JP2013033230A - 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 with better line edge roughness (LER) can be produced.SOLUTION: The resist composition contains: a resin (A) having an acid decomposable group; a salt (B3) expressed by formula (B3); and a salt (E2) expressed by formula (E2). In formula (B3), Arepresents an organic cation having an acid decomposable group and no nitrogen atom. In formula (E2), Arepresents an organic cation having no nitrogen atom; and Xrepresents an organic sulfonic acid anion having a 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（酸分解性基を有する塩）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、溶剤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 salt having an acid-decomposable group);
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 and a solvent is described.

JP 2011-6400 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 order to produce such a resist pattern, the resist composition described in Patent Document 1 still has room for improvement.

［式（Ｂ３）中、
Ａ_ａ ^＋は、酸分解性基を有し、窒素原子を有さない有機カチオンを表す。
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は、炭素数１〜５のアルカンジイル基を表す。
Ｙは、炭素数３〜１８の脂環式炭化水素基を表し、該脂環式炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよく、
該脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１〜１２のアルコキシ基、炭素数６〜１８の芳香族炭化水素基、炭素数７〜２１のアラルキル基、炭素数２〜４のアシル基、グリシジルオキシ基又は−（ＣＨ₂）_j2−Ｏ−ＣＯ−Ｒ^b1（式中、Ｒ^b1は、炭素数１〜１６のアルキル基、炭素数３〜１６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。ｊ２は、０〜４の整数を表す。）
で表される基に置換されてもよい。］
で表される塩（Ｂ３）と、
式（Ｅ２）

［式（Ｅ２）中、
Ａ^＋は、窒素原子を有さない有機カチオンを表す。
Ｘ_Ｎ ⁻は、窒素原子を有する有機スルホン酸アニオンを表す。］
で表される塩（Ｅ２）と
を含有するレジスト組成物。
〔２〕 前記式（Ｂ３）のＡ_ａ ^＋が酸分解性基を有し、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（Ｅ２）のＡ^＋が、窒素原子を有さない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（Ｂ３）のＡ_ａ ^＋が、式（ｂ３−１）表される有機カチオンである〔１〕又は〔２〕記載のレジスト組成物。

［式（ｂ３−１）中、
Ｒ^ｄ１、Ｒ^ｄ２及びＲ^ｄ３（Ｒ^ｄ１〜Ｒ^ｄ３）はそれぞれ独立に、窒素原子を有さない置換基を有してもよい炭素数１〜３０の炭化水素基を表す。ただし、Ｒ^ｄ１〜Ｒ^ｄ３のうち少なくとも１つは、式（ｂ３−１−１）

（式（ｂ３−１−１）中、
Ｒ^ｄ４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。
Ｒ^ｄ５は、炭素数１〜５のアルキル基を表す。
ｍ３は０〜２の整数を表し、ｍ３が２である場合、２つ存在するＲ^ｄ５は同一又は相異なる。
Ｘ^ｂは、酸の作用により分解する基を表す。
＊は硫黄原子との結合手を表す。）
で表される基である。
Ｒ^ｄ１〜Ｒ^ｄ３のうち１つが、式（ｂ３−１−１）で表される基である場合、残りの２つが互いに結合し、これらが結合する硫黄原子とともに環を形成してもよい。］
〔４〕 Ｒ^ｄ１、Ｒ^ｄ２及びＲ^ｄ３が、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（ｂ３−１−１）で表される基を表し、該アルキル基に含まれる水素原子は、ヒドロキシ基、炭素数１〜１２のアルコキシ基又は炭素数３〜１８の脂環式炭化水素基に置換されていてもよく、該脂環式炭化水素基に含まれる水素原子は、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炭素数３〜１８の脂環式炭化水素基に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、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炭素数３〜１８の脂環式炭化水素基に置換されていてもよい〔３〕に記載のレジスト組成物。
〔５〕 前記式（Ｅ２）のＸ_Ｎ ⁻が、式（ｅ２−１）又は式（ｅ２−２）で表される有機スルホン酸アニオンである〔１〕〜〔４〕のいずれか記載のレジスト組成物。

［式（ｅ２−１）及び式（ｅ２−２）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^ｅ２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^Ｎは窒素原子を含む有機基である。］
〔６〕 前記塩（Ｂ）の含有質量が、前記塩（Ｅ２）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 (B3)

[In the formula (B3),
A _a ⁺ represents an organic cation having an acid-decomposable group and having no nitrogen atom.
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L represents an alkanediyl group having 1 to 5 carbon atoms.
Y represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group may be replaced by an oxygen atom, a sulfonyl group or a carbonyl group,
The hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, An acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or — (CH ₂ ) _j2 —O—CO—R ^b1 (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, and an oil having 3 to 16 carbon atoms Represents a cyclic hydrocarbon group or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4)
It may be substituted with a group represented by ]
A salt (B3) represented by:
Formula (E2)

[In the formula (E2),
A ⁺ represents an organic cation having no nitrogen atom.
X _N ⁻ represents an organic sulfonate anion having a nitrogen atom. ]
The resist composition containing the salt (E2) represented by these.
[2] A _a ^{+ in the} formula (B3) is an organic sulfonium cation having an acid-decomposable group and not having a nitrogen atom, and A ^{+ in the} formula (E2) is an organic having no nitrogen atom. [1] The resist composition according to [1], which is a sulfonium cation.
[3] The resist composition according to [1] or [2], wherein A _a ⁺ in the formula (B3) is an organic cation represented by the formula (b3-1).

[In the formula (b3-1),
R ^d1 , R ^d2 and R ^d3 (R ^{d1 to} R ^d3 ) each independently represent a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent not having a nitrogen atom. However, at least one of R ^{d1 to} R ^d3 has the formula (b3-1-1)

(In the formula (b3-1-1),
R ^d4 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.
R ^d5 represents an alkyl group having 1 to 5 carbon atoms.
m3 represents an integer of 0 to 2, and when m3 is 2, two R ^d5 present are the same or different.
^Xb represents a group that is decomposed by the action of an acid.
* Represents a bond with a sulfur atom. )
It is group represented by these.
When one of R ^{d1 to} R ^d3 is a group represented by the formula (b3-1-1), the remaining two may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. ]
[4] R ^d1 , R ^d2 and R ^d3 are each independently 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. Or a group represented by the formula (b3-1-1), and the hydrogen atom contained in the alkyl group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon having 3 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or a carbon atom having 3 to 18 carbon atoms. The hydrogen atom contained in the aromatic hydrocarbon group which may be substituted with an alicyclic 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 a carbon number. It may be substituted with 3 to 18 alicyclic hydrocarbon groups [ The resist composition according to].
[5] _{X N} of the formula (E2) ^- the resist according to any one of formulas (E2-1) or an organic sulfonic acid anion represented by the formula (E2-2) [1] to [4] Composition.

[In Formula (e2-1) and Formula (e2-2),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
^Le2 represents 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 may be replaced with an oxygen atom or a carbonyl group. Good.
Y ^N is an organic group containing a nitrogen atom. ]
[6] The resist composition according to any one of [1] to [5], wherein the contained mass of the salt (B) is larger than the contained mass of the salt (E2).
[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 (B3) represented by the formula (B3) [hereinafter referred to as “salt (B3)” in some cases. ] And a salt (E2) represented by the formula (E2) [hereinafter referred to as “salt (E2)” 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（Ｂ３）中、
Ａ_ａ ^＋は、酸分解性基を有し、窒素原子を有さない有機カチオンを表す。
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は、炭素数１〜５のアルカンジイル基を表す。
Ｙは、炭素数３〜１８の脂環式炭化水素基を表し、該脂環式炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよく、
該脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１〜１２のアルキル基、炭素数１〜１２のヒドロキシ基含有アルキル基、炭素数１〜１２のアルコキシ基、炭素数６〜１８の芳香族炭化水素基、炭素数７〜２１のアラルキル基、炭素数２〜４のアシル基、グリシジルオキシ基又は−（ＣＨ₂）_j2−Ｏ−ＣＯ−Ｒ^b1（式中、Ｒ^b1は、炭素数１〜１６のアルキル基、炭素数３〜１６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。ｊ２は、０〜４の整数を表す。）
で表される基に置換されてもよい。］ <Salt (B3)>
The salt (B3) is represented by the following formula (B3).

[In the formula (B3),
A _a ⁺ represents an organic cation having an acid-decomposable group and having no nitrogen atom.
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L represents an alkanediyl group having 1 to 5 carbon atoms.
Y represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group may be replaced by an oxygen atom, a sulfonyl group or a carbonyl group,
The hydrogen atom contained in the alicyclic hydrocarbon group is 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, an alkoxy group having 1 to 12 carbon atoms, An aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or — (CH ₂ ) _{j 2} —O—CO—R ^b1 (wherein , R ^b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4; Represents.)
It may be substituted with a group represented by ]

The acid-decomposable group possessed by A _a ⁺ means a group that can be decomposed by the action of an acid, and preferably a group that can be decomposed 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.

A _a ⁺ is an acid-decomposable group, preferably an acid-decomposable group (1) or an acid-decomposable group (2), and is an organic cation that is positively charged and does not have a nitrogen atom. A cation, and such an organic cation (A _a ⁺ ) is an organic sulfonium cation, an organic iodonium cation, a benzothiazolium cation, an organic phosphonium cation, or the like, preferably an organic sulfonium cation or an organic iodonium cation, More preferably, it is an organic sulfonium cation. 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（ｂ３−１）中、
Ｒ^ｄ１、Ｒ^ｄ２及びＲ^ｄ３（Ｒ^ｄ１〜Ｒ^ｄ３）はそれぞれ独立に、窒素原子を有さない置換基を有してもよい炭素数１〜３０の炭化水素基を表す。ただし、Ｒ^ｄ１〜Ｒ^ｄ３のうち少なくとも１つは、式（ｂ３−１−１）

（式（ｂ３−１−１）中、
Ｒ^ｄ４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。
Ｒ^ｄ５は、炭素数１〜５のアルキル基を表す。
ｍ３は０〜２の整数を表し、ｍ３が２である場合、２つ存在するＲ^ｄ５は同一又は相異なる。
Ｘ^ｂは、酸分解性基を表す。
＊は硫黄原子との結合手を表す。）
で表される基である。
Ｒ^ｄ１〜Ｒ^ｄ３のうち１つが、式（ｂ３−１−１）で表される基である場合、残りの２つが互いに結合し、これらが結合する硫黄原子とともに環を形成してもよい。］ Specifically, _a particularly preferred organic cation (A _a ⁺ ) is specifically shown as an organic cation represented by the following formula (b3-1) [hereinafter referred to as “cation (b3-1)” in some cases. ] Can be mentioned.

[In the formula (b3-1),
R ^d1 , R ^d2 and R ^d3 (R ^{d1 to} R ^d3 ) each independently represent a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent not having a nitrogen atom. However, at least one of R ^{d1 to} R ^d3 has the formula (b3-1-1)

(In the formula (b3-1-1),
R ^d4 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.
R ^d5 represents an alkyl group having 1 to 5 carbon atoms.
m3 represents an integer of 0 to 2, and when m3 is 2, two R ^d5 present are the same or different.
^Xb represents an acid-decomposable group.
* Represents a bond with a sulfur atom. )
It is group represented by these.
When one of R ^{d1 to} R ^d3 is a group represented by the formula (b3-1-1), the remaining two may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. ]

R ^d1 , R ^d2 and R ^d3 are each independently an alkyl group having 1 to 30 carbon atoms (the hydrogen atom contained in the alkyl group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or 6 to 18 carbon atoms). Or an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom or 2 to 4 carbon atoms). Or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group is a halogen atom, a hydroxy group, or an alkyl group having 1 to 18 carbon atoms). And may be substituted with a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.

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。
飽和環状炭化水素基としては、前述のシクロアルキル基、デカヒドロナフチル基、アダマンチル基、ノルボルニル基、メチルノルボルニル基等が挙げられる。
Ｒ^ｄ１〜Ｒ^ｄ３のうち２つが一緒になって形成してもよい硫黄原子を含む環としては、単環式、多環式、芳香族性、非芳香族性、飽和及び不飽和のいずれの環であってもよく、硫黄原子を１以上含むものであれば、さらに、１以上の硫黄原子及び／又は１以上の酸素原子を含んでいてもよい。該環としては、炭素数３〜１８の環が好ましく、炭素数４〜１８の環がより好ましい。 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 saturated cyclic hydrocarbon group include the aforementioned cycloalkyl group, decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group and the like.
The ring containing a sulfur atom that two of R ^{d1 to} R ^d3 may form together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated. If it is a ring and contains one or more sulfur atoms, it may further contain one or more sulfur atoms and / or one or more oxygen atoms. As the ring, a ring having 3 to 18 carbon atoms is preferable, and a ring having 4 to 18 carbon atoms is more preferable.

Among the cations (b3-1), it is preferable that one of R ^{d1 to} R ^d3 is a group represented by the formula (b3-1-1). A cation (b3-1) in which one of R ^{d1 to} R ^d3 is a group represented by the formula (b3-1-1) is produced from a salt (B3) having the cation (b3-1). There is an advantage that it is easy to do. The acid-decomposable group for ^Xb is preferably the above-mentioned acid-decomposable group (1) or acid-decomposable group (2).

［式（ｂ３−１−１−１）〜（ｂ３−１−１−６）中、
Ｒ^ｄ１及びｍ３は、前記式（ｂ３−１）と同義であり、Ｒ^ａ１〜Ｒ^ａ３はいずれも、前記式（１）と同義である。］ A preferred cation (b3-1), that is, one of R ^{d1 to} R ^d3 is a group represented by the above formula (b3-1-1). Specifically, the following formula (b3- 1-1-1) to formula (b3-1-1-6). Among these, formula (b3-1-1-1) to formula (b3-1-1-3) are preferable, and formula (b3-1-1-1) is particularly preferable.

[In the formulas (b3-1-1-1) to (b3-1-1-6),
R ^d1 and m3 are synonymous with the formula (b3-1), and R ^{a1 to} R ^a3 are all synonymous with the formula (1). ]

  Then, the organic sulfonate anion which comprises salt (B3) is demonstrated. The organic sulfonate anion is an anion characterized by having neither a nitrogen atom nor an acid-decomposable group already described.

As the perfluoroalkyl group in Q ¹ and Q ² of the formula (B3), a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, Examples include perfluoropentyl group and perfluorohexyl group. Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, and more preferably when Q ¹ and Q ² are both fluorine atoms.

  L represents an alkanediyl group having 1 to 5 carbon atoms, 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, methylidene group, ethylidene group, propylidene group, 2-propylidene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2- Examples include methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group and the like.

  Examples of the alicyclic hydrocarbon group for Y include the same as those described above. Moreover, the methylene group contained in the alicyclic hydrocarbon group of Y may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group.

これらの中でも、好ましくは式（Ｙ１）〜式（Ｙ１９）のいずれかで表される基であり、より好ましくは式（Ｙ１１）、式（Ｙ１４）、式（Ｙ１５）又は式（Ｙ１９）で表される基であり、さらに好ましくは式（Ｙ１１）又は式（Ｙ１４）で表される基である。 Specific examples of Y include groups represented by formulas (Y1) to (Y26) (in the following specific examples, the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom or a carbonyl group. Or those substituted with a sulfonyl group).

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).

The alicyclic hydrocarbon group of Y may have a substituent, and as the substituent, a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms. , An aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group, and a — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is a group having 1 to 16 carbon atoms) And an alkyl group having 3 to 16 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4). When the substituent contained in the alicyclic hydrocarbon group of Y is an aromatic hydrocarbon group and an aralkyl group, the aromatic ring in the substituent may further have a substituent. Examples of the substituent here include an alkyl group, a halogen atom, and a hydroxy 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.

Examples of the alicyclic hydrocarbon group having 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). When these have a substituent, the substituent is a hydroxy group or an oxo Groups are preferred. That is, as the alicyclic hydrocarbon group having a substituent, a hydroxyadamantyl group and an oxoadamantyl group are particularly preferable as Y.

<Specific example of salt (B3)>
The salt (B3) is an arbitrary combination of the above-described organic cation (A _a ⁺ ) and the above-described organic sulfonate anion (X ⁻ ). Specific examples include the following salts.

By using the salt (B3) in the resist composition of the present invention in combination with the salt (E1) described later, it is possible to produce a resist pattern having excellent line edge roughness. Among them, the salt (B3) is preferably composed of an organic cation represented by the formula (b3-1-1-1) and an organic sulfonate anion (X ⁻ ). It can be manufactured by the manufacturing method described in Patent Document 1.

［式（Ｅ２）中、
Ａ^＋は、窒素原子を有さない有機カチオンを表す。
Ｘ_Ｎ ⁻は、窒素原子を有する有機スルホン酸アニオンを表す。］ <Salt (E2)>
The salt (E2) is represented by the following formula (E2).

[In the formula (E2),
A ⁺ represents an organic cation having no nitrogen atom.
X _N ⁻ represents an organic sulfonate anion having a nitrogen atom. ]

In the formula (E2), the organic cation (A ⁺ ) does not have a nitrogen atom. It may or may not have an acid-decomposable group. 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.

The organic cation (A ⁺ ) in the formula (E2) is preferably the formula (b2-1), the formula (b2-2), the formula (b2-3) and the formula (b2-4) [formula (b2-1). To a cation [sulfonium cation or iodonium cation] represented by any one of formulas (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, and 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 alkyl group may have a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon group includes a halogen atom and a carbon number. It may have 2 to 4 acyl groups or glycidyloxy groups, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms, or a saturated cyclic carbonization having 3 to 18 carbon atoms. You may have a hydrogen group or a C1-C12 alkoxy group.

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. 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, and 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 when a plurality of R ^b17 are identical or different and from each other, if u2 is an integer of 2 or more, plural R ^b18 are identical or different from each other. When q2 is an integer of 2 or more, the plurality of R ^b15 are the same or different from each other. When r2 is an integer of 2 or more, the plurality of R ^b16 are the same or different from each other.

The alkylcarbonyloxy group for R ^b12 is a group in which the acyl group already exemplified and an oxygen atom 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の脂肪族炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
この脂肪族炭化水素基の炭素数は１〜１２の範囲であると好ましく、炭素数１〜１２のアルキル基及び炭素数４〜１８の脂環式炭化水素基がより好ましく、さらには置換基として、ハロゲン原子、ヒドロキシ基、炭素数１〜１２のアルコキシ基、炭素数６〜１８の芳香族炭化水素基、炭素数２〜４のアシル基又はグリシジルオキシ基を有していてもよい。
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は同一でも異なっていてもよく、ｗ２が２以上のとき、複数のＲ^b20は同一でも異なっていてもよく、ｘ２が２以上のとき、複数のＲ^b21は同一でも異なっていてもよい。
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. ], More preferably a triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0) or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = X2 = 1, and R ¹⁹ , R ²⁰ and R ²¹ are all methyl groups).

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 aliphatic hydrocarbon group having 1 to 18 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
The aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms and an alicyclic hydrocarbon group having 4 to 18 carbon atoms, and further, as a substituent. , A halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, 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, a plurality of R ^b19 may be the same or different. When w2 is 2 or more, a plurality of R ^b20 may be the same or different. When x2 is 2 or more, a plurality of R ^{b19 b21} may be 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.

式（ｅ２−１）中、
Ｑ¹及びＱ²は、前記式（Ｂ３）と同様、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、単結合又は炭素数１〜１７の２価の脂肪族飽和炭化水素基を表し、該２価の脂肪族飽和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^Ｎは窒素原子を含む有機基である。 The organic sulfonate anion (X _N ⁻ ) constituting the salt (E2) includes a nitrogen atom and a sulfonate group (—SO ₃ ⁻ ). Suitable organic sulfonate anions (X _N ⁻ ) include those represented by formula (e2-1) and formula (e2-2).

In formula (e2-1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group, as in the formula (B3).
^Le2 represents a single bond or a C1-C17 divalent aliphatic saturated hydrocarbon group, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group is replaced by an oxygen atom or a carbonyl group. May be.
Y ^N is an organic group containing a nitrogen atom.

式（ｅ２−２）中、
Ｙ^Ｎは、前記式（ｅ２−１）と同義である。

In formula (e2-2),
Y ^N is the same as defined in the formula (E2-1).

Specific examples of the perfluoroalkyl group for Q ¹ and Q ² are the same as those described above. Q ¹ and Q ² contained in the salt (B3) contained in the resist composition of the present invention are not necessarily the same as Q ¹ and Q ² contained in the salt (E2). However, Q ¹ and Q ² of the salt (E2) are preferably each independently a perfluoromethyl group or a fluorine atom, and more preferably a fluorine atom.

Aliphatic hydrocarbon group L ^e2 are methylene, ethylene, propane-1,3-diyl, 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-1,17-diyl group, methylidene group, ethylidene group, propylidene group, 2-propylidene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2- An alkanediyl group having 1 to 17 carbon atoms such as methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group, the above formula (KA-1) A group (divalent alicyclic hydrocarbon group) formed by removing two hydrogen atoms from an alicyclic hydrocarbon of formula (KA-19), these alkanediyl groups and divalent alicyclic carbonization A divalent group which is a combination with a hydrogen group can be mentioned.

式（ｂ１−１）〜式（ｂ１−７）中、
Ｌ^b2は、単結合又は炭素数１〜１５の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b3は、単結合又は炭素数１〜１２の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b4は、炭素数１〜１３の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b3及びＬ^b4の合計炭素数の上限は１３である。
Ｌ^b5は、炭素数１〜１５のの脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の脂肪族炭化水素基を表し、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b6及びＬ^b7の合計炭素数の上限は１６である。
Ｌ^b8は、炭素数１〜１４の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b9及びＬ^b10は、それぞれ独立に、炭素数１〜１１の脂肪族炭化水素基を表し、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b9及びＬ^b10の合計炭素数の上限は１２である。
Ｌ^b11は、炭素数１〜１３の脂肪族炭化水素基を表し、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。 Methylene group constituting the aliphatic hydrocarbon group of L ^e2 is, those which replaced by an oxygen atom or a carbonyl group, for example, the following formula (b1-1), the formula (b1-2), the formula (b1-3 ), Formula (b1-4), Formula (b1-5), Formula (b1-6), and Formula (b1-7) [Formula (b1-1) to Formula (b1-7)] Group. Note that in formulas (b1-1) to (b1-7), * indicates a bond, and the left bond * is bonded to a carbon atom of C (Q ¹ ) (Q ² ). The bond * is combined with Y.

In formula (b1-1) to formula (b1-7),
L ^b2 represents a single bond or an aliphatic hydrocarbon group having 1 to 15 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b3 represents a single bond or an aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b4 represents an aliphatic hydrocarbon group having 1 to 13 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents an aliphatic hydrocarbon group having 1 to 15 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b6 and L ^b7 each independently represent an aliphatic hydrocarbon group having 1 to 15 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents an aliphatic hydrocarbon group having 1 to 14 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b9 and L ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 11 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.
L ^b11 represents an aliphatic hydrocarbon group having 1 to 13 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups.

Examples of the divalent group represented by the formula (b1-1) include the following.

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

Examples of the divalent group represented by the formula (b1-3) include the following.

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

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

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

上記基において、*は結合手を示し、左側の結合手*はは、Ｃ（Ｑ¹）（Ｑ²）の炭素原子と結合し、右側の結合手*はＹと結合する。 Examples of the divalent group represented by the formula (b1-7) include the following.

In the above group, * represents a bond, the bond on the left side * is bonded to the carbon atom of C (Q ¹ ) (Q ² ), and the bond on the right side * is bonded to Y.

When the salt (E2) contained in the resist composition of the present invention has an organic sulfonate anion represented by the formula (e2-1), L ^e2 of the organic sulfonate anion is represented by the formula (b1 -1) or a divalent group represented by formula (b1-7) is preferable.

Configuration In the formula (E2-1) and formula (E2-2), as an organic group containing a nitrogen atom of ^{Y N} For example, a hydrocarbon group of 1 to 14 carbon atoms having a substituted or unsubstituted amino group, a ring A C2-C13 heterocyclic group containing a nitrogen atom as a ring atom (ring-constituting atom) (the heterocyclic ring contained in the heterocyclic group may be aromatic or non-aromatic) Good). As used herein, the term “substituted or unsubstituted amino group” means NR ^N1 R ^N2 (where R ^N1 and R ^N2 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aromatic carbon atom having 6 to 20 carbon atoms). Represents a hydrogen group or an aralkyl group having 7 to 21 carbon atoms.). When there is a methylene group constituting the hydrocarbon group, the methylene group may be replaced with an oxygen atom. The hydrogen atom contained in the heterocyclic group may be substituted with a hydroxyl group, a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.
Any organic group having more nitrogen atoms, may be selected as Y ^N, Of these, including heterocyclic groups containing a nitrogen atom as a ring-constituting atom as Y ^N, the formula (E2-1) and formula (e2 The salt (E2) composed of the organic sulfonate anion (X _N ⁻ ) represented by -2) is preferable because it can be easily produced. The heterocyclic ring contained in the heterocyclic group only needs to have at least one nitrogen atom as a ring constituent atom, and may have a plurality of nitrogen atoms as a ring constituent atom or a hetero atom other than a nitrogen atom. It may have atoms.

<Specific example of salt (E2)>
Specific examples of the salt (E2) are specifically shown as follows.

（式中の全ての符号は前記と同義である。）
この反応に用いる溶剤としては、アセトニトリル及びクロロホルムなどが挙げられる。
式（ｅ２−ａ）で表される化合物は、特開２００６−２５７０７８及び特開２００７−２２４００８号公報に記載されている方法で製造することができる。 <Method for producing salt (E2)>
The production method of the salt (E2) is represented by the formula (e2-1), and -L ^e2 -is -L ^e3 -O-CO- (where L ^e3 is a single bond or 2 having 1 to 15 carbon atoms). An organic sulfonate anion (X _N represents a divalent aliphatic saturated hydrocarbon group, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group). ^The salt (E2) composed of-) will be described as an example. For example, the salt (E2) includes a compound represented by the formula (e2-a) and a compound represented by the formula (e2-b), and a compound represented by the formula (a2-b) in a solvent. It can be produced by using it as a condensing agent and reacting it.

(All symbols in the formula are as defined above.)
Examples of the solvent used in this reaction include acetonitrile and chloroform.
The compound represented by the formula (e2-a) can be produced by the methods described in JP-A-2006-257078 and JP-A-2007-224008.

The compound represented by the formula (e2-b) can be obtained by reacting carbonyldiimidazole or carbonyldiimidazole with a compound represented by the formula (e2-h).

なお、式（ｅ２−ｅ）で表される化合物は、式（ｅ２−ｄ）で表される化合物と、カルボニルジイミダゾールとを反応させることにより得ることができる。

式（ｅ２−ｄ）で表される化合物は、特開２００８−１２７３６７号公報に記載されている方法で製造することができる。 The salt (E2) can also be produced by reacting a compound represented by the formula (e2-e) with a compound represented by the formula (e2-f).

The compound represented by the formula (e2-e) can be obtained by reacting the compound represented by the formula (e2-d) with carbonyldiimidazole.

The compound represented by the formula (e2-d) can be produced by the method described in JP 2008-127367 A.

<Resin (A)>
The resin (A) contained in the resist composition of the present invention is a resin having an acid-decomposable group. Examples of the acid labile group include groups that have already been decomposed by the action of an acid and form a hydrophilic group, as 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) and the acid-decomposable group (2) described in the organic cation (A _a ⁺ ) constituting the salt (B3). The sex 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 resist composition of the present invention 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, the acid stable structural unit represented by any one of formula (a2-1-1), formula (a2-1-2), formula (a2-1-3) and formula (a2-1-4) (A2-1) 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は同一でも異なっていてもよい。
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は同一でも異なっていてもよい。
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は同一でも異なっていてもよい。］ 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, a plurality of R ^a21 may be the same or different.
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, a plurality of R ^a22 may be the same or different.
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. When r1 is 2 or more, a plurality of R ^a23 may be the same or different. ]

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.
<Method for producing resin (A)>

  When the more preferable specific example of resin (A) is illustrated with the combination of a structural unit, resin of the following (A-1)-(A-17) will be mentioned.

  The resin (A) may have a structural unit other than the structural unit, 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、互いに同一でも異なってもよい。］

[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, a plurality of R ^{c4 s} may be the same as 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、互いに同一でも異なってもよい。］

[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 may be the same as 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は互いに同一でも異なってもよい。ｐ３が２以上であるとき、複数のＲ^c15は互いに同一でも異なってもよい。
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, a plurality of R ^{c14 s} may be the same as or different from each other. When p3 is 2 or more, the plurality of R ^c15 may be the same as 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は互いに同一でも異なってもよい。ｒ３が２以上であるとき、複数のＲ^c19は互いに同一でも異なってもよい。ｓ３が２以上であるとき、複数のＲ^c20は互いに同一でも異なってもよい。
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 represents an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 may be the same or different from each other. When r3 is 2 or more, the plurality of R ^c19 may be the same as or different from each other. When s3 is 2 or more, the plurality of R ^c20 may be the same as or different from each other.
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 and 2,2′-dipiconylamine, bipyridine and the like.

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

<Solvent (D)>
The resist composition of the present invention preferably contains a solvent when used in a method for producing a resist pattern described later. 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 the resist composition of this invention containing resin (A), salt (B3), and salt (E2) is demonstrated.
The resist composition of the present invention is, for example, by mixing the resin (A), the salt (B3), the salt (E2) and the solvent (D),
Or
It can be prepared by mixing resin (A), salt (B3), salt (E2), additives such as basic compound (C) and component (F), and 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 (B3) in the resist composition of the present invention is determined based on the content of the resin (A). Specifically, the salt (B3) 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 (E2) in the resist composition of the present invention is determined based on the content of the resin (A). Specifically, the salt (E2) 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). .

  The content of the salt (B3) in the resist composition of the present invention is particularly preferably larger than the content of the salt (E2) in the resist composition of the present invention. When the content ratio of the salt (B3) and the salt (E2) is expressed in the form of [salt (B3)] / [salt (E2)] (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 the resist composition of this invention 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 the basic compound (C), the content ratio is preferably about 0.01 to 6% by mass based on the mass of the solid content of the resist composition of the present invention. About 0.01-4 mass% is further more preferable, and about 0.01-3 mass% is especially 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. 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. The drying is performed by, for example, a heating unit using a heating device such as a hot plate, a decompression unit using a decompression device, or a combination of these units. The conditions of the heating means and the decompression means are adjusted as appropriate. For example, in a heating means using a hot plate (hot plate heating), the surface temperature of the hot plate may be in the range of about 50 to 200 ° C. 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 (B3) and / or salt (E2)) 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 resist pattern manufacturing method including the steps (1) to (5) as described above, the resist composition can manufacture 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（Ｂ３−１−１）で表される化合物４．８５部及びＮ，Ｎ’−ジメチルホルムアミド２８．００部を反応器に仕込み、２３℃で３０分間攪拌した。得られた混合物に、炭酸カリウム１．６６部及びヨウ化カリウム０．８４部を加え、５０℃程度まで昇温した後、同温度で１時間攪拌した。得られた混合物を、４０℃程度まで冷却した後、式（Ｂ３−１−２）で表される化合物６．３０部をＮ，Ｎ’−ジメチルホルムアミド２８．００部に溶解した溶液を１時間かけて滴下し、再び７５℃程度まで昇温し、同温度で５時間攪拌した。得られた反応混合物を、２３℃まで冷却し、クロロホルム６０．００部及び１Ｎ塩酸６０．００部を加えて攪拌・静置した後、有機層と水層とを分液した。回収された有機層をイオン交換水６０．００部で水洗し、この水洗を水層が中性になるまで繰り返した。回収された有機層に活性炭２．０部を加えて攪拌し、ろ過することで活性炭を除去した。得られたろ液を濃縮し、酢酸エチル２０部を加えて攪拌し、上澄液を除去した。続いて、得られた残渣にｔｅｒｔ−ブチルメチルエーテル２０部を加えて攪拌し、上澄液を除去した。得られた残渣をクロロホルムに溶解した後、濃縮し、式（Ｂ３−１−３）で表される化合物を燈色オイル状物として得た。

Synthesis Example 1 (salt (B3); synthesis of B3-1)

4.85 parts of the compound represented by the formula (B3-1-1) and 28.00 parts of N, N′-dimethylformamide were charged into the reactor, and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 1.66 parts of potassium carbonate and 0.84 part of potassium iodide were added, and the temperature was raised to about 50 ° C., followed by stirring at the same temperature for 1 hour. After cooling the obtained mixture to about 40 ° C., a solution prepared by dissolving 6.30 parts of the compound represented by the formula (B3-1-2) in 28.00 parts of N, N′-dimethylformamide was added for 1 hour. The mixture was added dropwise, heated again to about 75 ° C., and stirred at the same temperature for 5 hours. The obtained reaction mixture was cooled to 23 ° C., 60.00 parts of chloroform and 60.00 parts of 1N hydrochloric acid were added and stirred and allowed to stand, and then the organic layer and the aqueous layer were separated. The recovered organic layer was washed with 60.00 parts of ion-exchanged water, and this water washing was repeated until the aqueous layer became neutral. Activated carbon was removed by adding 2.0 parts of activated carbon to the collected organic layer, stirring, and filtering. The obtained filtrate was concentrated, 20 parts of ethyl acetate was added and stirred, and the supernatant was removed. Subsequently, 20 parts of tert-butyl methyl ether was added to the obtained residue and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to give the compound represented by the formula (B3-1-3) as an amber oil.

To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 150 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled to 23 ° C. and neutralized with 88 parts of concentrated hydrochloric acid. The obtained mixture was concentrated to obtain 164.4 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.7%). To 1.9 parts (purity 62.7%) of difluorosulfoacetic acid sodium salt and 9.5 parts of N, N-dimethylformamide, 1.0 part of 1,1′-carbonyldiimidazole was added for 2 hours. Stir to give mixture 1.
On the other hand, 0.2 part of sodium hydride was added to a mixture of 1.1 parts of 3-hydroxyadamantyl methanol and 5.5 parts of N, N-dimethylformamide and stirred for 2 hours. To this solution, mixture 1 was added. The obtained reaction mixture was stirred for 15 hours, and the resulting solution containing the compound represented by the formula (B3-1-4) was directly used in the next reaction.

式（Ｂ３−１−４）で表される化合物１．８１部を含む溶液に、クロロホルム３．２部及び式（Ｂ３−１−３）で表される化合物２．６１部の混合物を添加した。得られた混合物を、１５時間撹拌し、イオン交換水で洗浄した。得られた有機層に、活性炭１．２部を加えて攪拌し、ろ過した。得られたろ液を濃縮し、酢酸エチル１０部を加えて攪拌し、上澄液を除去した。得られた残渣にｔｅｒｔ−ブチルメチルエーテル１０部を加えて攪拌し、上澄液を除去した。得られた残渣をクロロホルムに溶解し、濃縮して燈色オイル状物として、式（Ｂ３−１）で表される塩１．７８部を得た。これを、Ｂ３−１とする。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ４８５．２
ＭＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１

To a solution containing 1.81 parts of the compound represented by the formula (B3-1-4), a mixture of 3.2 parts of chloroform and 2.61 parts of the compound represented by the formula (B3-1-3) was added. . The resulting mixture was stirred for 15 hours and washed with ion exchanged water. To the obtained organic layer, 1.2 parts of activated carbon was added, stirred and filtered. The obtained filtrate was concentrated, 10 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the obtained residue, 10 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to obtain 1.78 parts of a salt represented by the formula (B3-1) as an amber oily substance. This is designated as B3-1.
MS (ESI (+) Spectrum): M ⁺ 485.2
MS (ESI (-) Spectrum): M ^- 339.1

式（Ｂ３−１−４）で表される化合物１．２１部を含む溶液に、クロロホルム４．７９部と式（Ｂ３−２−１）で表される化合物１．５０部の混合物を添加し、１２時間撹拌した。反応混合物をイオン交換水による分液操作により洗浄した後、得られた混合物に活性炭１．０部を加えて攪拌した。ろ過により活性炭を除去し、得られたろ液を濃縮した。残渣に、酢酸エチル１０部を加えて攪拌し、上澄液を除去した。得られた残渣にｔｅｒｔ−ブチルメチルエーテル１０部を加えて攪拌し、上澄液を除去した。得られた残渣をクロロホルムに溶解し、濃縮して、式（Ｂ３−２）で表される塩１．６５部を得た。これを、Ｂ３−２とする。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３９３．１
ＭＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１ Synthesis Example 2 (Salt (B3); Synthesis of B3-2)

To a solution containing 1.21 parts of the compound represented by the formula (B3-1-4), a mixture of 4.79 parts of chloroform and 1.50 parts of the compound represented by the formula (B3-2-1) was added. And stirred for 12 hours. The reaction mixture was washed by a liquid separation operation with ion-exchanged water, and then 1.0 part of activated carbon was added to the obtained mixture and stirred. The activated carbon was removed by filtration, and the obtained filtrate was concentrated. To the residue, 10 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the obtained residue, 10 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to obtain 1.65 parts of the salt represented by the formula (B3-2). This is designated as B3-2.
MS (ESI (+) Spectrum): M ^<+ > 393.1
MS (ESI (-) Spectrum): M ^- 339.1

式（Ｅ２−１−１）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（Ｅ２−１−１）で表される化合物１０．００部及びアセトニトリル６０．００部を反応器に仕込み、４０℃で３０分間攪拌した後、式（ＩＩＩ）で表される化合物（商品名：カルボニルジイミダゾール 東京化成製）４．４４部を添加し、５０℃で１時間攪拌することにより、式（Ｅ２−１−２）で表される化合物を含む溶液を得た。得られた式（Ｅ２−１−２）で表される化合物を含む溶液に、式（Ｅ２−１−３）で表される化合物２．６３部を添加し、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８０部及びイオン交換水３０部を仕込み、攪拌・静置・分液を行った。回収された有機層に再び、イオン交換水３０部を加え、攪拌・静置・分液するという水洗操作を５回繰り返した。水洗後の有機層に活性炭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、得られた濃縮物に、アセトニトリル２５部を添加して溶解し、濃縮した。得られた残渣にｔｅｒｔ−ブチルメチルエーテル３０部を加えて攪拌し、３０分間攪拌し、ろ過することにより、式（Ｅ２−１）で表される化合物４．４８部を得た。この化合物をＥ２−１とする。
ＭＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ２７２．０ Synthesis Example 3 (Salt (E2); Synthesis of E2-1)

The compound represented by the formula (E2-1-1) was synthesized by the method described in JP 2008-127367 A.
After charging 10.00 parts of the compound represented by the formula (E2-1-1) and 60.00 parts of acetonitrile to the reactor and stirring at 40 ° C. for 30 minutes, the compound represented by the formula (III) (trade name) : Carbonyldiimidazole (manufactured by Tokyo Chemical Industry) 4.44 parts was added and stirred at 50 ° C. for 1 hour to obtain a solution containing the compound represented by the formula (E2-1-2). To the obtained solution containing the compound represented by the formula (E2-1-2), 2.63 parts of the compound represented by the formula (E2-1-3) was added and stirred at 23 ° C. for 1 hour. To the obtained reaction mixture, 80 parts of chloroform and 30 parts of ion-exchanged water were added, followed by stirring, standing, and liquid separation. The washing operation of adding 30 parts of ion-exchanged water to the collected organic layer again and stirring, standing, and separating the liquid was repeated 5 times. The organic layer after washing with water was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 25 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To the obtained residue, 30 parts of tert-butyl methyl ether was added, stirred, stirred for 30 minutes, and filtered to obtain 4.48 parts of a compound represented by the formula (E2-1). This compound is designated as E2-1.
MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 272.0

式（Ｅ２−２−１）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（Ｅ２−２−１）で表される化合物６．０３部及びアセトニトリル３０．００部を反応容器に仕込み、２３℃で３０分間攪拌した後、式（ＩＩＩ）で表される化合物（商品名：カルボニルジイミダゾール 東京化成製）１．７０部を添加し、６０℃で１時間攪拌した。得られた反応溶液をろ過した後、回収されたろ液を濃縮した。得られた濃縮物に、クロロホルム３０部及びイオン交換水１５部を加え、２３℃で３０分間攪拌した。その後、静置し、分液して有機層を得た。得られた有機層に、イオン交換水１５部を加え、２３℃で３０分間攪拌した。この水洗の操作をさらに３回行った。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、得られた濃縮物に、ｔｅｒｔ−ブチルメチルエーテル１００部を加えて攪拌した後、ろ過することにより、式（Ｅ２−２）で表される化合物６．１２部を得た。この化合物をＥ２−２とする。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ４３３．１ Synthesis Example 4 (Salt (E2); Synthesis of E2-2)

A compound represented by the formula (E2-2-1) was synthesized by the method described in JP-A-2006-257078.
After charging 6.03 parts of the compound represented by the formula (E2-2-1) and 30.00 parts of acetonitrile into a reaction vessel and stirring at 23 ° C. for 30 minutes, the compound represented by the formula (III) (trade name) : Carbonyldiimidazole (Tokyo Kasei Co., Ltd.) 1.70 parts was added and stirred at 60 ° C. for 1 hour. The obtained reaction solution was filtered, and then the collected filtrate was concentrated. To the obtained concentrate, 30 parts of chloroform and 15 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated and obtained the organic layer. To the obtained organic layer, 15 parts of ion-exchanged water was added and stirred at 23 ° C. for 30 minutes. This washing operation was further performed 3 times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 100 parts of tert-butyl methyl ether was added to the resulting concentrate and stirred, followed by filtration to obtain 6.12 parts of a compound represented by the formula (E2-2). . This compound is designated as E2-2.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 433.1

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 5 [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 6 [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 7 [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 8 [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 12 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.

<Salt>
B3-1: B3-1 obtained in Synthesis Example 1
B3-2: B3-2 obtained in Synthesis Example 2
E2-1: E2-1 obtained in Synthesis Example 3
E2-2: E2-2 obtained in Synthesis Example 4
<Resin (A)>
A1-1: A1-1 obtained in Synthesis Example 5
A1-2: A1-2 obtained in Synthesis Example 6
A1-3: A1-3 obtained in Synthesis Example 7
A1-4: A1-4 obtained in Synthesis Example 8
<Basic compound (C)>
Basic compound C1: 2,6-diisopropylaniline

The solvent (D) used for preparing the resist composition is as follows.
<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 13
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 (B3)

[In the formula (B3),
A _a ⁺ represents an organic cation having an acid-decomposable group and having no nitrogen atom.
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L represents an alkanediyl group having 1 to 5 carbon atoms.
Y represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group may be replaced by an oxygen atom, a sulfonyl group or a carbonyl group,
The hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, An acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or — (CH ₂ ) _j2 —O—CO—R ^b1 (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, and an oil having 3 to 16 carbon atoms Represents a cyclic hydrocarbon group or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4)
It may be substituted with a group represented by ]
A salt (B3) represented by:
Formula (E2)

[In the formula (E2),
A ⁺ represents an organic cation having no nitrogen atom.
X _N ⁻ represents an organic sulfonate anion having a nitrogen atom. ]
The resist composition containing the salt (E2) represented by these. A _a ^{+ in the} formula (B3) is an organic sulfonium cation having an acid-decomposable group and having no nitrogen atom, and A ^{+ in the} formula (E2) is an organic sulfonium cation having no nitrogen atom. The resist composition according to claim 1. The resist composition according to claim 1, wherein A _a ⁺ in the formula (B3) is an organic cation represented by the formula (b3-1).

[In the formula (b3-1),
R ^d1 , R ^d2 and R ^d3 (R ^{d1 to} R ^d3 ) each independently represent a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent not having a nitrogen atom. However, at least one of R ^{d1 to} R ^d3 has the formula (b3-1-1)

(In the formula (b3-1-1),
R ^d4 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.
R ^d5 represents an alkyl group having 1 to 5 carbon atoms.
m3 represents an integer of 0 to 2, and when m3 is 2, two R ^d5 present are the same or different.
^Xb represents a group that is decomposed by the action of an acid.
* Represents a bond with a sulfur atom. )
It is group represented by these.
When one of R ^{d1 to} R ^d3 is a group represented by the formula (b3-1-1), the remaining two may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. ] R ^d1 , R ^d2 and R ^d3 are each independently an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms or a formula ( b3-1-1), a hydrogen atom contained in the alkyl group is substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be 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. The hydrogen atom which may be substituted by the hydrocarbon group and contained in 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 3 to 18 carbon atoms. In claim 3, the alicyclic hydrocarbon group may be substituted. The resist composition as described. The resist composition according to claim 1, wherein X _N ^{− in the} formula (E2) is an organic sulfonate anion represented by the formula (e2-1) or the formula (e2-2).

[In Formula (e2-1) and Formula (e2-2),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
^Le2 represents 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 may be replaced with an oxygen atom or a carbonyl group. Good.
Y ^N is an organic group containing a nitrogen atom. ]   The resist composition according to any one of claims 1 to 5, wherein the content mass of the salt (B) is larger than the content mass of the salt (E2). 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: