JP2013041257A - Resist composition and production method of resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition from which a resist pattern having more preferable line edge roughness (LER) can be produced.SOLUTION: The resist composition comprises: a resin (A) having an acid decomposable group; a salt (B) expressed by the formula (B4) and a salt (E1) expressed by the formula (E1). In formula (B4), Arepresents an organic cation having neither acid decomposable group nor nitrogen atom, and Xrepresents an organic sulfonic acid anion having an acid decomposable group and no nitrogen atom. In formula (E1), Arepresents an organic cation having a nitrogen atom, and Xrepresents an organic sulfonic acid anion having no nitrogen atom.

Description

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

  As a microfabrication technique for semiconductors, an optical lithography technique using short-wavelength light such as an ArF excimer laser (wavelength: 193 nm) as an exposure source has been studied. The resist composition used in such a photolithographic technique usually contains a resin having an acid-decomposable group, an acid generator, and a solvent. In recent years, an acid generator having an acid-decomposable group similar to that of the resin and a resist composition containing the acid generator have been developed.

で表される塩と、
メタクリル酸２−エチル−２−アダマンチル、メタクリル酸３−ヒドロキシ−１−アダマンチル及びα−メタクリロイロキシ−γ−ブチロラクトンから製造される樹脂と、
２，６−ジイソプロピルアニリンとからなるレジスト組成物が記載されている。 As such a resist composition, for example, Patent Document 1 discloses the following:

A salt represented by
A resin produced from 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate and α-methacryloyloxy-γ-butyrolactone;
A resist composition comprising 2,6-diisopropylaniline is described.

JP 2008-69146 A

  As the design dimensions of semiconductor microfabrication become increasingly finer, it is required to produce a resist pattern with better line edge roughness (LER). In producing a resist pattern having such line edge roughness (LER), the resist composition described in Patent Document 1 still has room for improvement.

［式（Ｂ４）中、
Ａ^＋は、酸分解性基及び窒素原子を有さない有機カチオンを表す。
Ｘ_ａ ⁻は、酸分解性基を有し、窒素原子を有さない有機スルホン酸アニオンを表す。］
で表される塩（Ｂ）と、
式（Ｅ１）

［式（Ｅ１）中、
Ａ_Ｎは窒素原子を有する有機カチオンを表す。
Ｘ⁻は、窒素原子を有さない有機スルホン酸アニオンを表す。］
で表される塩（Ｅ１）と
を含有するレジスト組成物。
〔２〕 前記式（Ｂ４）のＡ^＋が、酸分解性基及び窒素原子を有さない有機スルホニウムカチオンであり、前記式（Ｅ１）のＡ_Ｎ ^＋が、窒素原子を有する有機スルホニウムカチオンである〔１〕記載のレジスト組成物。
〔３〕 前記式（Ｂ４）のＸ_ａ ⁻が、式（ｂ４−１）又は（ｂ４−２）で表される有機スルホン酸アニオンである〔１〕又は〔２〕記載のレジスト組成物。

［式（ｂ４−１）中、
Ｘ^ｂ１は窒素原子を有さない酸分解性基を表す。
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、窒素原子を有さない２価の連結基を表す。］

［式（ｂ４−２）中、
Ｘ^ｂは、窒素原子を有さない酸分解性基を表す。
ｍ４は１又は２の整数を表し、ｍ４が２であるとき、２つ存在するＸ^ｂは同一又は相異なる。］
〔４〕 式（ｂ４−１）で表される有機スルホン酸アニオンが、式（ｂ４−１−Ａ）で表される有機スルホン酸アニオンである〔３〕記載のレジスト組成物。

［式（ｂ４−１−Ａ）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1''及びＬ^ｂ１'は、それぞれ独立して、単結合又は炭素数１〜１７の２価の脂肪族炭化水素基を表し、該２価の脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙ^ｂ１は、炭素数１〜５のアルキル基を有していてもよいフェニレン基又は単結合を表す。
Ｘ^ｂは、窒素原子を有さない酸分解性基を表す。］
〔５〕 前記式（Ｅ１）のＡ_Ｎ ^＋が、式（ｅ１−１）、式（ｅ１−２）及び式（ｅ１−３）のいずれかで表される有機カチオンである〔１〕〜〔４〕のいずれか記載のレジスト組成物。

［式（ｅ１−１）中、
Ｒ^ｅ１及びＲ^ｅ２はそれぞれ独立に、水素原子、ハロゲン原子、ヒドロキシ基、シアノ基、炭素数１〜１０のアルキル基、炭素数１〜４のアルコキシ基又は炭素数２〜５のアシル基を表す。
式（ｅ１−２）中、
Ｒ^ｅ３は、ヒドロキシ基又は炭素数１〜１２のアルキル基を表し、該アルキル基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｒ^ｅ４及びＲ^ｅ６は、それぞれ独立に、水素原子又は炭素数１〜６のアルキル基を表す。
ｍ７は、０〜３の整数を表す。ｍ８及びｍ９はそれぞれ独立に、１又は２を表す。
ｍ７が２又は３であるとき、複数存在するＲ^ｅ3は同一又は相異なる。
ｍ８が２であるとき、２つ存在するＲ^ｅ４は同一又は相異なる。
ｍ９が２であるとき、２つ存在するＲ^ｅ６は同一又は相異なる。
Ｒ^ｅ５は、水素原子又は炭素数１〜１２のアルキル基を表し、該アルキル基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ｍ１０は、０又は１を表す。］
式（ｅ１−３）中、
Ｒ^ｅ７、Ｒ^ｅ８及びＲ^ｅ９（Ｒ^ｅ７〜Ｒ^ｅ９）はそれぞれ独立に、炭素数１〜２０のアルキル基、炭素数３〜１８の脂環式炭化水素基、炭素数６〜１８の芳香族炭化水素基、又は式（ｅ１−４）

（式（ｅ１−４）中、
Ｒ^ｅ１０及びＲ^ｅ１１はそれぞれ独立に、炭素数１〜２０のアルキル基、炭素数３〜１８の脂環式炭化水素基又は炭素数６〜１８の芳香族炭化水素基を表す。Ｒ^ｅ１０及びＲ^ｅ１１が互いに結合し、これらが結合する窒素原子とともに環を形成してもよい。
該アルキル基、脂環式炭化水素基及び芳香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のアルキル基、炭素数１〜１２のアルコキシ基又は３〜１８の脂環式炭化水素基で置換されてもよい。
Ｌ^ｅ１は、炭素数１〜５の２価の脂肪族炭化水素基を表し、該２価の脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わってもよい。）
で表される基であり、Ｒ^ｅ７〜Ｒ^ｅ９のうち少なくとも１つは式（ｅ１−４）で表される基である。該アルキル基、該脂環式炭化水素基及び該芳香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のアルキル基、炭素数１〜１２のアルコキシ基又は３〜１８の脂環式炭化水素基で置換されてもよい。］
〔６〕 前記塩（Ｂ４）の含有質量が、前記塩（Ｅ１）の含有質量よりも多い〔１〕〜〔５〕のいずれか記載のレジスト組成物。
〔７〕 前記樹脂（Ａ）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樹脂である〔１〕〜〔６〕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、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１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^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１〜１０の脂肪族炭化水素基を表す。
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。］
〔８〕（１）〔１〕〜〔７〕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、
（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 (A) having an acid-decomposable group;
Formula (B4)

[In the formula (B4),
A ⁺ represents an acid-decomposable group and an organic cation having no nitrogen atom.
X _a ^- has an acid-decomposable group, it represents an organic sulfonate anion having no nitrogen atom. ]
A salt (B) represented by:
Formula (E1)

[In the formula (E1),
A _N represents an organic cation having a nitrogen atom.
X ^- represents an organic sulfonate anion having no nitrogen atom. ]
The resist composition containing the salt (E1) represented by these.
[2] A ^{+ in the} formula (B4) is an organic sulfonium cation having no acid-decomposable group and a nitrogen atom, and A _N ^{+ in the} formula (E1) is an organic sulfonium cation having a nitrogen atom. [1] The resist composition according to [1].
[3] The resist composition according to [1] or [2], wherein X _a ^{− in the} formula (B4) is an organic sulfonate anion represented by the formula (b4-1) or (b4-2).

[In the formula (b4-1),
^Xb1 represents an acid-decomposable group having no nitrogen atom.
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent linking group having no nitrogen atom. ]

[In the formula (b4-2)
^Xb represents an acid-decomposable group having no nitrogen atom.
m4 represents an integer of 1 or 2, and when m4 is 2, two existing ^Xb are the same or different. ]
[4] The resist composition according to [3], wherein the organic sulfonate anion represented by the formula (b4-1) is an organic sulfonate anion represented by the formula (b4-1-A).

[In the formula (b4-1-A),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^{b1 ″} and L ^{b1 ′} each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic hydrocarbon group is , Oxygen atom or carbonyl group may be substituted.
Y ^b1 represents a phenylene group or a single bond that may have an alkyl group having 1 to 5 carbon atoms.
^Xb represents an acid-decomposable group having no nitrogen atom. ]
[5] A _N ^{+ in the} formula (E1) is an organic cation represented by any one of the formula (e1-1), the formula (e1-2), and the formula (e1-3) [1] to [ 4]. The resist composition according to any one of 4).

[In the formula (e1-1),
R ^e1 and R ^e2 each independently represent a hydrogen atom, a halogen atom, a hydroxy group, a cyano group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an acyl group having 2 to 5 carbon atoms. .
In formula (e1-2),
R ^e3 represents a hydroxy group or an alkyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkyl group may be replaced with an oxygen atom or a carbonyl group.
R ^e4 and R ^e6 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
m7 represents an integer of 0 to 3. m8 and m9 each independently represent 1 or 2.
When m7 is 2 or 3, a plurality of R ^e3 are the same or different.
When m8 is 2, two R ^e4 are the same or different.
When m9 is 2, two R ^e6 are the same or different.
R ^e5 represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkyl group may be replaced with an oxygen atom or a carbonyl group.
m10 represents 0 or 1. ]
In formula (e1-3),
R ^e7 , R ^e8 and R ^e9 (R ^{e7 to} R ^e9 ) are each independently an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic group having 6 to 18 carbon atoms. Hydrocarbon group or formula (e1-4)

(In the formula (e1-4),
R ^e10 and R ^e11 each independently represent an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R ^e10 and R ^e11 may be bonded to each other and form a ring together with the nitrogen atom to which they are bonded.
The hydrogen atom contained in the alkyl group, alicyclic hydrocarbon group and aromatic hydrocarbon group is a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an alicyclic group having 3 to 18 carbon atoms. It may be substituted with a hydrocarbon group.
L ^e1 represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms, and the methylene group constituting the divalent aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. )
And at least one of R ^{e7 to} R ^e9 is a group represented by the formula (e1-4). The hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group is a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an aliphatic group having 3 to 18 carbon atoms. It may be substituted with a cyclic hydrocarbon group. ]
[6] The resist composition according to any one of [1] to [5], wherein the content mass of the salt (B4) is larger than the content mass of the salt (E1).
[7] The resin (A) is
The resist composition according to any one of [1] to [6], which is a resin having a structural unit represented by formula (a1-1) or a structural unit represented by formula (a1-2).

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to a carbonyl group. Represent.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]
[8] (1) A step of applying the resist composition according to any one of [1] to [7] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A step of heating the composition layer after exposure,
(5) a step of developing the composition layer after heating;
A method for producing a resist pattern including:

  According to the resist composition of the present invention, a resist pattern having excellent line edge roughness (LER) can be produced.

  The resist composition of the present invention is a resin (A) having an acid-decomposable group [hereinafter referred to as “resin (A)” in some cases. ] And a salt (B4) represented by the formula (B4) [hereinafter referred to as “salt (B4)” in some cases. And a salt (E1) represented by the formula (E1) [hereinafter referred to as “salt (E1)” in some cases. And containing.

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

In the present specification, the hydrocarbon group includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group.
The aliphatic hydrocarbon group includes both a chain type and a cyclic type, and includes a combination of a chain type and an alicyclic aliphatic hydrocarbon group unless otherwise defined. Further, these aliphatic hydrocarbon groups may contain a carbon-carbon double bond in a part thereof, but a saturated group (aliphatic saturated hydrocarbon group) is preferable.

［式（Ｂ４）中、
Ａ^＋は、酸分解性基及び窒素原子を有さない有機カチオンを表す。
Ｘ_ａ ⁻は、酸分解性基を有し、窒素原子を有さない有機スルホン酸アニオンを表す。］ <Salt (B4)>
The salt (B4) is represented by the following formula (B4).

[In the formula (B4),
A ⁺ represents an acid-decomposable group and an organic cation having no nitrogen atom.
X _a ^- has an acid-decomposable group, it represents an organic sulfonate anion having no nitrogen atom. ]

The acid-decomposable group possessed by the organic sulfonate anion (X _a ⁻ ) means a group that can be decomposed by the action of an acid, and preferably a group that decomposes by the action of an acid to form a hydrophilic group. Examples of the hydrophilic group include a hydroxy group and a carboxy group. As described above, the acid-decomposable group capable of decomposing by the action of an acid to form a hydrophilic group is an acid-decomposable group of a resin having an acid-decomposable group contained in a chemically amplified resist composition. Well known acid-decomposable groups.

［式（１）中、
Ｒ^a1、Ｒ^a２及びＲ^a3（Ｒ^a1〜Ｒ^a3）は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜２０の脂環式炭化水素基を表すか、Ｒ^a1及びＲ^a2は互いに結合して炭素数２〜２０の脂肪族炭化水素基を形成する。＊は結合手を表す。］

［式（２）中、
Ｒ^ａ1’及びＲ^ａ２’は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ３’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^ａ２’及びＲ^ａ３’は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。該炭化水素基を構成するメチレン基は、酸素原子又は硫黄原子に置き換わってもよい。＊は結合手を表す。］ More preferable acid-decomposable groups include a group represented by the formula (1) (hereinafter sometimes referred to as “acid-decomposable group (1)”) and a group represented by the formula (2) (hereinafter, cases). For example, "acid-decomposable group (2)").

[In Formula (1),
R ^a1 , R ^a2 and R ^a3 (R ^{a1 to} R ^a3 ) each independently represent an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^a1 and R a ^a2 combine with each other to form an aliphatic hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]

[In Formula (2),
R ^{a1 ′} and R ^{a2 ′} each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^{a2 ′} and R ^{a3 ′} is bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms. The methylene group constituting the hydrocarbon group may be replaced with an oxygen atom or a sulfur atom. * Represents a bond. ]

多環式の脂環式炭化水素基としては、以下の式（ＫＡ-8）〜（ＫＡ-19）で表される脂環式炭化水素から水素原子を１個取り去ることにより形成される基が挙げられる。

^Examples of the alkyl group represented by R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include groups formed by removing one hydrogen atom from a cycloalkane represented by the following formulas (KA-1) to (KA-7).

Examples of the polycyclic alicyclic hydrocarbon group include groups formed by removing one hydrogen atom from an alicyclic hydrocarbon represented by the following formulas (KA-8) to (KA-19). Can be mentioned.

Specific examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Specific examples of the polycyclic saturated hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, a methylnorbornyl group, and the following groups (in the formula, * represents a bond). Can be mentioned. In the formula (1), the alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms.

When R ^a1 and R ^a2 are bonded to each other to form an aliphatic hydrocarbon group, the group represented by the —C (R ^a1 ) (R ^a2 ) (R ^a3 ) group is represented by any of the following: And the carbon number of the divalent hydrocarbon group formed by R ^a1 and R ^a2 being bonded to each other is preferably in the range of 3-12.

Examples of the acid-decomposable group (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), groups in which R ^{a1 to} R ^a3 are alkyl groups, preferably R ^{a1 to} R ^a3 At least one is a tert-butyl group.), 2-alkyladamantan-2-yloxycarbonyl group (in formula (1), R ^a1 and R ^a2 are bonded together with the carbon atom to which they are bonded, and adamantane A group in which R ^a3 is an alkyl group) and 1- (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in formula (1), R ^a1 and R ^a2 are alkyl groups, group in which ^a3 is an adamantyl group).

Examples of the hydrocarbon group for R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining an alkyl group and an alicyclic hydrocarbon group. And a group formed by combining an alkyl group and an aromatic hydrocarbon group.
Examples of the alkyl group and the alicyclic hydrocarbon group are the same as those described above for R ^{a1 to} R ^a3 .
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the group formed by combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, an isobornyl group, and a 2-alkyladamantan-2-yl group. Group, 1- (adamantan-1-yl) alkane-1-yl group and the like.
The group formed by combining an alkyl group and an aromatic hydrocarbon group is, for example, an aralkyl group, and specifically includes a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Groups and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include a group obtained by removing one hydrogen atom from the hydrocarbon group.
When the hydrocarbon group is an alkyl group or an alicyclic hydrocarbon group, one or two methylene groups constituting the group may be replaced with an oxygen atom or a sulfur atom.
At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

Specific examples of the acid-decomposable group (2) include the following groups.

［式（ｂ４−１）中、
Ｘ^ｂ１は窒素原子を有さない酸分解性基、好ましくは酸分解性基（１）又は酸分解性基（２）を表す。
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、窒素原子を有さない２価の連結基を表す。］ Preferable examples of the organic sulfonate anion (X _a ⁻ ) include anions represented by the formula (b4-1) or the formula (b4-2).

[In the formula (b4-1),
X ^b1 represents an acid-decomposable group having no nitrogen atom, preferably an acid-decomposable group (1) or an acid-decomposable group (2).
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent linking group having no nitrogen atom. ]

式（ｂ４−２）中、
Ｘ^ｂは、前記式（ｂ４−１）と同様に、窒素原子を有さない酸分解性基、好ましくは、酸分解性基（１）又は酸分解性基（２）を表す。
ｍ４は１又は２の整数を表す。ｍ４が２である場合、２つのＸ^ｂは互いに同一又は相異なる。

In formula (b4-2),
X ^b represents an acid-decomposable group having no nitrogen atom, preferably an acid-decomposable group (1) or an acid-decomposable group (2), as in the formula (b4-1).
m4 represents an integer of 1 or 2. When m4 is 2, two ^Xb are the same or different from each other.

［式（ｂ４−１−Ａ）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1''及びＬ^ｂ１'は、単結合又は炭素数１〜１７の２価の脂肪族炭化水素基を表し、該２価の脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙ^ｂ１は、炭素数１〜５のアルキル基を有していてもよいフェニレン基又は単結合を表す。
Ｘ^ｂは、窒素原子を有さない酸分解性基を表す。］ Examples of the organic sulfonate anion represented by the formula (b4-1) include an organic sulfonate anion represented by the formula (b4-1-A).

[In the formula (b4-1-A),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^{b1 ″} and L ^{b1 ′} represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic hydrocarbon group is an oxygen atom or a carbonyl group. It may be replaced with a group.
Y ^b1 represents a phenylene group or a single bond that may have an alkyl group having 1 to 5 carbon atoms.
^Xb represents an acid-decomposable group having no nitrogen atom. ]

Examples of the perfluoroalkyl group of Q ¹ and Q ² include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Groups.
R ² and R ³ are preferably each independently a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.
The divalent linking group having no nitrogen atom of L ^b1 is preferably a divalent hydrocarbon group having 1 to 24 carbon atoms, and the methylene group contained in the hydrocarbon group is an oxygen atom or a carbonyl group. It may be replaced with.
Examples of such a divalent linking group include * -CO-L ^b2- , * -CO-OL- ^b2- , * -CO-OL- ^b2 -O-, * ^-CO- OL. ^{b2 -CO -, * - CO-} O-L b2 -O-CO -, * - CO-O-L b2 -CO-O -, * - CO-O-L b2 -O-L b3 -, * - CO—O—L ^b2 —CO—O—L ^b3 —, * —CO—O—L ^b2 —O—CO—L ^b3 —, * —L ^b2 —O—L ^b3 —, * —L ^b2 —CO—. ^{O-L b3 -, * -} L b2 -O-CO-L b3 -, * - CO-O-L b2 -O-L b3 -O-L b4 - and * ^-CO-O-L b2 -O- L ^b3 —CO—L ^b4 — and the like, preferably, * —CO—O—L ^b2 —, * —CO—O—L ^b2 —O—, * —CO—O—L ^b2 —CO—, *- ^{O-O-L b2 -O-} CO -, * - CO-O-L b2 -CO-O -, * - CO-O-L b2 -O-L b3 -, * - CO-O-L b2 - CO—O—L ^b3 —, * —CO—O—L ^b2 —O—CO—L ^b3 —, more preferably * —CO—O—L ^b2 —, * —CO—O—L ^b2 —. ^{CO -, * - CO-O} -L b2 -O-L b3 -, * - CO-O-L b2 -CO-O-L b3 - a.
* Represents a bond with C (Q ¹ ) (Q ² ).
L ^b2 , L ^b3 and L ^b4 each independently represent a hydrocarbon group having 1 to 12 carbon atoms.
Examples of the hydrocarbon group of L ^b2 , L ^b3 and L ^b4 include an alkanediyl group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, and a divalent group obtained by combining these. The methylene group contained in the divalent alicyclic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total carbon number of the divalent linking group is 24 or less. This carbon number represents the carbon number before the methylene group is replaced with an oxygen atom or a carbonyl group.

Examples of the divalent hydrocarbon group include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic hydrocarbon group, and a divalent aromatic hydrocarbon group. Or a combination of two or more of these groups.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group;
An alkyl group (preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, or a tert-butyl group) on the linear alkylene side Having a chain, for example, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl A branched alkanediyl group such as a 2-methylbutane-1,4-diyl group;
A simple cycloalkanediyl group such as cyclobutane-1,3-diyl group, 1,3-cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, etc. A cyclic divalent alicyclic hydrocarbon group;
Polycyclic divalent alicyclic rings such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, 1,5-adamantane-1,5-diyl group, adamantane-2,6-diyl group A hydrocarbon group of formula;
Examples thereof include a divalent aromatic hydrocarbon group which is an arylene group obtained by removing one hydrogen atom from an aryl group such as a phenyl group, a naphthyl group, an antonyl group, a biphenyl group, a phenanthryl group and a fluorenyl group.

Examples of the divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms represented by L ^{b1 ″} and L ^{b1 ′} in formula (b4-1-A) include the aforementioned alkanediyl group having 1 to 17 carbon atoms, A cyclic or polycyclic C3-C17 bivalent alicyclic hydrocarbon group is mentioned, You may combine 2 or more types among these groups. The methylene group constituting the divalent aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
^Examples of the alkyl group having 1 to 5 carbon atoms represented by Y ^b1 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and a pentyl group.

なお、ここに示す有機スルホン酸アニオン（Ｘ_ａ ⁻）の具体例において、式中、Ｑ^１、Ｑ^２、Ｒ^ａ１、Ｒ^ａ２、Ｒ^ａ３、Ｒ^ａ１’、Ｒ^ａ２’、Ｒ^ａ３’、Ｌ^ｂ２及びＬ^ｂ３は前記と同義である。 Specific examples of the organic sulfonate anion (X _a ⁻ ) are shown below.

In the specific examples of the organic sulfonate anion (X _a ⁻ ) shown here, Q ¹ , Q ² , R ^a1 , R ^a2 , R ^a3 , R ^{a1 ′} , R ^{a2 ′} , R ^{a3 ′} , L ^b2 and L ^b3 are as defined above.

In the formula (B4), the organic cation (A ⁺ ) does not have both the acid-decomposable group and the nitrogen atom. The organic cation (A ⁺ ) is preferably an organic onium cation. Examples of the organic onium cation include an organic sulfonium cation, an organic iodonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among them, an organic sulfonium cation and an organic iodonium cation are preferable, and an organic sulfonium cation is more preferable. Among the organic sulfonium cations, an arylsulfonium cation in which at least one aryl group is bonded to a sulfur atom which is a cation center is particularly preferable.

Preferable A ⁺ includes an organic cation represented by any one of formulas (b2-1) to (b2-4).

In formula (b2-1) to formula (b2-4),
R ^b4 , R ^b5 and R ^b6 each independently represent an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R ^b4 and R ^b5 may be bonded to each other to form a ring together with the carbon atom to which they are bonded. The hydrogen atom contained in the alkyl group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and is included in the alicyclic hydrocarbon group. The hydrogen atom may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group is a halogen atom, a hydroxy group, or a carbon number It may be substituted with an -18 alkyl group, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl 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 an integer of 2 or more, the plurality of R ^b7 are the same or different from each other, and when n2 is an integer of 2 or more, the plurality of R ^b8 are the same or different from each other.

R ^b9 and R ^b10 each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The alkyl group of R ^{b9 to} R ^b11 is preferably in the range of 1 to 12 carbon atoms, and the alicyclic hydrocarbon group is preferably in the range of 3 to 18 carbon atoms, and in the range of 4 to 12 carbon atoms. More preferably.
R ^b12 represents an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkylcarbonyloxy group having 1 to 12 carbon atoms. May be substituted.
R ^b9 and R ^b10 , and R ^b11 and R ^b12 may be independently bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring). The methylene group constituting these rings may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.

R ^{b13 to} R ^b18 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b11 represents an oxygen atom or a sulfur atom.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is an integer of 2 or more, the plurality of R ^b13 are the same or different from each other. When p2 is an integer of 2 or more, the plurality of R ^b14 are the same or different from each other, and s2 is an integer of 2 or more. The plurality of R ^b17 are the same or different from each other, and when u2 is an integer of 2 or more, the plurality of R ^b18 are the same or different from each other, and when q2 is an integer of 2 or more, the plurality of R ^b15 are When r2 is the same or different and r2 is an integer of 2 or more, the plurality of R ^b16 are the same or different from each other.

炭素数６〜１８の芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ｐ−メチルフェニル基、ｐ−ｔｅｒｔ−ブチルフェニル基、ｐ−アダマンチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、ビフェニル基、フェナントリル基、２，６−ジエチルフェニル基、２−メチル−６−エチルフェニル等のアリール基等が挙げられる。
炭素数１〜１２のアルコキシ基としては、メトキシ基、エトキシ基、プロポキシ基、ブトキシ基、ペンチルオキシ基、ヘキシルオキシ基、ヘプチルオキシ基、オクチルオキシ基、デシルオキシ基及びドデシルオキシ基などが挙げられる。
ハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子等が挙げられる。
炭素数２〜４のアシル基としては、例えば、アセチル基、プロピオニル基及びブチリル基などが挙げられる。
炭素数１〜１２のアルキルカルボニルオキシ基としては、炭素数１〜１２のアルキル基とカルボニルオキシ基とが結合したものが挙げられる。 Examples of the alkyl group having 1 to 30 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 -An ethylhexyl group is mentioned. The alicyclic hydrocarbon group having 3 to 18 carbon atoms may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, Examples thereof include cycloalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, a methylnorbornyl group, and the following groups. * Represents a bond. Preferably, they are a cyclopentyl group and a cyclohexyl group.

Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, and cumenyl. Groups, mesityl groups, biphenyl groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the acyl group having 2 to 4 carbon atoms include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group having 1 to 12 carbon atoms include those in which an alkyl group having 1 to 12 carbon atoms and a carbonyloxy group are bonded.

Preferred examples of the alkyl group ^{represented by} R ^{b9 to} R ^b12 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 an octyl group. And 2-ethylhexyl group.
Preferred examples of the alicyclic hydrocarbon group represented by R ^{b9 to} R ^b11 include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyl-2-adamantyl group, 1- (1 -Adamantyl) -1-alkyl group and isobornyl group.
Preferred examples of the aromatic hydrocarbon group for R ^b12 include phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, And biphenylyl and naphthyl groups.
A group in which an aromatic hydrocarbon group of R ^b12 and an alkyl group are bonded is typically an aralkyl group.
Examples of the ring formed by combining the combination of R ^b9 and R ^b10 include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Etc.
Examples of the ring formed by combining the combination of R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Specific examples of the cation (b2-1), cation (b2-2), cation (b2-3), and cation (b2-4) include those described in JP 2010-204646 A.

式（ｂ２−１−１）中、
Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、炭素数１〜１８のアルキル基又は炭素数１〜１２のアルコキシ基を表す。
このアルキル基の炭素数は１〜１２の範囲であると好ましく、脂環式炭化水素基の炭素数は４〜１８の範囲であると好ましい。
前記アルキル基は、ヒドロキシ基、炭素数１〜１２のアルコキシ基又は炭素数６〜１８の芳香族炭化水素基で置換されていてもよい。
前記脂環式炭化水素基は、ハロゲン原子、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い。
ｖ２、ｗ２及びｘ２は、それぞれ独立に０〜５の整数（好ましくは０又は１）を表す。
ｖ２が２以上のとき、複数のＲ^b19は互いに同一又は相異なり、ｗ２が２以上のとき、複数のＲ^b20は互いに同一又は相異なり、ｘ２が２以上のとき、複数のＲ^b21は互いに同一又は相異なる。
なかでも、Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、好ましくは、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、炭素数１〜１２のアルキル基、又は炭素数１〜１２のアルコキシ基である。 Among the exemplified organic cations, those represented by the formula (b2-1) are preferable, and organic cations represented by the following formula (b2-1-1) [hereinafter referred to as “cation (b2-1-1)” That's it. ] Is more preferable, and a triphenylsulfonium cation (in the formula (b2-1-1), v2 = w2 = x2 = 0) is further preferable.

In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
The alkyl group preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
The alkyl group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The alicyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, the plurality of R ^b19 are the same or different from each other. When w2 is 2 or more, the plurality of R ^b20 are the same or different from each other. When x2 is 2 or more, the plurality of R ^b21 are the same. Or different.
Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. It is a group.

<Specific example of salt (B4)>
The salt (B4) is an arbitrary combination of the above-described anion (X _a ⁻ ) and the above-described organic cation (A ⁺ ). Preferable combinations include acid generators represented by the following formula, and acid generators described in JP2011-46694A, JP2011-126896A, and JP2005-97254A. Such a salt (B4) can be easily obtained by those skilled in the art according to the production method described in the patent document exemplified in the present specification.

［式（Ｅ１）中、
Ａ_Ｎは窒素原子を有する有機カチオンを表す。
Ｘ⁻は、窒素原子を有さない有機スルホン酸アニオンを表す。］ <Salt (E1)>
The salt (E1) is represented by the following formula (E1).

[In the formula (E1),
A _N represents an organic cation having a nitrogen atom.
X ^- represents an organic sulfonate anion having no nitrogen atom. ]

In the formula (E1), A _N ⁺ is an organic cation having a nitrogen atom. A _N ⁺ may or may not have an acid-decomposable group. The organic cation (A _N ⁺ ) is preferably an organic onium cation having a nitrogen atom. Examples of organic onium cations include organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. The nitrogen atom of the organic cation (A _N ⁺ ) is preferably a basic nitrogen atom other than the quaternary nitrogen atom. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an organic sulfonium cation is more preferable. Among the organic sulfonium cations, an arylsulfonium cation in which at least one aryl group is bonded to a sulfur atom which is a cation center is particularly preferable.

［式（ｅ１−１）中、
Ｒ^ｅ１及びＲ^ｅ２、それぞれ独立に、水素原子、ハロゲン原子、水酸基、シアノ基、炭素数１〜１０のアルキル基、炭素数１〜４のアルコキシ基又は炭素数２〜５のアシル基を表す。
式（ｅ１−２）中、
Ｒ^ｅ３は、水酸基又は炭素数１〜１２のアルキル基を表し、該アルキル基を構成する−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｒ^ｅ４及びＲ^ｅ６は、それぞれ独立に、水素原子又は炭素数１〜６のアルキル基を表す。
ｍ７は、０〜３の整数を表す。ｍ８及びｍ９は、それぞれ独立に、１又は２を表す。
ｍ７が２又は３であるとき、複数存在するＲ^ｅ3は同一であるか、相異なる。
ｍ８が２であるとき、２つ存在するＲ^ｅ４は同一であるか、相異なる。
ｍ９が２であるとき、２つ存在するＲ^ｅ６は同一であるか、相異なる。
Ｒ^ｅ５は、水素原子又は炭素数１〜１２のアルキル基を表し、該アルキル基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ｍ１０は、０又は１を表す。
式（ｅ１−３）中、
Ｒ^ｅ７、Ｒ^ｅ８及びＲ^ｅ９（Ｒ^ｅ７〜Ｒ^ｅ９）はそれぞれ独立に、炭素数１〜２０のアルキル基、炭素数３〜１８の脂環式炭化水素基、炭素数６〜１８の芳香族炭化水素基、又は式（ｅ１−４）

（式（ｅ１−４）中、
Ｒ^ｅ１０及びＲ^ｅ１１はそれぞれ独立に、炭素数１〜２０のアルキル基、炭素数３〜１８の脂環式炭化水素基又は炭素数６〜１８の芳香族炭化水素基を表す。Ｒ^ｅ１０及びＲ^ｅ１１が互いに結合し、これらが結合する窒素原子とともに環を形成してもよい。
該アルキル基、脂環式炭化水素基及び芳香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のアルキル基、炭素数１〜１２のアルコキシ基又は３〜１８の脂環式炭化水素基で置換されてもよい。
Ｌ^ｅ１は、炭素数１〜５の２価の脂肪族炭化水素基を表し、該２価の脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わってもよい。）
で表される基であり、Ｒ^ｅ７〜Ｒ^ｅ９のうち少なくとも１つは式（ｅ１−４）で表される基である。該アルキル基、該脂環式炭化水素基及び該芳香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のアルキル基、炭素数１〜１２のアルコキシ基又は３〜１８の脂環式炭化水素基で置換されてもよい。］ Preferable examples of the organic cation (A _N ⁺ ) constituting the salt (E1) include formulas (e1-1), (e1-2) and (e1-3) [formula (e1-1) to formula (e1). -3)].

[In the formula (e1-1),
R ^e1 and R ^e2 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a cyano group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an acyl group having 2 to 5 carbon atoms.
In formula (e1-2),
R ^e3 represents a hydroxyl group or an alkyl group having 1 to 12 carbon atoms, and —CH ₂ — constituting the alkyl group may be replaced by —O— or —CO—.
R ^e4 and R ^e6 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
m7 represents an integer of 0 to 3. m8 and m9 each independently represent 1 or 2.
When m7 is 2 or 3, a plurality of R ^e3 are the same or different.
When m8 is 2, two R ^{e4 s} are the same or different.
When m9 is 2, two R ^e6 are the same or different.
R ^e5 represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkyl group may be replaced with an oxygen atom or a carbonyl group.
m10 represents 0 or 1.
In formula (e1-3),
R ^e7 , R ^e8 and R ^e9 (R ^{e7 to} R ^e9 ) are each independently an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic group having 6 to 18 carbon atoms. Hydrocarbon group or formula (e1-4)

(In the formula (e1-4),
R ^e10 and R ^e11 each independently represent an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R ^e10 and R ^e11 may be bonded to each other and form a ring together with the nitrogen atom to which they are bonded.
The hydrogen atom contained in the alkyl group, alicyclic hydrocarbon group and aromatic hydrocarbon group is a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an alicyclic group having 3 to 18 carbon atoms. It may be substituted with a hydrocarbon group.
L ^e1 represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms, and the methylene group constituting the divalent aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. )
And at least one of R ^{e7 to} R ^e9 is a group represented by the formula (e1-4). The hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group is a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an aliphatic group having 3 to 18 carbon atoms. It may be substituted with a cyclic hydrocarbon group. ]

  In formula (e1-1) to formula (e1-3), examples of the alkyl group, alkoxy group, and acyl group are the same as those described above.

In the organic cation represented by the formula (e1-1), both R ^e1 and R ^e2 are preferably hydrogen atoms. There is an advantage that the salt (E1) composed of the organic cation (A _N ⁺ ) represented by the formula (e1-1) in which R ^e1 and R ^e2 are hydrogen atoms can be easily produced.

で表される部分構造は、

であることが好ましい。 In the organic cation represented by the formula (e1-2), R ^e3 is preferably a hydroxy group or an alkyl group having 1 to 6 carbon atoms. M7 is preferably 0 or 1.
M8 and m9 are preferably 2, and R ^e4 and R ^e6 are preferably hydrogen atoms. That is, in the formula (e1-2)

The partial structure represented by

It is preferable that

Preferable examples of the organic cation represented by the formula (e1-2) are as follows.

Wherein (E1), X ^- organic sulfonic acid anion represented by (X ^-) is a sulfonate group (* -SO ₃ ^-., * Is a bond) has, no nitrogen atom It is an anion characterized by this.

［式（ｘ１）中、
Ｑ^３及びＱ^４は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^ｅ２は、炭素数１〜１７の２価の脂肪族炭化水素基又は単結合を表し、該２価の脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該アルキル基及び該脂環式炭化水素基を構成するメチレン基は、酸素原子、カルボニル基又はスルホニル基に置き換わっていてもよい。］ Examples of the organic sulfonate anion (X ⁻ ) include anions represented by the formulas (x1) and (x2).

[In the formula (x1),
Q ³ and Q ⁴ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
^Le2 represents a C1-C17 divalent aliphatic hydrocarbon group or a single bond, and the methylene group constituting the divalent aliphatic hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. Good.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. The methylene group constituting the alicyclic hydrocarbon group may be replaced with an oxygen atom, a carbonyl group or a sulfonyl group. ]

［式（ｘ２）中、
Ｒａは、置換基群Ｐ１から選ばれる基を有してもよい炭素数１〜２０の脂肪族炭化水素基、又は、置換基群Ｐ２から選ばれる基を炭素数６〜２０の芳香族炭化水素基を表す。
置換基群Ｐ１：炭素数１〜１０アルコキシ基、炭素数２〜１１のアルコキシカルボニル基、ハロゲン原子、ヒドロキシ基及びニトロ基
置換基群Ｐ２：炭素数１〜１５のアルキル基、炭素数１〜１０アルコキシ基、炭素数２〜１１のアルコキシカルボニル基、ハロゲン原子、ヒドロキシ基及びニトロ基］

[In the formula (x2),
Ra is an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a group selected from substituent group P1, or an aromatic hydrocarbon having 6 to 20 carbon atoms selected from substituent group P2. Represents a group.
Substituent group P1: C1-C10 alkoxy group, C2-C11 alkoxycarbonyl group, halogen atom, hydroxy group, and nitro group Substituent group P2: C1-C15 alkyl group, C1-C10 Alkoxy group, C2-C11 alkoxycarbonyl group, halogen atom, hydroxy group and nitro group]

Specific examples of Q ³ and Q ^{4 in} the formula (x1) are the same as Q ¹ and Q ² included in the formula (B4). Q ¹ and Q ² contained in the salt (B4) contained in the resist composition and Q ³ and Q ⁴ contained in the salt (E1) are not necessarily the same.

A specific example of L ^{e2 in} the formula (x1) is the same as a specific example of L ^{b1 in} the formula (b4-1). L ^b1 contained in the salt (B4) contained in the resist composition and L ^e2 contained in the salt (E1) are not necessarily the same.

The number of carbon atoms of the Y alkyl group in the formula (x1) is preferably in the range of 1 to 6, and specific examples thereof include the same as those described above. The number of carbon atoms in the alicyclic hydrocarbon group is preferably in the range of 3 to 17, and specific examples thereof include the same ones as described above.
Examples of the substituent that the alkyl group and the alicyclic hydrocarbon group optionally have include, for example, a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and carbon. C3-C16 alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C4 acyl group , Glycidyloxy group or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or carbon Represents an aromatic hydrocarbon group of formula 6 to 18. j2 represents an integer of 0 to 4).
The hydroxy group-containing alkyl group is an alkyl group having at least one hydroxy group, and examples thereof include a hydroxymethyl group and a hydroxyethyl group. Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms. Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, n-hexoxy group and the like. Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like. Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, naphthylethyl group and the like. Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.

  The methylene group constituting the aliphatic hydrocarbon group for Y may be replaced with a group (divalent group) selected from the group consisting of an oxygen atom, a sulfonyl group and a carbonyl group. Examples of the group in which the methylene group constituting the alicyclic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group or a carbonyl group include, for example, a cyclic ether group (one or two of the methylene groups constituting the alicyclic hydrocarbon group are A group in which an oxygen atom is substituted), a cyclic ketone group (a group in which one or two methylene groups constituting an alicyclic hydrocarbon group are replaced by a carbonyl group), a sultone ring group (which constitutes an alicyclic hydrocarbon group) Two adjacent methylene groups in the methylene group are replaced with oxygen atoms and sulfonyl groups, respectively, and a lactone ring group (two methylene groups adjacent in the methylene group constituting the alicyclic hydrocarbon group, A group in which an oxygen atom and a carbonyl group are substituted, respectively).

As the alicyclic hydrocarbon group for Y, groups represented by formulas (Y1) to (Y26) are preferable.

  Among these, Preferably it is group represented by either of Formula (Y1)-Formula (Y19), More preferably, it is represented by Formula (Y11), Formula (Y14), Formula (Y15) or Formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

As described above, the alicyclic hydrocarbon group for Y may have a substituent. Examples of the alicyclic hydrocarbon group having such a substituent include the following.

  The alicyclic hydrocarbon group of Y is preferably a group having an adamantane ring as shown in Formula (Y11) and Formula (Y14), and when these have a substituent, the substituent is preferably a hydroxy group . That is, as the alicyclic hydrocarbon group having a substituent, a hydroxyadamantyl group is particularly preferable as Y.

Specifically, when the organic sulfonate anion (A _a ⁺ ) represented by the formula (x1) is specifically shown, the sulfonate anion represented by the formula (b1-1-1) to the formula (b1-1-1-9) Is mentioned. In these formulas, Q ¹ , Q ² and L ^b2 are as defined above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).

Next, the organic sulfonate anion represented by the formula (x2) will be described.
When Ra in the formula (x2) is an aliphatic hydrocarbon group, specific examples thereof include the already exemplified alkyl groups, alicyclic hydrocarbon groups, and combinations thereof. Such an aliphatic hydrocarbon group may have a group selected from the substituent group P1, and the substituent that the aliphatic hydrocarbon group has is preferably a halogen atom among the substituent group P1. When Ra is an aromatic hydrocarbon group, specific examples thereof include those already exemplified. In addition, the aromatic hydrocarbon group may have a substituent selected from the substituent group P2, but the substituent that the aromatic hydrocarbon group has is an alkyl group among the substituent group P2. And a halogen atom are preferred.

などが挙げられる。 Specifically, when an organic sulfonate anion represented by the formula (x2) is exemplified,

Etc.

<Specific examples of salt (E1)>
The salt (E1) is an arbitrary combination of the above-described organic cation (A _N ⁺ ) and the above-described organic sulfonate anion (X ⁻ ). Specific examples include the following salts.

（式中、全ての符号は前記と同義である。）
この反応の触媒としては、安息香酸銅（ＩＩ）などが挙げられ、溶剤としては、モノクロロベンゼンなどが挙げられる。 Examples of the salt (E1) containing an organic cation represented by the formula (e1-2) include a compound represented by the formula (e1-2-a), a salt represented by the formula (e1-2b), and Can be produced in a solvent in the presence of a catalyst.

(In the formula, all symbols are as defined above.)
Examples of the catalyst for this reaction include copper (II) benzoate, and examples of the solvent include monochlorobenzene.

The compound represented by the formula (e1-2b) may be prepared according to desired R ^{e4 to} R ^e6 , m8 and m9, and for example, a compound which can be easily obtained from the market can be used. Examples of such commercially available products include the compounds represented below.

（式中、全ての符号は、前記と同義である。）
この反応の溶剤としては、クロロホルム及び水などが挙げられる。
式（ｅ１−２−ｃ）で表される化合物は、市場から容易に入手できるものを用いることにより準備できる。このような市販品としては例えば、ジフェニルヨードニウム クロライドなどが挙げられる。
式（ｅ１−２−ｄ）で表される化合物は、例えば特開２００８−２０９９１７号公報に記載された方法によって製造することができる。 Examples of the compound represented by the formula (e1-2-a) include a compound represented by the formula (e1-2c) and a compound represented by the formula (e1-2-d) in a solvent. It can be produced by reacting.

(In the formula, all symbols are as defined above.)
Examples of the solvent for this reaction include chloroform and water.
The compound represented by the formula (e1-2c) can be prepared by using a compound that can be easily obtained from the market. Examples of such commercially available products include diphenyliodonium chloride.
The compound represented by the formula (e1-2-d) can be produced, for example, by the method described in JP2008-209917A.

<Resin (A)>
The resin (A) contained in the resist composition is a resin having an acid-decomposable group. Examples of such an acid labile group include groups already decomposed by the action of an acid to form a hydrophilic group described in the organic cation (A _a ⁺ ) constituting the salt (B3). Among the resins (A) having such an acid-decomposable group, the resin itself is insoluble or hardly soluble in an alkaline aqueous solution, but is preferably one that can be dissolved in an alkaline aqueous solution by the action of an acid. The resin (A) is a monomer having an acid-decomposable group (hereinafter sometimes referred to as “monomer (a1)”, and a structural unit derived from the monomer (a1) is referred to as “structural unit (a1)”). It can be produced by polymerization. “Becomes soluble in alkali by the action of an acid” means “being insoluble or hardly soluble in an aqueous alkali solution before contact with an acid, but soluble in an aqueous alkali solution after contact with an acid”. means. When manufacturing resin (A), a monomer (a1) may be used individually by 1 type, and may use 2 or more types together.

The acid-decomposable group of the resin (A) is preferably the acid-decomposable group (1) or the acid-decomposable group (2) described in the organic sulfonate anion (X ⁻ ) constituting the salt (B4). The decomposable group (1) is more preferred.

  The structural unit (a1) of the resin (A) preferably has an alicyclic hydrocarbon group having 5 to 20 carbon atoms. The present resist composition containing the resin (A) having such a bulky structure has an advantage that a resist pattern can be produced with excellent resolution.

  The monomer (a1) for deriving the structural unit (a1) is preferably an acid-decomposable group [more preferably, an acid-decomposable group (1) and / or an acid-decomposable group (2)], and carbon-carbon. A monomer having a double bond in the molecule is preferable, and a (meth) acrylic monomer having an acid-decomposable group (1) and a carbon-carbon double bond in the molecule is more preferable.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、互いに独立に、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１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^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１〜１０の脂肪族炭化水素基を表す。
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。］ <Preferred structural unit (a1)>
The resin (A) having a suitable structural unit (a1) will be further described in detail. Among the resins (A), a structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as “structural unit (a1-1)”) or a structural unit represented by the formula (a1-2) A resin having (hereinafter, referred to as “structural unit (a1-2)” in some cases) is preferable. Such resin (A) may have a single type of structural unit (a1-1), may have multiple types, or may have a single type of structural unit (a1-2). In addition, a plurality of types may be included, and the structural unit (a1-1) and the structural unit (a1-2) may be combined.

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

^K1 in ^* —O— (CH ₂ ) _k1 —CO—O— of L ^a1 and L ^a2 is preferably an integer of 1 to 4, and more preferably 1. L ^a1 and L ^a2 are preferably oxygen atoms.
R ^a4 and R ^a5 are preferably methyl groups.
The aliphatic hydrocarbon group for R ^a6 and R ^a7 is preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms. The alkyl group preferably has 6 or less carbon atoms. The alicyclic hydrocarbon group preferably has 8 or less carbon atoms, more preferably 6 or less carbon atoms.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

Examples of the monomer (a1) for deriving the structural unit (a1-1) include monomers described in JP-A No. 2010-204646. As the structural unit (a1-1), structural units respectively represented by formulas (a1-1-1) to (a1-1-8) are preferable, and formulas (a1-1-1) to (a1-1) are preferable. The structural units represented by -5) are more preferable.

  Examples of the monomer that leads to the structural unit (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptane-1- Examples include yl (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, and 1-isopropylcyclopentan-1-yl (meth) acrylate.

The structural unit (a1-2) is preferably a structural unit represented by each of the formulas (a1-2-1) to (a1-2-12)], more preferably the formula (a1- 2-3), structural units (a1-2) represented by (a1-2-4), (a1-2-7) and (a1-2-8), respectively, more preferably 2-3) and structural units represented by (a1-2-7), respectively.

  When resin (A) has a structural unit (a1-1) and / or a structural unit (a1-2), these total content rates are with respect to all the structural units (100 mol%) of resin (A). The range of 10-95 mol% is preferable, the range of 15-90 mol% is more preferable, the range of 20-85 mol% is further more preferable, and the range of 20-60 mol% is especially preferable.

  The structural unit (a1) is preferably a structural unit having an adamantyl group (particularly preferably, the structural unit (a1-1)). When the structural unit (a1) having an adamantyl group is included, the content ratio is preferably 15 mol% or more with respect to the total of the structural units (a1). If the content of the acid labile structural unit having an adamantyl group is within the above range, the dry etching resistance of a resist pattern produced from the resist composition containing the resin (A) tends to be good.

  The structural unit (a1-1) and the structural unit (a1-2) that are preferable as the structural unit (a1) included in the resin (A) have been described above. However, the resin (A) includes structural units (a1) other than these. You may have. Hereinafter, the structural unit (a1) other than the structural unit (a1-1) and the structural unit (a1-2) will be described by showing a monomer (a1) that derives the structural unit (a1).

［式（ａ１−３）中、
Ｒ^a9は、水素原子、置換基（例えばヒドロキシ基）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、又は−ＣＯＯＲ^a13を表し、Ｒ^a13は、炭素数１〜８の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子はヒドロキシ基等に置換されていてもよく、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｒ^a10、Ｒ^a11及びＲ^a12は、互いに独立に、炭素数１〜１２の脂肪族炭化水素基を表すか、Ｒ^a10及びＲ^a11は互いに結合してこれらが結合する炭素原子とともに環を形成し、Ｒ^a12は、炭素数１〜１２の脂肪族炭化水素基を表す。該脂肪族炭化水素基及に含まれる水素原子はヒドロキシ基等で置換されていてもよく、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ The resin (A) may have a structural unit (a1) derived from the monomer represented by the formula (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”). Since the resin (A) having the structural unit (a1) derived from such a monomer (a1-3) contains a rigid norbornane ring in the main chain, the present resist composition containing the resin (A) Products tend to be able to produce resist patterns with excellent dry etching resistance.

[In the formula (a1-3),
R ^a9 is hydrogen atom or a substituent (e.g. hydroxy groups) of 1 to 3 carbon atoms which may have an aliphatic hydrocarbon group, a carboxy group, a cyano group, or a -COOR ^a13, R ^a13 is Represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, a hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and a methylene group constituting the aliphatic hydrocarbon group is: An oxygen atom or a carbonyl group may be substituted.
R ^a10 , R ^a11 and R ^a12 each independently represent an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or R ^a10 and R ^a11 are bonded to each other to form a ring together with the carbon atom to which they are bonded. , R ^a12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The aliphatic hydrocarbon group of R ^{a9 to} R ^a12 is typically an alkyl group, and specific examples of the alkyl group include those already exemplified in the range of 1 to 12 carbon atoms. Examples of the aliphatic hydrocarbon group having a substituent, particularly a hydroxy group, include a hydroxymethyl group and a 2-hydroxyethyl group.

Examples of the ring and R ^a10 and R ^a11 are formed with bonded carbon atoms to which they are attached, and the like cyclohexane ring and an adamantane ring cyclohexylene.

As a monomer (a1-3), what was described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Among these, monomers represented by the formula (a1-3-1), the formula (a1-3-2), the formula (a1-3-3) and the formula (a1-3-4) are preferable, respectively. The monomer represented by a1-3-2) or (a1-3-4) is more preferred, and the monomer represented by formula (a1-3-2) is more preferred.

  When the resin (A) has the structural unit (a1) derived from the monomer (a1-3), the content ratio is preferably in the range of 10 to 95 mol% with respect to all the structural units of the resin (A). The range of 15-90 mol% is more preferable, and the range of 20-85 mol% is more preferable.

［式（ａ１−４）中、
Ｒ¹⁰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。
ｌａは０〜４の整数を表す。
Ｒ¹¹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し、ｌａが２以上である場合、複数のＲ¹¹は互いに同一であっても異なってもよい。
Ｒ¹²及びＲ¹³は互いに独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｙ^a3は、置換基を有していてもよい炭素数１〜１８の炭化水素基を表す。］ The resin (A) may have a structural unit (a1) derived from the monomer represented by the formula (a1-4) (hereinafter sometimes referred to as “monomer (a1-4)”).

[In the formula (a1-4),
R ¹⁰ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
la represents an integer of 0 to 4.
R ¹¹ 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 When a methacryloyloxy group is represented and la is 2 or more, a plurality of R ¹¹ may be the same as or different from each other.
R ¹² and R ¹³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
Y ^a3 represents an ^optionally substituted hydrocarbon group having 1 to 18 carbon atoms. ]

R ¹⁰ is preferably an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, more preferably a methyl group and a hydrogen atom, and still more preferably a hydrogen atom.
The alkoxy group of R ¹¹ is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group and an ethoxy group, and particularly preferably a methoxy group.
The hydrocarbon group of R ¹² and R ¹³ is preferably an aliphatic hydrocarbon group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 12 carbon atoms.
The hydrocarbon group for Y ^a3 is preferably an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, and more preferably one having 1 carbon atom. An aliphatic hydrocarbon group having 18 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. When the hydrocarbon group of Y ^a3 is an aliphatic hydrocarbon group, an unsubstituted aliphatic hydrocarbon group is preferable, and when the hydrocarbon group of Y ^a3 is an aromatic hydrocarbon group, the substituent includes A 1-6 alkyl group and a C6-C10 aryloxy group are preferable.

As a monomer (a1-4), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Especially, the monomer respectively represented by Formula (a1-4-1)-Formula (a1-4-7) is preferable, and each is represented by Formula (a1-4-1)-Formula (a1-4-5). Monomers are more preferred.

  When the resin (A) has a structural unit (a1) derived from the monomer (a1-4), the content ratio is preferably in the range of 10 to 95 mol% with respect to all the structural units of the resin (A). The range of 15 to 90 mol% is more preferable, and the range of 20 to 85 mol% is more preferable.

［式（ａ１−５）中、
Ｒ^a8は、水素原子又はメチル基を表す。
Ａ^１は、単結合、酸素原子又はカルボニル基を表す。
Ａ^２は炭素数１〜６のアルカンジイル基を表す。
Ｒ^a1〜Ｒ^a3は、上記と同じ意味である。］ In addition, the resin (A) is a structural unit represented by the following formula (a1-5) as a structural unit (a1) having an adamantane ring (hereinafter sometimes referred to as “structural unit (a1-5)”). May have.

[In the formula (a1-5),
R ^a8 represents a hydrogen atom or a methyl group.
A ¹ represents a single bond, an oxygen atom or a carbonyl group.
A ² represents an alkanediyl group having 1 to 6 carbon atoms.
R ^{a1 to} R ^a3 have the same meaning as described above. ]

R ^{a1 to} R ^{a3 in} the structural unit (a1-5) are each independently a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, and a hexyl group, or R ^a2 and R ^a3 are bonded to each other, It is preferable to form a ring having 3 to 12 carbon atoms together with the carbon atom to which they are bonded. The ring is preferably an adamantane ring or a cyclohexane ring.

As a structural unit (a1-5), the following structural units are mentioned, for example.

  When the resin (A) has the structural unit (a1-5), the content ratio is preferably in the range of 3 to 80 mol%, more preferably 5 to 70 mol%, with respect to all the structural units of the resin (A). The range is more preferable, and the range of 5 to 60 mol% is more preferable.

<Acid stable structural unit>
In addition to the structural unit (a1) having an acid-decomposable group, the resin (A) is a structural unit having no acid-decomposable group (hereinafter sometimes referred to as “acid-stable structural unit”). The derivatizable monomer is preferably referred to as “acid-stable monomer”). In the resin (A), the acid stable structural unit may have only one type, or may have a plurality of types. 1 type may be sufficient as the acid stable structural unit in resin (A), and 2 or more types may be sufficient as it.
When the resin (A) has the structural unit (a1) and the acid stable structural unit, the acid stable structural unit is obtained by subtracting the content of the acid stable structural unit from 100 mol%. In addition, the ratio of the content ratio of the structural unit (a1) and the content ratio of the acid-stable structural unit is usually the total use of the monomer (a1) derived from the structural unit (a1) when the resin (A) is produced. The preferred range is determined by the ratio of the amount and the total amount of acid stable monomer used to derive the acid stable structural unit. Specifically, it is expressed in the form of [monomer (a1)] / [acid-stable monomer], preferably 10 to 80 mol% / 90 to 20 mol%, more preferably 20 to 60 mol% / 80 to 40 mol%. If it does in this way, there exists a tendency for the dry etching tolerance of the resist pattern obtained from this resist composition containing resin (A) to become still better.

Next, a preferable thing is demonstrated among an acid stable structural unit.
The acid stable structural unit is preferably a structural unit having a hydroxy group or a lactone ring. An acid stable structural unit having a hydroxy group (hereinafter referred to as “acid stable structural unit (a2)”) and / or an acid stable structural unit having a lactone ring (hereinafter referred to as “acid stable structural unit (a3)”). When the present resist composition containing the resin (A) is applied to a substrate, the resin (A) having the coating film formed on the substrate or the composition layer obtained from the coating film is between the substrate It becomes easy to express excellent adhesiveness, and the resist composition can produce a resist pattern with high resolution. In addition, the manufacturing method of the resist pattern using this resist composition here is mentioned later. First, the acid stable structural unit (a2) and the acid stable structural unit (a3) suitable as the acid stable structural unit will be described with specific examples.

<Acid stable structural unit (a2)>
When the acid-stable structural unit (a2) is introduced into the resin (A), a suitable acid-stable structure is used depending on the type of exposure source when producing a resist pattern from the resist composition containing the resin (A). The unit (a2) can be selected. That is, when this resist composition is used for exposure using a KrF excimer laser (wavelength: 248 nm) as an exposure source, or exposure using a high energy beam such as an electron beam or EUV light as an exposure source, an acid stable structural unit ( As a2), it is preferable to introduce an acid stable structural unit (a2-0) having a phenolic hydroxyl group into the resin (A). When using exposure using a short wavelength ArF excimer laser (wavelength: 193 nm) as an exposure source, an acid stable structural unit represented by the formula (a2-1) described later is used as a resin ( It is preferable to introduce into A). Thus, each of the acid stable structural units (a2) possessed by the resin (A) can be selected according to the exposure source used for producing the resist pattern, but the acid stable structural units possessed by the resin (A) ( a2) may have only one type of acid stable structural unit (a2) suitable for the type of exposure source, and two or more types of acid stable structural unit (a2) suitable for the type of exposure source. Or an acid stable structural unit (a2) suitable for the type of exposure source and a combination of other acid stable structural units (a2).

式（ａ２−１）中、
Ｌ^a3は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−（ｋ２は１〜７の整数を表す。）で表される基を表し、＊はカルボニル基（−ＣＯ−）との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 One specific example of the acid stable structural unit (a2) is one represented by the following formula (a2-1) (hereinafter sometimes referred to as “acid stable structural unit (a2-1)”).

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

L ^a3 is preferably an oxygen atom or a group represented by —O— (CH ₂ ) _k2 —CO—O—, wherein k2 is an integer of 1 to 4, and more preferably an oxygen atom.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

As an acid stable structural unit (a2-1), the following are mentioned, for example.

  As described above, the exemplified acid stable structural unit (a2-1) is derived from, for example, an acid stable monomer described in JP 2010-204646 A. Among these, acid stable structural units (a2) represented by formula (a2-1-1), formula (a2-1-2), formula (a2-1-3) and formula (a2-1-4), respectively. -1) is more preferable, and the acid stable structural unit (a2-1) represented by the formula (a2-1-1) to the formula (a2-1-3) is more preferable.

  When the resin (A) has an acid stable structural unit (a2-1), the content ratio is preferably in the range of 1 to 45 mol% with respect to all the structural units of the resin (A), and 2 to 35 The range of mol% is more preferable, and the range of 3 to 30 mol% is more preferable.

式（ａ２−０）中、
Ｒ^a30は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^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は同一でも異なっていてもよい。 Next, the acid stable structural unit (a2) having a phenolic hydroxy group among the acid stable structural units (a2) having a hydroxy group will be described. Examples of the acid stable structural unit (a2) include those represented by the following formula (a2-0) (hereinafter sometimes referred to as “acid stable structural unit (a2-0)”).

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

R ^a30 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.
R ^a31 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and still more preferably 0.

The acid stable structural unit (a2-0) is represented by formula (a2-0-1), formula (a2-0-2), formula (a2-0-3) and formula (a2-0-4), respectively. Are preferred. Examples of the acid stable monomer for deriving the structural unit (a2-0) include monomers described in JP2010-204634A.

  By using an acid-stable monomer capable of deriving an acid-stable structural unit (a2-0) such as p-hydroxystyrene or p-hydroxy-α-methylstyrene for the production of the resin (A), the formula (a2-0-1) Alternatively, the acid stable structural unit (a2-0) represented by the formula (a2-0-2) can be introduced into the resin (A1), but the phenolic hydroxy group in the acid stable monomer is, for example, acetyl After protecting with a protecting group such as a group to form a protected acid stable monomer, the resin (A) can also be produced using this protected acid stable monomer. A resin (A1) having an acid stable structural unit (a2-0) can be produced by deprotecting a resin having a structural unit derived from a protected acid-stable monomer and removing the protecting group. However, when carrying out the deprotection treatment, it is necessary to carry out the deprotection treatment so that the acid labile group of the structural unit (a1) is not significantly impaired.

  When the resin (A) has an acid stable structural unit (a2-0), the content is preferably in the range of 5 to 90 mol%, and preferably 10 to 85 mol% with respect to all the structural units of the resin (A). Is more preferable, and the range of 15 to 80 mol% is more preferable.

<Acid stable structural unit (a3)>
The lactone ring possessed by the acid stable structural unit (a3) may be monocyclic such as β-propiolactone ring, γ-butyrolactone ring and δ-valerolactone ring, monocyclic lactone ring and other rings. Or a condensed ring. Among these lactone rings, a γ-butyrolactone ring and a condensed ring of a γ-butyrolactone ring and another ring are preferable.

［式（ａ３−１）中、
Ｌ^a4は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）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。
ｐ１は０〜５の整数を表す。
Ｒ^a21は炭素数１〜４の脂肪族炭化水素基を表し、ｐ１が２以上の場合、複数のＲ^a21は互いに同一又は相異なる。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）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。
ｑ１は、０〜３の整数を表す。
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し、ｑ１が２以上の場合、複数のＲ^a22は互いに同一又は相異なる。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）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。
ｒ１は、０〜３の整数を表す。
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し、ｒ１が２以上の場合、複数のＲ^a23は互いに同一又は相異なる。］ The acid stable structural unit (a3) is preferably one represented by the following formula (a3-1), formula (a3-2) or formula (a3-3). Resin (A) may have only 1 type among these, and may have 2 or more types. In the following description, what is represented by the formula (a3-1) is referred to as “acid-stable structural unit (a3-1)”, and what is represented by the formula (a3-2) is “acid-stable structural unit ( a3-2) ”, and the compound represented by formula (a3-3) is referred to as“ acid-stable structural unit (a3-3) ”.

[In the formula (a3-1),
L ^a4 represents an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
p1 represents an integer of 0 to 5.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when p1 is 2 or more, the plurality of R ^a21 are the same or different from each other.
In formula (a3-2),
L ^a5 represents an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
q1 represents an integer of 0 to 3.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when q1 is 2 or more, the plurality of R ^a22 are the same or different from each other.
In formula (a3-3),
L ^a6 represents an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
r1 represents an integer of 0 to 3.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when r1 is 2 or more, the plurality of R ^a23 are the same or different from each other. ]

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 are the same as those described for L ^a3 in formula (a2-1).
L ^{a4 to} L ^a6 are each independently an oxygen atom or a group represented by * —O— (CH ₂ ) _k3 —CO—O— in which k3 is an integer of 1 to 4, preferably an oxygen atom and * —O—CH ₂ —CO—O— is more preferable.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are preferably integers of 0 to 2, more preferably 0 or 1. When p1 is 2, two R ^a21 may be the same as or different from each other. When q1 is 2, two R ^a22 may be the same as or different from each other, and r1 is 2. Two R ^a23 may be the same or different from each other.

  Hereinafter, preferred examples of the acid stable structural unit (a3-1), the acid stable structural unit (a3-2), and the acid stable structural unit (a3-3) will be shown.

Preferable examples of the acid stable structural unit (a3-1) include the following formula (a3-1-1), formula (a3-1-2), formula (a3-1-3) and formula (a3-1-4). ).

Preferable examples of the acid stable structural unit (a3-2) include the following formula (a3-2-1), formula (a3-2-2), formula (a3-2-3) and formula (a3-2-4). ).

Preferred examples of the acid stable structural unit (a3-3) include the following formula (a3-3-1), formula (a3-3-2), formula (a3-3-3) and formula (a3-3-4). ).

  As an acid stable monomer which can derive | lead an acid stable structural unit (a3-3), what was described in Unexamined-Japanese-Patent No. 2010-204646 can be mentioned, for example.

  When the resin (A) has an acid stable structural unit (a3-3), the content ratio is preferably in the range of 5 to 70 mol% with respect to all the structural units of the resin (A), 10 to 65 The range of mol% is more preferable, and the range of 10 to 60 mol% is more preferable.

  The resin (A) may have an acid stable structural unit other than the acid stable structural unit (a2) and the acid stable structural unit (a3) (hereinafter sometimes referred to as “acid stable structural unit (a4)”). Examples of the acid stable structural unit (a4) include those known in the resist field. For example, examples of the acid stable monomer that leads to the acid stable structural unit (a4) include styrene, α-methylstyrene, 4 -Methyl styrene, 2-methyl styrene, 3-methyl styrene, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, tetracyclododecenyl (meth) acrylate, and the like, preferably styrene, α -Methylstyrene, 4-methylstyrene, 2-methylstyrene and 3-methylstyrene.

  When the resin (A) has such an acid-stable structural unit (a4), the content ratio is preferably 60 mol% or less, and 50 mol% or less with respect to all the structural units of the resin (A). More preferred is a range of 40 mol% or less.

More preferable specific examples of the resin (A) include the following resins (A-1) to (A-17).

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

<Method for producing resin (A)>
The resin (A) is obtained by copolymerizing the monomer (a1) for deriving the structural unit (a1), more preferably the monomer (a1) and an acid stable monomer for deriving the acid stable structural unit. More preferably, the monomer (a1), the acid stable structural unit (a2) and / or the acid stable structural unit (a3) for deriving the structural unit (a1-1) and / or the structural unit (a1-2) are derived. It is a copolymer of an acid stable monomer.
The resin (A) further preferably has a structural unit (a1-1) having an adamantyl group as the structural unit (a1). As the acid stable structural unit (a2), it is preferable to use a structural unit (a2-1) having a hydroxyadamantyl group. The acid stable structural unit (a3) includes at least an acid stable structural unit (a3-1) having a γ-butyrolactone ring and an acid stable structural unit (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring. It is preferable to have one. The resin (A) can be produced by subjecting the monomer as described above to a known polymerization method (for example, radical polymerization method) and polymerizing (copolymerizing) it.

  The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less). In addition, the weight average molecular weight here is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis. Detailed analysis conditions for this analysis are described in the Examples of the present application.

<Basic compound (C)>
The resist composition of the present invention may contain a basic compound that acts as a quencher well known in the art. Hereinafter, this basic compound is sometimes referred to as “basic compound (C)”.

  The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by the formula (C1) to a compound represented by the formula (C8), more preferably a compound represented by the formula (C1-1). It is done.

［式（Ｃ１）中、
Ｒ^c1、Ｒ^c2及びＲ^c3は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基、炭素数５〜１０の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基を表し、該アルキル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、アミノ基又は炭素数１〜６のアルコキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、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５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。］

[In the formula (C1),
R ^c1 , R ^c2 and R ^c3 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. The hydrogen atom contained in the alkyl group and the alicyclic hydrocarbon group may be substituted with a hydroxy group, an amino group, or an alkoxy group having 1 to 6 carbon atoms, and the aromatic hydrocarbon group The hydrogen atom contained is substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms. It may be. ]

［式（Ｃ１−１）中、
Ｒ^c2及びＲ^c3は、前記と同義である。
Ｒ^c4は、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５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4は互いに同一又は相異なる。］

[In the formula (C1-1),
R ^c2 and R ^c3 are as defined above.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, the plurality of R ^c4 are the same or different from each other. ]

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、
Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同義である。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は互いに同一又は相異なる。］

[In Formula (C2), Formula (C3) and Formula (C4),
R ^c5 , R ^c6 , R ^c7 and R ^c8 are each independently synonymous with R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 are the same or different from each other. ]

［式（Ｃ５）及び式（Ｃ６）中、
Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、それぞれ独立に、Ｒ^c1と同義である。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同義である。
ｏ３及びｐ３は、それぞれ独立に０〜３の整数を表し、ｏ３が２以上であるとき、複数のＲ^c14は互いに同一又は相異なる。ｐ３が２以上であるとき、複数のＲ^c15は互いに同一又は相異なる。
Ｌ^c1は、炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C5) and Formula (C6),
R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 are each independently synonymous with R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently have the same ^meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3, and when o3 is 2 or more, the plurality of R ^c14 are the same or different from each other. When p3 is 2 or more, the plurality of R ^c15 are the same or different from each other.
L ^c1 represents an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

［式（Ｃ７）及び式（Ｃ８）中、
Ｒ^c18、Ｒ^c19及びＲ^c20は、それぞれ独立に、Ｒ^c4と同義である。
ｑ３、ｒ３及びｓ３は、それぞれ独立に０〜３の整数を表し、ｑ３が２以上であるとき、複数のＲ^c18は同一又は相異なる。ｒ３が２以上であるとき、複数のＲ^c19は同一又は相異なる。ｓ３が２以上であるとき、複数のＲ^c20は同一又は相異なる。
Ｌ^c2は、単結合又は炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C7) and Formula (C8),
R ^c18, R ^c19 and R ^c20 in each occurrence independently has the same meaning as R ^c4.
q3, r3 and s3 each independently represent an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 are the same or different. When r3 is 2 or more, the plurality of R ^c19 are the same or different. When s3 is 2 or more, the plurality of R ^c20 are the same or different.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

  Examples of the compound represented by the formula (C1) 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, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenyl Examples include ethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, and 4,4′-diamino-3,3′-diethyldiphenylmethane. Propyl aniline. Particularly preferred include 2,6-diisopropylaniline.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 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, and bipyridine.

  As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Examples include ammonium hydroxide, tetra-n-butylammonium salicylate, and choline.

<Solvent (D)>
The resist composition of the present invention preferably contains a solvent. Hereinafter, this solvent is sometimes referred to as “solvent (D)”. Solvent (D) is a resin (A), salt (B3), salt (E1), etc., and the solubility according to the amount thereof, and the resist composition of the present invention is applied onto a substrate in the production of a resist pattern. From the standpoint of good coating properties during the process, an optimal one can be selected as appropriate.

  Examples of the solvent (D) 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 Examples thereof include esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone. A solvent (D) may be used individually by 1 type, and may use 2 or more types together.

<Other components (hereinafter sometimes referred to as “component (F)”)>
If necessary, the resist composition of the present invention contains components (F) other than the resin (A), the salt (B3), the salt (E2), the basic compound (C) and the solvent (D) according to the present invention. It may be contained as long as the characteristics of the resist composition are not significantly impaired. Examples of the component (F) include additives widely used in this technical field, and examples thereof include a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, and a dye.

<Method for Preparing Resist Composition of the Present Invention>
Then, the preparation method of this resist composition containing resin (A), salt (B4), and salt (E1) is demonstrated.
The resist composition of the present invention is, for example, by mixing resin (A), salt (B4), salt (E1) and solvent (D),
Or
It can prepare by mixing resin (A), salt (B4), salt (E1), additives, such as a basic compound (C) and a component (F), and a solvent (D). In such mixing, the mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select the suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to solvent (D), such as a kind (resin (A)), such as resin (A). 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.

  A preferable range of the content of the salt (B4) in the resist composition of the present invention is determined based on the content of the resin (A). Specifically, the salt (B4) is preferably 1 part by mass or more and 40 parts by mass or less, and more preferably 3 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the resin (A).

  A preferable range of the content of the salt (E1) in the resist composition of the present invention is determined based on the content of the resin (A). Specifically, the salt (E1) is preferably 0.5 parts by mass or more and 20 parts by mass or less, and more preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the resin (A). .

  As described above, the content of the salt (B4) and the salt (E1) in the resist composition of the present invention has a preferable range based on the content of the resin (A), but the salt in the resist composition of the present invention. The content of (B4) is particularly preferably larger than the content of salt (E1) in the resist composition of the present invention. When the content ratio of the salt (B4) and the salt (E1) is expressed in the form of [salt (B4)] / [salt (E1)] (weight ratio), the range of 20/1 to 5/1 is preferable.

  A preferable range of the content ratio of the resin (A) in the resist composition of the present invention is determined based on the solid content of the resist composition of the present invention. Specifically, the resin (A) is preferably 70% by mass or more based on the mass of the solid content. In addition, the mass of "solid content" here means the sum total of the component remove | excluding the solvent (D) which is a volatile component from this resist composition containing a solvent (D). The solid content can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  When the resist composition of the present invention contains a basic compound (C), the content is preferably about 0.01 to 6% by mass, based on the mass of the solid content of the resist composition, 0.01 to About 4% by mass is more preferable, and about 0.01 to 3% by mass is particularly preferable.

  In the resist composition of the present invention containing the solvent (D), the content of the solvent (D) is preferably 90% by mass or more and 92% by mass or more based on the total mass of the resist composition of the present invention. More preferred is 94% by mass or more. The content of the solvent (D) is preferably 99.9% by mass or less, and more preferably 99% by mass or less. The content ratio of the solvent (D) may be determined by analysis means such as chromatography or gas chromatography, as in the method of measuring the mass of the solid content.

  When the component (F) is contained in the resist composition of the present invention, an appropriate content can be determined according to the type of the component (F).

  The resist composition of the present invention containing the solvent (D) comprises a resin (A), a salt (B3), a salt (E2) and a solvent (D), and a basic compound (C) or a solvent used as necessary. It can be prepared by mixing each component (F) at a preferred content and then filtering with a filter having a pore size of about 0.2 μm.

<Method for producing resist pattern>
A method for producing a resist pattern using the resist composition of the present invention,
(1) The process of apply | coating the resist composition of this invention on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure,
(5) A step of developing the composition layer after heating is included.
including. Hereinafter, each of the steps shown here is referred to as “step (1)” to “step (5)”.

  The coating of the resist composition of the present invention on the substrate in the step (1) can be performed by a coating apparatus widely used for coating a resist composition for semiconductor microfabrication, such as a spin coater. Thus, a coating film made of the resist composition of the present invention is formed on the substrate. The film thickness of the coating film can be adjusted by variously adjusting the conditions (coating conditions) of the coating apparatus, and by applying an appropriate preliminary experiment, the coating film can be applied to have a desired film thickness. You can choose the conditions. As the substrate before applying the resist composition of the present invention, various substrates to be subjected to fine processing can be selected. In addition, before apply | coating the resist composition of this invention, a board | substrate can be wash | cleaned or an antireflection film can also be formed. For example, a commercially available composition for an organic antireflection film can be used for forming the antireflection film.

In step (2), the resist composition of the present invention applied on the substrate, that is, the coating film is dried. dry. Such solvent removal can be performed by, for example, heating means (pre-baking) using a heating device such as a hot plate, decompressing means using a decompressing device, or a combination of these means, and removing the solvent (D) from the coating film. Is performed by evaporating. The conditions for the heating means and the decompression means are adjusted according to the type of the solvent (D) contained in the resist composition. For example, in the heating means (hot plate heating) using a hot plate, What is necessary is just to make surface temperature into the range of about 50-200 degreeC. In the decompression means, after the substrate on which the coating film is formed is sealed in an appropriate decompressor, the internal pressure of the decompressor may be set to about 1 to 1.0 × 10 ⁵ Pa. Thus, by removing the solvent (D) from the coating film, a composition layer is formed on the substrate.

Step (3) is a step of exposing the composition layer, and preferably the composition layer is exposed using an exposure machine. At this time, exposure is performed through a mask corresponding to a desired pattern to be finely processed. As an exposure light source of the exposure machine, an ultraviolet light emitting device such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ laser (wavelength 157 nm), a solid-state laser light source (YAG or Various types of laser light such as a semiconductor laser or the like that converts wavelength of laser light to emit harmonic laser light in the far ultraviolet region or the vacuum ultraviolet region can be used. The exposure machine may be an immersion exposure machine. In addition, "exposure" here is a general term for irradiating these radiations.
As described above, by exposing through a mask, an exposed portion (exposed portion) and an unexposed portion (unexposed portion) are generated in the composition layer. In the composition layer of the exposed portion, the acid generator (salt (B4) and / or salt (E1)) contained in the composition layer receives an exposure energy to generate an acid. The acid-decomposable group in (A) causes a deprotection reaction, and as a result, the resin (A) in the composition layer of the exposed portion becomes soluble in an alkaline aqueous solution. On the other hand, since the exposure energy is not received in the unexposed area, the resin (A) remains insoluble or hardly soluble in the alkaline aqueous solution. Thus, the composition layer in the exposed portion and the composition layer in the unexposed portion are significantly different in solubility in the alkaline aqueous solution.

  In step (4), a heat treatment for further promoting the progress of the deprotecting group reaction that may occur in the exposed portion is performed. For this heat treatment, the heating means (post exposure bake) using the hot plate shown in the step (2) is employed. In the hot plate heating in step (4), the surface temperature of the hot plate is preferably about 50 to 200 ° C, more preferably about 70 to 150 ° C.

Step (5) is a step of developing the heated composition layer, and preferably the heated composition layer is developed with a developing device. By contacting the heated composition layer with an aqueous alkali solution, the exposed composition layer is dissolved in the alkaline aqueous solution, and leaving the unexposed composition layer on the substrate, a resist pattern is formed on the substrate. Is manufactured.
The alkaline aqueous solution used here is referred to as “alkaline developer”, and those used in this technical field can be used. Examples of the alkaline aqueous solution include an aqueous solution of tetramethylammonium hydroxide and an aqueous solution of (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).

  According to the method for producing a resist pattern including the steps (1) to (5) as described above, the resist composition of the present invention can produce a resist pattern having excellent line edge roughness (LER).

  In addition, after the steps (1) to (5) are performed, it is also preferable to rinse the manufactured resist pattern with ultrapure water and remove the cleaning water remaining on the resist pattern.

<Uses of resist composition of the present invention>
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) irradiation, or a resist composition for an EUV exposure machine. It is. Among these, the resist composition of the present invention is particularly excellent as a resist composition for EB irradiation or an EUV exposure machine.

Hereinafter, the present invention will be described in detail by way of examples.
In Examples and Comparative Examples, “%” and “part” representing the content and the amount used are based on mass unless otherwise specified.
In the following examples, the structure of the compound was confirmed by mass spectrometry (LC; Agilent 1100 type, MASS; Agilent LC / MSD type).
The weight average molecular weight is a value determined by gel permeation chromatography (HLC-8120GPC type manufactured by Tosoh Corporation, three columns are “TSKgel Multipore HXL-M”, and the solvent is tetrahydrofuran) using polystyrene as a standard product.
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

式（Ｂ４−１−１）で表される化合物５．００部及びジメチルホルムアミド２５部を反応器に仕込み、２３℃で３０分間攪拌した。その後、トリエチルアミン３．８７部を滴下し、さらに、２３℃で３０分間攪拌した。得られた混合物に、式（Ｂ４−１−２）で表される化合物６．５７部をジメチルホルムアミド６．５７部に溶解した溶液を、３０分かけて滴下し、さらに、２３℃で２時間攪拌した。得られた反応混合物に、イオン交換水２３．５０部及び酢酸エチル１４０．９９部を加え、２３℃で３０分間攪拌した後、静置・分液し、有機層を回収した。回収された有機層に、イオン交換水７０．５０部を仕込み２３℃で３０分間攪拌した後、静置・分液し、有機層を回収するという水洗操作をさらに６回繰り返した。得られた有機層を濃縮し、得られた濃縮物に、ｎ−ヘプタン９２．２０部を添加して攪拌した後、析出物をろ過することにより、式（Ｂ４−１−３）で表される塩２．８５部を得た。 Synthesis Example 1 (Salt (B4); Synthesis of B4-1)

5.00 parts of a compound represented by the formula (B4-1-1) and 25 parts of dimethylformamide were charged into a reactor and stirred at 23 ° C. for 30 minutes. Thereafter, 3.87 parts of triethylamine was dropped, and the mixture was further stirred at 23 ° C. for 30 minutes. A solution obtained by dissolving 6.57 parts of the compound represented by the formula (B4-1-2) in 6.57 parts of dimethylformamide was added dropwise to the obtained mixture over 30 minutes, and further at 23 ° C. for 2 hours. Stir. To the resulting reaction mixture, 23.50 parts of ion-exchanged water and 140.99 parts of ethyl acetate were added and stirred at 23 ° C. for 30 minutes, then allowed to stand and liquid-separated to recover the organic layer. The recovered organic layer was charged with 70.50 parts of ion-exchanged water and stirred at 23 ° C. for 30 minutes, and then allowed to stand and liquid-separated, and the water washing operation of recovering the organic layer was further repeated 6 times. The obtained organic layer was concentrated. To the obtained concentrate, 92.20 parts of n-heptane was added and stirred, and then the precipitate was filtered, thereby being represented by the formula (B4-1-3). 2.85 parts of a salt was obtained.

式（Ｂ４−１−４）で表される化合物を、特開２００８−１２７３６７号公報に記載された方法で合成した。
式（Ｂ４−１−４）で表される化合物２．９９部及びアセトニトリル１５．００部を反応器に仕込み、２３℃で３０分間攪拌した後、式（ＩＩＩ）で表される化合物１．３０部を添加した。その後、７０℃まで昇温し、同温度で２時間攪拌した。得られた反応混合物を２３℃まで冷却した後、不溶物をろ過により除去し、式（ＩＩＩ−１）で表される化合物を含む溶液を得た。
この式（ＩＩＩ−１）で表される化合物を含む溶液に、式（Ｂ４−１−３）で表される化合物２．３０部をクロロホルム６．８９部に溶解した溶液を添加し、２３℃で２３時間攪拌した。得られた反応混合物を濃縮した後、得られた濃縮物に、クロロホルム５８．４７部及び２％シュウ酸水溶液２９．２４部を仕込み、攪拌・静置・分液を行い、有機層を回収した。回収した有機層にシュウ酸水溶液を添加し、攪拌・静置・分液するというシュウ酸水溶液洗浄操作を２回繰り返した。回収された有機層に、イオン交換水２９．２４部を仕込み、攪拌・静置・分液するという水洗操作を４回繰り返した。得られた有機層を濃縮し、得られた濃縮物をアセトニトリル２７．２７部に溶解した後、濃縮した。得られた濃縮物に、ｔｅｒｔ−ブチルメチルエーテル７０．００部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解した後、濃縮することにより、式（Ｂ４−１）で表される塩３．５８部を得た。これをＢ４−１とする。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ５３１．２

The compound represented by the formula (B4-1-4) was synthesized by the method described in JP2008-127367A.
2.99 parts of the compound represented by the formula (B4-1-4) and 15.00 parts of acetonitrile were charged into a reactor, stirred at 23 ° C. for 30 minutes, and then the compound 1.30 represented by the formula (III). Parts were added. Then, it heated up to 70 degreeC and stirred at the same temperature for 2 hours. After cooling the obtained reaction mixture to 23 ° C., insoluble matters were removed by filtration to obtain a solution containing the compound represented by the formula (III-1).
A solution prepared by dissolving 2.30 parts of the compound represented by the formula (B4-1-3) in 6.89 parts of chloroform was added to the solution containing the compound represented by the formula (III-1), For 23 hours. After concentrating the obtained reaction mixture, the obtained concentrate was charged with 58.47 parts of chloroform and 29.24 parts of 2% aqueous oxalic acid solution, stirred, allowed to stand, and separated to recover the organic layer. . The oxalic acid aqueous solution washing operation of adding the oxalic acid aqueous solution to the collected organic layer and stirring, standing, and separating was repeated twice. The washing operation of charging 29.24 parts of ion-exchanged water into the collected organic layer and stirring, standing, and separating was repeated 4 times. The obtained organic layer was concentrated, and the resulting concentrate was dissolved in 27.27 parts of acetonitrile and then concentrated. To the obtained concentrate, 70.00 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile, and concentrated to obtain 3.58 parts of the salt represented by the formula (B4-1). This is designated as B4-1.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ^- 531.2

式（Ｂ４−２−１）で表される化合物を、特開２００６−２５７０７８号公報に記載された方法で合成した。
式（Ｂ４−２−１）で表される塩１９．９２部、式（Ｂ４−２−２）で表される化合物６．０６部及びモノクロロベンゼン１００部を反応器に仕込み、２３℃で３０分間攪拌した。その後、トリフルオロ酢酸１．４９部を添加し、反応溶液が還流するまで昇温（１２５℃程度）し、還流下で２時間攪拌した。得られた反応混合物を濃縮し、得られた濃縮物に、クロロホルム２１５．１０部及びイオン交換水７１．７０部を加え、２３℃で３０分間攪拌した。その後、静置・分液し、有機層を回収した。回収された有機層に、イオン交換水７１．７０部を添加し、２３℃で３０分間攪拌し、静置・分液するという水洗操作を６回繰り返した。得られた有機層に活性炭２．４５部を仕込み、２３℃で３０分間攪拌し、ろ過した。ろ液を濃縮し、得られた濃縮物に、アセトニトリル５１．７５部を添加して溶解し、濃縮した。次に、ｔｅｒｔ−ブチルメチルエーテル１２９．３０部を加えて攪拌し、上澄液を除去し、濃縮した。続いて、得られた濃縮物に、アセトニトリル４０部を添加して溶解し、濃縮した。酢酸エチル１３１．０５部を加えて攪拌し、上澄液を除去した。最後に、得られた濃縮物に、アセトニトリル３０部を添加して溶解し、濃縮した。濃縮物に、ｔｅｒｔ−ブチルメチルエーテル７８．６３部を加えて攪拌した後、析出物をろ過することにより、式（Ｂ４−２−３）で表される塩１５．２５部を得た。 Synthesis Example 2 (salt (B4); synthesis of B4-2)

The compound represented by the formula (B4-2-1) was synthesized by the method described in JP-A-2006-257078.
19.92 parts of the salt represented by the formula (B4-2-1), 6.06 parts of the compound represented by the formula (B4-2-2) and 100 parts of monochlorobenzene were charged into the reactor, and the mixture was stirred at 23 ° C. for 30 minutes. Stir for minutes. Thereafter, 1.49 parts of trifluoroacetic acid was added, the temperature was raised until the reaction solution was refluxed (about 125 ° C.), and the mixture was stirred for 2 hours under reflux. The obtained reaction mixture was concentrated, and 215.10 parts of chloroform and 71.70 parts of ion-exchanged water were added to the resulting concentrate, followed by stirring at 23 ° C. for 30 minutes. Then, it left still and liquid-separated and collect | recovered organic layers. 71.70 parts of ion-exchanged water was added to the collected organic layer, and the water washing operation of stirring at 23 ° C. for 30 minutes, standing and separating was repeated 6 times. The obtained organic layer was charged with 2.45 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 51.75 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. Next, 129.30 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. Subsequently, 40 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. 131.05 parts of ethyl acetate was added and stirred, and the supernatant was removed. Finally, 30 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To the concentrate, 78.63 parts of tert-butyl methyl ether was added and stirred, and then the precipitate was filtered to obtain 15.25 parts of the salt represented by the formula (B4-2-3).

式（Ｂ４−２−３）で表される塩１．００部、ジメチルホルムアミド１０部及び式（Ｂ４−２−４）で表される化合物０．４０部を反応器に仕込み、２３℃で３０分間攪拌した。続いて、炭酸カリウム０．１１部及びヨウ化カリウム０．０３部を添加し、１００℃程度まで昇温した後、同温度で１２時間攪拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム１１５．３８部及び１％シュウ酸水溶液５７．６９部を加え、２３℃で３０分間攪拌した。その後、静置・分液し、有機層を回収した。回収された有機層に、イオン交換水５７．６９部を仕込み２３℃で３０分間攪拌した後、静置・分液するという水洗操作を５回繰り返した。得られた有機層に活性炭１．１９部を仕込み、２３℃で３０分間攪拌し、ろ過した。ろ液を濃縮した。得られた濃縮物に、ｔｅｒｔ−ブチルメチルエーテル１２．５０部を加えて攪拌し、上澄液を除去した。次に、得られた濃縮物に、アセトニトリル１０部を添加して溶解し、濃縮した。得られた濃縮物に、酢酸エチル１０．１０部を加えて、２３℃で１２時間攪拌した後、析出物をろ過することにより、式（Ｂ４−２）で表される塩０．５９部を得た。これをＢ４−２とする。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ６６３．３

1.00 part of a salt represented by the formula (B4-2-3), 10 parts of dimethylformamide and 0.40 part of a compound represented by the formula (B4-2-4) were charged into a reactor, and the mixture was stirred at 23 ° C. for 30 parts. Stir for minutes. Subsequently, 0.11 part of potassium carbonate and 0.03 part of potassium iodide were added, the temperature was raised to about 100 ° C., and the mixture was stirred at the same temperature for 12 hours. The obtained reaction mixture was cooled to 23 ° C., 115.38 parts of chloroform and 57.69 parts of 1% oxalic acid aqueous solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated and collect | recovered organic layers. The recovered organic layer was charged with 57.69 parts of ion-exchanged water and stirred at 23 ° C. for 30 minutes, and then the water washing operation of standing and separating was repeated 5 times. The obtained organic layer was charged with 1.19 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated. To the obtained concentrate, 12.50 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. Next, 10 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To the obtained concentrate, 10.10 parts of ethyl acetate was added and stirred at 23 ° C. for 12 hours, and then the precipitate was filtered to obtain 0.59 parts of the salt represented by the formula (B4-2). Obtained. This is B4-2.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ^- 6633.3

式（Ｂ４−３）で表される塩を、特開２００８−６９１４６号公報に記載された方法で合成した。これをＢ４−３とする。 Synthesis Example 3 (salt (B4); synthesis of B4-3)

A salt represented by the formula (B4-3) was synthesized by the method described in JP-A-2008-69146. This is designated as B4-3.

式（Ｂ４−１−４）で表される化合物を、特開２００８−１２７３６７号公報に記載された方法で合成した。
式（Ｂ４−１−４）で表される化合物２．９９部及びアセトニトリル１５．００部を反応器に仕込み、２３℃で３０分間攪拌した後、式（ＩＩＩ）で表される化合物１．３０部を添加した。その後、７０℃まで昇温し、同温度で２時間攪拌した。得られた反応混合物を２３℃まで冷却した後、不溶物をろ過により除去し、式（ＩＩＩ−１）で表される化合物を含む溶液を得た。
かくして得られた式（ＩＩＩ−１）で表される化合物を含む溶液に、式（Ｂ４−４−１）で表される化合物９．１９部を加え、２３℃で１時間攪拌した。得られた反応混合物に、クロロホルム１００部及びイオン交換水５０部を仕込み、攪拌・静置・分液を行った。回収された有機層に、イオン交換水５０部を仕込み、攪拌・静置・分液するという水洗操作を５回繰り返した。得られた有機層に活性炭１．００部を仕込み、２３℃で３０分間攪拌し、ろ過した。ろ液を濃縮した後、得られた濃縮物に、アセトニトリル５０部を添加して溶解し、濃縮した。次に、得られた濃縮物に、酢酸エチル５０部を加えて攪拌し、上澄液を除去した。続いて、得られた濃縮物にｔｅｒｔ−ブチルメチルエーテル５０部を加えて攪拌し、上澄液を除去した。最後に、得られた濃縮物をクロロホルムに溶解し、濃縮した。得られた濃縮物を、カラム分取（固定相：メルク製シリカゲル６０−２００メッシュ 展開溶媒：クロロホルム／メタノール＝５／１（体積比））することにより、式（Ｂ４−４）で表される塩１６．８４部を得た。これをＢ４−４とする。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ５５９．２ Synthesis Example 4 (salt (B4); synthesis of B4-4)

The compound represented by the formula (B4-1-4) was synthesized by the method described in JP2008-127367A.
2.99 parts of the compound represented by the formula (B4-1-4) and 15.00 parts of acetonitrile were charged into a reactor, stirred at 23 ° C. for 30 minutes, and then the compound 1.30 represented by the formula (III). Parts were added. Then, it heated up to 70 degreeC and stirred at the same temperature for 2 hours. After cooling the obtained reaction mixture to 23 ° C., insoluble matters were removed by filtration to obtain a solution containing the compound represented by the formula (III-1).
To the solution containing the compound represented by the formula (III-1) thus obtained, 9.19 parts of the compound represented by the formula (B4-4-1) was added and stirred at 23 ° C. for 1 hour. To the obtained reaction mixture, 100 parts of chloroform and 50 parts of ion-exchanged water were added, and stirring, standing, and liquid separation were performed. The recovered organic layer was charged with 50 parts of ion exchanged water, and the water washing operation of stirring, standing, and separating was repeated 5 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. After the filtrate was concentrated, 50 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. Next, 50 parts of ethyl acetate was added to the resulting concentrate and stirred, and the supernatant was removed. Subsequently, 50 parts of tert-butyl methyl ether was added to the obtained concentrate and stirred, and the supernatant was removed. Finally, the obtained concentrate was dissolved in chloroform and concentrated. The obtained concentrate is subjected to column fractionation (stationary phase: Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1 (volume ratio)), and expressed by the formula (B4-4). 16.84 parts of salt were obtained. This is B4-4.
MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 559.2

式（Ｂ４−５）で表される塩を、特開２０１１−１２６８６９号公報に記載された方法で合成した。これをＢ４−５とする。 Synthesis Example 5 (Salt (B4); Synthesis of B4-5)

A salt represented by the formula (B4-5) was synthesized by the method described in JP2011-126869A. This is designated as B4-5.

式（Ｂ４−６）で表される塩を、特開２０１１−４６６９４号公報に記載された方法で合成した。これをＢ４−６とする。 Synthesis Example 6 (salt (B4); synthesis of B4-6)

A salt represented by the formula (B4-6) was synthesized by the method described in JP2011-46694A. This is designated as B4-6.

式（Ｅ１−１−１）で表される化合物２．５０部、トリエチルアミン２．９４部及びテトラヒドロフラン１２．５０部を反応器に仕込み、２３℃で３０分間攪拌した。得られた混合液に、式（Ｅ１−１−２）で表される化合物５．２９部及びテトラヒドロフラン５．２９部の混合溶液を２３℃で１０分かけて滴下し、さらに、２３℃で１２時間攪拌した。得られた反応混合物を濃縮し、得られた濃縮物に、酢酸エチル２５部及びイオン交換水８．３３部を加えて２３℃で３０分間攪拌し、静置・分液して有機層を回収した。回収された有機層にイオン交換水８．３３部を添加し、攪拌・静置・分析するという水洗操作を４回繰り返した。回収された有機層を濃縮することにより、式（Ｅ１−１−３）で表される化合物４．４２部を得た。 Synthesis Example 7 (salt (E1); synthesis of E1-1)

2.50 parts of a compound represented by the formula (E1-1-1), 2.94 parts of triethylamine and 12.50 parts of tetrahydrofuran were charged into a reactor and stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, a mixed solution of 5.29 parts of the compound represented by the formula (E1-1-2) and 5.29 parts of tetrahydrofuran was added dropwise at 23 ° C. over 10 minutes, and further, 12 ° C. at 23 ° C. Stir for hours. The obtained reaction mixture is concentrated, and 25 parts of ethyl acetate and 8.33 parts of ion-exchanged water are added to the obtained concentrate, and the mixture is stirred at 23 ° C. for 30 minutes, allowed to stand and liquid-separated to recover the organic layer. did. The water washing operation of adding 8.33 parts of ion-exchanged water to the recovered organic layer and stirring, standing, and analyzing was repeated four times. The recovered organic layer was concentrated to obtain 4.42 parts of a compound represented by the formula (E1-1-3).

式（Ｅ１−１−４）で表される化合物２．９６部、（Ｅ１−１−３）で表される化合物０．８２部及びモノクロロベンゼン２４．００部を反応器に仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．０３部を添加し、温度を９５℃程度まで昇温した後、同温度で３０分間攪拌した。得られた反応混合物を、２３℃まで冷却し、クロロホルム４５部及びイオン交換水１１．２５部を加えて２３℃で３０分間攪拌し、静置・分液して有機層を回収した。回収された有機層にイオン交換水１１．２５部を加え、攪拌・静置・分析するという水洗操作を７回繰り返した。回収した有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ−ブチルメチルエーテル３０．６０部を加えて２３℃で３０分間攪拌した。析出物をろ過することにより、式（Ｅ１−１）で表される塩１．８６部を得た。これをＥ１−１とする。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３３６．２
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１

A reactor was charged with 2.96 parts of a compound represented by the formula (E1-1-4), 0.82 parts of a compound represented by (E1-1-3) and 24.00 parts of monochlorobenzene at 23 ° C. Stir for 30 minutes. To the resulting mixture, 0.03 part of copper (II) dibenzoate was added and the temperature was raised to about 95 ° C., followed by stirring at the same temperature for 30 minutes. The obtained reaction mixture was cooled to 23 ° C., 45 parts of chloroform and 11.25 parts of ion-exchanged water were added, stirred at 23 ° C. for 30 minutes, allowed to stand and liquid-separated to recover the organic layer. The washing operation of adding 11.25 parts of ion-exchanged water to the recovered organic layer and stirring, standing, and analyzing was repeated 7 times. The collected organic layer was concentrated, 30.60 parts of tert-butyl methyl ether was added to the resulting concentrate, and the mixture was stirred at 23 ° C. for 30 minutes. By filtering the precipitate, 1.86 parts of the salt represented by the formula (E1-1) was obtained. This is E1-1.
MASS (ESI (+) Spectrum): M ⁺ 336.2
MASS (ESI (−) Spectrum): M ^- 339.1

式（Ｅ１−１）で表される化合物１．００部及びアセトニトリル５．００部を反応器に仕込み、２３℃で３０分間攪拌した。得られた混合液に、１Ｎ塩酸１．００部を添加し、さらに、２３℃で１２時間攪拌した。得られた反応混合物を濃縮し、クロロホルム５部、イオン交換水１．２５部及び２８％アンモニア水０．３部を加えて２３℃で３０分間攪拌し、静置・分液して有機層を回収した。回収された有機層に、イオン交換水１．２５部を加えて２３℃で３０分間攪拌・静置・分液するという水洗操作を１０回繰り返した。得られた有機層を濃縮することにより、式（Ｅ１−２）で表される塩０．６８部を得た。これをＥ１−２とする。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２３６．２
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１ Synthesis Example 8 (Salt (E1); Synthesis of E1-2)

1.00 parts of the compound represented by the formula (E1-1) and 5.00 parts of acetonitrile were charged into a reactor and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 1.00 part of 1N hydrochloric acid was added, and the mixture was further stirred at 23 ° C. for 12 hours. The obtained reaction mixture was concentrated, 5 parts of chloroform, 1.25 parts of ion exchanged water and 0.3 part of 28% ammonia water were added, stirred at 23 ° C. for 30 minutes, allowed to stand and liquid-separated, and the organic layer was separated. It was collected. To the collected organic layer, 1.25 parts of ion-exchanged water was added, and the water washing operation of stirring, standing, and separating for 30 minutes at 23 ° C. was repeated 10 times. By concentrating the obtained organic layer, 0.68 parts of the salt represented by the formula (E1-2) was obtained. This is E1-2.
MASS (ESI (+) Spectrum): M ⁺ 236.2
MASS (ESI (−) Spectrum): M ^- 339.1

以下、これらの化合物のその式符号に応じて、「モノマーＡ」などという。 Synthesis of Resin (A) The compound (monomer) used for the synthesis of resin (A) is shown below.

Hereinafter, these compounds are referred to as “monomer A” or the like depending on their formula symbols.

Synthesis Example 9 [Synthesis of Resin A1-1]
In a four-necked flask equipped with a condenser and a stirrer, 72.58 parts of dioxane, 16.0 parts of monomer B, 5.59 parts of monomer C, 2.88 parts of monomer D, 6.92 parts of monomer E, and 17.09 parts of monomer F [molar ratio] Monomer B: monomer C: monomer D: monomer E: monomer F = 30: 14: 6: 20: 30]. To this solution, 0.33 part of azobisisobutyronitrile and 1.51 part of azobis (2,4-dimethylvaleronitrile) were added as initiators and stirred at 73 ° C. for 5 hours. Thereafter, the reaction mixture was added to a mixed solution of 252 parts of methanol and 63 parts of water to precipitate the resin. The obtained resin was dissolved in 80 parts of dioxane and added to a mixed solution of 252 parts of methanol and 63 parts of water to precipitate the resin. This reprecipitation operation was performed again, and the precipitated resin was collected by filtration and further dried under reduced pressure to obtain 36.3 parts of resin A1-1 having a weight average molecular weight of 6.2 × 10 ³ . This resin A1-1 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A1-2]
13.9 parts of dioxane was charged into a four-necked flask equipped with a condenser and a stirrer, and the temperature was raised to 85 ° C. Monomer H 9.60 parts, monomer G 4.3 parts, monomer A 7.00 parts, monomer D 2.40 parts [molar ratio; monomer H: monomer A: monomer D: monomer G = 50: 30: 10: 10] and A solution prepared by dissolving 2.0 parts of azobisisobutyronitrile in 20.9 parts of dioxane was added dropwise over 1 hour. Thereafter, stirring was continued for 6 hours while maintaining 85 ° C. After cooling, this reaction mixture was added to a mixed solution of 211 parts of methanol and 90 parts of water to precipitate the resin. The obtained resin was dissolved in methyl isobutyl ketone, 0.7 parts of p-toluenesulfonic acid and 70 parts of water were added and stirred for 6 hours. Ion exchanged water was added to the reaction mixture, and the water washing operation of stirring, standing, and liquid separation was repeated 4 times, and then the recovered organic layer was poured into 300 parts of n-heptane to precipitate a resin. The precipitated resin was filtered and dried under reduced pressure to obtain 20.3 parts of a resin having a weight average molecular weight of 4.3 × 10 ³ . This resin has a structural unit of the following formula, and this is designated as resin A1-2.

Synthesis Example 11 [Synthesis of Resin A1-3]
A four-necked flask equipped with a condenser and a stirrer was charged with 18.9 parts of propylene glycol monomethyl ether acetate and heated to 85 ° C. Monomer H 15.0 parts, monomer J 5.81 parts, monomer K 7.31 parts, monomer L 1.37 parts, monomer I 1.63 parts [molar ratio; monomer H: monomer J: monomer K: monomer L: monomer I = 50: 15: 20: 5: 10] and a solution of 1.15 parts of azobis-2,4-dimethylvaleronitrile in 28.3 parts of propylene glycol monomethyl ether acetate was added dropwise over 2 hours. Thereafter, stirring was continued for 6 hours while maintaining 85 ° C. The reaction solution was cooled to 40 ° C. A mixed solution of 327 parts of methanol and 82 parts of water was cooled to 10 ° C., and the reaction solution was poured therein to precipitate the resin. The resin collected by filtration was dissolved in 94 parts of methyl isobutyl ketone, and 0.63 part of p-toluenesulfonic acid and 63.0 parts of water were added and stirred for 6 hours. The organic layer recovered by standing and liquid separation was washed with water about three times, and then the washed organic layer was poured into 409 parts of n-heptane to precipitate a resin. The precipitated resin was collected by filtration and further dried under reduced pressure to obtain 22.8 parts of Resin A1-3 having a weight average molecular weight of 7.6 × 10 ³ . This resin A1-3 has the following structural units.

Synthesis Example 12 [Synthesis of Resin A1-4]
A four-necked flask equipped with a condenser and a stirrer was charged with 18.9 parts of propylene glycol monomethyl ether acetate and 4.00 parts of monomer B, and the temperature was raised to 75 ° C. There, monomer B12.0 parts, monomer M5.50 parts, monomer D2.57 parts, monomer F12.2 parts, monomer E11.8 parts [molar ratio; monomer B: monomer M: monomer D: monomer F: monomer E = 28: 15: 5: 20: 32], 0.61 part of azobis-2,4-dimethylvaleronitrile and 2.76 parts of azobis-2,4-dimethylvaleronitrile to 57.8 parts of propylene glycol monomethyl ether acetate. The dissolved solution was added dropwise over 1 hour. Thereafter, stirring was continued for 5 hours while maintaining 75 ° C. The reaction solution was cooled to 40 ° C. A mixed solution of 594 parts of methanol and 31 parts of water was cooled to 10 ° C., and the reaction solution was poured therein to precipitate a resin. The resin collected by filtration was added to 313 parts of methanol, and the repulping operation was performed three times. The obtained resin was collected by filtration and dried under reduced pressure to obtain 36.2 parts of a resin A1-4 having a weight average molecular weight of 7.5 × 10 ³ . This resin A1-4 has the following structural units.

Examples 1 to 15 and Comparative Example 1
(Preparation of resist composition)
Each component shown in Table 1 was mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Acid generator>
B4-1: B4-1 obtained in Synthesis Example 1
B4-2: B4-2 obtained in Synthesis Example 2
B4-3: B4-3 obtained in Synthesis Example 3
B4-4: B4-4 obtained in Synthesis Example 4
B4-5: B4-5 obtained in Synthesis Example 5
B4-6: B4-6 obtained in Synthesis Example 6
E1-1: E1-1 obtained in Synthesis Example 7
E1-2: E1-2 obtained in Synthesis Example 8
<Resin (A)>
A1-1: A1-1 obtained in Synthesis Example 9
A1-2: A1-2 obtained in Synthesis Example 10
A1-3: A1-3 obtained in Synthesis Example 11
A1-4: A1-4 obtained in Synthesis Example 12
<Basic compound (C)>
Basic compound C1: tetrabutylammonium hydroxide <solvent (D)>
Propylene glycol monomethyl ether acetate 400.0 parts Propylene glycol monomethyl ether 100.0 parts γ-butyrolactone 5.0 parts

(Evaluation as a resist composition for electron beams)
The silicon wafer was processed at 90 ° C. for 60 seconds using hexamethyldisilazane on a direct hot plate. This silicon wafer was spin-coated with a resist composition so that the thickness of the dried composition layer was 0.06 μm. Then, it prebaked for 60 seconds on the direct hot plate at the temperature shown in the "PB" column of Table 1. Each wafer on which the composition layer was formed was exposed to a line-and-space pattern using an electron beam drawing machine ["HL-800D 50 keV" manufactured by Hitachi, Ltd.] with the exposure amount being changed stepwise.
After the exposure, post-exposure baking was performed for 60 seconds at the temperature shown in the “PEB” column of Table 1 on a hot plate, and paddle development was further performed for 60 seconds with a 2.38 wt% tetramethylammonium hydroxide aqueous solution.
The developed pattern on the silicon substrate was observed with a scanning electron microscope.

Line Edge Roughness Evaluation (LER): The wall surface of the resist pattern produced by exposing with an exposure amount at which an 80 nm line and space pattern is 1: 1 was observed with a scanning electron microscope to obtain line edge roughness. The results are shown in Table 2.

Example 16
The same resist composition prepared in Example 1 was used for evaluation as a resist composition for EUV.

(Evaluation as a resist composition for EUV)
The silicon wafer was processed at 90 ° C. for 60 seconds using hexamethyldisilazane on a direct hot plate. The silicon wafer was spin-coated with the resist composition of Example 1 so that the thickness of the composition layer after drying was 0.05 μm.
Then, it prebaked for 60 seconds on the direct hot plate at the temperature shown in the "PB" column of Table 1. The wafer on which the composition layer was formed was exposed to a line and space pattern using an EUV exposure machine while changing the exposure amount stepwise.
After the exposure, post-exposure baking was performed for 60 seconds at the temperature shown in the “PEB” column of Table 1 on a hot plate, and paddle development was further performed for 60 seconds with a 2.38 wt% tetramethylammonium hydroxide aqueous solution.

Line Edge Roughness Evaluation (LER): The wall surface of the resist pattern after the lithography process exposed with an exposure amount at which a 50 nm line and space pattern is 1: 1 was observed with a scanning electron microscope to obtain line edge roughness. The results are shown in Table 3.

  If the resist composition of this invention is used, the resist pattern which has the outstanding line edge roughness (LER) can be manufactured. Therefore, the resist composition of the present invention is extremely useful for fine processing of semiconductors.

Claims (8)

A resin (A) having an acid-decomposable group;
Formula (B4)

[In the formula (B4),
A ⁺ represents an acid-decomposable group and an organic cation having no nitrogen atom.
X _a ^- has an acid-decomposable group, it represents an organic sulfonate anion having no nitrogen atom. ]
A salt (B) represented by:
Formula (E1)

[In the formula (E1),
A _N represents an organic cation having a nitrogen atom.
X ^- represents an organic sulfonate anion having no nitrogen atom. ]
The resist composition containing the salt (E1) represented by these. A ^{+ in the} formula (B4) is an organic sulfonium cation having no acid-decomposable group and a nitrogen atom, and A _N ^{+ in the} formula (E1) is an organic sulfonium cation having a nitrogen atom. The resist composition as described. The resist composition according to claim 1, wherein X _a ^{− in the} formula (B4) is an organic sulfonate anion represented by the formula (b4-1) or (b4-2).

[In the formula (b4-1),
^Xb1 represents an acid-decomposable group having no nitrogen atom.
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent linking group having no nitrogen atom. ]

[In the formula (b4-2)
^Xb represents an acid-decomposable group having no nitrogen atom.
m4 represents an integer of 1 or 2, and when m4 is 2, two existing ^Xb are the same or different. ] The resist composition according to claim 3, wherein the organic sulfonate anion represented by the formula (b4-1) is an organic sulfonate anion represented by the formula (b4-1-A).

[In the formula (b4-1-A),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^{b1 ″} and L ^{b1 ′} each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic hydrocarbon group is , Oxygen atom or carbonyl group may be substituted.
Y ^b1 represents a phenylene group or a single bond that may have an alkyl group having 1 to 5 carbon atoms.
^Xb represents an acid-decomposable group having no nitrogen atom. ] The A _N ^{+ in the} formula (E1) is an organic cation represented by any one of the formula (e1-1), the formula (e1-2), and the formula (e1-3). The resist composition as described.

[In the formula (e1-1),
R ^e1 and R ^e2 each independently represent a hydrogen atom, a halogen atom, a hydroxy group, a cyano group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an acyl group having 2 to 5 carbon atoms. .
In formula (e1-2),
R ^e3 represents a hydroxy group or an alkyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkyl group may be replaced with an oxygen atom or a carbonyl group.
R ^e4 and R ^e6 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
m7 represents an integer of 0 to 3. m8 and m9 each independently represent 1 or 2.
When m7 is 2 or 3, a plurality of R ^e3 are the same or different.
When m8 is 2, two R ^e4 are the same or different.
When m9 is 2, two R ^e6 are the same or different.
R ^e5 represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkyl group may be replaced with an oxygen atom or a carbonyl group.
m10 represents 0 or 1. ]
In formula (e1-3),
R ^e7 , R ^e8 and R ^e9 (R ^{e7 to} R ^e9 ) are each independently an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic group having 6 to 18 carbon atoms. Hydrocarbon group or formula (e1-4)

(In the formula (e1-4),
R ^e10 and R ^e11 each independently represent an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R ^e10 and R ^e11 may be bonded to each other and form a ring together with the nitrogen atom to which they are bonded.
The hydrogen atom contained in the alkyl group, alicyclic hydrocarbon group and aromatic hydrocarbon group is a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an alicyclic group having 3 to 18 carbon atoms. It may be substituted with a hydrocarbon group.
L ^e1 represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms, and the methylene group constituting the divalent aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. )
And at least one of R ^{e7 to} R ^e9 is a group represented by the formula (e1-4). The hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group is a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an aliphatic group having 3 to 18 carbon atoms. It may be substituted with a cyclic hydrocarbon group. ]   The resist composition according to any one of claims 1 to 5, wherein the content mass of the salt (B4) is larger than the content mass of the salt (E1). The resin (A) is
The resist composition according to claim 1, which is a resin having a structural unit represented by formula (a1-1) or a structural unit represented by formula (a1-2).

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to a carbonyl group. Represent.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ] (1) The process of apply | coating the resist composition in any one of Claims 1-7 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A step of heating the composition layer after exposure,
(5) a step of developing the composition layer after heating;
A method for producing a resist pattern including: