JP6123383B2 - Resin, resist composition and method for producing resist pattern - Google Patents

Description

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

（式中、Ｒ¹、Ｒ^a、Ｒ^b、Ｒ^c、Ｒ^d、Ｒ^e、Ｒ^f及びＲ^gは、同一又は異なって、水素原子又はメチル基を示し、Ｘ¹、Ｘ²及びＸ³は−ＣＨ₂−又は−ＣＯ−Ｏ−を示す。Ｘ¹、Ｘ²及びＸ³のうち少なくとも１つは−ＣＯ−Ｏ−である。ｍ、ｐ及びｑはそれぞれ０〜２の整数を示す）で表されるモノマー単位から選択された少なくとも１種のモノマー単位を含むフォトレジスト用高分子化合物が記載されている。 For example, Patent Document 1 discloses the following formulas (Ia) and (Ib)

(Wherein R ¹ , R ^a , R ^b , R ^c , R ^d , R ^e , R ^f and R ^g are the same or different and represent a hydrogen atom or a methyl group, and X ¹ , X ² and X ³ Represents —CH ₂ — or —CO—O—, wherein at least one of X ¹ , X ² and X ³ is —CO—O—, and m, p and q each represents an integer of 0 to 2. The polymer compound for photoresist containing at least 1 type of monomer unit selected from the monomer unit represented by this is described.

JP 2001-240625 A

  An object of the present invention is to provide a resin that can be used as a resist composition capable of producing a resist pattern having a good cross-sectional shape.

［式（Ｉ）中、
Ｒ^１は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ａ^１は、単結合、^＊−Ａ^２−Ｏ−、^＊−Ａ^２−ＣＯ−Ｏ−、^＊−Ａ^２−ＣＯ−Ｏ−Ａ^３−ＣＯ−Ｏ−又は^＊−Ａ^２−Ｏ−ＣＯ−Ａ^３−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ａ^２及びＡ^３は、それぞれ独立に、炭素数１〜６のアルカンジイル基を表す。］

［式（II）中、
Ｒ^７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。
環Ｘ^１は、炭素数２〜３６の複素環を表し、該複素環に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１〜２４の炭化水素基、炭素数１〜１２のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基で置換されていてもよい。］
〔２〕酸の作用により分解し、有機溶剤を含む溶媒に対する溶解性が減少する特性を有する〔１〕記載の樹脂。
〔３〕 有機溶剤は酢酸ブチル又は２−ヘプタノンである〔２〕記載の樹脂。
〔４〕前記の第１構造単位、第２構造単位及び第３構造単位の含有割合（モル比）が、［第１構造単位の含有量］／［第２構造単位の含有量］／［第３構造単位の含有量］で表して、［３〜８０］／［２〜６０］／［１０〜９５］の範囲である〔１〕〜〔３〕の何れか１つに記載の樹脂。
〔５〕 前記〔１〕〜〔４〕のいずれか１つに記載の樹脂と、酸発生剤とを含有するレジスト組成物。
〔６〕前記酸発生剤が、式（Ｂ１）で表される〔５〕記載のレジスト組成物。

［式（Ｂ１）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、２価の炭素数１〜２４の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置き換わっていてもよく、前記２価の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３〜１８の脂環式炭化水素基、水素原子又はフッ素原子を表し、該脂環式炭化水素基を構成するメチレン基は、酸素原子、カルボニル基又はスルホニル基に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］
〔７〕さらに溶剤を含有する〔５〕又は〔６〕記載のレジスト組成物。
〔８〕（１）上記〔５〕〜〔７〕の何れか１つに記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層を露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程
を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A resin having a first structural unit represented by formula (I), a second structural unit represented by formula (II), and a third structural unit containing an acid labile group.

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

[In the formula (II),
R ⁷ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
Ring ^{X 1} represents a heterocycle having 2 to 36 carbon atoms, a hydrogen atom contained in the heterocyclic ring, halogen atom, hydroxy group, a hydrocarbon group having 1 to 24 carbon atoms, an alkoxy group having 1 to 12 carbon atoms , May be substituted with an acyl group having 2 to 4 carbon atoms or an acyloxy group having 2 to 4 carbon atoms. ]
[2] The resin according to [1], which is decomposed by the action of an acid and has a property of reducing solubility in a solvent containing an organic solvent.
[3] The resin according to [2], wherein the organic solvent is butyl acetate or 2-heptanone.
[4] The content ratio (molar ratio) of the first structural unit, the second structural unit, and the third structural unit is [content of first structural unit] / [content of second structural unit] / [first The resin according to any one of [1] to [3], which is represented by [Content of 3 structural units] and is in the range of [3 to 80] / [2 to 60] / [10 to 95].
[5] A resist composition containing the resin according to any one of [1] to [4] and an acid generator.
[6] The resist composition according to [5], wherein the acid generator is represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, The methylene group constituting the hydrogen group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, a hydrogen atom or a fluorine atom, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A carbonyl group or a sulfonyl group may be substituted.
Z ⁺ represents an organic cation. ]
[7] The resist composition according to [5] or [6], further containing a solvent.
[8] (1) A step of applying the resist composition according to any one of [5] 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 method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.

  According to the resist composition containing the resin of the present invention, a resist pattern having an excellent cross-sectional shape can be produced.

It is a figure which represents typically the quality of the cross-sectional shape of a resist pattern (one line and space pattern part).

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

  The present invention contains the resin of the present invention (hereinafter sometimes referred to as “resin (A)”), the resin (A) and an acid generator (hereinafter sometimes referred to as “acid generator (B)”). The resist composition (hereinafter referred to as “resin (A)” in some cases) will be described.

<Resin (A)>
The resin (A) has the first structural unit, the second structural unit, and the third structural unit. First, these structural units will be described with specific examples and suitable examples.

［式（Ｉ）中、
Ｒ^１は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ａ^１は、単結合、^＊−Ａ^２−Ｏ−、^＊−Ａ^２−ＣＯ−Ｏ−、^＊−Ａ^２−ＣＯ−Ｏ−Ａ^３−ＣＯ−Ｏ−又は^＊−Ａ^２−Ｏ−ＣＯ−Ａ^３−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ａ^２及びＡ^３は、それぞれ独立に、炭素数１〜６のアルカンジイル基を表す。］ The first structural unit is represented by the formula (I).

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

Examples of the halogen atom in R ¹ of the formula (I) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkyl group represented by R ¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. Preferably, it is a C1-C4 alkyl group, More preferably, it is a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom represented by R ¹ include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl. A group, a perfluorohexyl group, a perchloromethyl group, a perbromomethyl group, a periodiomethyl group, and the like. Among these, R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom, a methyl group, or an ethyl group.

A ¹ in formula (I) is a single bond, ^* -A ² -O-, ^* -A ² -CO-O-, ^* -A ² -CO-O-A ² -CO-O- or ^* -A. ^{2 -O-CO-a 2} -O- to represent, ^{a 2} is an alkanediyl group having 1 to 6 carbon atoms. Specific examples of the alkanediyl group include those already exemplified in the range of 1 to 6 carbon atoms.
Among the above specific examples, A ¹ is a single bond or ^* —A ² —CO—O—, and more preferably a single bond, —CH ₂ —CO—O— or —C ₂ H ₄ —CO—. O-.

Specific examples of the first structural unit are shown below.

In the first structural units represented by formula (aa-1) to formula (aa-6), structural units in which the methyl group corresponding to R ¹ is replaced with a hydrogen atom are also given as specific examples of the first structural unit. be able to.

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

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

［式（Ｉ’）中、Ｒ^１は上記と同じ基を表す。］ Compound (I ′) [compound represented by formula (I′-1)] in which A ¹ is * —CH ₂ —CO—O— (* represents a bond to —CO—O—) is The compound represented by formula (I′-1-a) can be obtained by reacting the compound represented by formula (I′-1-b) in a solvent. Here, methylene chloride, tetrahydrofuran, acetonitrile, and the like are preferably used as the solvent.

[In formula (I ′), R ¹ represents the same group as described above. ]

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

[In formula (I ′), R ¹ represents the same group as described above. ]
In this reaction, a condensation catalyst such as dicyclohexylcarbodiimide can also be used.

Examples of the compound represented by the formula (I′-1-c) include compounds represented below. The compounds represented by formula (I′-1-c) and formula (I′-1-d) are easily available from the market.

なお、式（ａａ’−１）〜式（ａａ’−６）でそれぞれ表される化合物（Ｉ’）について、Ｒ^１に相当するメチル基が水素原子に置き換わった構造単位も、化合物（Ｉ’）の具体例として挙げることができる。 In the above production method, various compounds (I ′) can be obtained by substituting the compound represented by the formula (I′-1-c) with a desired compound represented by A ¹ or R ¹ . Here, specific examples of the compound (I ′) are shown below.

In addition, for the compound (I ′) represented by each of the formulas (aa′-1) to (aa′-6), the structural unit in which the methyl group corresponding to R ¹ is replaced with a hydrogen atom is also represented by ).

  The content ratio of the first structural unit in the resin (A) is usually in the range of 1 to 80 mol% and in the range of 2 to 75 mol% with respect to all the structural units (100 mol%) of the resin (A). It is preferable that it is, it is more preferable in the range of 3-70 mol%, and it is further more preferable in the range of 5-65 mol%. However, this content ratio is preferably determined in consideration of the content ratios of the first structural unit, the second structural unit, and the third structural unit described later.

［式（ＩＩ）中、
Ｒ^７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。
環Ｘ^１は、炭素数２〜３６の複素環を表し、該複素環に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１〜２４の炭化水素基、炭素数１〜１２のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基で置換されていてもよい。］ Next, the second structural unit will be described. The second structural unit is represented by the formula (II).

[In the formula (II),
R ⁷ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
Ring ^{X 1} represents a heterocycle having 2 to 36 carbon atoms, a hydrogen atom contained in the heterocyclic ring, halogen atom, hydroxy group, a hydrocarbon group having 1 to 24 carbon atoms, an alkoxy group having 1 to 12 carbon atoms , May be substituted with an acyl group having 2 to 4 carbon atoms or an acyloxy group having 2 to 4 carbon atoms. ]

Examples of the halogen atom for R ⁷ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group represented by R ⁷ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
Examples of the alkyl group which may have a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. Group, perfluorohexyl group and the like.

R ⁷ is preferably a methyl group or a hydrogen atom.

Ring X ¹ represents a heterocyclic ring having 2 to 36 carbon atoms. The heterocyclic ring includes a carbon atom of a carbonyl group (—CO—) and a nitrogen atom as atoms constituting the ring (ring constituting atom). Is included. The heterocyclic ring may contain a hetero atom other than the nitrogen atom as a ring constituent atom. In addition, the heterocyclic ring may be an aromatic heterocyclic ring, a non-aromatic heterocyclic ring, and may be monocyclic or polycyclic.

Ring X ¹ is preferably one in which a carbonyl group and a nitrogen atom contained in the heterocyclic ring are arranged at adjacent positions (having an amide bond in the heterocyclic ring).

の形式で例示（ただし、＊はカルボニル基との結合手であり、カルボニル基を介して、樹脂主鎖と結合している。）すると、以下の基が挙げられる。 Preferred heterocyclic ring as ring X ¹ (the heterocyclic ring arranged at the position where —CO— and the nitrogen atom contained in the heterocyclic ring are adjacent to each other) is the following group contained in the formula (II):

(Wherein * is a bond to a carbonyl group and is bonded to the resin main chain via the carbonyl group), the following groups are exemplified.

芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ｐ−メチルフェニル基、ｐ−ｔｅｒｔ−ブチルフェニル基、ｐ−アダマンチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、ビフェニル基、フェナントリル基、２，６−ジエチルフェニル基、２−メチル−６−エチルフェニル等のアリール基等、好ましくは炭素数６〜１４の芳香族炭化水素基が挙げられる。
脂肪族炭化水素基と脂環式炭化水素基とを組み合わせた基としては、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。
脂肪族炭化水素基と芳香族炭化水素基とを組み合わせた基としては、ベンジル基、フェネチル基、フェニルプロピル基、ナフチルメチル基及びナフチルエチル基等のアラルキル基が挙げられる。 Examples of the hydrocarbon group in Ring X ¹ include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining these.
Examples of the aliphatic hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, and preferably an alkyl group having 1 to 4 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. A cycloalkyl group such as a group, preferably a cycloalkyl group having 3 to 6 carbon atoms. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, the following groups, and preferably an alicyclic hydrocarbon group having 10 to 18 carbon atoms.

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, and preferably aromatic hydrocarbon groups having 6 to 14 carbon atoms.
Examples of the group obtained by combining an aliphatic hydrocarbon group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
Examples of the group obtained by combining an aliphatic hydrocarbon group and an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group.

Examples of the halogen atom in the ring X ¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, and an isobutyryloxy group.

Ring X ¹ is preferably a 4- to 7-membered heterocyclic ring containing a nitrogen atom or a heterocyclic ring containing this 4- to 7-membered ring, and a 4- to 6-membered heterocyclic ring containing a nitrogen atom or this 4- to 6-membered ring Heterocycles containing rings are more preferred. Furthermore, the ring in which the carbonyl group is bonded to the nitrogen atom, that is, the ring X ¹ is preferably a lactam ring.

［式（IIＡ）中、
Ｒ²³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。
Ｒ²⁴、Ｒ²⁵、Ｒ²⁶、Ｒ²⁷、Ｒ²⁸及びＲ²⁹は、それぞれ独立に、水素原子又は炭素数１〜２４の炭化水素基を表すか、Ｒ²⁴、Ｒ²⁵、Ｒ²⁶、Ｒ²⁷、Ｒ²⁸及びＲ²⁹の中から選ばれる２つは、互いに結合して炭素数３〜３０の環を形成し、該炭化水素基及び該環に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基に置換されていてもよく、該炭化水素基及び該環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。
ｎは、０〜３の整数を表す。］ A specific example of the second structural unit is represented, for example, by the following formula (IIA).

[In the formula (IIA),
R ²³ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms, or R ²⁴ , R ²⁵ , R ²⁶ , R ^27. , R ²⁸ and R ²⁹ are bonded to each other to form a ring having 3 to 30 carbon atoms, and the hydrocarbon group and the hydrogen atom contained in the ring are a halogen atom, a hydroxy group, The hydrocarbon group and the ring may be substituted with an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms. May be replaced with an oxygen atom or a carbonyl group.
n represents an integer of 0 to 3. ]

［式（IIＢ）中、
Ｒ³¹は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
ｎ３は、０〜８の整数を表す。
Ｒ³²は、ハロゲン原子、ヒドロキシ基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基を表す。
ｎ３が２以上のとき、複数のＲ³²は互いに同一又は相異なる。］ The second structural unit represented by the formula (IIA) is preferably represented by the formula (IIB) and the formula (IIC).

[In the formula (IIB),
R ³¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
n3 represents an integer of 0 to 8.
R ³² represents a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms.
When n3 is 2 or more, the plurality of R ³² are the same or different from each other. ]

R ³¹ in formula (IIB) is preferably a hydrogen atom or a methyl group in the same manner as R ⁷ in formula (II). R ³² is preferably a fluorine atom, a hydroxy group, an acetyl group, a methyl group or an ethyl group. n3 is preferably 0 or 1, more preferably 0.

［式（IIＣ）中、
Ｒ⁴¹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。
ｎ４は、０〜１４の整数を表す。
Ｒ⁴²は、ハロゲン原子、ヒドロキシ基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基を表す。
ｎ４が２以上のとき、複数のＲ^４2は互いに同一又は相異なる。］

[In the formula (IIC),
R ⁴¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
n4 represents the integer of 0-14.
^R42 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms.
When n4 is 2 or more, the plurality of R ⁴² are the same or different from each other. ]

R ⁴¹ in formula (IIC) is preferably a hydrogen atom or a methyl group in the same manner as R ⁷ in formula (II). R ⁴² is preferably a fluorine atom, a hydroxy group, an acetyl group, a methyl group or an ethyl group. n4 is preferably 0 or 1, more preferably 0.

Examples of the second structural unit include the following structural units.

ここに示した第２構造単位の具体例において、Ｒ^７に相当するメチル基が水素原子に置き換わったものも、第２構造単位の具体例として挙げることができる。これらの中でも、式（IIＢ）で表される第２構造単位が好ましい。

In the specific examples of the second structural unit shown here, those in which the methyl group corresponding to R ⁷ is replaced with a hydrogen atom can also be given as specific examples of the second structural unit. Among these, the second structural unit represented by the formula (IIB) is preferable.

［式（II’）中の符号はいずれも、上記と同じ意味を表す。］ The second structural unit is derived from a compound represented by the formula (II ′) (hereinafter sometimes referred to as “compound (II ′)”).

[All of the symbols in formula (II ′) have the same meaning as described above. ]

  Compound (II ′) can be produced, for example, by the method described in JP2011-148967A or according to this method.

  The content ratio of the second structural unit in the resin (A) is usually in the range of 1 to 40 mol% and preferably in the range of 2 to 35 mol% with respect to all the structural units of the resin (A). It is more preferable in the range of 3 to 30 mol%, and further preferable in the range of 3 to 20 mol%. However, this content ratio is preferably determined in consideration of the content ratios of the first structural unit, the second structural unit, and the third structural unit described later.

Next, the third structural unit will be described.
The third structural unit is a structural unit having an acid labile group. A structural unit having an acid labile group (hereinafter sometimes referred to as “acid labile structural unit”) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “acid labile monomer (a1)”). .
Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

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

［式（２）中、
Ｒ^ａ１’及びＲ^ａ２’は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ３’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^ａ２’及びＲ^ａ３’は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基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。］

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

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

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

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

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

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

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

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

  The third structural unit is a monomer having an acid labile group [hereinafter referred to as “monomer (a1)” in some cases. ] Is derived from. The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid labile group.

  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 more preferred. Since the resin (A) obtained using such a monomer (a1) has a bulky structure such as an alicyclic hydrocarbon group, the resolution of the resist composition tends to be better. is there.

  Among the third structural units, the structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as “structural unit (a1-1)”) or the structural unit represented by the formula (a1-2) ( Hereinafter, the “structural unit (a1-2)” is sometimes preferable. The resin (A) having the third structural unit may have a single structural unit (a1-1) or a plurality of structural units (a1-2). You may have by seed | species, you may have multiple types, and you may have combining the structural unit (a1-1) and the structural unit (a1-2).

［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のアルキル基又は炭素数３〜１０の脂環式炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ１’は０〜３の整数を表す。］

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent 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 or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

ｍ１は、好ましくは０〜３の整数、より好ましくは０又は１である。
ｎ１は、好ましくは０〜３の整数、より好ましくは０又は１である。
ｎ１’は好ましくは０又は１である。 L ^a1 and L ^a2 are preferably an oxygen atom or a group represented by * —O— (CH ₂ ) _k1 —CO—O—, wherein k1 is an integer of 1 to 4, more preferably an oxygen atom. or * -O-CH ₂ -CO-O- and, still more preferably an oxygen atom.
R ^a4 and R ^a5 are preferably methyl groups.
The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an alkyl group. . In this case, the carbon number of the alicyclic hydrocarbon group is 10 or less including the carbon number of the alkyl group. Specific examples include the same groups as the alicyclic hydrocarbon groups represented by R ^a1 , R ^a2 and R ^a3 in formula (1).

m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As the structural unit (a1-1), the following formula (a1-1-1), formula (a1-1-2), formula (a1-1-3), formula (a1-1-4), formula ( a1-1-5), the formula (a1-1-6), the formula (a1-1-7), and the structural unit represented by the formula (a1-1-8) are preferable, and the formula (a1-1-1) is preferable. ) To (a1-1-4) are more preferred.

  Examples of the monomer (a1) capable of deriving the structural unit (a1-1) include those described in JP 2010-204646 A.

式（ａ１−２）で表される構造単位を誘導するモノマーとしては、例えば、１−エチルシクロペンタン−１−イル（メタ）アクリレート、１−エチルシクロヘキサン−１−イル（メタ）アクリレート、１−エチルシクロヘプタン−１−イル（メタ）アクリレート、１−メチルシクロペンタン−１−イル（メタ）アクリレート及び１−イソプロピルシクロペンタン−１−イル（メタ）アクリレートなどが挙げられる。 On the other hand, as the structural unit (a1-2), for example, the formula (a1-2-1), the formula (a1-2-2), the formula (a1-2-3), the formula (a1-2-4), Formula (a1-2-5), Formula (a1-2-6), Formula (a1-2-7), Formula (a1-2-8), Formula (a1-2-9), Formula (a1-2) -10), structural units represented by formula (a1-2-11) or formula (a1-2-12), respectively. Among these, the structural unit represented by the formula (a1-2-3), the formula (a1-2-4), the formula (a1-2-9), or the formula (a1-2-10) is preferable. The structural unit represented by (a1-2-3) or formula (a1-2-9) is more preferable.

Examples of the monomer for deriving the structural unit represented by the formula (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, 1- Examples include ethylcycloheptan-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 third structural unit, the total content thereof is based on the total structural unit of the resin (A). The range of 10-95 mol% is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is more preferable. However, this content ratio is also preferably determined in consideration of the content ratios of the first structural unit, the second structural unit, and the third structural unit described later.

［式（ａ１−５）中、
Ｒ³⁵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、Ｌ^２及びＬ^３は、それぞれ独立に、酸素原子、硫黄原子又は^＊−Ｏ−（ＣＨ₂）_k４−ＣＯ−Ｏ−で表される基を表す。ここで、ｋ４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。
Ｚ^１は、単結合又は炭素数１〜６のアルカンジイル基であり、該アルカンジイル基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ｓ１及びｓ１’は、それぞれ独立して、０〜４の整数を表す。］ Although the structural unit (a1-1) and the structural unit (a1-2) containing the acid labile group (1) have been described, the resin (A) is, for example, a third structural unit containing the acid labile group (2). And a third structural unit other than the structural unit (a1-1) and the structural unit (a1-2). As a monomer capable of deriving the third structural unit containing the acid labile group (2), one represented by the following formula (a1-5) (hereinafter sometimes referred to as “monomer (a1-5)”). Can be mentioned.

[In the formula (a1-5),
R ³⁵ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ¹ , L ² and L ³ each independently represent an oxygen atom, a sulfur atom or a group represented by ^* —O— (CH ₂ ) _k4 —CO—O—. Here, k4 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
Z ¹ is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group constituting 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 ratio thereof is preferably in the range of 1 to 50 mol% with respect to all the structural units of the resin (A). The range of 45 mol% is more preferable, and the range of 5 to 40 mol% is more preferable.

  The content ratio (molar ratio) of the first structural unit, the second structural unit, and the third structural unit in the resin (A) is [content of first structural unit] / [content of second structural unit]. / [Content of third structural unit], preferably [3-80] / [2-40] / [10-95], specifically [3-80 mol%] / [2 -40 mol%] / [10-95 mol%], preferably [3-75 mol%] / [2-35 mol%] / [15-95 mol%] (where, The total of [content of first structural unit], [content of second structural unit] and [content of third structural unit] is 100 mol%). This content ratio induces the compound (I ′) that induces the first structural unit, the compound (II ′) that induces the second structural unit, and the third structural unit in the production of the resin (A) described later. It can adjust with the usage-amount of a monomer (a1).

  Since the resin (A) has the third structural unit, it is decomposed by the action of an acid (the third structural unit of the resin (A) is decomposed by the action of an acid), and is used in a resist pattern manufacturing method described later. Converts to a different solubility in developer. When the developer is a general-purpose alkaline aqueous solution, the resin (A) subjected to the action of an acid tends to increase the solubility in the alkaline aqueous solution. On the other hand, when the developer is composed of an organic solvent, that is, a solvent containing an organic solvent, the resin (A) subjected to the action of an acid tends to be less soluble in the developer.

<Other structural units (acid stable structural units)>
As described above, the resin (A) has the first structural unit, the second structural unit, and the third structural unit, but may optionally have a structural unit other than these, and the structural unit in this case Are those having no acid labile group (hereinafter, sometimes referred to as “acid-stable structural unit”, and a monomer capable of deriving the acid-stable structural unit is referred to as “acid-stable monomer”). In the resin (A), the acid stable structural unit may have only one type or may have a plurality of types.

  When the resin (A) has an acid stable structural unit, the content ratio of the acid stable structural unit may be determined based on the content ratios of the first structural unit, the second structural unit, and the third structural unit. More specifically, the ratio of the content ratio of each of the first structural unit, the second structural unit, and the third structural unit to the content ratio of the acid-stable structural unit is determined by the first structural unit, the second structural unit, and the third structural unit. The ratio between the content ratio of each structural unit and the content ratio of the acid-stable structural unit is [content of first structural unit], [content of second structural unit], [content of third structural unit] and Expressed as a ratio of [content of acid stable structural unit] to 100 mol% in total of [content of acid stable structural unit], preferably in the range of 5 to 75 mol%, more preferably 10 to 70 mol. % Range.

  The acid stable structural unit is preferably an acid stable structural unit having a hydroxy group or a lactone ring. Resin (A) has a coating film formed by applying the present resist composition to a substrate or a composition layer obtained from the coating film in the production of a resist pattern described later by the action of the first structural unit. However, if it further has an acid stable structural unit having a hydroxy group or a lactone ring, the adhesion is further improved. Here, the acid stable structural unit having a hydroxy group is hereinafter referred to as “acid stable structural unit (a2)”, and the acid stable structural unit having a lactone ring is sometimes referred to as “acid stable structural unit (a3)”. I will say. The acid stable structural unit (a3) here does not include the first structural unit. First, the acid stable structural unit (a2) and the acid stable structural unit (a3) suitable as the acid stable structural unit will be described with specific examples.

  When the acid stable structural unit (a2) is introduced into the resin (A), a suitable acid stable structural unit (a2) can be selected depending on the type of exposure source used in the production of the resist pattern described later. That is, when this resist composition is exposed using a short-wavelength ArF excimer laser (wavelength: 193 nm) as an exposure source, it is represented by the formula (a2-1) described later as an acid stable structural unit (a2). It is preferable to introduce an acid stable structural unit into the resin (A). Further, the present resist composition is exposed using a KrF excimer laser (wavelength: 248 nm) as an exposure source, or exposure using a high energy beam such as an electron beam or EUV light as an exposure source. In the specification, it is referred to as “exposure”, and the electron beam is also considered as one of “exposure sources”.) When used for acid stable structural unit (a2), an acid stable structural unit having a phenolic hydroxy group is used. It may be introduced. The acid-stable structural unit (a2) of the resin (A) can be selected depending on the exposure source when producing the resist pattern, but when the resin (A) has the acid-stable structural unit (a2), The acid stable structural unit (a2) may be a single species or a plurality of species.

式（ａ２−１）中、
Ｌ^a3は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−（ｋ２は１〜７の整数を表し、＊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。 A preferable acid stable structural unit (a2) in the case of using ArF excimer laser (wavelength: 193 nm) exposure for the resist composition is represented by the following formula (a2-1) (hereinafter, “acid stable structural unit ( a2-1) ”).

In formula (a2-1),
L ^a3 is an oxygen atom or ^* —O— (CH ₂ ) _k2 —CO—O— (k2 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 ) _k2 —CO—O—, wherein k2 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 an acid stable structural unit (a2-1), the following are mentioned, for example.

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

  When the resin (A) has an acid stable structural unit (a2-1), the content ratio is preferably in the range of 1 to 45 mol%, and 1 to 40 mol% with respect to all the structural units of the resin (A). The range of 1 to 35 mol% is more preferable, the range of 1 to 20 mol% is still more preferable.

Next, the acid stable structural unit (a3) having a lactone ring will be described.
The lactone ring of the acid stable structural unit (a3) is not particularly limited as long as it is other than the adamantane ring-like lactone ring of the first structural unit. For example, β-propiolactone ring, γ-butyrolactone ring and A monocyclic ring such as a δ-valerolactone ring or a condensed ring of a monocyclic lactone ring and another ring may be used.

［式（ａ３−１）中、
Ｌ^a4は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）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のアルキル基を表し、ｐ１が２以上の場合、複数のＲ^a21は互いに同一でも異なっていてもよい。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）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のアルキル基を表し、ｑ１が２以上の場合、複数のＲ^a22は互いに同一でも異なっていてもよい。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）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のアルキル基を表し、ｒ１が２以上の場合、複数のＲ^a23は互いに同一でも異なっていてもよい。］ The acid stable structural unit (a3) is preferably one represented by the following formula (a3-1), formula (a3-2) or formula (a3-3). Resin (A1) may have only 1 type in these, and may have 2 or more types. In the following description, what is represented by the formula (a3-1) is referred to as “acid-stable structural unit (a3-1)”, and what is represented by the formula (a3-2) is “acid-stable structural unit ( a3-2) ”, and the compound represented by formula (a3-3) is referred to as“ acid-stable structural unit (a3-3) ”.

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

In formula (a3-1), formula (a3-2) and formula (a3-3), L ^a4 , L ^a5 and L ^a6 are the same as those described for L ^a3 in formula (a2-1). It is done.
L ^a4 , L ^a5 and L ^a6 are each independently preferably an oxygen atom or a group represented by * —O— (CH ₂ ) _k3 —CO—O—, wherein k3 is an integer of 1 to 4. An atom and * —O—CH ₂ —CO—O— are more preferable, and an oxygen atom is more preferable.
R ^a18 , R ^a19 , R ^a20 and R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are preferably integers of 0 to 2, more preferably 0 or 1. When p1 is 2, two R ^a21 may be the same as or different from each other. When q1 is 2, two R ^a22 may be the same as or different from each other, and r1 is 2. Two R ^a23 may be the same or different from each other.

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

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

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

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

  The acid stable structural unit (a3-1), the acid stable structural unit (a3-2), and the acid stable structural unit (a3-3) can be derived from an acid stable monomer described in JP 2010-204646 A. Among the specific examples of the acid stable structural unit (a3), the formula (a3-1-1), the formula (a3-1-2), the formula (a3-2-3), and the formula (a3-2-4) ) Are more preferable, and the acid stable structural unit (a3) represented by the formula (a3-1-1) or the formula (a3-2-3) is more preferable. In addition, when resin (A) has an acid stable structural unit (a3), this acid stable structural unit (a3) may be single type, or may be multiple types.

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

  Further, the resin (A) may have an acid stable structural unit other than the acid stable structural unit (a2) and the acid stable structural unit (a3) as long as the acid action characteristics are not significantly impaired. .

  The resin (A) is more preferably a compound (I ′) for deriving the first structural unit, a compound (II ′) for deriving the second structural unit, and a monomer (a1) for deriving the third structural unit. Is a copolymer of compound (I ′), compound (II ′), monomer (a1), and acid stable monomer, and more preferably compound (I ′), compound (II ′) ), A monomer (a1) for deriving structural unit (a1-1) and / or structural unit (a1-2), and an acid for deriving acid stable structural unit (a2) and / or acid stable structural unit (a3) Copolymerized with a stable monomer. When the monomer (a1) for deriving the structural unit (a1-2) is used, the monomer (a1) having a cyclohexyl group or a cyclopentyl group is preferable, but the third structural unit is the structural unit (a1-1). Those having an adamantyl group are more preferred. The resin (A) can be produced by subjecting the monomer as described above to a known polymerization method (for example, radical polymerization method) and copolymerizing it.

  The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, and further preferably 15,000 or less). 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.

This resist composition contains the above-mentioned resin (A) and an acid generator (B).
The resist composition contains the resin (A) as a resin component, but the resin component may contain a resin other than the resin (A). Examples of the resin other than the resin (A) include resins known in the resist field such as a resin obtained by removing the first structural unit and / or the second structural unit from the resin (A).

  In the present resist composition, the content ratio of the resin component is preferably 80% by mass or more and 99% by mass or less with respect to the solid content of the present resist composition. As described above, the resin component may contain a resin other than the resin (A), but the resin (A) is preferably 50% by mass or more, and 70% by mass with respect to the total amount of the resin component. The above is more preferable, and it is particularly preferable that the resin component substantially consists of the resin (A). In the present specification, the “solid content” means the total of the resist composition components excluding the solvent (E) described later. The solid content and the content ratio of the resin component to the solid content can be measured by a known analysis means such as liquid chromatography or gas chromatography, for example.

<Acid generator (B)>
In the resist field, acid generators are usually classified into nonionic and ionic types, but the acid generator (B) contained in the resist composition may be a nonionic acid generator, even if it is a nonionic acid generator. These acid generators may be used in combination. Examples of the nonionic acid generator include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonate), and sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, and JP-A 63-163452. JP-A-62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent 3914407, European Patent 126, Compounds that generate an acid by radiation, such as those described in No. 712, can also be used.

［式（Ｂ１）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、炭素数１〜２４の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置き換わっていてもよく、該飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、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、水素原子又はフッ素原子を表し、該脂環式炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］
かかる酸発生剤（Ｂ１）を含有する本レジスト組成物は、後述のレジストパターンの製造方法により、断面形状がより優れたレジストパターンを製造できる。 The acid generator (B) is preferably a fluorine-containing acid generator, more preferably an acid generator represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”). .

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, and methylene constituting the saturated hydrocarbon group The group may be replaced by an oxygen atom or a carbonyl group.
Y represents an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, a hydrogen atom or a fluorine atom, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A sulfonyl group or a carbonyl group may be substituted.
Z ⁺ represents an organic cation. ]
This resist composition containing such an acid generator (B1) can produce a resist pattern having a more excellent cross-sectional shape by a method for producing a resist pattern described later.

Examples of the perfluoroalkyl group represented by Q ¹ and Q ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluorotert-butyl group, A perfluoropentyl group, a perfluorohexyl group, etc. are mentioned.
As the acid generator (B1) contained in the resist composition, Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom acid generator (B1). Q ¹ and Q ² An acid generator (B1) in which both are fluorine atoms is more preferred.

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

Examples of the saturated hydrocarbon group represented by L ^{b1 in} which a methylene group is replaced by an oxygen atom or a carbonyl group include the following formula (b1-1), formula (b1-2), formula (b1-3), Groups represented by formula (b1-4), formula (b1-5), formula (b1-6) and formula (b1-7) [formula (b1-1) to formula (b1-7)], respectively. It is done. Incidentally, the formula (b1-1) ~ formula represents a bond in (b1-7) * is described in conjunction the right in equation (B1), the left bond is, C (Q ¹⁾ ( Q ² ) is bonded to the carbon atom, and the right bond is bonded to Y. The same applies to specific examples of the following formulas (b1-1) to (b1-7).

In formula (b1-1) to formula (b1-7),
L ^b2 represents a single bond or a saturated hydrocarbon group having 1 to 22 carbon atoms, preferably 1 to 15 carbon atoms.
L ^b3 represents a single bond or a saturated hydrocarbon group having 1 to 19 carbon atoms, preferably 1 to 12 carbon atoms.
L ^b4 represents a saturated hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 13 carbon atoms. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 20, preferably 13.
L ^b5 represents a single bond or a saturated hydrocarbon group having 1 to 21 carbon atoms, preferably 1 to 14 carbon atoms.
L ^b6 represents a saturated hydrocarbon group having 1 to 22 carbon atoms, preferably 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b5 and L ^b6 is 22, preferably 15.
L ^b7 represents a single bond or a saturated hydrocarbon group having 1 to 22 carbon atoms, preferably 15 carbon atoms.
L ^b8 represents a saturated hydrocarbon group having 1 to 23 carbon atoms, preferably 1 to 16 carbon atoms. However, the upper limit of the total carbon number of L ^b7 and L ^b8 is 23, preferably 1-17.
L ^b9 represents a single bond or a saturated hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 13 carbon atoms.
L ^b10 represents a saturated hydrocarbon group having 1 to 21 carbon atoms, preferably 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 21, preferably 14.
L ^b11 and L ^{b12 each} represents a single bond or a saturated hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 11 carbon atoms.
L ^b13 represents a saturated hydrocarbon group having 1 to 19 carbon atoms, preferably 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b11 , L ^b12 and L ^b13 is 19, preferably 12.
L ^b14 and L ^b15 each independently represent a single bond or a saturated hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 13 carbon atoms.
L ^b16 represents a saturated hydrocarbon group having 1 to 21 carbon atoms, preferably 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b14 , L ^b15 and L ^b16 is 21, preferably 14.

The saturated hydrocarbon group in L ^{b2 to} L ^b16 is preferably an alkanediyl group, and the saturated hydrocarbon group in L ^b13 is preferably an alkanediyl group or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, A group, a cyclohexyl group and an adamantyl group are more preferred.
L ^b1 is preferably any one of formula (b1-1) to formula (b1-4), more preferably formula (b1-1) or formula (b1-2), and still more preferably formula (b1-1). A divalent group represented by formula (b1-1) in which L ^b2 is a single bond or —CH ₂ —.

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 alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y26).

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

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

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group.
Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the aromatic hydrocarbon group include those similar to the above.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of Y include the following.

  Y is preferably an alicyclic hydrocarbon group which may have a substituent, more preferably an adamantyl group which may have a substituent (for example, a hydroxy group), or a methylene group is carbonyl. An adamantyl group replaced by a group, more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group;

Preferable examples of the sulfonate anion constituting the acid generator (B1) include anions represented by formulas (b1-1-1) to (b1-1-9), respectively. In the following formulas, the definitions of the symbols have the same meaning as described above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group). Specific examples of the sulfonate anion include the anions described in JP 2010-204646 A.

Next, the organic cation (cation) constituting the acid generator (B1) will be described. The cation functions as a light absorption part of the acid generator (B1), and various cations used as the light absorption part in the ionic acid generator used in the resist field can be mentioned. Examples include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, organic benzothiazolium cations, and organic phosphonium cations. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an organic sulfonium cation is more preferable. Specific examples of preferred cations are organic cations represented by the following formulas (b2-1) to (b2-4) [hereinafter referred to as “cation (b2-1)” according to the number of each formula]. , “Cation (b2-2)”, “cation (b2-3)” and “cation (b2-4)”. ].

In formula (b2-1) to formula (b2-4),
R ^b4 , R ^b5 and R ^b6 each independently represent a hydrocarbon group having 1 to 30 carbon atoms, and among these hydrocarbon groups, an alkyl group having 1 to 30 carbon atoms and an oil having 3 to 18 carbon atoms A cyclic hydrocarbon group and an aromatic hydrocarbon group having 6 to 18 carbon atoms are preferred. The alkyl group may have a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon group includes a halogen atom and a carbon number. The aromatic hydrocarbon group may have 2 to 4 acyl groups or glycidyloxy groups, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms, or an alicyclic group having 3 to 18 carbon atoms. You may have a hydrocarbon group or a C1-C12 alkoxy group.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.
R ^b9 and R ^b10 each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b9 , R ^b10 and R ^b11 (R ^{b9 to} R ^b11 ) are each independently an alkyl group, preferably a carbon number in the range of 1 to 12, and an alicyclic hydrocarbon group. The number of carbon atoms is preferably in the range of 3-18, more preferably in the range of 4-12.
R ^b12 represents a hydrocarbon group having 1 to 18 carbon atoms. Among these hydrocarbon groups, the aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 1 to 12 carbon atoms. It may have an alkylcarbonyloxy group.
The combination of R ^b9 and R ^b10 and / or the combination of R ^b11 and R ^b12 are independently bonded to each other to form a 3-membered ring to 12-membered ring (preferably a 3-membered ring to 7-membered ring). These 3-membered ring to 12-membered ring (preferably 3-membered ring to 7-membered ring) may be an aliphatic ring or a methylene group constituting the aliphatic ring may be an oxygen atom, a sulfur atom or A ring that replaces a carbonyl group.

^{R b13, R b14, R b15} , R b16, R b17 and R ^b18 (R ^b13 ~R ^b18) are each independently a hydroxy group, an alkyl group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms Represents.
L ^b11 represents an oxygen atom or a sulfur atom.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 may be the same or different. When p2 is 2 or more, the plurality of R ^b14 are independent, and when s2 is 2 or more, a plurality of R ^{b13 b15} may be the same or different, and when t2 is 2 or more, a plurality of ^Rb18 may be the same or different.

The alkylcarbonyloxy group represented by R ^b12 is a group in which an acyl group exemplified above and an oxygen atom are bonded.

^Examples of the alkyl group represented by R ^b9 , R ^b10 , R ^b11 and R ^b12 (R ^{b9 to} R ^b12 ) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a sec-butyl group. Tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group.
Examples of the alicyclic hydrocarbon group represented by R ^{b9 to} R ^b11 include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyladamantan-2-yl group, 1- (1-adamantyl) alkane-1-yl group and isobornyl group.
^Examples of the aromatic hydrocarbon group represented by R ^b12 include a phenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-cyclohexylphenyl group, and a 4-methoxyphenyl group. A biphenylyl group and a naphthyl group.
A ^combination of an aromatic hydrocarbon group represented by R ^b12 and an alkyl group is typically an aralkyl group.
Examples of the ring formed by combining the combination of R ^b9 and R ^b10 include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Is mentioned.
Examples of the ring formed by combining the combination of R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Specific examples of the organic cation represented by each of the formulas (b2-1) to (b2-4) include those described in JP 2010-204646 A.

Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, the cation represented by the formula (b2-1-1) is more preferable, and the triphenylsulfonium cation (formula (b2) -1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (in formula (b2-1-1), v2 = w2 = 0, x2 = 1, and R ^b21 is a methyl group .) Or tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 1, and R ^b19 , R ^b20 and R ^b21 are all methyl groups).

式（ｂ２−１−１）中、
Ｒ^b19、Ｒ^b20及びＲ^b21（Ｒ^b19〜Ｒ^b21）は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）ヒドロキシ基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基又は炭素数３〜１８の脂環式炭化水素基を表す。また、Ｒ^b19〜Ｒ^b21から選ばれる２つが一緒になって硫黄原子を含む環を形成してもよい。
ｖ２、ｗ２及びｘ２は、それぞれ独立に０〜５の整数（好ましくは０又は１）を表す。
ｖ２が２以上のとき、複数のＲ^b19は同一又は相異なり、ｗ２が２以上のとき、複数のＲ^b20は同一又は相異なり、ｘ２が２以上のとき、複数のＲ^b21は同一又は相異なる。

In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 (R ^{b19 to} R ^b21 ) are each independently a halogen atom (more preferably a fluorine atom) hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. Or an alicyclic hydrocarbon group having 3 to 18 carbon atoms is represented. It is also possible that two selected from R ^b19 to R ^b21 together form a ring containing a sulfur atom.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, the plurality of R ^b19 are the same or different, when w2 is 2 or more, the plurality of R ^b20 are the same or different, and when x2 is 2 or more, the plurality of R ^b21 are the same or different. .

Among these, R ^{b19 to} R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

  Specific examples of the cation include those described in JP2010-204646A.

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anion and cation can be arbitrarily combined, but preferably any one of the sulfonate anions of (b1-1-1) to (b1-1-9) and (b2-1-1) A combination with an organic cation, and a combination of any of the sulfonate anions of (b1-1-3) to (b1-1-5) and the organic cation of (b2-3) can be mentioned.

  As the acid generator (B1), those represented by the formula (B1-1) to the formula (B1-20) are more preferable, and the formula (B1-1) and the 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) or formula (B1-20) is particularly preferable.

The content of the acid generator (B) is preferably 1 part by mass or more and 30 parts by mass or less, and more preferably 3 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the resin (A).
The acid generator (B) contained in the resist composition may contain a single kind or a plurality of kinds of acid generators, but even when it contains a plurality of kinds of acid generators, at least one kind is contained. The acid generator (B1) is preferable, and it is more preferable that substantially all of the acid generator (B) is composed of the acid generator (B1).

<Solvent (E)>
In order to use this resist composition for the resist pattern manufacturing method mentioned later, this resist composition preferably contains a solvent (E), particularly an organic solvent as a solvent (E). The solvent depends on the type and amount of the resin (A) to be used, the type and amount of the acid generator (B), and the resist composition is applied onto the substrate in the production of a resist pattern described later. From the viewpoint that the applicability of the coating becomes good, an optimal one can be selected as appropriate.

  When this resist composition contains a solvent (E), the content ratio is 90 mass% or more with respect to the total amount of this resist composition, for example, Preferably it is 92 mass% or more, More preferably, it is 94 mass% or more. For example, it is 99.9% by mass or less, preferably 99% by mass or less. The content ratio of the solvent (E) can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and 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 (E) may contain 1 type independently, and may contain 2 or more types.

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition may contain a basic compound (C) called “quencher” in the resist field.
The basic compound (C) is a compound having a property of capturing an acid, particularly a compound having a property of capturing an acid generated from the acid generator (B).

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

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

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

［式（Ｃ１−１）中、
Ｒ^c2及びＲ^c3は、上記と同じ意味を表す。
Ｒ^c4は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4は同一又は相異なる。］

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

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、
Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は同一又は相異なる。］
なお、ここでいうアルカノイル基としては、アセチル基、２−メチルアセチル基、２，２−ジメチルアセチル基、プロピオニル基、ブチリル基、イソブチリル基、ペンタノイル基及び２，２−ジメチルプロピオニル基などである。

[In Formula (C2), Formula (C3) and Formula (C4),
R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 are the same or different. ]
The alkanoyl group mentioned here includes an acetyl group, a 2-methylacetyl group, a 2,2-dimethylacetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pentanoyl group, and a 2,2-dimethylpropionyl group.

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

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

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

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

Specific examples of the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, alkoxy group and alkanediyl group in the formulas (C1) to (C8) are those already exemplified in the respective carbon number ranges. including.
Specific examples of the alkanoyl group include the same as those described for R ^c9 in formula (C4).

  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 thereof include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, and 4,4′-diamino-3,3′-diethyldiphenylmethane. Propyl aniline. Particularly preferred include 2,6-diisopropylaniline.

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

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

  When the basic compound (C) is contained in the resist composition, the content ratio is preferably about 0.01 to 5% by mass, more preferably about 0.005% by mass, based on the solid content of the resist composition. It is about 01 to 3% by mass, particularly preferably about 0.01 to 1% by mass.

<Other components (hereinafter sometimes referred to as “component (F)”)>
The present resist composition may contain a component (F) as necessary. The component (F) includes additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes. When the component (F) is used in the resist composition of the present invention, an appropriate content can be adjusted according to the type of the component (F).

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

The method for producing a resist pattern of the present invention (hereinafter sometimes referred to as “the present production method”)
(1) A step of applying the resist composition on a substrate (application step),
(2) A step of drying the composition after coating to form a composition layer (drying step),
(3) Step of exposing the composition layer (exposure step),
(4) Step of heating composition layer after exposure (heating step), and (5) Step of developing composition layer after heating (development step)
including.

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

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

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

The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The composition layer after heating is usually developed with a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., and the development time is preferably 5 to 300 seconds.

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

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

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

<Application>
The resist composition includes a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, in particular, ArF excimer. It is suitable as a resist composition for immersion exposure for laser exposure.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

式（Ｋ−１）で表される化合物３３．４８部、ジシクロヘキシルカルボジイミド２３．９３部及び塩化メチレン４０．００部を、反応器に仕込み、混合した。得られた混合物を０℃程度まで冷却した後、式（Ｋ−２）で表される化合物１８．８３部を加え、０℃程度のまま、１時間攪拌した。２３℃まで昇温し、さらに３０分間攪拌した。不溶物をろ過して除去し、得られたろ液を濃縮して、式（Ｋ−３）で表される化合物４４．２８部を得た。 Synthesis Example 1 (Synthesis of monomer (M-K))

33.48 parts of the compound represented by the formula (K-1), 23.93 parts of dicyclohexylcarbodiimide and 40.00 parts of methylene chloride were charged into a reactor and mixed. After cooling the obtained mixture to about 0 ° C., 18.83 parts of the compound represented by the formula (K-2) was added, and the mixture was stirred for about 1 hour while maintaining about 0 ° C. The temperature was raised to 23 ° C., and the mixture was further stirred for 30 minutes. Insoluble matters were removed by filtration, and the obtained filtrate was concentrated to obtain 44.28 parts of a compound represented by the formula (K-3).

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

A reactor was charged with 19.42 parts of the compound represented by the formula (K-3) obtained as described above, 18.22 parts of the compound represented by the formula (K-4) and 200 parts of acetonitrile. 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. The concentrate is subjected to column fractionation (column fractionation conditions stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., Ltd. developing solvent: ethyl acetate) to obtain 12.89 parts of a compound represented by the formula (M-K). It was.
MS (mass spectrometry): 308.1 (molecular ion peak)

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

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

Example 1 [Synthesis of Resin A1]
As a monomer, a monomer (MG), a monomer (ME), a monomer (MB), a monomer (M-H), a monomer (M-K), and a monomer (ML), and their molar ratio (Monomer (MG): monomer (ME): monomer (MB): monomer (MH): monomer (MK): monomer (ML)) is 32: 7: 8: It mixed so that it might become 37: 10: 6, 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. 9 × 10 ³ resin A1 (copolymer) was obtained in a yield of 82%. This resin A1 has the following structural units.

Example 2 [Synthesis of Resin A2]
As a monomer, a monomer (MF), a monomer (M-I), a monomer (M-J), a monomer (MD), a monomer (M-K) and a monomer (ML) are used, and the molar ratio thereof. (Monomer (MF): monomer (MI): monomer (MJ): monomer (MD): monomer (MK): monomer (ML)) 45: 14: 2. 5: 15: 16.5: 7 was mixed, and 1.5 mass times the total amount of dioxane was added to form a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice, and the weight average molecular weight is 8. 5 × 10 ³ resin A2 (copolymer) was obtained with a yield of 67%. This resin A2 has the following structural units.

Example 3 [Synthesis of Resin A3]
As the monomer, monomer (MF), monomer (M-I), monomer (M-J), monomer (MD), monomer (M-H), monomer (M-K) and monomer (ML) ) And its molar ratio (monomer (MF): monomer (M-I): monomer (M-J): monomer (MD): monomer (M-H): monomer (M-K): Monomers (ML)) were mixed at 45: 14: 2.5: 10: 6: 16.5: 6, and 1.5 mass times dioxane of the total monomer amount was added to make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, 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. 2 × 10 ³ resin A3 (copolymer) was obtained in a yield of 63%. This resin A3 has the following structural units.

Example 4 [Synthesis of Resin A4]
As a monomer, a monomer (MF), a monomer (M-I), a monomer (M-J), a monomer (M-K) and a monomer (ML) are used, and the molar ratio (monomer (M-F)) : Monomer (M-I): Monomer (M-J): Monomer (M-K): Monomer (M-L)) were mixed so as to be 45: 14: 2.5: 31.5: 7, Dioxane of 1.5 mass times the total monomer amount was added to make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, 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. 0 × 10 ³ resin A4 (copolymer) was obtained with a yield of 60%. This resin A4 has the following structural units.

Example 5 [Synthesis of Resin A5]
As a monomer, a monomer (MG), a monomer (M-I), a monomer (M-B), a monomer (M-K), and a monomer (ML) are used, and the molar ratio (monomer (M-G) : Monomer (M-I): Monomer (M-B): Monomer (M-K): Monomer (M-L)) are mixed so as to be 30: 14: 6: 20: 30, and the total amount of monomers Of 1.5 mass times of dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight average molecular weight was 8.1. × give 10 ^third resin A5 (copolymer) in 78% yield. This resin A5 has the following structural units.

Example 6 [Synthesis of Resin A6]
As a monomer, a monomer (MG), a monomer (M-I), a monomer (M-J), a monomer (M-K), and a monomer (ML) are used, and the molar ratio (monomer (MG) : Monomer (M-I): Monomer (M-J): Monomer (M-K): Monomer (M-L)) were mixed so as to be 35: 15: 3: 27: 20, and the total amount of monomers Of 1.5 mass times of dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 8.3. A × 10 ³ resin A6 (copolymer) was obtained in a yield of 80%. This resin A6 has the following structural units.

Synthesis Example 2 [Synthesis of Resin H1]
As the monomer, monomer (MA), monomer (MB) and monomer (MI) are used, and the molar ratio thereof (monomer (MA): monomer (MB): monomer (MI)) ) Was 40:20:40, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 78 ° 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 reprecipitation operation of filtering the resin was performed twice, and the weight average molecular weight 6. 5 × 10 ³ resin H1 (copolymer) was obtained with a yield of 85%. This resin H1 has the following structural units.

Examples 7 to 10 and Comparative Example 1
<Preparation of resist composition>
Each of the components shown below was dissolved in a solvent in parts by mass shown in Table 1, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

In addition, each code | symbol shown in Table 1 and Table 4 represents the following components, respectively.
<Resin>
A1 to A6, H1: Resin A1 to Resin A6, Resin H1
<Acid generator>
B1: Synthesis according to the example of JP 2010-152341 A

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

<Solvent>
Propylene glycol monomethyl ether acetate 265.0 parts Propylene glycol monomethyl ether 20.0 parts 2-heptanone 20.0 parts γ-butyrolactone 3.5 parts

<Immersion exposure evaluation of resist composition>
(1) Application process By applying a composition for organic antireflection film [ARC-29; manufactured by Nissan Chemical Co., Ltd.] on a 12-inch silicon wafer and baking at 205 ° C. for 60 seconds, An organic antireflection film having a thickness of 78 nm was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) (the film thickness of the composition layer) was 100 nm.
(2) Drying Step After the coating step, the silicon wafer on which the coating film was formed was pre-baked (PB) for 60 seconds on the direct hot plate at the temperature described in the “PB” column of Table 1. Thus, a composition layer was formed on the silicon wafer.
(3) Exposure process A silicon wafer on which the composition layer is formed is lined with an ArF excimer stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized illumination]. Using a mask (pitch 100 nm / space 50 nm) for forming an and-space pattern (pitch 100 nm / line 50 nm), the exposure was changed stepwise. Note that ultrapure water was used as the immersion medium.
(4) Heating step After exposure, post-exposure baking (PEB) was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 1.
(5) Development process The composition layer on the silicon wafer after the heating process is subjected to paddle development for 20 seconds using butyl acetate (using n-butyl acetate purchased from Tokyo Kasei as it is) as a developer, A pattern was manufactured.

  In each composition layer, an exposure amount at which a line pattern formed with a mask having a pitch of 100 nm / space of 50 nm becomes 50 nm was defined as effective sensitivity.

<Shape evaluation>
A line pattern of 50 nm line and space pattern was observed with a scanning electron microscope. The determination was made on the basis of two levels, with a top shape close to a rectangle being good (FIG. 1A) and a round top shape [FIG. 1B] x. The results are shown in Table 2.

Examples 11 to 13 and Comparative Example 2
The same as each of Examples 1 to 3 and Comparative Example 1, except that the developer used in the development process was changed from n-butyl acetate to 2-heptanone (the one purchased from Kyowa Hakko Co., Ltd. was used as it was). Experiments were performed and the shape was observed. The results are shown in Table 3.

  In resist pattern manufacture of Examples 7 to 14, resist patterns (negative resist patterns) could be manufactured with shapes superior to those of Comparative Pattern 1 and Comparative Example 2.

Examples 15 to 17 and Comparative Example 3
<Preparation of resist composition>
Each of the components shown below was dissolved in the following solvent in the parts by mass shown in Table 4 and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Manufacture of resist pattern and its evaluation>
<Evaluation of line edge roughness (LER) after immersion exposure of resist composition>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 78 nm. An organic antireflection film was formed. Next, the above resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) was 85 nm.
The obtained silicon wafer was pre-baked (PB) for 60 seconds on a direct hot plate at the temperature described in the “PB” column of Table 4. The wafer with the resist composition film thus formed was subjected to an immersion exposure ArF excimer stepper [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light], and a line and space pattern (pitch 100 nm). The line and space pattern was subjected to immersion exposure using a mask (pitch: 100 nm / space: 50 nm) for forming a line / space pattern by changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, post exposure bake (PEB) is performed on the hot plate at the temperature described in the “PEB” column of Table 4 for 60 seconds, and further with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 60 seconds. Paddle development was performed to obtain a resist pattern.

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

<Shape evaluation>
A line pattern of 50 nm line and space pattern was observed with a scanning electron microscope. The determination was made on the basis of two levels, with a top shape close to a rectangle being good (FIG. 1A) and a round top shape [FIG. 1B] x. The results are shown in Table 5.

  The resist composition of the present invention can be used for fine processing of semiconductors.

Claims (8)

A resist resin having a first structural unit represented by the formula (I), a second structural unit represented by the formula (II), and a third structural unit containing an acid labile group.

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

[In the formula (II),
R ⁷ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
Ring ^{X 1} represents a heterocycle having 2 to 36 carbon atoms, a hydrogen atom contained in the heterocyclic ring, halogen atom, hydroxy group, a hydrocarbon group having 1 to 24 carbon atoms, an alkoxy group having 1 to 12 carbon atoms , May be substituted with an acyl group having 2 to 4 carbon atoms or an acyloxy group having 2 to 4 carbon atoms. ] 2. The resist resin according to claim 1, wherein the resist resin is decomposed by the action of an acid and has a property of reducing solubility in a solvent containing an organic solvent. The resist resin according to claim 2, wherein the organic solvent is butyl acetate or 2-heptanone. A resin having a first structural unit represented by formula (I), a second structural unit represented by formula (II), and a third structural unit containing an acid labile group,
The content ratio (molar ratio) of the first structural unit, the second structural unit, and the third structural unit is [content of first structural unit] / [content of second structural unit] / [third structural unit]. expressed in the content, [3-80] / [2 to 60] / [10-95] range der Ru tree fat.

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

[In the formula (II),
R ⁷ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
Ring ^{X 1} represents a heterocycle having 2 to 36 carbon atoms, a hydrogen atom contained in the heterocyclic ring, halogen atom, hydroxy group, a hydrocarbon group having 1 to 24 carbon atoms, an alkoxy group having 1 to 12 carbon atoms , May be substituted with an acyl group having 2 to 4 carbon atoms or an acyloxy group having 2 to 4 carbon atoms. ] A resin having a first structural unit represented by the formula (I), a second structural unit represented by the formula (II), a third structural unit containing an acid labile group, and an acid generator Resist composition.

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

[In the formula (II),
R ⁷ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
Ring ^{X 1} represents a heterocycle having 2 to 36 carbon atoms, a hydrogen atom contained in the heterocyclic ring, halogen atom, hydroxy group, a hydrocarbon group having 1 to 24 carbon atoms, an alkoxy group having 1 to 12 carbon atoms , May be substituted with an acyl group having 2 to 4 carbon atoms or an acyloxy group having 2 to 4 carbon atoms. ] The resist composition according to claim 5, wherein the acid generator is represented by formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, The methylene group constituting the hydrogen group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, a hydrogen atom or a fluorine atom, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A carbonyl group or a sulfonyl group may be substituted.
Z ⁺ represents an organic cation. ]   Furthermore, the resist composition of Claim 5 or 6 containing a solvent. (1) The process of apply | coating the resist composition of any one of Claims 5-7 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:

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