JP2013040319A - Resin, resist composition, and method for manufacturing resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition capable of manufacturing a resist pattern of an excellent mask error factor (MEF), and to provide a novel resin used for the same.SOLUTION: The resin has a structural unit (aa) represented by formula (aa) and a structural unit (ab) represented by formula (ab). The resist composition contains the resin and an acid generator. In the formula, Rand Rare a hydrogen atom or a methyl group; Ris a hydrogen atom or a fluoroalkyl group; Ris a fluoroalkyl group; Ris an acid stabilizing group; Ais a hydrocarbon group; Ais an alkanediyl group; and Ris an aliphatic hydrocarbon group.

Description

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

In recent years, as a semiconductor microfabrication technique, an optical lithography technique using short-wavelength light such as an ArF excimer laser (wavelength: 193 nm) as an exposure source has been actively studied. A resist composition is used in the optical lithography technology, and examples of the resin used in such a resist composition include a structural unit represented by the formula (u-A) and a formula (u-B). Resins composed of structural units are known. Further, the resin, a structural unit represented by the formula (u-C), a structural unit represented by the formula (u-D), a structural unit represented by the formula (u-E), and the formula (u-F) A resist composition containing a resin composed of a structural unit represented by (II) and an acid generator is also known (Patent Document 1).

JP 2009-191151 A

  A resist pattern produced from a conventionally known resist composition containing the above resin may not always satisfy the mask error factor (MEF).

［式（ａａ）中、
Ｒ^aa１は、水素原子又はメチル基を表す。
Ｒ^aa2は、水素原子又は炭素数１〜６のフッ化アルキル基を表す。
Ｒ^aa３は、炭素数１〜６のフッ化アルキル基を表す。
Ｒ^aa４は、酸の作用により、酸素原子との間の結合〔Ｏ−Ｒ^aa４〕が切断されない基を表す。
ｎ^aa１は１又は２を表す。ｎ^aa１が２の場合、２つのＲ^aa２は同一又は相異なり、２つのＲ^aa３は同一又は相異なり、２つのＲ^aa４は同一又は相異なる。
Ａ^aa１は、置換基を有していてもよい炭素数１〜１０の炭化水素基を表し、該炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］

［式（ａｂ）中、
Ｒ^ab1は、水素原子又はメチル基を表す。
Ａ^ab1は、置換基を有していてもよい炭素数１〜６のアルカンジイル基を表し、該アルカンジイル基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｒ^ab2は、置換基を有していてもよい炭素数１〜１８の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］
〔２〕前記式（ａｂ）のＡ^ａｂ１が、炭素数１〜６のアルカンジイル基である〔１〕記載の樹脂。
〔３〕前記式（ａｂ）のＡ^ａｂ１が、エチレン基である〔１〕記載の樹脂。
〔４〕前記式（ａｂ）で表される構造単位が、式（Ｉ）で表される構造単位である〔１〕〜〔３〕のいずれか記載の樹脂。

［式（Ｉ）中、
Ｒ^ab１及びＡ^ab１は、上記と同じ意味を表す。
Ａ¹⁵は、フッ素原子を有していてもよい炭素数１〜１５の２価の脂肪族炭化水素基表す。
Ｘ¹²は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ¹⁶は、フッ素原子を有していてもよい炭素数１〜１５の１価の脂肪族炭化水素基を表す。
ただし、Ａ¹⁵又はＡ¹⁶はフッ素原子を有し、Ａ¹⁵及びＡ¹⁶の炭素数の合計は１６以下である。］
〔５〕前記式（Ｉ）のＡ¹³が、炭素数１〜６のペルフルオロアルカンジイル基である〔４〕記載の樹脂。
〔６〕前記式（Ｉ）のＸ¹²が、＊−ＣＯ−Ｏ−（＊は、Ａ¹³との結合手を表す。）である〔４〕又は〔５〕記載の樹脂。
〔７〕前記式（Ｉ）のＡ¹⁴が、シクロヘキシル基、ノルボルニル基又はアダマンチル基である〔４〕〜〔６〕のいずれか記載の樹脂。
〔８〕〔１〕〜〔７〕のいずれか記載の樹脂と、酸発生剤とを含有するレジスト組成物。
〔９〕前記酸発生剤が、式（Ｂ１）で表される酸発生剤である〔８〕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、置換基を有していてもよい炭素数１〜１７の２価の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれるメチレン基は、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。］
〔１０〕前記式（Ｂ１）のＹが、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である〔９〕記載のレジスト組成物。
〔１１〕アルカリ水溶液に不溶又は難溶であり、酸の作用によりアルカリ水溶液に可溶となる樹脂を、さらに含有する〔８〕〜〔１０〕のいずれか記載のレジスト組成物。
〔１２〕（１）〔８〕〜〔１１〕のいずれか記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層を露光する工程、
（４）露光後の組成物層を加熱する工程及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A resin having a structural unit (aa) represented by the formula (aa) and a structural unit (ab) represented by the formula (ab).

[In the formula (aa)
R ^aa1 represents a hydrogen atom or a methyl group.
R ^aa2 represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
R ^aa3 represents a fluorinated alkyl group having 1 to 6 carbon atoms.
R ^aa4 represents a group in which the bond [O—R ^aa4 ] to the oxygen atom is not ^broken by the action of an acid.
n ^aa1 represents 1 or 2; When n ^aa1 is 2, two R ^aa2 are the same or different, two R ^aa3 are the same or different, and two R ^aa4 are the same or different.
A ^aa1 represents an ^optionally substituted hydrocarbon group having 1 to 10 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

[In the formula (ab),
R ^ab1 represents a hydrogen atom or a methyl group.
A ^ab1 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
R ^ab2 represents an ^optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. Good. ]
[2] The resin according to [1], wherein A ^{ab1 in the} formula (ab) is an alkanediyl group having 1 to 6 carbon atoms.
[3] The resin according to [1], wherein A ^{ab1 in the} formula (ab) is an ethylene group.
[4] The resin according to any one of [1] to [3], wherein the structural unit represented by the formula (ab) is a structural unit represented by the formula (I).

[In the formula (I),
R ^ab1 and A ^ab1 represent the same meaning as described above.
A ¹⁵ represents a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a fluorine atom.
X ¹² represents a carbonyloxy group or an oxycarbonyl group.
A ¹⁶ represents a monovalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a fluorine atom.
However, A ¹⁵ or A ¹⁶ has a fluorine atom, the total number of carbon atoms of A ¹⁵ and A ¹⁶ is 16 or less. ]
[5] The resin according to [4], wherein A ^{13 in the} formula (I) is a C 1-6 perfluoroalkanediyl group.
[6] The resin according to [4] or [5], wherein X ^{12 in the} formula (I) is * —CO—O— (* represents a bond to A ¹³ ).
[7] The resin according to any one of [4] to [6], wherein A ^{14 in the} formula (I) is a cyclohexyl group, a norbornyl group, or an adamantyl group.
[8] A resist composition comprising the resin according to any one of [1] to [7] and an acid generator.
[9] The resist composition according to [8], wherein the acid generator is an acid generator 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 C1-C17 divalent aliphatic hydrocarbon group which may have a substituent, and the methylene group contained in the aliphatic hydrocarbon group is replaced with an oxygen atom or a carbonyl group. It may be.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the aliphatic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group or a carbonyl group. May be.
Z ⁺ represents an organic cation. ]
[10] The resist composition according to [9], wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent.
[11] The resist composition according to any one of [8] to [10], further containing a resin that is insoluble or hardly soluble in an aqueous alkaline solution and becomes soluble in an aqueous alkaline solution by the action of an acid.
[12] (1) A step of applying the resist composition according to any one of [8] to [11] 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.

［式（Ｒ^４−１）中、
Ｒ⁴⁴、Ｒ⁴⁵及びＲ⁴⁶は、それぞれ独立に、炭素数１〜６の脂肪族飽和炭化水素基を表すか、Ｒ⁴⁴〜Ｒ⁴⁶のうちの２つが互いに結合して環を形成しており、残りの１つは水素原子又は炭素数１〜６の脂肪族飽和炭化水素基である。］ Furthermore, the present invention includes the following inventions.
[13] The resin according to [1], wherein R ^{aa4 in the} formula (aa) is a hydrogen atom.
[14] The resin according to [1], wherein R ^{aa4 in the} formula (aa) is an acyl group having 2 to 12 carbon atoms.
[15] The resin according to [1], wherein R ^{aa4 in the} formula (aa) is a group represented by the following formula (R ⁴ -1).

[In the formula (R ⁴ -1),
R ⁴⁴ , R ⁴⁵ and R ⁴⁶ each independently represents an aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, or two of R ^{44 to} R ⁴⁶ are bonded to each other to form a ring. The remaining one is a hydrogen atom or an aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms. ]

［式（Ｂ２−１）及び式（Ｂ２−２）中、
Ｂ^１は、単結合又は炭素数１〜６のアルカンジイル基を表し、該アルカンジイル基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ｌは、０〜５の整数を表す。
Ｒ^３は、炭素数１〜２０の炭化水素基を表し、該炭化水素基にメチレン基が含まれる場合、該メチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。ｌが２以上のとき、複数のＲ^３は同一又は相異なり、複数のＲ^３のうち、２つのＲ^３が互いに結合して、それらが結合する炭素原子とともに、炭素数３〜２０の環を形成していてもよい。
ｌ’は、０〜３の整数を表す。
Ｒ^４は、カルボキシ基、シアノ基又は炭素数１〜２０の炭化水素基を表し、該炭化水素基にメチレン基が含まれる場合、該メチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。ｌ’が２以上のとき、複数のＲ^４は同一又は相異なり、複数のＲ^４のうち、２つのＲ^４が互いに結合して、それらが結合する炭素原子とともに、炭素数３〜２０の環を形成していてもよい。］
〔１７〕前記式（ａａ）のＡ^aa1が、炭素数２〜１０の分岐鎖式炭化水素基又は炭素数３〜１０の脂環式炭化水素基である〔１〕及び〔１３〕〜〔１６〕記載の樹脂。 [16] The resin according to [1], wherein R ^{aa4 in the} formula (aa) is a group represented by the following formula (B2-1) or formula (B2-2).

[In Formula (B2-1) and Formula (B2-2),
B ¹ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
l represents an integer of 0 to 5.
R ³ represents a hydrocarbon group having 1 to 20 carbon atoms. When the hydrocarbon group includes a methylene group, the methylene group may be replaced with an oxygen atom or a carbonyl group. When l is 2 or more, the plurality of R ³ are the same or different, and among the plurality of R ³ , two R ³ are bonded to each other, and together with the carbon atom to which they are bonded, a ring having 3 to 20 carbon atoms It may be formed.
l ′ represents an integer of 0 to 3.
R ⁴ represents a carboxy group, a cyano group, or a hydrocarbon group having 1 to 20 carbon atoms. When the hydrocarbon group includes a methylene group, the methylene group may be replaced with an oxygen atom or a carbonyl group. . When l ′ is 2 or more, the plurality of R ⁴ are the same or different, and among the plurality of R ⁴ , two R ⁴ are bonded to each other, and together with the carbon atom to which they are bonded, a ring having 3 to 20 carbon atoms May be formed. ]
[17] ^{Aaa1 in the} formula (aa) is a branched hydrocarbon group having 2 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms [1] and [13] to [16 ] Resin of description.

  According to the resist composition containing the resin of the present invention, a resist pattern having an excellent mask error factor (MEF) can be produced.

  In the present specification, unless otherwise specified, the following examples of substituents are applied to any chemical structural formula having the same substituents while appropriately selecting the number of carbon atoms. Those which can be linear, branched or cyclic include any of them, and they may be mixed. When stereoisomers exist, all stereoisomers are included. * Represents a bond. In the following examples of substituents, the numerical value attached to “C” indicates the carbon number of each group.

  The “hydrocarbon group” includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group includes a chain and a cyclic, and further includes an aliphatic hydrocarbon group in which a chain and a cyclic aliphatic hydrocarbon group are combined.

Of the chain aliphatic hydrocarbon groups, monovalent ones typically include an alkyl group. Examples of the alkyl group include a methyl group (C ₁ ), an ethyl group (C ₂ ), a propyl group (C ₃ ), a butyl group (C ₄ ), a pentyl group (C ₅ ), a hexyl group (C ₆ ), a heptyl group ( C ₇ ), octyl group (C ₈ ), decyl group (C ₁₀ ), dodecyl group (C ₁₂ ), hexadecyl group (C ₁₄ ), pentadecyl group (C ₁₅ ), hexyldecyl group (C ₁₆ ), heptadecyl group ( C ₁₇₎ and octadecyl (C ₁₈₎ and the like, which may be in either linear or branched. Unless particularly limited, this chain hydrocarbon group may contain a carbon-carbon double bond in a part of the alkyl groups exemplified herein, but does not have such a carbon-carbon double bond. Saturated chain hydrocarbon groups, particularly saturated alkyl groups are preferred.
The divalent chain hydrocarbon group corresponds to an alkanediyl group obtained by removing one hydrogen atom from the alkyl group shown here.

多環式の脂環式炭化水素は、例えば、以下の式（ＫＡ−８）で示されるビシクロ〔２．２．１〕ヘプタン（以下「ノルボルナン」ということがある。）（Ｃ_７）、式（ＫＡ−９）で示されるアダマンタン（Ｃ₁₀）及び式（ＫＡ−１０）〜式（ＫＡ−２２）で示される脂環式炭化水素などが挙げられる。

２価の脂環式炭化水素基は、式（ＫＡ−１）〜式（ＫＡ−２２）の脂環式炭化水素から水素原子を２個取り去った基が該当する。 Of the cyclic aliphatic hydrocarbon groups (hereinafter sometimes referred to as “alicyclic hydrocarbon groups”), monovalent ones are typically groups obtained by removing one hydrogen atom from an alicyclic hydrocarbon. It is. The alicyclic hydrocarbon group may be an unsaturated alicyclic hydrocarbon group containing a carbon-carbon unsaturated bond, but is preferably a saturated alicyclic hydrocarbon group. The alicyclic hydrocarbon group may be monocyclic or polycyclic.
The monocyclic alicyclic hydrocarbon is typically a cycloalkane, and cyclopropane (C ₃ ) represented by the following formula (KA-1) and cyclobutane represented by the formula (KA-2) (C ₄ ), cyclopentane (C ₅ ) represented by formula (KA-3), cyclohexane (C ₆ ) represented by formula (KA-4), cycloheptane represented by formula (KA-5) (C ₇ ), cyclooctane (C ₈ ) represented by the formula (KA-6), cyclododecane (C ₁₂ ) represented by the formula (KA-7), and the like.

Examples of the polycyclic alicyclic hydrocarbon include bicyclo [2.2.1] heptane (hereinafter sometimes referred to as “norbornane”) represented by the following formula (KA-8) (C ₇ ), And adamantane (C ₁₀ ) represented by (KA-9) and alicyclic hydrocarbons represented by formula (KA-10) to formula (KA-22).

The divalent alicyclic hydrocarbon group corresponds to a group in which two hydrogen atoms have been removed from the alicyclic hydrocarbon of formula (KA-1) to formula (KA-22).

The aromatic hydrocarbon group is a monovalent aromatic hydrocarbon group and is typically an aryl group. Specific examples include a phenyl group (C ₆ ), a naphthyl group (C ₁₀ ), an anthryl group (C ₁₄ ), a biphenyl group (C ₁₂ ), a phenanthryl group (C ₁₄ ), and a fluorenyl group (C ₁₃ ). .

The aliphatic hydrocarbon group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group, an acyl group, an aryl group, an aralkyl group, and an aryloxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of alkoxy groups include methoxy group (C ₁ ), ethoxy group (C ₂ ), propoxy group (C ₃ ), butoxy group (C ₄ ), pentyloxy group (C ₅ ), hexyloxy group (C ₆ ), heptyl Examples thereof include an oxy group (C ₇ ), an octyloxy group (C ₈ ), a decyloxy group (C ₁₀ ), and a dodecyloxy group (C ₁₂ ). These alkoxy groups may be linear or branched.

Examples of the acyl group include acetyl group (C ₂ ), propionyl group (C ₃ ), butyryl group (C ₄ ), valeryl group (C ₅ ), hexanoyl group (C ₆ ), heptanoyl group (C ₇ ), octanoyl group ( C _8), decanoyl group (C ₁₀₎ and dodecanoyl groups (C ₁₂₎ which is an alkyl group and a carbonyl group, such as bonded, which aryl group and a carbonyl group such as benzoyl group (C ₇₎ is bonded Is mentioned. Among these acyl groups, an alkyl group and a carbonyl group bonded to each other may be linear or branched.

The aryl group is the same as that exemplified as the aryl group of the above-described aromatic hydrocarbon group, and the aryloxy group is a group in which an aryl group and an oxygen atom are bonded.
Examples of the aralkyl group include benzyl group (C ₇ ), phenethyl group (C ₈ ), phenylpropyl group (C ₉ ), naphthylmethyl group (C ₁₁ ), and naphthylethyl group (C ₁₂ ).
The aromatic hydrocarbon group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group, an acyl group, an alkyl group, and an aryloxy group. Examples of these substituents are the same as those described above.

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

<Resin>
The resin of the present invention has a structural unit (aa) represented by the formula (aa) and a structural unit (ab) represented by the formula (ab) (hereinafter sometimes referred to as “resin (X)”). ) New resin.

［式（ａａ）中、
Ｒ^aa１は、水素原子又はメチル基を表す。
Ｒ^aa2は、水素原子又は炭素数１〜６のフッ化アルキル基を表す。
Ｒ^aa３は、炭素数１〜６のフッ化アルキル基を表す。
Ｒ^aa４は、酸の作用により、酸素原子との結合〔Ｏ−Ｒ^aa４〕が切断されない基を表す。
ｎ^aa１は、１又は２を表す。ｎ^aa１が２の場合、２つのＲ^aa２は同一でも異なっていてもよく、２つのＲ^aa３は同一でも異なっていてもよく、２つのＲ^aa４は同一でも異なっていてもよい。
Ａ^aa１は、置換基を有していてもよい炭素数１〜１０の炭化水素基を表し、該炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ <Structural unit (aa)>
The structural unit (aa) is a structural unit represented by the formula (aa).

[In the formula (aa)
R ^aa1 represents a hydrogen atom or a methyl group.
R ^aa2 represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
R ^aa3 represents a fluorinated alkyl group having 1 to 6 carbon atoms.
R ^aa4 represents a group in which the bond [O—R ^aa4 ] to the oxygen atom is not ^broken by the action of an acid.
^naa1 represents 1 or 2. When n ^aa1 is 2, two R ^aa2 may be the same or different, two R ^aa3 may be the same or different, and two R ^aa4 may be the same or different.
A ^aa1 represents an ^optionally substituted hydrocarbon group having 1 to 10 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The hydrocarbon group of A ^aa1 may be any of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a combination of these, and the aliphatic hydrocarbon group may be a chain, a cyclic, or a combination of these. Any of the group hydrocarbon groups may be used. The aliphatic hydrocarbon group may have a carbon-carbon multiple bond in a part thereof, but is preferably a saturated aliphatic hydrocarbon group.

Ａ^aa1は、ｎ^aa1が２である場合、アルカンジイル基又は２価の脂環式炭化水素基から、さらに１つの水素原子を結合種にしたものが挙げられる。例えば、メチン基、エタン−１，１，１−トリイル基、エタン−１，１，２−トリイル基、プロパン−１，１，３−トリイル基、プロパン−１，２，３−トリイル基、シクロヘキサン−１，３，５−トリイル基及びアダマンタン−１，３，５−トリイル基などが挙げられる。 A ^aa1 is, when n ^aa1 is 1, an alkanediyl group or a divalent alicyclic hydrocarbon group.
As the alkanediyl group of A ^aa1 , a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group , A straight-chain alkanediyl group such as hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 -Branched alkanediyl groups such as a diyl group, 1-methylbutane-1,4-diyl group, 2-methylbutane-1,4-diyl group.
The divalent alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include those in which two hydrogen atoms are bonded from a cycloalkane such as cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, and cyclooctane. Is mentioned. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthalene, adamantane, norbornane and methylnorbornane, and those having two hydrogen atoms as a bond from the groups shown below.

A ^aa1 includes, when n ^aa1 is 2, an alkanediyl group or a divalent alicyclic hydrocarbon group in which one hydrogen atom is used as a bonding species. For example, methine group, ethane-1,1,1-triyl group, ethane-1,1,2-triyl group, propane-1,1,3-triyl group, propane-1,2,3-triyl group, cyclohexane -1,3,5-triyl group and adamantane-1,3,5-triyl group.

Examples of the group in which the methylene group contained in the hydrocarbon group of A ^aa1 is replaced with an oxygen atom or a carbonyl group, when ^naa1 is 1, include the following groups. * Represents a bond with a carbonyloxy group.

などが挙げられる。 As A ^aa1 when one or two of the methylene groups are replaced by oxygen atoms,

Etc.

などが挙げられる。 A ^aa1 when one or two of the methylene groups are replaced with a carbonyl group,

Etc.

などが挙げられる。 2 in turn, each of the methylene group, the preferably A ^aa1 when replaced by an oxygen atom and a carbonyl group, those containing a carbonyl group, its specific examples,

Etc.

などが挙げられる。 As A ^aa1 when three methylene groups are replaced by oxygen atoms and / or carbonyl groups,

Etc.

When n ^aa1 is 2, one in which one of the hydrogen atoms contained in the above-described group is replaced with a bond with C (R ^aa2 ) (R ^aa3 ) can be mentioned.
However, the methylene group adjacent to the oxygen atom to which A ^aa1 is bonded, that is, the methylene group at the bonding position with the oxygen atom is not replaced with the oxygen atom or the carbonyl group.

Examples of the substituent for the hydrocarbon group A ^aa1 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. However, the number of carbon atoms in this substituent is not included in the number of carbon atoms of A ^aa1 . In view of ease of production of the compound that derives the structural unit (aa) described later, a hydrocarbon group having no substituent is preferable as A ^aa1 .

Among these, A ^aa1 is preferably a branched chain hydrocarbon group having 2 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, such as 1-pentyl-1,2-ethylene group, cyclohexane-1 3,5-triyl group and adamantane-1,3,5-triyl group are more preferred. The chain hydrocarbon group is preferably an aliphatic saturated hydrocarbon group not containing a carbon-carbon multiple bond.

The fluorinated alkyl group of R ^aa2 and R ^aa3 refers to a group in which part or all of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms. Examples of the fluorinated alkyl group include difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1,1 , 2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoro Ethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4 , 4-octafluorobutyl group, 3- (trifluoromethyl) -2,2,3,4,4,4-hexafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoromethyl) -2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1, 2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4 , 5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and perfluorohexyl group, among others, trifluoromethyl group, perfluoroethyl group, 3- (trifluoromethyl) -2,2, 3, 4 4,4-hexafluoro-butyl group.
However, R ^aa2 and R ^aa3 are not both hydrogen atoms, and at least one is a fluorinated alkyl group.

In R ^aa4 , “the O—R ^aa4 bond is not cleaved by the action of an acid” means that in the resist composition described later, the O—R ^aa4 bond is not cleaved by an acid generated when the acid generator receives exposure energy. Means the characteristic. Hereinafter, such “cleaved by the action of an acid” is referred to as “having acid action characteristics”.
Examples of R ^aa4 include a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, and an acyl group having 2 to 20 carbon atoms.

When R ^aa4 is a hydrogen atom, the group represented by —O—R ^aa4 is a hydroxy group, and examples of the structural unit (aa) containing such a group include the following structural units.

In the structural unit (aa) represented by any one of the formulas (aa-1) to (aa-20), the structural unit in which the methyl group corresponding to R ^aa1 is replaced with a hydrogen atom is also the structural unit (aa). A specific example is given.
Among the specific examples of the structural unit (aa) when R ^aa4 is a hydrogen atom, the formula (aa-11), the formula (aa-12), the formula (aa-13), the formula (aa-14), the formula ( What is represented by either aa-15) or a formula (aa-19) is preferable.

（式（ａａ１）中の符号はいずれも、前記と同義である。）
化合物（ａａ１）は、例えば、特開２００８−１２２９３２号公報に記載の方法などの公知の方法により製造することができる。また、特開２００９−１９１１５１号公報に記載された化合物を用いてもよい。 The structural unit (aa) in which R ^aa4 is a hydrogen atom is derived from a compound represented by the following formula (aa1) (hereinafter sometimes referred to as “compound (aa1)”).

(All symbols in formula (aa1) have the same meanings as described above.)
Compound (aa1) can be produced, for example, by a known method such as the method described in JP-A-2008-122932. Moreover, you may use the compound described in Unexamined-Japanese-Patent No. 2009-191151.

式（ａａ−２１）〜式（ａａ−２５）のいずれかで表される構造単位（ａａ）において、Ｒ^aa１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、構造単位（ａａ）の具体例として挙げられる。 The hydrocarbon group exemplified as R ^aa4 is preferably an aliphatic hydrocarbon group, and more preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms. When the hydrocarbon group includes a methylene group, the methylene group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.
When R ^aa4 is an aliphatic hydrocarbon group, examples of the structural unit (aa) include the following structural units.

In the structural unit (aa) represented by any one of the formulas (aa-21) to (aa-25), the structural unit in which the methyl group corresponding to R ^aa1 is replaced with a hydrogen atom is also the structural unit (aa). A specific example is given.

［式（Ｒ^４−０）中、
Ｒ⁴¹は、置換基を有していてもよい炭素数１〜１９の炭化水素基を表す。］
アシル基としては、アセチル基、プロパノイル基、ブチリル基、イソブチリル基、ピバロイル基、シクロヘキサンカルボニル基及びアダマンタンカルボニル基等の脂肪族炭化水素基とカルボニル基とが連結したもの、ベンゾイル基のような芳香族基とカルボニル基とが連結したものが挙げられる。 The acyl group exemplified as R ^aa4 is more preferably one having 2 to 12 carbon atoms. The acyl group is typically represented by the following formula (R4-0).

Wherein ^(R 4 -0),
R ⁴¹ represents a C 1-19 hydrocarbon group which may have a substituent. ]
As the acyl group, an acetyl group, a propanoyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a cyclohexanecarbonyl group, an adamantanecarbonyl group, or other aliphatic hydrocarbon group and a carbonyl group, an aromatic group such as a benzoyl group And those in which a group and a carbonyl group are linked.

As acyl groups R ^aa4, R ⁴¹ of formula (R 4 ^-0) may be a group containing a lactone ring. The lactone ring is preferably a lactone ring having 4 to 18 carbon atoms, and more preferably a lactone ring having 4 to 12 carbon atoms. “The number of carbon atoms in the lactone ring” refers to the number of carbon atoms constituting the lactone ring.
The lactone ring includes a monocyclic lactone ring such as a γ-lactone ring and a δ-lactone ring, a γ-lactone ring, or a polycyclic lactone ring in which a δ-lactone ring is condensed with another alicyclic ring. Moreover, the hydrogen atom contained in the lactone ring may be substituted with a substituent. Preferred examples of the substituent include a carboxy group, a cyano group, and a methyl group. However, when the lactone ring has the substituent shown here, the total number of carbon atoms (carbon number) included in the substituent is included in the number of carbon atoms of the above lactone ring (carbon number of the ring atom). I can't.

［式（Ｂ２−１）、式（Ｂ２−２）、式（Ｂ２−３）中、
Ｂ^１は、単結合又は炭素数１〜６のアルカンジイル基を表し、該アルカンジイル基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。＊は結合手を表す。
ｌは、０〜５の整数を表し、
Ｒ^３は、炭素数１〜２０の炭化水素基を表し、該炭化水素基にメチレン基が含まれる場合、そのメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。ｌが２以上のとき、複数のＲ^３は同一又は相異なり、複数のＲ^３のうち、２つのＲ^３が互いに結合して、それらが結合する炭素原子とともに、炭素数３〜２０の環を形成していてもよい。
ｌ’は、０〜３の整数を表し、
Ｒ^４は、カルボキシ基、シアノ基又は炭素数１〜２０の炭化水素基を表し、該炭化水素基にメチレン基が含まれる場合、そのメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。ｌ’が２以上のとき、複数のＲ^４は同一又は相異なり、複数のＲ^４のうち、２つのＲ^４が互いに結合して、それらが結合する炭素原子とともに、炭素数３〜２０の環を形成していてもよい。
ｌ”は、０〜３の整数を表し、
Ｒ⁶は、カルボキシ基、シアノ基又は炭素数１〜２０の炭化水素基を表し、該炭化水素基にメチレン基が含まれる場合、そのメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。ｌ”が２以上のとき、複数のＲ⁶は同一又は相異なり、複数のＲ⁶のうち、２つのＲ⁶が互いに結合して、それらが結合する炭素原子とともに、炭素数３〜２０の環を形成していてもよい。］ Such R ^aa4 is, for example, a group represented by any one of the following formulas (B2-1), (B2-2), and (B2-3) [formula (B2-1) to formula (B2) -3)] and the like.

[In Formula (B2-1), Formula (B2-2), and Formula (B2-3),
B ¹ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxygen atom or a carbonyl group. * Represents a bond.
l represents an integer of 0 to 5;
R ³ represents a hydrocarbon group having 1 to 20 carbon atoms. When the hydrocarbon group includes a methylene group, the methylene group may be replaced with an oxygen atom or a carbonyl group. When l is 2 or more, the plurality of R ³ are the same or different, and among the plurality of R ³ , two R ³ are bonded to each other, and together with the carbon atom to which they are bonded, a ring having 3 to 20 carbon atoms It may be formed.
l ′ represents an integer of 0 to 3,
R ⁴ represents a carboxy group, a cyano group or a hydrocarbon group having 1 to 20 carbon atoms, and when the hydrocarbon group includes a methylene group, the methylene group may be replaced with an oxygen atom or a carbonyl group. . When l ′ is 2 or more, the plurality of R ⁴ are the same or different, and among the plurality of R ⁴ , two R ⁴ are bonded to each other, and together with the carbon atom to which they are bonded, a ring having 3 to 20 carbon atoms May be formed.
l ″ represents an integer of 0 to 3;
R ⁶ represents a carboxy group, a cyano group, or a hydrocarbon group having 1 to 20 carbon atoms. When the hydrocarbon group includes a methylene group, the methylene group may be replaced with an oxygen atom or a carbonyl group. . When l ″ is 2 or more, the plurality of R ⁶ are the same or different, and among the plurality of R ⁶ , two R ⁶ are bonded to each other, and together with the carbon atom to which they are bonded, a ring having 3 to 20 carbon atoms May be formed.]

Of the substituents (R ³ , R ⁴ and R ⁶ ) in the groups represented by the formulas (B2-1) to (B2-3), the hydrocarbon groups have already been exemplified in the above-mentioned range. Including things. The alkanediyl group of B ¹ includes those already exemplified in the range of 1 to 6 carbon atoms. The methylene group contained in the alkanediyl group is an oxygen atom (—O—, the oxygen atom may be represented by “—O—” in this specification) or a carbonyl group (—CO—, The carbonyl group may be represented by “—CO—” in the present specification.) Examples of the group replaced by * —O—CO—CH ₂ —O— and * —O—CO—CH ₂ — _{O-CO -, * - CH} 2 -O-CO- or _* -CH 2 -CO-O- and the like.
In Formula (B2-1), Formula (B2-2), and Formula (B2-3), B ¹ is preferably a single bond.

  Moreover, in group represented by Formula (B2-1)-Formula (B2-3), group represented by either of Formula (B2-1) and Formula (B2-2) is preferable.

［式（Ｒ^４−１）中、
Ｒ⁴⁴〜Ｒ⁴⁶は、それぞれ独立に、置換基を有していてもよい炭素数１〜６の脂肪族飽和炭化水素基を表すか、または、Ｒ⁴⁴〜Ｒ⁴⁶のうちの２つが互いに結合して環を形成していており、残りの１つは置換基を有していてもよい炭素数１〜６の脂肪族飽和炭化水素基又は水素原子である。］ The acyl group for R ^aa4 is more preferably a group represented by the following formula (R ⁴ -1).

[In the formula (R ⁴ -1),
R ^{44 to} R ⁴⁶ each independently represents an optionally substituted aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, or two of R ^{44 to} R ⁴⁶ are bonded to each other. The remaining one is an aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms or a hydrogen atom which may have a substituent. ]

Among the acyl groups represented by the formula (R ⁴ -1), as the acyl group when R ^{44 to} R ⁴⁶ are all aliphatic saturated hydrocarbon groups having 1 to 6 carbon atoms, a pivaloyl group or the like is preferable.

Two of R ^{44 to} R ⁴⁶ are bonded to each other to form a ring, and the remaining one is a hydrogen atom or an aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms. Examples thereof include a carbonyl group and an adamantylcarbonyl group. Furthermore, the group which the methylene group contained in the ring which this cyclohexyl carbonyl group and adamantyl carbonyl group have replaced the oxygen atom or the carbonyl group is mentioned.

When R ^aa4 is an acyl group, examples of the structural unit (aa) include the following structural units.

In the structural unit (aa) represented by any one of the formulas (aa-26) to (aa-66), the structural unit in which the methyl group corresponding to R ^aa1 is replaced with a hydrogen atom is also the structural unit (aa). A specific example is given.

［式（ａａａ）中、
Ｒ^aa11は、水素原子又はメチル基を表す。
Ｒ^aa12は、水素原子又は炭素数１〜６のフッ化アルキル基を表す。
Ｒ^aa13は、炭素数１〜６のフッ化アルキル基を表す。
Ｒ^aa14は、水素原子又は−ＣＯ−Ｒ^aa15を表す。
Ｒ^aa15は、炭素数１〜１０のアルキル基又は炭素数３〜１０の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
ｎ^aa11は、１又は２を表す。
Ａ^aa１は、炭素数１〜１０の炭化水素基を表す。］ The structural unit (aa) is preferably a structural unit (aaa).

[In the formula (aaa),
R ^aa11 represents a hydrogen atom or a methyl group.
R ^aa12 represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
R ^aa13 represents a fluorinated alkyl group having 1 to 6 carbon atoms.
R ^aa14 represents a hydrogen atom or —CO—R ^aa15 .
R ^aa15 represents an alkyl group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group is replaced with an oxygen atom or a carbonyl group. May be.
^naa11 represents 1 or 2.
A ^aa1 represents a hydrocarbon group having 1 to 10 carbon atoms. ]

R ^aa12 is preferably a hydrogen atom or a trifluoromethyl group.
R ^aa13 is preferably a trifluoromethyl group or a branched fluorinated alkyl group having 3 to 6 carbon atoms.
R ^aa14 is preferably —CO—R ^aa15 . When R ^aa14 is —CO—R ^aa15 , the resist pattern obtained from the resist composition tends to have fewer defects.
R ^aa15 preferably represents a branched alkyl group or an alicyclic hydrocarbon group having 3 to 6 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group is replaced with an oxygen atom or a carbonyl group. It may be.
A ^aa1 is preferably an alkanediyl group having 1 to 10 carbon atoms or a cycloalkanediyl group having 3 to 10 carbon atoms.

（式（ａａ２）中、
Ｒ^aa5は、炭素数１〜２０の炭化水素基又は炭素数２〜２０のアシル基を表す。その他の符号はいずれも、前記と同義である。） The structural unit (aa) in which R ^aa4 is a hydrocarbon group or an acyl group is derived from a compound represented by the following formula (aa2) (hereinafter sometimes referred to as “compound (aa2)”).

(In the formula (aa2),
R ^aa5 represents a hydrocarbon group having 1 to 20 carbon atoms or an acyl group having 2 to 20 carbon atoms. All other symbols are as defined above. )

反応剤であるカルボン酸（Ｒ^aa5−ＣＯＯＨ）は、Ｒ^aa5の種類に応じて、例えば市場から容易に入手できるものを選択することができ、公知の方法により製造したものを利用することができる。この反応は通常、溶媒の存在下で行われる。溶媒は、例えば、アセトニトリルなどである。なお、カルボニルジイミダゾールなどを触媒として用いることもできる。 Compound (aa2) can be easily produced from compound (aa1).

As the carboxylic acid (R ^aa5 —COOH) as the reactant, those easily available from the market, for example, can be selected according to the type of R ^aa5 , and those produced by known methods can be used. . This reaction is usually performed in the presence of a solvent. The solvent is, for example, acetonitrile. In addition, carbonyldiimidazole etc. can also be used as a catalyst.

［式（ａｂ）中、
Ｒ^ab1は、水素原子又はメチル基を表す。
Ａ^ab1は、置換基を有していてもよい炭素数１〜６のアルカンジイル基を表し、該アルカンジイル基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｒ^ab2は、置換基を有していてもよい炭素数１〜１８の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ <Structural unit (ab)>
The structural unit (ab) is a structural unit represented by the formula (ab).

[In the formula (ab),
R ^ab1 represents a hydrogen atom or a methyl group.
A ^ab1 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
R ^ab2 represents an ^optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. Good. ]

ただし、Ａ^ab1の両端の酸素原子と結合するメチレン基は、酸素原子又はカルボニル基に置き換わらないものが好ましい。 Examples of the alkanediyl group for A ^ab1 include those exemplified as the alkanediyl group for A ^aa1 .
As the substituent in A ^ab1 , a hydroxy group and an alkoxy group having 1 to 6 carbon atoms are preferable.
Examples of the group in which the methylene group contained in the alkanediyl group is replaced with an oxygen atom or a carbonyl group include the following groups (* represents a bond).

However, it is preferable that the methylene group bonded to the oxygen atoms at both ends of A ^ab1 does not replace the oxygen atom or the carbonyl group.

A ^ab1 is preferably an alkanediyl group having 1 to 6 carbon atoms, more preferably an alkanediyl group having 1 to 4 carbon atoms, still more preferably an alkanediyl group having 1 to 3 carbon atoms, An ethylene group is preferred.

The aliphatic hydrocarbon group for R ^ab2 may partially have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group (saturated hydrocarbon group). Preferred aliphatic hydrocarbon groups include linear or branched alkyl groups and alicyclic hydrocarbon groups.

また、これらアルキル基及び脂環式炭化水素を任意に組み合わせた基であってもよい。 Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl 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, a methylnorbornyl group, and the groups shown below.

Moreover, the group which combined these alkyl groups and alicyclic hydrocarbons arbitrarily may be sufficient.

The methylene group contained in the aliphatic hydrocarbon group of R ^ab2 may be replaced with at most about 2 oxygen atoms or carbonyl groups. Examples of such an aliphatic hydrocarbon group include the formulas (a-g2) described later. ) And the like.

（式（ａ−ｇ３）中、
Ｘ¹²は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ¹⁴は、ハロゲン原子（より好ましくは、フッ素原子）を有していてもよい炭素数１〜１５の１価の脂肪族炭化水素基を表す。）
Ｒ^ab２の脂肪族炭化水素基に式（ａ−ｇ３）で表される基が置換される場合、その数は、１又は複数であってもよいが、１であることが好ましい。 The aliphatic hydrocarbon group for R ^ab2 is preferably an aliphatic hydrocarbon group having a substituent.
As the substituent, a halogen atom (more preferably, a fluorine atom) or a group represented by the formula (a-g3) is preferable.

(In the formula (a-g3),
X ¹² represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁴ represents a monovalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a halogen atom (more preferably, a fluorine atom). )
^When the aliphatic hydrocarbon group represented by R ^ab2 is substituted with the group represented by the formula (a-g3), the number may be 1 or more, but 1 is preferable.

（式（ａ−ｇ２）中、
Ａ¹³は、ハロゲン原子（より好ましくは、フッ素原子）を有していてもよい炭素数１〜１５の２価の脂肪族炭化水素基表す。
Ｘ¹²は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ¹⁴は、ハロゲン原子（より好ましくは、フッ素原子）を有していてもよい炭素数１〜１５の１価の脂肪族炭化水素基を表す。
ただし、Ａ¹³又はＡ¹⁴はハロゲン原子（好ましくは、フッ素原子）を有し、Ａ¹³及びＡ¹⁴の炭素数の合計は１６以下である。） R ^ab2 is preferably a group having a halogen atom (more preferably a fluorine atom), more preferably an aliphatic hydrocarbon group having a halogen atom (more preferably a fluorine atom) or the following formula (a A group represented by -g2).

(In the formula (a-g2),
A ¹³ are members, a halogen atom (more preferably, fluorine atoms) represents a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a.
X ¹² represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁴ represents a monovalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a halogen atom (more preferably, a fluorine atom).
However, A ¹³ or A ¹⁴ is a halogen atom (preferably, fluorine atoms) has a total carbon number of A ¹³ and A ¹⁴ is 16 or less. )

The aliphatic hydrocarbon group for A ¹³ includes either a chain or a cyclic group, and a divalent aliphatic hydrocarbon group in which these are combined. The aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a halogen atom for A ¹³ (more preferably a fluorine atom) is preferably a saturated aliphatic hydrocarbon group which may have a fluorine atom.
Examples of the divalent aliphatic hydrocarbon group which may have a chain halogen atom (more preferably a fluorine atom) include a methylene group, a difluoromethylene group, an ethylene group, a trifluoroethylene group, a propanediyl group, Examples include perfluoropropanediyl group, butanediyl group, perfluorobutanediyl group, pentanediyl group and perfluoropentanediyl group.
The divalent aliphatic hydrocarbon group which may have a cyclic halogen atom (more preferably, a fluorine atom) may be monocyclic or polycyclic. Examples of the monocyclic aliphatic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent aliphatic hydrocarbon group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

The aliphatic hydrocarbon group for A ¹⁴ includes any of a chain and a cyclic group, and an aliphatic hydrocarbon group in which these are combined. The aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a halogen atom (more preferably a fluorine atom) for A ¹⁴ is preferably a saturated aliphatic hydrocarbon group which may have a fluorine atom.
Examples of the aliphatic hydrocarbon group which may have a chain halogen atom (more preferably a fluorine atom) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, 1,1,1- Trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1 , 2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,4,4-nonafluoropentyl group and pentyl group Hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group, perfluorooctyl group and the like.
The aliphatic hydrocarbon group which may have a cyclic halogen atom (more preferably, a fluorine atom) may be monocyclic or polycyclic. Examples of the monocyclic aliphatic hydrocarbon group include a cyclohexyl group and a perfluorocyclohexyl group. Examples of the polycyclic aliphatic hydrocarbon group include an adamantyl group, a norbornyl group, a perfluoroadamantyl group, and the like.

The aliphatic hydrocarbon group having a halogen atom (more preferably a fluorine atom) of R ^ab2 is preferably a saturated aliphatic hydrocarbon group having a halogen atom (more preferably a fluorine atom), more preferably , An aliphatic hydrocarbon group (for example, a perfluoroalkyl group or a perfluorocycloalkyl group) in which all of the hydrogen atoms are substituted with halogen atoms (more preferably, fluorine atoms). Further, a saturated chain aliphatic hydrocarbon group having a halogen atom (more preferably a fluorine atom) is preferable, and a perfluoroalkyl group is more preferable.
Examples of the chain aliphatic hydrocarbon group having a chain halogen atom (preferably a fluorine atom) include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, 2, 2,2-trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (Trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluoro Butyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trif Oroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4 , 4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6- Examples include dodecafluorohexyl group, perfluoropentylmethyl group, perfluorohexyl group, perfluoroheptyl group, perfluorooctyl group, trichloromethyl group, tribromomethyl group, and triiodomethyl group.

  Among them, preferred is a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group, and more preferably 1 to 6 carbon atoms. Perfluoroalkyl group, more preferably a C 1-3 perfluoroalkyl group.

［式（Ｉ）中、
Ｒ^ab１及びＡ^ab１は、上記と同じ意味を表す。
Ａ¹⁵は、フッ素原子を有していてもよい炭素数１〜１５の２価の脂肪族炭化水素基表す。
Ｘ¹²は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ¹⁶は、フッ素原子を有していてもよい炭素数１〜１５の１価の脂肪族炭化水素基を表す。
ただし、Ａ¹⁵又はＡ¹⁶はフッ素原子を有し、Ａ¹⁵及びＡ¹⁶の炭素数の合計は１６以下である。］ When R ^ab2 in formula (ab) has a group represented by formula (a-g3), a structural unit represented by formula (I) (hereinafter referred to as a structural unit represented by formula (ab)) “Structural unit (I)” may be preferred).

[In the formula (I),
R ^ab1 and A ^ab1 represent the same meaning as described above.
A ¹⁵ represents a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a fluorine atom.
X ¹² represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁶ represents a monovalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a fluorine atom.
However, A ¹⁵ or A ¹⁶ has a fluorine atom, the total number of carbon atoms of A ¹⁵ and A ¹⁶ is 16 or less. ]

In the formula (I), the divalent aliphatic hydrocarbon group which may have a fluorine atom of A ^{15 and} the monovalent aliphatic hydrocarbon group which may have a fluorine atom of A ¹⁶ are A It includes those similar to those exemplified in ¹³ and ^{a 14.}

In the formula (ab) and formula (I), the partial structures represented by * -A ¹³ -X ¹² -A ¹⁴ and * -A ¹⁵ -X ¹² -A ¹⁶ (* is a bond to a carbonyl group) The following structures are mentioned.

In addition, the aliphatic hydrocarbon group of A ¹³ and A ¹⁵ in the formula (ab) and the formula (I) preferably has 1 to 6 carbon atoms, more preferably 2 to 3 carbons. Groups are preferred. In particular, A ¹³ and A ¹⁵ are preferably an alkanediyl group having a fluorine atom, and more preferably a C 1-6 perfluoroalkanediyl group.
The aliphatic hydrocarbon group for A ¹⁴ and A ¹⁶ preferably has 6 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms.
Among them, A ¹⁴ and A ¹⁶ is preferably an alicyclic hydrocarbon group having 6 to 12 carbon atoms, a cyclohexyl group, norbornyl group and an adamantyl group are more preferred.
A ¹³ and A ¹⁴ and A ¹⁵ and A ¹⁶ may both have a fluorine atom, but A ¹³ and A ¹⁵ are aliphatic hydrocarbon groups having a fluorine atom, or A ¹⁴ and A ¹⁶ have a fluorine atom. The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group, and more preferably A ¹³ and A ¹⁵ are aliphatic hydrocarbon groups having a fluorine atom.
X ¹² is preferably * —CO—O— (* is a bond to A ¹³ or A ¹⁵ ).

Examples of the structural unit (ab) and the structural unit (I) include the following.

In the above structural unit, a structural unit in which the methyl group corresponding to R ^ab1 is replaced with a hydrogen atom can also be given as specific examples of the structural unit (ab) or the structural unit (I).

（式（ａｂ’）中の符号はいずれも、前記と同義である。） The structural unit (ab) is derived from a compound represented by the formula (ab ′) (hereinafter sometimes referred to as “compound (ab ′)”).

(All symbols in the formula (ab ′) have the same meanings as described above.)

溶媒としては、テトラヒドロフランなどが挙げられる。また、塩基性触媒としては、ピリジンなどが挙げられる。
式（ａｂｓ−１）で表される化合物としては、ヒドロキシエチルメタクリレートなどが挙げられ、市販品を利用することができる。また、例えば、（メタ）アクリル酸又はその誘導体（例えば、（メタ）アクリル酸クロリドなど）と、適当なジオール（ＨＯ−Ａ^ab１−ＯＨ）とを縮合する公知の方法によって得られたものを利用することができる。
式（ａｂｓ−２）で表される化合物としては、Ｒ^２の種類に応じて、対応するカルボン酸を無水物へと変換して用いることができる。市販品としては、ヘプタフルオロ酪酸無水物などがある。 Compound (ab ′) can be produced by the following methods (1) to (3).
(1) Compound (ab ′) is, for example, a reaction between a compound represented by the formula (abs-1) and a compound represented by the formula (abs-2) in a solvent in the presence of a basic catalyst. Can be manufactured.

Examples of the solvent include tetrahydrofuran. Examples of the basic catalyst include pyridine.
Examples of the compound represented by the formula (abs-1) include hydroxyethyl methacrylate, and a commercially available product can be used. In addition, for example, a product obtained by a known method of condensing (meth) acrylic acid or a derivative thereof (for example, (meth) acrylic acid chloride, etc.) and an appropriate diol (HO-A ^ab1- OH) is used. can do.
Examples of the compound represented by the formula (abs-2), depending on the type of R ^2, can be used to convert the corresponding carboxylic acid to the anhydride. Commercial products include heptafluorobutyric anhydride.

式（ａｂｓ−３）で表される化合物は、（メタ）アクリル酸クロリドであり、これは市場から容易に入手できる。式（ａｂｓ−３）で表される化合物の塩素原子を、臭素原子又はヨウ素原子に置き換えたものを利用してもよい。このような化合物は、例えば、（メタ）アクリル酸と、適当な臭素化剤又はヨウ素化剤とを反応させることで得ることができる。
式（ａｂｓ−４）で表される化合物は、Ｒ^ab2の種類に応じたカルボン酸（Ｒ^ab2−ＣＯＯＨ）又はその誘導体（例えば、Ｒ^ab2−ＣＯＣｌなど）と、適当なジオール（ＨＯ−Ａ^ab1−ＯＨ）とを縮合することによって得ることができる。
式（ａｂｓ−３）で表される化合物と、式（ａｂｓ−４）で表される化合物との反応の際には適当な脱酸剤（例えば、炭酸ナトリウムなど）を共存させることもできる。
溶媒としては、テトラヒドロフラン、メチルイソブチルケトン、トルエンなどが挙げられる。 (2) Further, for example, the compound (ab ′) includes a compound represented by the formula (abs-3) and a compound represented by the formula (abs-4) in the presence or absence of a solvent. It can be produced by reacting.

The compound represented by the formula (abs-3) is (meth) acrylic acid chloride, which can be easily obtained from the market. You may utilize what substituted the chlorine atom of the compound represented by Formula (abs-3) by the bromine atom or the iodine atom. Such a compound can be obtained, for example, by reacting (meth) acrylic acid with a suitable brominating agent or iodinating agent.
Wherein the compound represented by (abs-4) a carboxylic acid in accordance with the type of R ^ab2 (R ^ab2 -COOH) or a derivative thereof (eg, R, etc. ^ab2 -COCl) and a suitable diol (HO-A ^ab1 -OH).
In the reaction of the compound represented by the formula (abs-3) and the compound represented by the formula (abs-4), an appropriate deoxidizing agent (for example, sodium carbonate) can be allowed to coexist.
Examples of the solvent include tetrahydrofuran, methyl isobutyl ketone, toluene and the like.

溶媒としては、テトラヒドロフラン及びトルエンなどが用いられる。
また、反応の際には、公知のエステル化触媒（例えば、酸触媒やカルボジイミド触媒など）を共存させてもよい。
式（ａｂｓ−５）で表されるカルボン酸は、Ｒ^ab2の種類に応じて公知の方法により製造することができる。 (3) Furthermore, the compound (ab ′) is produced by reacting the compound represented by the formula (abs-1) with the carboxylic acid represented by the formula (abs-5) in the presence of a solvent. can do.

As the solvent, tetrahydrofuran, toluene and the like are used.
Moreover, you may coexist a well-known esterification catalyst (For example, an acid catalyst, a carbodiimide catalyst, etc.) in the case of reaction.
The carboxylic acid represented by the formula (abs-5) can be produced by a known method depending on the type of R ^ab2 .

［式（Ｉ’）中、Ｒ^ab1、Ａ^ab1、Ａ¹⁵、Ｘ¹²及びＡ¹⁶は、上記と同じ意味を表す。］ In particular, the structural unit (I) is derived from a compound represented by the formula (I ′) (hereinafter sometimes referred to as “compound (I ′)”).

[In the formula (I ′), R ^ab1 , A ^ab1 , A ¹⁵ , X ¹² and A ¹⁶ represent the same meaning as described above. ]

式（Ｉｓ−１）で表される化合物としては、市販品を用いてもよいし、公知の方法で製造して用いてもよい。ここでいう公知の方法とは、例えば、（メタ）アクリル酸又はその誘導体（例えば、（メタ）アクリル酸クロリドなど）と、適当なジオール（ＨＯ−Ａ^ab１−ＯＨ）とを縮合する方法が挙げられる。市販品としては、ヒドロキシエチルメタクリレートなどが挙げられる。 The compound represented by the formula (I ′) can be obtained, for example, by reacting the compound represented by the formula (Is-1) with the carboxylic acid represented by the formula (Is-2).
This reaction is usually performed in the presence of a solvent. As the solvent, tetrahydrofuran, toluene and the like are used. In the reaction, a known esterification catalyst (for example, an acid catalyst or a carbodiimide catalyst) may coexist.

As the compound represented by the formula (Is-1), a commercially available product may be used, or a compound produced by a known method may be used. Examples of the known method herein include a method of condensing (meth) acrylic acid or a derivative thereof (for example, (meth) acrylic acid chloride etc.) and an appropriate diol (HO-A ^ab1- OH). It is done. Examples of commercially available products include hydroxyethyl methacrylate.

The carboxylic acid represented by the formula (Is-2) can be produced by a known method. For example, any one of the following compounds may be used.

  In the resin (X), the structural unit (aa) and the structural unit (ab) may each be one kind, or only one or both may be plural kinds. Among these, the structural unit (aa) and the structural unit (ab) each preferably have one type in that the resin (X) can be easily produced. Examples of combinations of the structural unit (aa) and the structural unit (ab) are shown in Table 1 below. In Table 1, the structural unit (aa) represented by the formula (aa-1) is represented as “(aa-1)” according to the formula number, and similarly in the formula (ab-1) The represented structural unit (ab) or the like is expressed as “(ab-1)” or the like according to the formula number. For example, the notation “(aa-19) / (aa-41)” is represented by the structural unit (aa), the structural unit represented by the formula (aa-19), and the formula (aa-41). Together with a structural unit.

As long as the structural unit (aa) is such that the O—R ^aa4 bond is not cleaved by the action of an acid, the O—A ^aa1 bond may be cleaved.
Similarly, the ^{OA Ab1} bond contained in the structural unit (ab) may be cleaved by the action of an acid.
Such a structural unit having a bond that can be cleaved by the action of an acid (that is, having an acid action characteristic) contains a group unstable to the acid, and is insoluble or difficult to dissolve in an alkaline aqueous solution as described later. It is soluble and has the property of being soluble in an alkaline aqueous solution by the action of an acid.
Among them, it is preferable that both the ^{OA aa1} bond and the ^{OA ab1} bond are not cleaved by the action of an acid. By using a resin having such a structural unit (aa) and a structural unit (ab) for the resist composition, a resist pattern with better CD uniformity (CDU) can be produced.
In particular, the resin (X) preferably includes a structural unit that does not have a bond that can be cleaved by the action of an acid, that is, does not have acid action characteristics. For example, the resin (X) is preferably composed of only the structural unit (aa) and the structural unit (ab) (or the structural unit (I)). What consists only of the structural unit (aa) which does not have and structural unit (ab) is preferable.

  Moreover, resin (X) may have structural units other than structural unit (aa) and structural unit (ab) (or structural unit (I)). Examples of the structural unit other than the structural unit (aa) and the structural unit (ab) (or the structural unit (I)) include a structural unit that may be contained in the resin (A) described later.

The total content of the structural unit (aa) and the structural unit (ab) (or the structural unit (I)) is preferably 1 to 100 mol% with respect to all the structural units (100 mol%) of the resin (X). Yes, more preferably 5 to 100 mol%, still more preferably 10 to 100 mol%.
Content of structural unit (aa) and structural unit (ab) (or structural unit (I)) is 5-95 mol% with respect to all the structural units (100 mol%) of resin (X), respectively. More preferably, it is 10-90 mol%.
In the resin (X), the molar ratio of the structural unit (aa) and the structural unit (ab) (or the structural unit (I)) is preferably 1:99 to 99: 1, and 3:97 to 97. : 3 is preferable, and 50:50 to 95: 5 is more preferable.
The resin (X) having the structural unit (aa) and the structural unit (ab) (or the structural unit (I)) in such a content is a compound (aa It can manufacture by adjusting the usage-amount amount of ') and a compound (ab') (or compound (I ')).

<Resist composition>
The resist composition of the present invention contains a resin and an acid generator.
Any resin may be used as long as it contains the above-described resin (X). When the resin (X) is used for the resist composition, a resist pattern having excellent CD uniformity (CDU) can be produced with this resist composition.
Further, the resist composition of the present invention is preferably one that can form a better resist pattern due to a synergistic effect with the acid generator. Therefore, regardless of whether or not the resin (X) has a structural unit that does not have a bond that can be cleaved by the action of an acid as described above, a resin other than the resin (X), for example, an alkaline aqueous solution. It is preferable to include a resin that is insoluble or hardly soluble and has a property of being soluble in an alkaline aqueous solution by the action of an acid (hereinafter sometimes referred to as “resin (A)”).
The resist composition of the present invention preferably further contains a solvent and / or a basic compound.

<Resin (A)>
As described above, the resin (A) is a resin that is insoluble or hardly soluble in an alkaline aqueous solution and is soluble in an alkaline aqueous solution by the action of an acid. The resin (A) has one or more acid labile groups in the molecule. Hereinafter, the structural unit having an acid labile group may be referred to as “structural unit (a1)”.
Here, the “acid labile group” means a hydrophilic group protected by a protecting group that can be removed by contact with an acid, and examples of such a hydrophilic group include a hydroxy group or a carboxy group. It is done. Of these, a carboxy group is more preferable.
The resin (X) may have an acid labile group in addition to the structural unit (aa) (or the structural unit (I)) and the structural unit (ab).

式（１）中、Ｒ^a1〜Ｒ^a3は、それぞれ独立に、炭素数１〜８の脂肪族炭化水素基を表すか、Ｒ^a1及びＲ^a2が結合して、それらが結合する炭素原子とともに炭素数３〜２０の環を形成する。Ｒ^a1及びＲ^a2が結合して形成される環及び該脂肪族炭化水素基に含まれるメチレン基は、酸素原子、硫黄原子又はカルボニル基に置き換わっていてもよい。＊は結合手を表す。 <Acid labile group>
In the case where the hydrophilic group is a carboxy group, the acid labile group is such that the hydrogen atom of the carboxy group is replaced with an organic residue, and the atom of the organic residue bonded to —O— of the carboxy group is a tertiary carbon. Examples include groups that are atoms (ie, esters of tertiary alcohols). Among such acid labile groups, preferred acid labile groups are, for example, those represented by the following formula (1) (hereinafter sometimes referred to as “acid labile groups (1)”).

In the formula (1), R ^{a1 to} R ^a3 each independently represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, or R ^a1 and R ^a2 are bonded to each other and carbon together with the carbon atom to which they are bonded. A ring of several 3 to 20 is formed. The ring formed by combining R ^a1 and R ^a2 and the methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group. * Represents a bond.

The aliphatic hydrocarbon group for R ^{a1 to} R ^a3 is an alkyl group or an alicyclic hydrocarbon group.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
The alicyclic hydrocarbon group includes a monocyclic hydrocarbon group such as a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a decahydronaphthyl group, and an adamantyl group. , Norbornyl groups, methylnorbornyl groups, and polycyclic hydrocarbon groups such as the following groups.

The combination of R ^a1 and R ^a2 to form a ring means that the group represented by —C (R ^a1 ) (R ^a2 ) (R ^a3 ) is any of the followings. The number of carbon atoms in such a ring is preferably in the range of 3-12.

In Formula (1), the alicyclic hydrocarbon group of R ^{a1 to} R ^a3 preferably has 3 to 16 carbon atoms, and more preferably 3 to 16 carbon atoms.
Examples of the acid labile group represented by the formula (1) include:
1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are alkyl groups, preferably tert-butoxycarbonyl group),
2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and a carbon atom form an adamantyl group and R ^a3 is an alkyl group) and 1- (adamantane-1- Yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

式（２）中、Ｒ^b1及びＲ^b2は、それぞれ独立に、水素原子又は炭素数１〜２０の炭化水素基を表し、Ｒ^b3は、炭素数１〜２０の炭化水素基を表すか、或いは、Ｒ^b2及びＲ^b3が結合して、それらが各々結合する炭素原子及び酸素原子とともに炭素数３〜２０の環を形成する。該環又は該炭化水素基がメチレン基を含む場合、そのメチレン基は、酸素原子、硫黄原子又はカルボニル基に置き換わっていてもよく、Ｒ^b2及びＲ^b3が結合して形成される環に含まれるメチレン基も、酸素原子、硫黄原子又はカルボニル基に置き換わっていてもよい。＊は結合手を表す。 On the other hand, examples of the acid labile group in the case where the hydrophilic group is a hydroxy group include those in which a hydrogen atom of the hydroxy group is replaced with an organic residue to become a group containing an acetal structure or a ketal structure. Among such acid labile groups, preferred acid labile groups are, for example, those represented by the following formula (2) (hereinafter sometimes referred to as “acid labile groups (2)”).

In formula (2), R ^b1 and R ^b2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R ^b3 represents a hydrocarbon group having 1 to 20 carbon atoms, or , R ^b2 and R ^b3 are combined to form a ring having 3 to 20 carbon atoms together with the carbon atom and oxygen atom to which they are bonded. When the ring or the hydrocarbon group includes a methylene group, the methylene group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group, and is included in the ring formed by combining R ^b2 and R ^b3. The methylene group may also be replaced with an oxygen atom, a sulfur atom or a carbonyl group. * Represents a bond.

The hydrocarbon group of R ^{b1 to} R ^b3 may be any of the above-described alkyl group, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an aromatic hydrocarbon group.
^Examples of the ring formed by combining R ^b2 and R ^b3 include those in which one carbon atom of the ring formed by combining R ^a1 and R ^a2 described above is replaced with one oxygen atom.
Of R ^b1 and R ^b2 , at least one is preferably a hydrogen atom.

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

The structural unit (a1) is preferably derived from a monomer having an acid labile group and a carbon-carbon double bond, more preferably derived from a (meth) acrylic monomer having an acid labile group. .
The structural unit (a1) preferably has an acid labile group (1) or an acid labile group (2), and may have both of these acid labile groups. More preferred is the structural unit (a1) having an acid labile group (1).

  Among the structural units (a1) having an acid labile group (1), the acid labile group (1) is preferably an alicyclic hydrocarbon group having 5 to 20 carbon atoms. The resin (A) having the structural unit (a1) of such a sterically bulky group is a resist having a better resolution when a resist pattern is produced using the present resist composition containing the resin (A). Patterns can be manufactured.

式（ａ１−１）中、
Ｌ^a1は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−（ｋ１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。）で表される基を表す。
Ｒ^a4は、水素原子又はメチル基を表す。
Ｒ^a6は、炭素数１〜１０の脂肪族炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
式（ａ１−２）中、
Ｌ^a2は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−（ｋ１は前記と同義である。
）で表される基を表す。
Ｒ^a5は、水素原子又はメチル基を表す。
Ｒ^a7は、炭素数１〜１０の脂肪族炭化水素基を表す。
ｎ１は０〜１０の整数を表す。
ｎ１’は０〜３の整数を表す。 Among the structural units (a1) having an acid labile group (1) having a partial structure of an alicyclic hydrocarbon group, a structural unit represented by the formula (a1-1) (hereinafter, “structural unit (a1 -1) ") and the structural unit represented by the formula (a1-2) (hereinafter sometimes referred to as" structural unit (a1-2) ").

In formula (a1-1),
L ^a1 represents 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 bond to a carbonyl group). Represent.
R ^a4 represents a hydrogen atom or a methyl group.
R ^a6 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
m1 represents the integer of 0-14.
In formula (a1-2),
L ^a2 is an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O— (k1 is as defined above).
) Represents a group represented by
R ^a5 represents a hydrogen atom or a methyl group.
R ^a7 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3.

L ^a1 and L ^a2 are preferably an oxygen atom or a group represented by * —O— (CH ₂ ) _k1 —CO—O—, 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.
Of the aliphatic hydrocarbon groups of R ^a6 and R ^a7 , preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and within the range of the upper limit of the carbon number, Includes the same as those already exemplified. The aliphatic hydrocarbon groups for R ^a6 and R ^a7 are each independently preferably an alkyl group having 8 or less carbon atoms or an alicyclic hydrocarbon group having 8 or less carbon atoms, more preferably an alkyl group having 6 or less carbon atoms. Or it is an alicyclic hydrocarbon group having 6 or less carbon atoms.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

Here, specific examples of the structural unit (a1-1) are given.

上記の構造単位において、Ｒ^a4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、構造単位（ａ１−１）の具体例として挙げることができる。

In the structural unit, a structural unit in which a methyl group corresponding to R ^a4 is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a1-1).

Among them, the structural unit represented by any one of formula (a1-1-1), formula (a1-1-2) and formula (a1-1-3), and methyl corresponding to R ^a4 of these structural units A structural unit in which a group is replaced with a hydrogen atom is preferable, and a structural unit represented by any one of formula (a1-1-1), formula (a1-1-2) and formula (a1-1-3) (a1- 1) is more preferable, and the structural unit represented by either formula (a1-1-1) or formula (a1-1-2) is more preferable.
When the resin (A) having these preferred structural units (a1-1) is used to produce the resin (A), 2-methyladamantan-2-yl (meth) acrylate, 2-ethyladamantan-2-yl (meta) ) Acrylate or 2-isopropyladamantan-2-yl (meth) acrylate or the like may be used as a raw material (monomer) for production.

上記の構造単位において、Ｒ^a5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、構造単位（ａ１−１）の具体例として挙げることができる。 Specific examples of the structural unit (a1-2) are shown below.

In the above structural unit, a structural unit in which a methyl group corresponding to R ^a5 is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a1-1).

Among them, the structural unit (a1-2-1), the formula (a1-2-2), the formula (a1-2-4), and the formula (a1-2-5) represented by any one of the formulas (a1-2-1), (a1-2-2), (a1-2-5) 2), or a structural unit in which a methyl group corresponding to R ^a5 in these structural units (a1-2) is replaced with a hydrogen atom is more preferable, and is represented by formulas (a1-2-4) and (a1-2-5) Or a structural unit in which a methyl group corresponding to R ^a5 in these structural units (a1-2) is replaced with a hydrogen atom. In order to produce the resin (A) having such a structural unit (a1-2), 1-ethylcyclohexane-1-yl (meth) acrylate or the like may be used as a monomer.

When the resin (A) having the structural unit (a1-1) and / or the structural unit (a1-2) is produced, when the total structural unit of the resin (A) is 100 mol%, the structural unit (a1-1) ) And / or the total content of the structural unit (a1-2) is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%, and still more preferably in the range of 20 to 85 mol%.
When resin (X) has a structural unit (a1-1) and / or a structural unit (a1-2), the total content is 5 with respect to all the structural units (100 mol%) of resin (X). The range of -50 mol% is preferable, the range of 10-45 mol% is more preferable, and the range of 15-40 mol% is further more preferable.
In order to make the total content of the structural unit (a1-1) and / or the structural unit (a1-2) in such a range, when the resin (A) is produced, What is necessary is just to adjust the usage-amount of the monomer which induces | guides | derives a structural unit (a1-1) and / or a structural unit (a1-2).
When producing the resin (X) having the structural unit (a1-1) and / or the structural unit (a1-2), the structural unit (a1-1) and / or the structural unit (a1-2) is derived. What is necessary is just to adjust the ratio of the usage-amount of a monomer, and the usage-amount of a compound (aa1) and / or a compound (aa2), or a compound (ab ').

式（ａ１−３）中、
Ｒ^a9は、水素原子、ヒドロキシ基を有していてもよい炭素数１〜３のアルキル基、カルボキシ基、シアノ基又は−ＣＯＯＲ^a13（Ｒ^a13は、炭素数１〜２０の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子は、ヒドロキシ基に置換されていてもよく、該脂肪族炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。）を表す。
Ｒ^a10〜Ｒ^a12は、それぞれ独立に、炭素数１〜２０の脂肪族炭化水素基を表すか、或いは、Ｒ^a10及びＲ^a11が結合して、これらが結合している炭素原子とともに、炭素数３〜２０の環を形成する。なお、この脂肪族炭化水素基に含まれる水素原子は、ヒドロキシ基などに置換されていてもよく、該脂肪族炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。 Examples of the structural unit (a1) include those derived from a monomer having a norbornene ring represented by the following formula (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”).

In formula (a1-3),
R ^a9 is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms that may have a hydroxy group, a carboxy group, a cyano group, or —COOR ^a13 (R ^a13 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms. Wherein a hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group, and a methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. .)
R ^{a10 to} R ^a12 each independently represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or R ^a10 and R ^a11 are bonded to each other together with the carbon atom to which these are bonded, 3-20 rings are formed. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and the methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. .

As for the alkyl group which has a hydroxyl group of ^Ra9, a hydroxymethyl group, 2-hydroxyethyl group, etc. are mentioned, for example.
R ^a13 in groups -COOR ^a13 is preferably an alicyclic hydrocarbon group of the alkyl group or 3 to 20 carbon atoms having 1 to 8 carbon atoms.
The aliphatic hydrocarbon group for R ^{a10 to} R ^a12 may be a chain hydrocarbon group (for example, an alkyl group) or an alicyclic hydrocarbon group.
The ring formed by combining R ^a10 and R ^a11 is preferably an aliphatic hydrocarbon ring, and specifically, a cyclohexane ring and an adamantane ring are more preferable.

^Examples of R ^a9 —COOR ^a13 include groups in which a carbonyl group is further bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.

  As the monomer (a1-3), 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl Cyclohexyl, 2-norbornene-2-carboxylic acid 2-methyl-adamantan-2-yl, 5-norbornene-2-carboxylic acid 2-ethyl-adamantan-2-yl, 5-norbornene-2-carboxylic acid 1- (4 -Methyl-cyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4- Oxocyclohexyl) ethyl and 1- (adamantan-1-yl) 5-norbornene-2-carboxylate -1-methylethyl and the like.

  When the resin (A) is produced using the monomer (a1-3), the resin (A) includes a sterically bulky structural unit derived from the monomer (a1-3). Thus, if a resist pattern is manufactured with this resist composition containing resin (A) which has a three-dimensionally bulky structural unit, a resist pattern can be obtained with a better resolution. Furthermore, since a rigid norbornane ring can be introduced into the main chain of the resin (A) by using the monomer (a1-3), this resist composition containing the resin (A) is a resist excellent in dry etching resistance. There is a tendency that a pattern is easily obtained.

The monomer (a1-3) with respect to the total structural unit (100 mol%) of the resin (A) is advantageous in that a resist pattern can be produced with good resolution and a resist pattern excellent in dry etching resistance can be obtained. The content of the derived structural unit is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%, and still more preferably in the range of 20 to 85 mol%.
When the resin (X) has a structural unit derived from the monomer (a1-3), the content thereof is in the range of 5 to 50 mol% with respect to the total structural unit (100 mol%) of the resin (X). Is preferable, the range of 10-45 mol% is more preferable, and the range of 15-40 mol% is further more preferable.

式（ａ１−４）中、
Ｒ^a32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（ハロアルキル基）、水素原子又はハロゲン原子を表す。
Ｒ^a33は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｌａは０〜４の整数を表す。ｌａが２以上である場合、複数のＲ^a33は同一又は相異なる。
Ｒ^a34及びＲ^a35はそれぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｘ^a2は、単結合又は炭素数１〜１７の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基及び炭素数２〜４のアシルオキシ基からなる群より選ばれる基に置換されていてもよい。該脂肪族炭化水素基に含まれるメチレン基は、酸素原子、硫黄原子、カルボニル基、スルホニル基又は−Ｎ（Ｒ^ｃ）−で示される基に置き換わっていてもよい。Ｒ^cは、水素原子又は炭素数１〜６のアルキル基を表す。
Ｙ^a3は、炭素数１〜１８の炭化水素基であり、さらに好ましくは、炭素数３〜１８の脂環式炭化水素基又は炭素数６〜１８の芳香族炭化水素基であり、これらの炭化水素基は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基を有していてもよい。 Examples of the monomer having an acid labile group (2) include a monomer represented by the following formula (a1-4) (hereinafter sometimes referred to as “monomer (a1-4)”).

In formula (a1-4),
R ^a32 represents a C 1-6 alkyl group (haloalkyl group), a hydrogen atom or a halogen atom which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group, or methacryloyl. Represents a group.
la represents an integer of 0 to 4. When la is 2 or more, the plurality of R ^a33 are the same or different.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
X ^a2 represents a single bond or an aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the aliphatic hydrocarbon group is a halogen atom, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, carbon It may be substituted with a group selected from the group consisting of an acyl group having 2 to 4 carbon atoms and an acyloxy group having 2 to 4 carbon atoms. The methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or a group represented by —N (R ^c ) —. R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y ^a3 is a hydrocarbon group having 1 to 18 carbon atoms, and more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen group has a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms. Also good.

Examples of the haloalkyl group for R ^a32 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. , Trichloromethyl group, tribromomethyl group, triiodomethyl group and the like.
The alkyl group for R ^a32 and R ^a33 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.
As the alkoxy group for R ^a33 , a methoxy group or an ethoxy group is more preferable, and a methoxy group is particularly preferable.
Hydrocarbon group R ^a34 and R ^a35 are chain hydrocarbon groups may be either an alicyclic hydrocarbon group and aromatic hydrocarbon group. Among these, as the chain hydrocarbon group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group are preferable, and alicyclic hydrocarbons. As the group, a cyclohexyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, and an isobornyl group are preferable. As an aromatic hydrocarbon group, a phenyl group Naphthyl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl, anthryl, phenanthryl, 2,6-diethyl A phenyl group and 2-methyl-6-ethylphenyl are preferred.

The aliphatic hydrocarbon group for X ^a2 is preferably a chain hydrocarbon group, and more preferably an alkyl group.
Y ^a3 is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The substituent for X ^a2 and Y ^a3 is preferably a hydroxy group.

Examples of the monomer (a1-4) include the following monomers.

上記モノマーにおいて、Ｒ^a32に相当する水素原子がメチル基に置き換わったモノマーも、モノマー（ａ１−４）の具体例として挙げることができる。

In the above monomer, a monomer in which a hydrogen atom corresponding to R ^a32 is replaced with a methyl group can also be mentioned as a specific example of the monomer (a1-4).

When the resin (A) has a structural unit derived from the monomer (a1-4), the content thereof is in the range of 10 to 95 mol% with respect to all the structural units (100 mol%) of the resin (A). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.
When the resin (X) has a structural unit derived from the monomer (a1-4), the content thereof is in the range of 5 to 50 mol% with respect to the total structural unit (100 mol%) of the resin (X). Is preferable, the range of 10-45 mol% is more preferable, and the range of 15-40 mol% is further more preferable.

式（ａ１−５）中、
Ｒ^３１は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｌ^１〜Ｌ^３は、酸素原子又は硫黄原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−で表される基を表す。ここで、ｋ１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に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ｓ１及びｓ１’は、それぞれ独立して、０〜４の整数を表す。 As the monomer having an acid labile group (2), for example, a monomer represented by the formula (a1-5) (hereinafter sometimes referred to as “monomer (a1-5)”) may also be used.

In formula (a1-5),
R ³¹ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
L ^{1 to} L ³ represent an oxygen atom, a sulfur atom, or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O—. Here, k1 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 contained in the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
s1 and s1 ′ each independently represents an integer of 0 to 4.

In formula (a1-5), R ³¹ is preferably a hydrogen atom or a methyl 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.

上記モノマーにおいて、Ｒ³¹に相当するメチル基が水素原子に置き換わったモノマーも、モノマー（ａ１−５）の具体例として挙げることができる。

In the above monomer, a monomer in which the methyl group corresponding to R ³¹ is replaced with a hydrogen atom can also be mentioned as a specific example of the monomer (a1-5).

When the resin (A) has a structural unit derived from the monomer (a1-5), the content thereof is in the range of 10 to 95 mol% with respect to all the structural units (100 mol%) of the resin (A). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.
When the resin (X) has a structural unit derived from the monomer (a1-5), the content thereof is in the range of 5 to 50 mol% with respect to all the structural units (100 mol%) of the resin (X). Is preferable, the range of 10-45 mol% is more preferable, and the range of 15-40 mol% is further more preferable.

As the structural unit (a1) having an acid labile group (1) and a carbon-carbon double bond in the molecule, structural units derived from the following monomers can be used.

When manufacturing resin (A) using the monomer mentioned above, 10-95 mol% is preferable with respect to all the structural units (100 mol%) of resin (A), 15-90 mol% is preferable. More preferably, 20-85 mol% is further more preferable.
When the resin (X) has a structural unit derived from the above-described monomer, the content thereof is preferably in the range of 5 to 50 mol% with respect to the total structural unit (100 mol%) of the resin (X). The range of 10-45 mol% is more preferable, and the range of 15-40 mol% is further more preferable.

<Acid stable structural unit>
The resin (A) preferably has a structural unit having no acid labile group (hereinafter, sometimes referred to as “acid stable structural unit”) in addition to the acid labile structural unit (a1). .
The resin (X) may have an acid stable structural unit in addition to the structural unit (aa) (or the structural unit (I)) and the structural unit (ab). The acid stable structural unit can be introduced into the resin (A) by copolymerization using a monomer having no acid stable group.

  The acid stable structural unit is preferably a structural unit having a hydroxy group or a lactone ring. An acid stable structural unit having a hydroxy group (hereinafter sometimes referred to as “acid stable structural unit (a2)”) and / or an acid stable structural unit having a lactone ring (hereinafter referred to as “acid stable structural unit (a3)”). In some cases, the resolution of the resist and the adhesion of the resist pattern to the substrate can be improved.

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

式（ａ２−０）中、
Ｒ^a30は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^a31は同一又は相異なる。 <Acid stable structural unit (a2-0)>
Examples of the acid stable structural unit (a2) include those represented by the following formula (a2-0) (hereinafter sometimes referred to as “acid stable structural unit (a2-0)”).

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

Alkyl group and a halogen atom which may 1 to 6 carbon atoms having a halogen atom of R ^a30 are the same as those exemplified in R ^a32 of formula (a1-4). Among these, R ^a30 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.
As the alkyl group for R ^a31 , an alkyl group having 1 to 4 carbon atoms is preferable, an alkyl group having 1 or 2 carbon atoms is more preferable, and a methyl group is particularly preferable.
The alkoxy group for R ^a31 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and particularly preferably a methoxy group.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.

上記のモノマーにおいて、ベンゼン環に結合しているメチル基、エチル基等を、Ｒ^a31として例示したその他の置換基に置き換えたものも、酸安定モノマー（ａ２−０）の具体例として挙げることができる。 Examples of the monomer for deriving the acid stable structural unit (a2-0) include the following.

In the above monomers, those in which the methyl group, ethyl group, etc. bonded to the benzene ring are replaced with other substituents exemplified as R ^a31 may be mentioned as specific examples of the acid stable monomer (a2-0). it can.

  When the resin (A) is produced using the acid stable monomer (a2-0), a monomer in which the phenolic hydroxy group in the acid stable monomer (a2-0) is protected with a protecting group can also be used. As the protecting group, for example, a protecting group capable of leaving with an acid or a base is preferable. A phenolic hydroxy group protected with a protecting group capable of leaving with an acid or a base can be deprotected by contact with an acid or a base. However, since the resin (A) has a structural unit (a1) containing an acid labile group, when the phenolic hydroxy group protected with a protecting group is deprotected, the structural unit (a1) Deprotection by contact with a base is preferred so that the acid labile group is not significantly impaired. As the protective group, for example, an acetyl group, a benzoyl group and the like are preferable. Examples of the base include 4-dimethylaminoviridine, triethylamine and the like.

  Of these, 4-hydroxystyrene or 4-hydroxy-α-methylstyrene is particularly preferable. As these compounds, those obtained by protecting a phenolic hydroxy group with an appropriate protecting group can also be used.

When resin (A) has an acid stable structural unit (a2-0), the content is preferably in the range of 5 to 95 mol% with respect to all structural units (100 mol%) of resin (A). The range of 10-80 mol% is more preferable, and the range of 15-80 mol% is more preferable.
When the resin (X) has an acid stable structural unit (a2-0), the content is preferably 5 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (X). The range of -80 mol% is more preferable, and the range of 15-80 mol% is more preferable.

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

In formula (a2-1),
L ^a3 represents an oxygen atom or ^* —O— (CH ₂ ) _k2 —CO—O— (k2 represents an integer of 1 to 7), and * represents a bond with a carbonyl group (—CO—). Represent.
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.

上記の構造単位において、Ｒ^a14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、構造単位（ａ２−１）の具体例として挙げることができる。

In the above structural unit, a structural unit in which a methyl group corresponding to R ^a14 is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a2-1).

Among them, an acid stable structural unit represented by any one of formula (a2-1-1), formula (a2-1-2), formula (a2-1-13) and formula (a2-1-15) ( a2-1) and structural units in which the methyl group corresponding to R ^a14 of these acid stable structural units (a2-1) is replaced by a hydrogen atom are preferred, and are represented by formulas (a2-1-1) and (a2-1-1- 2) The acid stable structural unit represented by any one of formula (a2-1-13) and formula (a2-1-15) is more preferred.
Resin (A) which has these acid stable structural units (a2-1) is 3-hydroxyadamantan-1-yl (meth) acrylate, 3,5-dihydroxyadamantan-1-yl (meth) acrylate or (meth) What is necessary is just to use acrylic acid 1- (3,5-dihydroxyadamantane-1-yloxycarbonyl) methyl etc. as a monomer for resin (A) manufacture.

When the resin (A) has an acid stable structural unit (a2-1), the content thereof is preferably in the range of 3 to 45 mol% with respect to all the structural units (100 mol%) of the resin (A). The range of 5-40 mol% is more preferable, and the range of 5-35 mol% is more preferable.
When the resin (X) has an acid stable structural unit (a2-1), the content thereof is preferably in the range of 3 to 45 mol% with respect to all the structural units (100 mol%) of the resin (X). The range of 5-40 mol% is more preferable, and the range of 5-35 mol% is more preferable.

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

［式（ａ３−１）中、
Ｌ^a4は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）を表す。＊はカルボニル基との結合手を表す。
Ｒ^a18は、水素原子又はメチル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a21は炭素数１〜４の脂肪族炭化水素基を表し、ｐ１が２以上の場合、複数のＲ^a21は同一又は相異なる。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）を表す。＊はカルボニル基との結合手を表す。
ｑ１は、０〜３の整数を表す。
Ｒ^a22は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表し、ｑ１が２以上の場合、複数のＲ^a22は同一又は相異なる。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）を表す。＊はカルボニル基との結合手を表す。
Ｒ^a20は、水素原子又はメチル基を表す。
ｒ１は、０〜３の整数を表す。
Ｒ^a23は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表し、ｒ１が２以上の場合、複数のＲ^a23は同一又は相異なる。］ The acid stable structural unit (a3) is preferably one represented by the following formula (a3-1), formula (a3-2) or formula (a3-3). Resin (A) may have only 1 type among these, and may have 2 or more types. In the following description, what is represented by the formula (a3-1) is referred to as “acid-stable structural unit (a3-1)”, and what is represented by the formula (a3-2) is “acid-stable structural unit ( a3-2) ”, and the compound represented by formula (a3-3) may be referred to as“ acid-stable structural unit (a3-3) ”.

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

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

Examples of the acid stable structural unit (a3-1) having a γ-butyrolactone ring include the following.

Examples of the acid stable structural unit (a3-2) having a condensed ring of γ-butyrolactone ring and norbornane ring include the following.

上記の構造単位において、Ｒ^a18〜Ｒ^a20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、各々酸安定構造単位（ａ３−１）、酸安定構造単位（ａ３−２）及び酸安定構造単位（ａ３−３）の具体例として挙げることができる。また、この例示において、ラクトン環が有する置換基（Ｒ^a21〜Ｒ^a23）としてメチル基を有するものも例示したが、このメチル基を上述のような基に置き換えたものも、酸安定構造単位（ａ３）の具体例として挙げられる。 Examples of the acid stable structural unit (a3-3) having a condensed ring of γ-butyrolactone ring and cyclohexane ring include the following.

In the above structural units, the structural units in which the methyl groups corresponding to R ^{a18 to} R ^a20 are replaced by hydrogen atoms are the acid stable structural unit (a3-1), the acid stable structural unit (a3-2), and the acid stable structural unit, respectively. It can be mentioned as a specific example of (a3-3). Moreover, in this illustration, those having a methyl group as an example of the substituent (R ^{a21 to} R ^a23 ) of the lactone ring are also exemplified, but those in which this methyl group is replaced with the above-described groups are also acid stable structural units ( Specific examples of a3) are mentioned.

Among the acid stable structural units (a3), α- (meth) acryloyloxy-γ-butyrolactone, β- (meth) acryloyloxy-γ-butyrolactone, α- (meth) acryloyloxy-β, β-dimethyl-γ-butyrolactone, α -(Meth) acryloyloxy-α-methyl-γ-butyrolactone, β- (meth) acryloyloxy-α-methyl-γ-butyrolactone, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1 .0 ^3,7] nonane-2-yl, (meth) acrylic acid 2- tetrahydro-2-oxo-3-furyl, and (meth) acrylic acid (5-oxo-4-oxa-tricyclo [4.2.1 .0 ^3,7] nonane-2-yloxy) -2-oxoethyl acid derived from such stable structural unit (a3) is preferable.

The resin (A) has an acid stable structural unit (a3) selected from the group consisting of an acid stable structural unit (a3-1), an acid stable structural unit (a3-2), and an acid stable structural unit (a3-3). In this case, the total content is preferably in the range of 5 to 70 mol%, more preferably in the range of 10 to 65 mol%, and more preferably 10 to 60 mol, based on the total structural unit (100 mol%) of the resin (A). % Range is more preferred. The content of each of the acid stable structural unit (a3-1), the acid stable structural unit (a3-2) and the acid stable structural unit (a3-3) is the total structural unit (100 mol%) of the resin (A2). On the other hand, the range of 5-60 mol% is preferable, the range of 10-55 mol% is more preferable, the range of 20-50 mol% is more preferable, and the range of 20-45 mol% is still more preferable.
The resin (X) has an acid stable structural unit (a3) selected from the group consisting of an acid stable structural unit (a3-1), an acid stable structural unit (a3-2), and an acid stable structural unit (a3-3). In this case, the total content is selected from the range of 5 to 70 mol%, preferably 10 to 65 mol%, preferably 10 to 60 mol, based on the total structural unit (100 mol%) of the resin (X). % Range is more preferred.

<Acid-stable monomer (a4)>
The resin (A) may have a structural unit derived from an acid-stable monomer other than the above-described structural unit (hereinafter sometimes referred to as “acid-stable monomer (a4)”).
The structural unit derived from the acid stable monomer (a4) is preferable among the structural units that the resin (X) may have in addition to the structural unit (aa) and the structural unit (ab).

［式（ａ４−３）中、
Ｒ^a25及びＲ^a26は、それぞれ独立に、水素原子、ヒドロキシ基を有していてもよい炭素数１〜３のアルキル基、シアノ基、カルボキシ基又は−ＣＯＯＲ^a27〔Ｒ^a27は、炭素数１〜１８の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。但し−ＣＯＯＲ^a27が酸不安定基となるものは除く（すなわち、Ｒ^a27は、３級炭素原子が−Ｏ−と結合するものを含まない）〕を表すか、或いはＲ^a25及びＲ^a26が結合して−ＣＯ−Ｏ−ＣＯ−を形成する。］ The acid stable monomer (a4) is represented by maleic anhydride represented by the following formula (a4-1), itaconic anhydride represented by the formula (a4-2), and formula (a4-3). And an acid-stable monomer having a norbornene ring (hereinafter sometimes referred to as “acid-stable monomer (a4-3)”).

[In the formula (a4-3),
R ^a25 and R ^a26 each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms that may have a hydroxy group, a cyano group, a carboxy group, or —COOR ^a27 [R ^a27 represents 1 to 1 carbon atoms; 18 represents an aliphatic hydrocarbon group, and the methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. Provided that —COOR ^a27 is an acid labile group (that is, R ^a27 does not include those in which a tertiary carbon atom is bonded to —O—)), or R ^a25 and R ^a26 are bonded. To form -CO-O-CO-. ]

In R ^a25 and R ^a26 , the alkyl group which may have a hydroxy group is preferably a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, a 2-hydroxyethyl group, or the like.
The aliphatic hydrocarbon group for R ^a27 is preferably an alkyl group having 1 to 8 carbon atoms and an alicyclic hydrocarbon group having 4 to 18 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms and a carbon number. 4 to 12 alicyclic hydrocarbon groups, more preferably a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.

  Examples of the acid stable monomer (a4-3) include 2-norbornene, 2-hydroxy-5-norbornene, 5-norbornene-2-carboxylic acid, methyl 5-norbornene-2-carboxylate, and 5-norbornene-2- Examples thereof include 2-hydroxy-1-ethyl carboxylate, 5-norbornene-2-methanol and 5-norbornene-2,3-dicarboxylic acid anhydride.

The resin (A) is a structural unit derived from maleic anhydride represented by the formula (a4-1), a structural unit derived from itaconic anhydride represented by the formula (a4-2), and a monomer (a4-3). In the case of having a structural unit selected from the group consisting of structural units derived from, the total content is preferably in the range of 2 to 40 mol% with respect to all structural units (100 mol%) of the resin (A), The range of 3-30 mol% is preferable, and the range of 5-20 mol% is more preferable.
Resin (X) is a structural unit derived from maleic anhydride represented by formula (a4-1), a structural unit derived from itaconic anhydride represented by formula (a4-2), and a monomer (a4-3) In the case of having a structural unit selected from the group consisting of structural units derived from the total content thereof is preferably in the range of 2 to 40 mol% with respect to all structural units (100 mol%) of the resin (X), The range of 3-30 mol% is more preferable, and the range of 5-20 mol% is more preferable.

［式（ａ４−４）中、
Ｌ^a7は、酸素原子又は^＊−Ｔ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を（ｋ２は１〜７の整数を表す。Ｔは酸素原子又はＮＨである。）表し、＊はカルボニル基との結合手を表す。
Ｒ^a28は、水素原子又はメチル基を表す。
Ｗ¹⁰は、置換基を有していてもよいスルトン環基を表す。］ Examples of the acid stable monomer (a4) include those having a sultone ring represented by the formula (a4-4) (hereinafter sometimes referred to as “acid stable monomer (a4-4)”).

[In the formula (a4-4),
L ^a7 represents an oxygen atom or ^* -T— (CH ₂ ) _k2 —CO—O— (k2 represents an integer of 1 to 7. T is an oxygen atom or NH), and * represents a carbonyl group Represents the bond hand.
R ^a28 represents a hydrogen atom or a methyl group.
W ¹⁰ represents a sultone ring group which may have a substituent. ]

置換基を有していてもよいスルトン環基とは、上述の結合手に置き換わった水素原子以外の水素原子がさらに置換基（水素原子以外の１価の基）に置換されたものであり、該置換基は、ヒドロキシ基、シアノ基、炭素数１〜６のアルキル基、炭素数１〜６のフッ化アルキル基、炭素数１〜６のヒドロキシアルキル基、炭素数１〜６のアルコキシ基、炭素数１〜７のアルコキシカルボニル基、炭素数１〜７のアシル基及び炭素数１〜８のアシルオキシ基などが挙げられる。 The sultone ring contained in the sultone ring group is a methylene group contained in the alicyclic hydrocarbon in which two adjacent methylene groups are replaced with one oxygen atom and the other with a sulfonyl group, that is,- Examples of the ring having O—SO ₂ — include those shown below. A typical example of the sultone ring group is one in which one of the hydrogen atoms in the sultone ring shown below is replaced with a bond, and in the formula (a4-4), the bond with L ^a7 corresponds.

The sultone ring group which may have a substituent is a group in which a hydrogen atom other than a hydrogen atom replaced with the above bond is further substituted with a substituent (a monovalent group other than a hydrogen atom), The substituent is a hydroxy group, a cyano group, an alkyl group having 1 to 6 carbon atoms, a fluorinated alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, A C1-C7 alkoxycarbonyl group, a C1-C7 acyl group, a C1-C8 acyloxy group, etc. are mentioned.

Specific examples of the acid stable monomer (a4-4) are shown below.

上記のモノマーにおいて、Ｒ^a28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、構造単位（ａ４−４）の具体例として挙げることができる。

In the above monomer, a structural unit in which a methyl group corresponding to R ^a28 is replaced with a hydrogen atom can also be mentioned as a specific example of the structural unit (a4-4).

When the resin (A) has a structural unit derived from the acid-stable monomer (a4-4), the content thereof is 2 to 40 mol% with respect to the total structural unit (100 mol%) of the resin (A). The range is preferably 3 to 35 mol%, more preferably 5 to 30 mol%.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-4), the content thereof is 2 to 40 mol% with respect to the total structural unit (100 mol%) of the resin (X). The range is preferably 3 to 35 mol%, more preferably 5 to 30 mol%.

Examples of the acid stable monomer (a4) include a monomer having a fluorine atom as shown below [hereinafter referred to as “acid stable monomer (a4-5)” in some cases. ] Can also be used.

Among such acid stable monomers (a4-5), 5- (3,3,3-trifluoro-2-hydroxy-2- (meth) acrylic acid having a monocyclic or polycyclic aliphatic ring [Trifluoromethyl] propyl) bicyclo [2.2.1] hept-2-yl, 6- (3,3,3-trifluoro-2-hydroxy-2- [trifluoromethyl] propyl (meth) acrylate ) Bicyclo [2.2.1] hept-2-yl, 4,4-bis (trifluoromethyl) -3-oxatricyclo [4.2.1.0 ^2,5 ] nonyl (meth) acrylate preferable.

When the resin (A) has a structural unit derived from the acid-stable monomer (a4-5), the total content is 1 to 20 mol with respect to the total structural unit (100 mol%) of the resin (A). % Range is preferable, the range of 2-15 mol% is more preferable, and the range of 3-10 mol% is more preferable.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-5), the total content is 1 to 50 mol with respect to the total structural unit (100 mol%) of the resin (X). % Is preferable, the range of 2 to 45 mol% is more preferable, and the range of 3 to 40 mol% is more preferable.

［式（３）中、
Ｒ¹⁰は、炭素数１〜６のフッ化アルキル基を表す。＊は結合手を表す。］ The resin (A) can contain a structural unit derived from the acid stable monomer (a4) having a group represented by the following formula (3).

[In Formula (3),
R ¹⁰ represents a fluorinated alkyl group having 1 to 6 carbon atoms. * Represents a bond. ]

As the fluorinated alkyl group for R ¹⁰ , a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2 -Tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3, 3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl Group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl Group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2,3 , 3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and A perfluorohexyl group may be mentioned.

The fluorinated alkyl group for R ¹⁰ preferably has 1 to 4 carbon atoms, more preferably a trifluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group, and particularly preferably a trifluoromethyl group.

上記のモノマーにおいて、部分構造Ｍ’を部分構造Ａ’に置き換えたものも、酸安定モノマー（ａ４−６）の具体例として挙げることができる。

As the acid stable monomer (a4) having a group represented by the formula (3), the following acid stable monomer [hereinafter referred to as “acid stable monomer (a4-6)” in some cases. ].

In the above monomer, those in which the partial structure M ′ is replaced with the partial structure A ′ can also be mentioned as specific examples of the acid stable monomer (a4-6).

Moreover, the following can also be mentioned as an acid stable monomer (a4-6).

When the resin (A) has a structural unit derived from the acid-stable monomer (a4-6), the content is 5 to 90 mol% with respect to the total structural unit (100 mol%) of the resin (A). The range is preferably 10 to 80 mol%, more preferably 20 to 70 mol%.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-6), the content thereof is 1 to 70 mol% with respect to the total structural unit (100 mol%) of the resin (X). Is preferable, the range of 3 to 60 mol% is more preferable, and the range of 5 to 50 mol% is more preferable.

［式（４）中、
Ｒ¹¹は置換基を有してもよい炭素数６〜１２の芳香族炭化水素基を表す。
Ｒ¹²は、置換基を有してもよい炭素数１〜１２の炭化水素基を表し、該炭化水素基は、ヘテロ原子を含んでいてもよい。
Ａ^３は、単結合、−（ＣＨ_２）_ｍ10−ＳＯ_２−Ｏ−＊又は−（ＣＨ_２）_ｍ10−ＣＯ−Ｏ−＊を表し、ここに示す−（ＣＨ_２）_ｍ10−に含まれるメチレン基は、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く、−（ＣＨ_２）_ｍ10−に含まれる水素原子は、フッ素原子に置き換わっていてもよい。
ｍ１０は、１〜１２の整数を表す。］ The resin (A) can contain a structural unit derived from the acid stable monomer (a4) having a group represented by the following formula (4).

[In Formula (4),
R ¹¹ represents an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent.
R ¹² represents an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and the hydrocarbon group may contain a hetero atom.
A ³ represents a single bond, — (CH ₂ ) _{m 10} —SO ₂ —O— * or — (CH ₂ ) _{m 10} —CO—O— *, and methylene contained in — (CH ₂ ) _{m 10} — shown here. The group may be replaced with an oxygen atom, a carbonyl group or a sulfonyl group, and the hydrogen atom contained in — (CH ₂ ) _m10 — may be replaced with a fluorine atom.
m10 represents an integer of 1 to 12. ]

Specific examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms in R ¹¹ include those already exemplified in this range. When these aromatic hydrocarbon groups have a substituent, the substituent is an alkyl group having 1 to 4 carbon atoms, a halogen atom, a phenyl group, a nitro group, a cyano group, a hydroxy group, a phenyloxy group, and tert-butylphenyl. Group.

Examples of R ¹¹ include the following groups. Note that * is a bond with a carbon atom.

The hydrocarbon group having 1 to ¹² carbon atoms in R ¹² may be any of a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
The aliphatic hydrocarbon group is typically an alkyl group, and specific examples thereof include those already exemplified in the range of 1 to 12 carbon atoms. Examples of the alicyclic hydrocarbon group include those already exemplified in the range of 12 or less carbon atoms.
In addition, when R < ¹² > is an aliphatic hydrocarbon group, this aliphatic hydrocarbon group may contain the hetero atom. The hetero atom is a halogen atom, a sulfur atom, an oxygen atom, a nitrogen atom or the like [a sulfonyl group or a carbonyl group may be included as a linking group].
Examples of R ¹² containing such a heteroatom include the following groups.

When R ¹² is an aromatic hydrocarbon group, specific examples thereof are the same as those for R ¹¹ .

Examples of A ³ include the following groups.

［式（ａ４−７）中、
Ｒ¹³は、水素原子又はメチル基を表す。
Ｒ¹¹、Ｒ¹²及びＡ^３は、前記と同義である。］ As the acid stable monomer (a4) containing a group represented by the formula (4), the following acid stable monomer [hereinafter referred to as “acid stable monomer (a4-7)” in some cases. ].

[In the formula (a4-7),
R ¹³ represents a hydrogen atom or a methyl group.
R ¹¹ , R ¹² and A ³ are as defined above. ]

上記のモノマーにおいて、部分構造Ｍ’を部分構造Ａ’に置き換えたものも、酸安定モノマー（ａ４−７）の具体例として挙げることができる。 Examples of the acid stable monomer (a4-7) include the following.

In the above monomer, those in which the partial structure M ′ is replaced with the partial structure A ′ can also be mentioned as specific examples of the acid stable monomer (a4-7).

When the resin (A) has a structural unit derived from the acid-stable monomer (a4-7), the content is 5 to 90 mol% with respect to the total structural unit (100 mol%) of the resin (A). The range is preferably 10 to 80 mol%, more preferably 20 to 70 mol%.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-7), the content thereof is 1 to 30 mol% with respect to the total structural unit (100 mol%) of the resin (X). Is preferable, the range of 3 to 25 mol% is more preferable, and the range of 5 to 20 mol% is more preferable.

［式（ａ４−８）中、
環Ｗ^２は、炭素数３〜３６の脂肪族炭化水素環を表す。
Ａ^４は、単結合又は炭素数１〜１７の脂肪族炭化水素基を表す。該脂肪族炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよいが、Ａ^４のうち、酸素原子に結合している原子は炭素原子である。
Ｒ¹⁴は、水素原子、ハロゲン原子、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を表す。
Ｒ¹⁵及びＲ¹⁶は、それぞれ独立に、炭素数１〜６のアルキル基又は炭素数１〜６のハロアルキル基を表す。］ As the acid stable monomer (a4), a monomer represented by the following formula (a4-8) [hereinafter referred to as “acid stable monomer (a4-8)” in some cases). ].

[In the formula (a4-8),
Ring ^{W 2} represents an aliphatic hydrocarbon ring of 3 to 36 carbon atoms.
A ⁴ represents a single bond or an aliphatic hydrocarbon group having 1 to 17 carbon atoms. The methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group, but among A ⁴ , the atom bonded to the oxygen atom is a carbon atom.
R ¹⁴ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms.
R ¹⁵ and R ¹⁶ each independently represents an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms. ]

で示される部分構造は、式（ＫＡ−１）〜式（ＫＡ−２２）の脂環式炭化水素を構成する水素原子の１個がＡ^４との結合手に、脂環式炭化水素環原子に含まれる炭素原子の１つに結合している２つの水素原子が、−Ｏ−ＣＯ−Ｒ¹⁵及び−Ｏ−ＣＯ−Ｒ¹⁶との結合手に置き換わったものを挙げることができる。
環Ｗ^２の脂肪族環は、シクロヘキサン環、アダマンタン環、ノルボルナン環及びノルボルネン環が特に好ましい。 Ring W ² is a monocyclic or polycyclic aliphatic hydrocarbon ring having a carbon number of 3 to 36, the number of carbon atoms is preferably from 5 to 18, 6 to 12 more preferably in the range of. That is, in formula (a4-8)

Partial structure represented in the formula (KA-1) ~ expression bond one hydrogen atom constituting the alicyclic hydrocarbon (KA-22) is the A ^4, an alicyclic hydrocarbon ring atoms Can be mentioned in which two hydrogen atoms bonded to one of the carbon atoms contained in is replaced with a bond to —O—CO—R ¹⁵ and —O—CO—R ¹⁶ .
The aliphatic ring of ring W ² is particularly preferably a cyclohexane ring, an adamantane ring, a norbornane ring or a norbornene ring.

式中、
Ｘ^Ｘ１及びＸ^Ｘ２は、それぞれ独立に、単結合又は置換基を有していてもよい炭素数１〜６のアルキレン基を表し、Ｘ^Ｘ１及びＸ^Ｘ２がともに単結合であることはなく、式（Ｘ^ｘ−Ａ）、式（Ｘ^ｘ−Ｂ）又は式（Ｘ^ｘ−Ｃ）で表される基の総炭素数はそれぞれ１７以下である。 Examples of the aliphatic hydrocarbon group for A ⁴ include the alkanediyl groups and divalent alicyclic hydrocarbon groups exemplified above in the range of 17 or less carbon atoms, and those having a carbon number of 17 or less. For example, it may be an aliphatic hydrocarbon group in which an alkanediyl group and an alicyclic hydrocarbon group are combined. Further, the aliphatic hydrocarbon group of A ⁴ may have a substituent.
Examples of the aliphatic hydrocarbon group include groups represented by the following formula (X ^x -A), formula (X ^x -B), or formula (X ^x -C).

Where
X ^X1 and X ^X2 each independently represent a single bond or an alkylene group having 1 to 6 carbon atoms which may have a substituent, and X ^X1 and X ^X2 are not both single bonds, The total number of carbon atoms of the group represented by (X ^x -A), formula (X ^x -B) or formula (X ^x -C) is 17 or less.

Examples of the group in which the methylene group contained in the aliphatic hydrocarbon group of A ⁴ is replaced with an oxygen atom or a carbonyl group include a methylene group contained in the hydrocarbon group of A ^{aa1 in} the formula (aa) as an oxygen atom or a carbonyl group. And those exemplified by the group replaced by.
Among them, ^{A 4} represents a single _{bond, * - (CH 2) s1} -CO-O - (* represents a binding position to -O-, s1 is an integer of 1-6.) Represented by A group is preferable, and a group represented by a single bond or * —CH ₂ —CO—O— (* represents a bond to —O—) is more preferable.

Specific examples of the alkyl group represented by R ^{14 to} R ¹⁶ include those already exemplified in the range of 1 to 6 carbon atoms. As the haloalkyl group, an alkyl group having a fluorine atom is particularly preferable. The haloalkyl group for R ¹⁵ and R ¹⁶ is preferably a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, or the like, more preferably a trifluoromethyl group, a perfluoroethyl group, or a perfluoropropyl group. It is.
R ¹⁴ is preferably a hydrogen atom or a methyl group.

これらの中でも、

で示される酸安定モノマー（ａ４−８）がより好ましい。 Examples of the acid stable monomer (a4-8) include those shown below. In the following formulae, R ^{14 to} R ¹⁶ and A ⁴ are as defined above.

Among these,

The acid-stable monomer (a4-8) shown by these is more preferable.

上記のモノマーにおいて、Ｒ¹⁴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、構造単位（ａ４−８）の具体例として挙げることができる。 Specific examples of the acid-stable monomer (a4-8) include those represented below.

In the above monomer, a structural unit in which a methyl group corresponding to R ¹⁴ is replaced with a hydrogen atom can also be mentioned as a specific example of the structural unit (a4-8).

［式（ａ４−８−ａ）及び式（ａ４−８−ｂ）中の符号はいずれも、前記と同義である。］ The acid stable monomer (a4-8) can be produced, for example, by reacting a compound represented by the formula (a4-8-a) with a compound represented by the formula (a4-8-b). it can.
Examples of the compound represented by the formula (a4-8-a) include 1-methacryloyloxy-4-oxoadamantane described in JP-A-2002-226436.
Examples of the compound represented by the formula (a4-8-b) include pentafluoropropionic anhydride, heptafluorobutyric anhydride, and trifluoroacetic anhydride.
This reaction is preferably carried out by heating near the boiling point of the compound represented by the formula (a4-8-b) to be used.

[The symbols in formula (a4-8-a) and formula (a4-8-b) are as defined above. ]

When the resin (A) has a structural unit derived from the acid-stable monomer (a4-8), the content is 5 to 90 mol% with respect to the total structural unit (100 mol%) of the resin (A). The range is preferably 10 to 80 mol%, more preferably 20 to 70 mol%.
When the resin (X) has a structural unit derived from the acid-stable monomer (a4-8), the content thereof is 1 to 30 mol% with respect to the total structural unit (100 mol%) of the resin (X). Is preferable, the range of 3 to 25 mol% is more preferable, and the range of 5 to 20 mol% is more preferable.

<Production method of resin>
Resin (X) polymerizes compound (aa ′) and compound (ab ′), or polymerizes compound (aa ′), compound (ab ′), and a monomer that derives another structural unit. You can get it.
The monomer for deriving another structural unit is preferably an acid stable monomer (a4), more preferably an acid stable monomer (a4-6) and / or an acid stable monomer (a4-7), Preferably, it is an acid stable monomer (a4-6).

The resin (A) is obtained by polymerizing a monomer that derives the structural unit (a1) [preferably a monomer that induces the structural unit (a1-1) or the structural unit (a1-2)], and more preferably A monomer derived from the structural unit (a1) and a monomer derived from the acid stable structural unit are copolymerized, and more preferably, the structural unit (a1-1) and / or the structural unit (a1-2). Is a copolymer of a monomer that induces acid, an acid stable structural unit (a2) and / or a monomer that induces acid stable structural unit (a3).
The resin (A) preferably has at least one of the structural unit (a1-1) and the structural unit (a1-2) having an adamantyl group as the structural unit (a1), and the structural unit having an adamantyl group More preferably, it has (a1-1). As the acid stable structural unit (a2), it is preferable to use a structural unit (a2-1) having a hydroxyadamantyl group. The acid stable structural unit (a3) includes at least an acid stable structural unit (a3-1) having a γ-butyrolactone ring and an acid stable structural unit (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring. It is preferable to have one.

When the resin (A) has an acid stable structural unit, the content of the acid stable structural unit may be determined based on the content of the structural unit (a1). The ratio between the content of the structural unit (a1) and the content of the acid-stable structural unit is represented by [structural unit (a1)] / [acid-stable structural unit], and preferably 10 to 80 mol% / 90 to It is 20 mol%, More preferably, it is 20-60 mol% / 80-40 mol%.
When the structural unit (a1) includes a structural unit having an adamantane ring, particularly the structural unit (a1-1), the ratio of the structural unit (a1-1) to the total amount (100 mol%) of the structural unit (a1) Is preferably 15 mol% or more. If it does in this way, there exists a tendency for the dry etching tolerance of the resist pattern obtained from this resist composition containing resin (A) to become more favorable.
In the case where the resin (X) has an acid stable structural unit, the structural unit (aa) and the structural unit (ab) of the resin (X) are converted into an O-A ^aa1 bond and an O-A by the action of an acid. ^In consideration of whether or not the ^ab1 bond is ^broken, a part or all of the structural unit (aa) corresponds to the structural unit (a1), or a part or all of the structural unit (ab) is the structural unit (a1). It is preferable to calculate the content of acid-stable structural units other than the structural unit (aa) and the structural unit (ab) after determining whether or not this is true.

In the present resist composition, when the resin (X) and the resin (A) are used in combination, the mixing mass ratio is determined by the resist composition due to the interaction between the resin and an acid generator described later. It adjusts suitably so that it can manufacture. For example, when the resin (X) has an acid labile group (a1), the mixing mass ratio is preferably 0.1 to 100 parts by mass of the resin (X) with respect to 10 parts by mass of the resin (A). 1-50 mass parts is more preferable.
When resin (X) does not have an acid labile group (a1), 0.01-2 mass parts of resin (X) are preferable with respect to 10 mass parts of resin (A), 0.1-1 Part by mass is more preferable.

Resin (X) and resin (A) can be produced by subjecting the above-described monomers to a known polymerization method (for example, radical polymerization method) and polymerizing (copolymerizing) the same.
The weight average molecular weight of the resin (X) is preferably 5,000 or more, more preferably 8,000 or more, and still more preferably 10,000 or more. Moreover, Preferably it is 80,000 or less, More preferably, it is 60,000 or less, More preferably, it is 50,000 or less.
The weight average molecular weight of the resin (A) is preferably from 2,500 to 50,000, and more preferably from 3,000 to 30,000.
A weight average molecular weight 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.

<Acid generator (hereinafter sometimes referred to as “acid generator (B)”)>
The acid generator (B) is classified into a nonionic type and an ionic type, and any of them may be used in the resist composition of the present invention. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include an onium salt containing an onium cation (for example, a diazonium salt, a phosphonium salt, a sulfonium salt, and an iodonium salt). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, and JP-A 63-163452. No. 62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. A compound that generates an acid by the radiation can 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、置換基を有していてもよい炭素数１〜１７の２価の脂肪族炭化水素基を表す。該脂肪族炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれるメチレン基は、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。 The acid generator contained in the resist composition is preferably an acid generator represented by the following formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”). In the following description, among the acid generators (B1), Z ⁺ having a positive charge is referred to as “organic cation”, and a negative charge obtained by removing the organic cation is referred to as “sulfonate anion”. There is.

In formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a C 1-17 divalent aliphatic hydrocarbon group which may have a substituent. The methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the aliphatic hydrocarbon group is replaced with an oxygen atom, a carbonyl group or a sulfonyl group. May be.
Z ⁺ represents an organic cation.

Examples of the perfluoroalkyl group of Q ¹ and Q ² 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. And perfluorohexyl group.
In formula (B1), Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent aliphatic hydrocarbon group represented by L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic 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 fats which are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group A cyclic hydrocarbon group;
And polycyclic alicyclic hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group and the like. It is done.

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又は炭素数１〜１５の２価の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b4は、炭素数１〜１３の２価の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b3及びＬ^b4の合計炭素数の上限は１３である。
Ｌ^b5は、炭素数１〜１５の２価の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の２価の脂肪族炭化水素基を表し、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b6及びＬ^b7の合計炭素数の上限は１６である。
Ｌ^b8は、炭素数１〜１４の２価の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b9及びＬ^b10は、それぞれ独立に、炭素数１〜１１の２価の脂肪族炭化水素基を表し、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b9及びＬ^b10の合計炭素数の上限は１２である。 Examples of those in which the methylene group contained in the aliphatic hydrocarbon group of L ^b1 is replaced with an oxygen atom or a carbonyl group include formulas (b1-1) to (b1-6). Incidentally, the formula (b1-1) ~ formula (b1-6) are described together the left and right in the equation (B1), the left ^{C (Q 1) (Q 2} ) - bound to, the right side Combines with -Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).

In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or a C 1-15 divalent aliphatic hydrocarbon group, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b3 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b4 represents a divalent aliphatic hydrocarbon group having 1 to 13 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b6 and L ^b7 each independently represent a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a divalent aliphatic hydrocarbon group having 1 to 14 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b9 and L ^b10 each independently represent a divalent aliphatic hydrocarbon group having 1 to 11 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.

L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4), more preferably any one of formulas (b1-1) to (b1-3). A group represented by Formula (b1-1) or Formula (b1-2). Among these, as L ^b1 , a divalent group represented by the formula (b1-1) is preferable, and a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or a methylene group. More preferred.

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 substituent in the aliphatic hydrocarbon group represented by L ^b1 include a halogen atom, a hydroxy group, a carboxy group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, and 2 to 2 carbon atoms. 4 acyl groups, glycidyloxy groups and the like.

Examples of the aliphatic hydrocarbon group for Y include an alkyl group and an alicyclic hydrocarbon.
Examples of the alkyl group include methyl group, ethyl group, 1-methylethyl group (isopropyl group), 1,1-dimethylethyl group (tert-butyl group), 2,2-dimethylethyl group, propyl group, 1- Methylpropyl group, 2,2-dimethylpropyl group, 1-ethylpropyl group, butyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-propylbutyl group, pentyl group, 1-methylpentyl group Hexyl group, 1,4-dimethylhexyl group, heptyl group, 1-methylheptyl group, octyl group, methyloctyl group, methylnonyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group, etc. Examples thereof include a chain or branched alkyl group.
Examples of the alicyclic hydrocarbon group include groups represented by the following formulas (Y1) to (Y11).
Among these, Y is preferably an alkyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably an alicyclic hydrocarbon group having 3 to 12 carbon atoms.

Examples of the group in which the methylene group contained in the aliphatic hydrocarbon group of Y is replaced with an oxygen atom, a sulfonyl group, or a carbonyl group include, for example, —CH ₂ — contained in the alkyl group described above is replaced with an oxygen atom or a carbonyl group. Groups, cyclic ether groups (groups in which one or two methylene groups contained in the alicyclic hydrocarbon group are replaced with oxygen atoms), cyclic ketone groups (one of the methylene groups contained in the alicyclic hydrocarbon group) Or a group in which two are replaced by a carbonyl group), a sultone ring group (a group in which two adjacent methylene groups in an alicyclic hydrocarbon group are replaced by an oxygen atom and a sulfonyl group, respectively) and a lactone Ring groups (two methylene groups adjacent to each other among the methylene groups contained in the alicyclic hydrocarbon group were replaced with oxygen atoms and carbonyl groups, respectively. ), And the like.
Specific examples include groups represented by the following formulas (Y12) to (Y26).

  A preferred group of the alicyclic hydrocarbon group of Y is any one of the following formula (Y11), formula (Y14), formula (Y15), formula (Y16), and formula (Y19), more preferably formula (Y Y11), a formula (Y14), a formula (Y15), and a formula (Y19), and more preferably an alicyclic hydrocarbon group represented by any one of the formula (Y11) and the formula (Y14).

Examples of the substituent of the aliphatic hydrocarbon group in Y include a halogen atom (excluding a fluorine atom), a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, and carbon. An aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 (wherein R ^b1 is a carbon number of 1; Represents a hydrocarbon group of ˜16. J2 represents an integer of 0 to 4). The aromatic hydrocarbon group and aralkyl group which are substituents for Y may further have, for example, an alkyl group, a halogen atom or a hydroxy group.

Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
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, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, n-hexoxy group and the like.
As aromatic hydrocarbon group, phenyl group, naphthyl group, anthranyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl Groups, anthryl groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl group, naphthylethyl group and the like.
Examples of the acyl group include acetyl, propionyl, butyryl and the like.

Examples of Y include the following.

When Y is an alkyl group and L ^b1 is a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, the methylene group of the divalent aliphatic hydrocarbon group bonded to Y is oxygen It is preferably replaced by an atom or a carbonyl group. In this case, the methylene group constituting the alkyl group of Y is not replaced with an oxygen atom or a carbonyl group.

  Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably an adamantyl group which may have a substituent, and more preferably an adamantyl group. A group, an oxoadamantyl group and a hydroxyadamantyl group.

The sulfonate anion in the salt represented by the formula (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-9). In the following formulae, the definition of the substituent has the same meaning as described above, and the substituents 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 in the salt represented by the formula (B1) include the anions described in JP 2010-204646 A.

Further preferably, it is a sulfonate anion in which L ^b1 is a group represented by the formula (b1-1) and Y is an alicyclic hydrocarbon group represented by the formula (Y1) or the formula (Y2). .
Examples of the sulfonate anion in which Y is an unsubstituted aliphatic hydrocarbon group include those represented by any of the following formulas (b1-s-0) to (b1-s-9).

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having a hydroxy group include those represented by any of the following formulas (b1-s-10) to (b1-s-18). .

Examples of the sulfonate anion in which Y is a cyclic ketone group include those represented by any of the following formulas (b1-s-19) to (b1-s-29).

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having an aromatic group include those represented by any of the following formulas (b1-s-30) to (b1-s-35). It is done.

Examples of the sulfonate anion in which Y is the lactone ring group or the sulfonic acid ring group include those represented by any of the following formulas (b1-s-36) to (b1-s-41). It is done.

式（ｂ２−１）〜式（ｂ２−４）において、
Ｒ^b4、Ｒ^b5及びＲ^b6は、それぞれ独立に、炭素数１〜３０の炭化水素基を表す。該炭化水素基は、炭素数１〜３０のアルキル基、炭素数３〜１８の脂環式炭化水素基及び炭素数６〜１８の芳香族炭化水素基が好ましく、該アルキル基は、ヒドロキシ基、炭素数１〜１２のアルコキシ基又は炭素数６〜１８の芳香族炭化水素基を有していてもよく、該脂環式炭化水素基は、ハロゲン原子、炭素数２〜４のアシル基又はグリシジルオキシ基を有していてもよく、該芳香族炭化水素基は、ハロゲン原子、ヒドロキシ基、炭素数１〜１８のアルキル基、炭素数３〜１８の脂環式炭化水素基又は炭素数１〜１２のアルコキシ基を有していてもよい。
Ｒ^b7及びＲ^b8は、それぞれ独立に、ヒドロキシ基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表す。
ｍ２及びｎ２は、それぞれ独立に０〜５の整数を表す。
Ｒ^b9及びＲ^b10は、それぞれ独立に、炭素数１〜１８のアルキル基又は炭素数３〜１８の脂環式炭化水素基を表すか、Ｒ^b9とＲ^b10は、それらが結合する硫黄原子とともに互いに結合して３員環〜１２員環（好ましくは３員環〜７員環）を形成する。該環に含まれるメチレン基は、酸素原子、硫黄原子又はカルボニル基に置き換わってもよい。
Ｒ^b11は、水素原子、炭素数１〜１８のアルキル基、炭素数３〜１８の脂環式炭化水素基又は炭素数６〜１８の芳香族炭化水素基を表す。
Ｒ^b12は、炭素数１〜１８の炭化水素基を表す。該炭化水素基において、芳香族炭化水素基は、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数３〜１８の脂環式炭化水素基又は炭素数１〜１２のアルキルカルボニルオキシ基を有していてもよい。
Ｒ^b11とＲ^b12は、それらが結合する−ＣＨ−ＣＯ−とともに３員環〜１２員環（好ましくは３員環〜７員環）を形成していてもよい。該環に含まれるメチレン基は、酸素原子、硫黄原子又はカルボニル基に置き換わってもよい。 Examples of the organic cation (Z ⁺ ) in the acid generator (B1) include an organic onium cation such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, an organic benzothiazolium cation, and an organic phosphonium cation. An organic sulfonium cation and an organic iodonium cation are preferable, and an organic cation represented by any of the following formulas (b2-1) and (b2-4) is more preferable.

In formula (b2-1) to formula (b2-4),
R ^b4 , R ^b5 and R ^b6 each independently represents a hydrocarbon group having 1 to 30 carbon atoms. The hydrocarbon group is preferably an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms and an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alkyl group is a hydroxy group, It may have 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 may be a halogen atom, an acyl group having 2 to 4 carbon atoms, or glycidyl. The aromatic hydrocarbon group may have an oxy group, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 1 to 1 carbon atoms. It may have 12 alkoxy groups.
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, or R ^b9 and R ^b10 together with a sulfur atom to which they are bonded. They are bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring). The methylene group contained in the ring may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.
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 ^b12 represents a hydrocarbon group having 1 to 18 carbon atoms. In the hydrocarbon group, the aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkyl group having 1 to 12 carbon atoms. It may have an alkylcarbonyloxy group.
R ^b11 and R ^b12 may form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) with —CH—CO— to which they are bonded. The methylene group contained in the ring may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.

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

芳香族炭化水素基としては、フェニル基、ナフチル基、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、アントリル基、フェナントリル基、２，６−ジエチルフェニル基、２−メチル−６−エチルフェニル等のアリール基等が挙げられる。 Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. .
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and dimethylcyclohexane. Examples thereof include a cycloalkyl group such as a hexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic saturated hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups. * Represents a bond with an adamantane ring or a cyclohexane ring.

Aromatic hydrocarbon groups include phenyl, naphthyl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl, anthryl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

Preferred alkyl groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl and 2-ethylhexyl. In particular, the alkyl group of R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
Preferred alicyclic hydrocarbon groups are cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) -1 -An alkyl group and an isobornyl group. In particular, the alicyclic hydrocarbon group of R ^{b9 to} R ^b11 preferably has 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.
Preferred aromatic hydrocarbon groups are phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, biphenylyl group and naphthyl group. Etc. are preferable.
An aromatic hydrocarbon group substituted with an alkyl group is typically an aralkyl group, and examples thereof include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.

Examples of the ring formed together with the sulfur atom to which R ^b9 and R ^b10 are bonded include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and 1,4-oxathian-4-ium. A ring etc. are mentioned.
Examples of the ring formed with —CH—CO— in which R ^b11 and R ^b12 are bonded include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、炭素数１〜１８の脂肪族炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
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。 As an organic cation represented by Formula (b2-1)-Formula (b2-4), what was described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned.
Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, and the cation represented by the formula (b2-1-1) is more preferable. Are triphenylsulfonium cations (in formula (b2-1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cations (in formula (b2-1-1), v2 = w2 = 0, x2 = 1 And R ^b21 is a methyl group.) Or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 1, and R ^b19 , R ^b20 and R ^b21 are all methyl. Group.)

R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
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. .

The alkyl group of R ^{b19 to} R ^b21 preferably has 1 to 12 carbon atoms.
The alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. Is

The specific example of the cation (b2-1-1) which is a suitable organic cation is shown.

Moreover, as an organic cation, the following organic cations can also be mentioned as a suitable thing among the organic cations represented by Formula (b2-3).

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anions and cations can be arbitrarily combined. Table 2 shows combinations of these sulfonate anions and organic cations. In Table 2, the sulfonate anion represented by the formula (b1-s-1) is represented as “(b1-s-1)” according to the formula number, and the formula (b2-c-1) Is represented by “(b2-c-1)” or the like according to the formula number.

  The acid generator (B1) is more preferably one represented by any of the following formulas (B1-1) to (B1-17). Among them, the formula (B1-2), the formula (B1-3), the formula (B1-6), the formula (B1-7), or the formulas (B1-11) to (B1) containing a triphenylsulfonium cation or a tolylsulfonium cation. What is represented by -14) is more preferable.

  As described above, the acid generator (B) may contain an acid generator different from the acid generator (B1). In this case, the acid generator (B1) in the total amount of the acid generator (B). ) Is preferably 70% by mass or more, and more preferably 90% by mass or more. However, it is more preferable that the acid generator (B) in the resist composition of the present invention is substantially only the acid generator (B1).

［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。］ <Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition of the present invention preferably contains a basic compound (C).
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.

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

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

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

［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。
］
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、２，２−ジメチルプロピオニル基等が挙げられる。

[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.
]
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

［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. ]

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- Diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and the like.
Among these, diisopropylaniline is preferable, and 2,6-diisopropylaniline is particularly preferable.

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

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

<Solvent (D)>
The resist composition of the present invention preferably contains a solvent (D). The solvent (D) depends on the type and amount of the resin (X) to be used, the type and amount of the acid generator, 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.

  Examples of suitable solvents (D) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and Examples thereof include esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; and cyclic esters such as γ-butyrolactone. Only 1 type may be used for a solvent (D) and it may use 2 or more types together.

<Other ingredients>
The resist composition of the present invention may contain components other than the above-described components (hereinafter sometimes referred to as “component (F)”) as necessary. Component (F) is an additive widely used in this technical field, and examples thereof include a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, and a dye.

<Preparation of resist composition>
The resist composition of the present invention comprises a resin [particularly, a combination of resin (A) and resin (X)], an acid generator, and a basic compound (C), a solvent (D) and components (if necessary). It can be prepared by mixing F).
Furthermore, you may mix a component (F) as needed. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature range from the range of 10-40 degreeC according to the kind etc. of resin, the solubility with respect to solvent (D), such as resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.01 to 0.2 μm.

  The content of the resin with respect to the resist composition of the present invention is preferably 80% by mass or more and 99% by mass or less with respect to the total mass of the solid content of the resist composition of the present invention. “Solid content” means the total of components excluding the solvent (D) from the resist composition of the present invention. The solid content and the content of each component relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  The content of the acid generator in the resist composition of the present invention is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and preferably 30 parts by mass or less with respect to 100 parts by mass of the resin. More preferably, it is 25 parts by mass or less.

  When the basic compound (C) is used in the resist composition of the present invention, the content thereof is preferably about 0.01 to 1% by mass relative to the total mass of the solid content of the resist composition of the present invention.

When the solvent (D) is used in the resist composition of the present invention, the content can be appropriately adjusted according to the type of the resin (X). The content of the solvent (D) is preferably 90% by mass or more, more preferably 92% by mass or more, and further preferably 94% by mass or more, with respect to the total mass of the resist composition of the present invention. Is 99 mass% or less, More preferably, it is 99.9 mass% or less.
When the resist composition contains the solvent (D) at such a content, a thin composition layer having a thickness of about 30 to 300 nm can be formed in the resist pattern manufacturing method described later.

  The content of each of the resin [resin (A) and / or resin (X)], acid generator, solvent (D) and basic compound (C) depends on the amount used in preparing the resist composition. It is controllable, and after preparing the resist composition, the resist composition of the present invention can be obtained by subjecting it to known analysis means such as gas chromatography and liquid chromatography.

  In addition, when using a component (F) for the resist composition of this invention, suitable content can also be adjusted according to the kind of the said component (F).

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

  The application of the resist composition onto the substrate can be performed by a coating apparatus such as a spin coater that is widely used for applying a resist material for semiconductor microfabrication. The film thickness of the coating film can be adjusted by variously adjusting the conditions (coating conditions) of the coating apparatus, and the coating conditions can be adjusted so that the coating film has a desired film thickness by performing appropriate preliminary experiments. You can choose. Various substrates to be subjected to microfabrication can be selected as the substrate before applying the resist composition. Before applying the resist composition, the substrate may be washed or an antireflection film may be formed. The antireflection film can be formed using a commercially available composition for organic antireflection films.

Drying is performed using, for example, a heating device such as a hot plate (so-called pre-baking), a decompressing device, or a combination thereof. As a result, the solvent is removed by evaporation from the resist composition, and a composition layer is formed. As for the temperature in this case, about 50-200 degreeC is illustrated, for example. The pressure is exemplified by 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.) can be used such as those that convert the wavelength of the laser light from the above and radiate the harmonic laser light in the far ultraviolet region or the vacuum ultraviolet region. Further, the exposure machine may irradiate an electron beam or extreme ultraviolet light (EUV).
By exposing through a mask, an exposed part (exposed part) and an unexposed part (unexposed part) are generated in the composition layer. In the composition layer of the exposed portion, the acid generator contained in the composition layer receives exposure energy to generate an acid, and further, by the action of the generated acid, the resin (A) [or having an acid labile group Resin (X)] causes an acid labile group to undergo a deprotection reaction, and as a result, resin (A) in the composition layer of the exposed portion becomes soluble in an aqueous alkali solution. On the other hand, since the exposure energy is not received in the unexposed area, the resin (A) remains insoluble or hardly soluble in the alkaline aqueous solution. Thus, the solubility with respect to aqueous alkali solution will differ significantly between the composition layer in an exposed part, and the composition layer in an unexposed part.

The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The heated composition layer is usually developed using an alkali developer using a developing device.
The development referred to here is by bringing the composition layer after heating into contact with an alkaline aqueous solution, thereby dissolving the exposed composition layer in the alkaline aqueous solution and leaving the unexposed composition layer on the substrate. A resist pattern is manufactured on the substrate. 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).
After development, it is preferable to rinse with ultrapure water to remove water remaining on the substrate and the pattern.

<Application>
The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure. is there.

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.
In the following examples, the structure of the compound was confirmed by mass spectrometry (LC is Agilent Model 1100, MASS is Agilent LC / MSD Model).
The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
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（Ｇ−２）で表される化合物８８．００部、メチルイソブチルケトン６１６．００部及びピリジン６０．９８部を、２３℃で３０分間攪拌混合し、０℃まで冷却した。同温度を保持したまま、得られた混合物に、式（Ｇ−１）で表される化合物１９９．１７部を、１時間かけて添加した。さらに、これを１０℃程度まで昇温し、同温度で１時間攪拌した。得られた反応混合物に、ｎ−へプタン１４４６．２２部及び２％塩酸水溶液７０３．４１部を加え、２３℃で３０分間攪拌した。攪拌・静置し、分液することにより回収された有機層に、２％塩酸水溶液３３７．６４部を加え、２３℃で３０分間攪拌、静置し、分液することにより有機層を回収した。回収された有機層に、イオン交換水３６１．５６部を加え、２３℃で３０分間攪拌、静置し、分液することにより有機層を水洗した。回収された有機層に、１０％炭酸カリウム水溶液４４３．９２部を仕込み、２３℃で３０分間攪拌、静置し、分液することにより有機層を回収した。このような洗浄操作を２回繰り返した。回収された有機層に、イオン交換水３６１．５６部を加え、２３℃で３０分間攪拌、静置し、分液することにより有機層を回収した。このような水洗操作を５回繰り返した。回収された有機層を濃縮し式（Ｍ−Ｇ）で表される化合物１６３．６５部を得た。
質量スペクトル：２７６．０（分子イオンピーク） Synthesis Example 1 [Synthesis of Compound Represented by Formula (MG)]

88.00 parts of the compound represented by the formula (G-2), 616.00 parts of methyl isobutyl ketone and 60.98 parts of pyridine were stirred and mixed at 23 ° C. for 30 minutes and cooled to 0 ° C. While maintaining the same temperature, 199.17 parts of the compound represented by the formula (G-1) was added to the obtained mixture over 1 hour. Furthermore, this was heated up to about 10 degreeC and stirred at the same temperature for 1 hour. To the obtained reaction mixture, 1446.22 parts of n-heptane and 703.41 parts of 2% aqueous hydrochloric acid were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the organic layer recovered by stirring and standing, and separating the liquid, 337.64 parts of a 2% hydrochloric acid aqueous solution was added, stirred at 23 ° C. for 30 minutes, and allowed to separate, and the organic layer was recovered by liquid separation. . To the recovered organic layer, 361.56 parts of ion-exchanged water was added, and the mixture was stirred and allowed to stand at 23 ° C. for 30 minutes, followed by liquid separation to wash the organic layer with water. The recovered organic layer was charged with 443.92 parts of a 10% aqueous potassium carbonate solution, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to recover the organic layer. Such washing operation was repeated twice. To the recovered organic layer, 361.56 parts of ion-exchanged water was added, and the mixture was stirred and allowed to stand at 23 ° C. for 30 minutes, followed by liquid separation to recover the organic layer. Such washing operation was repeated 5 times. The collected organic layer was concentrated to obtain 163.65 parts of a compound represented by the formula (MG).
Mass spectrum: 276.0 (molecular ion peak)

式（Ｑ−２）で表される化合物９．６０部、テトラヒドロフラン３８．４０部及びピリジン５．９９部を、２３℃で３０分間攪拌混合し、０℃まで冷却した。同温度を保持したまま、得られた混合物に、式（Ｑ−１）で表される化合物１４．００部を、１時間かけて添加した。さらに、これを１０℃程度まで昇温し、同温度で１時間攪拌した。得られた式（Ｑ−３）で表される化合物を含む反応混合物に、式（Ｑ−４）で表される化合物（１−（３−ジメチルアミノプロピル）−３−エチルカルボジイミド塩酸塩）１４．５１部及び式（Ｑ−５）で表される化合物８．２０部を添加し、２３℃で３時間攪拌した。得られた反応溶液に、酢酸エチル２７１．９５部及び５％塩酸水溶液１６．５７部を加え、２３℃で３０分間攪拌した。静置、分液することにより回収された有機層に、飽和炭酸水素ナトリウム水溶液６３．６４部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を洗浄した。このような洗浄操作を２回繰り返した。洗浄後の有機層に、イオン交換水６７．９９部を仕込み２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を５回繰り返した。水洗後の有機層を濃縮した。得られた濃縮物に、酢酸エチル１０７．７１部を添加し完全に溶解するまで攪拌し、ｎ−ヘプタン６４６．２６部を滴下した。滴下終了後、２３℃で３０分間攪拌し、ろ過することにより、式（Ｍ−Ｑ）で表される化合物１５．１１部を得た。
ＭＳ（質量分析）：４８６．２（分子イオンピーク） Synthesis Example 2: [Synthesis of Compound Represented by Formula (MQ)]

9.60 parts of the compound represented by the formula (Q-2), 38.40 parts of tetrahydrofuran and 5.99 parts of pyridine were stirred and mixed at 23 ° C. for 30 minutes and cooled to 0 ° C. While maintaining the same temperature, 14.00 parts of the compound represented by the formula (Q-1) was added to the obtained mixture over 1 hour. Furthermore, this was heated up to about 10 degreeC and stirred at the same temperature for 1 hour. To the reaction mixture containing the compound represented by the formula (Q-3) thus obtained, the compound represented by the formula (Q-4) (1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride) 14 .51 parts and 8.20 parts of the compound represented by the formula (Q-5) were added and stirred at 23 ° C. for 3 hours. To the obtained reaction solution, 271.95 parts of ethyl acetate and 16.57 parts of 5% aqueous hydrochloric acid were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the organic layer recovered by standing and separating, 63.64 parts of a saturated aqueous sodium hydrogen carbonate solution was added, stirred at 23 ° C. for 30 minutes, and allowed to stand and separate to wash the organic layer. Such washing operation was repeated twice. The organic layer after washing was charged with 67.9 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such washing operation was repeated 5 times. The organic layer after washing with water was concentrated. To the obtained concentrate, 107.71 parts of ethyl acetate was added and stirred until completely dissolved, and 646.26 parts of n-heptane was added dropwise. After completion of dropping, the mixture was stirred at 23 ° C. for 30 minutes and filtered to obtain 15.11 parts of a compound represented by the formula (MQ).
MS (mass spectrometry): 486.2 (molecular ion peak)

式（Ｒ−２）で表される化合物６．３２部、テトラヒドロフラン３０．００部及びピリジン５．９９部を、２３℃で３０分間攪拌混合し、０℃まで冷却した。同温度を保持したまま、得られた混合物に、式（Ｒ−１）で表される化合物１４．００部を、１時間かけて添加し、更に、１０℃程度まで温度を上げ、同温度で１時間攪拌した。得られた式（Ｒ−３）で表される化合物を含む反応混合物に、式（Ｒ−４）で表される化合物（１−（３−ジメチルアミノプロピル）−３−エチルカルボジイミド塩酸塩）１４．５１部及び式（Ｒ−５）で表される化合物８．２０部を添加し、２３℃で３時間攪拌した。得られた反応溶液に、酢酸エチル２７０部及び５％塩酸水溶液１６．５７部を加え、２３℃で３０分間攪拌した。静置、分液することにより回収された有機層に、飽和炭酸水素ナトリウム水溶液６５部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を洗浄した。
このような洗浄操作を２回繰り返した。洗浄後の有機層に、イオン交換水６５部を仕込み２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を５回繰り返した。水洗後の有機層を濃縮した。得られた濃縮物を、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：ｎ−ヘプタン／酢酸エチル）することにより、式（Ｍ−Ｒ）で表される化合物９．９０部を得た。
ＭＳ（質量分析）：４３４．１（分子イオンピーク） Synthesis Example 3: Synthesis of compound represented by formula (MR)

6.32 parts of the compound represented by the formula (R-2), 30.00 parts of tetrahydrofuran and 5.99 parts of pyridine were mixed with stirring at 23 ° C. for 30 minutes, and cooled to 0 ° C. While maintaining the same temperature, 14.00 parts of the compound represented by the formula (R-1) was added to the obtained mixture over 1 hour, and the temperature was further increased to about 10 ° C. Stir for 1 hour. The reaction mixture containing the compound represented by the formula (R-3) thus obtained was added to the compound (1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride) 14 represented by the formula (R-4). .51 parts and 8.20 parts of the compound represented by the formula (R-5) were added and stirred at 23 ° C. for 3 hours. To the obtained reaction solution, 270 parts of ethyl acetate and 16.57 parts of 5% aqueous hydrochloric acid were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the organic layer recovered by standing and separating, 65 parts of a saturated aqueous sodium hydrogen carbonate solution was added, stirred at 23 ° C. for 30 minutes, and allowed to stand and separate to wash the organic layer.
Such washing operation was repeated twice. The organic layer after washing was charged with 65 parts of ion exchanged water, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such washing operation was repeated 5 times. The organic layer after washing with water was concentrated. The obtained concentrate is subjected to column fractionation (column fractionation conditions, stationary phase: silica gel 60-200 mesh, manufactured by Merck & Co., Ltd., developing solvent: n-heptane / ethyl acetate), and expressed by the formula (MR). 9.90 parts of compound were obtained.
MS (mass spectrometry): 434.1 (molecular ion peak)

式（Ｓ−２）で表される化合物７．０８部、テトラヒドロフラン３０．００部及びピリジン５．９９部を、２３℃で３０分間攪拌混合し、０℃まで冷却した。同温度を保持したまま、得られた混合物に、式（Ｓ−１）で表される化合物１４．００部を、１時間かけて添加し、更に、１０℃程度まで温度を上げ、同温度で１時間攪拌した。得られた式（Ｓ−３）で表される化合物を含む反応混合物に、式（Ｓ−４）で表される化合物（１−（３−ジメチルアミノプロピル）−３−エチルカルボジイミド塩酸塩）１４．５１部及び式（Ｓ−５）で表される化合物８．２０部を添加し、２３℃で３時間攪拌した。得られた反応溶液に、酢酸エチル２７０部及び５％塩酸水溶液１６．５７部を加え、２３℃で３０分間攪拌した。静置、分液することにより回収された有機層に、飽和炭酸水素ナトリウム水溶液６５部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を洗浄した。
このような洗浄操作を２回繰り返した。洗浄後の有機層に、イオン交換水６５部を仕込み２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を５回繰り返した。水洗後の有機層を濃縮した。得られた濃縮物を、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：ｎ−ヘプタン／酢酸エチル）することにより、式（Ｍ−Ｓ）で表される化合物１０．２４部を得た。
ＭＳ（質量分析）：４４６．１（分子イオンピーク） Synthesis Example 4: [Synthesis of Compound Represented by Formula (MS)]

7.08 parts of the compound represented by the formula (S-2), 30.00 parts of tetrahydrofuran and 5.99 parts of pyridine were stirred and mixed at 23 ° C. for 30 minutes and cooled to 0 ° C. While maintaining the same temperature, 14.00 parts of the compound represented by formula (S-1) was added to the obtained mixture over 1 hour, and the temperature was further increased to about 10 ° C. Stir for 1 hour. The reaction mixture containing the compound represented by the formula (S-3) thus obtained was added to the compound (1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride) 14 represented by the formula (S-4). .51 parts and 8.20 parts of the compound represented by the formula (S-5) were added and stirred at 23 ° C. for 3 hours. To the obtained reaction solution, 270 parts of ethyl acetate and 16.57 parts of 5% aqueous hydrochloric acid were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the organic layer recovered by standing and separating, 65 parts of a saturated aqueous sodium hydrogen carbonate solution was added, stirred at 23 ° C. for 30 minutes, and allowed to stand and separate to wash the organic layer.
Such washing operation was repeated twice. The organic layer after washing was charged with 65 parts of ion exchanged water, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such washing operation was repeated 5 times. The organic layer after washing with water was concentrated. The obtained concentrate is subjected to column fractionation (column fractionation conditions, stationary phase: silica gel 60-200 mesh, manufactured by Merck & Co., Ltd., developing solvent: n-heptane / ethyl acetate), and expressed by the formula (MS). 10.24 parts of compound were obtained.
MS (mass spectrometry): 446.1 (molecular ion peak)

式（Ｖ−２）で表される化合物６．３２部、テトラヒドロフラン３０．００部及びピリジン５．９９部を、２３℃で３０分間攪拌混合した後、０℃まで冷却した。同温度を保持したまま、得られた混合物に、式（Ｖ−１）で表される化合物１４．００部を、１時間かけて添加し、さらに、１０℃程度まで温度を上げ、同温度で１時間攪拌した。得られた式（Ｖ−３）で表される化合物を含む反応混合物に、式（Ｖ−４）で表される化合物（１−（３−ジメチルアミノプロピル）−３−エチルカルボジイミド塩酸塩）１４．５１部及び式（Ｖ−５）で表される化合物１１．７４部を添加し、２３℃で３時間攪拌した。得られた反応溶液に、酢酸エチル３００部及び５％塩酸水溶液１６．５７部を加え、２３℃で３０分間攪拌した。静置、分液することにより回収された有機層に、飽和炭酸水素ナトリウム水溶液６５部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を洗浄した。このような洗浄操作を２回繰り返した。洗浄後の有機層に、イオン交換水１００部を仕込み２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。このような水洗操作を５回繰り返した。水洗後の有機層を濃縮した。得られた濃縮物を、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：ｎ−ヘプタン／酢酸エチル）することにより、式（Ｍ−Ｖ）で表される化合物１６．８９部を得た。
ＭＳ（質量分析）：４９０．２（分子イオンピーク） Synthesis Example 5: [Synthesis of Compound Represented by Formula (MV)]

6.32 parts of the compound represented by the formula (V-2), 30.00 parts of tetrahydrofuran and 5.99 parts of pyridine were stirred and mixed at 23 ° C. for 30 minutes, and then cooled to 0 ° C. While maintaining the same temperature, 14.00 parts of the compound represented by formula (V-1) was added to the obtained mixture over 1 hour, and the temperature was further increased to about 10 ° C. Stir for 1 hour. The reaction mixture containing the compound represented by the formula (V-3) thus obtained was added to the compound (1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride) 14 represented by the formula (V-4). .51 parts and 11.74 parts of the compound represented by the formula (V-5) were added and stirred at 23 ° C. for 3 hours. To the obtained reaction solution, 300 parts of ethyl acetate and 16.57 parts of 5% aqueous hydrochloric acid were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the organic layer recovered by standing and separating, 65 parts of a saturated aqueous sodium hydrogen carbonate solution was added, stirred at 23 ° C. for 30 minutes, and allowed to stand and separate to wash the organic layer. Such washing operation was repeated twice. The organic layer after washing was charged with 100 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. Such washing operation was repeated 5 times. The organic layer after washing with water was concentrated. The obtained concentrate is subjected to column fractionation (column fractionation conditions, stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., Ltd., developing solvent: n-heptane / ethyl acetate), and expressed by the formula (MV). 16.89 parts of compound were obtained.
MS (mass spectrometry): 490.2 (molecular ion peak)

Resin Synthesis The compounds (monomers) used in the resin synthesis are shown below.

以下、これらのモノマーを「モノマー（Ｍ−Ａ）」〜「モノマー（Ｍ−Ｖ）」という。

Hereinafter, these monomers are referred to as “monomer (MA)” to “monomer (MV)”.

Example 1 [Synthesis of Resin X1]
Monomer (MG) and monomer (MF) are used as monomers, and mixed so that the molar ratio (monomer (ME): monomer (MG)) is 90:10. A 1.2 mass times amount of dioxane was added to form a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and about 5% at 72 ° C. Heated for hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin X1 (copolymer) having a weight average molecular weight of 1.4 × 10 ^{4 in} a yield of 85%. It was. This resin X1 has the following structural units.

Example 2 [Synthesis of Resin X2]
Monomer (MG) and monomer (MH) are used as monomers and mixed so that the molar ratio (monomer (MG): monomer (MH)) is 90:10. A 1.2 mass times amount of dioxane was added to form a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 72 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin X2 (copolymer) having a weight average molecular weight of 1.4 × 10 ^{4 in} a yield of 82%. It was. This resin X2 has the following structural units.

Example 3 [Synthesis of Resin X3]
Monomer (MG) and monomer (MI) are used as monomers and mixed so that the molar ratio (monomer (MG): monomer (MI)) is 90:10. A 1.2 mass times amount of dioxane was added to form a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 72 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin X3 (copolymer) having a weight average molecular weight of 1.3 × 10 ^{4 in} a yield of 86%. It was. This resin X3 has the following structural units.

Example 4 [Synthesis of Resin X4]
Monomer (MG) and monomer (MJ) are used as the monomers, and mixed so that the molar ratio (monomer (MG): monomer (MJ)) is 90:10. A 1.2 mass times amount of dioxane was added to form a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 72 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin X4 (copolymer) having a weight average molecular weight of 1.3 × 10 ^{4 in} a yield of 80%. It was. This resin X4 has the following structural units.

Example 5 [Synthesis of Resin X5]
Monomer (MG) and monomer (M-K) are used as the monomers and mixed so that the molar ratio (monomer (MG): monomer (M-K)) is 90:10. A 1.2 mass times amount of dioxane was added to form a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 72 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin X5 (copolymer) having a weight average molecular weight of 1.3 × 10 ^{4 in} a yield of 78%. It was. This resin X5 has the following structural units.

Example 6 [Synthesis of Resin X6]
Monomer (MG) and monomer (ML) are used as monomers and mixed so that the molar ratio (monomer (MG): monomer (ML)) is 90:10. A 1.2 mass times amount of dioxane was added to form a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 72 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin X6 (copolymer) having a weight average molecular weight of 1.4 × 10 ^{4 in} a yield of 79%. It was. This resin X6 has the following structural units.

Example 7 [Synthesis of Resin X7]
As a monomer, a monomer (MG), a monomer (MH), and a monomer (MQ) are used, and a molar ratio thereof (monomer (MG): monomer (MH): monomer (MQ) ) Was 80:10:10, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The 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 2.2. A × 10 ⁴ resin X7 (copolymer) was obtained in a yield of 78%. This resin X7 has the following structural units.

Example 8 [Synthesis of Resin X8]
Monomers (M-R) and monomers (M-H) are used as monomers and mixed so that the molar ratio (monomer (M-R): monomer (M-H)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved 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 2.3. A × 10 ⁴ resin X8 (copolymer) was obtained in a yield of 76%.
This resin X8 has the following structural units.

Example 9 [Synthesis of Resin X9]
Monomer (MS) and monomer (M-H) are used as monomers and mixed so that the molar ratio (monomer (MS): monomer (M-H)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved 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 2.1. A × 10 ⁴ resin X9 (copolymer) was obtained in a yield of 78%.
This resin X9 has the following structural units.

Example 10 [Synthesis of Resin X10]
Monomer (MR) and monomer (MF) are used as monomers and mixed so that the molar ratio (monomer (MR): monomer (MF)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The 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 2.2. A × 10 ⁴ resin X10 (copolymer) was obtained in a yield of 72%. This resin X10 has the following structural units.

Example 11 [Synthesis of Resin X11]
Monomers (M-R) and monomers (M-I) are used as monomers and mixed so that the molar ratio (monomer (M-R): monomer (M-I)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved 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 2.4. A × 10 ⁴ resin X11 (copolymer) was obtained in a yield of 70%. This resin X11 has the following structural units.

Example 12 [Synthesis of Resin X12]
Monomers (M-R) and monomers (M-J) are used as monomers and mixed so that the molar ratio (monomer (M-R): monomer (M-J)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved 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 2.0. A × 10 ⁴ resin X12 (copolymer) was obtained in a yield of 73%. This resin X12 has the following structural units.

Example 13 [Synthesis of Resin X13]
Monomer (MR) and monomer (ML) are used as monomers and mixed so that the molar ratio (monomer (MR): monomer (ML)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, and this resin was filtered twice, and the weight average molecular weight was 1.9. × 10 ⁴ resin X13 (copolymer) was obtained in 74% yield. This resin X13 has the following structural units.

Example 14 [Synthesis of Resin X14]
Monomer (MR) and monomer (MB) are used as monomers and mixed so that the molar ratio (monomer (MR): monomer (MB)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, and this resin was filtered twice, and the weight average molecular weight was 1.9. A × 10 ⁴ resin X14 (copolymer) was obtained in a yield of 76%. This resin X14 has the following structural units.

Example 15 [Synthesis of Resin X15]
Monomer (MV) and monomer (MH) are used as monomers and mixed so that the molar ratio (monomer (MV): monomer (MH)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved 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 2.1. A × 10 ⁴ resin X15 (copolymer) was obtained in a yield of 71%. This resin X15 has the following structural units.

Example 16 [Synthesis of Resin X16]
Monomers (MV) and (MI) are used as the monomers, and mixed so that the molar ratio (monomer (MV): monomer (MI)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved 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 2.3. A × 10 ⁴ resin X16 (copolymer) was obtained in a yield of 68%. This resin X16 has the following structural units.

Example 17 [Synthesis of Resin X17]
Monomer (MV) and monomer (M-J) are used as monomers and mixed so that the molar ratio (monomer (MV): monomer (M-J)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, and this resin was filtered twice, and the weight average molecular weight was 1.9. A × 10 ⁴ resin X17 (copolymer) was obtained in a yield of 66%. This resin X17 has the following structural units.

Example 18 [Synthesis of Resin X18]
Monomer (MV) and monomer (ML) are used as monomers, and mixed so that the molar ratio (monomer (MV): monomer (ML)) is 90:10. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved 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 1.8. A × 10 ⁴ resin X18 (copolymer) was obtained in a yield of 70%. This resin X18 has the following structural units.

[Synthesis of Resin A1]
As a monomer, a monomer (MM), a monomer (MN), a monomer (MD), a monomer (MO), and a monomer (MP) are used, and the molar ratio (monomer (MM) : Monomer (MN): monomer (MD): monomer (MO): monomer (MP)) were mixed so as to be 50: 5: 4: 33: 8. 1.2 mass times dioxane was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.8 mol% and 5.4 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved 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 4.7. × 10 ³ of the resin A1 (copolymer) was obtained in 71% yield. This resin A1 has the following structural units.

[Synthesis of Resin A2]
As a monomer, a monomer (MC), a monomer (MD), a monomer (ME), and a monomer (MF) are used, and the molar ratio (monomer (MC): monomer (MD) : Monomer (ME): monomer (MF)) was mixed so as to be 25: 25: 40: 10, and 1.5 mass times dioxane of the total monomer amount was added to obtain 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 77 ° 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 7.6. × 10 ³ of the resin A2 (copolymer) was obtained in 71% yield. This resin A2 has the following structural units.

[Synthesis of Resin A3]
Monomer (MM), monomer (MN), monomer (MD), monomer (MP) and monomer (MO) are used in a molar ratio (monomer (MM): monomer ( MN): monomer (MD): monomer (MP): monomer (MO)) are mixed at a ratio of 30: 14: 6: 20: 30, and this monomer is further mixed. The mixture was mixed with 1.5 mass times dioxane with respect to the total mass of all monomers. Into the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were respectively added to 1.00 mol% and 3.00 mol% with respect to the total number of moles of all monomers. It added so that it might become. This was polymerized by heating at 73 ° C. for about 5 hours. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin was filtered and collected. It is again dissolved in dioxane, poured into a mixed solvent of a large amount of methanol and water to precipitate the resin, and the precipitated resin is filtered and collected twice to perform reprecipitation purification, and the weight average molecular weight is 8 the copolymer is .1 × 10 ³ was obtained in a yield of 65%. This copolymer has the following structural units and is designated as resin A3.

[Synthesis of Resin A4]
Monomer (MT), monomer (MN), monomer (MD), monomer (MP) and monomer (MO) are used in a molar ratio (monomer (MT): monomer ( MN): monomer (MD): monomer (MP): monomer (MO)) are mixed at a ratio of 30: 14: 6: 20: 30, and this monomer is further mixed. The mixture was mixed with 1.5 mass times dioxane with respect to the total mass of all monomers. Into the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were respectively added to 1.00 mol% and 3.00 mol% with respect to the total number of moles of all monomers. It added so that it might become. This was polymerized by heating at 73 ° C. for about 5 hours. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin was filtered and collected. Again, it is dissolved in dioxane, poured into a large amount of methanol / water mixed solvent to precipitate the resin, and the precipitated resin is filtered and collected twice to perform reprecipitation purification, and the weight average molecular weight is 7 A copolymer of .8 × 10 ³ was obtained with a yield of 68%. This copolymer has the following structural units and is designated as resin A4.

[Synthesis of Resin A5]
Monomer (MT), monomer (MD) and monomer (MP) are used, and the molar ratio (monomer (MT): monomer (MD): monomer (MP)) is It mixed so that it might become 50:25:25, and also 1.5 mass times dioxane was mixed with respect to the total mass of all the monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. Then, this was heated at 80 ° C. for about 8 hours to carry out polymerization. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin was filtered and collected. Again, the obtained resin is dissolved in dioxane, poured into a large amount of methanol / water mixed solvent to precipitate the resin, and the precipitated resin is filtered and recovered three times for reprecipitation purification. A copolymer having a weight average molecular weight of about 9.2 × 10 ³ was obtained in a yield of 60%. This copolymer has a structural unit derived from each of the following monomers, and is designated as resin A5.

[Synthesis of Resin A6]
Monomer (M), monomer (N), monomer (D), monomer (P) and monomer (O) are mixed in a molar ratio [monomer (M): monomer (N): monomer (D): monomer (P): Monomer (O)] is mixed at a ratio of 30: 14: 6: 30: 20, and further, 1.5 mass times dioxane is mixed into this monomer mixture with respect to the total mass of all monomers. did. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators so as to be 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. Then, this was heated at 73 ° C. for about 5 hours to carry out polymerization. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin is filtered and recovered, dissolved again in dioxane, poured into a large amount of methanol / water mixed solvent to precipitate the resin, and the precipitated resin is filtered and recovered twice to perform reprecipitation. Purification was performed to obtain Resin A6 (copolymer) having a weight average molecular weight of about 7.9 × 10 ^{3 in} a yield of 60%. This resin A6 has the following structural units.

[Synthesis of Resin A7]
Monomer (M), monomer (N), monomer (U), monomer (P), and monomer (O) are in a molar ratio [monomer (M): monomer (U): monomer (D): monomer (P): Monomer (O)] is mixed at a ratio of 30: 14: 6: 30: 20, and further, 1.5 mass times dioxane is mixed into this monomer mixture with respect to the total mass of all monomers. did. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators so as to be 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. Then, this was heated at 73 ° C. for about 5 hours to carry out polymerization. Thereafter, the polymerization reaction solution was poured into a large amount of a mixed solvent of methanol and water (mass ratio methanol: water = 4: 1) to precipitate the resin. This resin is filtered and recovered, dissolved again in dioxane, poured into a large amount of methanol / water mixed solvent to precipitate the resin, and the precipitated resin is filtered and recovered twice to perform reprecipitation. After purification, a resin A7 (copolymer) having a weight average molecular weight of about 7.8 × 10 ³ was obtained in a yield of 62%. This resin A7 has the following structural units.

[Synthesis of Resin Z1]
Monomer (MA) and monomer (MB) are used as the monomers and mixed so that the molar ratio (monomer (MA): monomer (MB)) is 50:50. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 80 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in 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 9.3. A × 10 ³ resin Z1 (copolymer) was obtained in a yield of 55%. This resin Z1 has the following structural units.

<Preparation of resist composition>
Resins obtained in Examples 1 to 18 and Synthesis Examples 2 to 7;
Acid generator B1 shown below;
Basic compound C1 shown below;
Each was dissolved in the following solvent in the parts by mass shown in Table 3 and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a resist composition.

<Acid generator>
B1: Synthesis according to examples 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

<Manufacture of resist pattern>
An organic antireflective coating composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic reflective film having a thickness of 78 nm on the wafer. A prevention film was formed. Next, the resist composition was applied (spin coated) on the organic antireflection film so that the film thickness after drying (pre-baking) was 85 nm. After coating, the silicon wafer was pre-baked on a direct hot plate for 60 seconds at the temperature described in the “PB” column of Table 3 to form a composition layer. ArF excimer stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light) on a silicon wafer on which the composition layer is formed, and a contact hole pattern (hole pitch 100 nm) Using a mask for forming a hole diameter of 70 nm), the exposure amount was changed stepwise to perform exposure. Note that ultrapure water was used as the immersion medium. Note that ultrapure water was used as the immersion medium.
After the exposure, the silicon wafer was heated (post-exposure baking process) on a hot plate at a temperature described in the “PEB” column of Table 3 for 60 seconds. Next, this silicon wafer was subjected to paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution to obtain a resist pattern.

  In the resist pattern obtained after development, the exposure amount at which the hole diameter formed using the mask was 55 nm was defined as the effective sensitivity.

<Evaluation of mask error factor (MEF)>
In terms of effective sensitivity, the slope of a straight line when plotting the mask hole diameter on the horizontal axis and the hole diameter of each pattern on the vertical axis of a pattern formed with a mask having a hole diameter of 72 nm, 71 nm, 70 nm, 69 nm, and 68 nm, respectively. Calculated as MEF. The results are shown in Table 4.

<Defect evaluation>
The resist composition was applied (spin coated) to a 12-inch silicon wafer (substrate) so that the film thickness after drying was 0.15 μm. After coating, the composition layer was formed on the wafer by pre-baking (PB) for 60 seconds at a temperature shown in the PB column of Table 3 on a direct hot plate.
The wafer on which the composition layer was formed in this manner was subjected to water rinsing for 60 seconds using a developing machine [ACT-12; manufactured by Tokyo Electron Ltd.].
Thereafter, the number of defects on the wafer was measured using a defect inspection apparatus [KLA-2360; manufactured by KLA Tencor]. The results are shown in Table 4.

The resist patterns obtained using the resist compositions of Examples 19 to 43 were able to produce resist patterns having excellent mask error factors. On the other hand, in the resist compositions of Comparative Examples 1 and 2, the mask error factor of the resulting resist pattern was poor.
In addition, the resist patterns obtained using the resist compositions of Examples 19 to 43 were good in that the number of defects generated was small as compared with the resist compositions of Comparative Examples 1 and 2.

  According to the resist composition of the present invention, a resist pattern excellent in mask error factor (MEF) can be produced. Further, the obtained resist pattern has a small number of defects. Therefore, the resist composition of the present invention is useful for fine processing of semiconductors.

Claims (12)

A resin having a structural unit (aa) represented by the formula (aa) and a structural unit (ab) represented by the formula (ab).

[In the formula (aa)
R ^aa1 represents a hydrogen atom or a methyl group.
R ^aa2 represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
R ^aa3 represents a fluorinated alkyl group having 1 to 6 carbon atoms.
R ^aa4 represents a group in which the bond [O—R ^aa4 ] to the oxygen atom is not ^broken by the action of an acid.
n ^aa1 represents 1 or 2; When n ^aa1 is 2, two R ^aa2 are the same or different, two R ^aa3 are the same or different, and two R ^aa4 are the same or different.
A ^aa1 represents an ^optionally substituted hydrocarbon group having 1 to 10 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

[In the formula (ab),
R ^ab1 represents a hydrogen atom or a methyl group.
A ^ab1 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
R ^ab2 represents an ^optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. Good. ] The resin according to claim 1, wherein A ^{ab1 in the} formula (ab) is an alkanediyl group having 1 to 6 carbon atoms. The resin according to claim 1, wherein A ^{ab1 in the} formula (ab) is an ethylene group. The resin according to any one of claims 1 to 3, wherein the structural unit represented by the formula (ab) is a structural unit represented by the formula (I).

[In the formula (I),
R ^ab1 and A ^ab1 represent the same meaning as described above.
A ¹⁵ represents a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a fluorine atom.
X ¹² represents a carbonyloxy group or an oxycarbonyl group.
A ¹⁶ represents a monovalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a fluorine atom.
However, A ¹⁵ or A ¹⁶ has a fluorine atom, the total number of carbon atoms of A ¹⁵ and A ¹⁶ is 16 or less. ] The formula A ¹⁵ of (I) is, according to claim 4 resin wherein the perfluoro alkanediyl group having 1 to 6 carbon atoms. Formula X ¹² of (I) is, * - CO-O - ( . * Is representative of a bond to A ¹⁵⁾ in which according to claim 4 or 5, wherein the resin. The resin according to any one of claims 4 to 6, wherein A ^{16 in the} formula (I) is a cyclohexyl group, a norbornyl group or an adamantyl group.   A resist composition comprising the resin according to claim 1 and an acid generator. The resist composition according to claim 8, wherein the acid generator is an acid generator 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 C1-C17 divalent aliphatic hydrocarbon group which may have a substituent, and the methylene group contained in the aliphatic hydrocarbon group is replaced with an oxygen atom or a carbonyl group. It may be.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the aliphatic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group or a carbonyl group. May be.
Z ⁺ represents an organic cation. ]   The resist composition according to claim 9, wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent.   The resist composition according to any one of claims 8 to 10, further comprising a resin that is insoluble or hardly soluble in an alkaline aqueous solution and becomes soluble in an alkaline aqueous solution by the action of an acid. (1) The process of apply | coating the resist composition in any one of Claims 8-11 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: