JP6174362B2 - Resist composition and method for producing resist pattern - Google Patents

Description

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

また、レジスト組成物から、フォトリソグラフィによりレジストパターンを形成する際、アルカリ現像液で現像するとポジ型レジストパターンが得られ、有機溶剤で現像するとネガ型レジストパターンが得られることが知られている（非特許文献１）。 Patent Document 1 describes a resist composition comprising a resin composed of a structural unit represented by the formula (u-A) and a structural unit represented by the formula (u-C), and triphenylsulfonium triflate. ing.

Further, it is known that when a resist pattern is formed from a resist composition by photolithography, a positive resist pattern is obtained when developed with an alkaline developer, and a negative resist pattern is obtained when developed with an organic solvent ( Non-patent document 1).

JP 2000-122294 A

Published by Techno Times Inc. Monthly Display '11 June p. 31

  An object of the present invention is to provide a resist composition capable of producing a resist pattern having an excellent shape.

［式（Ｉ）中、
Ｒ¹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。
Ａ¹は、単結合、^＊−Ａ²−Ｏ−、^＊−Ａ²−ＣＯ−Ｏ−、^＊−Ａ²−ＣＯ−Ｏ−Ａ³−ＣＯ−Ｏ−又は^＊−Ａ²−Ｏ−ＣＯ−Ａ³−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ａ²及びＡ³は、それぞれ独立に、炭素数１〜６のアルカンジイル基を表す。］

［式（ＩＩ）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。
Ｌ¹は、炭素数１〜１７の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
環Ｗは、炭素数３〜３６の脂環式炭化水素環を表し、該脂環式炭化水素環に含まれる−ＣＨ₂−は、−Ｏ−、−Ｓ−、−ＣＯ−又は−ＳＯ₂−で置き換わっていてもよく、該脂環式炭化水素環に含まれる水素原子は、ヒドロキシ基、炭素数１〜１２の飽和炭化水素基、炭素数１〜１２のアルコキシ基又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。
Ｒ^f1及びＲ^f2は、それぞれ独立に、フッ素原子又は炭素数１〜６のフッ化アルキル基を表す。
ｓは、１〜１０の整数を表し、ｓが２以上のとき、複数のＲ^f1及びＲ^f2はそれぞれ同一又は相異なる。
Ｚ⁺は、有機カチオンを表す。］
［２］環Ｗが、式（ＩＩａ１−１）で表される環、式（ＩＩａ１−２）で表される環又は式（ＩＩａ１−３）で表される環である［１］記載のレジスト組成物。

［式（ＩＩａ１−１）、式（ＩＩａ１−２）及び式（ＩＩａ１−３）中、
環に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基又はスルホニル基で置き換わっていてもよく、環に含まれる水素原子は、ヒドロキシ基、炭素数１〜１２の飽和炭化水素基、炭素数１〜１２のアルコキシ基又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。］
［３］Ｌ¹が、＊−ＣＯ−Ｏ−（ＣＨ₂）_t−（ｔは０〜６の整数を表す。＊は、−Ｃ（Ｑ¹）（Ｑ²）−との結合手を表す。）である請求項１又は２記載のレジスト組成物。
［４］さらに溶剤を含有する［１］〜［３］のいずれか記載のレジスト組成物。
［５］（１）上記［１］〜［４］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）組成物層を露光する工程、
（４）露光後の組成物層を加熱する工程及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A resist composition comprising a resin comprising a structural unit represented by formula (I) and a structural unit having an acid labile group, and an acid generator represented by formula (II).

[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ¹ is a single bond, ^* —A ² —O—, ^* —A ² —CO—O—, ^* —A ² —CO—O—A ³ —CO—O—, or ^* —A ² —O—CO. -A ³ represents a -O-.
* Represents a bond with -O-.
A ² and A ³ each independently represents an alkanediyl group having 1 to 6 carbon atoms. ]

[In the formula (II),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms, and —CH ₂ — contained in the alicyclic hydrocarbon ring is —O—, —S—, —CO— or —SO _2. -The hydrogen atom contained in the alicyclic hydrocarbon ring may be a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or 6 to 10 carbon atoms. The aromatic hydrocarbon group may be substituted.
R ^f1 and R ^f2 each independently represent a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
s represents an integer of 1 to 10, and when s is 2 or more, a plurality of R ^f1 and R ^f2 are the same or different.
Z ⁺ represents an organic cation. ]
[2] The resist according to [1], wherein ring W is a ring represented by formula (IIa1-1), a ring represented by formula (IIa1-2), or a ring represented by formula (IIa1-3) Composition.

[In Formula (IIa1-1), Formula (IIa1-2) and Formula (IIa1-3),
The methylene group contained in the ring may be replaced by an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or a carbon number. It may be substituted with an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ]
[3] L ¹ represents * —CO—O— (CH ₂ ) _t — (t represents an integer of 0 to 6. * represents a bond to —C (Q ¹ ) (Q ² ) —. 3) The resist composition according to claim 1 or 2.
[4] The resist composition according to any one of [1] to [3], further containing a solvent.
[5] (1) The process of apply | coating the resist composition in any one of said [1]-[4] on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  According to the resist composition of the present invention, a resist pattern having an excellent shape can be produced.

It is a schematic sectional drawing for demonstrating the shape of the resist pattern manufactured from the resist composition of this invention.

The term "(meth) acrylic monomer" as used herein means at least one monomer having a structure of "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " . 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.

<Resist composition>
The resist composition of the present invention comprises:
A resin comprising a structural unit represented by formula (I) and a structural unit having an acid labile group (hereinafter sometimes referred to as “resin (A)”), and an acid generator represented by formula (II) (hereinafter referred to as “resin (A)”) (Sometimes referred to as “acid generator (II)”).
It is preferable that the resist composition of the present invention further contains a solvent (E).

<Resin (A)>
The resin (A) has a structural unit represented by the formula (I) and a structural unit having an acid labile group. The resin (A) may further have a structural unit having no acid labile group.
In the present specification, the “acid labile group” is a group having a leaving group and forming a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group by contact with an acid. Means.

［式（Ｉ）中、
Ｒ¹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。
Ａ¹は、単結合、^＊−Ａ²−Ｏ−、^＊−Ａ²−ＣＯ−Ｏ−、^＊−Ａ²−ＣＯ−Ｏ−Ａ³−ＣＯ−Ｏ−又は^＊−Ａ²−Ｏ−ＣＯ−Ａ³−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ａ²及びＡ³は、それぞれ独立に、炭素数１〜６のアルカンジイル基を表す。］ <Structural unit represented by formula (I)>
The resin (A) has a structural unit represented by the formula (I) (hereinafter sometimes referred to as “structural unit (I)”).

[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ¹ is a single bond, ^* —A ² —O—, ^* —A ² —CO—O—, ^* —A ² —CO—O—A ³ —CO—O—, or ^* —A ² —O—CO. -A ³ represents a -O-.
* Represents a bond with -O-.
A ² and A ³ each independently represents an alkanediyl group having 1 to 6 carbon atoms. ]

Examples of the halogen atom for R ¹ in formula (I) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkyl group for R ¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. , Preferably it is a C1-C4 alkyl group, More preferably, it is a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom for R ¹ include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluoro group. Examples include a hexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.
R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom, a methyl group or an ethyl group.

Examples of the alkanediyl group of A ² and A ³ include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Diyl group and hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples include 4-diyl group and 2-methylbutane-1,4-diyl group.
A ¹ is preferably a single bond or ^* —A ² —CO—O—, more preferably a single bond, —CH ₂ —CO—O— or —C ₂ H ₄ —CO—O—. .

Specific examples of the structural unit (I) are shown below.

Regarding the structural units represented by formula (aa-1) to formula (aa-6), structural units in which the methyl group corresponding to R ¹ is replaced with a hydrogen atom are also exemplified as specific examples of structural unit (I). Can do.

［式（Ｉ’）中、Ｒ¹及びＡ¹は上記と同じ意味を表す。］ The structural unit (I) is derived from a compound represented by the formula (I ′) (hereinafter sometimes referred to as “compound (I ′)”).

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

［式中、Ｒ¹は上記と同じ意味を表す。］ The compound represented by the formula (I′-1), wherein A ¹ in the compound (I ′) is * —CH ₂ —CO—O— (* represents a bond to —CO—O—), The compound represented by formula (I′-1-a) can be obtained by reacting the compound represented by formula (I′-1-b) in a solvent. Here, methylene chloride, tetrahydrofuran, acetonitrile, and the like are preferably used as the solvent.

[Wherein R ¹ represents the same meaning as described above. ]

［式中、Ｒ¹は上記と同じ意味を表す。］
この反応においては、ジシクロヘキシルカルボジイミドなどの縮合触媒を用いることもできる。 The compound represented by the formula (I′-1-a) is obtained by reacting the compound represented by the formula (I′-1-c) with the compound represented by the formula (I′-1-d). Can be obtained. This reaction is preferably carried out in the presence of a solvent such as methylene chloride, tetrahydrofuran and acetonitrile.

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

式（Ｉ’−１−ｃ）で表される化合物として、目的の化合物（Ｉ’）に対応したＡ¹及びＲ¹を有する化合物を用いれば、目的の化合物（Ｉ’）を得ることができる。式（Ｉ’−１−ｃ）及び式（Ｉ’−１−ｄ）で表される化合物は、市場から容易に入手できる。 Examples of the compound represented by the formula (I′-1-c) include the following compounds.

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

Examples of compound (I ′) include the following.

Regarding the compound (I ′) represented by each of the formulas (aa′-1) to (aa′-6), the structural unit in which the methyl group corresponding to R ¹ is replaced with a hydrogen atom is also represented by the compound (I ′). Specific examples can be given.

  The content of the structural unit (I) is preferably 1 to 80 mol%, more preferably 2 to 75 mol%, still more preferably 3 to 70 mol% with respect to all the structural units of the resin (A). %, Particularly preferably 5 to 65 mol%.

<Structural unit having acid labile group>
A structural unit having an acid labile group (hereinafter sometimes referred to as “acid labile structural unit”) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “acid labile monomer (a1)”). .
Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

［式（１）中、Ｒ^a1、Ｒ^a2及びＲ^a3は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組み合わせた基を表すか、Ｒ^a1及びＲ^a2は互いに結合して炭素数２〜２０の２価の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し、該炭化水素基及び該２価の炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−又は−Ｓ−で置き換わってもよい。］

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

[In Formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group. May be replaced by -O- or -S-. ]

アルキル基で置換された脂環式炭化水素基としては、例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基等が挙げられる。
式（１）においては、Ｒ^a1、Ｒ^a2及びＲ^a3で表される脂環式炭化水素基は、好ましくは炭素数３〜１６である。 ^Examples of the alkyl group represented by R ^a1 , R ^a2 and 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 represented by R ^a1 , R ^a2 and R ^a3 may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group is an alkyl group. May be substituted. In this case, the carbon number of the alicyclic hydrocarbon group is 20 or less including the carbon number of the alkyl group.
Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond).

Examples of the alicyclic hydrocarbon group substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
In the formula (1), the alicyclic hydrocarbon group represented by R ^a1 , R ^a2 and R ^a3 preferably has 3 to 16 carbon atoms.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group include the following groups. The divalent hydrocarbon group preferably has 3 to 12 carbon atoms. In each formula, R ^a3 has the same meaning as described above, and * represents a bond to —O—.

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

Examples of the hydrocarbon group for R ^{a1 ′} , R ^{a2 ′} and R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining these.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include a divalent aliphatic hydrocarbon group.

In Formula (2), it is preferable that at least one of R ^{a1 ′} and R ^{a2 ′} is a hydrogen atom.
Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

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

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

  As a structural unit derived from a (meth) acrylic monomer having a group represented by formula (1), preferably a structural unit represented by formula (a1-1) or a structure represented by formula (a1-2) Units are listed. These may be contained independently and 2 or more types may be contained. In this specification, the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) are represented by the structural unit (a1-1) and the structural unit (a1-2), respectively. The monomer that derives the structural unit (a1-1) and the monomer that derives the structural unit (a1-2) may be referred to as a monomer (a1-1) and a monomer (a1-2), respectively.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜１８の脂環式炭化水素基を表す。
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。］

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

L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, more preferably —O—. k1 is preferably an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an alkyl group. . In this case, the carbon number of the alicyclic hydrocarbon group is 10 or less including the carbon number of the alkyl group. Specific examples include the same groups as those represented by R ^a1 , R ^a2 and R ^a3 in formula (1).
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

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

Examples of the monomer (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethylcycloheptan-1-yl (meth). Examples include acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, and 1-isopropylcyclopentan-1-yl (meth) acrylate. Monomers represented by the formula (a1-2-1) to the formula (a1-2-12) are preferred, and the formula (a1-2-3) to the formula (a1-2-4) or the formula (a1-2-9) The monomer represented by formula (a1-2-10) is more preferable, and the monomer represented by formula (a1-2-3) or formula (a1-2-9) is more preferable.

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

式（ａ１−５）中、
Ｒ³¹は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｚ^a1は、単結合又は＊−［ＣＨ₂］_k4−ＣＯ−Ｌ^a34−基を表す。ここで、ｋ４は１〜４の整数を表す。＊は、Ｌ^a31との結合手を表す。
Ｌ^a31、Ｌ^a32、Ｌ^a33及びＬ^a34は、それぞれ独立に、−Ｏ−又は−Ｓ−を表す。
ｓ１は、１〜３の整数を表す。
ｓ１’は、０〜３の整数を表す。 As another acid labile monomer (a1), for example, a monomer represented by formula (a1-5) which is a (meth) acrylic monomer having an acid labile group (hereinafter referred to as “monomer (a1-5)”) May be used).

In formula (a1-5),
R ³¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or a * — [CH ₂ ] _k4 —CO—L ^a34 — group. Here, k4 represents an integer of 1 to 4. * Represents a bond with L ^a31 .
L ^a31 , L ^a32 , L ^a33 and L ^a34 each independently represent —O— or —S—.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3.

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ^a31 is preferably an oxygen atom.
One of L ^a32 and L ^a33 is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

Examples of the monomer (a1-5) include the following monomers.

  When the resin (A) has a structural unit derived from the monomer (a1-5), the content is preferably from 1 to 50 mol%, preferably from 3 to 45 mol, based on all structural units of the resin (A). % Is more preferable, and 5 to 40 mol% is more preferable.

<Structural unit without acid labile group>
The structural unit having no acid labile group (hereinafter sometimes referred to as “acid stable structural unit”) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “acid stable monomer”).
As an acid stable monomer, Preferably, the monomer which has a hydroxyl group or a lactone ring is mentioned. Acid-stable monomer having a hydroxy group (hereinafter sometimes referred to as “acid-stable monomer having a hydroxy group (a2)”) or acid-stable monomer having a lactone ring (hereinafter referred to as “acid-stable monomer having a lactone ring (a3)”) If a resin having a structural unit derived from (sometimes) is used, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Acid-stable monomer having a hydroxy group (a2)>
When the resist composition is used for high energy beam exposure such as KrF excimer laser exposure (248 nm), electron beam or EUV (ultra-ultraviolet light), the acid-stable monomer (a2) having a hydroxy group is preferably a hydroxystyrene. An acid stable monomer having a certain phenolic hydroxy group is used. When using short-wavelength ArF excimer laser exposure (193 nm) or the like, the acid-stable monomer (a2) having a hydroxy group is preferably an acid-stable monomer having a hydroxyadamantyl group represented by the formula (a2-1). use. The acid-stable monomer (a2) having a hydroxy group may be used alone or in combination of two or more.

式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を表し、
ｋ２は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 Examples of the acid stable monomer having a hydroxyadamantyl group include a monomer represented by the formula (a2-1).

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

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

Examples of the acid stable monomer represented by the formula (a2-1) include monomers described in JP2010-204646A. A monomer represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable, and represented by any one of formula (a2-1-1) to formula (a2-1-4). The monomer represented by Formula (a2-1-1) or Formula (a2-1-3) is more preferable.

  When the resin (A) contains a structural unit derived from the acid-stable monomer (a2), the content thereof is usually 1 to 45 mol%, preferably 1 to 45 mol% with respect to all the structural units of the resin (A). It is 40 mol%, More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

<Acid-stable monomer having a lactone ring (a3)>
The lactone ring possessed by the acid stable monomer (a3) may be, for example, a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and a monocyclic lactone ring and other rings The condensed ring may be used. Among these lactone rings, a γ-butyrolactone ring or a condensed ring of γ-butyrolactone ring and another ring is preferable.

  The acid-stable monomer (a3) having a lactone ring is preferably represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3). These 1 type may be used independently and may use 2 or more types together.

式（ａ３−１）、式（ａ３−２）及び式（ａ３−３）中、
Ｌ^a4、Ｌ^a5及びＬ^a6は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−を表す。
ｋ３は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a18、Ｒ^a19及びＲ^a20は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a21は、炭素数１〜４のアルキル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a22及びＲ^a23は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１〜４のアルキル基を表す。
ｑ１及びｒ１は、それぞれ独立に０〜３の整数を表す。ｐ１が２以上のとき、複数のＲ^a21は同一又は相異なり、ｑ１が２以上のとき、複数のＲ^a22は同一又は相異なり、ｒ１が２以上のとき、複数のＲ^a23は、同一又は相異なる。

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

^Examples of the alkyl group for R ^a21 , R ^a22 and R ^a23 include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, and a sec-butyl group.

In formula (a3-1), formula (a3-2) and formula (a3-3), L ^a4 , L ^a5 and L ^a6 are each independently —O— or ^* —O— (CH ₂ ) _k3 —. CO-O- is preferable, and -O- is more preferable. k3 is preferably an integer of 1 to 4, more preferably 1.
R ^a18 , R ^a19 , R ^a20 and R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably 0 to 2, more preferably 0 or 1.

  Examples of the acid stable monomer (a3) include monomers described in JP 2010-204646 A. Formula (a3-1-1) to Formula (a3-1-4), Formula (a3-2-1) to Formula (a3-2-4), and Formula (a3-3-1) to Formula (a3-3) -4) is preferred, and the monomer represented by formula (a3-1-1), formula (a3-1-2), formula (a3-2-3), and formula (a3-2-4) is preferred. The monomer represented by any of these is more preferable, and the monomer represented by Formula (a3-1-1) or Formula (a3-2-3) is more preferable.

  When the resin (A) includes a structural unit derived from the acid-stable monomer (a3) having a lactone ring, the content is usually 5 to 70 mol% with respect to all the structural units of the resin (A), Preferably it is 10-65 mol%, More preferably, it is 10-60 mol%.

When the resin (A) is a resin composed only of the structural unit (I) and the acid labile structural unit, these contents are respectively relative to the total structural unit of the resin (A),
Structural unit (I); 1 to 80 mol%
Acid-labile structural unit; 20-99 mol%
Is preferred,
Structural unit (I); 5-65 mol%
Acid labile structural unit; 35-95 mol%
Is more preferable.

When the resin (A) is a resin composed of the structural unit (I), the acid labile structural unit, and the acid stable structural unit, these content rates are respectively based on the total structural units of the resin (A),
Structural unit (I); 1 to 80 mol%
Acid-labile structural unit; 17-96 mol%
Acid stable structural unit; 3-82 mol%
Is preferred,
Structural unit (I); 2-75 mol%
Acid-labile structural unit; 20 to 93 mol%
Acid stable structural unit; 5-78 mol%
Is more preferred,
Structural unit (I); 5-65 mol%
Acid-labile structural unit; 30 to 90 mol%
Acid stable structural unit; 5 to 65 mol%
Is more preferable.

  Resin (A) is a structural unit derived from a monomer having an adamantyl group (particularly a structural unit represented by formula (a1-1)), preferably a total of structural units derived from an acid labile monomer (a1). It is preferable to contain 15 mol% or more with respect to the quantity. When the ratio of the structural unit having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

The resin (A) is preferably a resin comprising a structural unit (I), an acid labile structural unit, and an acid stable structural unit, that is, the compound (I ′), the acid labile monomer (a1), and an acid stable It is a copolymer with a monomer.
In this copolymer, the acid labile structural unit is preferably at least one of the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), more preferably. Is a structural unit (a1-1).
The acid stable structural unit is preferably at least one of a structural unit derived from the acid stable monomer (a2) and a structural unit derived from the acid stable monomer (a3). The acid stable monomer (a2) is preferably a monomer represented by the formula (a2-1). The acid stable monomer (a3) is preferably at least one of an acid stable monomer represented by the formula (a3-1) and an acid stable monomer represented by the formula (a3-2).

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do.
The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, and further preferably 15,000 or less).

<Resin other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A). Examples of such a resin include a resin comprising a structural unit derived from an acid labile monomer (a1), a structural unit derived from an acid stable monomer, or a structural unit derived from a known monomer used in the field. Can be mentioned.
When the resist composition of this invention contains resin other than resin (A), these content rates are 0.1-50 mass% normally with respect to the total amount of resin, Preferably 0.5-30 It is mass%, More preferably, it is 1-20 mass%.

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

［式（ＩＩ）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。
Ｌ¹は、２価の炭素数１〜１７の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
環Ｗは、炭素数３〜３６の脂環式炭化水素環を表し、該脂環式炭化水素環に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基又はスルホニル基で置き換わっていてもよく、該脂環式炭化水素環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、炭素数３〜１２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で置換されていてもよい。
Ｒ^f1及びＲ^f2は、それぞれ独立に、フッ素原子又は炭素数１〜６のフッ化アルキル基を表す。
ｓは、１〜１０の整数を表し、ｓが２以上の場合、複数のＲ^f1及びＲ^f2はそれぞれ同一又は相異なる。
Ｚ⁺は、有機カチオンを表す。］
本明細書では、式（ＩＩ）において、正電荷を有するＺ⁺で示される有機カチオンを除去してなる負電荷を有するものを「スルホン酸アニオン」ということがある。 <Acid generator (II)>
The acid generator (II) is an acid generator containing a salt represented by the formula (II).

[In the formula (II),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon ring may be replaced with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the alicyclic hydrocarbon ring is a hydroxy group, 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 12 carbon atoms, or carbon. The aromatic hydrocarbon group of several 6-10 may be substituted.
R ^f1 and R ^f2 each independently represent a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
s represents an integer of 1 to 10, and when s is 2 or more, a plurality of R ^f1 and R ^f2 are the same or different.
Z ⁺ represents an organic cation. ]
In the present specification, a compound having a negative charge obtained by removing an organic cation represented by Z ⁺ having a positive charge in formula (II) may be referred to as a “sulfonate anion”.

Examples of the C 1-6 perfluoroalkyl group represented by Q ¹ and Q ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, A perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group and the like can be mentioned.
Q ¹ and Q ² are preferably each independently a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ¹ include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these A combination of two or more of the groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group); For example, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4 A branched alkanediyl group such as a diyl group or 2-methylbutane-1,4-diyl group;
Cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,2-diyl group, 1-methylcyclohexane-1,2-diyl group, cyclohexane-1,4-diyl group, cyclo A monocyclic divalent alicyclic saturated hydrocarbon group which is a cycloalkanediyl group such as an octane-1,2-diyl group or a cyclooctane-1,5-diyl group;
A polycyclic group such as norbornane-2,3-diyl group, norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. A bivalent alicyclic saturated hydrocarbon group etc. are mentioned.
The divalent alicyclic hydrocarbon group may be a group obtained by removing any one hydrogen atom from a monovalent alicyclic hydrocarbon group described later.

Examples of the group in which the methylene group in the divalent saturated hydrocarbon group of L ¹ is replaced by an oxygen atom or a carbonyl group are represented by any of the following formulas (b1-1) to (b1-7). Groups. The formula (b1-1) to the formula (b1-7) are described in accordance with the formula (II) on the left and right. Of the two bonds represented by *, the left bond is C ( Q ¹ ) is bonded to the carbon atom of (Q ² ). The same applies to specific examples of the following formulas (b1-1) to (b1-7).

式（ｂ１−１）〜式（ｂ１−７）中、
Ｌ^b2は、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の２価の飽和炭化水素基を表す。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２価の飽和炭化水素基を表す。
Ｌ^b6は、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b7は、炭素数１〜１５の２価の飽和炭化水素基を表す。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２価の飽和炭化水素基を表す。
Ｌ^b9は、単結合又は炭素数１〜１１の２価の飽和炭化水素基を表す。Ｌ^b10は、炭素数１〜１２の２価の飽和炭化水素基を表す。但しＬ^b9及びＬ^b10の合計炭素数の上限は１２である。
Ｌ^b11及びＬ^b12は、それぞれ独立に、単結合又は炭素数１〜１４の飽和炭化水素基を表す。但しＬ^b11及びＬ^b12の合計炭素数の上限は１４である。

In formula (b1-1) to formula (b1-7),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b7 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 represents a single bond or a divalent saturated hydrocarbon group having 1 to 11 carbon atoms. L ^b10 represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.
L ^b11 and L ^b12 each independently represent a single bond or a saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b11 and L ^b12 is 14.

L ¹ is preferably a group represented by any one of formulas (b1-1) to (b1-5), more preferably any one of formulas (b1-1) to (b1-4). A group represented by formula (b1-1) or formula (b1-3), particularly preferably a divalent group represented by formula (b1-1). is there. Among them, preferably, L ^b2 in formula (b1-1) is a single bond or a saturated hydrocarbon group having 1 to 6 carbon atoms, and more preferably * —CO—O— (CH ₂ ) _t — (t is Represents an integer of 0 to 6. * represents a bond to —C (Q ¹ ) (Q ² ) —, and more preferably, L ^b2 is a single bond or a methylene group (b1- A divalent group represented by 1), particularly preferably a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond, that is, * —CO—O—.

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.

Examples of the divalent group represented by the formula (b1-7) include the following.

なかでも、環Ｗは、式（ＩＩａ１−１）で表される環、式（ＩＩａ１−２）で表される環又は式（ＩＩａ１−３）で表される環が好ましい。

［式（ＩＩａ１−１）、式（ＩＩａ１−２）及び式（ＩＩａ１−３）中、
環に含まれるメチレン基は酸素原子、硫黄原子、カルボニル基又はスルホニル基で置換されていてもよく、環に含まれる水素原子は、ヒドロキシ基、炭素数１〜１２の飽和炭化水素基、炭素数１〜１２のアルコキシ基又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。］ The alicyclic hydrocarbon ring having 3 to 36 carbon atoms in the ring W may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon ring include cyclopentane and cyclohexene. Examples include cycloalkane rings such as xane, methylcyclohexane, dimethylcyclohexane, cycloheptane, and cyclooctane ring. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthalene, adamantane, norbornane, methylnorbornane ring, and the following rings.

Among these, the ring W is preferably a ring represented by the formula (IIa1-1), a ring represented by the formula (IIa1-2), or a ring represented by the formula (IIa1-3).

[In Formula (IIa1-1), Formula (IIa1-2) and Formula (IIa1-3),
The methylene group contained in the ring may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or a carbon number. It may be substituted with an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ]

Saturated hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and other alkyl groups; cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Cycloalkyl groups such as: a group in which an alkyl group such as a methylcyclohexyl group or a dimethylcyclohexyl group and a cycloalkyl group are combined.
Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentyloxy group, and an n-hexyloxy group. Can be mentioned.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. , Aryl groups such as biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.

In the ring W described above, the position of the bond between L ¹ and two oxygen atoms can be any position. Among them, in the ring represented by the formula (IIa1-1), the ring represented by the formula (IIa1-2) or the ring represented by the formula (IIa1-3), the bond * is the following position. Those are preferred.

Examples of the fluorinated alkyl group for R ^f1 and R ^f2 include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, and a 2,2,2-trifluoroethyl group. Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1, 2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2 , 2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoro Propyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5- Decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2, 2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentyl A methyl group and a perfluorohexyl group are mentioned. Of these, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, and the like are preferable.
R ^f1 and R ^f2 are preferably fluorine atoms.

が、以下の基であるものが特に好ましい。

s is preferably an integer of 1 to 8, more preferably an integer of 1 to 6, more preferably an integer of 1 to 4, and a ring containing 1 or 2, that is, —O—C—O—.

However, those having the following groups are particularly preferred.

Specific examples of the sulfonate anion of formula (II) include the following.

Examples of the organic cation represented by Z ⁺ include an organic onium cation such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an arylsulfonium cation is more preferable.

More preferably, for example, cations represented by the formulas (Z1) to (Z4) may be used.

In formula (Z1) to formula (Z4),
Do P ^{a to} P ^c each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms? , P ^a and P ^b may be combined to form a ring containing a sulfur atom. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or It may be substituted with an alkoxy group having 1 to 12 carbon atoms.

P ⁴ and P ⁵ each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
P ⁶ and P ⁷ each independently represent an aliphatic hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or P ⁶ and P ^{7 taken} together Forms a ring containing a sulfur atom to which.
P ⁸ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
P ⁹ represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group has 1 to 12 carbon atoms. Or an alkoxycarbonyloxy group having 1 to 12 carbon atoms.
P ⁸ and P ⁹ may combine to form a ring containing —CH—CO— to which they are attached.

P ¹⁰ to P ¹⁵ each independently represent a hydroxy group, an aliphatic hydrocarbon group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms.
E represents -S- or -O-.
i, j, p, r, x and y each independently represents an integer of 0 to 5;
q represents 0 or 1;
v and w each independently represent an integer of 0 to 4.
When i is 2 or more, the plurality of P ⁴ are the same or different from each other. When j is 2 or more, the plurality of P ⁵ are the same or different from each other. When p is 2 or more, the plurality of P ¹⁰ are the same. Or, when r is 2 or more, a plurality of P ¹¹ are the same or different from each other, when v is 2 or more, a plurality of P ¹² are the same or different from each other, and when w is 2 or more, a plurality of P 11 ¹³ are the same or different from each other, when x is 2 or more, a plurality of P ¹⁴ are the same or different from each other, when y is 2 or more, a plurality of P ¹⁵ are the same or different from each other.

特に、Ｐ⁶〜Ｐ⁸の脂環式炭化水素基は、好ましくは炭素数３〜３６であり、より好ましくは炭素数３〜１８、さらに好ましくは炭素数４〜１２である。 Examples of the aliphatic hydrocarbon group 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-ethylhexyl group. Is mentioned. In particular, aliphatic hydrocarbon group of P ⁶ to P ⁸ is preferably 1 to 12 carbon atoms.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include an aralkyl group, and specifically include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Groups and the like.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. And cycloalkyl groups such as cycloheptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups.

In particular, the alicyclic hydrocarbon group of P ^{6 to} P ⁸ preferably has 3 to 36 carbon atoms, more preferably 3 to 18 carbon atoms, and still more preferably 4 to 12 carbon atoms.

Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a 2-alkyladamantan-2-yl group, and a methyl group. A norbornyl group, an isobornyl group, etc. are mentioned.
As an aromatic hydrocarbon group, phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group, p-methoxyphenyl group And aryl groups such as p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenylyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
When the aromatic hydrocarbon group includes an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, the aliphatic hydrocarbon group having 1 to 18 carbon atoms and the alicyclic hydrocarbon having 3 to 18 carbon atoms Groups are preferred.

As the alkoxy group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, n-hexyloxy group, heptyloxy group Octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group and the like.
As an aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group, 4-methoxyphenyl group etc. are mentioned, for example.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

  Examples of the alkyl group in which a hydrogen atom is substituted with an aromatic hydrocarbon group, that is, an aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.

The ring formed by combining P ^a and P ^b may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings, and a sulfur atom In addition, one or more sulfur atoms and / or one or more oxygen atoms, that is, —O—, —S—, or —CO— may be further included. This ring includes a 3-membered ring to a 18-membered ring, preferably a 3-membered ring to a 12-membered ring or a 4- to 18-membered ring.
The ring formed by combining P ⁶ and P ⁷ may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings, If it contains one or more, it may further contain one or more sulfur atoms and / or one or more oxygen atoms, that is, —O—, —S—, or —CO—. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring.
The ring formed by combining P ⁸ and P ⁹ may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings, and —CH— As long as it contains CO-, it may further contain one or more sulfur atoms and / or one or more oxygen atoms, that is, -O-, -S-, -CO-. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring.

Examples of the ring formed with the sulfur atom to which P ⁶ and P ⁷ are bonded 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 with —CH—CO— to which P ⁸ and P ⁹ are bonded include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the cations represented by the formulas (Z1) to (Z4), the formula (Z1) is preferable, the cation represented by the formula (Z5) is more preferable, and the triphenylsulfonium cation (in the formula (Z5), z1 = z2 = z3 = 0), in diphenyl tolyl sulfonium cation (formula (Z5), a z1 = z2 = 0, z3 = 1, P 3 is a methyl group.) or tri tolyl sulfonium cation (formula (Z5) in Z1 = z2 = z3 = 1, and P ¹ , P ² and P ³ are all methyl groups.

式（Ｚ５）中、
Ｐ¹〜Ｐ³は、それぞれ独立に、ハロゲン原子、ヒドロキシ基、炭素数１〜１８の脂肪族炭化水素基、炭素数３〜１８の脂環式炭化水素基又は炭素数１〜１２のアルコキシ基を表すか、Ｐ¹〜Ｐ³から選ばれる２つが一緒になって硫黄原子を含む環を形成してもよい。
ｚ１、ｚ２及びｚ３は、それぞれ独立に、０〜５の整数を表す。ｚ１が２以上のとき、複数のＰ¹は、互いに同一又は相異なり、ｚ２が２以上のとき、複数のＰ²は、互いに同一又は相異なり、ｚ３が２以上のとき、複数のＰ³は、互いに同一又は相異なる。

In formula (Z5),
P ^{1 to} P ³ are each independently a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. Or two selected from P ^{1 to} P ³ may be combined to form a ring containing a sulfur atom.
z1, z2 and z3 each independently represents an integer of 0 to 5. When z1 is 2 or more, a plurality of P ¹ are the same or different from each other, when z2 is 2 or more, P ² are the same or different from each other, when z3 is 2 or more, a plurality of P ³ is Are the same or different from each other.

The ring formed by combining two selected from P ^{1 to} P ³ may be any of monocyclic, polycyclic, aromatic and non-aromatic rings. As long as it contains the above, it may contain one or more sulfur atoms and / or one or more oxygen atoms.
The P ^{1 to} P ³ aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
Among these, P ^{1 to} P ³ each independently represent 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, or P ¹ two selected from to P ³ is represent together -O-, it is preferable to form a ring containing a sulfur atom. z1 to z3 are preferably each independently 0 or 1.

Examples of the cation represented by the formula (Z1) or the formula (Z5) include the following.

The following are mentioned as a specific example of the cation in which the ring containing a sulfur atom was formed among the cations represented by a formula (Z5).

Specific examples of the cation represented by the formula (Z1) include the following.

Specific examples of the cation represented by the formula (Z2) include the following.

Specific examples of the cation represented by the formula (Z3) include the following.

Specific examples of the cation represented by the formula (Z4) include the following.

  The acid generator (II) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned sulfonate anion and cation can be arbitrarily combined. In the following formulae, the definition of the substituent has the same meaning as described above.

Examples of the acid generator represented by the formula (II) include the following compounds.

（式中、Ｑ¹、Ｑ²、Ｗ、Ｒ^f1、Ｒ^f2、ｓ及びＺ⁺は、それぞれ上記と同義である。） Of the acid generator (II), a method for producing a compound represented by the formula (b1) is shown below.

(In the formula, Q ¹ , Q ² , W, R ^f1 , R ^f2 , s and Z ⁺ are as defined above.)

First, a salt represented by the formula (b1) is prepared by reacting a salt represented by the formula (b1-a) with a compound represented by the formula (b1-b) in a solvent under an acid catalyst condition. Get. Examples of the solvent include 1,2-dichloroethane. Examples of the catalyst include p-toluenesulfonic acid.

The salt represented by the formula (b1-a) can be synthesized, for example, by the method described in JP2007-224008A.
Examples of the compound represented by the formula (b1-b) include 2,2,3,3-tetrafluoro-1,4-butanediol.

  The salt represented by the formula (II) may be used alone or in combination of two or more.

<Acid generator (B)>
The resist composition of the present invention may contain an acid generator other than the salt represented by the formula (II) described above (hereinafter sometimes referred to as “acid generator (B)”). A known acid generator can be used as the acid generator (B).
The acid generator (B) is classified into a nonionic type and an ionic type, and any of them may be used in the resist composition of the present invention.
Examples of the nonionic acid generator include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonates), sulfones (e.g. disulfone, ketosulfone, sulfonyldiazomethane) and the like. The ionic acid generator is typically an onium salt containing an onium cation (for example, diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, and JP-A 63-163452. No. 62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. It is possible to use a compound that generates an acid by radiation.

［式（Ｂ１）中、
Ｑ^b1及びＱ^b2は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１〜２４の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置き換わっていてもよく、該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は、水素原子、フッ素原子、置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該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い。
Ｚ１⁺は、有機カチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a sulfonate represented by the formula (B1).

[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, and methylene constituting the saturated hydrocarbon group The group may be replaced by an oxygen atom or a carbonyl group.
Y represents a hydrogen atom, a fluorine atom, or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A sulfonyl group or a carbonyl group may be substituted.
Z1 ⁺ represents an organic cation. ]

^Examples of the perfluoroalkyl group of Q ^b1 and Q ^b2 include the same as the perfluoroalkyl group of Q ¹ and Q ² in the above formula (II).
Q ^b1 and Q ^b2 are preferably a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group represented by L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, A combination of two or more of the groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group); For example, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4 A branched alkanediyl group such as a diyl group or 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the saturated hydrocarbon group represented by L ^{b1 in} which the methylene group is replaced with an oxygen atom or a carbonyl group include formula (b1-1 ′) to formula (b1-7 ′). In addition, Formula (b1-1 ')-Formula (b1-6') have described the right and left according to Formula (B1), and it is C on the left side among two bonds represented by *, respectively. It binds to (Q ^b1 ) (Q ^b2 ) — and on the right side to —Y. The same applies to specific examples of the following formulas (b1-1 ′) to (b1-7 ′).

式（ｂ１−１’）〜式（ｂ１−６’）中、
Ｌ^b2'は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表す。
Ｌ^b3’は、単結合又は炭素数１〜１９の２価の飽和炭化水素基を表す。
Ｌ^b4’は、炭素数１〜２０の２価の飽和炭化水素基を表す。但しＬ^b3’及びＬ^b4’の炭素数上限は２０である。
Ｌ^b5’は、炭素数１〜２２の２価の飽和炭化水素基を表す。
Ｌ^b6’及びＬ^b7’は、それぞれ独立に、炭素数１〜２２の２価の飽和炭化水素基を表す。但しＬ^b6’及びＬ^b7’の炭素数上限は２３である。
Ｌ^b8’は、炭素数１〜２２の２価の飽和炭化水素基を表す。
Ｌ^b9’及びＬ^b10’は、それぞれ独立に、炭素数１〜１８の２価の飽和炭化水素基を表す。但しＬ^b9’及びＬ^b10’の炭素数上限は２０である。
Ｌ^b11’は、単結合又は炭素数１〜２０の２価の脂肪族飽和炭化水素基を表す。
Ｌ^b12’は、炭素数１〜２１の２価の脂肪族飽和炭化水素基を表す。但しＬ^b11’及びＬ^b12’の合計炭素数の上限は２１である。

In formula (b1-1 ′) to formula (b1-6 ′),
L ^{b2 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms.
L ^{b3 ′} represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^{b4 ′} represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms. However, the upper limit of the carbon number of L ^{b3 ′} and L ^{b4 ′} is 20.
L ^{b5 ′} represents a divalent saturated hydrocarbon group having 1 to 22 carbon atoms.
L ^{b6 ′} and L ^{b7 ′} each independently represent a divalent saturated hydrocarbon group having 1 to 22 carbon atoms. However, the upper limit of the carbon number of L ^{b6 ′} and L ^{b7 ′} is 23.
L ^{b8 ′} represents a divalent saturated hydrocarbon group having 1 to 22 carbon atoms.
L ^{b9 ′} and L ^{b10 ′} each independently represent a divalent saturated hydrocarbon group having 1 to 18 carbon atoms. However, the upper limit of the carbon number of L ^{b9 ′} and L ^{b10 ′} is 20.
L ^{b11 ′} represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^{b12 ′} represents a divalent aliphatic saturated hydrocarbon group having 1 to ²¹ carbon atoms. However, the upper limit of the total carbon number of L ^{b11 ′} and L ^{b12 ′} is 21.

Among them, L ^b1 is preferably any one of formula (b1-1 ′) to formula (b1-4 ′), more preferably formula (b1-1 ′) or formula (b1-2 ′), and more preferably formula (b1-1 ′). It is a divalent group represented by (b1-1 ′). Particularly preferred is a divalent group represented by the formula (b1-1 ′) wherein L ^{b2 ′} is a single bond or —CH ₂ —.

Examples of the divalent group represented by formula (b1-1 ′) to formula (b1-5 ′) and formula (b1-7 ′) include the formula (b1-1) to formula (b1-5) and The thing similar to the bivalent group of a formula (b1-7) is mentioned.
Examples of the divalent group represented by the formula (b1-6 ′) include the following in addition to the divalent group represented by the formula (b1-6).

Specific examples when the hydrogen atom contained in the aliphatic saturated hydrocarbon group of L ^b1 is substituted with a fluorine atom or a hydroxy group include the following.

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by the following formulas (Y1) to (Y26).

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

Examples of the substituent for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an oxo group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and carbon. C3-C16 alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C4 acyl group , Glycidyloxy group or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or carbon Represents an aromatic hydrocarbon group of formula 6 to 18. j2 represents an integer of 0 to 4. The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group and the like which are the above substituents may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.

Examples of the halogen atom, aromatic hydrocarbon group, aralkyl group, and acyl group are the same as described above.
Examples of the hydroxy group-containing aliphatic hydrocarbon group include a hydroxymethyl group and a hydroxyethyl group.
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.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, naphthylethyl group and the like.

Examples of Y include the following.

  Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably a substituent (for example, an oxo group, a hydroxy group, etc.). A good adamantyl group, more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

The sulfonate anion in the salt represented by the formula (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-9). In the following formulas, the definitions of the symbols have the same meaning as described above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).
The sulfonate anion in the salt represented by the formula (B1) may be an anion described in JP 2010-204646 A.

Cation Z1 ⁺ contained in the acid generator (B1) include the same as the cation Z ⁺ contained in the above-mentioned formula (II).

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anion and organic cation can be arbitrarily combined, and preferably a combination of any one of anion (b1-1) to anion (b1-1-9) with a cation (Z5) and an anion (b1-1) 3) to any combination of (b1-1-5) and a cation (Z3).

  The acid generator (B1) is preferably a salt represented by the formula (B1-1) to the formula (B1-20), more preferably an acid generator containing an arylsulfonium cation. (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1-11), Formula (B1-12), Formula ( B1-13), a formula (B1-14), a formula (B1-18), a formula (B1-19), or a salt represented by formula (B1-20).

When the resist composition of the present invention contains only the acid generator (II) as an acid generator, the content thereof is preferably 1 part by mass or more (more preferably) with respect to 100 parts by mass of the resin (A). 3 parts by mass or more), preferably 40 parts by mass or less (more preferably 35 parts by mass or less).
Further, when the resist composition of the present invention contains the acid generator (B) in addition to the acid generator (II), the total content of the acid generator (II) and the acid generator (B). Is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 40 parts by mass or less (more preferably 35 parts by mass or less) with respect to 100 parts by mass of the resin (A). In this case, the content ratio (mass) of the acid generator (II) and the acid generator (B) is, for example, 5:95 to 95: 5, preferably 10:90 to 90:10, more preferably 15: 85-85: 15.

<Solvent (E)>
The content of the solvent (E) is, for example, 90% by mass or more in the resist composition, preferably 92% by mass or more, more preferably 94% by mass or more, for example 99.9% by mass or less, preferably 99% by mass or less. It is. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and And esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may contain 1 type independently, and may contain 2 or more types.

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition of the present invention may contain a basic compound (C) that acts as a quencher.
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 formula (C1), R ^c1 , R ^c2 and R ^c3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or 6 to 6 carbon atoms. 10 represents an aromatic hydrocarbon group, and 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, The hydrogen atom contained in the aromatic hydrocarbon group is 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 group having 6 to 10 carbon atoms. It may be substituted with a group hydrocarbon group. ]

［式（Ｃ１−１）中、Ｒ^c2及びＲ^c3は、上記と同じ意味を表す。
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は同一又は相異なる。］

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

［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と同じ意味を表す。
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は同一又は相異なる。］

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

［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と同じ意味を表す。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
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は同一又は相異なり、ｐ３が２以上であるとき、複数のＲ^c15は、同一又は相異なる。
Ｌ^c1は、炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C5) and Formula (C6), R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 each independently represent the same meaning as R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently represent the same meaning as R ^c4 .
o3 and p3 each independently represents an integer of 0 to 3, and when o3 is 2 or more, the plurality of R ^c14 are the same or different, and when p3 is 2 or more, the plurality of R ^c15 are the same or Different.
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と同じ意味を表す。
ｑ３、ｒ３及びｓ３は、それぞれ独立に０〜３の整数を表し、ｑ３が２以上であるとき、複数のＲ^c18は同一又は相異なり、ｒ３が２以上であるとき、複数のＲ^c19は同一又は相異なり、及びｓ３が２以上であるとき、複数のＲ^c20は同一又は相異なる。
Ｌ^c2は、単結合又は炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

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

In the formulas (C1) to (C8), examples of the alkyl group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, the alkoxy group, and the alkanediyl group are the same as those described above.
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

  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- Examples include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl. Piruanirin. Particularly preferred include 2,6-diisopropylaniline.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1, 2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipiconylamine, bipyridine and the like.

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

  The content of the basic compound (C) in the solid content of the resist composition is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably 0.8. It is about 01 to 1% by mass.

<Other components (hereinafter sometimes referred to as “other components (F)”)>
The resist composition of this invention may contain the other component (F) as needed. The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, and the like can be used.

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

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

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

The composition layer is formed by drying the composition after application. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking) or using a decompression device to form a composition layer from which the solvent has been removed. The temperature in this case is preferably about 50 to 200 ° C., for example. The pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various lasers such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do.

  The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.

  The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., and the development time is preferably 5 to 300 seconds.

When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkali developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern.

In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a different type from the organic developer.

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

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

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The structure of the compound was confirmed by MASS (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type).
The weight average molecular weight of the resin is a value determined by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore HXL-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（Ｋ−１）で表される化合物３３．４８部、ジシクロヘキシルカルボジイミド２３．９３部及び塩化メチレン４０部を、反応器に仕込み、混合した。得られた混合物を０℃程度まで冷却した後、式（Ｋ−２）で表される化合物１８．８３部を加え、０℃程度のまま、１時間攪拌した。２３℃まで昇温し、さらに３０分間攪拌した。不溶物をろ過して除去し、得られたろ液を濃縮して、式（Ｋ−３）で表される化合物４４．２８部を得た。 Synthesis Example 1 (Synthesis of monomer (M-K))

33.48 parts of the compound represented by the formula (K-1), 23.93 parts of dicyclohexylcarbodiimide and 40 parts of methylene chloride were charged into a reactor and mixed. After cooling the obtained mixture to about 0 ° C., 18.83 parts of the compound represented by the formula (K-2) was added, and the mixture was stirred for about 1 hour while maintaining about 0 ° C. The temperature was raised to 23 ° C. and the mixture was further stirred for 30 minutes. Insoluble matters were removed by filtration, and the obtained filtrate was concentrated to obtain 44.28 parts of a compound represented by the formula (K-3).

得られた式（Ｋ−３）で表される化合物１９．４２部、式（Ｋ−４）で表される化合物１８．２２部及びアセトニトリル２００部を、反応器に仕込み、混合した。得られた混合物を５０℃で３時間攪拌した。得られた混合物を濃縮し、クロロホルム３００部及びイオン交換水１５０部を加えた後、分液操作により、有機層を回収した。回収された有機層をイオン交換水１５０部で水洗した後、有機層を濃縮した。濃縮物を、カラム分取（カラム分取条件 固定相：メルク社製シリカゲル６０−２００メッシュ 展開溶媒：酢酸エチル）することにより、式（Ｍ−Ｋ）で表される化合物１２．８９部を得た。
ＭＳ（質量分析）：３０８．１（分子イオンピーク）

The reactor was charged with 19.42 parts of the compound represented by the formula (K-3), 18.22 parts of the compound represented by the formula (K-4), and 200 parts of acetonitrile. The resulting mixture was stirred at 50 ° C. for 3 hours. The obtained mixture was concentrated, 300 parts of chloroform and 150 parts of ion-exchanged water were added, and then the organic layer was recovered by a liquid separation operation. The recovered organic layer was washed with 150 parts of ion exchange water, and then the organic layer was concentrated. The concentrate is subjected to column fractionation (column fractionation conditions stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., Ltd. developing solvent: ethyl acetate) to obtain 12.89 parts of a compound represented by the formula (M-K). It was.
MS (mass spectrometry): 308.1 (molecular ion peak)

Synthesis Example 2: Synthesis of salt represented by formula (II-1)

A salt represented by the formula (II-1-a) was synthesized by the method described in JP-A-2007-224008.
10.00 parts of the salt represented by the formula (II-1-a) and 40 parts of 1,2-dichloroethane were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 5.53 parts of the compound represented by the formula (II-1-b) and 0.30 parts of p-toluenesulfonic acid were added, and the mixture was refluxed and stirred at 100 ° C. for 3 hours. The obtained reaction product was cooled to 23 ° C., 120.00 parts of chloroform and 35.39 parts of an 8.7% aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. To the recovered organic layer, 120 parts of ion-exchanged water was charged, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 7 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 20 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To this, 8.14 parts of acetonitrile and 48.84 parts of tert-butyl methyl ether were added and stirred, stirred at 23 ° C. for 1 hour, filtered, and 8.25 of the salt represented by the formula (II-1). Got a part.

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (−) Spectrum): M ⁻ 467.1

式（ＩＩ−２−ｂ）で表される塩を、特開２００８−９４８３５号公報に記載された方法で合成した。
式（ＩＩ−２−ａ）で表される塩１７．５０部、式（ＩＩ−２−ｂ）で表される塩２５．００部(純度：９０．８％)、クロロホルム１２５．００部及びイオン交換水４１．６７部を仕込み、２３℃で１２時間攪拌し、分液を行った。回収された有機層に、イオン交換水３１．２５部を仕込み、攪拌、分液を行った。この水洗を９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。ろ液を濃縮した後、得られた濃縮物に、アセトニトリル５０部を添加して溶解し、濃縮し、得られた残渣にｔｅｒｔ−ブチルメチルエーテル１７３．１３部を加えて攪拌し、ろ過することにより、式（ＩＩ−２−ｃ）で表される塩２８．４２部を得た。 Synthesis Example 3: Synthesis of salt represented by formula (II-2)

A salt represented by the formula (II-2-b) was synthesized by the method described in JP 2008-94835 A.
17.50 parts of the salt represented by the formula (II-2-a), 25.00 parts of the salt represented by the formula (II-2-b) (purity: 90.8%), 125.00 parts of chloroform, 41.67 parts of ion-exchanged water was added, and the mixture was stirred at 23 ° C. for 12 hours for liquid separation. The recovered organic layer was charged with 31.25 parts of ion exchanged water, and stirred and separated. This washing with water was performed nine times. The obtained organic layer was charged with 1.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. Concentrate the filtrate, add 50 parts of acetonitrile to the resulting concentrate, dissolve, concentrate, add 173.13 parts of tert-butyl methyl ether to the resulting residue, stir and filter. Gave 28.42 parts of the salt represented by the formula (II-2-c).

式（ＩＩ−２−ｃ）で表される塩１０．７２部及び１，２−ジクロロエタン４２．８８部を仕込み、２３℃で３０分間攪拌した。その後、式（ＩＩ−１−ｂ）で表される化合物５．５３部及びｐ−トルエンスルホン酸０．３０部を添加し、１００℃で、３時間還流攪拌した。得られた反応物を２３℃まで冷却し、クロロホルム１２０．００部及び８．７％炭酸水素ナトリウム水溶液３５．３９部を加え、２３℃で３０分間攪拌した。その後、静置し、分液した。回収された有機層に、イオン交換水１２０部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を７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、アセトニトリル２０部を添加して溶解し、濃縮した。これに、アセトニトリル９．１２部及びｔｅｒｔ−ブチルメチルエーテル５４．７２部を加えて攪拌し、２３℃で１時間攪拌し、ろ過して、式（ＩＩ−２）で表される塩８．４９部を得た。

10.72 parts of a salt represented by the formula (II-2-c) and 42.88 parts of 1,2-dichloroethane were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 5.53 parts of the compound represented by the formula (II-1-b) and 0.30 parts of p-toluenesulfonic acid were added, and the mixture was refluxed and stirred at 100 ° C. for 3 hours. The obtained reaction product was cooled to 23 ° C., 120.00 parts of chloroform and 35.39 parts of an 8.7% aqueous sodium hydrogen carbonate solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. To the recovered organic layer, 120 parts of ion-exchanged water was charged, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 7 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 20 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To this, 9.12 parts of acetonitrile and 54.72 parts of tert-butyl methyl ether were added and stirred, stirred at 23 ° C. for 1 hour, filtered, and 8.49 of the salt represented by the formula (II-2). Got a part.

MS (ESI (+) Spectrum): M ⁺ 305.1
MS (ESI (−) Spectrum): M ⁻ 467.1

Synthesis Example 4: Synthesis of salt represented by formula (II-3)

  10.00 parts of the compound represented by the formula (II-3-b) obtained by the method described in JP2008-209917A, and the salt 11.26 represented by the formula (II-3-a) Part, chloroform 50 parts and ion-exchanged water 25 parts, and stirred at 23 ° C. for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the resulting residue, the mixture was stirred at 23 ° C. for 30 minutes, and then filtered to obtain the salt 11 represented by the formula (II-3-c). .75 parts were obtained.

式（ＩＩ−３−ｃ）で表される塩１１．７１部、式（ＩＩ−３−ｄ）で表される化合物１．７０部及びモノクロロベンゼン４６．８４部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．１２部を添加した後、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した後、得られた残渣に、クロロホルム５０部及びイオン交換水１２．５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１２．５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を８回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて攪拌した後、ろ過することにより、式（ＩＩ−３−ｅ）で表される塩６．８４部を得た。

11.71 parts of a salt represented by the formula (II-3-c), 1.70 parts of a compound represented by the formula (II-3-d) and 46.84 parts of monochlorobenzene were charged and the mixture was charged at 23 ° C. for 30 minutes. Stir. After adding 0.12 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 12.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 8 times. After concentration of the obtained organic layer, 50 parts of tert-butyl methyl ether was added to the resulting residue, stirred, and then filtered to obtain the salt represented by the formula (II-3-e) 6. 84 parts were obtained.

式（ＩＩ−３−ｅ）で表される塩４．９８部及びクロロホルム２５．００部を仕込み、２３℃で３０分間攪拌した。その後、式（ＩＩ−１−ｂ）で表される化合物２．１７部及び硫酸０．０９部を添加し、６０℃で、１５時間還流攪拌した。得られた反応物を２３℃まで冷却し、イオン交換水１２０部を加え、２３℃で３０分間攪拌した。その後、静置し、分液した。回収された有機層に、イオン交換水１２．５０部を仕込み、２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を７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、アセトニトリル１０部を添加して溶解し、濃縮した。これに、ｔｅｒｔ−ブチルメチルエーテル４１．３５部を加えて攪拌した後、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（ＩＩ−３）で表される塩４．８４部を得た。

4.98 parts of the salt represented by the formula (II-3-e) and 25.00 parts of chloroform were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 2.17 parts of a compound represented by the formula (II-1-b) and 0.09 part of sulfuric acid were added, followed by stirring at 60 ° C. for 15 hours. The obtained reaction product was cooled to 23 ° C., 120 parts of ion exchange water was added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. The recovered organic layer was charged with 12.50 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed 7 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 10 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. To this, 41.35 parts of tert-butyl methyl ether was added and stirred, and then the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 4.84 parts of the salt represented by the formula (II-3).

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (−) Spectrum): M ⁻ 467.1

式（Ｂ１−５−ａ）で表される塩５０．４９部及びクロロホルム２５２．４４部を反応器に仕込み、２３℃で３０分間攪拌した後、式（Ｂ１−５−ｂ）で表される化合物１６．２７部を滴下し、２３℃で１時間攪拌することにより、式（Ｂ１−５−ｃ）で表される塩を含む溶液を得た。得られた式（Ｂ１−５−ｃ）で表される塩を含む溶液に、式（Ｂ１−５−ｄ）で表される塩４８．８０部及びイオン交換水８４．１５部を添加し、２３℃で１２時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、更に、該クロロホルム層にイオン交換水８４．１５部を添加し、水洗した。この操作を５回繰り返した。得られたクロロホルム層に、活性炭３．８８部を添加攪拌し、ろ過した。回収されたろ液を濃縮し、得られた残渣に、アセトニトリル１２５．８７部を添加攪拌し、濃縮した。得られた残渣に、アセトニトリル２０．６２部及びｔｅｒｔ−ブチルメチルエーテル３０９．３０部を加えて２３℃で３０分間攪拌し、上澄み液を除去し、濃縮した。得られた残渣に、ｎ−ヘプタン２００部を添加、２３℃で３０分間攪拌し、ろ過することにより、式（Ｂ１−５）で表される塩６１．５４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ⁺ ３７５．２
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ^- ３３９．１ Synthesis Example 5: Synthesis of salt represented by formula (B1-5)

50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform are charged into a reactor, stirred at 23 ° C. for 30 minutes, and then represented by the formula (B1-5-b). 16.27 parts of the compound was added dropwise and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (B1-5-c). To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the resulting reaction solution was separated into two layers, the chloroform layer was separated and removed, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, and 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and filtered to obtain 61.54 parts of the salt represented by the formula (B1-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ⁻ 339.1

以下、これらのモノマーを、その符号に応じて、「モノマー（Ｍ−Ａ）」〜「モノマー（Ｍ−Ｌ）」という。 Synthesis of Resin (A) Compounds (monomers) used in the synthesis of resin (A) are shown below.

Hereinafter, these monomers are referred to as “monomer (MA)” to “monomer (ML)” depending on the reference numerals.

[Synthesis of Resin A1]
As a monomer, a monomer (MG), a monomer (ME), a monomer (MB), a monomer (M-H), and a monomer (M-K) are used, and the molar ratio [monomer (MG) : Monomer (ME): monomer (MB): monomer (M-H): monomer (M-K)] to be 32: 7: 8: 43: 10 1.5 mass times dioxane was added to make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 6 × 10 ³ resin A1 (copolymer) was obtained with a yield of 80%. This resin A1 has the following structural units.

[Synthesis of Resin A2]
As a monomer, a monomer (MF), a monomer (M-I), a monomer (M-J), a monomer (MD), and a monomer (M-K) are used, and the molar ratio [monomer (MF) : Monomer (M-I): monomer (M-J): monomer (M-D): monomer (M-K)] is mixed to be 45: 14: 2.5: 22.5: 16, Dioxane of 1.5 mass times the total monomer amount was added to make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice, and the weight average molecular weight was 8. 8 × 10 ³ resin A2 (copolymer) was obtained with a yield of 71%. This resin A2 has the following structural units.

[Synthesis of Resin A3]
As a monomer, a monomer (M−F), a monomer (M−I), a monomer (M−J), a monomer (M−D), a monomer (M−H), and a monomer (M−K) are used, and a molar ratio thereof. [Monomer (MF): Monomer (M-I): Monomer (M-J): Monomer (MD): Monomer (M-H): Monomer (M-K)] 45: 14: 2. It mixed so that it might become 5: 17.5: 5: 16, and the dioxane of 1.5 mass times the total monomer amount was added, and it was set as the solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice, and the weight average molecular weight was 8. 3 × 10 ³ resin A3 (copolymer) was obtained with a yield of 69%. This resin A3 has the following structural units.

[Synthesis of Resin A4]
As a monomer, a monomer (MF), a monomer (ML), a monomer (MJ), a monomer (MD), and a monomer (MK) are used, and the molar ratio [monomer (MF) : Monomer (ML): monomer (M-J): monomer (MD): monomer (M-K)] is mixed to be 45: 14: 2.5: 22.5: 16, A solution was prepared by adding propylene glycol monomethyl ether acetate of 1.5 mass times the total monomer amount. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A4 (copolymer) having a molecular weight of 8.2 × 10 ³ was obtained in a yield of 66%. This resin A4 has the following structural units.

[Synthesis of Resin A5]
As a monomer, a monomer (MG), a monomer (ML), a monomer (MB), a monomer (M-H), and a monomer (M-K) are used, and the molar ratio [monomer (MG) : Monomer (ML): monomer (MB): monomer (M-H): monomer (M-K)] to be 32: 7: 8: 43: 10 1.5 mass times propylene glycol monomethyl ether acetate was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A5 (copolymer) having a molecular weight of 7.9 × 10 ³ was obtained in a yield of 82%. This resin A5 has the following structural units.

[Synthesis of Resin H1]
Monomer (MA) and monomer (MC) are used as monomers and mixed so that the molar ratio [monomer (MA): monomer (MC)] is 40:60. An amount of 1.5 mass times dioxane was added to prepare a solution. To the solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.4 mol% and 4.2 mol%, respectively, based on the total monomer amount, and these were added at 70 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 0 × 10 ³ resin H1 (copolymer) was obtained in a yield of 92%. This resin H1 has the following structural units.

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

ＩＩ−２：

ＩＩ−３：

Ｂ１−３：特開２０１０−１５２３４１号公報の実施例に従って合成

Ｂ１−５：

Ｂ２：トリフェニルスルホニウム トリフレート（ＴＰＳ−１０５ ミドリ化学（株）製） <Resin>
A1 to A5, H1: Resin A1 to Resin A5, Resin H1
<Acid generator>
II-1:

II-2:

II-3:

B1-3: synthesized according to the example of JP 2010-152341 A

B1-5:

B2: Triphenylsulfonium triflate (manufactured by TPS-105 Midori Chemical Co., Ltd.)

<Basic compound: Quencher>
C1: 2,6-diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)

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

Examples 1 to 11 and Comparative Example 1
<Manufacture of negative resist pattern>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer, and baked under the conditions of 205 ° C. and 60 seconds, whereby an organic layer having a thickness of 78 nm. An antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness of the composition layer after drying (pre-baking) was 100 nm. After the application, this silicon wafer was pre-baked on a direct hot plate at a temperature described in the “PB” column of Table 1 for 60 seconds to form a composition layer on the silicon wafer. An ArF excimer laser stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized illumination) is applied to a silicon wafer on which the composition layer has been formed. Using a mask for forming a pitch of 100 nm / line width of 50 nm, exposure was performed by changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 1. Next, the composition layer on the silicon wafer was subjected to dynamic dispense development at 23 ° C. for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developer, thereby producing a negative resist pattern. .

  In the obtained resist pattern, the exposure amount at which the line width of the line pattern was 50 nm was defined as effective sensitivity.

<Shape evaluation>
The cross-sectional shape of the line pattern manufactured with effective sensitivity was observed with a scanning electron microscope. A top shape that is close to a rectangle (FIG. 1 (a)) was marked with ◯, and a round top shape (FIG. 1 (b)) was marked with x. The results are shown in Table 2.

Examples 12 to 22 and Comparative Example 2
Except that the developer used in the development process was changed from n-butyl acetate to 2-heptanone (manufactured by Kyowa Hakko Co., Ltd.), the same operation as above was performed to produce a negative resist pattern. Similar evaluations were made. The results are shown in Table 3.

  From the above results, it can be seen that according to the resist composition of the present invention, a negative resist pattern having an excellent shape can be produced.

<Preparation of resist composition>
Each of the components shown below was dissolved in the following solvent in the parts by mass shown in Table 4 and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

Examples 23 to 25 and Comparative Example 3
<Manufacture of positive resist pattern>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 78 nm. An organic antireflection film was formed. Next, the above resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) was 85 nm.
The obtained silicon wafer was pre-baked (PB) for 60 seconds on a direct hot plate at the temperature described in the “PB” column of Table 4. Using the ArF excimer stepper for immersion exposure [XT: 1900Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light] on the wafer on which the resist composition film is formed in this manner, the exposure amount is stepwise. The line and space pattern was subjected to immersion exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking (PEB) was performed for 60 seconds on a hot plate at the temperature described in the “PEB” column of Table 4, and then with an aqueous 2.38 mass% tetramethylammonium hydroxide solution for 60 seconds. Paddle development was performed to obtain a resist pattern.

  In each of the obtained resist pattern films, an exposure amount at which the 50 nm line and space pattern becomes an exposure amount of 1: 1 was defined as an effective sensitivity.

<Shape evaluation>
The cross-sectional shape of the line pattern manufactured with effective sensitivity was observed with a scanning electron microscope. A top shape that is close to a rectangle (FIG. 1 (a)) was marked with ◯, and a round top shape (FIG. 1 (b)) was marked with x. The results are shown in Table 5.

  According to the resist composition of the present invention, a resist pattern having an excellent shape can be produced, and can be used for fine processing of semiconductors.

Claims (5)

A resist composition comprising a resin comprising a structural unit represented by formula (I) and a structural unit having an acid labile group, and an acid generator represented by formula (II).

[In the formula (I),
R ¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
A ¹ is a single bond, ^* —A ² —O—, ^* —A ² —CO—O—, ^* —A ² —CO—O—A ³ —CO—O—, or ^* —A ² —O—CO. -A ³ represents a -O-.
* Represents a bond with -O-.
A ² and A ³ each independently represents an alkanediyl group having 1 to 6 carbon atoms. ]

[In the formula (II),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms, and —CH ₂ — contained in the alicyclic hydrocarbon ring is —O—, —S—, —CO— or —SO _2. -The hydrogen atom contained in the alicyclic hydrocarbon ring may be a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or 6 to 10 carbon atoms. The aromatic hydrocarbon group may be substituted.
R ^f1 and R ^f2 each independently represent a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
s represents an integer of 1 to 10, and when s is 2 or more, a plurality of R ^f1 and R ^f2 are the same or different.
Z ⁺ represents an organic cation. ] The resist composition according to claim 1, wherein the ring W is a ring represented by the formula (IIa1-1), a ring represented by the formula (IIa1-2) or a ring represented by the formula (IIa1-3).

[In Formula (IIa1-1), Formula (IIa1-2) and Formula (IIa1-3),
The methylene group contained in the ring may be replaced by an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group. The hydrogen atom contained in the ring is a hydroxy group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or a carbon number. It may be substituted with an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. ] L ¹ is * —CO—O— (CH ₂ ) _t — (t represents an integer of 0 to 6. * represents a bond to —C (Q ¹ ) (Q ² ) —). The resist composition according to claim 1 or 2.   Furthermore, the resist composition in any one of Claims 1-3 containing a solvent. (1) The process of apply | coating the resist composition in any one of Claims 1-4 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, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including:

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