JP6670694B2 - Resist composition and method for producing resist pattern - Google Patents

Description

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

特許文献２には、下記構造単位の組合せからなる樹脂（下図左から、モル比３０：３０：４０）を含むレジスト組成物が記載されている。

Patent Literature 1 describes a resist composition containing a resin composed of a combination of the following structural units (from the lower left in the figure, a molar ratio of 40:20:40).

Patent Document 2 describes a resist composition containing a resin composed of a combination of the following structural units (30:30:40 in molar ratio from the left in the figure below).

JP 2002-155118 A JP 2011-227463 A

  In some cases, the resist pattern formed from the above resist composition was not always satisfactory in terms of residue and line edge roughness (LER).

［式（Ｉ）中、
Ｒ^１は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ａ^１は、＊−Ａ^２−Ｏ−、＊−Ａ^２−ＣＯ−Ｏ−、＊−Ａ^２−ＣＯ−Ｏ−Ａ^３−ＣＯ−Ｏ−又は＊−Ａ^２−Ｏ−ＣＯ−Ａ^３−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ａ^２及びＡ^３は、互いに独立に、炭素数１〜６のアルカンジイル基を表す。
Ｒ^ａ２５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。
ｗ１は、０〜８の整数を表す。ｗ１が２以上のとき、複数のＲ^ａ２５は互いに同一であってもよく、異なってもよい。］

［式（ａ４−０）中、
Ｒ^５は、水素原子又はメチル基を表す。
Ｌ^５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又は炭素数３〜１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ^６は、水素原子又はフッ素原子を表す。］
［２］Ｌ^３が、炭素数１〜２のペルフルオロアルカンジイル基である［１］記載のレジスト組成物。
［３］Ｒ^６が、フッ素原子である［１］又は［２］記載のレジスト組成物。
［４］式（ａ４−０）で表される構造単位の含有率が、樹脂（Ａ１）の全構造単位の合計に対して、０．５モル％以上９．５モル％以下である［１］〜［３］のいずれか記載のレジスト組成物。
［５］酸不安定基を有する構造単位が、式（ａ１−１）で表される構造単位又は式（ａ１−２）で表される構造単位を有する［１］〜［４］のいずれか記載のレジスト組成物。

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^ａ１及びＬ^ａ２は、互いに独立に、−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、互いに独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、互いに独立に、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。
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］酸発生剤が、式（Ｂ１）で表される塩である［１］〜［５］のいずれか記載のレジスト組成物。

［式（Ｂ１）中、
Ｑ^１及びＱ^２は、互いに独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^ｂ１は、炭素数１〜２４の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３〜１８の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。］
［７］酸発生剤から発生する酸よりも酸性度の弱い酸を発生する塩をさらに含有する［１］〜［６］のいずれか記載のレジスト組成物。
［８］レジスト組成物が、フッ素原子を有する構造単位を含み、かつ、酸不安定基を有する構造単位を含まない樹脂（Ａ２）をさらに含有する［１］〜［７］のいずれか記載のレジスト組成物。
［９］（１）［１］〜［８］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。 The present invention includes the following inventions.
[1] A resin (A1) containing a structural unit represented by the formula (I), a structural unit represented by the formula (a4-0) and a structural unit having an acid labile group, and an acid generator. Resist composition.

[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ^{1 is, * - A 2 -O -,} * - A 2 -CO-O -, * - A 2 -CO-O-A 3 -CO-O- or ^{* -A 2 -O-CO-A} 3 Represents -O-.
* Represents a bond to -O-.
A ² and A ³ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
^Ra25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
w1 represents an integer of 0 to 8. When w1 is 2 or more, a plurality of ^Ra25s may be the same or different. ]

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁵ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]
[2] The resist composition according to [1], wherein L ³ is a perfluoroalkanediyl group having 1 to 2 carbon atoms.
[3] The resist composition according to [1] or [2], wherein R ⁶ is a fluorine atom.
[4] The content of the structural unit represented by the formula (a4-0) is 0.5 mol% or more and 9.5 mol% or less based on the total of all structural units of the resin (A1). ] The resist composition according to any one of [3].
[5] Any of [1] to [4], wherein the structural unit having an acid labile group has a structural unit represented by formula (a1-1) or a structural unit represented by formula (a1-2) The resist composition as described in the above.

[In the formulas (a1-1) and (a1-2),
L ^a1 and ^{L a2} independently of one another, -O- or _{* -O- (CH 2) k1 -CO} -O- the stands, k1 represents an integer of 1-7, * the binding of -CO- Represent hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents an integer of 0 to 14.
n1 represents the integer of 0-10.
n1 ′ represents an integer of 0 to 3. ]
[6] The resist composition according to any one of [1] to [5], wherein the acid generator is a salt represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, wherein the alkyl group and the monovalent it is, -O - - -CH ₂ contained in the alicyclic hydrocarbon group, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]
[7] The resist composition according to any one of [1] to [6], further including a salt that generates an acid having a lower acidity than the acid generated from the acid generator.
[8] The resist composition according to any one of [1] to [7], wherein the resist composition further contains a resin (A2) containing a structural unit having a fluorine atom and not containing a structural unit having an acid labile group. Resist composition.
[9] (1) a step of applying the resist composition according to any one of [1] to [8] on a substrate;
(2) drying the composition after application to form 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.

  ADVANTAGE OF THE INVENTION According to the resist composition of this invention, a residue does not generate | occur | produce and a resist pattern with favorable line edge roughness (LER) can be manufactured.

In this specification, “(meth) acrylate” means “at least one of acrylate and methacrylate”. Notations such as "(meth) acrylic acid" and "(meth) acryloyl" have the same meaning.
Unless otherwise specified, a group which can be linear or branched, such as an “aliphatic hydrocarbon group”, includes any of them. The “aromatic hydrocarbon group” also includes a group in which a hydrocarbon group is bonded to an aromatic ring. If stereoisomers are present, they include all stereoisomers.
In the present specification, the “solid content of the resist composition” means the sum of components excluding a solvent (E) described later from the total amount of the resist composition.

(Resist composition)
The resist composition of the present invention contains a resin (A1) and an acid generator (hereinafter sometimes referred to as “acid generator (B)”).
The resist composition may further contain a resin (A2) containing a structural unit having a fluorine atom and not containing a structural unit having an acid labile group.
Further, the resist composition includes a quencher (hereinafter, sometimes referred to as “quencher (C)”) and / or a solvent (hereinafter, referred to as “quencher (C)”) that generates an acid having a lower acidity than the acid generated from the acid generator. Solvent (E) ").

<Resin (A1)>
The resin (A1) includes a structural unit represented by the formula (I) (hereinafter sometimes referred to as “structural unit (I)”) and a structural unit represented by the formula (a4-0) (hereinafter referred to as “structural unit”). (A4-0) ") and a structural unit having an acid labile group (hereinafter sometimes referred to as" structural unit (a1) ").
An “acid labile group” in a structural unit is a group having a leaving group, which is eliminated by contact with an acid to have a hydrophilic group (eg, a hydroxy group or a carboxyl group). It means a group that is converted into a structural unit.
Further, the resin (A1) further includes a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”) and another structural unit (hereinafter referred to as “structural unit (t)”). And / or structural units known in the art.

［式（Ｉ）中、
Ｒ^１は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ａ^１は、＊−Ａ^２−Ｏ−、＊−Ａ^２−ＣＯ−Ｏ−、＊−Ａ^２−ＣＯ−Ｏ−Ａ^３−ＣＯ−Ｏ−又は＊−Ａ^２−Ｏ−ＣＯ−Ａ^３−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ａ^２及びＡ^３は、互いに独立に、炭素数１〜６のアルカンジイル基を表す。
Ｒ^ａ２５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。
ｗ１は、０〜８の整数を表す。ｗ１が２以上のとき、複数のＲ^ａ２５は互いに同一であってもよく、異なってもよい。］ <Structural unit (I)>
The resin (A1) has a structural unit (I).

[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ^{1 is, * - A 2 -O -,} * - A 2 -CO-O -, * - A 2 -CO-O-A 3 -CO-O- or ^{* -A 2 -O-CO-A} 3 Represents -O-.
* Represents a bond to -O-.
A ² and A ³ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
^Ra25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
w1 represents an integer of 0 to 8. When w1 is 2 or more, a plurality of ^Ra25s may be the same or different. ]

Examples of the halogen atom for R ¹ in the formula (I) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkyl group for R ¹ 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. , Preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom of R ^1, a trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, a perfluoro sec- butyl group, perfluoro-tert- butyl group, perfluoropentyl group, perfluoro Examples include a hexyl group, a trichloromethyl group, a tribromomethyl group and a triiodomethyl group.
R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom, a methyl group or an ethyl group.
Examples of the aliphatic hydrocarbon group for ^Ra25 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group.

Ｒ^ａ２５は、好ましくはカルボキシ基、シアノ基又はメチル基である。
ｗ１は、好ましくは０〜２の整数であり、より好ましくは０又は１である。 The alkanediyl group for A ² and A ³ includes a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5 -Diyl group and hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples include a 4-diyl group and a 2-methylbutane-1,4-diyl group.
A ¹ is preferably ^* -A 2 -CO-O-, more preferably an _-CH 2 -CO-O- or _-C 2 _H 4 is -CO-O-.
The bonding position of A ^{1 to} the homoadamantane ring is not particularly limited, and may be, for example, any of positions 1 to 11 as described below. Among them, the 2-position is preferred.

^Ra25 is preferably a carboxy group, a cyano group or a methyl group.
w1 is preferably an integer of 0 to 2, and more preferably 0 or 1.

Specific examples of the structural unit (I) include the following structural units and structural units in which a methyl group corresponding to R ¹ in the following structural units is replaced with a hydrogen atom. Among them, the structural units (II) to (I-6) are preferable.

［式（Ｉ’）中、Ｒ¹、Ｒ^ａ２５、ｗ１及びＡ^１は、上記と同じ意味を表す。］ The structural unit (I) is derived from a monomer represented by the formula (I ′) (hereinafter, sometimes referred to as “monomer (I ′)”).

[In the formula (I ′), R ¹ , R ^a25 , w1 and A ¹ represent the same meaning as described above. ]

［式中、Ｒ¹、Ｒ^ａ２５及びｗ１は、上記と同じ意味を表す。］ The monomer represented by the formula (I′-1) wherein A ¹ in the monomer (I ′) is * —CH ₂ —CO—O— (* represents a bond to —CO—O—) And a compound represented by the formula (I'-1-a) and a compound represented by the formula (I'-1-b) in a solvent. Here, as the solvent, methylene chloride, tetrahydrofuran, acetonitrile and the like are preferably used. The reaction is preferably performed in a temperature range of -5 ° C to 80 ° C for 0.5 to 24 hours.

[Wherein, R ¹ , R ^a25 and w1 represent the same meaning as described above. ]

［式中、Ｒ^１は上記と同じ意味を表す。］
この反応においては、ジシクロヘキシルカルボジイミドなどの縮合触媒を用いることもできる。 The compound represented by the formula (I'-1-a) is obtained by reacting a compound represented by the formula (I'-1-c) with a compound represented by the formula (I'-1-d). Can be obtained. This reaction is preferably performed in the presence of a solvent such as methylene chloride, tetrahydrofuran and acetonitrile.

[Wherein, R ¹ represents the same meaning as described above. ]
In this reaction, a condensation catalyst such as dicyclohexylcarbodiimide can be used.

Examples of the compound represented by the formula (I′-1-c) include the following compounds.

When a compound having A ¹ and R ¹ corresponding to the target compound (I ′) is used as the compound represented by the formula (I′-1-c), the target compound (I ′) can be obtained. . The compounds represented by the formulas (I'-1-c) and (I'-1-d) can be easily obtained from the market.

Examples of the monomer (I ′) include the following monomers and monomers in which the methyl group corresponding to R ¹ in the following monomers has been replaced by a hydrogen atom.

  The content of the structural unit (I) is preferably from 1 to 80 mol%, more preferably from 5 to 75 mol%, even more preferably from 10 to 80 mol%, based on the total of all the structural units of the resin (A1). 70 mol%, particularly preferably 20 to 65 mol%, particularly preferably 45 to 60 mol%.

［式（ａ４−０）中、
Ｒ^５は、水素原子又はメチル基を表す。
Ｌ^５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又は炭素数３〜１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ^６は、水素原子又はフッ素原子を表す。］ <Structural unit (a4-0)>
The resin (A1) has a structural unit (a4-0).

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁵ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the aliphatic saturated hydrocarbon group of L ^5, a methylene group, an ethylene group, propane-1,3-diyl group, a linear alkanediyl group such butane-1,4-diyl group, 1,1 Branched alkanediyl such as diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group A alkanediyl group having 1 to 4 carbon atoms is preferable, a methylene group or an ethylene group is more preferable, and a methylene group is further preferable.

The perfluoro alkanediyl group L ^3, difluoromethylene group, a perfluoroalkyl ethylene group, perfluoroethyl fluoro methylene group, perfluoro-1,3-diyl group, perfluoro-1,2-diyl group, perfluoropropane-2,2 -Diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2 -Diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7 -Diyl group, perfluoroheptane-2 , 2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3 , 3-diyl group, perfluorooctane-4,4-diyl group and the like.
The perfluorocycloalkanes diyl group L ^3, perfluoro cyclopropane-1,3-diyl group, perfluorocyclobutane 2,2-diyl group, a perfluoroalkyl cyclopentane-1,5-diyl group, perfluoro-cyclohexane-1,6 A diyl group and a perfluorocycloadamantyl-1,2-diyl group.

L ⁵ 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 perfluoroalkanediyl group having 1 to 6 carbon atoms or a perfluorocycloalkanediyl group having 3 to 10 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms, and further preferably A perfluoroalkanediyl group having 1 to 2 carbon atoms, particularly preferably a difluoromethylene group.
R ⁶ is preferably a fluorine atom.

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

  The content of the structural unit (a4-0) is preferably 0.5 mol% or more and 9.5 mol% or less, more preferably 0.5 mol% or less, based on the total of all the structural units of the resin (A1). % To 7.5 mol%, more preferably 0.5 mol% to 4.5 mol%, particularly preferably 1 mol% to 4 mol%, particularly preferably 2.5 mol% to 4 mol%. It is not less than 4% by mole and not more than 4% by mole.

  The monomer (a4-0) which derives the structural unit (a4-0) can be easily obtained from the market.

<Structural unit (a1)>
The resin (A1) contains a structural unit (a1) in addition to the structural unit (I) and the structural unit (a4-0).

［式（１）中、Ｒ^ａ１〜Ｒ^ａ３は、互いに独立に、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、又は、Ｒ^ａ１及びＲ^ａ２は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、Ｒ^ａ３は、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。
ｎａは、０又は１を表す。
＊は、結合手を表す。］ The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”).
The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid labile group.
In the resin (A1), the acid labile group contained in the structural unit (a1) is preferably a group represented by the following formula (1) and / or a group represented by the following formula (2).

[In the formula (1), R ^{a1 to} R ^a3 independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof; , R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and R ^a3 is an alkyl group having 1 to 8 carbon atoms and an alicyclic carbon group having 3 to 20 carbon atoms. Represents a hydrogen group or a combination thereof.
na represents 0 or 1.
* Represents a bond. ]

［式（２）中、Ｒ^ａ１’及びＲ^ａ２’は、互いに独立に、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、又は、Ｒ^ａ１’は、水素原子又は炭素数１〜１２の炭化水素基を表し、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 the formula (2), R ^{a1 ′} and R ^{a2 ′} 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 ^{a1 ′} represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a carbon atom having 3 to 3 carbon atoms together with X to which they are bonded; form a divalent heterocyclic group 20, -CH 2 contained in the heterocyclic group of the hydrocarbon group and the divalent _- may be replaced by -O- or -S-.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

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

  Examples of the combination of an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.

When R ^a1 and R ^a2 combine with each other to form a divalent hydrocarbon group, examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) include the following groups, and * represents —O— Represents a bond with The divalent hydrocarbon group preferably has 3 to 12 carbon atoms.

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 an alkyl group in the formula (1), and preferably a tert-butoxycarbonyl group), An alkyl adamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are bonded to each other, form an adamantyl group together with the carbon atom to which they are bonded, and R ^a3 is an alkyl group; Group) and 1- (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), a group in which R ^a1 and R ^a2 are alkyl groups and R ^a3 is an adamantyl group). .

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

At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

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

  Among (meth) acrylic monomers having an acid labile group, (meth) acrylic monomers having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. A resist pattern having a further improved resolution can be formed from a resist composition containing a resin (A1) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group.

［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^ａ０３及びＲ^ａ０４は、互いに独立に、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。］ Preferred examples of the structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1) include a structural unit represented by the formula (a1-0) and a structural unit represented by the formula (a1-1). And a structural unit represented by the formula (a1-2). These may be used alone or in combination of two or more. In the present specification, the structural unit represented by the formula (a1-0), the structural unit represented by the formula (a1-1), and the structural unit represented by the formula (a1-2) are each referred to as a structural unit (a1 -0), structural unit (a1-1) and structural unit (a1-2).

[In the formula (a1-0),
L ^a01 represents an oxygen atom or _{* -O- (CH 2) k01 -CO} -O- the stands, k01 represents an integer of 1-7, * represents a bond to a carbonyl group.
^Ra01 represents a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 independently ^represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof. ]

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^ａ１及びＬ^ａ２は、互いに独立に、−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、互いに独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、互いに独立に、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 the formulas (a1-1) and (a1-2),
L ^a1 and ^{L a2} independently of one another, -O- or _{* -O- (CH 2) k1 -CO} -O- the stands, k1 represents an integer of 1-7, * the binding of -CO- Represent 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 an integer of 0 to 14.
n1 represents the integer of 0-10.
n1 ′ represents an integer of 0 to 3. ]

L ^a02 is preferably an oxygen atom or _{* -O- (CH 2) k01 -CO} -O- , more preferably an oxygen atom. k01 is preferably an integer of 1 to 4, and more preferably 1.
Examples of the alkyl group, alicyclic hydrocarbon group, and a combination thereof of R ^a02 , R ^a03, and R ^a04 include the same groups as those described for R ^{a1 to} R ^a3 in Formula (1).
R ^a02, the number of carbon atoms in the alkyl group of ^{R a03} and ^{R a04} is preferably 6 or less.
The alicyclic hydrocarbon group of ^Ra02 , ^Ra03 and ^Ra04 preferably has 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.
The group obtained by combining the alkyl group and the alicyclic hydrocarbon group preferably has a total carbon number of 18 or less obtained by combining the alkyl group and the alicyclic hydrocarbon group. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
^Ra02 and ^Ra03 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group.
^Ra04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.

L ^a1 and ^{L a2} are preferably -O- or _{* -O- (CH 2) k1 '} -CO-O- , more preferably an is -O-. k1 ′ is an integer of 1 to 4, and is preferably 1.
R ^a4 and R ^a5 are preferably a methyl group.
^Examples of the alkyl group of ^Ra6 and ^Ra7 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 an n-heptyl group, a 2-ethylhexyl group, and an n-octyl group.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. And cycloalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, a norbornyl group, Examples include a methylnorbornyl group and an isobornyl group.
Examples of the group formed by combining the alkyl group of ^Ra6 and ^Ra7 with an alicyclic hydrocarbon group include an aralkyl group, and include a benzyl group and a phenethyl group.
The alkyl group of ^Ra6 and ^Ra7 preferably has 6 or less carbon atoms.
The carbon number of the alicyclic hydrocarbon group of ^Ra6 and ^Ra7 is preferably 3 or more and 8 or less, more preferably 3 or more and 6 or less.
m1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As the structural unit (a1-0), the structural units represented by the formulas (a1-0-1) to (a1-1-12) and the methyl group corresponding to R ^a01 in these structural units is replaced by a hydrogen atom. The substituted structural unit is exemplified, and is preferably a structural unit represented by any one of formulas (a1-0-1) to (a1-1-10).

Examples of the structural unit (a1-1) include monomers described in JP-A-2010-204646. Among them, structural units derived from monomers represented by the following formulas (a1-1-1) to (a1-1-8) are preferable. Structural units derived from the monomers represented are more preferred.

As the structural unit (a1-2), a structural unit derived from a monomer represented by the following formulas (a1-2-1) to (a1-2-12) is preferable. Structural units derived from monomers represented by the formulas (a1-2-4), (a1-2-9) and (a1-2-10) are more preferable, and the formulas (a1-2-3) and (a1-2-3) The structural unit derived from the monomer represented by (a1-2-9) is more preferable.

  When the resin (A1) contains the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is determined by the total structure of the resin (A1). It is usually from 10 to 95 mol%, preferably from 15 to 90 mol%, more preferably from 20 to 85 mol%, based on the total of the units.

［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^ａ１１及びＲ^ａ１２は、互いに独立に、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、又は、Ｒ^ａ１２は、互いに独立に、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し、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２〜２０の２価の炭化水素基を形成する。］ Furthermore, the structural unit (a1) having a group represented by the formula (1) also includes 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). Further, the monomer that derives the structural unit (a1-3) may be referred to as a monomer (a1-3).

[In the formula (a1-3),
^Ra9 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 ^-COORa13 .
^Ra13 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 A 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- Or it may be replaced by -CO-.
R ^a10 , R ^a11 and 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 them; ^{or, R a12} are each independently an alkyl group having 1 to 8 carbon atoms, a group formed by combining the alicyclic hydrocarbon group or those having 3 to 20 carbon ^{atoms, R a10} and ^{R a11} Are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the carbon atoms to which they are bonded. ]

Here, -COOR ^a13 includes 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 which may have a hydroxy group of ^Ra9 include a methyl group, an ethyl group, an n-propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms of ^Ra13 include a methyl group, an ethyl group, and an n-propyl group.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms for Ra13 include cyclopentyl, cyclopropyl, adamantyl, adamantylmethyl, 1-adamantyl-1-methylethyl, and 2-oxo-oxolane-3-. And a 2-oxo-oxolan-4-yl group.
The alkyl group of R ^a10 to R ^a12, methyl, ethyl, n- propyl group, an isopropyl group, n- butyl group, sec- butyl group, tert- butyl group, n- pentyl group, n- hexyl group, Examples include an n-heptyl group, a 2-ethylhexyl group and an n-octyl group.
The alicyclic hydrocarbon group of R ^{a10 to} R ^a12 may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, Cycloalkyl groups such as cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, a norbornyl group, Examples include a methylnorbornyl group and an isobornyl group.
In the case where R ^a10 and R ^a11 are bonded to each other to form a divalent hydrocarbon group together with the carbon atom to which they are bonded, —C (R ^a10 ) (R ^a11 ) (R ^a12 ) is as follows. Groups are preferred.

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

  Since the resin (A1) containing the structural unit (a1-3) contains a three-dimensionally bulky structural unit, the resist composition containing such a resin (A1) can be used as a resist with higher resolution. You can get a pattern. Further, since a rigid norbornane ring is introduced into the main chain, the obtained resist pattern tends to have excellent dry etching resistance.

  When the resin (A1) contains the structural unit (a1-3), its content is preferably from 10 to 95 mol%, preferably from 15 to 90 mol%, based on the total of all the structural units of the resin (A1). %, More preferably 20 to 85 mol%.

［式（ａ１−４）中、
Ｒ^ａ３２は、水素原子、ハロゲン原子、又は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^ａ３３は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、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、互いに独立に、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、又は、Ｒ^ａ３４は、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ３５及びＲ^ａ３６は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｓ−で置き換わってもよい。］ As the structural unit (a1) having a group represented by the group (2), a structural unit represented by the formula (a1-4) (hereinafter, may be referred to as “structural unit (a1-4)”). No.

[In the formula (a1-4),
^Ra32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
^Ra33 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 the integer of 0-4. When la is 2 or more, a plurality of ^Ra33 may be the same or different from each other.
R ^a34 and ^{R a35} are independently of each other, represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon ^atoms, or ^{R a36} represents a hydrocarbon group having 1 to 20 carbon atoms, ^{or, R a34} is hydrogen represents an atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a35 and R ^a36 are bonded together to form a divalent hydrocarbon group having 2 to 20 carbon atoms with each other, the carbonization of the hydrocarbon group and the divalent -CH ₂ contained in the hydrogen radical - may be replaced by -O- or -S-. ]

The alkyl group of R ^a32 and ^{R a33,} methyl, ethyl, n- propyl group, an isopropyl group, n- butyl group, and n- pentyl and n- hexyl group, preferably 1 to 4 carbon atoms And more preferably a methyl group or an ethyl group, and further preferably a methyl group.
Examples of the halogen atom of R ^a32 and ^{R a33,} a fluorine atom, a chlorine atom and a bromine atom.
Examples of the alkyl group which may have a halogen atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, and a 1,1,2,2-tetrafluoro group. Ethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluoro Butyl 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, etc. No.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
Examples of the hydrocarbon group R ^a34 and ^{R a35,} include the same groups as ^{R a1 'and R a2'} of formula (2).
The R ^a36, group formed by combining an alkyl group having 1 to 18 carbon atoms, alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms and these No.

In the formula (a1-4), ^Ra32 is preferably a hydrogen atom.
^Ra33 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.
^Ra34 is preferably a hydrogen atom.
^Ra35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a methyl group or an ethyl group.
The hydrocarbon group of ^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. It is a group formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms.
The alkyl group and the alicyclic hydrocarbon group in ^Ra36 are preferably unsubstituted.
When the aromatic hydrocarbon group for ^Ra36 has a substituent, the substituent is preferably an aryloxy group having 6 to 10 carbon atoms.

  Examples of the monomer that leads to the structural unit (a1-4) include monomers described in JP-A-2010-204646. Above all, monomers represented by formulas (a1-4-1) to (a1-4-8) are preferable, and monomers represented by formulas (a1-4-1) to (a1-4-5) are preferable. More preferred.

  When the resin (A1) has the structural unit (a1-4), its content is preferably from 10 to 95% by mol, based on the total of all the structural units of the resin (A1). Mol%, more preferably 20 to 85 mol%.

［式（ａ１−５）中、
Ｒ^ａ８は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｚ^ａ１は、単結合又は＊−（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^５２、Ｌ^５３及びＬ^５４は、互いに独立に、−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。］ Examples of the structural unit having an acid labile group include a structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”).

[In the formula (a1-5),
^Ra8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or _{* - (CH 2) h3 -CO} -L 54 - represents, h3 represents an integer of 1 to 4, * ^represents a bond to ^{L 51.}
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3. ]

In the formula ^{(a1-5), R a8} represents a hydrogen atom, a methyl group or a trifluoromethyl group.
^L51 is preferably -O-.
One of L ⁵² and ^{L 53} is -O-, and it is preferred the other is -S-.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or _* -CH 2 -CO-O- and which.

Examples of the monomer that leads to the structural unit (a1-5) include monomers described in JP-A-2010-61117. Among them, monomers represented by the formulas (a1-5-1) to (a1-5-4) are preferable, and monomers represented by the formulas (a1-5-1) and (a1-5-2) are preferable. More preferred.

  When the resin (A1) has the structural unit (a1-5), its content is preferably from 1 to 50 mol%, preferably from 3 to 45 mol%, based on the total of all the structural units of the resin (A1). More preferably, it is 5 mol%, more preferably 5 mol% to 40 mol%.

  The structural unit (a) having an acid labile group in the resin (A1) includes a structural unit (a1-0), a structural unit (a1-1), a structural unit (a1-2), and a structural unit (a1-5). Or more preferably at least two or more selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2), the structural unit (a1-1) and the structural unit ( a1-5) combination, structural unit (a1-1) and structural unit (a1-0) combination, structural unit (a1-2) and structural unit (a1-0) combination, structural unit (a1-5) And a combination of structural units (a1-0), a structural unit (a1-0), a combination of structural units (a1-1) and (a1-2), a structural unit (a1-0), and a structural unit (a1- The combination of 1) and the structural unit (a1-5) is more preferred. Even more preferably a combination of structural units (a1-1) and the structural unit (a1-2).

<Structural unit without acid labile group>
The structural unit (s) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). Examples of the monomer (s) include monomers having no acid labile group known in the resist field. Preferred structural units are those having a hydroxy group or a lactone ring and having no acid labile group. Structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or having a lactone ring and having no acid labile group From a resist composition containing a resin having a unit (hereinafter sometimes referred to as a “structural unit (a3)”, but not including a structural unit represented by the formula (I)), resolution and adhesion to a substrate are improved. A more improved resist pattern can be formed.

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

［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。］ Examples of the structural unit (a2) having a phenolic hydroxy group include a structural unit represented by the formula (a2-0) (hereinafter, may be referred to as “structural unit (a2-0)”).

[In the formula (a2-0),
^Ra30 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
^Ra31 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 ^Ra31s may be the same or different. ]

^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom for ^Ra30 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, butyl, perfluoropentyl, 1,1,1,2,2,3,3,4,4-nonafluoropentyl, n-pentyl, n-hexyl Group, n-perfluorohexyl group and the like.
As ^Ra30 , a hydrogen atom or an alkyl group having 1 to 4 carbon atoms is preferable, a hydrogen atom, a methyl group or an ethyl group is more preferable, and a hydrogen atom or a methyl group is further preferable.
^Examples of the alkoxy group of ^Ra31 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group, and an alkoxy group having 1 to 4 carbon atoms is preferable. Preferably, a methoxy group is more preferred.
ma is preferably 0, 1, or 2, more preferably 0 or 1, and even more preferably 0.

Examples of the monomer for deriving the structural unit (a2-0) include monomers described in JP-A-2010-204634.
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 obtained by protecting a phenolic hydroxy group of a monomer for deriving the structural unit (a2-0) with a protecting group, and then deprotected. It can be manufactured by processing. However, when performing the deprotection treatment, it is necessary to perform the deprotection treatment so as not to significantly impair the acid labile group of the structural unit (a1). Examples of such a protecting group include an acetyl group.

  When the resin (A1) has a structural unit (a2-0) having a phenolic hydroxy group, its content is 5 to 95 mol% based on the total of all the structural units of the resin (A1). Is preferably 10 to 80 mol%, more preferably 15 to 80 mol%.

［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、互いに独立に、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。］ Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by the formula (a2-1) (hereinafter, may be referred to as “structural unit (a2-1)”).

[In the formula (a2-1),
L ^a3 is, -O- or _{* -O- (CH 2) k2 -CO} -O- the stands,
k2 represents an integer of 1 to 7. * Represents a bond to -CO-.
^Ra14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10. ]

In the formula ^{(a2-1), L a3} is preferably _{-O -, - O- (CH 2} ) f1 -CO-O- and is (wherein f1 is an integer from 1 to 4), more preferably —O—.
^Ra14 is preferably a methyl group.
^Ra15 is preferably a hydrogen atom.
^Ra16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, and more preferably 0 or 1.

Examples of the monomer for deriving the structural unit (a2-1) include monomers described in JP-A-2010-204646. A monomer represented by any of formulas (a2-1-1) to (a2-1-6) is preferable, and a monomer represented by any of formulas (a2-1-1) to (a2-1-4) is preferable. The monomer represented by the formula (a2-1-1) or the formula (a2-1-3) is more preferable.

  When the resin (A1) contains the structural unit (a2-1), its content is usually from 1 to 45 mol%, preferably from 1 to 40 mol%, based on the total of all the structural units of the resin (A1). %, 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 monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring or a δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. May be. Preferably, a γ-butyrolactone ring or a bridged ring containing 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。］ The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), or the formula (a3-3). One of these may be contained alone, or two or more thereof may be contained.

[In the formula (a3-1),
L ^a4 represents -O- or _{* -O- (CH 2) k3 -CO} -O- (k3 represents. An integer of 1-7) is represented by the group. * Represents a bond to a carbonyl group.
^Ra18 represents a hydrogen atom or a methyl group.
^Ra21 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, a plurality of ^Ra21s may be the same or different.
In the formula (a3-2),
L ^a5 represents -O- or _{* -O- (CH 2) k3 -CO} -O- (k3 represents. An integer of 1-7) is represented by the group. * Represents a bond to a carbonyl group.
^Ra19 represents a hydrogen atom or a methyl group.
^Ra22 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 ^Ra22s may be the same or different.
In the formula (a3-3),
L ^a6 represents -O- or _{* -O- (CH 2) k3 -CO} -O- (k3 represents. An integer of 1-7) is represented by the group. * Represents a bond to a carbonyl group.
^Ra20 represents a hydrogen atom or a methyl group.
^Ra23 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 ^Ra23s may be the same or different from each other. ]

Examples of the aliphatic hydrocarbon group such as ^Ra21 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group.
In the formula (a3-1) ~ formula ^(a3-3), L a4 ^{~L a6,} independently of one another, preferably -O- or, k3 is an integer of from 1 to 4 * -O- _(CH 2) a _k3 -CO-O-group represented by, more preferably -O- _{and, * - O-CH 2 -CO} -O- and, still more preferably an oxygen atom.
^{Ra18 to Ra21} independently of one another are preferably methyl groups.
R ^a22 and R ^a23 independently of one another are 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, and more preferably 0 or 1.

  Examples of the monomer for deriving the structural unit (a3) include a monomer described in JP-A-2010-204646, a monomer described in JP-A-2000-122294, and a monomer described in JP-A-2012-41274. No. Examples of the structural unit (a3) include the formulas (a3-1-1) to (a3-1-6) and the formulas (a3-2-1) to (a3-2-4), and the formula (a3-3-3). Structural units represented by any of 1) to (a3-3-4) are preferable, and formulas (a3-1-1), (a3-1-2) and (a3-2-3) to The structural unit represented by any of the formulas (a3-2-4) is more preferable, and the structural unit represented by the formula (a3-1-1) or the formula (a3-2-3) is further preferable.

When the resin (A1) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on the total of all the structural units of the resin (A1). And more preferably 10 to 60 mol%.
The content of the structural unit (a3-1), the structural unit (a3-2) and the content of the structural unit (a3-3) are, independently of each other, 5 to 5 with respect to the total of all the structural units of the resin (A1). It is preferably 60 mol%, more preferably 5 to 50 mol%, and even more preferably 10 to 50 mol%.

<Other structural units (t)>
As the structural unit (t), a structural unit that may have a fluorine atom in addition to the structural unit (a2) and the structural unit (a3) (hereinafter, sometimes referred to as “structural unit (a4)”; (Excluding (a4-0)) and a structural unit (s) having a non-eliminable hydrocarbon group (hereinafter sometimes referred to as “structural unit (a5)”).

［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。］

［式（ａ−ｇ１）中、
ｓは、０又は１を表す。
Ａ^ａ４２及びＡ^ａ４４は、互いに独立に、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、互いに独立に、−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。］ Examples of the structural unit (a4) include a structural unit represented by the formula (a4-1).

[In the formula (a4-1),
^Ra41 represents a hydrogen atom or a methyl group.
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms that may have a substituent, -CH ₂ contained in the hydrocarbon group - can be replaced by -O- or -CO- Good.
A ^a41 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-g1). ]

[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.
^Aa43 represents a single bond or an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
^Xa41 and ^Xa42 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.
Of the two bonds represented by *, * on the right side is a bond to -O-CO- ^Ra42 . ]

^Examples of the hydrocarbon group of ^Ra42 include linear and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
The linear or cyclic aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is formed by a linear or cyclic aliphatic saturated hydrocarbon group and a combination thereof. Groups are preferred. Examples of the aliphatic saturated hydrocarbon group include a linear or branched alkyl group and a monocyclic or polycyclic alicyclic hydrocarbon group, and a fatty acid formed by combining an alkyl group and an alicyclic hydrocarbon group. Group hydrocarbon group and the like.

Examples of the linear aliphatic hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, and an n-decyl. And n-dodecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl and n-octadecyl. Examples of the cyclic aliphatic hydrocarbon group include a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* And a polycyclic alicyclic hydrocarbon group.

  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.

［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１〜１７の脂肪族炭化水素基を表す。
＊は結合手を表す。］ ^Examples of the substituent for ^Ra42 include a halogen atom and a group represented by the formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a fluorine atom.

[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 1 to 17 carbon atoms and having at least one halogen atom.
* Represents a bond. ]

^Examples of the aliphatic hydrocarbon group for A ^{a45 include} the same groups as those exemplified for R ^a42 .

^Ra42 is preferably an aliphatic hydrocarbon group ^optionally having a halogen atom, and more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (a-g3). .
When ^Ra42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and further preferably the number of carbon atoms is It is a perfluoroalkyl group having 1 to 6, particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.
When ^Ra42 is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), the aliphatic hydrocarbon group includes the number of carbon atoms contained in the group represented by the formula (a-g3). 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 one.

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

[In the formula (a-g2),
^Aa46 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
^Xa44 represents a carbonyloxy group or an oxycarbonyl group.
^Aa47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* Represents a bond to a carbonyl group. ]

The aliphatic hydrocarbon group for ^Aa46 preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms.
The carbon number of the aliphatic hydrocarbon group for A ^a47 is preferably 4 to 15, more preferably 5 to 12, and even more preferably A ^a47 is a cyclohexyl group or an adamantyl group.

The preferred structure represented by * -A ^a46 -X ^a44 -A ^a47 is the following structure.

^Examples of the alkanediyl group for ^Aa41 include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. Linear alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples include a branched alkanediyl group such as a 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.

The aliphatic hydrocarbon group of A ^{a42 to} A ^a44 in the group (a-g1) may have a carbon-carbon unsaturated bond, but is preferably an aliphatic saturated hydrocarbon group. As the aliphatic saturated hydrocarbon group, an alkyl group (the alkyl group may be linear or branched) and an alicyclic hydrocarbon group, and a combination of an alkyl group and an alicyclic hydrocarbon group And the like. Specifically, a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, Examples thereof include a 2-methylpropane-1,3-diyl group and a 2-methylpropane-1,2-diyl group.
^Examples of the substituent of 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 ^Xa42 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- ^Ra42 .

［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), a structural unit represented by the formula (a4-2) and the formula (a4-3) is 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. ]

^Examples of the alkanediyl group for A ^f1 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. Linear alkanediyl groups such as hexane-1,6-diyl group and the like; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 And a branched alkanediyl group such as -diyl group, 1-methylbutane-1,4-diyl group and 2-methylbutane-1,4-diyl group.

The hydrocarbon group for R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain type, a cyclic type, 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, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl and 2 -Ethylhexyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclodecyl group. No. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, a norbornyl group, Examples include a methylnorbornyl group and an isobornyl group.

Examples of the hydrocarbon group having a fluorine atom of 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, , 1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2- Tetrafluoroethyl group, 1- (trifluoromethyl) -2,2,2-trifluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3 1,3-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-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, 2- (perfluoro Butyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5 Examples thereof include a fluorinated alkyl group such as a 6,6-dodecafluorohexyl group, a perfluoropentylmethyl group, and a perfluorohexyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include a cycloalkyl group such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

［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。］ A ^f1 in the formula (a4-2) is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.
R ^f1 is preferably a fluorinated alkyl group having 1 to 6 carbon atoms.

[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 an aliphatic hydrocarbon group having 1 to 18 carbon atoms 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 ^Af13 and ^Af14 represents an aliphatic hydrocarbon group having a fluorine atom. ]

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

The aliphatic hydrocarbon group for ^Af13 includes a linear or cyclic aliphatic hydrocarbon group, and a divalent aliphatic hydrocarbon group formed by combining these. This aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
As the aliphatic hydrocarbon group which may have a fluorine atom of ^Af13 , preferably, an aliphatic saturated hydrocarbon group which may have a fluorine atom is used, and more preferably, a perfluoroalkanediyl group is used. Can be
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 And perfluoroalkanediyl groups such as a perfluoropropanediyl group, a perfluorobutanediyl group and a perfluoropentanediyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be a monocyclic or polycyclic group. 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, and a perfluoroadamantanediyl group.

The aliphatic hydrocarbon group for ^Af14 includes any of a chain type and a cyclic type, and an aliphatic hydrocarbon group formed by combining these. 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 ^Af14 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 trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1 , 2,2-tetrafluoroethyl, ethyl, perfluoropropyl, 1,1,1,2,2-pentafluoropropyl, propyl, perfluorobutyl, 1,1,2,2,3,3 , 4,4-octafluorobutyl, butyl, perfluoropentyl, 1,1,1,2,2,3,3,4,4-nonafluoropentyl, pentyl, hexyl, perfluorohexyl, Examples include a heptyl group, a perfluoroheptyl group, an octyl group and a perfluorooctyl group.
The cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either 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 ^Af13 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.
As the aliphatic hydrocarbon group for ^Af14, an aliphatic hydrocarbon group having 3 to 12 carbon atoms is preferable, and an aliphatic hydrocarbon group having 3 to 10 carbon atoms is more preferable. Among them, ^Af14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group.

Examples of the structural unit represented by the formula (a4-2) include structural units represented by the formulas (a4-1-1) to (a4-1-22).

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

［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、互いに独立に、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) also include a structural unit represented by 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 represent an integer of 1 to 6.
R ^f22 represents a C 1 to ^C 10 hydrocarbon group having a fluorine atom. ]

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

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

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

  When the resin (A1) has the structural unit (a4), its content is preferably from 1 to 20 mol%, more preferably from 2 to 15 mol%, based on the total of all the structural units of the resin (A1). Is more preferable, and it is still more preferable that it is 3 to 10 mol%.

［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^５５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^５５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。］ Examples of the non-eliminated hydrocarbon group contained in the structural unit (a5) include a linear, branched, or cyclic hydrocarbon group. Among them, the structural unit (a5) is preferably a group containing an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1).

[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 having 1 to 8 carbon atoms or a hydroxy group. You may. However, the hydrogen atom bonded to the carbon atom at the coupling position with the L ⁵⁵ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, a methylene group contained in the saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. ]

The alicyclic hydrocarbon group for R ⁵² may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, And alkyl groups such as an octyl group and a 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 of L ⁵¹ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and preferably a divalent aliphatic saturated hydrocarbon group. Can be
Examples of the divalent aliphatic saturated hydrocarbon group include an alkanediyl group 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 a cycloalkanediyl group such as a cyclopentanediyl group and a cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

［式（Ｌ１−１）中、
Ｘ^ｘ１は、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、互いに独立に、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、互いに独立に、単結合又は炭素数１〜１２の２価の脂肪族飽和炭化水素基を表す。
Ｗ^ｘ１は、炭素数３〜１５の２価の脂環式飽和炭化水素基を表す。
ただし、Ｌ^ｘ８、Ｌ^ｘ９及びＷ^ｘ１の合計炭素数は、１５以下である。］ Examples of the group in which the methylene group contained in the saturated hydrocarbon group is replaced by an oxygen atom or a carbonyl group include groups represented by formulas (L1-1) to (L1-4). In the following formula, * represents a bond to an oxygen atom.

[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.
^Lx2 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 the formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
^Lx4 represents a single bond or a divalent saturated aliphatic hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.
In the formula (L1-3),
^Lx5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
^However, the total number of carbon atoms of L x5 ^{~L x7} is 15 or less.
In the formula (L1-4),
^Lx8 and ^Lx9 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of L ^x8 , L ^x9 and W ^x1 is 15 or less. ]

L ^x1 is preferably a divalent saturated aliphatic 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.
^Lx5 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, and more preferably a methylene group or an ethylene group.
^Lx7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
^Lx8 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.
^Lx9 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, more preferably a cyclohexanediyl group or an adamantanediyl group.

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

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

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

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

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

式（ａ５−１−１）〜式（ａ５−１−１８）において、Ｒ^５１に相当するメチル基が水素原子に置き換わった構造単位も、構造単位（ａ５−１）の具体例として挙げることができる。 Examples of the structural unit (a5-1) include the following.

In Formulas (a5-1-1) to (a5-1-18), a structural unit in which a methyl group corresponding to R ⁵¹ is replaced by a hydrogen atom may also be mentioned as a specific example of the structural unit (a5-1). it can.

  When the resin (A1) has the structural unit (a5), its content is preferably from 1 to 30 mol%, more preferably from 2 to 20 mol%, based on the total of all the structural units of the resin (A1). Is more preferable, and it is still more preferable that it is 3 to 15 mol%.

The resin (A1) is preferably a resin composed of the structural unit (I), the structural unit (a4-0), the structural unit (a1), and the structural unit (s), that is, the monomer (I ′) and the monomer (a4). -0), a monomer (a1) and a monomer (s).
The structural unit (a1) is preferably at least one of a structural unit (a1-1) and a structural unit (a1-2) (preferably a structural unit having a cyclohexyl group or a cyclopentyl group), and more preferably a structural unit (a1). a1-1).
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 at least one of the structural unit represented by the formula (a3-1) and the structural unit represented by the formula (a3-2).

  The resin (A1) may contain a structural unit derived from a monomer having an adamantyl group (especially, 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 of the structural units constituting the resin (A1) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, a radical polymerization method) using a monomer that induces these structural units. can do. The content of each structural unit of the resin (A1) can be adjusted by the amount of the monomer used for polymerization.
The weight average molecular weight of the resin (A1) 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, and further preferably 15,000 or less).
In the present specification, the weight average molecular weight is a value determined by gel permeation chromatography. Gel permeation chromatography can be measured under the analysis conditions described in the examples.

<Resin (A2)>
As the resin (A2) containing a structural unit having a fluorine atom and not containing a structural unit having an acid labile group, a resin containing a structural unit (a4-0) or a structural unit (a4) (however, (It does not include the unit (a1) and the structural unit (a4-0).) In the resin (A2), the content of the structural unit (a4-0) or the structural unit (a4) is preferably 40 mol% or more, and more preferably 45 mol%, based on the total of all the structural units of the resin (A2). %, More preferably at least 50 mol%.
Examples of the structural unit that the resin (A2) may further include include a structural unit (a2), a structural unit (a3), a structural unit (a5), and a structural unit known in the art.
The weight average molecular weight of the resin (A2) is preferably 5,000 or more (more preferably 6,000 or more) and 80,000 or less (more preferably 60,000 or less).
When the resist composition of the present invention contains the resin (A2), the content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, based on 100 parts by mass of the resin (A1). Yes, more preferably 2 to 40 parts by mass, particularly preferably 2 to 30 parts by mass.

  The total content of the resin (A1) and the resin (A2) is preferably from 80% by mass to 99% by mass based on the solid content of the resist composition. The solid content of the resist composition and the content of the resin with respect to the solid content can be measured by known analytical means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
The acid generator generates an acid upon exposure, and the generated acid acts as a catalyst to release a group that is released by the acid of the resin (A). The acid generator is classified into a nonionic type and an ionic type, and any of the acid generators (B) in the resist composition of the present invention may be used.
Nonionic acid generators include organic halides, sulfonate esters (eg, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (For example, disulfone, ketosulfone, and sulfonyldiazomethane). Examples of the ionic acid generator include onium salts containing onium cations (eg, 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.

  Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, and JP-A-63-163452. JP-A-62-153853, JP-A-63-14629, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent No. 3,914,407, European Patent No. 126,712. And the like, compounds which generate an acid by radiation described in, for example, can be used. Further, a compound produced by a known method may be used.

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

Examples of the perfluoroalkyl group for 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 perfluoropentyl group. Hexyl group and the like.
Preferably, Q ¹ and Q ² are each independently a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

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 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 Linear groups such as 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 a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, a cyclooctane-1,5-diyl group; Divalent alicyclic saturated hydrocarbon group;
Polycyclic divalent saturated alicyclic hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group And the like.

［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。］ 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) And the group represented by In the formulas (b1-1) to (b1-3) and the following specific examples, * represents a bond to -Y.

[In the formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a 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 hydrocarbon group may be replaced by 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 the formula (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a 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 hydrocarbon group may be replaced by 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 the formula (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a 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 hydrocarbon group may be replaced by 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 the formulas (b1-1) to (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 carbon atoms before the replacement is determined by the carbon number of the saturated hydrocarbon group. Number.
Examples of the divalent saturated hydrocarbon group include the same as the divalent saturated hydrocarbon group for ^Lb1 .

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 a 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 a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a 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 by an oxygen atom or a carbonyl group.

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 a group represented by the formula (b1-1) or (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 the formula (b1-1) include groups represented by formulas (b1-4) to (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 a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In the formula (b1-5),
^Lb9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group .
However, the total carbon number of ^Lb9 and ^Lb10 is 20 or less.
In the formula (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group .
^However, the total number of carbon atoms of ^{L b11} and ^{L b12} is 21 or less.
In the formula (b1-7),
^Lb13 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 a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group .
^However, the total number of carbon atoms of L b13 ^{~L b15} is 19 or less.
In the formula (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
^Lb17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group .
^However, the total number of carbon atoms of L b16 ^{~L b18} is 19 or less. ]

^Lb8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
^Lb9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
^Lb10 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.
^Lb11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
^Lb12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
^Lb13 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.
^Lb15 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.
^Lb16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
^Lb17 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 the formula (b1-3) include groups represented by the formulas (b1-9) to (b1-11).

[In the formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the 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 a hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. Is also good. The methylene group contained in the acyloxy group may be replaced by an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced by a hydroxy group.
^However, the total number of carbon atoms of ^{L b19} and ^{L b20} is 23 or less.
In the formula (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
^Lb22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group, or an acyloxy group. You may. The methylene group contained in the acyloxy group may be replaced by an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced by a hydroxy group.
^However, the total number of carbon atoms of L b21 ^{~L b23} is 21 or less.
In the formula (b1-11),
^Lb24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group of 1 to 21 carbon atoms.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group, or an acyloxy group. You may. The methylene group contained in the acyloxy group may be replaced by an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced by a hydroxy group.
^However, the total number of carbon atoms of L b24 ^{~L b26} is 21 or less. ]

  In the formulas (b1-9) to (b1-11), when the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with an acyloxy group, the number of carbon atoms of the acyloxy group, CO in the ester bond, The number of carbon atoms of the divalent saturated hydrocarbon group is included, including the number of O atoms.

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.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-4) include the following.

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-5) include the following.

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

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

Among the groups represented by the formula (b1-1), the groups represented by the formula (b1-8) include the following.

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

Among the groups represented by the formula (b1-3), the groups represented by the formula (b1-9) include the following.

