JP2016147975A - Resin, resist composition, and production method of resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin to be used for a resist composition from which a resist pattern can be produced with good CD uniformity, and a resist composition.SOLUTION: The resin has a structural unit represented by formula (I) and a structural unit having an acid-labile group. In the formula, Rrepresents a hydrogen atom or a methyl group; Rand Reach independently represent a hydrogen atom, a hydroxy group or a hydrocarbon group having 1 to 12 carbon atoms, in which -CH- included in the hydrocarbon group may be replaced by -O- or -CO-, and Rand Rmay be coupled to form a ring; Arepresents a single bond, a divalent hydrocarbon group having 1 to 12 carbon atoms, or the like; and Lrepresents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms.SELECTED DRAWING: None

Description

  The present invention relates to a resin, a resist composition containing the resin, and a method for producing a resist pattern.

  Patent Document 1 describes a resin composed of the following compound and a structural unit derived from the following compound.

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

WO2014 / 092914 pamphlet JP 2006-257078 A

  In a resist composition using a resin composed of a structural unit derived from the above compound, CD uniformity may not always be satisfied.

The present invention includes the following inventions.
[1] A resin having a structural unit represented by the formula (I) and a structural unit having an acid labile group.

［式（Ｉ）中、
Ｒ^１は、水素原子又はメチル基を表す。
Ｒ^２及びＲ^３は、それぞれ独立に、水素原子、ヒドロキシ基又は炭素数１〜１２の炭化水素基を表し、該炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよく、Ｒ^２及びＲ^３が一緒になって環を形成してもよい。
Ａ^１は、単結合、炭素数１〜１２の２価の炭化水素基又は^＊−Ａ^２−Ｘ^１−（Ａ^３−Ｘ^２）_ａ−（Ａ^４）_ｂ−を表す。＊は酸素原子との結合手を表す。
Ａ^２〜Ａ^４は、それぞれ独立に、炭素数１〜１２の２価の炭化水素基を表す。
Ｘ^１及びＸ^２は、それぞれ独立に、−Ｏ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−又は−Ｏ−ＣＯ−Ｏ−を表す。
ａは、０又は１を表す。
ｂは、０又は１を表す。
Ｌ^１は、単結合又は炭素数１〜１２の２価の炭化水素基を表す。］
〔２〕Ａ^１が、単結合又はメチレン基である〔１〕記載の樹脂。
〔３〕式（Ｉ）で表される構造単位が、式（ＩＡ）で表される構造単位である〔１〕又は〔２〕記載の樹脂。

［式（ＩＡ）中、
Ｒ^１は、水素原子又はメチル基を表す。
Ｗ^１は、炭素数４〜１２の２価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−又は−ＣＯ−で置き換わっていてもよい。
Ａ^１は、単結合、炭素数１〜１２の２価の炭化水素基又は^＊−Ａ^２−Ｘ^１−（Ａ^３−Ｘ^２）_ａ−（Ａ^４）_ｂ−を表す。＊は酸素原子との結合手を表す。
Ａ^２〜Ａ^４は、それぞれ独立に、炭素数１〜１２の２価の炭化水素基を表す。
Ｘ^１及びＸ^２は、それぞれ独立に、−Ｏ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−又は−Ｏ−ＣＯ−Ｏ−を表す。
ａは、０又は１を表す。
ｂは、０又は１を表す。
Ｌ^１は、単結合又は炭素数１〜１２の２価の炭化水素基を表す。］
〔４〕Ｗ^１が、炭素数４〜１２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−の少なくとも一つは、−Ｏ−又は−ＣＯ−で置き換わる〔３〕記載の樹脂。
〔５〕酸不安定基を有する構造単位が、式（ａ１−１）又は式（ａ１−２）で表される構造単位である〔１〕〜〔４〕のいずれか記載の樹脂。

［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の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合せることにより形成される基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ１’は０〜３の整数を表す。］
〔６〕酸不安定基を有する構造単位が、式（ａ１−１）及び式（ａ１−２）で表される構造単位を含む〔１〕〜〔５〕のいずれか記載の樹脂。
〔７〕樹脂が、さらに、ヒドロキシ基を有する構造単位を含む〔１〕〜〔６〕のいずれかに記載の樹脂。
〔８〕ヒドロキシ基を有する構造単位が、式（ａ２−１）で表される構造単位である〔７〕記載の樹脂。

［式（ａ２−１）中、
Ｌ^ａ３は、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ２−ＣＯ−Ｏ−を表し、
ｋ２は１〜７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の整数を表す。］
〔９〕樹脂が、さらに、ラクトン環を有する構造単位を含む〔１〕〜〔８〕のいずれか記載の樹脂。
〔１０〕ラクトン環を有する構造単位が、式（ａ３−１）、式（ａ３−２）、式（ａ３−３）又は式（ａ３−４）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種である〔９〕記載の樹脂。

［式（ａ３−１）中、
Ｌ^ａ４は、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^ａ１８は、水素原子又はメチル基を表す。
Ｒ^ａ２１は炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は０〜５の整数を表す。ｐ１が２以上のとき、複数のＲ^ａ２１は互いに同一であっても異なってもよい。
式（ａ３−２）中、
Ｌ^ａ５は、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^ａ１９は、水素原子又はメチル基を表す。
Ｒ^ａ２２は、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。
ｑ１は、０〜３の整数を表す。ｑ１が２以上のとき、複数のＲ^ａ２２は互いに同一であっても異なってもよい。
式（ａ３−３）中、
Ｌ^ａ６は、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^ａ２０は、水素原子又はメチル基を表す。
Ｒ^ａ２３は、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。
ｒ１は、０〜３の整数を表す。ｒ１が２以上のとき、複数のＲ^ａ２３は互いに同一であっても異なってもよい。
式（ａ３−４）中、
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。
Ｌ^ａ７は、単結合、^＊−Ｌ^ａ８−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−Ｌ^ａ９−ＣＯ−Ｏ−又は^＊−Ｌ^ａ８−Ｏ−ＣＯ−Ｌ^ａ９−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ｌ^ａ８及びＬ^ａ９は、互いに独立に、炭素数１〜６のアルカンジイル基を表す。］
〔１１〕〔１〕〜〔１０〕のいずれか記載の樹脂及び酸発生剤を含有するレジスト組成物。
〔１２〕酸発生剤が、式（Ｂ１）で表される酸発生剤である〔１１〕記載のレジスト組成物。

［式（Ｂ１）中、
Ｑ^１及びＱ^２は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
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炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の１価の脂環式炭化水素基を表し、該アルキル基及び該１価の脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］
〔１３〕樹脂が、さらに、フッ素原子を有する構造単位を含む樹脂を含有する〔１１〕又は〔１２〕記載のレジスト組成物。
〔１４〕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〔１１〕〜〔１３〕のいずれか記載のレジスト組成物。
〔１５〕（１）〔１１〕〜〔１４〕のいずれか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。

[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ² and R ³ each independently represent a hydrogen atom, a hydroxy group or a hydrocarbon group having 1 to 12 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO—. R ² and R ³ may be combined to form a ring.
A ¹ represents a single bond, a divalent hydrocarbon group having 1 to 12 carbon atoms or ^{* -A 2 -X 1 - (A} 3 -X 2) a - (A 4) b - represents a. * Represents a bond with an oxygen atom.
A ^{2 to} A ⁴ each independently represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
X ¹ and X ² each independently represent —O—, —CO—O—, —O—CO— or —O—CO—O—.
a represents 0 or 1.
b represents 0 or 1.
L ¹ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms. ]
[2] The resin according to [1], wherein A ¹ is a single bond or a methylene group.
[3] The resin according to [1] or [2], wherein the structural unit represented by the formula (I) is a structural unit represented by the formula (IA).

[In the formula (IA),
R ¹ represents a hydrogen atom or a methyl group.
W ¹ represents a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, and —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O— or —CO—. Good.
A ¹ represents a single bond, a divalent hydrocarbon group having 1 to 12 carbon atoms or ^{* -A 2 -X 1 - (A} 3 -X 2) a - (A 4) b - represents a. * Represents a bond with an oxygen atom.
A ^{2 to} A ⁴ each independently represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
X ¹ and X ² each independently represent —O—, —CO—O—, —O—CO— or —O—CO—O—.
a represents 0 or 1.
b represents 0 or 1.
L ¹ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms. ]
[4] W ¹ represents an alicyclic hydrocarbon group having 4 to 12 carbon atoms, and at least one of —CH ₂ — contained in the alicyclic hydrocarbon group is —O— or —CO—. Resin according to [3] to be replaced.
[5] The resin according to any one of [1] to [4], wherein the structural unit having an acid labile group is a structural unit represented by Formula (a1-1) or Formula (a1-2).

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]
[6] The resin according to any one of [1] to [5], wherein the structural unit having an acid labile group includes a structural unit represented by formula (a1-1) or formula (a1-2).
[7] The resin according to any one of [1] to [6], wherein the resin further includes a structural unit having a hydroxy group.
[8] The resin according to [7], wherein the structural unit having a hydroxy group is a structural unit represented by the formula (a2-1).

[In the formula (a2-1),
L ^a3 represents —O— or ^* —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10. ]
[9] The resin according to any one of [1] to [8], wherein the resin further contains a structural unit having a lactone ring.
[10] The structural unit having a lactone ring is selected from the group consisting of structural units represented by formula (a3-1), formula (a3-2), formula (a3-3), or formula (a3-4). The resin according to [9], which is at least one kind.

[In the formula (a3-1),
L ^a4 represents a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 may be the same as or different from each other.
In formula (a3-2),
L ^a5 represents a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 may be the same as or different from each other.
In formula (a3-3),
L ^a6 represents a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, the plurality of R ^a23 may be the same as or different from each other.
In formula (a3-4),
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom.
L ^a7 is a single bond, ^* —L ^a8 —O—, ^* —L ^a8 —CO—O—, ^* —L ^a8 —CO—O—L ^a9 —CO—O— or ^* —L ^a8 —O—CO ^-La9- O- is represented.
* Represents a bond with -O-.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms. ]
[11] A resist composition containing the resin according to any one of [1] to [10] and an acid generator.
[12] The resist composition according to [11], wherein the acid generator is an acid generator represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — contained in the group and the monovalent alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]
[13] The resist composition according to [11] or [12], wherein the resin further contains a resin containing a structural unit having a fluorine atom.
[14] The resist composition according to any one of [11] to [13], further including a salt that generates an acid having a lower acidity than an acid generated from an acid generator.
[15] (1) A step of applying the resist composition according to any one of [11] to [14] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.

  By using a resist composition using the resin of the present invention, a resist pattern can be produced with good CD uniformity.

  In the present specification, unless otherwise specified, in the description of the structural formula of a compound, a group that can be either linear or branched, such as “aliphatic hydrocarbon group”, includes both of them, The “type hydrocarbon group” means a group obtained by removing a number of hydrogen atoms corresponding to the valence from the ring of the alicyclic hydrocarbon. The “aromatic hydrocarbon group” also includes a group in which a hydrocarbon group is bonded to an aromatic ring. When stereoisomers exist, all stereoisomers are included.

In the present specification, "(meth) acrylic monomer" means at least one monomer having a _"CH 2 = _CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " structure of To do. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

<Resin>
The resin of the present invention (hereinafter sometimes referred to as “resin (A)”)
A structural unit represented by the formula (I) (hereinafter sometimes referred to as “structural unit (I)”), a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a1)”), including.

［式（Ｉ）中、
Ｒ^１は、水素原子又はメチル基を表す。
Ｒ^２及びＲ^３は、それぞれ独立に、水素原子、ヒドロキシ基又は炭素数１〜１２の炭化水素基を表し、該炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよく、Ｒ^２及びＲ^３が一緒になって環を形成してもよい。
Ａ^１は、単結合、炭素数１〜１２の２価の炭化水素基又は^＊−Ａ^２−Ｘ^１−（Ａ^３−Ｘ^２）_ａ−（Ａ^４）_ｂ−を表す。＊は酸素原子との結合手を表す。
Ａ^２〜Ａ^４は、それぞれ独立に、炭素数１〜１２の２価の炭化水素基を表す。
Ｘ^１及びＸ^２は、それぞれ独立に、−Ｏ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−又は−Ｏ−ＣＯ−Ｏ−を表す。
ａは、０又は１を表す。
ｂは、０又は１を表す。
Ｌ^１は、単結合又は炭素数１〜１２の２価の炭化水素基を表す。］ <Structural unit (I)>
The structural unit (I) has the following structure.

[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ² and R ³ each independently represent a hydrogen atom, a hydroxy group or a hydrocarbon group having 1 to 12 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO—. R ² and R ³ may be combined to form a ring.
A ¹ represents a single bond, a divalent hydrocarbon group having 1 to 12 carbon atoms or ^{* -A 2 -X 1 - (A} 3 -X 2) a - (A 4) b - represents a. * Represents a bond with an oxygen atom.
A ^{2 to} A ⁴ each independently represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
X ¹ and X ² each independently represent —O—, —CO—O—, —O—CO— or —O—CO—O—.
a represents 0 or 1.
b represents 0 or 1.
L ¹ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms. ]

Examples of the divalent hydrocarbon group having 1 to 12 carbon atoms of A ^{1 to} A ⁴ and L ¹ include an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and aromatic carbonization. Examples thereof include a hydrogen group, and two or more of these groups may be combined.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group , Tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group Alkanediyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Group;
And aromatic hydrocarbon groups such as a phenylene group, a tosylene group, a naphthylene group, a biphenylene group, a xylylene group, and an anthracenylene group.

^* -A ² -X ^1- (A ³ -X ² ) _a- (A ⁴ ) _b -is as follows: ^* -A ² -O-, ^* -A ² -CO-O-, ^* -A ² -O —CO—O—, ^* —A ² —O—CO—, ^* —A ² —O—A ⁴ —, ^* —A ² —CO—O—A ⁴ —, ^* —A ² —O—CO—A. ^{4 -, * -A 2 -O-} CO-O-A 4 -, * -A 2 -CO-O-A 3 -CO-O-, * -A 2 -CO-O-A 3 -CO-O ^{-A 4 -, * -A 2 -O} -CO-A 3 -O-, * -A 2 -O-CO-A 3 -O-A 4 -, * -A 2 -O-CO-O-A ^{3 -O-, * -A 2 -O-} CO-O-A 3 -O-A 4 -, * -A 2 -O-A 3 -CO-O-, * -A 2 -O-A 3 - ^{CO-O-A 4 -,} * -A 2 -CO-O-A 3 -O-CO- ^{* -A 2 -CO-O-A} 3 -O-CO-A 4 -, * -A 2 -O-CO-A 3 -O-CO-, * -A 2 -O-CO-A 3 -O —CO—A ⁴ — is preferable, and ^* —A ² —CO—O—A ⁴ — or ^* —A ² —CO—O— is preferable. * Represents a bond with an oxygen atom.

A ^{1 to} A ⁴ are preferably a C 1-6 divalent alkanediyl group or a polycyclic divalent alicyclic saturated hydrocarbon group.
A ¹ is preferably a single bond, a methylene group or ^* —A ² —X ¹ —, and more preferably a single bond or a methylene group.
L ¹ is preferably a single bond, a divalent alkanediyl group having 1 to 6 carbon atoms or a polycyclic divalent alicyclic saturated hydrocarbon group, and is a single bond or a divalent alkane having 1 to 6 carbon atoms. It is more preferably a diyl group, and further preferably a single bond or a methylene group.

Examples of the hydrocarbon group for R ² and R ³ include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by a combination thereof.
As the alkyl group, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group , Nonyl group, decyl group, undecyl group, dodecyl group and the like.
The 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 methylcyclohexyl group. And cycloalkyl groups such as dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.
Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group.
Examples of the group formed by combination include an aralkyl group, such as a benzyl group and a phenethyl group.
Examples of the group in which —CH ₂ — contained in the hydrocarbon group is replaced by —O— or —CO— include a methoxy group, an ethoxy group, a butoxy group, an acetyl group, a methoxycarbonyl group, an acetyloxy group, and a butoxycarbonyloxy group. And benzoyloxy group.

R ² and R ³ preferably form a ring together. The ring represents an alicyclic hydrocarbon group having 4 to 12 carbon atoms, and —CH ₂ — contained in the alicyclic hydrocarbon group is a ring which may be replaced by —O— or —CO—. More preferably, it represents an alicyclic hydrocarbon group having 4 to 12 carbon atoms, and at least one of —CH ₂ — contained in the alicyclic hydrocarbon group is replaced by —O— or —CO—. More preferably, it is a ring.

［式（ＩＡ）中、
Ｒ^１、Ａ^１及びＬ^１は、上記と同義である。
Ｗ^１は、炭素数４〜１２の２価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−又は−ＣＯ−で置き換わっていてもよい。］ The structural unit represented by the formula (I) is preferably a structural unit represented by the formula (IA) (hereinafter sometimes referred to as “structural unit (IA)”).

[In the formula (IA),
R ¹ , A ¹ and L ¹ are as defined above.
W ¹ represents a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, and —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O— or —CO—. Good. ]

W ¹ represents a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, and at least one of —CH ₂ — contained in the alicyclic hydrocarbon group is replaced with —O— or —CO—. It is preferable. For example, W ¹ is preferably an alicyclic hydrocarbon group having one oxygen atom, two oxygen atoms, one carbonyl group or two oxygen atoms and one carbonyl group, and having two oxygen atoms More preferably, it is an alicyclic hydrocarbon group. In this case, a structure in which two oxygen atoms are adjacent via a carbon atom or a carbonyl group is preferable.
The two bonds of W ¹ may be present on different atoms, but are preferably present on the same atom.

Examples of W ¹ include the following groups.

Examples of the structural unit (I) and the structural unit (IA) include the structural units represented below.

In the structural units represented by formula (I-1) to formula (I-24), structural units in which the methyl group corresponding to R ¹ is replaced by a hydrogen atom are also exemplified as specific examples of structural unit (I). Can do. Of these, the structural units represented by formula (I-1) to formula (I-16) are preferable, and formula (I-2) to formula (I-5), formula (I-7), formula (I) -8), structural units represented by formula (I-10), formula (I-12), formula (I-13) to formula (I-15), respectively, are more preferable, and formula (I-2), formula The structural unit represented by each of (I-10), formula (I-13), and formula (I-15) is more preferred.

［式中、Ａ^１、Ｒ^１、Ｒ^２、Ｒ^３及びＬ^１は、上記と同じ意味を表す。］ <Method for Producing Compound Deriving Structural Unit (I)>
A compound from which the structural unit (I) is derived (hereinafter sometimes referred to as “compound (I)”) can be produced by the following method.

[Wherein, A ¹ , R ¹ , R ² , R ³ and L ¹ represent the same meaning as described above. ]

  That is, the compound (I) is obtained by reacting the compound represented by the formula (Ia) with the compound represented by the formula (Ib) in the presence of a base catalyst in a solvent. Can do.

［式中、Ｗ^１、Ｒ^１、Ｒ^２、Ｒ^３及びＡ^１は、上記と同じ意味を表す。］
溶媒としては、クロロホルム、テトラヒドロフランなどが挙げられる。
塩基触媒としては、例えば、トリエチルアミン、ジメチルアミノピリジンなどが挙げられる。
式（Ｉ−ａ）で表される化合物としては、下記式で表される塩等が挙げられ、市場より容易に入手することができし、容易に製造できる。

[Wherein W ¹ , R ¹ , R ² , R ³ and A ¹ represent the same meaning as described above. ]
Examples of the solvent include chloroform and tetrahydrofuran.
Examples of the base catalyst include triethylamine and dimethylaminopyridine.
Examples of the compound represented by the formula (Ia) include salts represented by the following formula and the like, which can be easily obtained from the market and can be easily produced.

  The content of the structural unit (I) in the resin (A) of the present invention is preferably 5 to 40 mol%, more preferably 7 to 4%, based on the total of all structural units of the resin (A) of the present invention. It is 35 mol%, More preferably, it is 8-30 mol%, Most preferably, it is 10-25 mol%.

<Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”). An “acid-labile group” has a leaving group, and the leaving group is eliminated by contact with an acid, so that the structural unit is converted into a structural unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). Meaning a group.

［式（１）中、Ｒ^ａ１〜Ｒ^ａ３は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合せた基を表すか、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２価の脂環式炭化水素基を形成する。
ｎａは、０又は１を表す。
＊は結合手を表す。］ The acid labile group contained in the resin (A) is preferably the group (1) and / or the group (2).

[In the formula (1), R ^{a1 to} R ^a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof, or R ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
na represents 0 or 1.
* Represents a bond. ]

［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２価の複素環基を形成し、該炭化水素基及び該２価の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。
＊は結合手を表す。］

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

^Examples of the alkyl group of R ^{a1 to} R ^a3 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.
The alicyclic hydrocarbon group for R ^{a1 to} R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups (* represents a bond). The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 is preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms.

Examples of the combination of an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, and a norbornylethyl group. Can be mentioned.
na is preferably 0.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group include the following groups. The divalent alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^{a1 to} R ^a3 are alkyl groups in the formula (1), preferably a tert-butoxycarbonyl group), 2- An alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and a carbon atom to which they are bonded form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantane- 1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

Examples of the hydrocarbon group of R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
^{Examples of the} divalent heterocyclic group formed together with the carbon atom to which R ^{a2 ′} and R ^{a3 ′} are bonded to each other and X, and X include the following groups. * Represents a bond.

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。

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

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

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

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

  As a structural unit derived from a (meth) acrylic monomer having a group represented by the formula (1), a structural unit represented by the formula (a1-0) is preferably represented by the formula (a1-1). The structural unit represented by a structural unit or a formula (a1-2) is mentioned. These may be used alone or in combination of two or more. In this specification, the structural unit represented by formula (a1-0), the structural unit represented by formula (a1-1), and the structural unit represented by formula (a1-2) are each represented by structural unit (a1). -0), structural unit (a1-1) and structural unit (a1-2), a monomer for deriving structural unit (a1-0), a monomer for deriving structural unit (a1-1), and a structural unit (a1- The monomer that induces 2) may be referred to as monomer (a1-0), monomer (a1-1), and monomer (a1-2), respectively.

［式（ａ１−０）中、
Ｌ^ａ０１は、酸素原子又は^＊−Ｏ−（ＣＨ_２）_ｋ０１−ＣＯ−Ｏ−を表し、ｋ０１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。
Ｒ^ａ０１は、水素原子又はメチル基を表す。
Ｒ^ａ０２〜Ｒ^ａ０４は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合せた基を表す。］

[In the formula (a1-0),
L ^a01 represents an oxygen atom or ^* —O— (CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond with a carbonyl group.
R ^a01 represents a hydrogen atom or a methyl group.
R ^{a02 to} R ^a04 each independently ^represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof. ]

［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の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合せることにより形成される基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ１’は０〜３の整数を表す。］

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

L ^a01 is preferably an oxygen atom or ^* —O— (CH ₂ ) _k01 —CO—O— (where k01 is preferably an integer of 1 to 4, more preferably 1), and more. Preferably it is an oxygen atom.
Examples of the alkyl group of R ^{a02 to} R ^a04 , the alicyclic hydrocarbon group, and a group obtained by combining these include the same groups as those ^exemplified for R ^{a1 to} R ^a3 of formula (1).
Carbon number of the alkyl group of R ^{a02 to} R ^a04 is preferably 6 or less.
Carbon number of the alicyclic hydrocarbon group of R ^{a02 to} R ^a04 is preferably 8 or less, more preferably 6 or less.
The group in which the alkyl group and the alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in combination of the alkyl group and the alicyclic hydrocarbon group. Examples of such groups include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a methyladamantyl group, a cyclohexylmethyl group, a methylcyclohexylmethyl group, an adamantylmethyl group, and a norbornylmethyl group. It is done.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group.

L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _{k1 ′} —CO—O— (where k1 ′ is an integer of 1 to 4, preferably 1). More preferably -O-.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and the group obtained by combining these include the same groups as those ^exemplified for R ^{a1 to} R ^a3 of formula (1).
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The carbon number of the alicyclic hydrocarbon group of R ^a6 and R ^a7 is preferably 8 or less, more preferably 6 or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

  As the monomer (a1-0), for example, a monomer represented by any one of the formulas (a1-0-1) to (a1-0-12) is preferable, and the formula (a1-0-1) to the formula ( A monomer represented by any one of a1-0-10) is more preferable.

In the above structural unit, a structural unit in which a methyl group corresponding to R ^a01 is replaced by a hydrogen atom can also be given as a specific example of the structural unit (a1-0).

  As a monomer (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Among these, a monomer represented by any one of formula (a1-1-1) to formula (a1-1-8) is preferable, and any one of formula (a1-1-1) to formula (a1-1-4) is preferable. The monomer represented by is more preferable.

  Examples of the monomer (a1-2) include 1-methylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclopentan-1-yl (meth) acrylate, and 1-methylcyclohexane-1-yl (meth). Acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, 1-ethylcycloheptan-1-yl (meth) acrylate, 1-ethylcyclooctane-1-yl (meth) acrylate, 1-isopropylcyclopentane-1 -Yl (meth) acrylate, 1-isopropylcyclohexane-1-yl (meth) acrylate, etc. are mentioned. A monomer represented by any one of the formulas (a1-2-1) to (a1-2-12) is preferable, and the formula (a1-2-3), the formula (a1-2-4), the formula (a1- 2-9) and a monomer represented by formula (a1-2-10) are more preferred, and a monomer represented by formula (a1-2-3) and formula (a1-2-9) is more preferred.

  When the resin (A) includes the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is the total structure of the resin (A). It is 10-95 mol% normally with respect to the sum total of a unit, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

  Furthermore, examples of the structural unit (a1) having the group (1) include a structural unit represented by the formula (a1-3). The structural unit represented by the formula (a1-3) may be referred to as a structural unit (a1-3). Moreover, the monomer which derives the structural unit (a1-3) may be referred to as a monomer (a1-3).

［式（ａ１−３）中、
Ｒ^ａ９は、ヒドロキシ基を有していてもよい炭素数１〜３の脂肪族炭化水素基、カルボキシ基、シアノ基、水素原子又は−ＣＯＯＲ^ａ１３を表す。
Ｒ^ａ１３は、炭素数１〜８の脂肪族炭化水素基、炭素数３〜２０の脂環式炭化水素基、又はこれらを組合せることにより形成される基を表し、該脂肪族炭化水素基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基で置換されていてもよく、該脂肪族炭化水素基及び該脂環式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。
Ｒ^ａ１０〜Ｒ^ａ１２は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合せることにより形成される基を表すか、Ｒ^ａ１０及びＲ^ａ１１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２価の脂環式炭化水素基を形成する。］

[In the formula (a1-3),
R ^a9 represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxy group, a carboxy group, a cyano group, a hydrogen atom, or —COOR ^a13 .
R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these, and the aliphatic hydrocarbon group and The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group, and —CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is —O—. Alternatively, it may be replaced by -CO-.
R ^{a10 to} R ^a12 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these, or R ^a10 and R ^a11 is bonded to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. ]

Examples of the aliphatic hydrocarbon group which may have a hydroxyl group of ^Ra9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
^Examples of —COOR ^a13 include a group in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms for R ^a13 include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, n -Hexyl group, n-heptyl group, 2-ethylhexyl group, n-octyl group, etc. are mentioned.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by Ra13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantylmethyl group, a 1-adamantyl-1-methylethyl group, and 2-oxo-oxolane-3- Yl group and 2-oxo-oxolan-4-yl group.
^Examples of the alkyl group for R ^{a10 to} R ^a12 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, Examples include n-heptyl group, 2-ethylhexyl group, n-octyl group and the like.
The alicyclic hydrocarbon group for R ^{a10 to} R ^a12 may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, and a cyclopentyl group. And cycloalkyl groups such as a group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cycloheptyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, and norbornyl. Group, methylnorbornyl group, isobornyl group and the like.
As —C (R ^a10 ) (R ^a11 ) (R ^a12 ) when R ^a10 and R ^a11 are bonded to each other to form a divalent alicyclic hydrocarbon group together with the carbon atom to which they are bonded, The following groups are preferred.

  Specific examples of the monomer (a1-3) include 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, and 5-norbornene-2-carboxylic acid. Acid 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1- (4 -Methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4-oxo (Cyclohexyl) ethyl and 1- (1-adamantyl) -1-methyl 5-norbornene-2-carboxylate Chill, and the like.

  Since the resin (A) containing the structural unit (a1-3) includes a sterically bulky structural unit, the resist composition of the present invention containing such a resin (A) is more expensive. A resist pattern can be obtained with resolution. Further, since a rigid norbornane ring is introduced into the main chain, the resulting resist pattern tends to be excellent in dry etching resistance.

  When resin (A) contains a structural unit (a1-3), it is preferable that the content rate is 10-95 mol% with respect to the sum total of all the structural units of resin (A), 15-90 mol. % Is more preferable, and 20 to 85 mol% is still more preferable.

  As the structural unit (a1) having a group represented by the group (2), a structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as “structural unit (a1-4)”). Can be mentioned.

［式（ａ１−４）中、
Ｒ^ａ３２は、水素原子、ハロゲン原子、又は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^ａ３３は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
ｌａは０〜４の整数を表す。ｌａが２以上である場合、複数のＲ^ａ３３は互いに同一であっても異なってもよい。
Ｒ^ａ３４及びＲ^ａ３５はそれぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ３６は、炭素数１〜２０の炭化水素基を表すか、Ｒ^ａ３５及びＲ^ａ３６は互いに結合してそれらが結合するＣ−Ｏとともに炭素数３〜２０の２価の複素環基を形成し、該炭化水素基及び該２価の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。］

[In the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
la represents an integer of 0 to 4. When la is 2 or more, the plurality of R ^a33 may be the same as or different from each other.
R ^a34 and ^{R a35} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon ^{atoms, R a36} may represent a hydrocarbon group having 1 to 20 carbon ^{atoms, R a35} and ^{R a36} are bonded to each other And C—O to which they are bonded to form a divalent heterocyclic group having 3 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent heterocyclic group is —O— Alternatively, it may be replaced by -S-. ]

^Examples of the alkyl group for R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, and a hexyl group. As this alkyl group, a C1-C4 alkyl group is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is further more preferable.
Examples of the halogen atom for R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, and a bromine atom.
The R ^a34 and ^{R a35,} include the same groups as ^{R a1 'and R a2'} of formula (2).
R ^a36 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 a combination thereof. Can be mentioned.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group and an ethoxy group, and further preferably a methoxy group.
la is preferably 0 or 1, and more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a methyl group or an ethyl group.
The hydrocarbon group for ^Ra36 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. More preferably, a C1-C18 alkyl group, a C3-C18 alicyclic aliphatic hydrocarbon group, or a C7-C18 aralkyl group is mentioned. The alkyl group and the alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. When the aromatic hydrocarbon group in R ^a36 has a substituent, the substituent is preferably an aryloxy group having 6 to 10 carbon atoms.

  As a monomer which introduce | transduces structural unit (a1-4), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Among these, monomers represented by formula (a1-4-1) to formula (a1-4-8) are preferable, and formula (a1-4-1) to formula (a1-4-5) and formula (a1- The monomers represented by 4-8) are more preferable.

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

  As a structural unit derived from a (meth) acrylic monomer having a group represented by the formula (2), a structural unit represented by the formula (a1-5) (hereinafter referred to as “structural unit (a1-5)”) Is also included).

［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＊−（ＣＨ_２）_ｈ３−ＣＯ−Ｌ^５４−を表し、ｈ３は１〜４の整数を表し、＊は、Ｌ^５１との結合手を表す。
Ｌ^５１〜Ｌ^５４は、それぞれ独立に、−Ｏ−又は−Ｓ−を表す。
ｓ１は、１〜３の整数を表す。
ｓ１’は、０〜３の整数を表す。］

[In the formula (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or * — (CH ₂ ) _{h 3} —CO—L ⁵⁴ —, h 3 represents an integer of 1 to 4, and * represents a bond to L ⁵¹ .
L ^{51 to} L ⁵⁴ each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3. ]

As a halogen atom, a fluorine atom and a chlorine atom are mentioned, Preferably a fluorine atom is mentioned. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom 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 fluoromethyl group and a trifluoromethyl group. Groups.
In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
One of L ⁵² and L ⁵³ is preferably —O—, and the other is preferably —S—.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

  As a monomer which introduce | transduces structural unit (a1-5), the monomer described in Unexamined-Japanese-Patent No. 2010-61117 is mentioned, for example. Among these, monomers represented by formulas (a1-5-1) to (a1-5-4) are preferable, and monomers represented by formula (a1-5-1) or formula (a1-5-2) are preferable. Is more preferable.

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

The structural unit (a1) having an acid labile group in the resin (A) includes the structural unit (a1-0), the structural unit (a1-1), the structural unit (a1-2), and the structural unit (a1-5). 1 type or more selected from the group consisting of: and more preferably two or more types, a combination of the structural unit (a1-1) and the structural unit (a1-2), the structural unit (a1-1) and the structural unit (a1- 5), a combination of structural unit (a1-1) and structural unit (a1-0), a combination of structural unit (a1-2) and structural unit (a1-0), a structural unit (a1-5) and a structure Combination of unit (a1-0), structural unit (a1-0), combination of structural unit (a1-1) and structural unit (a1-2), structural unit (a1-0), structural unit (a1-1) And a combination of the structural unit (a1-5) is more preferable. ) And combinations of the structural units (a1-2), the combination is more preferable than the structural units (a1-1) and the structural unit (a1-5).
The structural unit (a1) preferably includes the structural unit (a1-1).

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

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

  Examples of the structural unit (a2) having a phenolic hydroxy group include a structural unit represented by the formula (a2-0) (hereinafter sometimes referred to as “structural unit (a2-0)”).

［式（ａ２−０）中、
Ｒ^ａ３０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^ａ３１は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、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。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^ａ３１は互いに同一であっても異なってもよい。］

[In the formula (a2-0),
R ^a30 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a31 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 acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ^a31 may be the same as or different from each other. ]

^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom of R ^a30 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 1 , 1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl Group, n-perfluorohexyl group and the like. R ^a30 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.
The alkoxy group for R ^a31 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group.
As ma, 0, 1 or 2 is preferable, 0 or 1 is more preferable, and 0 is particularly preferable.

Examples of the monomer that derives the structural unit (a2-0) include monomers described in JP 2010-204634 A.
Among them, the structural unit (a2-0) is represented by the formula (a2-0-1), the formula (a2-0-2), the formula (a2-0-3), and the formula (a2-0-4), respectively. The structural unit represented by the formula (a2-0-1) or the formula (a2-0-2) is more preferable.

  The resin (A) containing the structural unit (a2-0) is subjected to a polymerization reaction using a monomer in which the phenolic hydroxy group of the monomer that derives the structural unit (a2-0) is protected with a protective group, and then deprotected. It can be manufactured by processing. However, when the deprotection treatment is performed, the acid labile group of the structural unit (a1) needs to be not significantly impaired. Examples of such protecting groups include acetyl groups.

  When the resin (A) has a structural unit (a2-0) having a phenolic hydroxy group, the content is 5 to 95 mol% with respect to the total of all the structural units of the resin (A). Is preferable, it is more preferable that it is 10-80 mol%, and it is further more preferable that it is 15-80 mol%.

  Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”).

［式（ａ２−１）中、
Ｌ^ａ３は、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ２−ＣＯ−Ｏ−を表し、
ｋ２は１〜７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の整数を表す。］

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

In formula (a2-1), L ^a3 is preferably —O—, —O— (CH ₂ ) _f1 —CO—O— (wherein f1 is 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 monomer that derives the structural unit (a2-1) include monomers described in JP 2010-204646 A. A monomer represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable, and represented by any one of formula (a2-1-1) to formula (a2-1-4). The monomer represented by Formula (a2-1-1) or Formula (a2-1-3) is more preferable.

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

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

［式（ａ３−１）中、
Ｌ^ａ４は、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^ａ１８は、水素原子又はメチル基を表す。
Ｒ^ａ２１は炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は０〜５の整数を表す。ｐ１が２以上のとき、複数のＲ^ａ２１は互いに同一であっても異なってもよい。
式（ａ３−２）中、
Ｌ^ａ５は、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^ａ１９は、水素原子又はメチル基を表す。
Ｒ^ａ２２は、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。
ｑ１は、０〜３の整数を表す。ｑ１が２以上のとき、複数のＲ^ａ２２は互いに同一であっても異なってもよい。
式（ａ３−３）中、
Ｌ^ａ６は、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^ａ２０は、水素原子又はメチル基を表す。
Ｒ^ａ２３は、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。
ｒ１は、０〜３の整数を表す。ｒ１が２以上のとき、複数のＲ^ａ２３は互いに同一であっても異なってもよい。
式（ａ３−４）中、
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。
Ｌ^ａ７は、単結合、^＊−Ｌ^ａ８−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−Ｌ^ａ９−ＣＯ−Ｏ−又は^＊−Ｌ^ａ８−Ｏ−ＣＯ−Ｌ^ａ９−Ｏ−を表す。
＊はカルボニル基との結合手を表す。
Ｌ^ａ８及びＬ^ａ９は、互いに独立に、炭素数１〜６のアルカンジイル基を表す。］ The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). These 1 type may be contained independently and 2 or more types may be contained.

[In the formula (a3-1),
L ^a4 represents a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 may be the same as or different from each other.
In formula (a3-2),
L ^a5 represents a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 may be the same as or different from each other.
In formula (a3-3),
L ^a6 represents a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, the plurality of R ^a23 may be the same as or different from each other.
In formula (a3-4),
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom.
L ^a7 is a single bond, ^* —L ^a8 —O—, ^* —L ^a8 —CO—O—, ^* —L ^a8 —CO—O—L ^a9 —CO—O— or ^* —L ^a8 —O—CO ^-La9- O- is represented.
* Represents a bond with a carbonyl group.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms. ]

Examples of the halogen atom for R ^a24 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
^Examples of the alkyl group for R ^a24 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. An alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.
Examples of the alkyl group having a halogen atom of Ra ²⁴ include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluoro A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group, etc. are mentioned.

^Examples of the alkanediyl group of L ^a8 and L ^a9 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, 4-diyl group, 2-methylbutane-1,4-diyl group, etc. are mentioned.

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 are each independently preferably —O— or k— is an integer of 1 to 4 * —O— (CH ₂ ). a group represented by _{k 3} —CO—O—, more preferably —O— and * —O—CH ₂ —CO—O—, and still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

In formula (a3-4),
R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.
L ^a7 is preferably a single bond or ^* -L ^a8 —CO—O—, and more preferably a single bond, —CH ₂ —CO—O— or —C ₂ H ₄ —CO—O—.

  As monomers for deriving the structural unit (a3), monomers described in JP 2010-204646 A, monomers described in JP 2000-122294 A, monomers described in JP 2012-41274 A are listed. Can be mentioned. As the structural unit (a3), formula (a3-1-1) to formula (a3-1-4), formula (a3-2-1) to formula (a3-2-4), formula (a3-3) 1) to a structural unit represented by any one of formula (a3-3-4) and formula (a3-4-1) to formula (a3-4-6), The structural unit represented by any one of the formula (a3-1-2) and the formula (a3-2-3) to the formula (a3-2-4) is more preferable, and the formula (a3-1-1) or the formula ( The structural unit represented by a3-2-3) is more preferable.

In the structural units represented by the following formulas (a3-4-1) to (a3-4-6), compounds in which a methyl group corresponding to R ^a24 is replaced with a hydrogen atom are also structural units (a3-4). ).

When the resin (A) contains the structural unit (a3), the content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on the total of all the structural units of the resin (A). Yes, more preferably 10 to 60 mol%.
Moreover, the content rate of a structural unit (a3-1), a structural unit (a3-2), a structural unit (a3-3), and a structural unit (a3-4) is the sum total of all the structural units of resin (A), respectively. Is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, and still more preferably 10 to 50 mol%.

The resin (A) of the present invention may further have other structural units (hereinafter sometimes referred to as “structural units (t)”).
<Structural unit (t)>
As the structural unit (t), in addition to the structural unit (a2) and the structural unit (a3), a structural unit having a halogen atom (hereinafter sometimes referred to as “structural unit (a4)”) and a non-leaving hydrocarbon group. And a structural unit (hereinafter sometimes referred to as “structural unit (a5)”).

［式（ａ４−０）中、
Ｒ^５は、水素原子又はメチル基を表す。
Ｌ^４は、単結合又は炭素数１〜４の脂肪族飽和炭化水素基を表す。
Ｌ^３は、炭素数１〜８のペルフルオロアルカンジイル基を表す。
Ｒ^６は、水素原子又はフッ素原子を表す。］ As the structural unit (a4), a structural unit represented by formula (a4-0) can be given.

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a C 1-8 perfluoroalkanediyl group.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the aliphatic saturated hydrocarbon group for L ⁴ include an alkanediyl group having 1 to 4 carbon atoms, such as a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1,4-diyl group. Having a side chain of an alkyl group (particularly, methyl group, ethyl group, etc.), ethane-1,1-diyl group, propane-1, Examples thereof include branched alkanediyl groups such as 2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.

As the perfluoroalkanediyl group of L ³ , a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane-2,2 -Diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2 -Diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7 -Diyl group, perfluoroheptane-2 , 2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3 , 3-diyl group, perfluorooctane-4,4-diyl group, and the like.

L ⁴ is preferably a single bond, a methylene group or an ethylene group, and more preferably a single bond or a methylene group.
L ³ is preferably a C 1-6 perfluoroalkanediyl group, and more preferably a C ^1-3 C perfluoroalkanediyl group.

  Examples of the structural unit (a4-0) include the structural units shown below.

［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の炭化水素基を表し、該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。］ As the structural unit (a4), a structural unit represented by formula (a4-1) can be given.

[In the formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents an ^optionally substituted hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group may be replaced by —O— or —CO—. Good.
A ^a41 represents a ^C1-C6 alkanediyl group which may have a substituent or a group represented by the formula (a-g1). ]

［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の脂肪族炭化水素基を表す。
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。
＊で表される２つの結合手のうち、右側の＊が−Ｏ−ＣＯ−Ｒ^ａ４２との結合手である。］

[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a C1-C5 aliphatic hydrocarbon group which may have a single bond or a substituent.
X ^a41 and X ^a42 each independently represent —O—, —CO—, ^—CO —O— or —O—CO—.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less.
Among the two bonds represented by *, the * on the right side is a bond with —O—CO—R ^a42 . ]

^Examples of the hydrocarbon group for R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. Examples of chain aliphatic hydrocarbon groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and n-decyl. Group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group and n-octadecyl group. Cyclic aliphatic hydrocarbon groups include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and other cycloalkyl groups; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* is a bond) And a polycyclic alicyclic hydrocarbon group such as).

  Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a biphenylyl group, a phenanthryl group, and a fluorenyl group.

The hydrocarbon group for R ^a42 is preferably a chain or cyclic aliphatic hydrocarbon group or a group formed by a combination thereof, and may have a carbon-carbon unsaturated bond. And a cyclic aliphatic saturated hydrocarbon group and a group formed by combining these are more preferable.
^Examples of the substituent for R ^a42 include a halogen atom and a group represented by the formula (a-g3). As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, Preferably a fluorine atom is mentioned.

［式（ａ−ｇ３）中、
Ｘ^ａ４３は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^ａ４５は、少なくとも１つのハロゲン原子を有する炭素数３〜１７の脂肪族炭化水素基を表す。
＊はカルボニル基との結合手を表す。］
Ａ^ａ４５の脂肪族炭化水素基としては、Ｒ^ａ４２で例示したものと同様の基が挙げられる。

[In the formula (a-g3),
^Xa43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having 3 to 17 carbon atoms having at least one halogen atom.
* Represents a bond with a carbonyl group. ]
^Examples of the aliphatic hydrocarbon group for A ^{a45 include} the same groups as those exemplified for R ^a42 .

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (a-g3). .
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 still more preferably a carbon number. It is a 1-6 perfluoroalkyl group, Most preferably, it is a C1-C3 perfluoroalkyl group. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.
When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), including the number of carbons contained in the group represented by the formula (a-g3), the aliphatic hydrocarbon The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When it has a group represented by the formula (a-g3) as a substituent, the number is preferably 1.

  The aliphatic hydrocarbon having a group represented by the formula (a-g3) is more preferably a group represented by the formula (a-g2).

［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３〜１７の脂肪族炭化水素基を表す。
Ｘ^ａ４４は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^ａ４７は、ハロゲン原子を有していてもよい炭素数３〜１７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。］

[In the formula (a-g2),
A ^a46 represents an aliphatic hydrocarbon group having 3 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents an aliphatic hydrocarbon group having 3 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 number of carbon atoms of the aliphatic hydrocarbon group for A ^a46 is preferably 1 to 6, and more preferably 1 to 3.
The carbon number of the aliphatic hydrocarbon group for A ^a47 is preferably 4 to 15, more preferably 5 to 12, and further preferably a cyclohexyl group or an adamantyl group.

A more preferable structure of the partial structure represented by * -A ^a46 -X ^a44 -A ^a47 is the following structure.

^As the alkanediyl group of ^Aa41 , a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group Linear alkanediyl group such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples include branched alkanediyl groups such as 2-methylbutane-1,4-diyl group.
^Examples of the substituent in the alkanediyl group of ^Aa41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and still more preferably an ethylene group.

In the group represented by the formula (a-g1) of A ^a41 (hereinafter, sometimes referred to as “group (a-g1)”), A ^a44 is ^bonded to —O—CO—R ^a42 .
The aliphatic hydrocarbon group of A ^{a42 to} A ^a44 in the group (a-g1) may have a carbon-carbon unsaturated bond, but an aliphatic saturated hydrocarbon group is preferable. As the aliphatic saturated hydrocarbon group, an alkyl group (the alkyl group may be linear or branched), an alicyclic hydrocarbon group, and an alkyl group and an alicyclic hydrocarbon group are combined. An aliphatic hydrocarbon group formed by the above. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, Examples include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
^Examples of the substituent for the aliphatic hydrocarbon group of A ^{a42 to} A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably 0.

^Examples of the group (a-g1) in which X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, * and ** each represent a bond, and ** is a bond with —O—CO—R ^a42 .

［式（ａ４−２）中、
Ｒ^ｆ１は、水素原子又はメチル基を表す。
Ａ^ｆ１は、炭素数１〜６のアルカンジイル基を表す。
Ｒ^ｆ２は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］ As the structural unit represented by the formula (a4-1), structural units represented by the formula (a4-2) and the formula (a4-3) are preferable.

[In the formula (a4-2),
R ^f1 represents a hydrogen atom or a methyl group.
A ^f1 represents an alkanediyl group having 1 to 6 carbon atoms.
R ^f2 represents a C 1-10 hydrocarbon group having a fluorine atom. ]

As the alkanediyl group of A ^f1 , 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 , A straight-chain alkanediyl group such as hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 -Branched alkanediyl groups such as a diyl group, 1-methylbutane-1,4-diyl group, 2-methylbutane-1,4-diyl group.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain, a cyclic group, and a group formed by a combination thereof. As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferable.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group and 2 -An ethylhexyl group is mentioned.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, and cyclodecyl group. A cycloalkyl group is mentioned. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, norbornyl group, A methyl norbornyl group and an isobornyl group are mentioned.

Examples of the hydrocarbon group having a fluorine atom for R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Examples of the alkyl group having a fluorine atom include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, 1 , 1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2- Tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) Ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoro Pentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2, 3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group And a fluorinated alkyl group such as a perfluorohexyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

As A ^f1 in Formula (a4-2), an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.
R ^f1 is preferably a fluorinated alkyl group having 1 to 6 carbon atoms.

［式（ａ４−３）中、
Ｒ^ｆ１１は、水素原子又はメチル基を表す。
Ａ^ｆ１１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の脂肪族炭化水素基を表す。
Ｘ^ｆ１２は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^ｆ１４は、フッ素原子を有していてもよい炭素数１〜１７の脂肪族炭化水素基を表す。
ただし、Ａ^ｆ１３及びＡ^ｆ１４の少なくとも１つは、フッ素原子を有する脂肪族炭化水素基を表す。］

[In the formula (a4-3),
R ^f11 represents a hydrogen atom or a methyl group.
A ^f11 represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents a C 1-18 aliphatic hydrocarbon group which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 represents an aliphatic hydrocarbon group having a fluorine atom. ]

^Examples of the alkanediyl group of A ^f11 include the same groups as the alkanediyl group of A ^f1 .

The aliphatic hydrocarbon group for A ^f13 includes chain and cyclic aliphatic hydrocarbon groups, and divalent aliphatic hydrocarbon groups formed by combining them. The aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom for A ^f13 preferably includes an aliphatic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group. It is done.
Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; difluoromethylene group, perfluoroethylene Groups, perfluoroalkanediyl groups such as perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic aliphatic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent aliphatic hydrocarbon group include an adamantanediyl group, a norbornanediyl group, a perfluoroadamantanediyl group, and the like.

As the aliphatic hydrocarbon group for A ^f14 , one of a chain type and a cyclic type, and an aliphatic hydrocarbon group formed by combining them are included. The aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom.
Examples of the chain aliphatic hydrocarbon group which may have a fluorine atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 1,1 , 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, A heptyl group, a perfluoro heptyl group, an octyl group, a perfluorooctyl group, etc. are mentioned.
The cyclic aliphatic hydrocarbon group which may have a fluorine atom may be monocyclic or polycyclic. Examples of the group containing a monocyclic aliphatic hydrocarbon group include a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, and a perfluorocyclohexyl group. Examples of the group containing a polycyclic aliphatic hydrocarbon group include an adamantyl group, an adamantylmethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, and a perfluoroadamantylmethyl group.

In the formula ^{(a4-3), A f11} is preferably an ethylene group.
The aliphatic hydrocarbon group for A ^f13 is preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and more preferably an aliphatic hydrocarbon group having 2 to 3 carbon atoms.
The aliphatic hydrocarbon group for A ^f14 is preferably an aliphatic hydrocarbon group having 3 to 12 carbon atoms, and more preferably an aliphatic hydrocarbon group having 3 to 10 carbon atoms. 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.

As the structural unit represented by the formula (a4-2), structural units represented by the formula (a4-1-1) to the formula (a4-1-22) can be given.

Examples of the structural unit represented by formula (a4-3) include structural units represented by formula (a4-1′-1) to formula (a4-1′-22), respectively.

［式（ａ４−４）中、
Ｒ^ｆ２１は、水素原子又はメチル基を表す。
Ａ^ｆ２１は、−（ＣＨ_２）_ｊ１−、−（ＣＨ_２）_ｊ２−Ｏ−（ＣＨ_２）_ｊ３−又は−（ＣＨ_２）_ｊ４−ＣＯ−Ｏ−（ＣＨ_２）_ｊ５−を表す。
ｊ１〜ｊ５は、それぞれ独立に、１〜６の整数を表す。
Ｒ^ｆ２２は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］ Examples of the structural unit (a4) include a structural unit represented by the formula (a4-4).

[In the formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 _{is, - (CH 2) j1 -} , - (CH 2) j2 -O- (CH 2) j3 - or _{- (CH 2) j4 -CO-} O- (CH 2) j5 - represents a.
j1 to j5 each independently represents an integer of 1 to 6.
R ^f22 represents a C 1-10 hydrocarbon group having a fluorine atom. ]

^Examples of the hydrocarbon group having a fluorine atom of R ^f22 include the same hydrocarbon groups as R ^f2 in formula (a4-2). R ^f22 is preferably a ^C 1-10 alkyl group having a fluorine atom or a C 1-10 alicyclic hydrocarbon group having a fluorine atom, and a C 1-10 alkyl having a fluorine atom. It is more preferably a group, more preferably a C 1-6 alkyl group having a fluorine atom.

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

Examples of the structural unit represented by the formula (a4-4) include the following structural units.

  When resin (A) has a structural unit (a4), it is preferable that the content rate is 1-20 mol% with respect to the sum total of all the structural units of resin (A), and 2-15 mol% It is more preferable that it is 3 to 10 mol%.

Examples of the non-leaving hydrocarbon group that the structural unit (a5) has include a linear, branched, or cyclic hydrocarbon group. Especially, it is preferable that a structural unit (a5) is an alicyclic hydrocarbon group.
As a structural unit (a5), the structural unit represented by a formula (a5-1) is mentioned, for example.

［式（ａ５−１）中、
Ｒ^５１は、水素原子又はメチル基を表す。
Ｒ^５２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又はヒドロキシ基で置換されていてもよい。但し、Ｌ^５１との結合位置にある炭素原子に結合する水素原子は、炭素数１〜８の脂肪族炭化水素基で置換されない。
Ｌ^５１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メチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］

[In the formula (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group or hydroxy group having 1 to 8 carbon atoms. May be. However, the hydrogen atom bonded to the carbon atom at the coupling position with the L ⁵¹ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The alicyclic hydrocarbon group for R ⁵² may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Examples thereof include alkyl groups such as octyl group and 2-ethylhexyl group.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-hydroxyadamantyl group and a 3-methyladamantyl group.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group.

Examples of the divalent saturated hydrocarbon group for L ⁵¹ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent aliphatic saturated hydrocarbon group. It is done.
Examples of the divalent aliphatic saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

  Examples of the group in which the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group include groups represented by formulas (L1-1) to (L1-4). In the following formula, * represents a bond with an oxygen atom.

［式（Ｌ１−１）中、
Ｘ^ｘ１は、カルボニルオキシ基又はオキシカルボニル基を表す。
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^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。］

[In the formula (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.
In formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^{x5 to} L ^x7 is 15 or less.
In formula (L1-4),
L ^x8 and L ^x9 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total number of carbon atoms of L ^x8 , L ^x9 and W ^x1 is 15 or less. ]

L ^x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, 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, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, 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 ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantanediyl group.

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

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

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

Ｌ^５１は、好ましくは、単結合又は式（Ｌ１−１）で表される基である。 As group represented by a formula (L1-4), the bivalent group shown below is mentioned, for example.

L ⁵¹ is preferably a single bond or a group represented by the formula (L1-1).

Examples of the structural unit (a5-1) include the following.

In the formula (a5-1-19) to the formula (a5-1-27), a structural unit in which a methyl group corresponding to R ⁵¹ is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a5-1). it can.

  When resin (A) has a structural unit (a5), it is preferable that the content rate is 1-30 mol% with respect to the sum total of all the structural units of resin (A), and 2-20 mol% It is more preferable that it is 3-15 mol%.

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

The resin (A) is preferably a resin comprising the structural unit (I), the structural unit (a1), and the structural unit (s), that is, the compound (I), the monomer (a1), and the monomer (s ).
The structural unit (a1) is preferably at least one selected from the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), more preferably the structural unit ( a1-1) and a structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group).
The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by the formula (a2-1). The structural unit (a3) is preferably selected from the structural unit represented by the formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-4). At least one kind.

  The resin (A) may contain a structural unit derived from a monomer having an adamantyl group (particularly the structural unit (a1-1)) in an amount of 15 mol% or more based on the content of the structural unit (a1). preferable. When the content of the structural unit having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

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

<Resist composition>
The resist composition of the present invention contains a resin (A) and an acid generator (hereinafter sometimes referred to as “acid generator (B)”).
The resist composition of the present invention preferably further contains a resin (X).
The resist composition of the present invention preferably further contains a solvent (E) (hereinafter sometimes referred to as “solvent (E)”).
The resist composition of the present invention may further be a quencher (C) (hereinafter sometimes referred to as “quencher (C)”), particularly a weak acid inner salt (hereinafter referred to as “weak acid inner salt (D)”). It is preferable to contain a salt with weak acidity such as).

<Resin (X)>
As resin (X), resin which consists only of structural units (t) is mentioned, for example. Among these, a resin containing the structural unit (a4) (however, the structural unit (I) is not included) is preferable.
In the resin (X), the content of the structural unit (a4) is preferably 40 mol% or more, more preferably 45 mol% or more with respect to the total of all the structural units of the resin (X). And more preferably 50 mol% or more.

  Examples of the structural unit that the resin (X) may further include a structural unit derived from the structural unit (a1), the structural unit (a2), the structural unit (a3), and other known monomers. The resin (X) is preferably a resin composed only of the structural unit (t), and more preferably a resin composed of the structural unit (a4).

The weight average molecular weight of the resin (X) is preferably 8,000 or more (more preferably 10,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of the resin (X) is the same as that for the resin (A).
When the resist composition 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). Preferably it is 1-40 mass parts, Most preferably, it is 2-30 mass parts.

  The total content of the resin (A) and the resin (X) is preferably 80% by mass or more and 99% by mass or less with respect to the solid content of the resist composition. In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described later from the total amount of the resist composition. The solid content of the resist composition and the resin content relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
As the acid generator, any nonionic or ionic acid generator may be used. Examples of the nonionic acid generator include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

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

［式（Ｂ１）中、
Ｑ^１及びＱ^２は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
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炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の１価の脂環式炭化水素基を表し、該アルキル基及び該１価の脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — contained in the group and the monovalent alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group of Q ¹ and Q ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluoro group. A hexyl group etc. are mentioned.
Q ¹ and Q ² are preferably each independently a fluorine atom or a trifluoromethyl group, more preferably a fluorine atom.

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

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include any of formulas (b1-1) to (b1-3) The group represented by these is mentioned. In the formulas (b1-1) to (b1-3) and the following specific examples, * 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メチレン基は、酸素原子又はカルボニル基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メチレン基は、酸素原子又はカルボニル基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メチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ただし、Ｌ^ｂ６とＬ^ｂ７との炭素数合計は、２３以下である。］

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

In Formula (b1-1) to Formula (b1-3), when the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, the number of carbons before the replacement is represented by the carbon number of the saturated hydrocarbon group. It is a number.
Examples of the divalent saturated hydrocarbon group include the same divalent saturated hydrocarbon group of L ^b1.

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.

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

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

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

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

［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、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシ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、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシ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^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、ヒドロキシ基又はアシルオキシ基に置換されていてもよい。該アシルオキシ基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよく、該アシ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^ｂ２６の合計炭素数は２１以下である。］ Examples of formula (b1-3) include groups represented by formula (b1-9) to formula (b1-11), respectively.

[In the formula (b1-9),
L ^b19 represents a single bond or a ^C1-C23 divalent saturated hydrocarbon group, and the hydrogen atom contained in the divalent 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 divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group, or an acyloxy group. Also good. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In formula (b1-10),
L ^b21 represents a single bond or a ^C1-C21 divalent saturated hydrocarbon group, and the hydrogen atom contained in the divalent 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 divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group, or an acyloxy group. May be. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^{b21 to} L ^b23 is 21 or less.
In formula (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent 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 divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group, or an acyloxy group. May be. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be substituted with a hydroxy group.
^However, the total number of carbon atoms of L b24 ^{~L b26} is 21 or less. ]

  In formula (b1-10) and formula (b1-11), when a hydrogen atom contained in a divalent saturated hydrocarbon group is substituted with an acyloxy group, the number of carbon atoms in the acyloxy group, CO in the ester bond, and The number of carbon atoms of the divalent saturated hydrocarbon group including the number of O is used.

Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.
Examples of the acyloxy group having a substituent include an oxoadamantylcarbonyloxy group, a hydroxyadamantylcarbonyloxy group, an oxocyclohexylcarbonyloxy group, and a hydroxycyclohexylcarbonyloxy group.

Of the groups represented by formula (b1-1), examples of the group represented by formula (b1-4) include the following.

Of the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-5) include the following.

Of the groups represented by formula (b1-1), examples of the group represented by formula (b1-6) include the following.

Of the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-7) include the following.

Of the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-8) include the following.

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

Of the groups represented by formula (b1-3), examples of the group represented by formula (b1-9) include the following.

Of the groups represented by the formula (b1-3), examples of the group represented by the formula (b1-10) include the following.

Of the groups represented by formula (b1-3), examples of the group represented by formula (b1-11) include the following.

Examples of the alkyl group represented by Y include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, heptyl. Group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group and other alkyl groups, and preferably an alkyl group having 1 to 6 carbon atoms.
Examples of the monovalent alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11).
Examples of the group in which —CH ₂ — contained in the monovalent alicyclic hydrocarbon group represented by Y is replaced by —O—, —SO ₂ — or —CO— include formulas (Y12) to (Y26). The group represented by these is mentioned.

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of the substituent for the alkyl group represented by Y include a halogen atom, a hydroxy group, a monovalent n-alicyclic hydrocarbon group having 3 to 16 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. , A glycidyloxy group or — (CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms and a monovalent alicyclic hydrocarbon having 3 to 16 carbon atoms) Represents a group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and ja represents an integer of 0 to 4).
Examples of the substituent for the monovalent alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and 3 carbon atoms. -16 monovalent alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 monovalent aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C2 4 acyl group, glycidyloxy group or — (CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, monovalent fat having 3 to 16 carbon atoms) Represents a cyclic hydrocarbon group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and ja represents an integer of 0 to 4).

Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the monovalent aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. Groups, biphenyl groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of Y include the following.

When Y is an alkyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon at the bonding position with Y The group —CH ₂ — is preferably replaced by —O— or —CO—. In this case, -CH ₂ contained in the alkyl group Y - ^of, -CH ₂ in the coupling position of the ^{L b1} - is not Okikawara by -O- or -CO-.

  Y is preferably a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl group which may have a substituent. The methylene group constituting the group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. Y is particularly preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

  As the sulfonate anion in the salt represented by the formula (B1), an anion represented by the formula (B1-A-1) to the formula (B1-A-33) [hereinafter, anion (B1 -A-1) "or the like. ] Is preferable, Formula (B1-A-1)-Formula (B1-A-4), Formula (B1-A-9), Formula (B1-A-10), Formula (B1-A-24)-Formula An anion represented by any one of (B1-A-33) is more preferable.

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. R ⁱ⁸ is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. And more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group. L ⁴ is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q ¹ and Q ² are the same as described above.
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include the anions described in JP 2010-204646 A.

Examples of the sulfonate anion in the salt represented by the preferred formula (B1) include anions represented by formulas (B1a-1) to (B1a-15), respectively.

  Especially, the anion represented by either the formula (B1a-1)-a formula (B1a-3) and a formula (B1a-7)-a formula (B1a-15) is preferable.

Examples of the organic cation of Z ⁺ include an organic onium cation, such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation, and preferably an organic sulfonium cation or an organic iodonium cation. More preferably, an arylsulfonium cation is mentioned.
Z ⁺ in the formula (B1) is preferably a cation represented by any one of the formulas (b2-1) to (b2-4) [hereinafter referred to as “cation (b2-1)” or the like depending on the formula number, etc. There is a case. ].

［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１価の脂肪族炭化水素基、炭素数３〜３６の１価の脂環式炭化水素基又は炭素数６〜３６の１価の芳香族炭化水素基を表し、該１価の脂肪族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１価の脂環式炭化水素基又は炭素数６〜１８の１価の芳香族炭化水素基で置換されていてもよく、該１価の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１価の脂肪族炭化水素基、炭素数２〜４のアシ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１価の芳香族炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基又は炭素数１〜１２のアルコキシ基で置換されていてもよい。
Ｒ^ｂ４とＲ^ｂ５とは、それらが結合する硫黄原子とともに環を形成してもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ−又は−ＣＯ−に置き換わってもよい。
Ｒ^ｂ７及びＲ^ｂ８は、それぞれ独立に、ヒドロキシ基、炭素数１〜１２の１価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の整数を表す。
ｍ２が２以上のとき、複数のＲ^ｂ７は同一であっても異なってもよく、ｎ２が２以上のとき、複数のＲ^ｂ８は同一であっても異なってもよい。
Ｒ^ｂ９及びＲ^ｂ１０は、それぞれ独立に、炭素数１〜３６の１価の脂肪族炭化水素基又は炭素数３〜３６の１価の脂環式炭化水素基を表す。
Ｒ^ｂ９とＲ^ｂ１０とは、それらが結合する硫黄原子とともに環を形成してもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ−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１価の脂肪族炭化水素基、炭素数３〜３６の１価の脂環式炭化水素基又は炭素数６〜１８の１価の芳香族炭化水素基を表す。
Ｒ^ｂ１２は、炭素数１〜１２の１価の脂肪族炭化水素基、炭素数３〜１８の１価の脂環式炭化水素基又は炭素数６〜１８の１価の芳香族炭化水素基を表し、該１価の脂肪族炭化水素に含まれる水素原子は、炭素数６〜１８の１価の芳香族炭化水素基で置換されていてもよく、該１価の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、一緒になってそれらが結合する−ＣＨ−ＣＯ−を含む環を形成していてもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ−又は−ＣＯ−に置き換わってもよい。
Ｒ^ｂ１３〜Ｒ^ｂ１８は、それぞれ独立に、ヒドロキシ基、炭素数１〜１２の１価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、−Ｓ−又は−Ｏ−を表す。
ｏ２、ｐ２、ｓ２、及びｔ２は、それぞれ独立に、０〜５の整数を表す。
ｑ２及びｒ２は、それぞれ独立に、０〜４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は同一であっても異なってもよく、ｐ２が２以上のとき、複数のＲ^ｂ１４は同一であっても異なってもよく、ｑ２が２以上のとき、複数のＲ^ｂ１５は同一であっても異なってもよく、ｒ２が２以上のとき、複数のＲ^ｂ１６は同一であっても異なってもよく、ｓ２が２以上のとき、複数のＲ^ｂ１７は同一であっても異なってもよく、ｔ２が２以上のとき、複数のＲ^ｂ１８は同一であっても異なってもよい。］

[In Formula (b2-1)-Formula (b2-4),
R ^{b4 to} R ^b6 are each independently a monovalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent group having 6 to 36 carbon atoms. The hydrogen atom contained in the monovalent aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or a monovalent alicyclic carbon group having 3 to 12 carbon atoms. It may be substituted with a hydrogen group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the monovalent alicyclic hydrocarbon group is a halogen atom or a carbon number 1 to 18 Which may be substituted with a monovalent aliphatic hydrocarbon group, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, the hydrogen atom contained in the monovalent aromatic hydrocarbon group is a halogen atom, hydroxy Group or an alkoxy group having 1 to 12 carbon atoms may be substituted.
R ^b4 and R ^b5 may form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. .
R ^b7 and R ^b8 each independently represent a hydroxy group, a monovalent 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 ^b7 may be the same or different, and when n2 is 2 or more, the plurality of R ^b8 may be the same or different.
R ^b9 and R ^b10 each independently represent a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. .
R ^b11 represents a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent aromatic carbon group having 6 to 18 carbon atoms. Represents a hydrogen group.
R ^b12 represents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. And a hydrogen atom contained in the monovalent aliphatic hydrocarbon may be substituted with a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and is contained in the monovalent aromatic hydrocarbon group The hydrogen atom to be substituted may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may together form a ring containing —CH—CO— to which they are bonded, and —CH ₂ — contained in the ring is —O—, —SO—. Alternatively, it may be replaced by -CO-.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents -S- or -O-.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 may be the same or different. When p2 is 2 or more, the plurality of R ^b14 may be the same or different. When q2 is 2 or more The plurality of R ^b15 may be the same or different. When r2 is 2 or more, the plurality of R ^b16 may be the same or different. When s2 is 2 or more, the plurality of R ^b17 is ^They may be the same or different, and when t2 is 2 or more, the plurality of R ^b18 may be the same or different. ]

Monovalent aliphatic hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl and 2 -The alkyl group of an ethylhexyl group is mentioned. In particular, the monovalent aliphatic hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The monovalent alicyclic hydrocarbon group may be monocyclic or polycyclic, and the monocyclic monovalent alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Examples thereof include cycloalkyl groups such as a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic monovalent alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups.

In particular, the carbon number of the monovalent alicyclic hydrocarbon group of R ^{b9 to} R ^b12 is preferably 3 to 18, and more preferably 4 to 12.

  Examples of the monovalent alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, and a methylnorbornyl group. Group, isobornyl group and the like. In the monovalent alicyclic hydrocarbon group in which the hydrogen atom is substituted with a monovalent aliphatic hydrocarbon group, the total number of carbon atoms of the monovalent alicyclic hydrocarbon group and the monovalent aliphatic hydrocarbon group Is preferably 20 or less.

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

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

The ring that R ^b4 and R ^b5 may form together with the sulfur atom to which they are bonded is any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. There may be. As this ring, a C3-C18 ring is mentioned, Preferably a C4-C18 ring is mentioned. Moreover, as a ring containing a sulfur atom, 3-membered ring-12-membered ring are mentioned, Preferably 3-membered ring-7-membered ring are mentioned, Specifically, the following ring is mentioned.

The ring formed by R ^b9 and R ^b10 together with the sulfur atom to which they are bonded may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Good. Examples of the ring include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include a thiolane-1-ium ring (tetrahydrothiophenium ring) and thian-1-ium ring. Ring, 1,4-oxathian-4-ium ring and the like.
The ring formed by ^combining R ^b11 and R ^b12 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of the ring include 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. It is done.

Among the cation (b2-1) to cation (b2-4), the cation (b2-1) is preferable, and a cation represented by the formula (b2-1-1) (hereinafter referred to as “cation ( b2-1-1) "), more preferably triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (formula In (b2-1-1), v2 = w2 = 0, x2 = 1, R ^b21 is a methyl group) or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 1, and R ^{b19 to} R ^b21 are all methyl groups).

［式（ｂ２−１−１）中、
Ｒ^ｂ１９、Ｒ^ｂ２０及びＲ^ｂ２１は、それぞれ独立に、ハロゲン原子、ヒドロキシ基、炭素数１〜１８の１価の脂肪族炭化水素基、炭素数１〜１２のアルコキシ基又は炭素数３〜１８の１価の脂環式炭化水素基を表す。また、Ｒ^ｂ１９〜Ｒ^ｂ２１から選ばれる２つが一緒になって硫黄原子を含む環を形成してもよい。
ｖ２、ｗ２及びｘ２は、それぞれ独立に０〜５の整数を表す。
ｖ２が２以上のとき、複数のＲ^ｂ１９は同一であっても異なってもよく、ｗ２が２以上のとき、複数のＲ^ｂ２０は同一であっても異なってもよく、ｘ２が２以上のとき、複数のＲ^ｂ２１は同一であっても異なってもよい。］

[In the formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom, a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or a carbon atom having 3 to 18 carbon atoms. Represents a monovalent alicyclic hydrocarbon group. It is ^also possible that two selected from R b19 ^{to R b21} together form a ring containing a sulfur atom.
v2, w2 and x2 each independently represent an integer of 0 to 5.
When v2 is 2 or more, the plurality of R ^b19 may be the same or different. When w2 is 2 or more, the plurality of R ^b20 may be the same or different. When x2 is 2 or more The plurality of R ^b21 may be the same or different. ]

Ring or two of R ^b19 to R ^b21 is that together form a monocyclic, polycyclic, aromatic, may be any ring nonaromatic, one or more sulfur atoms If included, it may further contain one or more sulfur atoms and / or one or more oxygen atoms.
The monovalent aliphatic hydrocarbon group of R ^{b19 to} R ^b21 preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.

Among them, R ^b19 , R ^b20, and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, or 1 to 12 carbon atoms. or represents a alkoxy group, it is preferable two selected from R ^b19 to R ^b21 is that together form a ring containing an oxygen atom and a sulfur atom.
v2, w2 and x2 are each independently preferably 0 or 1.

  Specific examples of the cation (b2-1-1) include cations described in JP 2010-204646 A.

  The acid generator (B1) is a combination of the above-described sulfonate anion and the above-mentioned organic cation, and these can be arbitrarily combined. The acid generator (B1) is preferably an anion and a cation (b2) represented by any of the formulas (B1a-1) to (B1a-3) and (B1a-7) to (B1a-15). -1-1) or a combination with a cation (b2-3).

  Preferred examples of the acid generator (B1) include those represented by formulas (B1-1) to (B1-28). Among them, the formula (B1-1) and formula (B1) containing an arylsulfonium cation. -2), Formula (B1-3), Formula (B1-5), Formula (B1-6), Formula (B1-7), Formula (B1-11), Formula (B1-12), Formula (B1- 13), Formula (B1-14), Formula (B1-13), Formula (B1-20), Formula (B1-21), Formula (B1-23), Formula (B1-24), Formula (B1-25) ) Or the formula (B1-26) respectively is particularly preferable.

The content of the acid generator (B1) is preferably 30% by mass or more and 100% by mass or less, and more preferably 50% by mass or more and 100% by mass or less, with respect to the total amount of the acid generator (B). Preferably, it is more preferably substantially only the acid generator (B1).
The content of the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably 25 parts by mass) with respect to 100 parts by mass of the resin (A). Part or less). The resist composition of the present invention may contain one or more acid generators (B).

<Solvent (E)>
The content of the solvent (E) is usually 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, and usually 99.9% by mass or less, preferably 99% by mass or less in the resist composition. It is. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a 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, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may contain 1 type independently, and may contain 2 or more types.

<Quencher (C)>
Examples of the quencher (C) include a salt having a lower acidity than an acid generated from a basic nitrogen-containing organic compound or an acid generator (B).
Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

  Examples of the amine include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine, Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, tri Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, Rudicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyl Didecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, piperazine, morpholine, piperidine and JP-A-11- Hindered amine compounds having a piperidine skeleton described in Japanese Patent No. 2575, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ) Ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) Examples include ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipicolylamine, bipyridine, and the like. Includes diisopropylaniline, particularly preferably 2,6-diisopropylaniline.

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

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, a weak acid inner salt represented by the formula (D), and Examples include the salts described in JP-A No. 229206, JP-A 2012-6908, JP-A 2012-72109, JP-A 2011-39502, and JP-A 2011-191745. Preferably, it is a weak acid inner salt represented by the formula (D) (hereinafter sometimes referred to as “weak acid inner salt (D)”).
The acidity in a salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) is indicated by an acid dissociation constant (pKa). The salt that generates an acid having a lower acidity than the acid generated from the salt (I) and the acid generator (B) is a salt in which the acid dissociation constant of the acid generated from the salt is usually −3 <pKa, A salt of −1 <pKa <7 is preferable, and a salt of 0 <pKa <5 is more preferable.

［式（Ｄ）中、
Ｒ^Ｄ１及びＲ^Ｄ２は、それぞれ独立に、炭素数１〜１２の１価の炭化水素基、炭素数１〜６のアルコキシ基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基、炭素数２〜７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、それぞれ独立に、０〜４の整数を表し、ｍ’が２以上の場合、複数のＲ^Ｄ１は同一であっても異なってもよく、ｎ’が２以上の場合、複数のＲ^Ｄ２は同一であっても異なってもよい。］

[In the formula (D),
R ^D1 and R ^D2 are each independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, or an acyloxy group having 2 to 7 carbon atoms. Represents an alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group or a halogen atom.
m ′ and n ′ each independently represents an integer of 0 to 4, and when m ′ is 2 or more, a plurality of R ^D1 may be the same or different, and when n ′ is 2 or more, The plurality of R ^D2 may be the same or different. ]

In the weak acid inner salt (D), the hydrocarbon groups of R ^D1 and R ^D2 include a monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group, and Examples include groups formed by combining these.
Examples of the monovalent aliphatic hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, and nonyl group.
The monovalent alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be either saturated or unsaturated. Examples thereof include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, and cyclododecyl group, norbornyl group, adamantyl group, and the like.
Examples of the monovalent aromatic hydrocarbon group include phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4- Propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group , Aryl groups such as cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the group formed by combining these include an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, an aralkyl group (for example, phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl- 1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, etc.).

Examples of the alkoxy group include a methoxy group and an ethoxy group.
Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, and a cyclohexanecarbonyl group.
Examples of the acyloxy group include a group in which an oxy group (—O—) is bonded to the acyl group.
Examples of the alkoxycarbonyl group include a group in which a carbonyl group (—CO—) is bonded to the above alkoxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

In the formula (D), R ^D1 and R ^D2 are each independently an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or 2 to 2 carbon atoms. Preferred are an acyl group having 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group, or a halogen atom.
m ′ and n ′ are each independently preferably an integer of 0 to 2, and more preferably 0. When m ′ is 2 or more, the plurality of R ^D1 may be the same or different, and when n ′ is 2 or more, the plurality of R ^D2 may be the same or different.

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

  The weak acid inner salt (D) can be produced by the method described in “Tetrahedron Vol. 45, No. 19, p6281-6296”. A commercially available compound can be used as the weak acid inner salt (D).

  The content of the quencher (C) is preferably 0.01 to 5% by mass, more preferably 0.01 to 4% by mass, and particularly preferably 0.01 to 3% by mass in the solid content of the resist composition. %.

<Other ingredients>
The resist composition may contain components other than those described above (hereinafter may be referred to as “other components (F)”) as necessary. As the other component (F), known additives in the resist field, such as a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, a dye, and the like can be used.

<Preparation of resist composition>
The resist composition is prepared by mixing the resin (A) and the acid generator (B), and if necessary, the resin (X), the solvent (E), the quencher (C), and other components (F). can do. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature from 10-40 degreeC according to the kind etc. of resin etc., the solubility with respect to solvents (E), such as resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) A step of applying the resist composition of the present invention on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

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

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

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

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

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

In the case of producing a negative resist pattern from a resist composition, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and substantially only the organic solvent. More preferably.
As the organic developer, a developer containing butyl acetate and / or 2-heptanone is preferable. In the organic developer, the total content of butyl acetate and 2-heptanone 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. More preferably, it is only butyl acetate and / or 2-heptanone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a different type from the organic developer.

It is preferable to wash the developed resist pattern with a rinse solution. The rinsing liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After the cleaning, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

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

An example is given and it demonstrates more concretely. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

  The structure of the compound was confirmed by measuring molecular peaks using mass spectrometry (LC: Agilent model 1100, MASS: Agilent LC / MSD model). In the following examples, the value of this molecular peak is indicated by “MASS”.

Synthesis Example 1 [Synthesis of Compound Represented by Formula (I-2)]

  20 parts of a compound represented by formula (I-2-a), 100 parts of a compound represented by formula (I-2-b) and 0.13 part of a compound represented by formula (I-2-c) The mixture was stirred and stirred at 23 ° C. for 30 minutes, and further stirred at 80 ° C. for 6 hours under reflux. The resulting reaction was concentrated. Thereafter, 250 parts of ethyl acetate and 75 parts of a 10% aqueous sodium hydrogen carbonate solution were added to the resulting concentrated residue, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated. To the recovered organic layer, 75 parts of ion-exchanged water was added, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated 5 times. The organic layer washed with water was concentrated, 60 parts of n-heptane was added to the concentrated mass, and the mixture was stirred at 23 ° C. for 30 minutes and filtered to obtain 18.58 parts of the compound represented by the formula (I-2-d). Got.

式（Ｉ−２−ｄ）で表される化合物１８．５５部、テトラヒドロフラン９５部、トリエチルアミン１４．７３部及びジメチルアミノピリジン０．５９部を仕込み、２３℃で３０分間攪拌した。その後、式（Ｉ−２−ｅ）で表される化合物１７．９５部を添加し、さらに、２３℃で１時間撹拌した。得られた反応物を濃縮し、得られた濃縮残に、クロロホルム１２５部及び１０％炭酸カリウム水溶液７５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、５％シュウ酸水溶液６５部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水６５部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を４回繰り返した。水洗した有機層に活性炭０．７７部を添加し、２３℃で３０分間攪拌し、ろ過した。回収されたろ液を濃縮することにより、式（Ｉ−２）で表される化合物２１．６８部を得た。
ＭＳ（質量分析）：２５９．１（分子イオンピーク）

18.55 parts of the compound represented by the formula (I-2-d), 95 parts of tetrahydrofuran, 14.73 parts of triethylamine and 0.59 part of dimethylaminopyridine were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 17.95 parts of a compound represented by the formula (I-2-e) was added, and the mixture was further stirred at 23 ° C. for 1 hour. The obtained reaction product was concentrated, and 125 parts of chloroform and 75 parts of a 10% aqueous potassium carbonate solution were added to the resulting concentrated residue, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated. To the collected organic layer, 65 parts of a 5% oxalic acid aqueous solution was added, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated. To the recovered organic layer, 65 parts of ion-exchanged water was added, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This washing operation was repeated 4 times. 0.77 parts of activated carbon was added to the organic layer washed with water, stirred at 23 ° C. for 30 minutes, and filtered. The recovered filtrate was concentrated to obtain 21.68 parts of a compound represented by the formula (I-2).
MS (mass spectrometry): 259.1 (molecular ion peak)

Synthesis Example 2 [Synthesis of salt represented by formula (B1-21)]

  30.00 parts of a compound represented by the formula (B1-21-b) obtained by the method described in JP-A-2008-209917, and a salt 35.50 represented by the formula (B1-21-a). Part, 100 parts of chloroform, and 50 parts of ion-exchanged water were stirred at 23 ° C. for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and 30 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 100 parts of tert-butyl methyl ether was added to the resulting residue, and the mixture was stirred at 23 ° C. for 30 minutes and filtered, whereby the salt represented by the formula (B1-21-c) 48. 57 parts were obtained.

式（Ｂ１−２１−ｃ）で表される塩２０．００部、式（Ｂ１−２１−ｄ）で表される化合物２．８４部及びモノクロロベンゼン２５０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．２１部を添加し、更に、１００℃で１時間攪拌した。得られた反応溶液を濃縮し、得られた残渣に、クロロホルム２００部及びイオン交換水５０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層にイオン交換水５０部を加えて２３℃で３０分間攪拌し、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、得られた残渣に、アセトニトリル５３．５１部に溶解し、濃縮した。その後、ｔｅｒｔ−ブチルメチルエーテル１１３．０５部を加えて攪拌し、ろ過することにより、式（Ｂ１−２１）で表される塩１０．４７部を得た。

20.00 parts of a salt represented by the formula (B1-21-c), 2.84 parts of a compound represented by the formula (B1-21-d) and 250 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . To the obtained mixed solution, 0.21 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 1 hour. The obtained reaction solution was concentrated, and 200 parts of chloroform and 50 parts of ion-exchanged water were added to the obtained residue, and the mixture was stirred at 23 ° C. for 30 minutes and separated to take out the organic layer. 50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes and separated to take out the organic layer. This washing operation was repeated 5 times. The obtained organic layer was concentrated, and the obtained residue was dissolved in 53.51 parts of acetonitrile and concentrated. Then, 113.05 parts of tert-butyl methyl ether was added and stirred, followed by filtration to obtain 10.47 parts of the salt represented by the formula (B1-21).

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (−) Spectrum): M ^- 339.1

式（Ｂ１−２２−ａ）で表される塩１１．２６部、式（Ｂ１−２２−ｂ）で表される化合物１０．００部、クロロホルム５０部及びイオン交換水２５部を仕込み、２３℃で１５時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、更に、クロロホルム層にイオン交換水１５部を添加し、水洗した。この操作を５回繰り返した。クロロホルム層を濃縮し、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて２３℃で３０分間攪拌し、ろ過することにより、式（Ｂ１−２２−ｃ）で表される塩１１．７５部を得た。 Synthesis Example 3 [Synthesis of Salt Represented by Formula (B1-22)]

11.26 parts of a salt represented by the formula (B1-22-a), 10.00 parts of a compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of ion-exchanged water were charged at 23 ° C. For 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the resulting residue, and the mixture was stirred at 23 ° C. for 30 minutes and filtered to obtain the salt represented by the formula (B1-22-c) 11. 75 parts were obtained.

式（Ｂ１−２２−ｃ）で表される塩１１．７１部、式（Ｂ１−２２−ｄ）で表される化合物１．７０部及びモノクロロベンゼン４６．８４部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．１２部を添加し、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮し、得られた残渣に、クロロホルム５０部及びイオン交換水１２．５０部を加えて２３℃で３０分間攪拌し、分液して有機層を取り出した。回収された有機層にイオン交換水１２．５０部を加えて２３℃で３０分間攪拌した。その後、分液して有機層を取り出した。この水洗操作を８回繰り返した。得られた有機層を濃縮し、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて攪拌した。その後、ろ過することにより、式（Ｂ１−２２）で表される塩６．８４部を得た。

11.71 parts of a salt represented by the formula (B1-22-c), 1.70 parts of a compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene were charged, and the mixture was charged at 23 ° C. for 30 minutes. Stir. To the obtained mixed liquid, 0.12 part of copper (II) dibenzoate was added, and the mixture was further stirred at 100 ° C. for 30 minutes. The obtained reaction solution was concentrated, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue, and the mixture was stirred at 23 ° C. for 30 minutes and separated to take out the organic layer. 12.50 parts of ion exchange water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes. Thereafter, the organic layer was separated by liquid separation. This washing operation was repeated 8 times. The obtained organic layer was concentrated, and 50 parts of tert-butyl methyl ether was added to the resulting residue and stirred. Then, 6.84 parts of salts represented by Formula (B1-22) were obtained by filtering.

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 323.0

Synthesis of Resin (A) The compound (monomer) used for the synthesis of resin (A) is shown below. Hereinafter, these compounds are referred to as “monomer (a1-1-2)” or the like according to the formula number.

Example 1 [Synthesis of Resin A1]
As the monomer, monomer (a1-1-2), monomer (a1-2-3), monomer (a2-1-1), monomer (a3-1-1), monomer (a3-2-3) and monomer ( I-2), the molar ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-1-1): monomer (a3) -2-3): The monomer (I-2)) was mixed so as to be 30: 14: 6: 20: 20: 10, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added. It was set as the solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin A1 having a weight average molecular weight of 7.5 × 10 ^{3 in} a yield of 68%. This resin A1 has the following structural units.

Example 2 [Synthesis of Resin A2]
As the monomer, the monomer (a1-1-2), the monomer (a1-2-3), the monomer (a2-1-1), the monomer (a3-2-3) and the monomer (I-2) Ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-2-3): monomer (I-2)) is 30:14: It mixed so that it might be set to 6:40:10, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain Resin A2 having a weight average molecular weight of 7.7 × 10 ^{3 in} a yield of 65%. This resin A2 has the following structural units.

Example 3 [Synthesis of Resin A3]
As the monomer, the monomer (a1-1-2), the monomer (a1-2-3), the monomer (a2-1-1), the monomer (a3-1-1) and the monomer (I-2) Ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-1-1): monomer (I-2)) is 30:14: It mixed so that it might be set to 6:40:10, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain Resin A3 having a weight average molecular weight of 7.4 × 10 ^{3 in} a yield of 69%. This resin A3 has the following structural units.

Example 4 [Synthesis of Resin A4]
As the monomer, the monomer (a1-1-2), the monomer (a1-2-3), the monomer (a2-1-1), the monomer (a3-4-2) and the monomer (I-2) Ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-4-2): monomer (I-2)) is 30:14: It mixed so that it might be set to 6:40:10, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain Resin A4 having a weight average molecular weight of 7.8 × 10 ^{3 in} a yield of 70%. This resin A4 has the following structural units.

Example 5 [Synthesis of Resin A5]
As the monomer, the monomer (a1-1-2), the monomer (a1-2-3), the monomer (a2-1-1), the monomer (a3-1-1) and the monomer (I-2) Ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-1-1): monomer (I-2)) is 40:25: The mixture was mixed to 25:10, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and then filtered to obtain Resin A5 having a weight average molecular weight of 8.9 × 10 ^{3 in} a yield of 73%. This resin A5 has the following structural units.

Synthesis Example 4 [Synthesis of Resin AX1]
As the monomer, monomer (a1-1-2), monomer (a2-1-1) and monomer (a3-1-1) were used, and the molar ratio [monomer (a1-1-2): monomer (a2-1) -1): monomer (a3-1-1))] was mixed at 50:25:25, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added to obtain a solution. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. These were heated at 75 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin AX1 having a molecular weight of 9.1 × 10 ³ was obtained in a yield of 66%. This resin AX1 has the following structural units.

Synthesis Example 5 [Synthesis of Resin X1]
Monomer (a4-1-7) was used as a monomer, and methyl isobutyl ketone 1.2 times the total monomer amount was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin is again dissolved in dioxane, and the resulting solution is poured into a methanol / water mixed solvent to precipitate the resin. The resin is filtered to obtain a resin X1 having a weight average molecular weight of 1.7 × 10 ^4. Obtained at a rate of 79%. This resin X1 has the following structural units.

(Preparation of resist composition)
Each of the components shown below was mixed in parts by mass shown in Table 1, dissolved in a solvent, and filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin (A)>
A1 to A5, AX, X1: Resin A1 to Resin A5, Resin AX, Resin X1

<Acid generator (B)>
B1-21: a salt represented by the formula (B1-21) B1-22: a salt represented by the formula (B1-22) B1-3: synthesized according to the examples of JP 2010-152341 A

<Quencher (C)>
D1: (Tokyo Chemical Industry Co., Ltd.)

<Solvent>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

<Manufacture of resist pattern and its evaluation>
An organic antireflective coating composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic reflective film having a thickness of 78 nm on the wafer. A prevention film was formed. Next, the resist composition was applied (spin coated) on the organic antireflection film so that the film thickness after drying (pre-baking) was 85 nm. After coating, the silicon wafer was pre-baked on a direct hot plate at the temperature described in the “PB” column of Table 1 for 60 seconds to form a composition layer. ArF excimer stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light) on a silicon wafer on which the composition layer is formed, and a contact hole pattern (hole pitch 100 nm) Using a mask for forming a hole diameter of 70 nm), the exposure amount was changed stepwise to perform exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, the silicon wafer was heated (post-exposure baking process) on a hot plate at a temperature described in the “PEB” column of Table 1 for 60 seconds. Next, this silicon wafer was subjected to paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution to obtain a resist pattern.

  In the resist pattern obtained after development, the exposure amount at which the hole diameter formed using the mask was 55 nm was defined as the effective sensitivity.

<Evaluation of CD uniformity (CDU)>
In terms of effective sensitivity, the hole diameter of the pattern formed by the mask was measured 24 times per hole, and the average value was taken as the average hole diameter of one hole. The average hole diameter was measured for 400 holes formed on the same silicon wafer with the mask, and the standard deviation was determined using these as the population.
When the standard deviation is less than 1.85 nm,
When the standard deviation is 1.85 nm or more and less than 2.00 nm, “◯”,
The case where the standard deviation was larger than 2.00 nm was judged as “x”.
The results are shown in Table 2. Numerical values in parentheses indicate standard deviation (nm).

  Since the resist composition of the present invention is excellent in CD uniformity of the resulting resist pattern, it is suitable for semiconductor microfabrication and is extremely useful industrially.

Claims (15)

A resin having a structural unit represented by the formula (I) and a structural unit having an acid labile group.

[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
R ² and R ³ each independently represent a hydrogen atom, a hydroxy group or a hydrocarbon group having 1 to 12 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O— or —CO—. R ² and R ³ may be combined to form a ring.
A ¹ represents a single bond, a divalent hydrocarbon group having 1 to 12 carbon atoms or ^{* -A 2 -X 1 - (A} 3 -X 2) a - (A 4) b - represents a. * Represents a bond with an oxygen atom.
A ^{2 to} A ⁴ each independently represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
X ¹ and X ² each independently represent —O—, —CO—O—, —O—CO— or —O—CO—O—.
a represents 0 or 1.
b represents 0 or 1.
L ¹ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms. ] A ¹ is, according to claim 1, wherein the resin is a single bond or a methylene group. The resin according to claim 1 or 2, wherein the structural unit represented by the formula (I) is a structural unit represented by the formula (IA).

[In the formula (IA),
R ¹ represents a hydrogen atom or a methyl group.
W ¹ represents a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, and —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O— or —CO—. Good.
A ¹ represents a single bond, a divalent hydrocarbon group having 1 to 12 carbon atoms or ^{* -A 2 -X 1 - (A} 3 -X 2) a - (A 4) b - represents a. * Represents a bond with an oxygen atom.
A ^{2 to} A ⁴ each independently represents a divalent hydrocarbon group having 1 to 12 carbon atoms.
X ¹ and X ² each independently represent —O—, —CO—O—, —O—CO— or —O—CO—O—.
a represents 0 or 1.
b represents 0 or 1.
L ¹ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms. ] W ¹ represents an alicyclic hydrocarbon group having 4 to 12 carbon atoms, and at least one of —CH ₂ — contained in the alicyclic hydrocarbon group is replaced by —O— or —CO—. The resin according to claim 3. The resin according to any one of claims 1 to 4, wherein the structural unit having an acid labile group is a structural unit represented by formula (a1-1) or formula (a1-2).

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]   The resin according to any one of claims 1 to 5, wherein the structural unit having an acid labile group includes a structural unit represented by formula (a1-1) or formula (a1-2).   The resin according to any one of claims 1 to 6, wherein the resin further comprises a structural unit having a hydroxy group. The resin according to claim 7, wherein the structural unit having a hydroxy group is a structural unit represented by the formula (a2-1).

[In the formula (a2-1),
L ^a3 represents —O— or ^* —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10. ]   The resin according to any one of claims 1 to 8, wherein the resin further comprises a structural unit having a lactone ring. The structural unit having a lactone ring is at least one selected from the group consisting of structural units represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4) The resin according to claim 9.

[In the formula (a3-1),
L ^a4 represents a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 may be the same as or different from each other.
In formula (a3-2),
L ^a5 represents a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 may be the same as or different from each other.
In formula (a3-3),
L ^a6 represents a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, the plurality of R ^a23 may be the same as or different from each other.
In formula (a3-4),
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom.
L ^a7 is a single bond, ^* —L ^a8 —O—, ^* —L ^a8 —CO—O—, ^* —L ^a8 —CO—O—L ^a9 —CO—O— or ^* —L ^a8 —O—CO ^-La9- O- is represented.
* Represents a bond with -O-.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms. ]   A resist composition comprising the resin according to claim 1 and an acid generator. The resist composition according to claim 11, wherein the acid generator is an acid generator represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — contained in the group and the monovalent alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]   Furthermore, the resist composition of Claim 11 or 12 containing resin containing the structural unit which has a fluorine atom.   The resist composition according to claim 10, further comprising a salt that generates an acid having a lower acidity than an acid generated from the acid generator. (1) The process of apply | coating the resist composition in any one of Claims 10-14 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.