group in which the alkyl group and the aromatic hydrocarbon group are combined preferably has a total carbon number of 18 or less in which the alkyl group and the aromatic hydrocarbon group are combined.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group.
^Ra04 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.
R ^a6 and R ^a7 are preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably a methyl group or an ethyl group. It is an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group or a naphthyl group, and more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group or a phenyl group.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1'is preferably 0 or 1.

The structural unit (a1-0) is, for example, a structural unit represented by any one of the formulas (a1-0-1) to (a1-0-18) and R ^{a01 in the structural unit (a1-0).} Examples of structural units in which the corresponding methyl group is replaced with a hydrogen atom include formulas (a1-0-1) to (a1-0-10), formulas (a1-0-13), and formulas (a1-0-14). ) Is preferred.

Examples of the structural unit (a1-1) include structural units derived from the monomers described in JP-A-2010-204646. Among them, a methyl group corresponding to ^{R a4} in Formula (a1-1-1) structural units and structural units represented by any one of the - formula (a1-1-7) (a1-1) is replaced by a hydrogen atom Structural units are preferable, and structural units represented by any of the formulas (a1-1-1) to (a1-1-4) are more preferable.

The structural unit (a1-2) corresponds to the structural unit represented by any of the formulas (a1-2-1) to (a1-2-12) and R ^{a5 in the structural unit (a1-2).} Structural units in which a methyl group is replaced with a hydrogen atom include formulas (a1-2-2), formulas (a1-2-5), formulas (a1-2-6) and formulas (a1-2-10) to. The structural unit represented by any of the formula (a1-2-12) is preferable.

When the resin (A) contains the structural unit (a1-0), the content thereof is usually 5 to 60 mol%, preferably 5 to 50 mol%, based on all the structural units of the resin (A). Yes, more preferably 10-40 mol%.
When the resin (A) contains a structural unit (a1-1) and / or a structural unit (a1-2), the total content of these is usually 10 to 95 mol with respect to the total structural unit of the resin (A). %, Preferably 15-90 mol%, more preferably 20-85 mol%, even more preferably 25-70 mol%, even more preferably 30-70 mol%.

［式（ａ１−４）中、
Ｒ^a32は、水素原子、ハロゲン原子、又は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^a33は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜１２のアルコキシアルキル基、炭素数２〜１２のアルコキシアルコキシ基、炭素数２〜４のアルキルカルボニル基、炭素数２〜４のアルキルカルボニルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
Ａ^a30は、単結合又は^＊−Ｘ^a31−（Ａ^a32−Ｘ^a32）_nc−を表し、＊は−Ｒ^a32が結合する炭素原子との結合部位を表す。
Ａ^a32は、炭素数１〜６のアルカンジイル基を表す。
Ｘ^a31及びＸ^a32は、それぞれ独立に、−Ｏ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−を表す。
ｎｃは、０又は１を表す。
ｌａは０〜４のいずれかの整数を表す。ｌａが２以上のいずれかの整数である場合、複数のＲ^a33は互いに同一であっても異なってもよい。
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 structural units represented by the formula (a1-4) (hereinafter, may be referred to as “structural unit (a1-4)”). ..

[In equation (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, and a carbon number of carbon atoms. It represents an alkylcarbonyl group of 2 to 4, an alkylcarbonyloxy group of 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a30 represents a single bond or ^* −X ^a31 − (A ^a32 −X ^a32 ) _nc −, and * represents a binding site with a carbon atom to which ^{−R a32 is bonded.}
A ^a32 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a31 and X ^a32 independently represent -O-, -CO-O- or -O-CO-, respectively.
nc represents 0 or 1.
la represents any integer from 0 to 4. When la is any integer of 2 or more, the plurality of Ra ^33s may be the same 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 Then, together with -CO- to which they are bonded, a divalent hydrocarbon group having 2 to 20 carbon atoms is formed, and the hydrocarbon group and the −CH ₂ − contained in the divalent hydrocarbon group are − It may be replaced by O- or -S-. ]

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 in Ra32} include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, and 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, 2,2,3,3,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluoro Hexyl group is mentioned.
R ^a32 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
^Examples of the alkyl group in Ra33 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 in Ra33 include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group.
^Examples of the alkoxyalkyl group in Ra33 include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group.
^Examples of the alkoxyalkoxy group in Ra33 include methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group, propoxymethoxy group, isopropoxymethoxy group, butoxymethoxy group, sec-butoxymethoxy group, and tert-butoxymethoxy group. Can be mentioned. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethyl group or an ethoxyethyl group.
^{Examples of the alkylcarbonyl group in Ra33} include an acetyl group, a propionyl group, a butyryl group and the like. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group.
The alkylcarbonyloxy group in R ^a33, acetyloxy group, and a propionyloxy group and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group.
R ^a33 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, and is preferably a fluorine atom, an iodine atom, a hydroxy group or a methyl. A group, a methoxy group, an ethoxy group, an ethoxyethoxy group or an ethoxymethoxy group is more preferable, and a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group is further preferable.

* -X ^a31- (A ^a32- X ^a32 ) As _nc- , * -O-, * -CO-O-, * -O-CO-, * -CO-O-A ^{a32-CO-O-, * -O-CO-A a32 -O} -, * - O-A a32 -CO-O -, * - CO-O-A a32 -O-CO -, * - O-CO-A a32 -O-CO -, Can be mentioned. Of these, * ^{-CO-O-, * -CO-O-A a32-} CO-O- or * -O-A ^a32- CO-O- are preferable.

The alkanediyl group includes a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-. 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2 -Methylbutane-1,4-diyl group and the like can be mentioned.
A ^a32 is preferably a methylene group or an ethylene group.

A ^a30 is preferably single bond, * -CO-O- or * -CO-O-A ^a32- CO-O-, and is preferably single bond, * -CO-O- or * -CO-O-CH. _{It is more preferably 2-} CO-O-, and even more preferably a single bond or * -CO-O-.

芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニル基、フェナントリル基等のアリール基等が挙げられる。
組み合わせた基としては、上述したアルキル基と脂環式炭化水素基とを組み合わせた基（例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、シクロヘキシルメチル基、アダマンチルメチル基、アダマンチルジメチル基、ノルボルニルエチル基等のアルキルシクロアルキル基又はシクロアルキルアルキル基）、ベンジル基等のアラルキル基、アルキル基を有する芳香族炭化水素基（ｐ−メチルフェニル基、ｐ−ｔｅｒｔ−ブチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、２，６−ジエチルフェニル基、２−メチル−６−エチルフェニル基等）、脂環式炭化水素基を有する芳香族炭化水素基（ｐ−シクロヘキシルフェニル基、ｐ−アダマンチルフェニル基等）、フェニルシクロヘキシル基等のアリール−シクロアルキル基等が挙げられる。特に、Ｒ^a36としては、炭素数１〜１８のアルキル基、炭素数３〜１８の脂環式炭化水素基、炭素数６〜１８の芳香族炭化水素基又はこれらを組み合わせることにより形成される基が挙げられる。 la is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0.
As the hydrocarbon group for R ^a34, R ^a35 and R ^a36, an alkyl group, an alicyclic hydrocarbon group, aromatic hydrocarbon group and a group formed by combining these.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group and the like.
The alicyclic hydrocarbon group may be either a monocyclic or polycyclic group. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* indicates a binding site).

Examples of the aromatic hydrocarbon group include an aryl group such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group and a phenanthryl group.
As the combined group, a group combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl group) Alkylcycloalkyl group such as dimethyl group, norbornylethyl group or cycloalkylalkyl group), aralkyl group such as benzyl group, aromatic hydrocarbon group having alkyl group (p-methylphenyl group, p-tert-butylphenyl) Aromatic hydrocarbon group (p-) having an alicyclic hydrocarbon group, a group, a trill group, a xsilyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, etc.) Cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl group such as phenylcyclohexyl group, etc. can be mentioned. In particular, ^Ra36 includes an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these groups. Can be mentioned.

R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a methyl group or an ethyl group.
The hydrocarbon group of R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination 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 the alicyclic hydrocarbon group in ^{Ra36 are preferably unsubstituted.} Aromatic hydrocarbon group for R ^a36 is an aromatic ring preferably has an aryloxy group having 6 to 10 carbon atoms.

^{-OC (R a34) (R a35} ) -O-R a36 in the structural unit (a1-4) is desorbed by contact with an acid (e.g. p- toluenesulfonic acid) to form a hydroxy group.
^{-OC (R a34) (R a35} ) -O-R a36 is preferably bonded to the o- or p- position of the benzene ring, and more preferably binds to the p- position.

Examples of the structural unit (a1-4) include a structural unit derived from a monomer described in JP-A-2010-204646. Preferably, hydrogen atom corresponding to ^{R a32} in equation (a1-4-1) represented respectively to Formula (a1-4-18) structural units and structural units (a1-4) is replaced by a methyl group structure Units are mentioned, and more preferably, the formulas (a1-4-1) to (a1-4-5), formulas (a1-4-10), formulas (a1-4-13), and formulas (a1-4) are used. The structural units represented by -14) can be mentioned.

When the resin (A) has a structural unit (a1-4), the content thereof is preferably 10 to 95 mol% with respect to the total of all the structural units of the resin (A), 15 to 90. It is more preferably mol%, further preferably 20 to 85 mol%, even more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol%.

式（ａ１−５）中、
Ｒ^a8は、ハロゲン原子を有してもよい炭素数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, may be referred to as “structural unit (a1-5)”). Be done.

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

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable.
Alkyl groups having 1 to 6 carbon atoms which may have a halogen atom include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, fluoromethyl group and trifluoromethyl. Group is mentioned.
In the formula (a1-5), R ^a8 represents a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
Of L ⁵² and L ⁵³ , it is preferable that one is −O− and the other is −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-.

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

When the resin (A) has a structural unit (a1-5), the content thereof is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on all the structural units of the resin (A). , 5-40 mol%, even more preferably 5-30 mol%.

Further, as the structural unit (a1), the following structural units can also be mentioned.

When the resin (A) contains the structural units such as (a1-3-1) to (a1-3-7) described above, the content ratio thereof is 10 to 10 with respect to all the structural units of the resin (A). 95 mol% is preferable, 15 to 90 mol% is more preferable, 20 to 85 mol% is further preferable, 20 to 70 mol% is further more preferable, and 20 to 60 mol% is particularly preferable.

<Structural unit (s)>
The structural unit (s) is derived from a monomer having no acid-labile group (hereinafter, may be referred to as “monomer (s)”). As the monomer for deriving the structural unit (s), a monomer having no acid unstable 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 no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a lactone ring and 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 ray such as a KrF excimer laser (248 nm), an electron beam or EUV (ultraviolet light) is used as an exposure light source, the structural unit (a2) is used. , The structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-A) described later. When an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, and it is more preferable to use a structural unit (a2-1) described later. preferable. As the structural unit (a2), one type may be contained alone, or two or more types may be 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２〜１２のアルコキシアルキル基、炭素数２〜１２のアルコキシアルコキシ基、炭素数２〜４のアルキルカルボニル基、炭素数２〜４のアルキルカルボニルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
Ａ^a50は、単結合又は＊−Ｘ^a51−（Ａ^a52−Ｘ^a52）_nｂ−を表し、＊は−Ｒ^a50が結合する炭素原子との結合手を表す。
Ａ^a52は、炭素数１〜６のアルカンジイル基を表す。
Ｘ^a51及びＸ^a52は、それぞれ独立に、−Ｏ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−を表す。
ｎｂは、０又は１を表す。
ｍｂは０〜４のいずれかの整数を表す。ｍｂが２以上のいずれかの整数である場合、複数のＲ^a51は互いに同一であっても異なってもよい。］ 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, may be referred to as “structural unit (a2-A)”).

[In formula (a2-A),
^Ra50 represents an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, and a carbon number of carbon atoms. It represents an alkylcarbonyl group of 2 to 4, an alkylcarbonyloxy group of 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a50 represents a single bond or ^{* -X a51 - (A a52 -X} a52) nb - represents, * represents a bond to the carbon atom to which -R ^a50 binds.
A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 independently represent -O-, -CO-O- or -O-CO-, respectively.
nb represents 0 or 1.
mb represents any integer from 0 to 4. When mb is any integer of 2 or more, the plurality of Ra ^51s may be the same or different from each other. ]

^Examples of the halogen atom in R ^a50 and R a51 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 Ra50 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group and 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, 2,2,3,3,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluorohexyl Group is mentioned.
R ^a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
^Examples of the alkyl group in Ra51 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. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.
^Examples of the alkoxy group in Ra51 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. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group.
^Examples of the alkoxyalkyl group in Ra51 include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group.
^Examples of the alkoxyalkoxy group in Ra51 include methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group, propoxymethoxy group, isopropoxymethoxy group, butoxymethoxy group, sec-butoxymethoxy group, and tert-butoxymethoxy group. Can be mentioned. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group.
^Examples of the alkylcarbonyl group in Ra51 include an acetyl group, a propionyl group, a butyryl group and the like. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group.
^Examples of the alkylcarbonyloxy group in Ra51 include an acetyloxy group, a propionyloxy group and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group.
R ^a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, and is preferably a fluorine atom, an iodine atom, a hydroxy group or a methyl. A group, a methoxy group, an ethoxy group, an ethoxyethoxy group or an ethoxymethoxy group is more preferable, and a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group is further preferable.

* -X ^a51- (A ^a52- X ^a52 ) _nb- is * -O-, * -CO-O-, * -O-CO-, * -CO-O-A ^{a52-CO-O-, * -O-CO-A a52 -O} -, * - O-A a52 -CO-O -, * - CO-O-A a52 -O-CO -, * - O-CO-A a52 -O-CO -, Can be mentioned. Of these, * ^{-CO-O-, * -CO-O-A a52-} CO-O- or * -O-A ^a52- CO-O- are preferable.

The alkanediyl group includes a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-. 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2 -Methylbutane-1,4-diyl group and the like can be mentioned.
A ^a52 is preferably a methylene group or an ethylene group.

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

The mb is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0.
The hydroxy group is preferably bonded to the ortho-position or para-position of the benzene ring, and more preferably to the para-position.

Examples of the structural unit (a2-A) include monomer-derived structural units described in JP-A-2010-204634 and JP-A-2012-12577.
As the structural unit (a2-A), the structural unit represented by the formulas (a2-2-1) to (a2-2-16) and the formulas (a2-2-1) to (a2-2-16) are used. ^{), The structural unit in which the methyl group corresponding to Ra50} in the structural unit (a2-A) is replaced with a hydrogen atom can be mentioned. The structural unit (a2-A) is represented by a structural unit represented by the formula (a2-2-1), a structural unit represented by the formula (a2-2-3), and a formula (a2-2-6). Structural unit, structural unit represented by the formula (a2-2-8), structural unit represented by the formulas (a2-2-12) to (a2-2-14), and the formula (a2-2-1). ), The structural unit represented by the formula (a2-2-3), the structural unit represented by the formula (a2-2-6), and the structural unit represented by the formula (a2-2-8). Structural unit, in the structural unit represented by the formulas (a2-2-12) to (a2-2-14), the structure in which the methyl group corresponding to ^{Ra50 in the structural unit (a2-A) is replaced with a hydrogen atom.} The unit is preferably a structural unit represented by the formula (a2-2-3), a structural unit represented by the formula (a2-2-8), and formulas (a2-2-12) to (a2-). The structural unit represented by 2-14) and the structural unit represented by the formula (a2-2-3) or the structural unit represented by the formula (a2-2-8), the formulas (a2-2-12) to In the structural unit represented by the formula (a2-2-14), ^{it is more preferable that the methyl group corresponding to Ra50} in the structural unit (a2-A) is replaced with a hydrogen atom, and it is more preferable that the structural unit is a structural unit represented by the formula (a2-A2-A). In the structural unit represented by 2-8) and the structural unit represented by the formula (a2-2-8), ^{the methyl group corresponding to Ra50} in the structural unit (a2-A) is replaced with a hydrogen atom. Is more preferable.

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

式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を表し、
ｋ２は１〜７のいずれかの整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０のいずれかの整数を表す。 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, may be referred to as “structural unit (a2-1)”).

In equation (a2-1),
^La3 represents −O− or * −O− (CH ₂ ) _k2 −CO−O−.
k2 represents any integer from 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 independently represent a hydrogen atom, a methyl group or a hydroxy group, respectively.
o1 represents any integer from 0 to 10.

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

Examples of the structural unit (a2-1) include structural units derived from the monomers described in JP-A-2010-204646. The structural unit represented by any of the formulas (a2-1-1) to (a2-1-6) is preferable, and any of the formulas (a2-1-1) to (a2-1-4) is used. 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 further preferable.

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

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocyclic ring such as β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a fused ring of a monocyclic lactone ring and another ring. But it may be. Preferably, a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)) can be mentioned.

［式（ａ３−１）、式（ａ３−２）、式（ａ３−３）及び式（ａ３−４）中、
Ｌ^ａ４、Ｌ^ａ５及びＬ^ａ６は、それぞれ独立に、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７のいずれかの整数を表す。）で表される基を表す。
Ｌ^ａ７は、−Ｏ−、＊−Ｏ−Ｌ^ａ８−Ｏ−、＊−Ｏ−Ｌ^ａ８−ＣＯ−Ｏ−、＊−Ｏ−Ｌ^ａ８−ＣＯ−Ｏ−Ｌ^ａ９−ＣＯ−Ｏ−又は＊−Ｏ−Ｌ^ａ８−Ｏ−ＣＯ−Ｌ^ａ９−Ｏ−を表す。
Ｌ^ａ８及びＬ^ａ９は、それぞれ独立に、炭素数１〜６のアルカンジイル基を表す。
＊はカルボニル基との結合部位を表す。
Ｒ^ａ１８、Ｒ^ａ１９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。
Ｘ^ａ３は、−ＣＨ_２−又は酸素原子を表す。
Ｒ^ａ２１は炭素数１〜４の脂肪族炭化水素基を表す。
Ｒ^ａ２２、Ｒ^ａ２３及びＲ^ａ２５は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は０〜５のいずれかの整数を表す。
ｑ１は、０〜３のいずれかの整数を表す。
ｒ１は、０〜３のいずれかの整数を表す。
ｗ１は、０〜８のいずれかの整数を表す。
ｐ１、ｑ１、ｒ１及び／又はｗ１が２以上のとき、複数のＲ^ａ２１、Ｒ^ａ２２、Ｒ^ａ２３及び／又はＲ^ａ２５は互いに同一であってもよく、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). One of these may be contained alone, or two or more thereof may be contained.

[In the formula (a3-1), the formula (a3-2), the formula (a3-3) and the formula (a3-4),
L ^a4 , ^{La 5} and ^{La 6} are independently represented by -O- or * -O- (CH ₂ ) _k3 -CO-O- (k3 represents an integer of 1 to 7). Represents a group.
L ^{a7 is, -O -, * - 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-represented.
^{La 8} and ^{La 9} each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* Represents the binding site with the carbonyl group.
R ^a18 , R ^a19 and R ^a20 each independently represent a hydrogen atom or a methyl group.
^Ra24 represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom or a halogen atom which may have a halogen atom.
X ^a3 is, -CH ₂ - represents an or an oxygen atom.
Ra ²¹ represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 each independently represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents any integer from 0 to 5.
q1 represents any integer from 0 to 3.
r1 represents any integer from 0 to 3.
w1 represents any integer from 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 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. Be done.
^{Examples of the halogen atom in Ra24} include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
^Examples of the alkyl group in Ra24 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. Alkyl group of, more preferably methyl group or ethyl group.
^{Alkyl groups having a halogen atom in Ra24} include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and perfluoro. Examples thereof include a hexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.
The ^{alkanediyl group in La8} and ^La9 includes 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, Examples thereof include 4-diyl group and 2-methylbutane-1,4-diyl group.

In the formula (a3-1) ~ formula ^(a3-3), L a4 ^{~L a6} are each independently preferably -O- _{or, * - O- (CH 2)} k3 -CO-O- in, k3 Is an integer of 1 to 4, more preferably -O- and * -O-CH _2- CO-O-, and even 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 independently, preferably an integer of 0 to 2, and more preferably 0 or 1.

（式中、Ｒ^ａ２４、Ｌ^ａ７は、上記と同じ意味を表す。） In the 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, more preferably a hydrogen atom or a methyl group Is.
^Ra25 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 an _{-O -, - O-CH 2} -CO-O- or _-O-C 2 _{H 4} - It is CO-O-.
w1 is preferably an integer of 0 to 2, more preferably 0 or 1.
In particular, the formula (a3-4) is preferably the formula (a3-4)'.

(In the formula, ^Ra24 and ^La7 have the same meanings as above.)

The structural unit (a3) is a structure derived from the monomer described in JP-A-2010-204646, the monomer described in JP-A-2000-122294, and the monomer described in JP-A-2012-41274. The unit is mentioned. The structural unit (a3) includes the formula (a3-1-1), the formula (a3-1-2), the formula (a3-2-1), the formula (a3-2-2), and the formula (a3-3-3). 1), the structural unit represented by any of the formulas (a3-3-2) and the formulas (a3-4-1) to (a3-4-12), and in the structural unit, the formula (a3-1). ) ^R a18 in ~ formula ^{(a3-4), R a19, R} a20 and structural units in which a methyl group is replaced by a hydrogen atom corresponding to R ^a24 are preferred.

When the resin (A) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). , More preferably 10 to 60 mol%.
Further, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) or the structural unit (a3-4) is set with respect to all the structural units of the resin (A), respectively. 5 to 60 mol% is preferable, 5 to 50 mol% is more preferable, and 10 to 50 mol% is further 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 equation (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. ]
Examples of the saturated hydrocarbon group represented by R ⁴² 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。 Chain hydrocarbon groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group. Can be mentioned. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups. Examples thereof include a polycyclic alicyclic hydrocarbon group such as (* indicates 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, and examples thereof include-alkanediyl groups-. Examples thereof include an alicyclic hydrocarbon group, an alicyclic hydrocarbon group, an alkyl group, an alkanediyl group, an alicyclic hydrocarbon group, and an alkyl group.

［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２価の脂肪族飽和炭化水素基を表す。
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 the formula (a4-0), the formula (a4-1), the formula (a4-2), the formula (a4-3) and the formula (a4-4). A structural unit represented by one can be mentioned.

[In equation (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ^4a represents a single bond or a divalent aliphatic saturated hydrocarbon 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. ]

The ^{divalent aliphatic saturated hydrocarbon group in L 4a} includes a linear alkanediyl group such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, and an ethane-1. , 1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group and the like. Alkanediyl group is mentioned.
The perfluoroalkanediyl group in L ^3a includes a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane. -2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane -2,2-diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane -1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane Examples thereof include -2,2-diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
^Examples of the perfluorocycloalkanediyl group in L 3a include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantandiyl group and the like.

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 perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

The structural unit (a4-0), a methyl group corresponding to R ⁵ may be mentioned a structural unit replacing a hydrogen atom in the structural units in the structural units and the following structural units shown below (a4-0).

［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 equation (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH _2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-. You may.
A ^a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by the formula (ag1). However, ^{at least one of A a41} and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent.

[In the formula (ag1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a single bond or a substituent.
X ^a41 and X ^a42 independently represent -O-, -CO-, -CO-O- or -O-CO-, respectively.
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 is a bond with -O-CO-R ^a42 . ]

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式飽和炭化水素基とを組み合わせることにより形成される基が挙げられ、−アルカンジイル基−脂環式飽和炭化水素基、−脂環式飽和炭化水素基−アルキル基、−アルカンジイル基−脂環式飽和炭化水素基−アルキル基等が挙げられる。 ^Examples of the saturated hydrocarbon group in Ra42 include a chain-type saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these.
The chain saturated hydrocarbon group includes a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group and an octadecyl group. Can be mentioned.
Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups. Examples thereof include a polycyclic alicyclic saturated hydrocarbon group such as (* indicates 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 saturated hydrocarbon groups, and a-alkandyl group. -Alicyclic saturated hydrocarbon group, -Alicyclic saturated hydrocarbon group-Alkyl group, -Alkanediyl group-Alicyclic saturated hydrocarbon group-Alkyl group and the like.

［式（ａ−ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、＊−Ｏ−ＣＯ−又は＊−ＣＯ−Ｏ−を表す。
Ａ^a45は、ハロゲン原子を有していてもよい炭素数１〜１７の脂肪族炭化水素基を表す。＊はＲ^a42との結合手を表す。］
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 at least one selected from a halogen atom and a group represented by the formula (ag3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

[In the formula (ag3),
X ^a43 represents an oxygen atom, a carbonyl group, * -O-CO- or * -CO-O-.
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * Represents a bond with ^Ra42. ]
However, in R ^a42- X ^a43- A ^a45 , when R ^a42 does not have a halogen atom, A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms having at least one halogen atom.

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式炭化水素基とを組み合わせることにより形成される基が挙げられ、−アルカンジイル基−脂環式炭化水素基、−脂環式炭化水素基−アルキル基、−アルカンジイル基−脂環式炭化水素基−アルキル基等が挙げられる。 The aliphatic hydrocarbon group in A ^a45 includes a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group and a heptadecyl group. Alkyl groups such as octadecyl groups;
Monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; and decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bond) ) Etc., a polycyclic alicyclic hydrocarbon group can be mentioned.

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, and examples thereof include-alkanediyl groups-. Examples thereof include an alicyclic hydrocarbon group, an alicyclic hydrocarbon group, an alkyl group, an alkanediyl group, an alicyclic hydrocarbon group, and an alkyl group.

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (ag3). ..
When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and further preferably having a carbon number of carbons. It is a perfluoroalkyl group of 1 to 6, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. 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 an aliphatic hydrocarbon group having a group represented by the formula (ag3)} , the total number of R a42 including the number of carbon atoms contained in the group represented by the formula (ag3) is included. The number of carbon atoms is preferably 15 or less, more preferably 12 or less. When the group represented by the formula (ag3) is used as a substituent, the number thereof is preferably one.

［式（ａ−ｇ２）中、
Ａ^a46は、ハロゲン原子を有していてもよい炭素数１〜１７の２価の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）。
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 an aliphatic hydrocarbon having a group represented by the formula ( ^{ag3), R a42} is more preferably a group represented by the formula (ag2).

[In the formula (ag2),
A ^a46 represents a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents **-O-CO- or **-CO-O- (** represents a bond with ^{A a46).}
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of ^{A a46} , A ^a47 and X ^{a44 is 18 or less, and at least one of A a46} and A ^a47 has at least one halogen atom.
* Represents a bond with a carbonyl group. ]

The aliphatic hydrocarbon group of A ^a46 preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.
The aliphatic hydrocarbon group of A ^a47 preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and further preferably A ^a47 has a cyclohexyl group or an adamantyl group.

The preferred structure of the group represented by the formula (ag2) is the following structure (* is a bond with a carbonyl group).

The ^{alkanediyl group in A a41} includes a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. Linear alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, etc. Examples thereof include branched alkanediyl groups such as 2-methylbutane-1,4-diyl group.
^Examples of the substituent in the alkanediyl group of 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 further 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, a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, Examples thereof 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-g1), ^{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 ** represent the bond, respectively, and ** is the bond with -O-CO-R ^a42 .

As the structural unit represented by the formula (a4-1), the methyl group corresponding to ^Ra41 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 replaced structural units.

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

[In equation (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 a fluorine atom having 1 to 20 carbon atoms.
However, the upper limit of the total carbon number of ^{L 44} and R ^{f6 is 21.} ]

^Examples of the alkanediyl group having 1 to 6 carbon atoms of L ⁴⁴ include the same groups as those exemplified for the alkanediyl group in Aa41.
Examples of the saturated hydrocarbon group of R ^f6 include the same groups as those exemplified in ^{R a42.}
The alkanediyl group having 1 to 6 carbon atoms in L ^44, preferably alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.

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

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

[In equation (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 divalent saturated hydrocarbon group having 1 to 18 carbon atoms which may have a fluorine atom.
X ^f12 represents * -O-CO- or * -CO-O- (* represents a bond with ^{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 in the alkanediyl group in the divalent saturated hydrocarbon group of Aa41.
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. It is also a good divalent alicyclic saturated hydrocarbon group, more preferably a perfluoroalkanediyl group.
Examples of the divalent aliphatic hydrocarbon group which may have a fluorine atom include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanjiyl group and a pentandiyl group; a difluoromethylene group, a perfluoroethylene group and a perfluoro Examples thereof include perfluoroalkandyl groups such as propanediyl group, perfluorobutandyl group and perfluoropentanediyl group.
The divalent alicyclic hydrocarbon group which may have a fluorine atom may be either a monocyclic type or a polycyclic type. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantandiyl group, a norbornanediyl group, a perfluoroadamantandiyl group and the like.
Examples of the saturated hydrocarbon group of A ^{f14 and} the saturated hydrocarbon group which may have a fluorine atom include the same groups as those exemplified in ^Ra42. 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, 2,2,3,3,4,5,5,5-Nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group, perfluorooctyl group, etc. Alkyl group, cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, perfluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group, norbornylmethyl group, perfluoroadamantyl group , Perfluoroadamantylmethyl group and the like are preferable.

In the formula (a4-3), L ⁵ is preferably an ethylene group.
The ^{divalent saturated hydrocarbon group of A f13} is preferably a group containing a divalent chain hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. 2-3 divalent chain hydrocarbon groups are more preferred.
The saturated hydrocarbon group of A ^f14 is preferably a group containing a chain hydrocarbon group having 3 to 12 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a chain hydrocarbon group having 3 to 10 carbon atoms. And a group containing an alicyclic hydrocarbon group having 3 to 10 carbon atoms is more 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 the formula (a4-3) include structural units represented by the formulas (a4-1'-1) to (a4-1'-11). ^{A structural unit in which the methyl group corresponding to R f7} in the structural unit (a4-3) is replaced with a hydrogen atom is also mentioned as a 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。］ The structural unit (a4) also includes a structural unit represented by the formula (a4-4).

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

^Examples of the saturated hydrocarbon group of R ^f22 include the same saturated hydrocarbon group represented by R a42. R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, and an alkyl group having 1 to 10 carbon atoms having a fluorine atom is more preferable. Preferably, an alkyl group having 1 to 6 carbon atoms having a fluorine atom is more preferable.

In the formula (a4-4), as A ^f21 , − (CH ₂ ) _j1 − is preferable, an ethylene group or a methylene group is more preferable, and a methylene group is further preferable.

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, the methyl group corresponding to ^{R f21 in the structural unit (a4-4) is hydrogen.} Examples include structural units that have been replaced by atoms.

When the resin (A) has a structural unit (a4), the content thereof is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and 3) with respect to all the structural units of the resin (A). 10 mol% is more preferable.

［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-eliminating hydrocarbon group contained in the structural unit (a5) include a group having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) is preferably a group having an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1).

[In equation (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 the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. ..
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. .. ]

The alicyclic hydrocarbon group in R ⁵² may be either a monocyclic or polycyclic group. 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.
The aliphatic hydrocarbon group having 1 to 8 carbon atoms includes, for example, 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, a hexyl group, an octyl group and 2 -Alkyl groups such as ethylhexyl groups can be 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 in L ⁵⁵ include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent chain saturated hydrocarbon group is preferable. ..
Examples of the divalent chain saturated hydrocarbon group include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanjiyl group and a pentandiyl group.
The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include a cycloalkanediyl group such as a cyclopentanediyl group and a cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantandiyl group and a norbornanediyl group.

式（Ｌ１−１）中、
Ｘ^x1は、＊−Ｏ−ＣＯ−又は＊−ＣＯ−Ｏ−を表す（＊はＬ^x1との結合手を表す。）。
Ｌ^x1は、炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x2は、単結合又は炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x1及びＬ^x2の合計炭素数は、１６以下である。
式（Ｌ１−２）中、
Ｌ^x3は、炭素数１〜１７の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x4は、単結合又は炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x3及びＬ^x4の合計炭素数は、１７以下である。
式（Ｌ１−３）中、
Ｌ^x5は、炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x6及びＬ^x7は、それぞれ独立に、単結合又は炭素数１〜１４の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x5、Ｌ^x6及びＬ^x7の合計炭素数は、１５以下である。
式（Ｌ１−４）中、
Ｌ^x8及びＬ^x9は、単結合又は炭素数１〜１２の２価の脂肪族飽和炭化水素基を表す。
Ｗ^x1は、炭素数３〜１５の２価の脂環式飽和炭化水素基を表す。
ただし、Ｌ^x8、Ｌ^x9及びＷ^x1の合計炭素数は、１５以下である。 _{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- are represented by the formulas (L1-1) to (L1-4). The groups represented are mentioned. In the following formula, * and ** represent the bond, and * represents the bond with the oxygen atom.

In formula (L1-1),
X ^x1 represents * -O-CO- or * -CO-O- (* represents a bond with ^{L x1).}
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total number of carbon atoms 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 number of carbon atoms 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 number of carbon atoms 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 ^{x 1} represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total number of carbon atoms of ^{L x8} , L ^x9 and W ^{x1 is 15 or less.}

L ^{x 1} is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and 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, and more preferably a single bond.
L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and 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, and 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, and 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, and more preferably a single bond or a methylene group.
W ^{x 1} is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantandiyl group.

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

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

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

Examples of the group represented by the formula (L1-4) include the divalent groups shown below.

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

Examples of the structural unit (a5-1) include the structural unit shown below and the structural unit in which the ^{methyl group corresponding to R 51} in the structural unit (a5-1) in the following structural unit 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 a structural unit (a5), the content thereof is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and 3) with respect to all the structural units of the resin (A). ~ 15 mol% is more preferred.

<Structural unit (II)>
The resin (A) may further contain a structural unit (hereinafter, may be referred to as “structural unit (II)”) that decomposes by exposure to generate an acid. Specific examples of the structural unit (II) include the structural units described in JP-A-2016-79235, and the structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or sulfonio in the side chain. It is preferably a structural unit having a group and an organic anion.

［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 a carboxylate group in the side chain is preferably a structural unit represented by the formula (II-2-A').

[In formula (II-2-A'),
X ^III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH _2- contained in the saturated hydrocarbon group may be replaced with -O-, -S- or -CO-. Often, 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 the hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
RA ⁻ represents a sulfonate group or a carboxylate group.
R ^III3 represents an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or 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, the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 The same can be mentioned.
The ^{alkanediyl group having 1 to 8 carbon atoms represented by A x1} includes 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.
The perfluoroalkyl group carbon atoms which may be have 1-6 substituents in A ^X1, trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, a perfluoro sec- butyl group, perfluoro tert -Butyl group, perfluoropentyl group, perfluorohexyl group and the like can be mentioned.
Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X ^III3 include a linear or branched alkanediyl group and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. And 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, Nonan-1,9-Diyl group, Decane-1,10-Diyl group, Undecane-1,11-Diyl group , Dodecane-1,12-diyl group and other linear alkanediyl groups; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group , Pentan-1,4-diyl group, 2-methylbutane-1,4-diyl group and other branched alkanediyl groups; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 , 4-Diyl group, cycloalkanediyl group such as cyclooctane-1,5-diyl group; norbornan-1,4-diyl group, norbornan-2,5-diyl group, adamantan-1,5-diyl group, adamantan Examples thereof include a divalent polycyclic alicyclic saturated hydrocarbon group such as −2,6-diyl group.
_{When -CH 2-} contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO-, for example, a divalent group represented by the formulas (X1) to (X53) is used. Can be mentioned. _{However, the number of carbon atoms before -CH 2-} contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is 17 or less, respectively. In the following formula, * and ** represent the binding site, and * represents the binding hand with ^{A x1.}

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

^{Examples of ZA +} in the formula (II-2-A') include those similar to the ^{cation Z1 + in the} salt represented by the formula (B1).

［式（ＩＩ−２−Ａ）中、
Ｒ^ＩＩＩ３、Ｘ^ＩＩＩ３及びＺＡ^＋は、上記と同じ意味を表す。
ｚ２Ａは、０〜６のいずれかの整数を表す。
Ｒ^ＩＩＩ２及びＲ^ＩＩＩ４は、それぞれ独立して、水素原子、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表し、ｚ２Ａ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。］
Ｒ^ＩＩＩ２、Ｒ^ＩＩＩ４、Ｑ^ａ及びＱ^ｂで表される炭素数１〜６のペルフルオロアルキル基としては、前述のＱ^ｂ１で表される炭素数１〜６のペルフルオロアルキル基と同じものが挙げられる。 The structural unit represented by the formula (II-2-A') is preferably the structural unit represented by the formula (II-2-A).

[In formula (II-2-A),
R ^III3 , X ^III3 and ZA ⁺ have the same meanings as above.
z2A represents any integer from 0 to 6.
R ^III2 and R ^III4 independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms, and when z2A is 2 or more, a plurality of R ^III2 and R ^III4 are identical to each other. It may be different or it may be different.
Q ^a and Q ^b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. ]
^Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by R III2, R ^III4 , Q ^a and Q ^b include the same perfluoroalkyl group having 1 to 6 carbon atoms represented by ^{Q b1 described above.} ..

［式（ＩＩ−２−Ａ−１）中、
Ｒ^ＩＩＩ２、Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ４、Ｑ^a、Ｑ^b及びＺＡ^＋は、上記と同じ意味を表す。
Ｒ^ＩＩＩ５は、炭素数１〜１２の飽和炭化水素基を表す。
ｚ２Ａ１は、０〜６のいずれかの整数を表す。
Ｘ^Ｉ2は、炭素数１〜１１の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−Ｓ−又は−ＣＯ−に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、ハロゲン原子又はヒドロキシ基で置換されていてもよい。］
Ｒ^ＩＩＩ５で表される炭素数１〜１２の飽和炭化水素基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基及びドデシル基等の直鎖又は分岐のアルキル基が挙げられる。
Ｘ^Ｉ２で表される２価の飽和炭化水素基としては、Ｘ^ＩＩＩ３で表される２価の飽和炭化水素基と同様のものが挙げられる。 The structural unit represented by the formula (II-2-A) is preferably the structural unit represented by the formula (II-2-A-1).

[In formula (II-2-A-1),
^{R III2, R III3, R III4} , Q a, Q b and ZA ⁺ are the same as defined above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
z2A1 represents any integer from 0 to 6.
X ^I2 represents a divalent saturated hydrocarbon group of 1 to 11 carbon atoms, -CH ₂ contained in the saturated hydrocarbon group - is -O -, - it is replaced in S- or -CO- Often, 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 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 thereof include a linear or branched alkyl group such as a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group and a 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ｎＡ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), the structural unit represented by the formula (II-2-A-2) is more preferable.

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

As the structural unit represented by the formula (II-2-A'), for example, the following structural unit, the ^{group corresponding to the methyl group of R III3} , is a hydrogen atom, a halogen atom (for example, a fluorine atom) or a halogen atom. Examples thereof include structural units replaced with alkyl groups having 1 to 6 carbon atoms (for example, trifluoromethyl groups, etc.) and structural units described in WO 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 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 an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or 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 is 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 It may be replaced by -O-, -S- or -CO-. Specifically, the same divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by ^{X III3 can be mentioned.}

As the structural unit containing a cation in the formula (II-1-1), the structural unit represented by the following and the ^{group corresponding to the methyl group of R II4} were replaced with hydrogen atom, fluorine atom, trifluoromethyl and the like. Structural units and the like can be mentioned.

Examples of the organic anion represented by A ⁻ include a sulfonic acid anion, a sulfonylimide anion, a sulfonylmethide anion, and a carboxylic acid anion. The ^{organic anion represented by A −} is preferably a sulfonic acid anion, and the sulfonic acid anion is more preferably an anion contained in the salt represented by the above formula (B1).

Examples of the sulfonylimide anion represented by A ^{− include the following.}

Examples of the sulfonylmethide anion include the following.

Examples of the carboxylic acid anion include the following.

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

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 all the structural units of the resin (A), and more. It is preferably 2 to 15 mol%, more preferably 3 to 10 mol%.

The resin (A) may have a structural unit other than the above-mentioned 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 a structural unit (a1) and a structural unit (s), that is, a copolymer of a monomer (a1) and a monomer (s).
The structural unit (a1) is preferably a group consisting of a structural unit (a1-0), a structural unit (a1-1) and a structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group). At least one selected from, more preferably at least two, and even more preferably at least two selected from the group consisting of structural units (a1-1) and structural units (a1-2).
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 (a2-1) or a structural unit (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). At least one of the choices.
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, a radical polymerization method) using a monomer that derives these structural units. be able to. The content of each structural unit of the resin (A) can be adjusted by adjusting the amount of the monomer used for the polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, still more preferable. Is 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)>
The resist composition of the present invention may be used in combination with a resin other than the resin (A).
Examples of the resin other than the resin (A) include a resin containing a structural unit (a4) or a structural unit (a5) (hereinafter, may be referred to as a resin (X)).
As the resin (X), a resin containing the structural unit (a4) is particularly preferable.
In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, based on the total of all the structural units of the resin (X). , 45 mol% or more is more preferable.
Examples of the structural unit that the resin (X) may further include include a structural unit (a1), a structural unit (a2), a structural unit (a3), and a structural unit derived from other known monomers. Above all, the resin (X) is preferably a resin composed of only the structural unit (a4) and / or the 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, a radical polymerization method) using a monomer for inducing these structural units. can do. The content of each structural unit of the resin (X) can be adjusted by adjusting the amount of the monomer used for the polymerization.
The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of the resin (X) is the same as that of the resin (A).

When the resist composition of the present invention contains the resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass with respect to 100 parts by mass of the resin (A). It is more preferably 1 to 40 parts by mass, further preferably 1 to 30 parts by mass, and particularly preferably 1 to 8 parts by mass.

The content of the resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less, and more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. When a resin other than the resin (A) is contained, the total content of the resin (A) and the resin other than the resin (A) is 80% by mass or more and 99% by mass with respect to the solid content of the resist composition. It is preferably 90% by mass or more and 99% by mass or less. In the present specification, the "solid content of the resist composition" means the total amount of the components excluding the solvent (E) described later from the total amount of the resist composition. The solid content of the resist composition and the content of the resin relative to the solid content can be measured by a known analytical means such as liquid chromatography or gas chromatography.

<Solvent (E)>
The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, and more preferably 94% by mass or more and 99% by mass or less. % Or less. The content of the solvent (E) can be measured by a known analytical means such as liquid chromatography or gas chromatography.

Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate. Esters; ketones such as acetone, methylisobutylketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. One type of solvent (E) may be used alone, or two or more types 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 weaker acidity than the acid generated from the acid generator (B). When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15% by mass based on the solid content of the resist composition, and 0. It is more preferably about 01 to 10% by mass, further preferably about 0.1 to 5% by mass, and even more preferably about 0.1 to 3% by mass.
Examples of the basic nitrogen-containing organic compound include amine and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

Examples of amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-,3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine, Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, trypentylamine, trihexylamine, tri Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, Ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, tri Isopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3 , 3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4-di) Pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethane, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ) Ethan, di (2-pyridyl) ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicorylamine, bipyridine and the like. Diisopropylaniline is preferable, and 2,6-diisopropylaniline is more preferable.

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

The acidity of a salt that produces an acid that is weaker than the acid generated by the acid generator (B) is indicated by the acid dissociation constant (pKa). The salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) is usually a salt having an acid dissociation constant of -3 <pKa, preferably -1 <. It is a salt of pKa <7, more preferably a salt of 0 <pKa <5.
Examples of the salt that generates an acid having a weaker 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, it may be referred to as "weak acid intramolecular salt (D)"), and JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502. Examples thereof include salts described in JP-A-2011-191745. A salt that generates a carboxylic acid having a weaker acidity than the acid generated from the acid generator (B) (a salt having a carboxylic acid anion) is preferable, and a weak acid intramolecular salt (D) is more preferable.

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

<Other ingredients>
The resist composition of the present invention may contain components other than the above-mentioned components (hereinafter, may be referred to as "other components (F)"), if necessary. The other component (F) is not particularly limited, and additives known in the resist field, for example, 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), a resin (A) and an acid generator (B), and if necessary, a resin other than the resin (A) used, a solvent (E), and a quencher ( It can be prepared by mixing C) and the other component (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can be selected from 10 to 40 ° C., depending on the type of resin or the like and the solubility of the resin or the like in the solvent (E). The 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 or the like 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.

<Manufacturing method of resist pattern>
The method for producing a resist pattern of the present invention is
(1) A step of applying the resist composition of the present invention on a substrate,
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
It includes (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 device such as a spin coater. Examples of the substrate include an inorganic substrate such as a silicon wafer. The substrate may be washed before the resist composition is applied, 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 prebaking), or by using a decompression device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. The pressure at the time of vacuum drying is preferably about 1~1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed to an exposure machine. The exposure machine may be an immersion exposure machine. The exposure light source includes a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm) that emits laser light in the ultraviolet region, and a solid-state laser light source (YAG or semiconductor laser). Etc.), and various ones such as those that radiate high-frequency laser light in the far-ultraviolet region or vacuum ultraviolet region by wavelength conversion, those that irradiate electron beams, super-ultraviolet light (EUV), etc. are used. Can be done. In addition, in this specification, irradiating these radiations may be generically referred to as "exposure". At the time of exposure, the exposure is usually performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, the exposure may be performed by drawing directly without using a mask.

The exposed composition layer is heat treated (so-called post-exposure bake) to promote the deprotection reaction at the acid-labile group. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

The composition layer after heating is usually developed using a developing solution using a developing device. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. The developing temperature is preferably, for example, 5 to 60 ° C., and the developing time is preferably, for example, 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any alkaline aqueous solution used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly known as choline) can be mentioned. The alkaline developer may contain a surfactant.
After development, it is preferable to wash the resist pattern with ultrapure water and then remove the substrate and water remaining on the pattern.

When a negative resist pattern is produced from the resist composition of the present invention, a developer containing an organic solvent (hereinafter, may be referred to as "organic developer") is used as the developer.
Examples of the organic solvent contained in the organic developing solution include a ketone solvent such as 2-hexanone and 2-heptanone; a glycol ether ester solvent such as propylene glycol monomethyl ether acetate; an ester solvent such as butyl acetate; and a glycol such as propylene glycol monomethyl ether. Examples include ether solvents; amide solvents such as N and N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and further preferably substantially only the organic solvent.
Among them, as the organic developer, a developer containing butyl acetate and / or 2-heptanone is preferable. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially butyl acetate and / or 2 -It is even more preferable that it is only heptanone.
The organic developer may contain a surfactant. Further, the organic developer may contain a small amount of water.
At the time of development, the development may be stopped by substituting with a solvent of a type different from that of 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 cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the pattern.

<Use>
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 electrons. It is suitable as a resist composition for linear (EB) exposure or a resist composition for EUV exposure, and is useful for fine processing of semiconductors.

The present invention will be described in more detail with reference to examples. In the examples, "%" and "part" representing the content or the 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)
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)
The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC / MSD type). 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１０部及びジメチルホルムアミド５０部を混合し、２３℃で３０分間攪拌した後、炭酸カリウム１．６０部及びヨウ化カリウム０．４８部を添加し、７５℃まで昇温した。得られた混合物に、式（Ｉ−１−ｂ）で表される化合物１１．２７部を添加し、７５℃で５時間撹拌した後、２３℃まで冷却した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水溶液４５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部を添加し、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−１−ｃ）で表される化合物１３．９４部を得た。

式（Ｉ−１−ｃ）で表される塩３．０４部、式（Ｉ−２−ｄ）で表される塩３．０６部、クロロホルム３０部及び酢酸エチル１５部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮残渣に、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、ろ過することにより、式（Ｉ−２）で表される塩４．１５部を得た。 Example 1: Synthesis of salt represented by formula (I-2)

10 parts of the salt represented by the formula (I-1-a) and 50 parts of dimethylformamide are mixed, stirred at 23 ° C. for 30 minutes, and then 1.60 parts of potassium carbonate and 0.48 parts of potassium iodide are added. , The temperature was raised to 75 ° C. 11.27 parts of the compound represented by the formula (I-1-b) was added to the obtained mixture, and the mixture was stirred at 75 ° C. for 5 hours and then cooled to 23 ° C. To the obtained mixture, 100 parts of chloroform and 45 parts of a 5% aqueous oxalic acid solution were added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. By concentrating the obtained organic layer, 13.94 parts of the compound represented by the formula (I-1-c) was obtained.

3.04 parts of the salt represented by the formula (I-1-c), 3.06 parts of the salt represented by the formula (I-2-d), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and 23 ° C. Was stirred for 2 hours. To the obtained mixture, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. 3. The obtained organic layer is concentrated, 30 parts of tert-butyl methyl ether is added to the concentrated residue, the mixture is stirred at 23 ° C. for 30 minutes, and then filtered to obtain a salt represented by the formula (I-2). I got 15 copies.

MASS (ESI (+) Spectrum): M ⁺ 485.2
MASS (ESI (-) Spectrum): M ^- 517.1

式（Ｉ−１−ｃ）で表される塩３．０４部、式（Ｉ−１−ｄ）で表される塩２．９９部、クロロホルム３０部及び酢酸エチル１５部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮残渣に、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、ろ過することにより、式（Ｉ−１）で表される塩４．１５部を得た。 Example 2: Synthesis of salt represented by formula (I-1)

3.04 parts of the salt represented by the formula (I-1-c), 2.99 parts of the salt represented by the formula (I-1-d), 30 parts of chloroform and 15 parts of ethyl acetate are mixed and 23 ° C. Was stirred for 2 hours. To the obtained mixture, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. 3. The obtained organic layer is concentrated, 30 parts of tert-butyl methyl ether is added to the concentrated residue, the mixture is stirred at 23 ° C. for 30 minutes, and then filtered to obtain a salt represented by the formula (I-1). I got 15 copies.

MASS (ESI (+) Spectrum): M ⁺ 485.2
MASS (ESI (-) Spectrum): M ^- 503.1

式（Ｉ−２１−ａ）で表される塩１０．６５部及びジメチルホルムアミド５０部を混合し、２３℃で３０分間攪拌した後、炭酸カリウム１．６０部及びヨウ化カリウム０．４８部を添加し、７５℃まで昇温した。得られた混合物に、式（Ｉ−１−ｂ）で表される化合物１１．２７部を添加し、７５℃で５時間撹拌した後、２３℃まで冷却した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水溶液４５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部を添加し、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−２１−ｃ）で表される化合物１１．８９部を得た。

式（Ｉ−２１−ｃ）で表される塩３．１７部、式（Ｉ−１−ｄ）で表される塩２．９９部、クロロホルム３０部及び酢酸エチル１５部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮残渣に、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、ろ過することにより、式（Ｉ−２１）で表される塩４．０１部を得た。 Example 3: Synthesis of salt represented by formula (I-21)

10.65 parts of the salt represented by the formula (I-21-a) and 50 parts of dimethylformamide are mixed, and after stirring at 23 ° C. for 30 minutes, 1.60 parts of potassium carbonate and 0.48 parts of potassium iodide are added. It was added and the temperature was raised to 75 ° C. 11.27 parts of the compound represented by the formula (I-1-b) was added to the obtained mixture, and the mixture was stirred at 75 ° C. for 5 hours and then cooled to 23 ° C. To the obtained mixture, 100 parts of chloroform and 45 parts of a 5% aqueous oxalic acid solution were added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. By concentrating the obtained organic layer, 11.89 parts of the compound represented by the formula (I-21-c) was obtained.

3.17 parts of the salt represented by the formula (I-21-c), 2.99 parts of the salt represented by the formula (I-1-d), 30 parts of chloroform and 15 parts of ethyl acetate are mixed and 23 ° C. Was stirred for 2 hours. To the obtained mixture, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. The obtained organic layer is concentrated, 30 parts of tert-butyl methyl ether is added to the concentrated residue, the mixture is stirred at 23 ° C. for 30 minutes, and then filtered to obtain a salt represented by the formula (I-21). I got 01 copies.

MASS (ESI (+) Spectrum): M ⁺ 513.3
MASS (ESI (-) Spectrum): M ^- 503.1

式（Ｉ−４２−ａ）で表される塩１０部及びジメチルホルムアミド５０部を混合し、２３℃で３０分間攪拌した後、炭酸カリウム１．４８部及びヨウ化カリウム０．４４部を添加し、７５℃まで昇温した。得られた混合物に、式（Ｉ−１−ｂ）で表される化合物１０．４０部を添加し、７５℃で５時間撹拌した後、２３℃まで冷却した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水溶液４５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部を添加し、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−４２−ｃ）で表される化合物１２．８９部を得た。

式（Ｉ−４２−ｃ）で表される塩３．２１部、式（Ｉ−２−ｄ）で表される塩３．０６部、クロロホルム３０部及び酢酸エチル１５部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮残渣に、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、ろ過することにより、式（Ｉ−４２）で表される塩４．５６部を得た。 Example 4: Synthesis of salt represented by formula (I-42)

10 parts of the salt represented by the formula (I-42-a) and 50 parts of dimethylformamide were mixed, stirred at 23 ° C. for 30 minutes, and then 1.48 parts of potassium carbonate and 0.44 parts of potassium iodide were added. , The temperature was raised to 75 ° C. To the obtained mixture, 10.40 parts of the compound represented by the formula (I-1-b) was added, the mixture was stirred at 75 ° C. for 5 hours, and then cooled to 23 ° C. To the obtained mixture, 100 parts of chloroform and 45 parts of a 5% aqueous oxalic acid solution were added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. By concentrating the obtained organic layer, 12.89 parts of the compound represented by the formula (I-42-c) was obtained.

3.21 parts of the salt represented by the formula (I-42-c), 3.06 parts of the salt represented by the formula (I-2-d), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and 23 ° C. Was stirred for 2 hours. To the obtained mixture, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. 3. The obtained organic layer is concentrated, 30 parts of tert-butyl methyl ether is added to the concentrated residue, the mixture is stirred at 23 ° C. for 30 minutes, and then filtered to obtain a salt represented by the formula (I-42). I got 56 copies.

MASS (ESI (+) Spectrum): M ⁺ 521.2
MASS (ESI (-) Spectrum): M ^- 517.1

式（Ｉ−６２−ａ）で表される塩１０部及びジメチルホルムアミド５０部を混合し、２３℃で３０分間攪拌した後、炭酸カリウム１．２２部及びヨウ化カリウム０．３６部を添加し、７５℃まで昇温した。得られた混合物に、式（Ｉ−１−ｂ）で表される化合物８．５６部を添加し、７５℃で５時間撹拌した後、２３℃まで冷却した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水溶液４５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部を添加し、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−６２−ｃ）で表される化合物１１．７２部を得た。

式（Ｉ−６２−ｃ）で表される塩３．６９部、式（Ｉ−２−ｄ）で表される塩３．０６部、クロロホルム３０部及び酢酸エチル１５部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮残渣に、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、ろ過することにより、式（Ｉ−６２）で表される塩４．８８部を得た。 Example 5: Synthesis of salt represented by formula (I-62)

10 parts of the salt represented by the formula (I-62-a) and 50 parts of dimethylformamide were mixed, stirred at 23 ° C. for 30 minutes, and then 1.22 parts of potassium carbonate and 0.36 parts of potassium iodide were added. , The temperature was raised to 75 ° C. To the obtained mixture, 8.56 parts of the compound represented by the formula (I-1-b) was added, the mixture was stirred at 75 ° C. for 5 hours, and then cooled to 23 ° C. To the obtained mixture, 100 parts of chloroform and 45 parts of a 5% aqueous oxalic acid solution were added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. By concentrating the obtained organic layer, 11.72 parts of the compound represented by the formula (I-62-c) was obtained.

3.69 parts of the salt represented by the formula (I-62-c), 3.06 parts of the salt represented by the formula (I-2-d), 30 parts of chloroform and 15 parts of ethyl acetate are mixed and 23 ° C. Was stirred for 2 hours. To the obtained mixture, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. 3. The obtained organic layer is concentrated, 30 parts of tert-butyl methyl ether is added to the concentrated residue, the mixture is stirred at 23 ° C. for 30 minutes, and then filtered to obtain a salt represented by the formula (I-62). 88 copies were obtained.

MASS (ESI (+) Spectrum): M ⁺ 621.2
MASS (ESI (-) Spectrum): M ^- 517.1

式（Ｉ−３０２−ａ）で表される塩１０部及びジメチルホルムアミド５０部を混合し、２３℃で３０分間攪拌した後、炭酸カリウム１．０１部及びヨウ化カリウム０．３０部を添加し、７５℃まで昇温した。得られた混合物に、式（Ｉ−１−ｂ）で表される化合物７．１０部を添加し、７５℃で５時間撹拌した後、２３℃まで冷却した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水溶液４５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部を添加し、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−３０２−ｃ）で表される化合物１０．４８部を得た。

式（Ｉ−３０２−ｃ）で表される塩４．２４部、式（Ｉ−２−ｄ）で表される塩３．０６部、クロロホルム３０部及び酢酸エチル１５部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮残渣に、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、ろ過することにより、式（Ｉ−３０２）で表される塩４．８９部を得た。 Example 6: Synthesis of salt represented by formula (I-302)

10 parts of the salt represented by the formula (I-302-a) and 50 parts of dimethylformamide are mixed, stirred at 23 ° C. for 30 minutes, and then 1.01 part of potassium carbonate and 0.30 part of potassium iodide are added. , The temperature was raised to 75 ° C. To the obtained mixture, 7.10 parts of the compound represented by the formula (I-1-b) was added, and the mixture was stirred at 75 ° C. for 5 hours and then cooled to 23 ° C. To the obtained mixture, 100 parts of chloroform and 45 parts of a 5% aqueous oxalic acid solution were added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. By concentrating the obtained organic layer, 10.48 parts of the compound represented by the formula (I-302-c) was obtained.

4.24 parts of the salt represented by the formula (I-302-c), 3.06 parts of the salt represented by the formula (I-2-d), 30 parts of chloroform and 15 parts of ethyl acetate are mixed and 23 ° C. Was stirred for 2 hours. To the obtained mixture, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. 3. The obtained organic layer is concentrated, 30 parts of tert-butyl methyl ether is added to the concentrated residue, the mixture is stirred at 23 ° C. for 30 minutes, and then filtered to obtain a salt represented by the formula (I-302). I got 89 copies.

MASS (ESI (+) Spectrum): M ⁺ 737.0
MASS (ESI (-) Spectrum): M ^- 517.1

式（Ｉ−３６２−ａ）で表される塩５．１９部及びジメチルホルムアミド５０部を混合し、２３℃で３０分間攪拌した後、炭酸カリウム１．６０部及びヨウ化カリウム０．４８部を添加し、７５℃まで昇温した。得られた混合物に、式（Ｉ−１−ｂ）で表される化合物１１．２７部を添加し、７５℃で５時間撹拌した後、２３℃まで冷却した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水溶液４５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部を添加し、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−３６２−ｃ）で表される化合物８．２４部を得た。

式（Ｉ−３６２−ｃ）で表される塩４．１０部、式（Ｉ−２−ｄ）で表される塩３．０６部、クロロホルム３０部及び酢酸エチル１５部を混合し、２３℃で２時間攪拌した。得られた混合物に、イオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮し、濃縮残渣に、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、ろ過することにより、式（Ｉ−３６２）で表される塩４．８９部を得た。 Example 7: Synthesis of salt represented by formula (I-362)

5.19 parts of the salt represented by the formula (I-362-a) and 50 parts of dimethylformamide are mixed, and after stirring at 23 ° C. for 30 minutes, 1.60 parts of potassium carbonate and 0.48 parts of potassium iodide are added. It was added and the temperature was raised to 75 ° C. 11.27 parts of the compound represented by the formula (I-1-b) was added to the obtained mixture, and the mixture was stirred at 75 ° C. for 5 hours and then cooled to 23 ° C. To the obtained mixture, 100 parts of chloroform and 45 parts of a 5% aqueous oxalic acid solution were added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. By concentrating the obtained organic layer, 8.24 parts of the compound represented by the formula (I-362-c) was obtained.

4.10 parts of the salt represented by the formula (I-362-c), 3.06 parts of the salt represented by the formula (I-2-d), 30 parts of chloroform and 15 parts of ethyl acetate are mixed and 23 ° C. Was stirred for 2 hours. To the obtained mixture, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 30 minutes and then separated to remove the organic layer. This washing operation was repeated 5 times. 3. The obtained organic layer is concentrated, 30 parts of tert-butyl methyl ether is added to the concentrated residue, the mixture is stirred at 23 ° C. for 30 minutes, and then filtered to obtain a salt represented by the formula (I-362). I got 89 copies.

MASS (ESI (+) Spectrum): M ⁺ 707.3
MASS (ESI (-) Spectrum): M ^- 517.1

Synthesis of Resin The compounds (monomers) used for the synthesis of the resin (A) are shown below. Hereinafter, these compounds are referred to as "monomers (a1-1-3)" and the like according to their formula numbers.

Synthesis Example 1 [Synthesis of resin A1]
As the monomer, a monomer (a1-4-2), a monomer (a1-1-3) and a monomer (a1-2-6) are used, and their molar ratio [monomer (a1-4-2): monomer (a1-1-1). -3): Monomer (a1-2-6)] was mixed in a ratio of 38:24:38, and the monomer mixture was added 1.5 times by mass with respect to the total mass of all the monomers. Methyl isobutyl ketone was mixed. Azobisisobutyronitrile as an initiator was added to the obtained mixture so as to be 7 mol% based on the total number of moles of all the monomers, and this was heated at 85 ° C. for about 5 hours to carry out polymerization. rice field. Then, a p-toluenesulfonic acid aqueous solution (2.5% by mass), which was 2.0 times by mass with respect to the total mass of the total amount of monomers, was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The resulting organic layer, to precipitate a resin poured into a large amount of n- heptane by filtration and recovered, yield 78 resin A1 (copolymer) is the weight average molecular weight of about 5.3 × 10 ³ Obtained in%. This resin A1 has the following structural units.

Synthesis Example 2 [Synthesis of resin A2]
As the monomer, a monomer (a1-4-2) and a monomer (a1-2-6) are used, and the molar ratio [monomer (a1-4-2): monomer (a1-2-6)] is 38:62. Methyl isobutyl ketone was further mixed with this monomer mixture in an amount of 1.5% by mass based on the total mass of all the monomers. Azobisisobutyronitrile as an initiator was added to the obtained mixture so as to be 7 mol% based on the total number of moles of all the monomers, and this was heated at 85 ° C. for about 5 hours to carry out polymerization. rice field. Then, a p-toluenesulfonic acid aqueous solution (2.5% by mass), which was 2.0 times by mass with respect to the total mass of the total amount of monomers, was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The resulting organic layer, to precipitate a resin poured into a large amount of n- heptane by filtration and recovered, the resin weight average molecular weight of about 5.4 × 10 ³ A2 (copolymer) to yield 89 Obtained in%. This resin A2 has the following structural units.

<Preparation of resist composition>
As shown in Table 2, each of the following components was mixed, and the obtained mixture was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

ＩＸ−２：

ＩＸ−３：

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

＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ４００部
プロピレングリコールモノメチルエーテル １００部
γ−ブチロラクトン ５部 <Resin>
A1, A2: Resin A1, Resin A2
<Salt (I)>
I-1: Salt represented by the formula (I-1) I-2: Salt represented by the formula (I-2) I-21: Salt represented by the formula (I-21) I-42: Formula Salt represented by (I-42) I-62: Salt represented by formula (I-62) I-302: Salt represented by formula (I-302) I-362: Salt represented by formula (I-362) Salt represented by <acid generator>
IX-1:

IX-2:

IX-3:

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

<Solvent>
Propylene Glycol Monomethyl Ether Acetate 400 Parts Propylene Glycol Monomethyl Ether 100 Parts γ-Butyrolactone 5 Parts

(Evaluation of electron beam exposure of resist composition)
A 6 inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 ° C. for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, on a direct hot plate, a composition layer was formed by prebaking at the temperature shown in the “PB” column of Table 2 for 60 seconds. A contact hole pattern (hole pitch 40 nm / hole) is used on the composition layer formed on the wafer by using an electron beam drawing machine [“ELS-F125 125keV” manufactured by Elionix Inc.] and the exposure amount is changed stepwise. Diameter 17 nm) was drawn directly.
After exposure, post-exposure baking is performed on a hot plate at the temperature shown in the “PEB” column of Table 2 for 60 seconds, and further paddle development is performed for 60 seconds with a 2.38 mass% tetramethylammonium hydroxide aqueous solution. , A resist pattern was obtained.

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

<CD uniformity (CDU) evaluation>
In the effective sensitivity, the hole diameter of the pattern formed with the hole diameter of 17 nm was measured 24 times per hole, and the average value was taken as the average hole diameter of one hole. The standard deviation was determined by measuring the average hole diameter of a pattern formed with a hole diameter of 17 nm at 400 points on the same wafer as a population.
The results are shown in Table 3. The numbers in the table indicate the standard deviation (nm).

比較組成物１〜３と比較して、組成物１〜８での標準偏差が小さく、ＣＤ均一性（ＣＤＵ）評価が良好であった。

The standard deviation of the compositions 1 to 8 was smaller than that of the comparative compositions 1 to 3, and the CD uniformity (CDU) evaluation was good.

The resist composition containing the salt of the present invention is suitable for microfabrication of semiconductors and is extremely useful industrially because a resist pattern having good CD uniformity (CDU) can be obtained.

Claims (14)

A salt represented by the formula (I).

[In formula (I),
R ¹ represents ^{−OL 1} −CO—O—R ^5.
L ¹ represents an alkanediyl group having 1 to 6 carbon atoms.
R ⁵ represents an acid unstable group.
R ² , R ³ and R ⁴ independently represent a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms or a hydrocarbon group having 1 to 18 carbon atoms, and are contained in the hydrocarbon group -CH _2. -May be replaced by -O- or -CO-.
m2 represents any integer from 0 to 4, and when m2 is 2 or more, a plurality of R ^2s may be the same or different from each other.
m3 represents an integer of 0 to 5, when m3 is 2 or more, plural R ³ may be the same or different from each other.
m4 represents an integer of 0 to 5, when m4 is 2 or more, plural R ⁴ may be the same or different from each other.
Q ¹ and Q ² independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹¹ and R ¹² independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹¹ and R ¹² may be the same or different from each other.
X ¹ is * -CO-O-, * -O-CO-, * -O-CO-O- or * -O- (where * is C (R ¹¹ ) (R ¹² ) or C (Q). ¹ ) Represents the binding site with (Q ^2).).
A ¹ represents a group formed by combining a saturated cyclic hydrocarbon group and an alkanediyl group, and the total carbon number of the saturated cyclic hydrocarbon group and the alkanediyl group is 4 to 36. Both the saturated cyclic hydrocarbon group and the alkanediyl group may have a substituent, and −CH ₂ − contained in the saturated cyclic hydrocarbon group and the alkanediyl group is −O−, −S. -, - CO- or -SO ₂ - may be replaced to.
R ¹³ represents a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and −CH ₂ − contained in the cyclic hydrocarbon group is −O−, −S−, −CO. -Or -SO _2- may be replaced. ] The salt according to claim 1, wherein R ⁵ is a group represented by the formula (1a) or a group represented by the formula (2a).

[In the formula (1a), ^Raa1 , ^Raa2 and ^Raa3 independently have an alkyl group having 1 to 8 carbon atoms which may have a substituent and a carbon number which may have a substituent. An alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have an alkenyl group of 2 to 8 and a substituent or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. Represented or ^Raa1 and ^Raa2 bond with each other to form an alicyclic hydrocarbon group with 3 to 20 carbon atoms with the carbon atoms to which they are attached.
* Represents a bond. ]

Wherein (2a), R ^{aa1 'and} R ^aa2' each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^{aa3 'is} a hydrocarbon group having 1 to 20 carbon atoms represents or R ^{aa2 'and} R ^aa3' is bonded to -C-X a to which they are attached to one another ^- to form together with heterocyclic group having 3 to 20 carbon atoms, the hydrocarbon group and heterocyclic group The included −CH ₂₋ may be replaced by −O− or −S−.
X ^a represents an oxygen atom or a sulfur atom.
* Represents a bond. ] A ¹ is * -L ^2- CO-O- (L ² is a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms or a cyclic hydrocarbon group having 3 to 18 carbon atoms and an alkanediyl group having 1 to 4 carbon atoms. represents a group which combines bets, -CH ₂ contained in the saturated cyclic hydrocarbon group - is, -O -, - S -, - CO- or -SO ₂ - may be replaced in, the alkanediyl group _{-CH 2-} contained in may be replaced with -O- or -CO-. * Represents a bond with ^{X 1 ) or * -L 21-} W ^1- L ^22- CO- O-L 23 ^{- (W 1} represents a divalent saturated cyclic hydrocarbon group, the saturated cyclic hydrocarbon group may have a substituent, -CH ₂ contained in the saturated cyclic hydrocarbon group -May be replaced with -O-, -S-, -CO- or -SO _2-. ^{L 21} , L ²² and L ²³ are independently single-bonded or 1 to 4 carbon alkanes, respectively. represents a diyl group, -CH ₂ contained in the alkanediyl group -. is that may be replaced by -O- or -CO- * is claim 1 represents a bonding site with ^{X 1)} a is. Or the salt according to 2. L ² and ^{W 1} is the following formula ^(L 2 -1), formula ^(L 2 -2), group (* is represented by the formula ^(L 2 -3) or formula ^(L 2 -4), bond The salt according to claim 3.

The salt according to any one of claims 1 to 4, wherein X ^{1 is * -CO-O-.} m3 is an integer of 1 or 2,
m4 is an integer of 0 to 2,
The salt according to any one of claims 1 to 5, wherein any one of R ³ and R ^{4 is a fluorine atom, an iodine atom or trifluoromethyl.} m3 is an integer of 1 or 2,
m4 is an integer of 0 to 2,
One of R ³ and R ⁴ is -OL ^1- CO-O-R ⁵ .
The plurality of R ^5, salts of any one of identical A claim according may be either same or different 1 to 5 with each other. m2 is 1 or 2
At least one of the plurality of ^{R 2 is} -O-L 1 -CO-O- R 5,
The plurality of R ^5, salts of any one of identical A claim according or different from each other 1-7 together. An acid generator containing the salt according to any one of claims 1 to 8. A resist composition containing the acid generator according to claim 9 and a resin having an acid unstable group. 10. The 10. Resist composition.

[In the formula (a1-1) and the formula (a1-2),
^La1 and ^La2 independently represent -O- or * -O- (CH ₂ ) _k1- CO-O-, k1 represents an integer of 1 to 7, and * represents -CO-. Represents a bond with.
R ^a4 and R ^a5 each independently represent an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom.
R ^a6 and R ^a7 independently have an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic group having 6 to 18 carbon atoms. Represents a hydrocarbon group or a group combining these groups.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1'represents an integer of 0 to 3. ] The resist composition according to claim 10 or 11, wherein the resin having an acid unstable group contains a structural unit represented by the formula (a2-A).

[In formula (a2-A),
R ^a50 represents an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, and a carbon number of carbon atoms. It represents an alkylcarbonyl group of 2 to 4, an alkylcarbonyloxy group of 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group.
A ^a50 represents a single bond or ^* −X ^a51 − (A ^a52 −X ^a52 ) _nb −, and * represents a bond with the carbon atom to which ^{−R a50 is bonded.}
A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 independently represent -O-, -CO-O- or -O-CO-, respectively.
nb represents 0 or 1.
mb represents any integer from 0 to 4. When mb is any integer of 2 or more, the plurality of Ra ^51s may be the same or different from each other. ] The resist composition according to any one of claims 10 to 12, further containing a salt that generates an acid having a weaker acidity than the acid generated from the acid generator. (1) A step of applying the resist composition according to any one of claims 10 to 13 onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) 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,
A method for producing a resist pattern including.