Among the groups represented by the formula (b1-3), the groups represented by the formula (b1-10) include the following.

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

Examples of the monovalent alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11).
When —CH ₂ — contained in the monovalent alicyclic hydrocarbon group represented by Y is replaced by —O—, —SO ₂ — or —CO—, the number may be one or two or more. There may be more than one. Examples of such a group include groups represented by formulas (Y12) to (Y38).

  That is, in Y, two hydrogen atoms contained in the alicyclic hydrocarbon group are each substituted by an oxygen atom, and the two oxygen atoms form a ketal ring together with an alkanediyl group having 1 to 8 carbon atoms. Or a structure in which oxygen atoms are bonded to different carbon atoms. However, when constituting a spiro ring of the formula (Y28) to the formula (Y33), the alkanediyl group between two oxygens preferably has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, those in which the fluorine atom is not substituted in the methylene group adjacent to the oxygen atom are preferable.

  Among them, a group represented by any of formulas (Y1) to (Y20), formula (Y30), and formula (Y31) is preferable, and more preferable is a group represented by formula (Y11), formula (Y15), and formula (Y16). ), A group represented by the formula (Y20), the formula (Y30) or the formula (Y31), and more preferably a group represented by the formula (Y11), the formula (Y15) or the formula (Y30).

Examples of the substituent of the methyl group represented by Y include a halogen atom, a hydroxy group, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, glycidyloxy group or a _{- (CH 2) ja -O-} CO-R b1 group ^{(wherein, R b1} represents an alkyl group having 1 to 16 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms 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 of the monovalent alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms and an alkyl group having 1 to 12 carbon atoms, and 3 carbon atoms. To 16 monovalent alicyclic hydrocarbon groups, C1 to C12 alkoxy groups, C6 to C18 monovalent aromatic hydrocarbon groups, C7 to C21 aralkyl groups, C2 to C2 4 acyl group, glycidyloxy group or — (CH ₂ ) _ja— O—CO—R ^b1 group (where R ^b1 is an alkyl group having 1 to 16 carbon atoms, a monovalent oil having 3 to 16 carbon atoms) And 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 a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group.
Examples of the monovalent aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group and a p-adamantylphenyl group; a tolyl group, a xylyl group, a cumenyl group and a mesityl group. And aryl groups such as a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group and a 2-methyl-6-ethylphenyl group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group and a naphthylethyl group.
Examples of the 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 a methyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon group at the bonding position with Y -CH ₂ - is preferably replaced by -O- or -CO-. In this case, -CH ₂ contained in the methyl group of Y - 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 by an oxygen atom, a sulfonyl group or a carbonyl group. Y is more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group or a group represented by the following.

  The sulfonate anion in the salt represented by the formula (B1) includes an anion represented by the formula (B1-A-1) to the formula (B1-A-46) [hereinafter referred to as “anion (B1 -A-1) ". Are preferred, and the formulas (B1-A-1) to (B1-A-4), the formula (B1-A-9), the formula (B1-A-10), and the formulas (B1-A-24) to (B1-A-33), and anions represented by any of formulas (B1-A-36) to (B1-A-40) are 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 above.
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include anions described in JP-A-2010-204646.

Preferable examples of the sulfonate anion in the salt represented by the formula (B1) include anions represented by the formulas (B1a-1) to (B1a-22).

  Among them, the formulas (B1a-1) to (B1a-3) and the formulas (B1a-7) to (B1a-16), the formula (B1a-18), the formula (B1a-19), and the formula (B1a-22) An anion represented by any of the above is preferred.

［式（ｂ２−１）〜式（ｂ２−４）において、
Ｒ^ｂ４〜Ｒ^ｂ６は、互いに独立に、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、互いに独立に、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、互いに独立に、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、互いに独立に、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基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、互いに独立に、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、互いに独立に、０〜５の整数を表す。
ｑ２及びｒ２は、互いに独立に、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。］ Examples of the organic cation of Z ⁺ include an organic onium cation, for example, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, an organic phosphonium cation, and the like, preferably an organic sulfonium cation or an organic iodonium cation. And more preferably an arylsulfonium cation.
Z ⁺ in the formula (B1) is preferably a cation represented by any of the formulas (b2-1) to (b2-4) [hereinafter, “cation (b2-1)” according to the formula number, and the like. There is a case. ].

[In the formulas (b2-1) to (b2-4),
R ^{b4 to} R ^b6 each independently represent 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 having 6 to 36 carbon atoms. A 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 atom having 3 to 12 carbon atoms. It may be substituted by 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, a carbon atom having 1 to 18 carbon atoms. May be substituted with a monovalent aliphatic hydrocarbon group, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, and a hydrogen atom contained in the monovalent aromatic hydrocarbon group may be a halogen atom, It may be substituted with a group or an alkoxy group having 1 to 12 carbon atoms.
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, a plurality of R ^b7 may be the same or different, and when n2 is 2 or more, a 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 hydrocarbon 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 group may be substituted with a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. The contained hydrogen atom may be substituted by 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 be taken together to form a ring containing —CH—CO— to which they are attached, and —CH ₂ — contained in the ring is —O—, —SO— Or 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.
^Lb31 represents -S- or -O-.
o2, p2, s2 and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4;
u2 represents 0 or 1.
When o2 is 2 or more, a plurality of R ^b13 may be the same or different. When p2 is 2 or more, a plurality of R ^b14 may be the same or different. When q2 is 2 or more. , A plurality of R ^b15 may be the same or different, and when r2 is 2 or more, a plurality of R ^b16 may be the same or different, and when s2 is 2 or more, a plurality of R ^b17 When t2 is 2 or more, a plurality of R ^b18 may be the same or different. ]

Examples of the monovalent aliphatic hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl and octyl. -An alkyl group of an ethylhexyl group. Among them, the monovalent aliphatic hydrocarbon group of R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The monovalent alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic monovalent alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclopentyl group. Examples thereof include a cycloalkyl group such as a hexyl 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.

Among them, 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, a methylnorbornyl group Group, isobornyl group and the like. In a monovalent alicyclic hydrocarbon group in which a hydrogen atom is substituted by 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, tolyl, xylyl, cumenyl, mesityl, p-ethylphenyl, p-tert-butylphenyl, p-cyclohexylphenyl, p- And 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 aromatic hydrocarbon group may have 1 to 18 carbon atoms or a monovalent aliphatic hydrocarbon group. Preferred are monovalent alicyclic hydrocarbon groups of formulas 3 to 18.
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 benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, and naphthylethyl group. .

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group.
Examples of the 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 include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

The ring which R ^b4 and R ^b5 may form together with the sulfur atom to which they are bonded may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. There may be. The ring includes a ring having 3 to 18 carbon atoms, and preferably a ring having 4 to 18 carbon atoms. Further, as the ring containing a sulfur atom, a 3- to 12-membered ring is exemplified, preferably a 3- to 7-membered ring, and specifically, the following rings are exemplified.

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, for example, a thiolan-1-ium ring (tetrahydrothiophenium ring) and a thian-1-ium ring. And a 1,4-oxathiane-4-ium ring.
The ring formed by R ^b11 and R ^b12 together may be any of a monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated ring. Examples of the ring include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, such as an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring. Can be

  Among cations (b2-1) to cations (b2-4), cations (b2-1) are preferred.

Examples of the cation (b2-1) include the following cations.

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

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

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

  The acid generator (B1) is a combination of the above-mentioned sulfonic acid anion and the above-mentioned organic cation, and these can be arbitrarily combined. The acid generator (B1) is preferably represented by any one of the formulas (B1a-1) to (B1a-3) and the formulas (B1a-7) to (B1a-19) and the formula (B1a-22). And a combination of the anion and the cation (b2-1) or the cation (b2-3).

Preferred examples of the acid generator (B1) include those represented by formulas (B1-1) to (B1-40). Among them, formula (B1-1) containing an arylsulfonium cation, and formula (B1) -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 (B1-17), Formula (B1-20), Formula (B1-21), Formula (B1-23), Formula (B1-24), Formula (B1-25) ), Formula (B1-26), Formula (B1-29), Formula (B1-31), Formula (B1-32), Formula (B1-33), Formula (B1-34), Formula (B1-35) , Formula (B1-36), Formula (B1-37), Formula (B1-38), Formula (B1-39) or Formula (B1-40) Preferred.

The content of the acid generator (B1) is preferably from 30% by mass to 100% by mass, more preferably from 50% by mass to 100% by mass, based on the total amount of the acid generator (B). More preferably, it is substantially only the acid generator (B1).
The content of the acid generator (B) is preferably at least 1 part by mass (more preferably at least 3 parts by mass), preferably at most 30 parts by mass (more preferably at least 25 parts by mass) based on 100 parts by mass of the resin (A). Part below). The resist composition of the present invention may contain one kind of acid generator (B), or may contain plural kinds.

<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 of the solvent (E) can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; Esters; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; and cyclic esters such as γ-butyrolactone. The solvent (E) may contain one type alone, or may contain two or more types.

<Quencher (C)>
Examples of the quencher (C) include a basic nitrogen-containing organic compound and a salt that generates an acid having a lower acidity than the acid generated from the acid generator (B).
Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Amines include aliphatic amines and aromatic amines. Aliphatic amines include primary, secondary 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, trihexylamine 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 No. 2575, a hindered amine compound having a piperidine skeleton, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ) Ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) Ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipicolylamine, bipyridine and the like, and preferred. Is diisopropylaniline, more preferably 2,6-diisopropylaniline.

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

Examples of the salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) include a salt represented by the following formula, a weak acid inner salt represented by the formula (D), and JP-A-2012-2012. 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 of a salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) is represented by an acid dissociation constant (pKa). A 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 generated from the salt has an acid dissociation constant of usually −3 <pKa, The salt is preferably a salt of -1 <pKa <7, and more preferably a salt of 0 <pKa <5.

［式（Ｄ）中、
Ｒ^Ｄ１及びＲ^Ｄ２は、互いに独立に、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、互いに独立に、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 each independently represent 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. , An alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group or a halogen atom.
m ′ and n ′ each independently represent an integer of 0 to 4; when m ′ is 2 or more, a plurality of ^RD1s may be the same or different; when n ′ is 2 or more, A plurality of ^RD2s 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 Groups formed by combining these are exemplified.
Examples of the monovalent aliphatic hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, and a nonyl group.
The monovalent alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be saturated or unsaturated. For example, a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclononyl group, a cyclododecyl group, a norbornyl group, an adamantyl group and the like can be mentioned.
Examples of the monovalent aromatic hydrocarbon group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-ethylphenyl group. Propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-tert-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group And aryl groups such as a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group and a 2-methyl-6-ethylphenyl group.
Examples of the group formed by combining these include an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, and 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) and the like.

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 above 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 each independently represent an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 2 to 2 carbon atoms. 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 is preferable.
m ′ and n ′ are preferably each independently an integer of 0 to 2, and more preferably 0. When m 'is 2 or more, a plurality of ^RD1s may be the same or different, and when n' is 2 or more, a plurality of ^RD2s 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) in the solid content of the resist composition is preferably 0.01 to 5% by mass, more preferably 0.01 to 4% by mass, and still more preferably 0.01 to 3% by mass. %.

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

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A1) and an acid generator (B), and optionally a resin (A2), a solvent (E), a quencher (C) and other components (F). Can be prepared by mixing The mixing order is arbitrary and is not particularly limited. An appropriate temperature can be selected from 10 to 40 ° C. depending on the type of the resin and the like and the solubility of the resin and the like in the solvent (E). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to perform filtration using a filter having a pore size of about 0.003 to 0.2 μm.

[Resist pattern manufacturing method]
The method for producing a resist pattern according to the present invention includes:
(1) a step of applying the resist composition of the present invention on a substrate,
(2) drying the composition after application to form 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 application of the resist composition onto the substrate can be performed 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 application, the solvent is removed to form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called prebaking), or using a decompression device. The heating temperature is preferably, for example, 50 to 200 ° C., and the heating time is preferably, for example, 10 to 180 seconds. The pressure at the time of drying under reduced pressure is preferably about 1 to 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. Various light sources can be used as the exposure light source, but an ArF excimer laser (wavelength 193 nm) is preferable. At the time of exposure, the exposure is usually performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.

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

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

As the developing solution, a developing solution containing an organic solvent (hereinafter sometimes referred to as “organic developing solution”) is preferable. By using an organic developer, a negative resist pattern can be produced from the resist composition of the present invention.
Examples of the organic solvent contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether. Ether solvents; amide solvents such as N, N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole.
The content of the organic solvent in the organic developer is preferably from 90% by mass to 100% by mass, more preferably from 95% by mass to 100% by mass, and substantially only the organic solvent. Is more preferable.
Among them, as the organic developer, a developer containing butyl acetate and / or 2-heptanone is preferable. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially More preferably, it is only butyl acetate and / or 2-heptanone.
The organic developer may contain a surfactant. Further, 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 type different 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 preferably, an alcohol solvent or an ester solvent is used.
After the cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the pattern.

[Application]
The resist composition of the present invention is suitable as 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. Yes, it is more suitable as a resist composition for electron beam (EB) exposure, a resist composition for ArF excimer laser exposure, or a resist composition for EUV exposure, and more suitable as a resist composition for ArF excimer laser exposure. Yes, it is useful for semiconductor fine processing.

The present invention will be described more specifically with reference to examples. In the examples, "%" and "part" representing the content or the use amount 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 (Tosoh Corporation)
Eluent: tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μL
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

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

特開２００８−２０９９１７号公報に記載された方法によって得られた式（Ｂ１−２１−ｂ）で表される化合物３０．００部、式（Ｂ１−２１−ａ）で表される塩３５．５０部、クロロホルム１００部及びイオン交換水５０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、このクロロホルム層にイオン交換水３０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１００部を加えて２３℃で３０分間攪拌し、ろ過することにより、式（Ｂ１−２１−ｃ）で表される塩４８．５７部を得た。 Synthesis Example 1 [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 represented by the formula (B1-21-a) 35.50 , 100 parts of chloroform and 50 parts of ion-exchanged water, and the mixture was stirred at 23 ° C for 15 hours. Since the obtained reaction solution was separated into two layers, the chloroform layer was separated and taken out. Further, 30 parts of ion-exchanged water was added to the chloroform layer, followed by washing with water. This operation was repeated five times. The chloroform layer was concentrated, 100 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23 ° C. for 30 minutes, and filtered to obtain a salt represented by the formula (B1-2-1-c). 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部を添加した後、更に、１００℃で１時間攪拌した。得られた反応溶液を濃縮した。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た。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 the salt represented by the formula (B1-21-c), 2.84 parts of the compound represented by the formula (B1-21-d), and 250 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . After adding 0.21 part of copper (II) dibenzoate to the obtained liquid mixture, it further stirred at 100 degreeC for 1 hour. The obtained reaction solution was concentrated. To the obtained residue, 200 parts of chloroform and 50 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and an organic layer was taken out. 50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. This washing operation was repeated five times. The obtained organic layer was concentrated. The resulting residue was dissolved in 53.51 parts of acetonitrile, concentrated, and 113.05 parts of tert-butyl methyl ether was added thereto, followed by stirring and filtration to obtain a salt represented by the formula (B1-21). 10.47 parts were obtained.

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、この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 2 [Synthesis of salt represented by formula (B1-22)]

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

  11.71 parts of the salt represented by the formula (B1-22-c), 1.70 parts of the compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene are charged, and the mixture is heated at 23 ° C. for 30 minutes. Stirred. 0.12 parts of copper (II) dibenzoate was added to the obtained mixture, and the mixture was further stirred at 100 ° C. for 30 minutes. The obtained reaction solution was concentrated. To the obtained residue, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C. for 30 minutes. 12.50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. This washing operation was repeated eight times. The obtained organic layer was concentrated. To the obtained residue, tert-butyl methyl ether (50 parts) was added, stirred, and filtered to obtain 6.84 parts of a salt represented by the formula (B1-22).

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

以下、これらのモノマーを式番号に応じて「モノマー（ａ１−１−１）」等という。 Synthesis of Resin The compounds (monomers) used in the synthesis of the resin are shown below.

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

Synthesis Example 3 [Synthesis of Resin A1-1]
As monomers, monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-1), monomer (a3-4-2) and monomer (a4-0-3) were used, The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-1): monomer (a3-4-2): monomer (a4-0-3)] is The mixture was mixed at 18.5: 18.5: 5.5: 55: 2.5, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of the monomers was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a mixed solvent of methanol / water and filtered to obtain a resin A1-1 having a weight average molecular weight of 7.8 × 10 ^{3 in} a yield of 68%. This resin A1-1 has the following structural units.

Synthesis Example 4 [Synthesis of Resin A1-2]
As monomers, monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-1), monomer (a3-4-2) and monomer (a4-0-3) were used, The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-1): monomer (a3-4-2): monomer (a4-0-3)] is The mixture was mixed at 18.5: 18.5: 4.5: 54: 4.5, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total monomer amount was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin A1-2 having a weight average molecular weight of 7.8 × 10 ^{3 in} a yield of 70%. This resin A1-2 has the following structural units.

Synthesis Example 5 [Synthesis of Resin A1-3]
As monomers, monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-1), monomer (a3-4-2) and monomer (a4-0-3) were used, The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-1): monomer (a3-4-2): monomer (a4-0-3)] is 20: 20: 4.5: 48: 7.5, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of monomers was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin A1-3 having a weight average molecular weight of 7.8 × 10 ^{3 in} a yield of 66%. This resin A1-3 has the following structural units.

Synthesis Example 6 [Synthesis of Resin A1-4]
As monomers, monomer (a1-1-3), monomer (a1-2-9), monomer (a3-2-1), monomer (a3-4-2) and monomer (a4-0-3) were used, The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a3-2-1): monomer (a3-4-2): monomer (a4-0-3)] is The mixture was mixed at 18.5: 18.5: 10: 50: 3, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total monomer amount was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a mixed solvent of methanol / water and filtered to obtain a resin A1-4 having a weight average molecular weight of 6.9 × 10 ^{3 in} a yield of 70%. This resin A1-4 has the following structural units.

Synthesis Example 7 [Synthesis of Resin A1-5]
A monomer (a1-1-2), a monomer (a3-4-2) and a monomer (a4-0-3) are used as monomers, and the molar ratio thereof is [monomer (a1-1-2): monomer (a3-4)]. -2): Monomer (a4-0-3)] was mixed so as to be 40: 55: 5, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total monomer amount was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin A1-5 having a weight average molecular weight of 7.9 × 10 ^{3 in} a yield of 70%. This resin A1-5 has the following structural units.

Synthesis Example 8 [Synthesis of Resin A1-6]
As the monomer, a monomer (a1-1-1), a monomer (a2-1-x), a monomer (a3-4-2) and a monomer (a4-0-3) were used, and the molar ratio thereof was [monomer (a1-1) -1): Monomer (a2-1-x): Monomer (a3-4-2): Monomer (a4-0-3)] is mixed at 35: 5: 55: 5, and the total monomer amount 1.5 mass times of propylene glycol monomethyl ether acetate was added to obtain a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a mixed solvent of methanol / water and filtered to obtain a resin A1-7 having a weight average molecular weight of 7.5 × 10 ^{3 in} a yield of 64%. This resin A1-7 has the following structural units.

Synthesis Example 9 [Synthesis of Resin A1-7]
As monomers, monomer (a1-1-3), monomer (a1-2-11), monomer (a2-1-1), monomer (a3-4-2) and monomer (a4-0-3) were used, The molar ratio [monomer (a1-1-3): monomer (a1-2-11): monomer (a2-1-1): monomer (a3-4-2): monomer (a4-0-3)] is The mixture was mixed at 18.5: 18.5: 5.5: 55: 2.5, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of the monomers was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin A1-7 having a weight average molecular weight of 7.7 × 10 ^{3 in} a yield of 64%. This resin A1-7 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A1-8]
As monomers, monomer (a1-1-3), monomer (a1-2-11), monomer (a2-1-1), monomer (a3-4-2) and monomer (a4-0-19) were used. The molar ratio [monomer (a1-1-3): monomer (a1-2-11): monomer (a2-1-1): monomer (a3-4-2): monomer (a4-0-19)] is The mixture was mixed at 18.5: 18.5: 5.5: 55: 2.5, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of the monomers was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin A1-8 having a weight average molecular weight of 8.9 × 10 ^{3 in} a yield of 60%. This resin A1-8 has the following structural units.

Synthesis Example 11 [Synthesis of Resin A1-9]
As monomers, monomer (a1-1-3), monomer (a1-2-11), monomer (a2-1-1), monomer (a3-4-2) and monomer (a4-0-34) were used, The molar ratio [monomer (a1-1-3): monomer (a1-2-11): monomer (a2-1-1): monomer (a3-4-2): monomer (a4-0-34)] is The mixture was mixed at 18.5: 18.5: 5.5: 55: 2.5, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of the monomers was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a mixed solvent of methanol / water and filtered to obtain a resin A1-9 having a weight average molecular weight of 7.8 × 10 ^{3 in} a yield of 63%. This resin A1-9 has the following structural units.

Synthesis Example 12 [Synthesis of Resin A1-10]
As monomers, monomer (a1-1-3), monomer (a1-2-11), monomer (a3-2-1), monomer (a3-4-2) and monomer (a4-0-3) were used, The molar ratio [monomer (a1-1-3): monomer (a1-2-11): monomer (a3-2-1): monomer (a3-4-2): monomer (a4-0-3)] is The mixture was mixed at 18.5: 18.5: 10: 50: 3, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total monomer amount was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a mixed solvent of methanol / water and filtered to obtain a resin A1-10 having a weight average molecular weight of 7.6 × 10 ^{3 in} a yield of 65%. This resin A1-10 has the following structural units.

Synthesis Example 13 [Synthesis of Resin A1-11]
As monomers, monomer (a1-1-3), monomer (a1-2-11), monomer (a3-2-1), monomer (a3-4-2) and monomer (a4-0-19) were used, The molar ratio [monomer (a1-1-3): monomer (a1-2-11): monomer (a3-2-1): monomer (a3-4-2): monomer (a4-0-19)] is The mixture was mixed at 18.5: 18.5: 10: 50: 3, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total monomer amount was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin A1-11 having a weight average molecular weight of 8.9 × 10 ^{3 in} a yield of 62%. This resin A1-11 has the following structural units.

Synthesis Example 14 [Synthesis of Resin A1-12]
As monomers, monomer (a1-1-3), monomer (a1-2-11), monomer (a3-2-1), monomer (a3-4-2) and monomer (a4-0-34) were used, The molar ratio [monomer (a1-1-3): monomer (a1-2-11): monomer (a3-2-1): monomer (a3-4-2): monomer (a4-0-34)] is The mixture was mixed at 18.5: 18.5: 10: 50: 3, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total monomer amount was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a mixed solvent of methanol / water and filtered to obtain a resin A1-12 having a weight average molecular weight of 8.0 × 10 ^{3 in} a yield of 66%. This resin A1-12 has the following structural units.

Synthesis Example 15 [Synthesis of Resin A2-1]
Monomers (a5-1-1) and (a4-0-12) were used as monomers, and the molar ratio (monomer (a5-1-1): monomer (a4-0-12)) was 50:50. And mixed to obtain a solution by adding 0.6% by mass of methyl isobutyl ketone to the total amount of monomers. To this solution, azobis (2,4-dimethylvaleronitrile) as an initiator was added at 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and this resin was filtered to obtain a resin A2-1 having a weight average molecular weight of 1.5 × 10 ^{4 in} a yield of 88%. . This resin A2-1 has the following structural units.

Synthesis Example 16 [Synthesis of Resin X1]
A monomer (a1-1-2), a monomer (a3-2-1) and a monomer (a4-0-3) are used as monomers, and the molar ratio thereof is [monomer (a1-1-2): monomer (a3-2)]. -1): Monomer (a4-0-3)] was mixed so as to be 40:20:40, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of monomers was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin X1 having a weight average molecular weight of 7.3 × 10 ^{3 in} a yield of 65%. This resin X1 has the following structural units.

Synthesis Example 17 [Synthesis of Resin X2]
A monomer (a1-1-1), a monomer (a2-1-x) and a monomer (a4-0-3) are used as monomers, and the molar ratio thereof is [monomer (a1-1-1): monomer (a2-1)]. -X): Monomer (a4-0-3)] was mixed at 30:30:40, and propylene glycol monomethyl ether acetate 1.5 times by mass of the total amount of monomers was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators to this solution, based on the total amount of monomers, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a mixed solvent of methanol / water to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin X2 having a weight average molecular weight of 7.0 × 10 ^{3 in} a yield of 67%. This resin X2 has the following structural units.

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

＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ２６５部
プロピレングリコールモノメチルエーテル ２０部
２−ヘプタノン ２０部
γ−ブチロラクトン ３．５部 <Resin>
A1-1 to A1-12, A2-1, X1 to X3: Resin A1-1 to Resin A1-12, Resin A2-1, Resin X1 to Resin X3
<Acid generator>
B1-21: Salt represented by the formula (B1-21) B1-22: Salt represented by the formula (B1-22) <Compound (D)>
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

<Residue evaluation>
A composition for an organic anti-reflection film [ARC-29; manufactured by Nissan Chemical Co., Ltd.] is applied on a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain an organic material having a thickness of 78 nm. An anti-reflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the composition layer after drying (prebaking) had a thickness of 85 nm. The silicon wafer coated with the resist composition was pre-baked on a direct hot plate at a temperature described in the “PB” column of Table 1 for 60 seconds to form a composition layer on the silicon wafer. An ArF excimer laser stepper for liquid immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, Dipole 0.900 / 0.700 Y-pol.] Was formed on the composition layer formed on the silicon wafer. Illumination], exposure was performed using a mask for forming a trench pattern (pitch: 120 nm / trench: 40 nm) while changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium. After the exposure, post-exposure baking was performed on a hot plate at a temperature described in the “PEB” column of Table 1 for 60 seconds. Next, the composition layer after heating was developed by a dynamic dispense method at 23 ° C. for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developer to produce a negative resist pattern. .

  In the obtained resist pattern, the exposure amount at which the line width of the trench pattern became 40 nm was defined as the effective sensitivity.

  The trench pattern manufactured at the effective sensitivity was observed with a scanning electron microscope. Observation was made on the substrate dissolved in the unexposed portion of the developing solution, and the case where no residue was observed was evaluated as ○, and the case where residue was observed was evaluated as x. Table 2 shows the results.

<Line edge roughness evaluation (LER)>
A composition for an organic anti-reflection film [ARC-29; manufactured by Nissan Chemical Co., Ltd.] is applied on a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain an organic material having a thickness of 78 nm. An anti-reflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the composition layer after drying (prebaking) had a thickness of 100 nm. After the application, 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 on the silicon wafer.
An ArF excimer laser stepper for liquid immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, Annular σ _out = 0.85 σ _in = 0.65 XY−] is formed on the composition layer formed on the silicon wafer. pol. Illumination], exposure was performed using a mask for forming a trench pattern (pitch: 120 nm / trench width: 40 nm) while changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed on a hot plate at a temperature described in the “PEB” column of Table 1 for 60 seconds. Then, the composition layer on the silicon wafer is developed by a dynamic dispense method at 23 ° C. for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution to form a negative resist pattern. Manufactured.

  In the obtained resist pattern, the exposure amount at which the width of the trench pattern became 40 nm was defined as the effective sensitivity.

With respect to the obtained resist pattern, the width of unevenness of the wall surface was observed and measured by a scanning electron microscope. This swing width
Those having a size of 3 nm or less were evaluated as having a good LER.
Those having a size exceeding 3 nm were evaluated as having poor LER, and were evaluated as x. Table 2 shows the results. The numerical value in parentheses indicates the runout width (nm).

  From the above results, it can be seen that, according to the resist composition of the present invention, no residue is generated and a resist pattern can be manufactured with good line edge roughness (LER).

  The resist composition of the present invention is suitable for fine processing of semiconductors because no residue is generated in the obtained resist pattern and the resist pattern can be manufactured with good line edge roughness (LER).

Claims (9)

A resist composition comprising a resin (A1) containing a structural unit represented by the formula (I), a structural unit represented by the formula (a4-0) and a structural unit having an acid labile group, and an acid generator.

[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ^{1 is, * - A 2 -O -,} * - A 2 -CO-O -, * - A 2 -CO-O-A 3 -CO-O- or ^{* -A 2 -O-CO-A} 3 Represents -O-.
* Represents a bond to -O-.
A ² and A ³ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
^Ra25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
w1 represents an integer of 0 to 8. When w1 is 2 or more, a plurality of ^Ra25s may be the same or different. ]

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁵ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ] L ³ is, the resist composition of claim 1 wherein the perfluoro alkanediyl group having 1 to 2 carbon atoms. 3. The resist composition according to claim 1, wherein R ⁶ is a fluorine atom.   The content of the structural unit represented by the formula (a4-0) is 0.5 mol% or more and 9.5 mol% or less based on the total of all the structural units of the resin (A1). The resist composition according to any one of the above. The resist composition according to any one of claims 1 to 4, wherein the structural unit having an acid labile group has a structural unit represented by the formula (a1-1) or a structural unit represented by the formula (a1-2). .

[In the formulas (a1-1) and (a1-2),
L ^a1 and ^{L a2} independently of one another, -O- or _{* -O- (CH 2) k1 -CO} -O- the stands, k1 represents an integer of 1-7, * the binding of -CO- Represent hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents an integer of 0 to 14.
n1 represents the integer of 0-10.
n1 ′ represents an integer of 0 to 3. ] The resist composition according to any one of claims 1 to 5, wherein the acid generator is a salt represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, wherein the alkyl group and the monovalent it is, -O - - -CH ₂ contained in the alicyclic hydrocarbon group, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]   The resist composition according to any one of claims 1 to 6, further comprising a salt that generates an acid having a lower acidity than the acid generated from the acid generator.   The resist composition according to any one of claims 1 to 7, wherein the resist composition further contains a resin (A2) containing a structural unit having a fluorine atom and not containing a structural unit having an acid labile group. (1) a step of applying the resist composition according to any one of claims 1 to 8 onto a substrate;
(2) drying the composition after application to form 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,
A method for producing a resist pattern comprising: