JP2014026260A - Resist composition and production method of resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition from which a resist pattern with superior pattern collapse resistance can be produced.SOLUTION: The resist composition contains an acid generator expressed by formula (I) and a resin having an acid-labile group. In formula (I), Rand Reach independently represent a hydrocarbon group having 1 to 12 carbon atoms, alkoxy group having 1 to 6 carbon atoms, acyl group having 2 to 7 carbon atoms, acyloxy group having 2 to 7 carbon atoms, alkoxycarbonyl group having 2 to 7 carbon atoms, nitro group or a halogen atom; m and n each independently represent an integer of 0 to 4, and when m is 2 or more, a plurality of Rmay be the same or different from each other, and when n is 2 or more, a plurality of Rmay be the same or different from each other; A- represents an organic anion.

Description

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

また、レジスト組成物から、フォトリソグラフィー技術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）。 A photolithography technique is used for manufacturing a semiconductor element, and a resist composition is used for the photolithography technique. As such a resist composition, for example, Patent Document 1 describes a resist composition containing only the following two compounds as an acid generator.

Further, when forming a resist pattern from a resist composition by a photolithography technique, it is known that 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 2010-197413 A

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

  When a negative resist pattern is produced from the resist composition described in Patent Document 1, pattern collapse resistance (PCM) of the resulting resist pattern may not always be sufficiently satisfied.

［式（Ｉ）中、
Ｒ^１及びＲ^２は、それぞれ独立に、炭素数１〜１２の炭化水素基、炭素数１〜６のアルコキシ基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基、炭素数２〜７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ及びｎは、それぞれ独立に、０〜４の整数を表し、ｍが２以上の場合、複数のＲ^１は互いに同一でも異なってもよく、ｎが２以上の場合、複数のＲ^２は互いに同一でも異なってもよい。
Ａ⁻は、有機アニオンを表す。］
〔２〕酸不安定基を有する樹脂が、２−ヘプタノン及び酢酸ブチルからなる群より選ばれる少なくとも一種を含む現像液に可溶であり、酸の作用により２−ヘプタノン及び酢酸ブチルからなる群より選ばれる少なくとも一種を含む現像液に不溶又は難溶となる樹脂である前記〔１〕記載のレジスト組成物。
〔３〕前記式（Ｉ）のＡ⁻が、有機スルホン酸アニオン、有機スルホンアミドアニオン、有機スルホンイミドアニオン又は有機カルボン酸アニオンである前記〔１〕又は〔２〕記載のレジスト組成物。
〔４〕前記式（Ｉ）のＡ⁻が、式（Ｉ−Ａ）で表されるアニオンである前記〔１〕又は〔２〕記載のレジスト組成物。

［式（Ｉ−Ａ）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価の炭素数１〜１７の脂肪族飽和炭化水素基を表し、該２価の脂肪族飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該アルキル基及び該脂環式炭化水素基を構成するメチレン基は、酸素原子、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。］
〔５〕さらに、溶剤を含有する〔１〕〜〔４〕のいずれか一つ記載のレジスト組成物。
〔６〕さらに、式（Ｉ）で表される酸発生剤以外の酸発生剤を含有する〔１〕〜〔５〕のいずれか一つ記載のレジスト組成物。
〔７〕さらに、式（ＩＩ）で表される化合物を含有する前記〔１〕〜〔６〕のいずれか一つ記載のレジスト組成物。

［式（ＩＩ）中、
Ｒ^Ｄ１及びＲ^Ｄ２は、それぞれ独立に、炭素数１〜１２の炭化水素基、炭素数１〜６のアルコキシ基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基、炭素数２〜７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、それぞれ独立に、０〜４の整数を表し、ｍ’が２以上の場合、複数のＲ^Ｄ１は互いに同一でも異なってもよく、ｎ’が２以上の場合、複数のＲ^Ｄ２は互いに同一でも異なってもよい］
〔８〕（１）前記〔１〕〜〔７〕のいずれか一つ記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程、
を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A resist composition containing an acid generator represented by the formula (I) and a resin having an acid labile group.

[In the formula (I),
R ¹ and R ² are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number. Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m and n each independently represents an integer of 0 to 4, and when m is 2 or more, the plurality of R ¹ may be the same or different from each other. When n is 2 or more, the plurality of R ² are It may be the same or different.
A ⁻ represents an organic anion. ]
[2] A resin having an acid labile group is soluble in a developer containing at least one selected from the group consisting of 2-heptanone and butyl acetate, and from the group consisting of 2-heptanone and butyl acetate by the action of an acid [1] The resist composition according to [1], which is a resin that is insoluble or hardly soluble in a developer containing at least one selected.
[3] The resist composition according to [1] or [2], wherein A ^{− in the} formula (I) is an organic sulfonate anion, an organic sulfonamide anion, an organic sulfonimide anion, or an organic carboxylate anion.
[4] The resist composition according to [1] or [2], wherein A ⁻ in the formula (I) is an anion represented by the formula (IA).

[In the formula (IA),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group. May be.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. The methylene group constituting the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. ]
[5] The resist composition according to any one of [1] to [4], further containing a solvent.
[6] The resist composition according to any one of [1] to [5], further comprising an acid generator other than the acid generator represented by formula (I).
[7] The resist composition according to any one of [1] to [6], further comprising a compound represented by the formula (II).

[In the formula (II),
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m ′ and n ′ each independently represents an integer of 0 to 4, and when m ′ is 2 or more, a plurality of R ^D1s may be the same or different from each other, and when n ′ is 2 or more, a plurality of R ^D2 may be the same or different from each other]
[8] (1) A step of applying the resist composition according to any one of [1] to [7] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including:

  If the resist composition of this invention is used, the resist pattern which has the outstanding pattern collapse tolerance can be manufactured.

In the present specification, "(meth) acrylic monomer" 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 (hereinafter sometimes referred to as “the present resist composition”) is an acid generator represented by the formula (I) (hereinafter sometimes referred to as “acid generator (I)”). And a resin having an acid labile group (hereinafter sometimes referred to as “resin (A)”).
The resist composition preferably further contains a solvent (hereinafter sometimes referred to as “solvent (D)”).
The resist composition preferably further contains a compound represented by the above formula (II) (hereinafter sometimes referred to as “compound (II)”).
The resist composition preferably further contains an acid generator other than the acid generator (I).
The resist composition preferably further contains a basic compound (hereinafter sometimes referred to as “basic compound (C)”).

［式（Ｉ）中、
Ｒ^１及びＲ^２は、それぞれ独立に、炭素数１〜１２の炭化水素基、炭素数１〜６のアルコキシ基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基、炭素数２〜７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ及びｎは、それぞれ独立に、０〜４の整数を表し、ｍが２以上の場合、複数のＲ^１のは互いに同一でも異なってもよく、ｎが２以上の場合、複数のＲ^２は互いに同一でも異なってもよい。
Ａ⁻は、有機アニオンを表す。］
なお、以下の説明において、酸発生剤（Ｉ）を構成するカチオンを、場合により「カチオン（Ｉ）」という。 <Acid generator (I)>
The acid generator (I) is a salt represented by the formula (I). In the present resist composition, the acid generator (I) may be used alone or in combination of two or more.

[In the formula (I),
R ¹ and R ² are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number. Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m and n each independently represents an integer of 0 to 4. When m is 2 or more, a plurality of R ¹ s may be the same as or different from each other. When n is 2 or more, a plurality of R ² are They may be the same or different.
A ⁻ represents an organic anion. ]
In the following description, the cation constituting the acid generator (I) is sometimes referred to as “cation (I)”.

Examples of the hydrocarbon group having 1 to 12 carbon atoms include an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 12 carbon atoms, and these And a group having 4 to 12 carbon atoms in combination. Preferably, it is a C1-C6 hydrocarbon group.
Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, and a dodecyl group.
Examples of the alicyclic hydrocarbon group include a cyclopropyl group, a cycloisopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, a decahydronaphthyl group, a norbornyl group, and an adamantyl group. Is mentioned.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group, phenanthryl group. , Aryl groups such as 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl.
Examples of the group in which the aliphatic hydrocarbon group and the alicyclic hydrocarbon group are combined include an alkyl-cycloalkyl group and a cycloalkyl-alkyl group.
Examples of the group combining an aliphatic hydrocarbon group and an aromatic hydrocarbon group include an aralkyl group (for example, a phenylmethyl group, a 1-phenylethyl group, a 2-phenylethyl group, a 1-phenyl-1-propyl group). Group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl -1-hexyl group).

Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group. Preferably, it is a C1-C4 alkoxy group.
Examples of the acyl group having 2 to 7 carbon atoms include acetyl group, propionyl group, butyryl group, valeryl group, hexanoyl group, heptanoyl group, and benzoyl group. Preferably, it is a C2-C5 acyl group.
Examples of the acyloxy group having 2 to 7 carbon atoms include an acetoxy group, a propionyloxy group, a butyryloxy group, an isobutyryloxy group, a benzoyloxy group, and the like. Preferably, it is a C2-C5 acyloxy group.
Examples of the C2-C7 alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group, a pentyloxycarbonyl group, and a hexyloxycarbonyl group. Preferably, it is a C2-C5 alkoxycarbonyl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom, a chlorine atom and a bromine atom are preferable.

R ¹ and R ² in formula (I) are each independently a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an acyl group having 2 to 5 carbon atoms, or a group having 2 to 5 carbon atoms. An acyloxy group, an alkoxycarbonyl group having 2 to 5 carbon atoms, a nitro group, or a halogen atom is preferable.
m and n are each independently preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and still more preferably 0.

  Specific examples of the cation (I) include cations represented by the following formulas (Ic-1) to (Ic-21), respectively.

A ^- organic anion that represent is usually an organic anion capable of generating an acid represented by A-H from the acid generator (I) by exposure, for example, an organic sulfonic acid anion, organic sulfonamide anion, organic sulfonyl Examples thereof include an imide anion, an organic sulfonylmethide anion, and an organic carboxylate anion. Among these, an organic sulfonate anion, an organic sulfonamide anion, an organic sulfonylimide anion and an organic carboxylate anion are preferable, an organic sulfonate anion is more preferable, and a perfluoroalkanesulfonate anion and the following formula (IA) are represented. More preferred is an anion.

  Examples of perfluoroalkanesulfonic acid anions include trifluoromethanesulfonic acid anion, perfluoroethanesulfonic acid anion, perfluoropropanesulfonic acid anion, perfluorobutanesulfonic acid anion, among which trifluoromethanesulfonic acid anion and perfluoroethanesulfonic acid anion. Is more preferable.

［式（Ｉ−Ａ）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価の炭素数１〜１７の脂肪族飽和炭化水素基を表し、該２価の脂肪族飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該アルキル基及び該脂環式炭化水素基を構成するメチレン基は、酸素原子、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。］

[In the formula (IA),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group. May be.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. The methylene group constituting the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. ]

The perfluoroalkyl group of Q ¹ and Q ² is ^{one in} which all hydrogen atoms contained in the alkyl group are replaced with fluorine atoms. Specifically, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, Examples include a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group.
Q ¹ and Q ² are each independently preferably a fluorine atom or a trifluoromethyl group, more preferably a fluorine atom.

多環式の脂環式飽和炭化水素基としては、例えば、式（ＫＡ−８）〜式（ＫＡ−２２）のいずれかで表される脂環式炭化水素から水素原子を２個取り去った基等が挙げられる。

Examples of the divalent aliphatic saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic alicyclic saturated hydrocarbon group. Two or more of them may be combined. .
Examples of the linear alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5- Diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane- 1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl Group, heptadecane-1,17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group.
Examples of the branched alkanediyl group include 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, and pentane-1,4. -A diyl group, 2-methylbutane-1, 4-diyl group, etc. are mentioned.
Examples of the monocyclic alicyclic saturated hydrocarbon group include groups in which two hydrogen atoms have been removed from the alicyclic hydrocarbon represented by any one of the formulas (KA-1) to (KA-7). Etc.

Examples of the polycyclic alicyclic saturated hydrocarbon group include groups in which two hydrogen atoms have been removed from an alicyclic hydrocarbon represented by any one of formulas (KA-8) to (KA-22). Etc.

式（ｂ１−１）〜式（ｂ１−７）中、
Ｌ^b2は、単結合又は炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の脂肪族飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の２価の脂肪族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、単結合又は炭素数１〜１４の２価の脂肪族飽和炭化水素基を表す。
Ｌ^b６は、炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。但しＬ^b5及びＬ^b6の合計炭素数の上限は１５である。
Ｌ^b７は、単結合又は炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^b８は、炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。但しＬ^b７及びＬ^b８の合計炭素数の上限は１６である。
Ｌ^b9は、単結合又は炭素数１〜１３の２価の脂肪族飽和炭化水素基を表す。
Ｌ^b10は、炭素数１〜１４の２価の脂肪族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１４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１〜１１の２価の脂肪族飽和炭化水素基を表す。
Ｌ^b13は、炭素数１〜１２の２価の脂肪族飽和炭化水素基を表す。但しＬ^b11、Ｌ^b12及びＬ^b13の合計炭素数の上限は１２である。
Ｌ^b14及びＬ^b15は、それぞれ独立に、単結合又は炭素数１〜１３の２価の脂肪族飽和炭化水素基を表す。
Ｌ^b16は、炭素数１〜１４の２価の脂肪族飽和炭化水素基を表す。但しＬ^b14、Ｌ^b15及びＬ^b16の合計炭素数の上限は１４である。 Specific examples of the group in which the methylene group constituting the aliphatic saturated hydrocarbon group of L ^b1 is replaced with an oxygen atom or a carbonyl group include, for example, any one of formulas (b1-1) to (b1-7) And the group represented. L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4), more preferably a group represented by formula (b1-1) or formula (b1-3). It is. In addition, Formula (b1-1)-Formula (b1-7) has described the right and left according to Formula (IA), and it is C on the left side among the two bonds represented by *, respectively. It is combined with (Q ¹ ) (Q ² ). The same applies to specific examples of formula (b1-1) to formula (b1-7) shown below.

In formula (b1-1) to formula (b1-7),
L ^b2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent aliphatic 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 single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b6 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b5 and L ^b6 is 15.
L ^b7 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b8 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, the upper limit of the total carbon number of L ^b7 and L ^b8 is 16.
L ^b9 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b10 represents a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 14.
L ^b11 and L ^b12 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 11 carbon atoms.
L ^b13 represents a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b11 , L ^b12 and L ^b13 is 12.
L ^b14 and L ^b15 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b16 represents a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b14 , L ^b15 and L ^b16 is 14.

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.

Examples of the alkyl group for Y include methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, hexadecyl, pentadecyl, hexyldecyl. Group, heptadecyl group, octadecyl group and the like. Of these, an alkyl group having 1 to 6 carbon atoms is preferable. Further, the methylene group constituting the alkyl group may be replaced with an oxygen atom, a carbonyl group or a sulfonyl group.
Examples of the alicyclic hydrocarbon group for Y include a group in which one hydrogen atom has been removed from the alicyclic hydrocarbon represented by any of the above formulas (KA-1) to (KA-22). Can be mentioned. Among them, as the alicyclic hydrocarbon group for Y, groups represented by formulas (Y1) to (Y11) are preferable, and a methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, a carbonyl group, or As the group replaced with a sulfonyl group, groups represented by the following formulas (Y12) to (Y26) are preferable.

  Y is preferably an alicyclic hydrocarbon group, more preferably a group represented by any one of formulas (Y1) to (Y26), and a group represented by any one of formulas (Y1) to (Y19). The group represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19) is particularly more preferred, and the group represented by formula (Y11) or formula (Y14) is particularly preferred.

Examples of the substituent that the alkyl group and alicyclic hydrocarbon group of Y optionally have include a halogen atom, a hydroxy group; an alkyl group, an alicyclic hydrocarbon group, a halogen atom, or a hydroxy group. An aromatic hydrocarbon group having 6 to 18 carbon atoms; an acyl group having 2 to 4 carbon atoms; a glycidyloxy group; or a — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is the number of carbon atoms) Represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4). . When Y is an alicyclic hydrocarbon group, it may have an alkyl group having 1 to 6 carbon atoms and / or an aralkyl group having 7 to 12 carbon atoms as a substituent.

As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group, which may be linear or branched.
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, Examples include a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of the anion represented by the formula (IA) include organic anions described in JP 2010-204646 A, and preferably an anion represented by the following formula.

In the acid generator (I), the above cation (I) and the above organic anion (A ⁻ ) can be arbitrarily combined. The anion represented by the formula (Ia-1) is represented as “(Ia-1)” or the like according to the formula number, and specific examples of the acid generator (I) are shown in Table 1. . In Table 1, a cation or the like represented by the formula (Ic-1) is represented as “(Ic-1)” or the like according to the formula number.

  Of the above acid generators (I), more preferable ones are as follows. These are also preferable in that they can be easily produced using readily available raw materials by the method for producing the acid generator (I) described later.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
溶剤としては、プロピレングルコールモノメチルエーテルアセテート、モノクロロベンゼン等が用いられる。 The acid generator (I) can be produced by reacting the salt represented by the formula (Ia) and the compound represented by the formula (Ib) in the presence of a catalyst in a solvent. .

(In the formula, all symbols have the same meaning as described above.)
As the solvent, propylene glycol monomethyl ether acetate, monochlorobenzene or the like is used.

Examples of the salt represented by the formula (Ia) include those represented by the following.

Examples of the compound represented by the formula (Ib) include trifluoromethanesulfonic acid, perfluoroethanesulfonic acid, and those represented by the following.

<Acid generator other than acid generator (I)>
The acid generator other than the acid generator (I) (hereinafter, sometimes referred to as “acid generator (B)”) may be either an ionic acid generator or a nonionic generator. Agents are preferred.

Examples of the acid generator (B) include salts represented by formulas (B1-1) to (B1-24), respectively. Among them, a salt containing a triarylsulfonium cation is preferable. Formula (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1- 11), formula (B1-12), formula (B1-13), formula (B1-14), formula (B1-18), formula (B1-19), formula (B1-20)), formula (B1-21) ), Formula (B1-22), formula (B1-23) and salt represented by formula (B1-24), respectively.

  5 mass parts or more are preferable with respect to the total amount of an acid generator, and, as for the content rate of acid generator (I), 10 mass parts or more are more preferable.

  The content ratio of the acid generator in the present resist composition is preferably 40% by mass or less, more preferably 35% by mass or less, preferably 1% by mass or more, more preferably 3% by mass or more, based on the solid content. It is.

<Resin (A)>
The resin (A) is a resin having an acid labile group. In the present specification, the “acid labile group” is a group having a leaving group, and the leaving group is eliminated upon contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). means. The resin (A) is preferably a resin having a structural unit containing an acid labile group (hereinafter sometimes referred to as “structural unit (a1)”).
Further, the resin (A) is further decomposed by the action of an acid, and has a characteristic that the solubility in a developer containing at least one selected from the group consisting of 2-heptanone and butyl acetate is reduced (hereinafter sometimes referred to as “acid”). It is preferable to have an “operating characteristic”.

［式（１）中、
Ｒ^a1〜Ｒ^a3は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組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１価の炭化水素基を表し、Ｒ^a3’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a2’及びＲ^a3’は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。該１価の炭化水素基及び該２価の炭化水素基を構成するメチレン基は、酸素原子又は硫黄原子に置き換わってもよい。＊は結合手を表す。］ <Acid labile group>
Examples of the acid labile group include a group represented by the formula (1) (hereinafter sometimes referred to as “group (1)”) and a group represented by the formula (2) (hereinafter sometimes referred to as “group ( 2) ")) and the like.

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

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

アルキル基と脂環式炭化水素基とを組み合わせた基としては、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。 ^Examples of the alkyl group represented by R ^{a1 to} R ^{a3 in} the group (1) 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 to} R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond). The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms. In the range of each carbon number, those already exemplified are included. However, carbon number of this alicyclic hydrocarbon group becomes like this. Preferably it is the range of 3-16.

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

Examples of the group represented by —C (R ^a1 ) (R ^a2 ) (R ^a3 ) when 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. * Represents a bond with -O-.

Examples of the group (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are alkyl groups, preferably tert-butyl group), 2-alkyladamantane-2 -Yloxycarbonyl group (in formula (1), R ^a1 and R ^a2 are bonded to form an adamantane-2-yl ring, 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 adamantan-1-yl group).

The hydrocarbon group of R ^{a1 ′} and R ^{a2 ′ in} the group (2) is, for example, an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group 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 groups in which one hydrogen atom has been removed from the hydrocarbon groups of R ^{a1 ′ to} R ^{a3 ′} .

In formula (2), at least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

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

<Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”). Such monomer (a1) preferably has an acid labile group and a carbon-carbon double bond, more preferably a (meth) acrylic monomer having an acid labile group, and group (1) and / or group ( A (meth) acrylic monomer having 2) is more preferred.

  Of the (meth) acrylic monomers having an acid labile group, the monomer (a1) having an alicyclic hydrocarbon group having 5 to 20 carbon atoms is preferred. Since the resin (A) obtained using such a monomer (a1) has a bulky structure such as an alicyclic hydrocarbon group, the present resist composition containing the resin (A) is obtained. There exists a tendency for the resolution of the resist pattern manufactured using it to become still better.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、酸素原子又は＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−で表される基を表し、ｋ１は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１０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。
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。］ As the structural unit (a1), a structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as “structural unit (a1-1)”) or a structural unit represented by the formula (a1-2) (Hereinafter, it is sometimes referred to as “structural unit (a1-2)”). Such resin (A1) may have the structural unit (a1-1) as a single species, may have multiple types, or may have the structural unit (a1-2) as a single species. In addition, a plurality of types may be included, and the structural unit (a1-1) and the structural unit (a1-2) may be combined.

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent an oxygen atom or a group represented by * —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a carbonyl group It represents a bond with (—CO—).
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or a combination thereof.
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 an oxygen atom or a group represented by * —O— (CH ₂ ) _k1 —CO—O—, and more preferably an oxygen atom. k1 is preferably an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and a group obtained by combining these include the same groups as those described for R ^{a1 to} R ^a3 in formula (1).
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group of R ^a6 and R ^a7 preferably has 8 or less carbon atoms, more preferably 6 or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As the structural unit (a1-1), structural units respectively represented by formula (a1-1-1) to formula (a1-1-8) are preferable, and formula (a1-1-1) to formula (a1- The structural units represented by 1-4) are more preferable.

  Examples of the monomer (a1) for deriving these structural units (a1-1) include those described in JP-A No. 2010-204646.

As the structural unit (a1-2), those represented by formulas (a1-2-1) to (a1-2-12) are preferable, and formulas (a1-2-3) and (a1-2-2) are preferable. 4), structural units each represented by formula (a1-2-9) or (a1-2-10) are more preferred, each represented by formula (a1-2-3) or (a1-2-9) More preferred are structural units.

  Examples of the monomer (a1) capable of deriving the structural unit (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethyl. Examples include cycloheptan-1-yl (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, and 1-isopropylcyclopentan-1-yl (meth) acrylate.

When the resin (A) has the structural unit (a1-1) and / or the structural unit (a1-2) as the structural unit (a1), the total content ratio thereof is based on the total structural unit of the resin (A). Usually, it is 10-95 mol%, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%, More preferably, it is 20-60 mol%.
When the structural unit (a1) has a structural unit (a1) having an adamantane-2-yl group (preferably the structural unit (a1-1)), the structural unit (a1) in the resin (A) ) Is preferably 15 mol% or more of the structural unit (a1) having an adamantane-2-yl group. With such a content ratio, the resin (A) having the structural unit (a1) having an adamantane-2-yl group has a resistance to dry etching of a resist pattern produced from a resist composition containing the resin (A). There is a tendency to be good. In addition, in order to make the total content rate of a structural unit (a1-1) and / or a structural unit (a1-2) into the above-mentioned range, when manufacturing resin (A), it is with respect to the usage-amount of all monomers. What is necessary is just to adjust the usage-amount of the monomer which induces | guides | derives a structural unit (a1-1) and / or a structural unit (a1-2).

  The resin (A) may have a structural unit (a1) other than the structural unit (a1-1) and the structural unit (a1-2) which are suitable structural units (a1).

  Furthermore, as the structural unit (a1), a monomer represented by the following formula (a1-3) to formula (a1-5) (hereinafter, “monomer (a1-3)” or the like depending on the formula number depending on the case) And the structural unit derived from.

［式（ａ１−３）中、
Ｒ^a9は、水素原子、置換基を有していてもよい炭素数１〜３の脂肪族炭化水素基、カルボキシ基、シアノ基、又は−ＣＯＯＲ^a13で表される基を表し、Ｒ^a13は、炭素数１〜８の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子はヒドロキシ基等で置換されていてもよく、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。Ｒ^a10、Ｒ^a11及びＲ^a12は、それぞれ独立に、炭素数１〜１２の脂肪族炭化水素基を表すか、或いはＲ^a10及びＲ^a11は互いに結合して環を形成している。該脂肪族炭化水素基及に含まれる水素原子はヒドロキシ基等で置換されていてもよく、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］
モノマー（ａ１−３）に由来する構造単位を有する樹脂（Ａ）は、その主鎖に剛直なノルボルナン環を含むものとなるので、このような樹脂（Ａ）を含有する本レジスト組成物は、ドライエッチング耐性に優れたレジストパターンを製造できる傾向がある。

[In the formula (a1-3),
R ^a9 is hydrogen atom, an aliphatic hydrocarbon group having carbon atoms of 1 to 3 may have a substituent, a carboxy group, a cyano group, or a group represented by -COOR ^a13, R ^a13 is Represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, a hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and a methylene group constituting the aliphatic hydrocarbon group is: An oxygen atom or a carbonyl group may be substituted. R ^a10 , R ^a11 and R ^a12 each independently represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or R ^a10 and R ^a11 are bonded to each other to form a ring. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]
Since the resin (A) having a structural unit derived from the monomer (a1-3) contains a rigid norbornane ring in its main chain, the present resist composition containing such a resin (A) is: There is a tendency that a resist pattern having excellent dry etching resistance can be produced.

Examples of the aliphatic hydrocarbon group represented by R ^a9 include an alkyl group, specifically, a methyl group, an ethyl group, a propyl group, and the like. Examples of the substituent, particularly an aliphatic hydrocarbon group (alkyl group) having a hydroxy group include a hydroxymethyl group and a 2-hydroxyethyl group. ^Examples of the group represented by R ^a13 include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.

Examples of the aliphatic hydrocarbon group represented by R ^{a10 to} R ^a12 include an alkyl group, specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group. Group, dodecyl group and the like. The ring formed by combining R ^a10 and R ^a11 together with the carbon atom to which they are bonded is a cyclohexane ring, an adamantane ring, or the like.

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

  When the resin (A) has a structural unit derived from the monomer (a1-3), the content ratio is preferably 10 to 95 mol% with respect to all the structural units of the resin (A), and 15 to 90 mol. % Is more preferable, and 20 to 85 mol% is more preferable. The content ratio of the structural unit derived from the monomer (a1-3) is selected so as not to significantly impair the acid action characteristics of the resin (A).

［式（ａ１−４）中、
Ｒ¹⁰は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
ｌ^ａは０〜４の整数を表す。
Ｒ¹¹は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表し、ｌ^ａが２以上である場合、複数のＲ¹¹の全部又は一部は同じであってもよい。
Ｒ¹²及びＲ¹³はそれぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｘ^a2は、置換基を有していてもよい炭素数１〜１７の脂肪族炭化水素基又は単結合を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子、硫黄原子、カルボニル基、スルホニル基又は−Ｎ（Ｒ^ｃ）−（ただし、Ｒ^ｃは、水素原子又は炭素数１〜６のアルキル基を表す）で表される基に置き換わっていてもよい。
Ｙ^a3は、置換基を有していてもよい炭素数１〜１８の炭化水素基を表す。］ The monomer (a1-4) is represented by the formula (a1-4).

[In the formula (a1-4),
R ¹⁰ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
l ^a represents an integer of 0 to 4;
R ¹¹ is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group, or methacryloyl. In the case where l ^a is 2 or more, all or a part of the plurality of R ¹¹ may be the same.
R ¹² and R ¹³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
X ^a2 represents an ^optionally substituted aliphatic hydrocarbon group having 1 to 17 carbon atoms or a single bond, and the methylene group constituting the aliphatic hydrocarbon group includes an oxygen atom, a sulfur atom, a carbonyl A group, a sulfonyl group, or a group represented by —N (R ^c ) — (wherein R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) may be substituted.
Y ^a3 represents an ^optionally substituted hydrocarbon group having 1 to 18 carbon atoms. ]

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group for R ¹⁰ 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 of R ¹⁰ 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 ¹⁰ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

Examples of the alkoxy group for R ¹¹ include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group. Especially, a C1-C4 alkoxy group is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is further more preferable.
Examples of the acyl group for R ¹¹ include an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group for R ¹¹ include an acetyloxy group, a propionyloxy group, a butyryloxy group, and an isobutyryloxy group.
The hydrocarbon group of R ¹² , R ¹³ and Y ^a3 may be chain or cyclic, and examples thereof include the same groups as those described for R ^{a1 ′ to} R ^{a3 ′} in formula (2).
Examples of the aliphatic hydrocarbon group for X ^a2 include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, and a divalent group obtained by combining these groups. For example, R in the formula (1) alkyl groups ^a1 to R ^a3, hydrogen atom from an alicyclic hydrocarbon group or a group formed by combining these, and the like one excluded groups.

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

  When the resin (A) has a structural unit derived from the monomer (a1-4), the content ratio is preferably 10 to 95 mol% with respect to all the structural units of the resin (A), and 15 to 90 mol%. Is more preferable, and 20-85 mol% is further more preferable. The content ratio of the structural unit derived from the monomer (a1-4) is selected so as not to significantly impair the acid action characteristics of the resin (A).

式（ａ１−５）中、
Ｒ^３１は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｌ^１は、酸素原子、硫黄原子又は＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−で表される基を表す。ここで、ｋ２は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手である。
Ｌ^２及びＬ^３は、それぞれ独立して、酸素原子又は硫黄原子を表す。
Ｚ^１は、単結合又は炭素数１〜６のアルカンジイル基を表し、該アルカンジイル基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ｓ１及びｓ１’は、それぞれ独立して、０〜４の整数を表す。 The monomer (a1-5) is a (meth) acrylic monomer having an acid labile group (2), and is represented by the formula (a1-5).

In formula (a1-5),
R ³¹ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
L ¹ represents an oxygen atom, a sulfur atom or a group represented by * —O— (CH ₂ ) _k2 —CO—O—. Here, k2 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
L ² and L ³ each independently represent an oxygen atom or a sulfur atom.
Z ¹ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
s1 and s1 ′ each independently represents an integer of 0 to 4.

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ¹ is preferably an oxygen atom.
One of L ² and L ³ 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 ¹ 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 1 to 50 mol%, preferably 3 to 40 mol based on all structural units of the resin (A1). % Is more preferable, and 5 to 30 mol% is more preferable.

<Structural unit without acid labile group>
In addition to the structural unit (a1), the resin (A) is a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”, and a monomer for deriving the structural unit (s), It is preferable to have “monomer (s)”. Resin (A) may have only 1 type or multiple types of structural units (s).

  When resin (A) has a structural unit (s), the content rate of a structural unit (s) becomes like this. Preferably it is 10-80 mol% with respect to all the structural units of resin (A), More preferably, it is 20-60. Mol%. When such a resin (A) is used in the present resist composition, the resulting resist pattern tends to have a better dry etching resistance.

  The structural unit (s) preferably has a hydroxy group and does not have an acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring. And a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (a3)”). When the resin (A) has these structural units, the adhesion between the composition layer formed on the substrate and the substrate is excellent, and thus a high-resolution resist pattern tends to be obtained.

<Structural unit (a2)>
The structural unit (a2) is preferably selected according to the type of exposure light source used when producing the resist pattern. When an ArF excimer laser (wavelength: 193 nm) is used as the exposure light source, the structural unit (a2) having an alcoholic hydroxy group is preferable as the structural unit (a2).
When a KrF excimer laser (wavelength: 248 nm) or a high energy beam such as an electron beam or EUV light is used as the exposure light source, the structural unit (a2) has a phenolic hydroxy group as the structural unit (a2). Is preferred. In this specification, irradiation with radiation such as an electron beam may be collectively referred to as “exposure”.
Resin (A) may have only 1 type, or 2 or more types of structural units (a2).

式（ａ２−１）中、
Ｌ^a3は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手を表す。）で表される基を表す。
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。 As the structural unit (a2) having an alcoholic hydroxy group, a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”) and a formula (a2-0) (Hereinafter, referred to as “structural unit (a2-0)” in some cases).

In formula (a2-1),
L ^a3 is an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7, and * represents a bond to a carbonyl group (—CO—)). Represents the group represented.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10.

L ^a3 is preferably an oxygen atom or a group represented by —O— (CH ₂ ) _k3 —CO—O—, wherein k3 is an integer of 1 to 4, more preferably an oxygen atom or — O—CH ₂ —CO—O—, more preferably an oxygen atom.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

As the structural unit (a2-1), for example, the following can be mentioned, and preferably the formula (a2-1-1), the formula (a2-1-2), the formula (a2-1-3) and the formula (a a2-1-4), and more preferably a structural unit represented by the formula (a2-1-1) or (a2-1-3).

  The structural unit (a2-1) is derived from, for example, an acid stable monomer described in JP2010-204646A.

  When the resin (A) has a structural unit (a2-1), the content is preferably 1 to 45 mol%, more preferably 1 to 40 mol%, based on all structural units of the resin (A). 2 to 35 mol% is more preferable.

式（ａ２−０）中、
Ｒ^a30は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^a31は同一でも異なっていてもよい。 Examples of the structural unit (a2) having a phenolic hydroxy group include a structural unit represented by the formula (a2-0) (hereinafter sometimes referred to as “structural unit (a2-0)”).

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

^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom for R ^a30 include the same groups as those described for R ¹⁰ in formula (a1-4). Among these, R ^a30 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group.
Examples of the alkoxy group for R ^a31 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group. An alkoxy group having 1 to 4 carbon atoms is preferable, and a methoxy group and an ethoxy group Is more preferable, and a methoxy group is more preferable.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and still more preferably 0.

Among the structural units (a2-0), any one of the following formula (a2-0-1), formula (a2-0-2), formula (a2-0-3) and formula (a2-0-4) The thing represented by these is preferable. A monomer for deriving such a structural unit is described in, for example, JP-A No. 2010-204634.

  The resin (A) containing the structural unit (a2-0) uses a monomer obtained by protecting a phenolic hydroxy group of a monomer that induces the structural unit (a2-0) with a protective group such as an acetyl group. It can be produced by conducting a polymerization reaction and then deprotecting. However, when the deprotection treatment is performed, the acid labile group of the structural unit (a) needs to be not significantly impaired.

  When the resin (A) has the structural unit (a2-0), the content is preferably from 5 to 90 mol%, more preferably from 10 to 85 mol%, based on all the structural units of the resin (A). 15-80 mol% is more preferable.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be monocyclic such as β-propiolactone ring, γ-butyrolactone ring and δ-valerolactone ring, and may be a monocyclic lactone ring and other rings. A condensed ring may be used. Among these lactone rings, a γ-butyrolactone ring, a condensed ring of a γ-butyrolactone ring and another ring, and an adamantane lactone ring are preferable.

［式（ａ３−１）中、
Ｌ^a4は、酸素原子又は＊−Ｏ−（ＣＨ₂）_k4−ＣＯ−Ｏ−（ｋ４は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a18は、水素原子又はメチル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a21は炭素数１〜４の脂肪族炭化水素基を表し、ｐ１が２以上の場合、複数のＲ^a21は同じであってもよい。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は＊−Ｏ−（ＣＨ₂）_k4−ＣＯ−Ｏ−（ｋ４は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
ｑ１は、０〜３の整数を表す。
Ｒ^a22は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表し、ｑ１が２以上の場合、複数のＲ^a22は同じであってもよい。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は＊−Ｏ−（ＣＨ₂）_k4−ＣＯ−Ｏ−（ｋ４は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a20は、水素原子又はメチル基を表す。
ｒ１は、０〜３の整数を表す。
Ｒ^a23は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表し、ｒ１が２以上の場合、複数のＲ^a23は同じであってもよい。
式（ａ３−４）中、
Ｌ^a７は、酸素原子、＊−Ｏ−（ＣＨ₂）_k4−Ｏ−、＊−Ｏ−（ＣＨ₂）_k4−ＣＯ−Ｏ−、＊−Ｏ−（ＣＨ₂）_k4−ＣＯ−Ｏ−（ＣＨ₂）_k５−ＣＯ−Ｏ−又は＊−Ｏ−（ＣＨ₂）_k4−Ｏ−ＣＯ−（ＣＨ₂）_k５−Ｏ−（ｋ４及びｋ５は、それぞれ独立に、１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a2４は、水素原子又はメチル基を表す。］ The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3) or the formula (a3-4) (hereinafter referred to as the formula number depending on the case). Accordingly, it is referred to as “structural unit (a3-1)” or the like)). Resin (A1) may have only 1 type in these, and may have 2 or more types.

[In the formula (a3-1),
L ^a4 represents an oxygen atom or a group represented by * —O— (CH ₂ ) _k4 —CO—O— (k4 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
p1 represents an integer of 0 to 5.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when p1 is 2 or more, the plurality of R ^a21 may be the same.
In formula (a3-2),
L ^a5 represents an oxygen atom or a group represented by * —O— (CH ₂ ) _k4 —CO—O— (k4 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
q1 represents an integer of 0 to 3.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when q1 is 2 or more, a plurality of R ^a22 may be the same.
In formula (a3-3),
L ^a6 represents an oxygen atom or a group represented by * —O— (CH ₂ ) _k4 —CO—O— (k4 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
r1 represents an integer of 0 to 3.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when r1 is 2 or more, a plurality of R ^a23 may be the same.
In formula (a3-4),
L ^a7 is an oxygen atom, * —O— (CH ₂ ) _k4 —O—, * —O— (CH ₂ ) _k4 —CO—O—, * —O— (CH ₂ ) _k4 —CO—O— ( CH _{2) k5} -CO-O- or _{* -O- (CH 2) k4 -O} -CO- (CH 2) k5 -O- (k4 and k5 independently represents an integer of 1-7. ) Represents a group represented by * Represents a bond with a carbonyl group.
R ^a24 represents a hydrogen atom or a methyl group. ]

In formula (a3-1) to formula (a3-4), L ^{a4 to} L ^a7 are the same as those described for L ^a3 in formula (a2-1).
L ^{a4 to} L ^a7 are each independently an oxygen atom or a group represented by * —O— (CH ₂ ) _k4 —CO—O—, wherein k4 is an integer of 1 to 4, preferably an oxygen atom and * —O—CH ₂ —CO—O— is more preferable, and an oxygen atom is more preferable.
R ^{a18 to} R ^a21 and R ^a24 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are preferably integers of 0 to 2, more preferably 0 or 1. When p1 is 2, two R ^a21 may be the same as or different from each other. When q1 is 2, two R ^a22 may be the same as or different from each other, and r1 is 2. Two R ^a23 may be the same or different from each other.

Preferred examples of the structural unit (a3-1) are represented by the formula (a3-1-1), the formula (a3-1-2), the formula (a3-1-3), and the formula (a3-1-4), respectively. It is what is done.

Preferred examples of the structural unit (a3-2) are represented by the formula (a3-2-1), the formula (a3-2-2), the formula (a3-2-3), and the formula (a3-2-4), respectively. It is what is done.

Preferred examples of the structural unit (a3-3) are represented by the formula (a3-3-1), the formula (a3-3-2), the formula (a3-3-3), and the formula (a3-3-4), respectively. It is what is done.

Preferred examples of the structural unit (a3-4) include the formula (a3-4-1), the formula (a3-4-2), the formula (a3-4-3), the formula (a3-4-4), the formula ( a3-4-5) and the formula (a3-4-6).

In the above compound, a compound in which the methyl group corresponding to R ^a24 is replaced with a hydrogen atom can also be mentioned as a preferred example of the structural unit (a3-4).

  Among structural units (a3), formula (a3-1-1), formula (a3-1-2), formula (a3-2-3), formula (a3-2-4), formula (a3-4-) 1) or a structural unit represented by formula (a3-4-2) is more preferred, represented by formula (a3-1-1), formula (a3-2-3) or formula (a3-4-2). More preferred are structural units.

  The structural unit (a3-1), the structural unit (a3-2), and the structural unit (a3-3) can be derived from the monomer (s) described in JP 2010-204646 A.

式（ａ３−４ｍ）で表されるモノマーの中でも、Ｌ^a７が＊−Ｏ−ＣＨ_２−ＣＯ−Ｏ−（＊は−ＣＯ−との結合手を表す。）であるモノマー、すなわち式（ａ３−４−２ｍ）で表されるモノマーは、式（ａ３−４−２ｍ−ａ）で表される化合物と、式（ａ３−４−２ｍ−ｂ）で表される化合物とを溶剤中で反応させることにより製造できる。反応に用いられる溶剤としては、塩化メチレン、テトラヒドロフラン及びアセトニトリル等が挙げられる。

The structural unit (a3-4) can be derived from the monomer (s) described in JP2012-41274A. Moreover, it can derive with the monomer represented by a formula (a3-4m).

Among the monomers represented by the formula (a3-4m), L ^a7 is _{* -O-CH 2 -CO-O} - monomer (. * Is representative of a bond to -CO-) is, i.e. the formula (a3 The monomer represented by -4-2m) reacts the compound represented by the formula (a3-4-2m-a) with the compound represented by the formula (a3-4-2m-b) in a solvent. Can be manufactured. Examples of the solvent used for the reaction include methylene chloride, tetrahydrofuran and acetonitrile.

この反応は、塩化メチレン、テトラヒドロフラン及びアセトニトリル等の溶媒の存在下で行うことが好ましい。また、この反応には、ジシクロヘキシルカルボジイミド等の縮合剤を用いてもよい。 The compound represented by the formula (a3-4-2m-a) includes a compound represented by the formula (a3-4-2m-c), a compound represented by the formula (a3-4-2m-d), and Can be made to react.

This reaction is preferably carried out in the presence of a solvent such as methylene chloride, tetrahydrofuran and acetonitrile. In this reaction, a condensing agent such as dicyclohexylcarbodiimide may be used.

式（ａ３−４−２ｍ−ｃ）で表される化合物として、所望する式（ａ３−４ｍ）で表されるモノマーに対応したＬ^a７及びＲ^a2４を有する化合物を用いれば、目的とする式（ａ３−４ｍ）で表されるモノマーを得ることができる。 Examples of the compound represented by the formula (a3-4-2m-c) include the following compounds. This compound is readily available from the market.

If a compound having L ^a7 and R ^a24 corresponding to the monomer represented by the desired formula (a3-4m) is used as the compound represented by the formula (a3-4-2m-c), the target formula ( The monomer represented by a3-4m) can be obtained.

Examples of the monomer represented by the formula (a3-4m) include the following.

In the above compound, a compound in which a methyl group corresponding to R ^a24 is replaced with a hydrogen atom can also be mentioned as a specific example of the monomer represented by the formula (a3-4m).

  When the resin (A) has the structural unit (a3), the content is preferably 5 to 70 mol%, more preferably 10 to 65 mol%, based on all the structural units of the resin (A1). -60 mol% is more preferable.

［式（ａ４−１）中、
Ｒ^４１は、水素原子又はメチル基を表す。
ｓｓは０〜２の整数を表す。
Ａ^４０及びＡ^４１は、それぞれ独立に、炭素数１〜５の脂肪族炭化水素基を表す。
ｓｓが２のとき、複数存在するＡ^４０は、互いに同一であるか相異なる。
Ｘ^４０は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
ｓｓが２のとき、複数存在するＸ^４０は、互いに同一であるか相異なる。）
Ｒ^4２は、フッ素原子を有する炭素数１〜１８の脂肪族炭化水素基を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。］
Ａ^４０及びＡ^４１の脂肪族炭化水素基は、例えばアルカンジイル基であり、該アルカンジイル基は直鎖状であっても、分岐していてもよい。アルカンジイル基としては、メチレン基、エチレン基、プロパン−１，３−ジイル基、プロパン−１，２−ジイル基、ブタン−１，４−ジイル基、ペンタン−１，５−ジイル基、ヘキサン−１，６−ジイル基等の直鎖状アルカンジイル基；１−メチルプロパン−１，３−ジイル基、２−メチルプロパン−１，３−ジイル基、２−メチルプロパン−１，２−ジイル基、１−メチルブタン−１，４−ジイル基、２−メチルブタン−１，４−ジイル基等の分岐状アルカンジイル基が挙げられる。
Ａ^４１としては、炭素数１〜４のアルカンジイル基がより好ましく、エチレン基がさらに好ましい。 <Other structural units (s)>
The resin (A) may have a structural unit (s) other than the structural unit (a2) and the structural unit (a3). Examples of the monomer for deriving such a structural unit include a monomer represented by the formula (a4-1) (hereinafter sometimes referred to as “monomer (a4-1)”).

[In the formula (a4-1),
R ⁴¹ represents a hydrogen atom or a methyl group.
ss represents an integer of 0-2.
A ⁴⁰ and A ⁴¹ each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms.
When ss is 2, a plurality of A ⁴⁰ are the same or different from each other.
X ⁴⁰ represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
When ss is 2, a plurality of X ⁴⁰ are the same or different from each other. )
R ⁴² represents a C 1-18 aliphatic hydrocarbon group having a fluorine atom, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]
The aliphatic hydrocarbon group of A ⁴⁰ and A ⁴¹ is, for example, an alkanediyl group, and the alkanediyl group may be linear or branched. Examples of alkanediyl groups include 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- Linear alkanediyl group such as 1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group And branched alkanediyl groups such as 1-methylbutane-1,4-diyl group and 2-methylbutane-1,4-diyl group.
The A ^41, more preferably an alkanediyl group having 1 to 4 carbon atoms, an ethylene group is more preferred.

で表される基（以下「基（ａ４−ｇ１）」という場合がある）の具体例を以下に示す。各具体例において、＊は結合手を表す。なお、当該基（ａ４−ｇ１）が酸素原子及びカルボニル基をともに有する場合には、カルボニルオキシ基又はオキシカルボニル基として有していると好ましい。 In formula (a4-1), formula (a4-g1)

Specific examples of the group represented by the formula (hereinafter sometimes referred to as “group (a4-g1)”) are shown below. In each specific example, * represents a bond. In addition, when the said group (a4-g1) has both an oxygen atom and a carbonyl group, it is preferable to have as a carbonyloxy group or an oxycarbonyl group.

等が挙げられる。 As the group having an oxygen atom (a4-g1),

Etc.

等が挙げられる。 As the group having a carbonyl group (a4-g1),

Etc.

等が挙げられる。 As the group having a carbonyloxy group (a4-g1),

Etc.

等が挙げられる。 As the group having an oxycarbonyl group (a4-g1),

Etc.

R ⁴² is a group in which at least one of the hydrogen atoms contained in the aliphatic hydrocarbon group is replaced with a fluorine atom. The aliphatic hydrocarbon group may partially have a carbon-carbon unsaturated bond, but an aliphatic saturated hydrocarbon group having no carbon-carbon unsaturated bond is preferable. Examples of the aliphatic saturated hydrocarbon group include alkyl groups (straight and branched) and alicyclic hydrocarbon groups, and aliphatic hydrocarbon groups in which alkyl groups and alicyclic hydrocarbon groups are combined.

Specific examples of the aliphatic hydrocarbon group having a fluorine atom of R ⁴² include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, 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- Perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5 -Decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, perfluorocyclopentyl 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-dodecafluoro Examples include a hexyl group, a perfluorocyclohexyl group, a perfluoropentylmethyl group, and a perfluorohexyl group.

（式（ａ−ｇ２）中、
Ａ¹³は、フッ素原子を有していてもよい炭素数１〜１５の２価の脂肪族炭化水素基を表す。
Ｘ¹²は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ¹⁴は、フッ素原子を有していてもよい炭素数１〜１５の１価の脂肪族炭化水素基を表す。
但し、Ａ¹³又はＡ¹⁴の少なくともいずれかはフッ素原子を有するものであり、Ａ¹³及びＡ¹⁴の炭素数の合計は１７以下である。） Examples of the group in which the methylene group constituting the aliphatic hydrocarbon group of R ⁴² is replaced by an oxygen atom or a carbonyl group include a group represented by the formula (a-g2) (hereinafter, “group (a-g2 ) ”)).

(In the formula (a-g2),
A ¹³ represents a C 1-15 divalent aliphatic hydrocarbon group which may have a fluorine atom.
X ¹² represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁴ represents a monovalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a fluorine atom.
Provided that at least one of A ¹³ or A ¹⁴ are those having a fluorine atom, the total number of carbon atoms of A ¹³ and A ¹⁴ is 17 or less. )

When A ¹³ is a divalent aliphatic hydrocarbon group having a fluorine atom, the aliphatic hydrocarbon group is typically an alkanediyl group having a fluorine atom and a divalent alicyclic carbon having a fluorine atom. Examples thereof include a hydrogen group (preferably a cycloalkanediyl group having a fluorine atom). The alkanediyl group having a fluorine atom is one in which at least one hydrogen atom contained in the alkanediyl group is substituted with a fluorine atom, and the divalent alicyclic hydrocarbon group having a fluorine atom is a divalent alicyclic group. At least one hydrogen atom contained in the alicyclic hydrocarbon group is substituted with a fluorine atom.

In the group (a-g2), both A ¹³ and A ¹⁴ may have a fluorine atom, but A ¹³ is an aliphatic hydrocarbon group having a fluorine atom, or A ¹⁴ is a fatty acid having a fluorine atom. A group hydrocarbon group is preferred. Furthermore, A ¹³ is preferably an aliphatic hydrocarbon group having a fluorine atom, and among them, A ¹³ is more preferably an alkanediyl group having a fluorine atom, and further preferably a perfluoroalkanediyl group. . The “perfluoroalkanediyl group” refers to an alkanediyl group in which all hydrogen atoms are substituted with fluorine atoms.

The number of carbon atoms of A ¹³ and A ¹⁴ is their sum is arbitrarily selected in the range of 17 or less, the number of carbon atoms of A ¹³ are members preferably 1-6, 1-3 is more preferable. On the other hand, the number of carbon atoms of A ¹⁴ is preferably 4 to 15, 5 to 12 is more preferable. Further preferred A ¹⁴ is an alicyclic hydrocarbon group having 6 to 12 carbon atoms, and a cyclohexyl group and an adamantyl group are even more preferred.

The aliphatic hydrocarbon group having a fluorine atom of R ⁴² is a perfluoroalkyl group (for example, perfluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group and perfluorooctyl group). Group) or a perfluorocycloalkyl group.

R ⁴² is more preferably a perfluoroalkyl group. More preferably, it is a C1-C6 perfluoroalkyl group, Most preferably, it is a C1-C3 perfluoroalkyl group.

Specific examples of the monomer (a4-1) include compounds represented by any of the formulas (a4-1-1) to (a4-1-22).

［式（ａ４−１’）中の符号はいずれも、前記と同義である。］ The monomer (a4-1) in which R ⁴² is a group represented by the formula (a-g2) is a monomer represented by the following formula (a4-1 ′) (hereinafter, “monomer (a4-1)” ')')).

[All the symbols in formula (a4-1 ′) have the same meanings as described above. ]

Examples of the monomer (a4-1 ′) include monomers represented by any one of the formulas (a4-1′-1) to (a4-1′-46).

In the group (a-g2), A ¹³ is preferably an aliphatic hydrocarbon group having a fluorine atom, and A ¹⁴ is preferably a cyclohexyl group or an adamantyl group. Examples of such a group (a-g2) are shown below.

このような基（ａ−ｇ２）を有するモノマー（ａ４−１’）は、上述した具体例の中では、式（ａ４−１’−７）〜式（ａ４−１’−４２）で表されるものが該当する。

The monomer (a4-1 ′) having such a group (a-g2) is represented by the formula (a4-1′-7) to the formula (a4-1′-42) in the specific examples described above. Is applicable.

  When the resin (A) has a structural unit derived from the monomer (a4-1), the content is preferably from 1 to 20 mol%, more preferably from 2 to 15 mol%, based on all structural units of the resin (A). Is more preferable, and 3 to 10 mol% is more preferable.

<Method for producing resin (A)>
The resin (A) is preferably a copolymer of the monomer (a1) and the monomer (s), more preferably the structural unit (a1-1) and / or the structural unit (a1-2). The monomer to be derived is copolymerized with the monomer that derives the structural unit (a2) and / or the structural unit (a3). Moreover, a monomer (a4-1) can also be used as a monomer (s) as needed. For example, when the resist composition is used for KrF exposure, EB exposure, or EUV exposure, a monomer that induces the structural unit (a1-1) and / or the structural unit (a1-2), and the structural unit The thing which copolymerized the monomer which induces (a2-0) can be mentioned.
The resin (A) more preferably has the structural unit (a1-1) as the structural unit (a1).
The resin (A) can be produced by subjecting the monomer as described above to a known polymerization method (for example, radical polymerization method) and polymerizing (copolymerizing) it.

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

  As for the content rate of resin (A) in this resist composition, 80 to 99 mass% is preferable with respect to solid content. Here, the “solid content” means the total of components obtained by removing the solvent (D) from the resist composition. The solid content and the content ratio of each component relative to the solid content can be obtained from the resist composition by known analysis means such as gas chromatography or liquid chromatography.

<Resin other than resin (A)>
The resist composition may contain a resin other than the resin (A).
The resin other than the resin (A) is not particularly limited as long as it does not have an acid labile group, and examples thereof include resins composed of structural units derived from known monomers used in the field. Among them, preferred is a resin having a fluorine atom in the molecule, and more preferred is a resin having a structural unit derived from the monomer (s) having a fluorine atom, and a structural unit derived from the monomer (a4-1). More preferred is a resin having In the resin having a structural unit derived from the monomer (a4-1), the content ratio of the structural unit derived from the monomer (a4-1) is preferably 70 to 100 mol% with respect to all the structural units of the resin. 80-100 mol% is more preferable, and 90-100 mol% is further more preferable.
When the resist composition contains a resin other than the resin (A), the content is preferably about 0.1 to 10% by mass, more preferably about 0.3 to 5% by mass with respect to the solid content. More preferably, about 0.5 to 3% by mass.

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

[In the formula (II),
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m ′ and n ′ each independently represents an integer of 0 to 4, and when m ′ is 2 or more, a plurality of R ^D1s may be the same or different from each other, and when n ′ is 2 or more, a plurality of R ^D2 may be the same or different from each other]

^Examples of R ^D1 and R ^D2 in formula (II) include the same groups as those described for R ¹ and R ² in formula (I). The halogen atom is preferably a fluorine atom, a chlorine atom or a bromine atom.
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an acyl group having 2 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, or a carbon number It is preferably 2 to 5 alkoxycarbonyl group, nitro group or halogen atom.
m ′ and n ′ are each independently preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and still more preferably 0.

Specific examples of compound (II) are shown below. Among these, the compounds represented by formula (II1) to formula (II3) are preferable, and the compound represented by formula (II1) is more preferable in terms of easy availability.

  As the compound (II), a commercially available product may be used, or a product produced by a known production method may be used.

  When this resist composition contains compound (II), the content is preferably 0.01 to 12 parts by mass, more preferably 0.03 to 10 parts by mass with respect to 100 parts by mass of the resin (A). 0.06 to 6 parts by mass is more preferable. In addition, the content ratio of the compound (II) is preferably about 0.01 to 10% by mass, more preferably about 0.03 to 8% by mass, and further preferably 0.05 to about the solid content. About 5% by mass.

<Basic compound (C)>
The basic compound (C) optionally contained in the resist composition is a so-called quencher in the art. 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. Preferred examples of the basic compound (C) include compounds represented by the formulas (C1) to (C8) and the formula (C1-1), and more preferably the formula (C1-1). Compounds.

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

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

［式（Ｃ１−１）中、
Ｒ^c2及びＲ^c3は、前記と同義である。
Ｒ^c4は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4は、互いに同一でも異なってもよい。］

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

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、
Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同義である。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は、互いに同一でも異なってもよい。］

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

［式（Ｃ５）及び式（Ｃ６）中、
Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、それぞれ独立に、Ｒ^c1と同義である。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同義である「。
ｏ３及びｐ３は、それぞれ独立に０〜３の整数を表し、ｏ３が２以上であるとき、複数のＲ^c14は互いに同一でも異なってもよい。ｐ３が２以上であるとき、複数のＲ^c15は互いに同一でも異なってもよい。
Ｌ^c1は、炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

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

［式（Ｃ７）及び式（Ｃ８）中、
Ｒ^c18、Ｒ^c19及びＲ^c20は、それぞれ独立に、Ｒ^c4と同義である。
ｑ３、ｒ３及びｓ３は、それぞれ独立に０〜３の整数を表し、ｑ３が２以上であるとき、複数のＲ^c18は互いに同一でも異なってもよい。ｒ３が２以上であるとき、複数のＲ^c19は互いに同一でも異なってもよい。ｓ３が２以上であるとき、複数のＲ^c20は互いに同一でも異なってもよい。
Ｌ^c2は、単結合又は炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

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

In formula (C1) to formula (C8) and formula (C1-1), the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, alkoxy group and alkanediyl group are the same as those described above. Is mentioned.
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, and 4,4′-diamino-3,3′-diethyldiphenylmethane. A Ropiruanirin, more preferably 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.

  When the basic composition (C) in the resist composition is contained, the content thereof is preferably about 0.01 to 5% by mass, more preferably 0.01 to 3% by mass with respect to the solid content. %, More preferably about 0.01 to 1% by mass.

<Solvent (D)>
When the present resist composition contains a solvent (D), the solvent (D) depends on the type and amount of the acid generator (I), resin (A), etc. An optimal one can be appropriately selected from the viewpoint that the coating property when the resist composition is applied on the substrate is improved.

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

  When the resist composition contains the solvent (D), the content is preferably 90% by mass or more, more preferably 92% by mass or more, and still more preferably 94% by mass with respect to the total amount of the resist composition. It is above, Preferably it is 99.9 mass% or less, More preferably, it is 99 mass% or less.

<Other ingredients>
The resist composition may contain components other than the above-described components (hereinafter, sometimes referred to as “component (F)”). Examples of the component (F) include additives widely used in this technical field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes.
When this resist composition contains a component (F), the content can determine suitable content according to the kind of component (F) to be used.

<Preparation method of the present resist composition>
The resist composition comprises an acid generator (I) and a resin, and a solvent (D), an acid generator (B), a compound (II), a basic compound (C) and other components used as necessary. It can be prepared by mixing (F). In such mixing, 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 solubility etc. with respect to solvent (D), such as resin (A) grades. 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.
Thus, after mixing each component, it is preferable to filter etc. using a filter with the hole diameter of about 0.003-0.2 micrometer.

<Method for producing resist pattern>
Specifically showing a method for producing a resist pattern using the present resist composition,
(1) a step of applying the resist composition on a substrate;
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
Can be mentioned. Hereinafter, each of the steps shown here is referred to as “step (1)” to “step (5)”.

Application of the resist composition on the substrate in the step (1) can be performed by a coating apparatus widely used in the resist field, such as a spin coater.
The substrate is not particularly limited, and examples thereof include substrates usually used for manufacturing semiconductor elements, such as inorganic substrates such as silicon, SiN, SiO ₂ and SiN, and coated inorganic substrates such as SOG. These substrates may be cleaned, or may be those in which an antireflection film or the like is formed on an inorganic substrate. The antireflection film can be formed from, for example, a commercially available composition for organic antireflection films.

In step (2), for example, the resist applied on the substrate by a heating means (so-called pre-bake) using a heating device such as a hot plate, a decompression means using a decompression device, or a combination of these means. The composition layer is formed by drying the composition and removing the solvent. The conditions for the heating means and the decompression means can be selected according to the type of the solvent (D) contained in the resist composition.
For example, in the case of a heating means, the drying temperature is preferably 50 to 200 ° C, more preferably 60 to 150 ° C. In the case of the decompression means, after the substrate coated with the present resist composition is sealed in a decompression dryer, the internal pressure of the decompression dryer may be about 1 to 1.0 × 10 ⁵ Pa. .
The film thickness of the composition layer thus formed is, for example, 20 to 1000 nm, and preferably 50 to 400 nm. The film thickness can be adjusted by variously adjusting the conditions of the coating apparatus.

Step (3) is a step of exposing the composition layer, and preferably the composition layer is exposed using an exposure machine. The exposure is performed through a mask (photomask) on which a desired pattern is formed. As an exposure light source of the exposure machine, an apparatus that emits ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), electron beam, ultra-ultraviolet Various types, such as those that irradiate light (EUV) and those that emit laser light from a far ultraviolet region or vacuum ultraviolet region by converting the wavelength of laser light from a solid-state laser light source (such as YAG or semiconductor laser) Can be used. When an electron beam is used as the exposure light source, the composition layer may be directly irradiated with an electron beam without using a mask. In the following description, the description will focus on the exposure step of exposing the composition layer through a mask.
When exposed through a mask, an acid is generated from the acid generator (B) contained in the composition layer in the composition layer of the exposed portion, and this acid acts to cause acid labile groups of the resin (A). A hydrophilic group is formed.

The exposure light source used in the production method of the present invention is preferably an ArF excimer laser, and more preferably immersion exposure using an ArF excimer laser as an exposure source and an immersion medium.
The exposure is preferably performed by a method in which the immersion medium is placed on the composition layer, so-called immersion exposure. When performing immersion exposure, you may perform the process of wash | cleaning the surface of the composition layer before exposure and / or after exposure with an aqueous chemical | medical solution.
The immersion medium used for the immersion exposure is transparent to the exposure wavelength of the ArF excimer laser, and can have a temperature coefficient of refractive index so as to minimize distortion of the optical image projected onto the composition layer. A liquid that is as small as possible is preferable, and water, particularly ultrapure water, is preferable because it is easily available and easy to handle. When water is used as the immersion medium, an additive that decreases the surface tension of the water and increases the surface activity may be added to the water in a small proportion. This additive is preferably one that does not dissolve the composition layer and can ignore the influence on the optical coating on the lower surface of the lens element.
The exposure amount can be appropriately set according to the resist composition to be used, the type of resist pattern to be produced, and the type of exposure light source, and is preferably 5 to 50 mJ / cm ² .
Step (3) may be repeated a plurality of times. The exposure light source and the exposure method when performing multiple exposures may be the same or different.

The heating in the step (4) includes a heating means using a heating device such as a hot plate. The heating temperature is preferably 50 to 200 ° C, more preferably 70 to 150 ° C. The heating time is preferably 10 to 180 seconds, more preferably 30 to 120 seconds.
The reaction of the acid labile group is promoted by the step (4).

In step (5), development is preferably performed using a developing device.
As a developing method, a method of immersing the composition layer subjected to the step (4) in a tank filled with the developer together with the substrate for a certain period of time (dip method), a composition layer performing the step (4) In addition, a method of developing by developing the developer by surface tension and standing still for a certain time (paddle method), a method of spraying the developer on the surface of the composition layer subjected to step (4) (spray method), Examples include a method (dynamic dispensing method) in which the substrate having the composition layer subjected to step (4) is rotated at a constant speed, and the developer is continuously applied while scanning the application nozzle at a constant speed. .
The development temperature is preferably 5 to 60 ° C., and the development time is preferably 5 to 300 seconds, more preferably 5 to 90 seconds. When developing with the dynamic dispensing method, the developing time is particularly preferably 5 to 20 seconds, and when developing with the paddle method, the developing time is particularly preferably 20 to 60 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.
A paddle method is preferable as a developing method in producing a positive resist 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. As these developing solutions, those commercially available as solvents may be used as they are.
The organic developer may contain a surfactant. The surfactant is not particularly limited, and may be, for example, an ionic surfactant or a nonionic surfactant, and may be a fluorine-based surfactant or a silicon-based surfactant.
The organic developer may contain a trace amount of water.

  The dynamic dispensing method is preferable as the developing method for producing a negative resist pattern.

After the development time has elapsed, the development may be stopped while replacing the developer in contact with the composition layer with a solvent of a different type from the developer. In addition, in order to remove the developer remaining on the resist pattern, it is preferable to wash the developed resist pattern using a rinse solution. The rinsing liquid is not particularly limited as long as it does not dissolve the produced resist pattern, and a general organic solvent can be used, but an alcohol solvent or an ester solvent is preferably used.
After the cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the resist pattern.

<Application>
This resist composition is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) irradiation, or a resist composition for EUV exposure, particularly immersion exposure. It is suitable as a resist composition for use in semiconductors and is useful for fine processing of semiconductors. In addition, since the resist composition can produce a resist pattern having excellent pattern collapse resistance, it is useful for producing a negative resist pattern using an organic developer.

Hereinafter, the present invention will be described in detail by way of examples.
In Examples and Comparative Examples, “%” and “part” representing the content and the amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value obtained by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

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

式（Ｉ１０−ａ）で表される塩３．２４部、式（Ｉ１０−ｂ）で表される化合物２．００部及びプロピレングリコールモノメチルエーテルアセテート１０．００部を仕込み、２３℃で３０分間攪拌することにより、式（Ｉ−１０）で表される塩を含む溶液を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３２５．０
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ １９９．０ Synthesis Example 1 [Synthesis of salt represented by formula (I-10)]

3.24 parts of a salt represented by the formula (I10-a), 2.00 parts of a compound represented by the formula (I10-b) and 10.00 parts of propylene glycol monomethyl ether acetate are charged and stirred at 23 ° C. for 30 minutes. As a result, a solution containing the salt represented by the formula (I-10) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 325.0
MASS (ESI (-) Spectrum): M ^- 199.0

式（Ｉ２−ａ）で表される塩３．２４部、式（Ｉ２−ｂ）で表される化合物３．４０部及びプロピレングリコールモノメチルエーテルアセテート１０部を仕込み、２３℃で３０分間攪拌することにより、式（Ｉ−２）で表される塩を含む溶液を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３２５．０
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１ Synthesis Example 2 [Synthesis of salt represented by formula (I-2)]

Charge 3.24 parts of the salt represented by the formula (I2-a), 3.40 parts of the compound represented by the formula (I2-b) and 10 parts of propylene glycol monomethyl ether acetate, and stir at 23 ° C. for 30 minutes. Thus, a solution containing the salt represented by the formula (I-2) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 325.0
MASS (ESI (−) Spectrum): M ^- 339.1

式（Ｉ３−ａ）で表される塩３．２４部、式（Ｉ３−ｂ）で表される化合物３．２４部及びプロピレングリコールモノメチルエーテルアセテート１０部を仕込み、２３℃で３０分間攪拌することにより、式（Ｉ−３）で表される塩を含む溶液を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３２５．０
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３２３．０ Synthesis Example 3 [Synthesis of salt represented by formula (I-3)]

Charge 3.24 parts of the salt represented by the formula (I3-a), 3.24 parts of the compound represented by the formula (I3-b) and 10 parts of propylene glycol monomethyl ether acetate, and stir at 23 ° C. for 30 minutes. Thus, a solution containing the salt represented by the formula (I-3) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 325.0
MASS (ESI (-) Spectrum): M ^- 323.0

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部を添加攪拌した後、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部を添加攪拌後、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分間攪拌した後、上澄み液を除去した後、濃縮した。得られた残渣に、ｎ−ヘプタン２００部を添加、２３℃で３０分間攪拌した後、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 4 [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, 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 then 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 then filtered to obtain 61.54 parts of a salt represented by the formula (B1-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ^- 339.1

式（Ｂ１−１９−ａ）で表される塩１１．２６部、式（Ｂ１−１９−ｂ）で表される化合物１０．００部、クロロホルム５０部及びイオン交換水２５部を仕込み、２３℃で１５時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、更に、該クロロホルム層にイオン交換水１５部を添加し、水洗した。この操作を５回繰り返した。クロロホルム層を濃縮し、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて２３℃で３０分間攪拌した後、ろ過することにより、式（Ｂ１−１９−ｃ）で表される塩１１．７５部を得た。 Synthesis Example 5 [Synthesis of salt represented by formula (B1-19)]

11.26 parts of a salt represented by the formula (B1-19-a), 10.00 parts of a compound represented by the formula (B1-19-b), 50 parts of chloroform and 25 parts of ion-exchanged water were charged at 23 ° C. For 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the resulting residue, the mixture was stirred at 23 ° C. for 30 minutes, and then filtered to obtain the salt 11 represented by the formula (B1-19-c). .75 parts were obtained.

式（Ｂ１−１９−ｃ）で表される塩１１．７１部、式（Ｂ１−１９−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（Ｂ１−１９）で表される塩６．８４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２３７．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３２３．０

11.71 parts of a salt represented by the formula (B1-19-c), 1.70 parts of a compound represented by the formula (B1-19-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 obtained residue, stirred, and then filtered to obtain 6.84 parts of the salt represented by the formula (B1-19). Got.
MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 323.0

式（ａ４−１−７ｍ−２）で表される化合物８８．００部、メチルイソブチルケトン６１６．００部及びピリジン６０．９８部を、２３℃で３０分間攪拌混合し、０℃まで冷却した。同温度を保持したまま、得られた混合物に、式（ａ４−１−７ｍ−１）で表される化合物１９９．１７部を、１時間かけて添加した後、更に、１０℃程度まで温度を上げ、同温度で１時間攪拌した。得られた反応混合物に、ｎ−へプタン１４４６．２２部及び２％塩酸水溶液７０３．４１部を加え、２３℃で３０分間攪拌した。静置、分液することにより回収された有機層に、２％塩酸水溶液３３７．６４部を仕込み、２３℃で３０分間攪拌した。静置、分液することにより有機層を回収した。回収された有機層に、イオン交換水３６１．５６部を仕込み２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。回収された有機層に、１０％炭酸カリウム水溶液４４３．９２部を仕込み、２３℃で３０分間攪拌し、静置、分液することにより有機層を洗浄した。このような洗浄操作を２回繰り返した。回収された有機層に、イオン交換水３６１．５６部を仕込み、２３℃で３０分間攪拌、静置した後、分液することにより有機層を水洗した。このような水洗操作を５回繰り返した。回収された有機層を濃縮し、式（ａ４−１−７ｍ）で表される化合物１６３．６５部を得た。
ＭＳ（質量分析）：２７６．０（分子イオンピーク） Synthesis Example 6 [Synthesis of Monomer (a4-1-7m)]

88.00 parts of the compound represented by the formula (a4-1-7m-2), 616.000 parts of methyl isobutyl ketone and 60.98 parts of pyridine were stirred and mixed at 23 ° C. for 30 minutes and cooled to 0 ° C. While maintaining the same temperature, 199.17 parts of the compound represented by the formula (a4-1-7m-1) was added to the obtained mixture over 1 hour, and the temperature was further increased to about 10 ° C. And stirred at the same temperature for 1 hour. To the obtained reaction mixture, 1446.22 parts of n-heptane and 703.41 parts of 2% aqueous hydrochloric acid were added, and the mixture was stirred at 23 ° C. for 30 minutes. The organic layer recovered by standing and liquid separation was charged with 337.64 parts of 2% aqueous hydrochloric acid and stirred at 23 ° C. for 30 minutes. The organic layer was recovered by standing and liquid separation. To the recovered organic layer, 361.56 parts of ion-exchanged water was charged, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. The recovered organic layer was charged with 443.92 parts of a 10% aqueous potassium carbonate solution, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer. Such washing operation was repeated twice. 361.56 parts of ion-exchanged water was added to the collected organic layer, stirred and left at 23 ° C. for 30 minutes, and then separated to wash the organic layer with water. Such washing operation was repeated 5 times. The collected organic layer was concentrated to obtain 163.65 parts of a compound represented by the formula (a4-1-7m).
MS (mass spectrometry): 276.0 (molecular ion peak)

式（ａ４−１−１１ｍ−２）で表される化合物１０．００部、テトラヒドロフラン４０．００部及びピリジン７．２９部を、２３℃で３０分間攪拌混合し、０℃まで冷却した。同温度を保持したまま、得られた混合物に、式（ａ４−１−１１ｍ−１）で表される化合物３３．０８部を、１時間かけて添加し、さらに、２３℃程度まで温度を上げ、同温度で３時間攪拌した。得られた反応物に、酢酸エチル３６１．５１部及び５％塩酸水溶液２０．１９部を加え、２３℃で３０分間攪拌した。攪拌・静置し、分液することにより回収された有機層に、飽和炭酸水素ナトリウム水溶液８１．４２部を仕込み、２３℃で３０分間攪拌し、静置した。その後、これを分液することにより有機層を回収した。回収された有機層に、イオン交換水９０．３８部を仕込み２３℃で３０分間攪拌、静置し、分液することにより有機層を水洗した。このような水洗操作を５回繰り返した。回収された有機層を濃縮し、式（ａ４−１−１１ｍ）で表される化合物２３．４０部を得た。
質量スペクトル：３２６．０（分子ピーク） Synthesis Example 7 [Synthesis of Monomer (a4-1-11m)]

10.00 parts of the compound represented by the formula (a4-1-11m-2), 40.00 parts of tetrahydrofuran and 7.29 parts of pyridine were stirred and mixed at 23 ° C. for 30 minutes and cooled to 0 ° C. While maintaining the same temperature, 33.08 parts of the compound represented by the formula (a4-1-11m-1) was added to the obtained mixture over 1 hour, and the temperature was further increased to about 23 ° C. The mixture was stirred at the same temperature for 3 hours. To the obtained reaction product, 361.51 parts of ethyl acetate and 20.19 parts of 5% aqueous hydrochloric acid solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. The organic layer recovered by stirring and standing and separating was charged with 81.42 parts of a saturated aqueous sodium hydrogen carbonate solution, stirred at 23 ° C. for 30 minutes, and allowed to stand. Then, the organic layer was collect | recovered by liquid-separating this. The collected organic layer was charged with 90.38 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such washing operation was repeated 5 times. The collected organic layer was concentrated to obtain 23.40 parts of a compound represented by the formula (a4-1-11m).
Mass spectrum: 326.0 (molecular peak)

式（ａ３−４−２ｍ−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（ａ３−４−２ｍ’−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（ａ３−４−２ｍ−３）で表される化合物４４．２８部を得た。 Synthesis Example 8 (Synthesis of monomer (a3-4-2m))

33.48 parts of the compound represented by the formula (a3-4-2m-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 (a3-4-2m′-2) was added, and the mixture was stirred for 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 (a3-4-2m-3).

前記のようにして得られた式（ａ３−４−２ｍ−３）で表される化合物１９．４２部、式（ａ３−４−２ｍ−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（ａ３−４−２ｍ）で表される化合物１２．８９部を得た。
ＭＡＳＳ（質量分析）：３０８．１（分子イオンピーク）

19.42 parts of the compound represented by the formula (a3-4-2m-3) obtained as described above, 18.22 parts of the compound represented by the formula (a3-4-2m-4) and 200 acetonitrile. Parts were charged to the reactor and mixed. 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. 12.89 parts of the compound represented by the formula (a3-4-2m) is obtained by subjecting the concentrate to column fractionation (column fractionation conditions, stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., Ltd., developing solvent: ethyl acetate). Got.
MASS (mass spectrometry): 308.1 (molecular ion peak)

以下、これらのモノマーをその式番号に応じて、「モノマー（ａ１−１−３ｍ）」等という。 Synthesis of Resin (A) Monomers used for the synthesis of resin (A) are shown below.

Hereinafter, these monomers are referred to as “monomer (a1-1-3m)” or the like according to the formula number.

Synthesis Example 8 [Synthesis of Resin X1]
As the monomer, monomer (a4-1-11m) and monomer (a1-1-3m) were used, and the molar ratio [monomer (a4-1-11m): monomer (a1-1-3m)] was 40:60. Then, methyl isobutyl ketone 1.2 mass times the total monomer amount was added to make a solution. To this solution, 3 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added with respect to the total monomer amount, and heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 9/1 mixing solution to precipitate the resin, and this resin was filtered to obtain a resin X1 having a weight average molecular weight of 7.9 × 10 ³ (co-polymer). Polymer) with a yield of 57%. This resin X1 has the following structural units.

Synthesis Example 9 [Synthesis of Resin X2]
The monomer (a4-1-7m) was used as a monomer, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the solution in an amount of 0.7 mol% and 2.1 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The 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 to perform the reprecipitation operation twice. 8 × 10 ⁴ resin X2 was obtained with a yield of 77%. This resin X2 has the following structural units.

Synthesis Example 10 [Synthesis of Resin A1]
As the monomer, using monomer (a1-1-3m), monomer (a1-2-9m), monomer (a2-1-3m), monomer (a3-2-3m) and monomer (a3-1-1m), The molar ratio [monomer (a1-1-3m): monomer (a1-2-9m): monomer (a2-1-3m): monomer (a3-2-3m): monomer (a3-1-1m)] It mixed so that it might become 45: 14: 2.5: 22: 16.5, and 1.5 mass times propylene glycol monomethyl ether acetate of the total monomer amount was added, and it was set as the solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.95 mol% and 2.85 mol%, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 4/1 mixing solution to precipitate the resin, and the resin was filtered to obtain a resin A1 having a weight average molecular weight of 7.8 × 10 ³ (co-polymer). Polymer) with a yield of 73%. This resin A1 has the following structural units. Resin A1 corresponds to the resin (A) and was soluble in 2-heptanone.

Synthesis Example 11 [Synthesis of Resin A2]
As the monomer, monomer (a1-1-1m), monomer (a3-1-1m) and monomer (a2-1-1m) were used, and the molar ratio [monomer (a1-1-1m): monomer (a3-1) −1 m): monomer (a2-1-1m)] was 35:45:20, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.0 mol% and 3.0 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and this resin was filtered to obtain a resin A2 (copolymer) having a weight average molecular weight of 7.0 × 10 ³ with a yield of 75%. Got in. This resin A2 has the following structural units. Resin A2 corresponds to the resin (A) and was soluble in 2-heptanone.

Synthesis Example 12 [Synthesis of Resin A3]
As the monomer, using monomer (a1-1-2m), monomer (a1-2-3m), monomer (a2-1-1m), monomer (a3-1-1m) and monomer (a3-4-2m), The molar ratio [monomer (a1-1-2m): monomer (a1-2-3m): monomer (a2-1-1m): monomer (a3-1-1m): monomer (a3-4-2m)] It mixed so that it might be set to 32: 7: 8: 43: 10, and 1.5 mass times dioxane of 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 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 A3 (copolymer) was obtained with a yield of 80%. This resin A3 has the following structural units. Resin A3 corresponds to the resin (A) and was soluble in 2-heptanone.

Synthesis Example 13 [Synthesis of Resin A4]
As the monomer, the monomer (a1-1-3m), the monomer (a1-2-9m), the monomer (a2-1-3m), the monomer (a3-2-3m) and the monomer (a3-4-2m) are used. The molar ratio [monomer (a1-1-3m): monomer (a1-2-9m): monomer (a2-1-3m): monomer (a3-2-3m): monomer (a3-4-2m)] It mixed so that it might be set to 45: 14: 2.5: 22.5: 16, and 1.5 mass times dioxane of 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, 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 A4 (copolymer) was obtained with a yield of 71%. This resin A4 has the following structural units. Resin A4 corresponds to the resin (A) and was soluble in 2-heptanone.

Synthesis Example 14 [Synthesis of Resin A5]
As the monomer, monomer (a1-1-3m), monomer (a1-2-9m), monomer (a2-1-3m), monomer (a3-2-3m), monomer (a3-1-1m) and monomer ( a3-4-2m) and its molar ratio [monomer (a1-1-3m): monomer (a1-2-9m): monomer (a2-1-3m): monomer (a3-2-3m): monomer (A3-1-1m): monomer (a3-4-2m)] is mixed at 45: 14: 2.5: 17.5: 5: 16, and 1.5 mass times the total monomer amount. 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 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 A5 (copolymer) was obtained with a yield of 69%. This resin A5 has the following structural units. Resin A5 corresponds to the resin (A) and was soluble in 2-heptanone.

Synthesis Example 15 [Synthesis of Resin A6]
As the monomer, the monomer (a1-1-3m), the monomer (a1-2-9m), the monomer (a2-1-3m) and the monomer (a3-4-2m) were used, and the molar ratio [monomer (a1-1 -3m): monomer (a1-2-9m): monomer (a2-1-3m): monomer (a3-4-2m)] is mixed at 45: 14: 2.5: 38.5, Dioxane of 1.5 mass times the total monomer amount was added to make a solution. 0.95 mol% and 2.85 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the solution, respectively, based on the total monomer amount, and these were added at 73 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / ion-exchanged water = 4/1 mixing solution to precipitate the resin, and the resin was filtered to obtain a resin A6 having a weight average molecular weight of 8.4 × 10 ³ (co-polymer). Polymer) with a yield of 67%. This resin A6 has the following structural units. Resin A6 corresponds to the resin (A) and was soluble in 2-heptanone.

Synthesis Example 16 [Synthesis of Resin X3]
As the monomer, the monomer (a4-1m) and the monomer (a1-1-1m) are used and mixed so that the molar ratio (monomer (a4-1m): monomer (a1-1-1m)) is 80:20. Then, 1.5 mass times dioxane of the total monomer amount was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.5 mol% and 1.5 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 a resin, and this resin was filtered to obtain a resin X3 (copolymer) having a weight average molecular weight of 2.8 × 10 ^{4 in} a yield of 70%. Got in. This resin X3 has the following structural units.

Examples 1-18, Comparative Example 1
<Preparation of resist composition>
As shown in Table 2, each component and a solvent (D) described later were mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

Ｂ２：国際公開第２００８／９９８６９号の実施例及び特開２０１０−２６４７８号公報記載の実施例に従って合成

Ｂ３：特開２００５−２２１７２１号公報記載の実施例に従って合成

<Acid generator (I)>
I-10: salt represented by formula (I-10) (Synthesis Example 1)
I-2: salt represented by formula (I-2) (Synthesis Example 2)
I-3: salt represented by formula (I-3) (Synthesis Example 3)
<Acid generator (B)>
B1-5: salt represented by formula (B1-5) (Synthesis Example 4)
B1-19: salt represented by formula (B1-19) (Synthesis Example 5)
B1-3: synthesized according to the example of JP 2010-152341 A

B2: synthesized according to the examples of WO2008 / 99869 and the examples described in JP2010-26478A

B3: synthesized according to examples described in JP-A-2005-221721

<Resin>
A1: Resin A1 (Synthesis Example 10)
A2: Resin A2 (Synthesis Example 11)
A3: Resin A3 (Synthesis Example 12)
A4: Resin A4 (Synthesis Example 13)
A5: Resin A5 (Synthesis Example 14)
A6: Resin A6 (Synthesis Example 15)
X1: Resin X1 (Synthesis Example 8)
X2: Resin X2 (Synthesis Example 9)
X3: Resin X3 (Synthesis Example 16)

＜塩基性化合物（Ｃ）：クエンチャー＞
Ｃ１：トリ−ｎ−ペンチルアミン <Compound (II)>
II1: Made by Tokyo Chemical Industry Co., Ltd.

<Basic compound (C): quencher>
C1: Tri-n-pentylamine

<Solvent (D)>
Propylene glycol monomethyl ether acetate 270 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 10 parts γ-butyrolactone 3.5 parts

Examples 1 to 18 and Comparative Example 1
<Manufacture of negative resist pattern and its evaluation>
An organic antireflection film composition [SiARC; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to form a film having a thickness of 185 nm on the wafer. An organic antireflection film was formed. On the obtained organic antireflection film, each of the resist compositions shown in Table 3 was spin-coated so that the film thickness after drying (prebaking) was 100 nm.
The wafer coated with the resist composition was pre-baked (PB) for 60 seconds at a temperature described in the “PB” column of Table 2 with a direct hot plate to form a composition layer. ArF excimer laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, Annular σ = 0.85 / 0.65 XY polarized light] is used for the composition layer formed on the silicon wafer. The line and space pattern (pitch 90 nm / line width 45 nm) was subjected to immersion exposure by changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking (PEB) was performed on the hot plate at the temperature described in the “PEB” column of Table 2 for 60 seconds. Then, the negative resist pattern was manufactured by developing the composition layer on the silicon wafer by using a dynamic dispensing method at 23 ° C. for 20 seconds using 2-heptanone (manufactured by Kyowa Hakko Co., Ltd.) as a developer. .
The obtained resist pattern was observed with a scanning electron microscope, and the exposure amount at which the line pattern width was 45 nm was defined as the effective sensitivity.

<Pattern collapse evaluation (PCM) evaluation>
In the obtained resist pattern, a line pattern formed with an exposure amount higher than the effective sensitivity is observed. If the line width is 40 nm or less, no pattern disappearance due to falling or peeling is observed, and the line width is 40 nm. When larger, the case where pattern disappearance due to falling or peeling was observed was taken as x. The results are shown in Table 3. The numbers in parentheses indicate the minimum line width (nm) of the resist pattern in which no pattern disappearance is observed. Here, the mask line width means the line width of the pattern transferred to the substrate by exposure, and does not mean the line width of the translucent portion of the mask.

Examples 19 to 33 and Comparative Example 2
<Manufacture of negative resist pattern>
A negative resist pattern was produced by performing the same operation as in Example 1 except that butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the developer.
In the obtained resist pattern, the exposure amount at which the line width of the line pattern was 45 nm was defined as effective sensitivity.

<Focus margin evaluation (DOF)>
A negative resist pattern was manufactured in the same manner as described above except that the exposure was performed while changing the focus stepwise in terms of effective sensitivity. In the obtained resist pattern, the focus range in which the line pattern width is 45 nm ± 5% (42.7 to 47.3 nm) was defined as DOF. The results are shown in Table 4.

Examples 34 to 48 and Comparative Example 3
A negative resist pattern was produced by performing the same operation as in Example 1, and the same evaluation as in Example 19 was performed. The results are shown in Table 5.

  From the above results, it can be seen that according to the resist composition of the present invention, a negative resist pattern having excellent pattern collapse resistance can be produced. Furthermore, it can be seen from Tables 4 and 5 that according to the resist composition of the present invention, the focus margin when producing a negative resist pattern is wide.

  If the resist composition of this invention is used, the resist pattern which has the outstanding pattern collapse tolerance can be manufactured.

Claims (8)

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

[In the formula (I),
R ¹ and R ² are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number. Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m and n each independently represent an integer of 0 to 4, and when m is 2 or more, all or a part of the plurality of R ¹ may be the same, and when n is 2 or more, a plurality of All or part of R ² may be the same.
A ⁻ represents an organic anion. ]   The resin having an acid labile group is soluble in a developer containing at least one selected from the group consisting of 2-heptanone and butyl acetate, and at least selected from the group consisting of 2-heptanone and butyl acetate by the action of an acid The resist composition according to claim 1, which is a resin that is insoluble or hardly soluble in a developer containing one kind. The resist composition according to claim 1, wherein A ^{− in the} formula (I) is an organic sulfonate anion, an organic sulfonamide anion, an organic sulfonimide anion, or an organic carboxylate anion. The resist composition according to claim 1, wherein A ⁻ in the formula (I) is an anion represented by the formula (IA).

[In the formula (IA),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group. May be.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. The methylene group constituting the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. ]   Furthermore, the resist composition in any one of Claims 1-4 containing a solvent.   Furthermore, the resist composition in any one of Claims 1-5 containing acid generators other than the acid generator represented by Formula (I). Furthermore, the resist composition in any one of Claims 1-6 containing the compound represented by Formula (II).

[In the formula (II),
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m ′ and n ′ each independently represent an integer of 0 to 4, and when m ′ is 2 or more, all or some of the plurality of R ^D1 may be the same, and n ′ is 2 or more. In this case, all or some of the plurality of R ^D2 may be the same.] (1) The process of apply | coating the resist composition in any one of Claims 1-7 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including: