JP2012092300A - Compound, resin and resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new resin which enables a resist pattern of an excellent shape to be produced, a resist composition, etc.SOLUTION: [1] The resin has a structural unit represented by formula (a), wherein Arepresents an alkanediyl group, a single bond or the like; Arepresents an alkanediyl group or the like; Wand Wrepresent a 4-36C aliphatic ring; and s represents 1 or 2. [2] The resist composition includes the resin of [1] and an acid generator.

Description

  The present invention relates to a resin useful for a resist composition, a resist composition containing the resin, a novel compound capable of producing the resin, and the like.

  In recent years, an optical lithography technique using a short wavelength light such as an ArF excimer laser (wavelength: 193 nm) as an exposure source has been actively studied as a microfabrication technique for semiconductors. The resist composition used in such photolithography technology contains 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.

As such a resin, for example, Patent Document 1 describes a resin composed of the following structural units. Further, this document also describes a resist composition containing the resin.

JP 2005-331918 A

  Conventionally known resist compositions containing the above resins may not always satisfy the shape of the resist pattern obtained when attempting to produce a finer resist pattern.

［式（ａ）中、
Ｒ^１は、水素原子又はメチル基を表す。
Ａ^１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、単結合又は式（ａ−１）

（式（ａ−１）中、
ｔは０〜２の整数を表す。
Ａ¹⁰は、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基を表す。
Ａ¹¹は、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基を表し、ｔが２である場合、２つのＡ¹¹は互いに同一でも異なっていてもよい。
Ａ¹²は、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基又は単結合を表す。
Ｘ¹⁰及びＸ¹¹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し、ｓが２である場合、２つのＸ¹⁰はそれぞれ独立である。
ただし、Ａ¹⁰、Ａ¹¹、Ｘ¹⁰及びＸ¹¹の炭素数の合計は６以下である。
*1は環Ｗ^１との結合手、*2は酸素原子との結合手を表す。）
で表される基を表す。
Ａ^２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を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
環Ｗ^１及び環Ｗ^２は、それぞれ独立に、炭素数４〜３６の脂肪族環を表す。
ｓは、１又は２を表す。］
〔２〕前記式（ａ）のＡ^１が、単結合又は
*1−ＣＨ_２−ＣＯ−Ｏ−*2
（*1及び*2は、上記と同じ意味である。）
である、前記〔１〕記載の樹脂。
〔３〕前記式（ａ）のＡ^２が、
*3−Ｏ−ＣＨ_２−ＣＯ−Ｏ−*4又は
*3−ＣＯ−Ｏ−ＣＨ_２−ＣＯ−Ｏ−*4
（*3及び*4は、一方が環Ｗ^１との、他方が環Ｗ^２との結合である。）
である、前記〔１〕又は〔２〕記載の樹脂。
〔４〕前記式（ａ）の

で表される部分構造が、式（Ｗ^１−ａ）又は式（Ｗ^１−ｂ）で表される構造である、前記〔１〕〜〔３〕のいずれか記載の樹脂。

〔５〕前記式（ａ）の

で表される部分構造が、式（Ｗ^２−ａ）で表される構造である前記〔１〕〜〔４〕のいずれか記載の樹脂。

〔６〕さらに、式（ａ１−１）で表される構造単位及び式（ａ１−２）で表される構造単位からなる群より選ばれる少なくとも１種を有する前記〔１〕〜〔５〕のいずれか記載の樹脂。

［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。］
〔７〕前記〔１〕〜〔６〕のいずれか記載の樹脂と、酸発生剤と、溶剤とを含有するレジスト組成物。
〔８〕前記酸発生剤が、式（Ｂ１）で表される前記〔７〕記載のレジスト組成物。

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、２価の炭素数１〜１７の飽和炭化水素基を表し、該２価の飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８の脂肪族炭化水素基を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子、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。］
〔９〕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前記〔８〕記載のレジスト組成物。
〔１０〕（１）前記〔７〕〜〔９〕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、
（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。
〔１１〕式（ａ’）で表される化合物。

［式（ａ’）中、
Ｒ^１は、水素原子又はメチル基を表す。
Ａ^１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、単結合又は式（ａ−１）

（式（ａ−１）中、
ｔは０〜２の整数を表す。
Ａ¹⁰は、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基を表す。
Ａ¹¹は、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基を表し、ｔが２である場合、２つのＡ¹¹は互いに同一でも異なっていてもよい。
Ａ¹²は、置換基を有していてもよい炭素数１〜５の脂肪族炭化水素基又は単結合を表す。
Ｘ¹⁰及びＸ¹¹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し、ｓが２である場合、２つのＸ¹⁰はそれぞれ独立である。
ただし、Ａ¹⁰、Ａ¹¹、Ｘ¹⁰及びＸ¹¹の炭素数の合計は６以下である。
*1は環Ｗ^１との結合手、*2は酸素原子との結合手を表す。）
で表される基を表す。
Ａ^２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を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
環Ｗ^１及び環Ｗ^２は、それぞれ独立に、炭素数４〜３６の脂肪族環を表す。
ｓは、１又は２を表す。］ The present invention includes the following inventions.
[1] A resin having a structural unit represented by the formula (a).

[In the formula (a),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent, a single bond, or formula (a-1).

(In the formula (a-1),
t represents an integer of 0-2.
A ¹⁰ represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ¹¹ represents an optionally substituted aliphatic hydrocarbon group having 1 to 5 carbon atoms, and when t is 2, two A ¹¹ may be the same as or different from each other.
A ¹² represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent or a single bond.
X ¹⁰ and X ¹¹ represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group, and when s is 2, the two X ¹⁰ are independent of each other.
However, the total number of carbon atoms of A ¹⁰ , A ¹¹ , X ¹⁰ and X ¹¹ is 6 or less.
* 1 bond to ring W ^1, * 2 represents a bond to an oxygen atom. )
Represents a group represented by
A ² represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms, and the methylene group constituting the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
Ring W ¹ and ring W ² each independently represent an aliphatic ring having 4 to 36 carbon atoms.
s represents 1 or 2. ]
[2] A ^{1 in the} formula (a) is a single bond or
* 1 —CH ₂ —CO—O— * 2
(* 1 and * 2 have the same meaning as above.)
The resin according to the above [1].
[3] A ^{2 in the} formula (a) is
_{* 3-O-CH 2 -CO} -O- * 4 or
_{* 3-CO-O-CH} 2 -CO-O- * 4
(* 3 and * 4 are one bond with ring W ¹ and the other with ring W ^2. )
The resin according to the above [1] or [2].
[4] In the formula (a)

The resin according to any one of [1] to [3] above, wherein the partial structure represented by the formula is a structure represented by the formula (W ¹ -a) or the formula (W ¹ -b).

[5] In the formula (a)

In the partial structure represented has the formula (W 2 ^-a) wherein a structure represented by [1] to [4] or wherein the resin.

[6] The above [1] to [5], further comprising at least one selected from the group consisting of a structural unit represented by the formula (a1-1) and a structural unit represented by the formula (a1-2) Any resin.

[In the 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). To express.
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 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O— (k1 is as defined above).
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. ]
[7] A resist composition containing the resin according to any one of [1] to [6], an acid generator, and a solvent.
[8] The resist composition according to [7], wherein the acid generator is represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent saturated 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 constituting the aliphatic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group or a carbonyl group. May be.
Z ⁺ represents an organic cation. ]
[9] The resist composition according to [8], wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent.
[10] (1) A step of applying the resist composition according to any one of [7] to [9] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure,
(5) a step of developing the composition layer after heating;
A method for producing a resist pattern including:
[11] A compound represented by the formula (a ′).

[In the formula (a ′),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent, a single bond, or formula (a-1).

(In the formula (a-1),
t represents an integer of 0-2.
A ¹⁰ represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ¹¹ represents an optionally substituted aliphatic hydrocarbon group having 1 to 5 carbon atoms, and when t is 2, two A ¹¹ may be the same as or different from each other.
A ¹² represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent or a single bond.
X ¹⁰ and X ¹¹ represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group, and when s is 2, the two X ¹⁰ are independent of each other.
However, the total number of carbon atoms of A ¹⁰ , A ¹¹ , X ¹⁰ and X ¹¹ is 6 or less.
* 1 bond to ring W ^1, * 2 represents a bond to an oxygen atom. )
Represents a group represented by
A ² represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms, and the methylene group constituting the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
Ring W ¹ and ring W ² each independently represent an aliphatic ring having 4 to 36 carbon atoms.
s represents 1 or 2. ]

  According to the resin of the present invention, a resist composition capable of producing a resist pattern having an excellent shape can be provided.

The present invention relates to a resin having a structural unit represented by the formula (a) (hereinafter sometimes referred to as “structural unit (a)”) (hereinafter sometimes referred to as “resin (A)”), the resin ( A resist composition containing A) (hereinafter sometimes referred to as “the present resist composition”), a method for producing a resist pattern using the present resist composition, and a novel compound capable of deriving the structural unit are provided.
This resist composition can produce a resist pattern having a good shape due to the effect of the resin (A) containing the structural unit represented by the formula (a).

<Resin (A)>
The resin (A) has a structural unit (a).

First, A ¹ , A ² , ring W ¹ and ring W ² in formula (a) will be described with reference to specific examples.
A ¹ is an optionally substituted alkanediyl group having 1 to 6 carbon atoms, a single bond or a group represented by the formula (a-1) (hereinafter, “group (a-1)” .) The “C 1-6 alkanediyl group” is a methylene group, an ethylene group, a propanediyl group, a butanediyl group, a pentanediyl group, a hexanediyl group, etc., which may be linear or branched. Good. The “C1-C6 alkanediyl group having a substituent” is a group in which a hydrogen atom contained in an alkanediyl group is substituted with a monovalent group (substituent) other than a hydrogen atom. As the alkanediyl group substituted with a group, * —CH ₂ —CHOH—CH ₂ — *, * —CH ₂ —C (CF ₃ ) ₂ — *, * —C (CH ₃ ) (CH ₂ OH) — *, * —CH (CH ₂ CH ₃ ) —CF ₂ — * (two of the groups shown here have the same meaning as * 1 of the group (a-1) and the other is a group (a- This is the same as * 2 in 1). The group (a-1) is a divalent group containing an atom or an atomic group such as an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group, as in X ¹⁰ and X ¹¹ .

などが挙げられる（＊は結合手を表す）。 Of the groups (a-1), as the group wherein X ¹¹ is an oxygen atom,

(* Represents a bond).

などが挙げられる（＊は結合手を表す）。 Among the groups (a-1), as the group wherein X ¹¹ is a carbonyl group,

(* Represents a bond).

などが挙げられる（＊は結合手を表す）。 Of the groups (a-1), as the group wherein X ¹¹ is a carbonyloxy group,

(* Represents a bond).

などが挙げられる（＊は結合手を表す）。 Of the groups (a-1), as the group wherein X ¹¹ is an oxycarbonyl group,

(* Represents a bond).

The alkanediyl group and the group (a-1) of A ¹ have been described with specific examples. Among these, A ¹ is a single bond, * 1-CH ₂ —CO—O— * 2, * 1 —CH ₂ —CH ₂ —CO—O— * 2, * 1-CH ₂ —O—CO— * 2 and * 1—CH ₂ —CH ₂ —O—CO— * 2 are preferred, and a single bond and * 1 —CH ₂ —CO—O— * 2 is more preferable.

Specific examples of the “optionally substituted alkanediyl group having 1 to 6 carbon atoms” in A ² include the “alkanediyl group having 1 to 6 carbon atoms optionally having a substituent” in A ^1. Examples thereof include the same groups as those exemplified as “group”. The alkanediyl group A ² is a methylene group constituting it may be replaced by an oxygen atom or a carbonyl group. The group in which the methylene group is replaced with an oxygen atom or a carbonyl group is the group already exemplified as the group (a-1) (provided that one of * 1 and * 2 in the specific examples of the group (a-1) is The bond to ring W ¹ (* 3) and the other to ring W ² (* 4))), * 3-O- * 4, * 3-O-CO- * 4, * 3-CO-O- * 4, * 3-O-CH like 2 -CO-O- * 4 and _{* 3-CO-O-CH} 2 -CO-O- * 4 can be cited. Among them, the ^{A 2, * 3-O-} CO- * 4, * 3-O-CH 2 -CO-O- * 4 and _{* 3-CO-O-CH} 2 -CO-O- * 4 is * 3-O—CH ₂ —CO—O— * 4 and * 3-CO—O—CH ₂ —CO—O— * 4 are more preferable. In addition, * 3 and * 4 of the group shown here have the same meaning as described above.

Ring W ¹ and ring W ² each independently represent an aliphatic ring having 4 to 36 carbon atoms. The aliphatic ring preferably has 5 to 24 carbon atoms, more preferably 6 to 18 carbon atoms. Examples of the aliphatic ring include an adamantane ring, a cyclohexane ring, a norbornane ring, a norbornene ring, and a ring in which two or more of these rings are condensed.

で表される部分構造が、

でそれぞれ表される構造が好ましく、式（Ｗ^１−ａ）又は式（Ｗ^１−ｂ）で表される構造がより好ましい。 Ring W ¹ is preferably an adamantane ring and is of formula (a)

The partial structure represented by

Are preferable, and a structure represented by the formula (W ¹ -a) or the formula (W ¹ -b) is more preferable.

で表される部分構造が、

でそれぞれ表される構造が好ましく、式（Ｗ^２−ａ）で表される構造がより好ましい。 Ring W ² is preferably an adamantane ring and a cyclohexane ring, of formula (a)

The partial structure represented by

And the structure represented by the formula (W ² -a) is more preferable.

また、上記の式（ａ−１）〜式（ａ−１０）でそれぞれ表される構造単位（ａ）の部分構造Ｍ（Ｒ^１＝メチル基）を、部分構造Ａ（Ｒ^１＝水素原子）に置き換えたものも、構造単位（ａ）の具体例として挙げることができる。

以上の構造単位（ａ）の具体例のうち、環Ｗ^１がアダマンタン環であり、環Ｗ^２がアダマンタン環又はシクロヘキサン環である、式（ａ−１）〜式（ａ−４）、式（ａ−７）〜式（ａ−８）でそれぞれ表される構造単位（ａ）がより好ましい。 As the structural unit (a), for example, those represented by the following formulas (a-1) to (a-10) are preferable.

Further, the partial structure M (R ¹ = methyl group) of the structural unit (a) represented by each of the above formulas (a-1) to (a-10) is converted into a partial structure A (R ¹ = hydrogen atom). Those replaced with can also be given as specific examples of the structural unit (a).

Among the specific examples of the structural unit (a), the ring W ¹ is an adamantane ring, and the ring W ² is an adamantane ring or a cyclohexane ring. The formulas (a-1) to (a-4) and ( The structural unit (a) represented by each of a-7) to formula (a-8) is more preferred.

（式（ａ’）中、Ａ^１、Ａ^２、環Ｗ^１、環Ｗ^２及びｓは上記と同じ意味を表す。） The structural unit (a) is derived from a compound represented by the following formula (a ′) (hereinafter sometimes referred to as “compound (a ′)”). This compound (a ′) is a novel and useful compound capable of deriving the structural unit (a), and this compound (a ′) is also included in the present invention.

(In formula (a ′), A ¹ , A ² , ring W ¹ , ring W ² and s represent the same meaning as described above.)

The production method of compound (a ′) is a compound represented by formula (aI) (hereinafter sometimes referred to as “compound (aI)”. In this compound (aI), A ¹ is a single bond, and A ² is * 3—O—CH ₂ —CO—O— * 4, which corresponds to the compound (a ′)).

Ｘ^１及びＸ^２は、それぞれ独立に、ハロゲン原子を表す。ハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子が挙げられ、塩素原子が好ましい。
式（ａＩ−ａ）で表される化合物は、所望の環Ｗ^２に応じた化合物を選択して用いることができる。環Ｗ^２が好ましいアダマンタン環又はシクロヘキサン環であるものとしては、例えば、１，４−シクロヘキサンジオール、１，３−アダマンタンジオール及び１，３，５−アダマンタントリオールなどが挙げられる。
式（ａ１−ｂ）で表される化合物としては、クロロアセチルクロリド及びブロモアセチルクロリドなどが挙げられる。これらは市場から容易に入手することができる。 First, the compound represented by the formula (aI-a) and the compound represented by the formula (aI-b) are reacted in the presence of a basic catalyst to represent the compound represented by the formula (aI-c). To obtain a compound. This reaction is preferably performed in a solvent such as tetrahydrofuran. As the basic catalyst, pyridine or the like is used.

X ¹ and X ² each independently represent a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a chlorine atom is preferable.
As the compound represented by the formula (aI-a), a compound corresponding to the desired ring W ² can be selected and used. Examples of ring W ^{2 that} is preferably an adamantane ring or a cyclohexane ring include 1,4-cyclohexanediol, 1,3-adamantanediol, 1,3,5-adamantanetriol, and the like.
Examples of the compound represented by the formula (a1-b) include chloroacetyl chloride and bromoacetyl chloride. These can be easily obtained from the market.

式（ａＩ−ｄ）で表される化合物も所望の環Ｗ^１に応じた化合物を選択して用いることができる。このような化合物としては例えば、３−ヒドロキシ−１−アダマンタンカルボン酸などが挙げられる。なお、式（ａＩ−ｄ）で表される化合物における、

で示される部分構造は、環Ｗ^１の脂肪族環を構成するメチレン基の１つがカルボニル基に置き換わった構造であることを示す。 Next, the compound represented by the formula (aI-c) and the compound represented by the formula (aI-d) are reacted in the presence of a catalyst, thereby being represented by the formula (aI-e). A compound is obtained. This reaction is preferably performed in a solvent such as dimethylformamide. As the catalyst, potassium carbonate, potassium iodide and the like are used.

As the compound represented by the formula (aI-d), a compound corresponding to the desired ring W ¹ can be selected and used. Examples of such a compound include 3-hydroxy-1-adamantanecarboxylic acid. In the compound represented by formula (aI-d),

The partial structure shown by shows that ^one of the methylene groups constituting the aliphatic ring of the ring W ¹ is replaced with a carbonyl group.

Next, the compound represented by the formula (aI-e) is obtained by reducing the compound represented by the formula (aI-e). This reaction is preferably performed in a solvent such as acetonitrile. For such reduction, a reducing agent such as sodium borohydride is used.

式（ａＩ−ｇ）で表される化合物としては、メタクリル酸クロリド及びアクリル酸クロリドなどが挙げられる。 Finally, the target compound (aI) is obtained by reacting the compound represented by the formula (aI-f) with the compound represented by the formula (aI-g) in the presence of a catalyst. The reaction is preferably performed in a solvent such as tetrahydrofuran. Examples of the catalyst include N-methylpyrrolidine.

Examples of the compound represented by the formula (aI-g) include methacrylic acid chloride and acrylic acid chloride.

Here, specific examples of the compound (a ′) include the following compounds.

  The content ratio of the structural unit (a) to the total structural unit (100 mol%) of the resin (A) is preferably in the range of 1 to 60 mol%, more preferably in the range of 2 to 55 mol%, and 3 to 50 mol%. Is more preferable, and the range of 3 to 30 mol% is more preferable. The resin (A) having the structural unit (a) in such a content ratio is a compound (a ′) that derives the structural unit (a) with respect to the total molar amount of all monomers used in the production of the resin (A). ) May be adjusted. Specifically, in order to produce the resin (A), the amount of the compound (a ′) used is preferably in the range of 1 to 60 mol% with respect to the total monomer amount (100 mol%). More preferably in the range of 55 mol%, still more preferably in the range of 3-50 mol%, and even more preferably in the range of 3-30 mol%. The resin (A) preferably has other structural units in addition to the structural unit (a), and the structural units other than the structural unit (a) will be described later.

  The resin (A) is preferably insoluble or hardly soluble in an alkaline aqueous solution and has a characteristic of being converted into a resin that is soluble in an alkaline aqueous solution by the action of an acid (hereinafter sometimes referred to as “acidic action characteristic”). . As used herein, “being soluble in an alkaline aqueous solution by the action of an acid” means insoluble or hardly soluble in an alkaline aqueous solution before contact with an acid, but becomes soluble in an alkaline aqueous solution after contact with an acid. Means that.

  In the various compounds shown in this specification, a functional group (group) may be shown, but a common group is defined here. In such a definition, the numerical value attached to “C” indicates the number of carbon atoms of each group.

  In the present specification, the “hydrocarbon group” refers to an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group is further classified into a chain type and an alicyclic group (a chain hydrocarbon group and an alicyclic hydrocarbon group). Unless specifically limited, the following “aliphatic hydrocarbon group” includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aliphatic hydrocarbon group in which these are combined.

The monovalent one of the chain hydrocarbon groups is typically an alkyl group, and examples of the alkyl group include a methyl group (C ₁ ), an ethyl group (C ₂ ), a propyl group (C ₃ ), and butyl. Group (C ₄ ), pentyl group (C ₅ ), hexyl group (C ₆ ), 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 ), octadecyl group (C ₁₈ ) and the like. The alkyl group shown here may be linear or branched. In addition, the chain hydrocarbon group may include a carbon-carbon unsaturated bond in a part of the alkyl group exemplified here unless otherwise limited. Of the divalent aliphatic hydrocarbon groups, the divalent chain hydrocarbon group typically corresponds to an alkanediyl group obtained by removing one hydrogen atom from the alkyl group shown here.

などが挙げられる。 A monovalent thing in an alicyclic hydrocarbon group is the group which removed one hydrogen atom from the alicyclic hydrocarbon, for example. The alicyclic hydrocarbon group may be an unsaturated group containing about one carbon-carbon unsaturated bond or a saturated group containing no carbon-carbon unsaturated bond. The hydrocarbon group is preferably a saturated alicyclic hydrocarbon group. The alicyclic hydrocarbon group may be monocyclic or polycyclic. Here, the alicyclic hydrocarbon before removing a hydrogen atom is illustrated. Monocyclic alicyclic hydrocarbons are typically cycloalkanes, for example
Cyclopropane (C ₃ ) represented by the formula (KA-1),
Cyclobutane (C ₄ ) represented by the formula (KA-2),
Cyclopentane (C ₅ ) represented by the formula (KA-3),
Cyclohexane (C ₆ ) represented by the formula (KA-4),
Formula cycloheptane represented by _{(KA-5) (C 7} ),
Cyclooctane (C ₈ ) represented by the formula (KA-6), and
Cyclododecane (C ₁₂ ) represented by the formula (KA-7)

Etc.

などが挙げられる。なお、ここに示した脂環式炭化水素を場合により、「式（ＫＡ−１）〜式（ＫＡ−２２）の脂環式炭化水素」という。
２価の脂環式炭化水素基とは、式（ＫＡ−１）〜式（ＫＡ−２２）の脂環式炭化水素から水素原子を２個取り去った基が挙げられる。 Examples of polycyclic alicyclic hydrocarbons include:
Bicyclo [2.2.1] heptane represented by formula (KA-8) (hereinafter sometimes referred to as “norbornane”) (C ₇ ),
Adamantane (C ₁₀ ) represented by the formula (KA-9),
An alicyclic hydrocarbon (C ₁₀ ) represented by the formula (KA- ₁₀ ),
An alicyclic hydrocarbon (C ₁₄ ) represented by the formula (KA-11),
An alicyclic hydrocarbon (C ₁₇ ) represented by the formula (KA-12),
An alicyclic hydrocarbon (C ₁₀ ) represented by the formula (KA-13),
An alicyclic hydrocarbon (C ₁₁ ) represented by the formula (KA-14);
An alicyclic hydrocarbon (C ₁₅ ) represented by the formula (KA- ₁₅ ),
An alicyclic hydrocarbon (C ₁₂ ) represented by the formula (KA-16),
An alicyclic hydrocarbon (C ₁₄ ) represented by the formula (KA-17),
An alicyclic hydrocarbon (C ₁₅ ) represented by the formula (KA-18),
An alicyclic hydrocarbon (C ₁₇ ) represented by the formula (KA-19),
An alicyclic hydrocarbon (C ₉ ) represented by the formula (KA-20),
An alicyclic hydrocarbon (C ₈ ) represented by the formula (KA-21) and
Alicyclic hydrocarbon (C ₁₀ ) represented by the formula (KA-22)

Etc. In addition, the alicyclic hydrocarbon shown here is sometimes called "alicyclic hydrocarbon of formula (KA-1) to formula (KA-22)".
Examples of the divalent alicyclic hydrocarbon group include groups in which two hydrogen atoms have been removed from the alicyclic hydrocarbon of the formula (KA-1) to the formula (KA-22).

Next, the aromatic hydrocarbon group will be described. In the present specification, among aromatic hydrocarbon groups, the monovalent aromatic hydrocarbon group 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 ). be able to. The divalent aromatic hydrocarbon group is an arylene group obtained by further removing one hydrogen atom from the monovalent aromatic hydrocarbon group.

  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 ). The alkoxy group may be linear or branched.
Examples of the acyl group include acetyl group (C ₂ ), propionyl group (C ₃ ), butyryl group (C ₄ ), valyl group (C ₅ ), hexylcarbonyl group (C ₇ ), heptylcarbonyl group (C ₇ ), octyl In addition to those in which an alkyl group such as a carbonyl group (C ₉ ), decylcarbonyl group (C ₁₁ ) and dodecylcarbonyl group (C ₁₂ ) is bonded to a carbonyl group, an aryl group such as a benzoyl group (C ₇ ) The thing couple | bonded with the carbonyl group is mentioned. Among the 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 in the above-described aromatic hydrocarbon group, and examples of the aryloxy group include those in which the 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 also have a substituent. Examples of the substituent include a halogen atom, an alkoxy group, an acyl group, an alkyl group, and an aryloxy group. The alkyl group is the same as that exemplified as the chain-type aliphatic hydrocarbon group, and those other than the alkyl group include those exemplified as the substituent of the aliphatic hydrocarbon group.

式（１）中、
Ｒ^a1、Ｒ^a2及びＲ^a3は、それぞれ独立に、炭素数１〜２０の脂肪族炭化水素基を表し、Ｒ^a1及びＲ^a2は互いに結合して、それらが結合する炭素原子とともに炭素数３〜２０の環を形成してもよい。Ｒ^a1及びＲ^a2が互いに結合して形成される環又は該脂肪族炭化水素基を構成するメチレン基は、酸素原子、硫黄原子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。 <Structural unit (a1)>
The resin (A) having acid action characteristics is a structural unit having an acid labile group (however, it is different from the structural unit (a), and is hereinafter referred to as “structural unit (a1)” in some cases. In the description, the monomer capable of deriving the structural unit (a1) is sometimes referred to as “monomer (a1)” together with the structural unit (a). The acid labile group refers to a hydrophilic group protected by a protecting group that can be removed by contact with an acid. The resin having the structural unit (a1) has a characteristic that when it comes into contact with an acid, the protecting group is eliminated and the resin becomes soluble in an alkaline aqueous solution. Examples of the hydrophilic group include a hydroxy group and a carboxy group, and a carboxy group is preferable. In the case where the hydrophilic group is a carboxy group, the acid labile group is a group in which the hydrogen atom of the carboxy group is replaced with an organic residue, and the atom of the organic residue bonded to the oxygen atom is a tertiary carbon atom. Is mentioned. Among such acid labile groups, preferred acid labile groups are, for example, groups represented by the following formula (1) (hereinafter sometimes referred to as “acid labile groups (1)”).

In formula (1),
R ^a1 , R ^a2 and R ^a3 each independently represent an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and R ^a1 and R ^a2 are bonded to each other and together with the carbon atom to which they are bonded, Twenty rings may be formed. The ring formed by combining R ^a1 and R ^a2 or the methylene group constituting 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 preferably an alkyl group or an alicyclic hydrocarbon group. The specific example of this alkyl group is a C1-C20 thing among the alkyl groups already illustrated.
Examples of the alicyclic hydrocarbon group represented by R ^{a1 to} R ^a3 include alicyclic hydrocarbon groups having 20 or less carbon atoms among those already exemplified. The alicyclic hydrocarbon group preferably has 1 to 16 carbon atoms.

The case where R ^a1 and R ^a2 are bonded to each other to form a ring is a case where a group represented by —C (R ^a1 ) (R ^a2 ) (R ^a3 ) is a group shown below. The number of carbon atoms in such a ring is preferably in the range of 3-12.

Examples of the acid labile group (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are all alkyl groups, and one of these alkyl groups is tert-butoxy A carbonyl group), a 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are bonded to each other, and together with the carbon atom to which they are bonded, an adamantyl ring is formed; R ^a3 is an alkyl group) and 1- (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, R ^a3 is an adamantyl group) A certain 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の炭化水素基を表し、Ｒ^b2及びＲ^b3が互いに結合して、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の環を形成してもよい。Ｒ^b2及びＲ^b3は互いに結合して形成される環及び該炭化水素基を構成するメチレン基は、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。 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, a preferred acid labile group is, for example, a group represented by the following formula (2) (hereinafter sometimes referred to as “acid labile group (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, R ^b3 represents a hydrocarbon group having 1 to 20 carbon atoms, R ^b2 And R ^b3 may be bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom and the oxygen atom to which they are bonded. The ring formed by bonding R ^b2 and R ^b3 and the methylene group constituting the hydrocarbon group may 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 either an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and specific examples thereof include those already exemplified as long as the upper limit of the carbon number is 20 or less. As the acid labile group (2), at least one of R ^b1 and R ^b2 is preferably a hydrogen atom.

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

  The structural unit (a1) is preferably derived from a structural unit derived from a monomer having this acid labile group and a carbon-carbon double bond, more preferably from a (meth) acrylic monomer having an acid labile group. Structural unit. The structural unit (a1) may have both an acid labile group (1) and an acid labile group (2). Among the acid labile groups (1) and acid labile groups (2), And the structural unit (a1) having any of them, and the structural unit (a1) having an acid labile group (1) is more preferable.

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

  As described above, among the (meth) acrylic monomers having an acid labile group (1), the monomer (a1) in which the acid labile group (1) has an alicyclic hydrocarbon structure having 5 to 20 carbon atoms. Is preferred. The resin (A) obtained by polymerizing the monomer (a1) having such a sterically bulky alicyclic hydrocarbon group is produced by using the resist composition containing the resin (A). In this case, the resist pattern can be manufactured with a better resolution.

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は上記と同じ意味であり、*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^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。 Among the structural units (a1) containing the acid labile group (1) having an alicyclic hydrocarbon structure, the structural unit represented by the formula (a1-1) (hereinafter referred to as “structural unit (a1-1)” Or a structural unit represented by the formula (a1-2) (hereinafter sometimes referred to as “structural unit (a1-2)”). Resin (A) which has an acid action characteristic may have these individually, and may have 2 or more types.

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). To express.
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 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O— (k1 has the same meaning as described above, and * represents a bond to a carbonyl group). .
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.

L ^a1 and L ^a2 are preferably an oxygen atom or a group represented by ^* 1—O— (CH ₂ ) _k1 —CO—O—, wherein k1 is 1 to 4, and an oxygen atom or ^* —O—CH _2- CO-O- is more preferable, and an oxygen atom is particularly preferable.
R ^a4 and R ^a5 are preferably methyl groups.
Of the aliphatic hydrocarbon groups represented by R ^a6 and R ^a7 , an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms is preferable. 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.
n2 is preferably an integer of 0 to 2, more preferably 0 or 1.

Examples of the structural unit (a1-1) include the following.

ここに示す式（ａ１−１−１）〜式（ａ１−１−３８）でそれぞれ表される構造単位（ａ１−１）において、構造単位（ａ）の具体例の場合と同様に、部分構造Ｍを部分構造Ａに置き換えたものも構造単位（ａ１−１）の具体例として挙げることができる。

In the structural unit (a1-1) represented by each of the formulas (a1-1-1) to (a1-1-38) shown here, as in the case of the specific example of the structural unit (a), the partial structure What replaced M with the partial structure A can also be mentioned as a specific example of a structural unit (a1-1).

  As the structural unit (a1-1), the structural unit (a1-1) represented by each of the formula (a1-1-1), the formula (a1-1-2) and the formula (a1-1-3), and What substituted the partial structure M of these structural units (a1-1) by the partial structure A is preferable, and the formula (a1-1-1), the formula (a1-1-2), and the formula (a1-1-3) are preferable. Are more preferable, and the structural unit (a1-1) represented by the formula (a1-1-1) or the formula (a1-1-2) is more preferable. In addition, the resin (A) having these preferred structural units (a1-1) is obtained by producing 2-methyladamantan-2-yl (meth) acrylate, 2-ethyladamantan-2-yl when producing the resin (A). Ir (meth) acrylate or 2-isopropyladamantan-2-yl (meth) acrylate may be used as the monomer (a1).

式（ａ１−２−１）〜式（ａ１−２−１２）でそれぞれ表される構造単位（ａ１−２）において、構造単位（ａ１−１）の例示と同様に、部分構造Ｍを部分構造Ａに置き換えたものも構造単位（ａ１−２）として挙げることができる。
なかでも、式（ａ１−２−１）、式（ａ１−２−２）、式（ａ１−２−４）及び式（ａ１−２−５）でそれぞれ表される構造単位（ａ１−２）、あるいは、これらの構造単位（ａ１−２）の部分構造Ｍが部分構造Ａに置き換えられたものがより好ましく、式（ａ１−２−４）で表される構造単位（ａ１−２）及び式（ａ１−２−４）で表される構造単位の部分構造Ｍが部分構造Ａに置き換えられたものがより好ましい。構造単位（ａ１−２）を有する樹脂（Ａ）を製造するためには、１−エチルシクロヘキサン−１−イル（メタ）アクリレートをモノマー（ａ１）として用いて、樹脂（Ａ）を製造すればよい。 Examples of the structural unit (a1-2) include the following.

In the structural unit (a1-2) represented by each of the formulas (a1-2-1) to (a1-2-12), the partial structure M is converted into a partial structure in the same manner as the structural unit (a1-1). Those substituted with A can also be exemplified as the structural unit (a1-2).
Among them, the structural unit (a1-2) represented by each of the formula (a1-2-1), the formula (a1-2-2), the formula (a1-2-4), and the formula (a1-2-5) Alternatively, those in which the partial structure M of the structural unit (a1-2) is replaced with the partial structure A are more preferable, and the structural unit (a1-2) and the formula represented by the formula (a1-2-4) More preferably, the partial structure M of the structural unit represented by (a1-2-4) is replaced with the partial structure A. In order to produce the resin (A) having the structural unit (a1-2), the resin (A) may be produced using 1-ethylcyclohexane-1-yl (meth) acrylate as the monomer (a1). .

  When the resin (A) has the structural unit (a1-1) and / or the structural unit (a1-2) as the structural unit (a1), when the total structural unit of the resin (A) is 100 mol%, these The total content of the structural units is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, still more preferably 20 to 85 mol%, and even more preferably 25 to 60 mol%. preferable. In order to bring the total content of the structural unit (a1-1) and / or the structural unit (a1-2) into such a range, when the resin (A) is produced, these structures with respect to all monomers are used. What is necessary is just to adjust the total usage-amount of the monomer (a1) which derives a unit (a1). Specifically, the monomer (a1) for deriving the structural unit (a1-1) and / or the structural unit (a1-2) with respect to the total monomer amount (100 mol%) in order to produce the resin (A). Is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%, still more preferably in the range of 20 to 85 mol%, and in the range of 25 to 60 mol%. Is more preferable.

  In addition to the structural unit (a1-1) and the structural unit (a1-2), the resin (A) has a structural unit (a1) [another structural unit (a1)] having an acid labile group. May be. Hereinafter, the structural unit (a1) other than the structural unit (a1-1) and the structural unit (a1-2) will be described by showing the monomer (a1) that derives the structural unit (a1).

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、カルボキシル基、シアノ基又は−ＣＯＯＲ^a13を表す。
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、ヒドロキシ基で置換されていてもよく、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。なお、Ｒ^a9のアルコキシカルボニル基の中では、Ｒ^a13として炭素数１〜８のアルキル基又は炭素数３〜２０の脂環式炭化水素基が好ましい。
Ｒ^a10、Ｒ^a11及びＲ^a12（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が互いに結合して、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、ヒドロキシ基などで置換されていてもよく、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。 Such other structural unit (a1) is derived from, for example, a monomer (a1) having a norbornene ring represented by the following formula (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”). Can be mentioned.

In formula (a1-3),
R ^a9 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms which may have a hydroxy group, a carboxyl group, a cyano group or —COOR ^a13 .
R ^a13 represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group, and constitutes the aliphatic hydrocarbon group The methylene group may be replaced with an oxygen atom or a carbonyl group. Of the alkoxycarbonyl groups represented by R ^a9 , R ^a13 is preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms.
R ^a10 , R ^a11 and R ^a12 (R ^{a10 to} R ^a12 ) each independently represent 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 is bonded, a ring having 3 to 20 carbon atoms is formed, and the hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and the aliphatic hydrocarbon group May be replaced with an oxygen atom or a carbonyl group.

Examples of the alkyl group having a R ^a9 hydroxy group include a hydroxymethyl group and a 2-hydroxyethyl group.
Examples of the aliphatic hydrocarbon group of R ^{a10 to} R ^a12 include a chain hydrocarbon group (for example, an alkyl group) and an alicyclic hydrocarbon group, and include those already exemplified in the range of 20 or less carbon atoms. .
The ring formed by combining R ^a10 and R ^a11 with each other is preferably an aliphatic ring, more preferably a cyclohexane ring or an adamantane ring.

^Examples of —COOR ^a13 for R ^a9 include groups in which a carbonyl group is further bonded to the alkoxy group already exemplified, such as a methoxycarbonyl group (C ₂ ) and an ethoxycarbonyl group (C ₃ ).

  Examples of the monomer (a1-3) include, for example, 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene-2-carboxylic acid 1- Methyl cyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1- (4-methylcyclohexyl) ) -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- (1-adamantyl) -1-methyl 5-norbornene-2-carboxylate Such as chill, and the like.

  The resin (A) produced using the monomer (a1-3) contains a sterically bulky structural unit (a1) derived from the monomer (a1-3). Therefore, if a resist pattern is produced using the present resist composition containing the resin (A) having the structural unit (a1), the resist pattern can be obtained with better resolution. Furthermore, since the rigid norbornane ring can be introduced into the main chain of the resin (A) by producing using the monomer (a1-3), the resist composition containing the resin (A) has a resistance to dry etching. There is a tendency that an excellent resist pattern is easily obtained.

  As described above, the monomer (a1) relative to the total structural unit (100 mol%) of the resin (A) is that the resist pattern can be produced with good resolution and that a resist pattern excellent in dry etching resistance can be easily obtained. The content of the structural unit (a1) derived from -3) 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%.

  The monomer (a1-3) capable of deriving the structural unit (a1) having the acid labile group (1) has been described. Next, the monomer (a1) capable of deriving the structural unit (a1) having the acid labile group (2) ), That is, specific examples of the monomer (a1) having an acid labile group (2).

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、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は同一であっても異なっていてもよい。
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のアシルオキシ基に置換されていてもよい。Ｘ^a2の脂肪族炭化水素基としては、鎖式炭化水素基であると好ましく、アルカンジイル基であるとより好ましい。該脂肪族炭化水素基を構成するメチレン基は、酸素原子、硫黄原子、カルボニル基、スルホニル基又は−Ｎ（Ｒ^ｃ）−で示される基に置き換わっていてもよい。ここで、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、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る。該炭化水素基は、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 (a1) having an acid labile group (2) include a monomer (a1) represented by the following formula (a1-4) (hereinafter, sometimes referred to as “monomer (a1-4)”). Is mentioned.

In formula (a1-4),
R ^a32 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or 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 may be 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 an acyl group having 2 to 4 carbon atoms and an acyloxy group having 2 to 4 carbon atoms. The aliphatic hydrocarbon group for X ^a2 is preferably a chain hydrocarbon group, and more preferably an alkanediyl group. The methylene group constituting 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 ) —. Here, 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, preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrocarbon 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. It may be.

R ^a32, R ^a33, specific examples of R ^a34, R ^a35 and X ^a2 of the formula (a1-4).
Of the “alkyl group ^optionally having a halogen atom” for R ^a32 , the alkyl group includes those already exemplified in the range of 1 to 6 carbon atoms. As the alkyl group having a halogen atom, a hydrogen atom contained in the alkyl group is replaced with a halogen atom. Specific examples of the alkyl group having a halogen atom include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl. Group, perfluorohexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group and the like.
Specific examples of the halogen atom, alkoxy group and acyl group for R ^a32 and R ^a33 include those already exemplified.
Hydrocarbon group R ^a34 and R ^a35 are chain hydrocarbon groups may be either an alicyclic hydrocarbon group and aromatic hydrocarbon group. Specific examples thereof include those already exemplified in each carbon number range. 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. As the formula hydrocarbon group, a cyclohexyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, an isobornyl group, and the like are preferable. The aromatic hydrocarbon group is phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl. Group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl are preferred.

When R ^a32 and R ^a33 are alkyl groups, an alkyl group having 1 to 4 carbon atoms is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.
As the alkoxy group for R ^a33 , a methoxy group or an ethoxy group is more preferable, and a methoxy group is particularly preferable.

As described above, in X ^a2 and Y ^a3 , a hydrogen atom contained therein may be substituted with a halogen atom, a hydroxy group, or the like. When a hydrogen atom is substituted in this way, the substituent is A hydroxy group is preferred.

As a monomer (a1-4), the following are mentioned, for example. In the following examples, the hydrogen atom contained in the benzene ring may be substituted with a substituent (R ^a33 ).

  When the resin (A) has the structural unit (a1) derived from the monomer (a1-4), the content is 10 to 95 mol with respect to the total structural unit (100 mol%) of the resin (A). % Range is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is more preferable.

式（ａ１−５）中、
Ｒ³¹は、水素原子及びメチル基が好ましい。
Ｌ^１は、酸素原子が好ましい。
Ｌ^２及びＬ^３は、それぞれ独立に酸素原子又は硫黄原子である。Ｌ^２及びＬ^３は、一方が酸素原子、他方が硫黄原子であると好ましい。
ｓ１は、１が好ましい。
ｓ２は、０〜２の整数が好ましい。
Ｚ^１は、単結合又は炭素数１〜６のアルカンジイル基であり、該アルカンジイル基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。Ｚ^１としては、単結合又は−ＣＨ_２−ＣＯ−Ｏ−が好ましい。 As the monomer having an acid labile group (2), for example, a monomer (a1) represented by the formula (a1-5) (hereinafter sometimes referred to as “monomer (a1-5)”) may also be used.

In formula (a1-5),
R ³¹ is preferably a hydrogen atom or a methyl group.
L ¹ is preferably an oxygen atom.
L ² and L ³ are each independently an oxygen atom or a sulfur atom. One of L ² and L ³ is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s2 is preferably an integer of 0 to 2.
Z ¹ is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group constituting the alkanediyl group may be replaced with an oxygen atom or a carbonyl group. Z ¹ is preferably a single bond or —CH ₂ —CO—O—.

As a monomer (a1-5), the following monomers (a1) are mentioned, for example. Here, specific examples in which R ³¹ is a methyl group will be shown, but those in which this methyl group is replaced with a hydrogen atom are also specific examples of the monomer (a1-5).

  When the resin (A) has a structural unit (a1) derived from the monomer (a1-5), the content is 10 to 95 mol with respect to the total structural unit (100 mol%) of the resin (A). % Range is preferable, the range of 10 to 90 mol% is more preferable, the range of 10 to 85 mol% is more preferable, and the range of 10 to 70 mol% is more preferable.

<Acid stable structural unit>
As the resin (A) having acid action characteristics, in addition to the structural unit (a) and the structural unit (a1), a structural unit having no acid labile group (hereinafter, sometimes referred to as “acid-stable structural unit”) The monomer for deriving the acid-stable structural unit preferably has an “acid-stable monomer” in some cases.

  When the resin (A) has an acid stable structural unit, the content ratio of the acid stable structural unit may be determined based on the content ratio of the structural unit (a1). The ratio of the content ratio of the structural unit (a1) and the content ratio 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 structural unit (a1-1) is based on the total amount (100 mol%) of the structural unit (a1). The ratio 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.

  As the acid stable structural unit, those having a hydroxy group or a lactone ring are preferred. 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 containing a lactone ring (hereinafter sometimes referred to as “acid stable structural unit (a3)”) When the resist composition containing the resin (A) is applied to a substrate, the resin film (A) having the composition “)”) has a coating film formed on the substrate or a composition layer obtained from the coating film. It becomes easy to express excellent adhesiveness with the substrate, and this resist composition can produce a resist pattern with good resolution.

<Acid stable structural unit (a2)>
When the acid stable structural unit (a2) is introduced into the resin (A), a suitable acid stable structural unit is used depending on the type of exposure source when producing a resist pattern from the present resist composition containing the resin (A). (A2) can be selected. That is, when this resist composition is used for KrF excimer laser (wavelength: 248 nm) exposure, exposure with a high energy beam such as an electron beam or EUV light, a phenolic hydroxy group is used as the acid stable structural unit (a2). The acid-stable structural unit (a2-0) having is preferably introduced into the resin (A). When using short-wavelength ArF excimer laser (wavelength: 193 nm) exposure, an acid stable structural unit represented by the formula (a2-1) described later is introduced into the resin (A) as the acid stable structural unit (a2). It is preferable. Thus, each of the acid stable structural units (a2) possessed by the resin (A) can be selected according to the exposure source used for producing the resist pattern, but the acid stable structural units possessed by the resin (A) ( a2) may have only one type of acid stable structural unit (a2) suitable for the type of exposure source, and two or more types of acid stable structural unit (a2) suitable for the type of exposure source. Or an acid stable structural unit (a2) suitable for the type of exposure source and a combination of other acid stable structural units (a2).

式（ａ２−１）中、
Ｌ^a3は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−（ｋ２は１〜７の整数を表す。）を表し、＊はカルボニル基との結合手を表す。
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) include a structural unit 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 to a carbonyl group.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10.

L ^a3 is preferably an oxygen atom or a group represented by * —O— (CH ₂ ) _k2 —CO—O—, wherein k2 is an integer of 1 to 4, and more preferably an oxygen atom or * —O—CH ₂ —CO—O—, and more preferably an oxygen atom.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

As an acid stable structural unit (a2-1), the following are mentioned, for example.

ここに示す式（ａ２−１−１）〜式（ａ２−１−１７）でそれぞれ表される構造単位（ａ２−１）において、構造単位（ａ）の具体例と同様に、部分構造Ｍを部分構造Ａに置き換えたものも構造単位（ａ２−１）の具体例として挙げることができる。

In the structural unit (a2-1) represented by each of the formula (a2-1-1) to the formula (a2-1-17) shown here, as in the specific example of the structural unit (a), the partial structure M is Those replaced with the partial structure A can also be given as specific examples of the structural unit (a2-1).

  Among the exemplified acid stable structural units (a2-1), in the formula (a2-1-1), the formula (a2-1-2), the formula (a2-1-13), and the formula (a2-1-15) The structural unit (a2-1) represented respectively, and those in which the partial structure M of these structural units (a2-1) is replaced with the partial structure A are preferred, and are represented by the formulas (a2-1-1) and (a2- 1-2), structural units represented by the formula (a2-1-13) and the formula (a2-1-15), respectively, are more preferable. Resin (A) having these structural units (a2-1) is 3-hydroxyadamantan-1-yl (meth) acrylate, 3,5-dihydroxyadamantan-1-yl (meth) acrylate or (meth) acrylic acid 1- (3,5-dihydroxyadamantan-1-yloxycarbonyl) methyl may be used as an acid stable monomer for producing the resin (A).

  When the resin (A) has an acid stable structural unit (a2-1), the content ratio is preferably in the range of 3 to 40 mol% with respect to all the structural units (100 mol%) of the resin (A). The range of 3 to 35 mol% is more preferable, the range of 3 to 30 mol% is more preferable, and 3 to 15 mol% is particularly preferable.

式（ａ２−０）中、
Ｒ^a30は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^a31は互いに同一であっても異なってもよい。 <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 may be the same as or different from each other.

The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and 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.
As the alkoxy group for R ^a31, the same groups as those exemplified for R ^a33 in formula (a1-4) can be mentioned. Among these, 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.

ここに示す酸安定モノマー（ａ２−０）の具体例において、ベンゼン環に結合しているメチル基やエチル基を、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）の具体例である。 When the acid stable structural unit (a2-0) is exemplified by an acid stable monomer (hereinafter, sometimes referred to as “acid stable monomer (a2-0)”) from which the acid stable structural unit (a2-0) is derived, It is as follows.

In the specific examples of the acid stable monomer (a2-0) shown here, the methyl group and ethyl group bonded to the benzene ring are replaced with other substituents exemplified as R ^a31 , and the acid stable monomer (a2 -0).

  When the resin (A) is produced using such an 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 is used. It can also be used. For example, a phenolic hydroxy group protected with a protecting group capable of leaving with an acid is deprotected by contact with an acid, so that an acid-stable structural unit (a2-0) can be easily obtained from a polymer polymerized using the phenolic hydroxy group. A resin having a precursor structural unit can be produced. However, since the resin (A) may have a structural unit (a1) having an acid labile group as described above, a structural unit derived from a monomer in which a phenolic hydroxy group is protected with an appropriate protective group. When deprotecting, it is preferable to deprotect by contact with a base so that the acid labile group in the structural unit (a1) is not significantly impaired. As the protecting group to be deprotected by contact with a base, for example, an acetyl group is preferable. Examples of the base include 4-dimethylaminopyridine and triethylamine.

  Among the acid stable monomers (a2-0), 4-hydroxystyrene or 4-hydroxy-α-methylstyrene is particularly preferable. When the resin (A) is produced using 4-hydroxystyrene or 4-hydroxy-α-methylstyrene, it is preferable to use a resin in which a phenolic hydroxy group is protected with an appropriate protective group.

  When the 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 the structural units (100 mol%) of the resin (A). The range of 10-80 mol% is more preferable, and the range of 15-80 mol% is more preferable.

<Acid stable structural unit (a3)>
The lactone ring included in the acid stable structural unit (a3) may be monocyclic such as β-propiolactone ring, γ-butyrolactone ring and δ-valerolactone ring, and the 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.

  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 ( a-3) ”, and the compound represented by the formula (a3-3) may be referred to as“ acid-stable structural unit (a3-3) ”.

［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は互いに同一であっても異なってもよい。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）を表す。*はカルボニル基との結合手を表す。
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、互いに同一であっても異なってもよい。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）を表す。*はカルボニル基との結合手を表す。
Ｒ^a20は、水素原子又はメチル基を表す。
ｒ１は、０〜３の整数を表す。
Ｒ^a23は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表し、ｒ１が２以上の場合、複数のＲ^a23は、互いに同一であっても異なってもよい。］

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

In Formula (a3-1) to Formula (a3-3), specific examples of L ^{a4 to} La ⁶ are the same as those described for L ^a3 in Formula (a2-1).
L ^{a4 to} L ^a6 are each independently an oxygen atom or a group represented by * —O— (CH ₂ ) _k3 —CO—O— in which k3 is an integer of 1 to 4, preferably an oxygen atom or * —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 each independently preferably an integer of 0 to 2, more preferably 0 or 1.

Examples of the acid stable structural unit (a3-1) 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.

ここに示す式（ａ３−１−１）〜式（ａ３−１−１１）でそれぞれ表される構造単位（ａ３−１）、式（ａ３−２−１）〜式（ａ３−２−１１）でそれぞれ表される構造単位（ａ３−２）及び式（ａ３−３−１）〜式（ａ３−３−６）でそれぞれ表される構造単位（ａ３−３）において、構造単位（ａ）の例示と同様に、部分構造Ｍを部分構造Ａに置き換えたものも、各々構造単位（ａ３−１）、構造単位（ａ３−２）及び構造単位（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挙げたが、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）の具体例である。 Examples of the acid stable structural unit (a3-3) having a condensed ring of γ-butyrolactone ring and cyclohexane ring include the following.

Structural units (a3-1) and (a3-2-1) to (a3-2-11) represented by formulas (a3-1-1) to (a3-1-11) shown here, respectively In the structural unit (a3-2) and the structural unit (a3-3) represented by the formula (a3-3-1) to the formula (a3-3-6), respectively, Similarly to the examples, those in which the partial structure M is replaced with the partial structure A can also be given as specific examples of the structural unit (a3-1), the structural unit (a3-2), and the structural unit (a3-3). . Moreover, in this illustration, those having a methyl group as the substituents (R ^{a21 to} R ^a23 ) of the lactone ring are also mentioned, but those in which this methyl group is replaced with the above groups are also acid stable structural units ( This is a specific example of a3).

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) stabilized acid is derived from 2-oxoethyl 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 60 mol%, more preferably in the range of 5 to 50 mol%, and more preferably 10 to 40 mol based on the total structural unit (100 mol%) of the resin (A). % Range is more preferable, the range of 15-40 mol% is more preferable, and the range of 20-40 mol% is still more preferable.
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 (A). 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.

<Acid-stable monomer (a4)>
The resin (A) may have an acid stable structural unit other than the acid stable structural unit (a2) and the acid stable structural unit (a3). Such an acid stable structural unit will be described by showing an acid stable monomer capable of deriving the acid stable structural unit. Hereinafter, the acid stable monomer capable of deriving an acid stable structural unit other than the acid stable structural unit (a2) and the acid stable structural unit (a3) is sometimes referred to as “acid stable monomer (a4)”.

［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を表すか、或いはＲ^a25及びＲ^a26は互いに結合して−ＣＯ−Ｏ−ＣＯ−を形成する。
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を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。但し−ＣＯＯＲ^a27が酸不安定基となるものは除く（例えばＲ^a27は、第三級炭素原子が−Ｏ−と結合するものを含まない）〕 As this acid stable monomer (a4), maleic anhydride represented by the following formula (a4-1), itaconic anhydride represented by the following formula (a4-2), and the following formula (a4-3) And an acid-stable monomer having a norbornene ring represented by the formula (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 which may have a hydroxy group, a cyano group, a carboxy group or —COOR ^a27 , or R ^a25 and R ^{a26 a26} combine with each other to form —CO—O—CO—.
R ^a27 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. However, those in which —COOR ^a27 is an acid labile group are excluded (for example, R ^a27 does not include those in which a tertiary carbon atom is bonded to —O—).]

In R ^a25 and R ^a26 in formula (a4-3), 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 at least one acid-stable structural unit selected from the group consisting of structural units derived from, the total content is 2 to 40 moles with respect to all structural units (100 mole%) of the resin (A) % Range is preferable, 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。
Ｗ¹⁶は、置換基を有していてもよいスルトン環基を表す。］ Furthermore, examples of the acid stable monomer (a4) include an acid stable monomer having a sultone ring represented by the formula (a4-4) (hereinafter, sometimes referred to as “acid stable monomer (a4-4)”). Can be mentioned.

[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 ¹⁶ 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）に置き換わったものであり、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のアシルオキシ基からなる群より選ばれる。 The sultone ring contained in the sultone ring group is a methylene group constituting an alicyclic hydrocarbon in which two adjacent methylene groups are replaced with one oxygen atom and the other with a sulfonyl group. Things. 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 replaced 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, carbon It is selected from the group consisting of an alkoxycarbonyl group having 1 to 7 carbon atoms, an acyl group having 1 to 7 carbon atoms, and an acyloxy group having 1 to 8 carbon atoms.

As an acid stable monomer (a4-4), the following are mentioned, for example.

ここに示した酸安定モノマー（ａ４−４）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（ａ４−４）として挙げることができる。

In the acid-stable monomer (a4-4) shown here, those in which the partial structure M ′ is replaced with the partial structure A ′ can also be exemplified as the acid-stable monomer (a4-4).

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

As the acid stable monomer (a4), for example, an acid stable monomer having a fluorine atom as shown below (hereinafter sometimes referred to as “acid stable monomer (a4-5)”) can also be used.

Among such acid-stable monomers (a4-5), (meth) acrylic acid 5- (3,3,3-trifluoro-2-hydroxy-2- [2-] having a monocyclic or polycyclic alicyclic 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 and 4,4-bis (trifluoromethyl) -3-oxatricyclo [4.2.1.0 ^2,5 ] nonyl (meth) acrylate are preferred. .

  When the resin (A) has an acid-stable structural unit derived from the acid-stable monomer (a4-5), the total content is 1 to 1 with respect to all the structural units (100 mol%) of the resin (A). The range of 20 mol% is preferable, the range of 2-15 mol% is more preferable, and the range of 3-10 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。］ <Acid stable monomer (a4-6)>
As the acid stable monomer (a4), an acid stable monomer having a group represented by the following formula (3) can also be used. Hereinafter, the acid-stable monomer having a group represented by the formula (3) is sometimes referred to as “acid-stable monomer (a4-6)”.

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

Examples of the fluorinated alkyl group for R ¹⁰ include 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) ester Tyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoro Pentyl 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 Groups and perfluorohexyl groups.

The fluorinated alkyl group of 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.

ここに示した酸安定モノマー（ａ４−６）の具体例において、酸安定モノマー（ａ４−４）の具体例と同様に、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）の具体例として含む。 As an acid stable monomer (a4-6), what is represented by the following is mentioned, for example.

In the specific example of the acid stable monomer (a4-6) shown here, as in the specific example of the acid stable monomer (a4-4), the partial structure M ′ is replaced with the partial structure A ′. It is included as a specific example of (a4-6).

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

  When the resin (A) has an acid stable structural unit derived from the acid stable monomer (a4-6), the content ratio is 5 to 90 with respect to the total structural unit (100 mol%) of the resin (A). The range of mol% is preferable, the range of 10-80 mol% is more preferable, and the range of 20-70 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−を構成するメチレン基は、酸素原子、カルボニル基又はスルホニル基に置き換わっていてもよく、−（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。］ <Acid stable monomer (a4-7)>
Examples of the acid stable monomer (a4) include acid stable monomers 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 ) _m10 —SO ₂ —O— * or — (CH ₂ ) _m10 —CO—O— *, and methylene constituting — (CH ₂ ) _m10 — 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. ]

The aromatic hydrocarbon group having 6 to 12 carbon atoms in R ¹¹ includes the same examples as the aryl groups in R ^{b1 to} R ^b3 of formula (2) except that the upper limit of the carbon number is different. 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. The aryl group substituted by an alkyl group having 1 to 4 carbon atoms is the same as those exemplified as R ^{b1 to} R ^b3 .

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 aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
Examples of the aliphatic hydrocarbon group, typically an alkyl group, specific examples thereof are the same as those exemplified as R ^a34 and R ^a35 of formula (a1-4). The alicyclic hydrocarbon group is the same as that exemplified for R ^{a1 to} R ^a3 in the formula (1) except that the upper limit of the carbon number is different.
In addition, when R < ¹² > is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, these aliphatic hydrocarbon groups or alicyclic hydrocarbon groups may contain a 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、
Ｒ^１３は、水素原子又はメチル基を表す。
Ｒ^１１、Ｒ^１２及びＡ^３は、上記と同じ意味を表す。］ As the acid stable monomer (a4) containing a group represented by the formula (4), for example, an acid stable monomer represented by the formula (a4-7) (hereinafter sometimes referred to as “acid stable monomer (a4-7)”) Said).

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

ここに示した酸安定モノマー（ａ４−７）の具体例において、酸安定モノマー（ａ４−４）の例示と同様に、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）の具体例として含む。 Examples of the acid stable monomer (a4-7) include the following.

In the specific examples of the acid-stable monomer (a4-7) shown here, as in the case of the acid-stable monomer (a4-4), the partial structure M ′ is replaced with the partial structure A ′. It is included as a specific example of a4-7).

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

［式（ａ４−８）中、
環Ｗ^３は、炭素数３〜３６の脂肪族環を表す。
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^３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のハロゲン化アルキル基を表す。
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のハロゲン化アルキル基を表す。 <Acid stable monomer (a4-8)>
As the acid stable monomer (a4), a monomer represented by the following formula (a4-8) (hereinafter sometimes referred to as “acid stable monomer (a4-8)”) may also be used.

[In the formula (a4-8),
Ring W ³ represents an aliphatic ring having ^{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 ³ , 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 halogenated alkyl 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 halogenated alkyl group having 1 to 6 carbon atoms.

で示される部分構造は、式（ＫＡ−１）〜式（ＫＡ−２２）で示した脂環式炭化水素に含まれる１個の水素原子がＡ^４との結合手に、脂環式炭化水素の環を構成する１つの炭素原子に結合している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^３である脂肪族環としては、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好ましい。 Ring W ³ is a monocyclic or polycyclic aliphatic ring having 3 to 36 carbon atoms, and the carbon number thereof is preferably in the range of 5 to 18, and more preferably in the range of 6 to 12. More specifically, in the description of the alicyclic hydrocarbon group, the aliphatic ring shown in the form of the alicyclic hydrocarbon represented by the formula (KA-1) to the formula (KA-22) may be mentioned. it can. That is, in formula (a6-1)

In the partial structure represented by the formula (KA-1) to the formula (KA-22), one hydrogen atom contained in the alicyclic hydrocarbon represented by the formula (KA-22) is bonded to A ⁴ to form an alicyclic hydrocarbon. And those in which two hydrogen atoms bonded to one carbon atom constituting the ring are replaced with bonds to —O—CO—R ¹⁵ and —O—CO—R ¹⁶ .
As the aliphatic ring which is ring W ³ , a cyclohexane ring, an adamantane ring, a norbornane ring and a norbornene ring are preferable.

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のアルカンジイル基を表し、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）及び式（Ｘ^ｘ−Ｃ）で表される基の総炭素数は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.
Here, a representative example of an aliphatic hydrocarbon group in which an alkanediyl group and an alicyclic hydrocarbon group are combined is shown. Examples of the aliphatic hydrocarbon group include groups represented by the following formula (X ^x -A), formula (X ^x -B), and formula (X ^x -C).

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

As described above, in the aliphatic hydrocarbon group of A ⁴ , the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. Representative examples of such groups include those exemplified for group (a-1) of formula (a). However, in the specific example of the group (a-1), one of * 1 and * 2 is read as a bond with the ring W ³ and the other is read as a bond with an oxygen atom.

A ⁴ is preferably a single bond or a group represented by * — (CH ₂ ) _s1 —CO—O— (* represents a bond to —O—, and s1 represents an integer of 1 to 6). , A single bond or a group represented by * —CH ₂ —CO—O— (* represents a bond to —O—) is more preferable.

R ¹⁴ is preferably a hydrogen atom or a methyl group.

The alkyl group of R ¹⁴ , R ¹⁵ and R ¹⁶ (hereinafter referred to as “R ^{14 to} R ¹⁶ ”) has a carbon number in the range of 1 to 6, and specific examples thereof are those already exemplified. including. As the halogenated alkyl group, an alkyl group having a fluorine atom is particularly preferable. Among the halogenated alkyl groups of R ¹⁵ and R ¹⁶ , preferred are trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group and the like, among which trifluoromethyl group, perfluoroethyl group and A perfluoropropyl group may be mentioned.

これらの中でも、

で表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 the acid stable monomers shown below. R ^{14 to} R ¹⁶ and A ⁴ represent the same meaning as described above.

Among these,

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

ここに示した酸安定モノマー（ａ４−８）において、酸安定モノマー（ａ４−４）の例示と同様に、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（ａ４−８）の具体例として含む。 Specific examples of the acid stable monomer (a4-8) are as follows.

In the acid stable monomer (a4-8) shown here, as in the case of the acid stable monomer (a4-4), the partial structure M ′ is replaced with the partial structure A ′. ) As a specific example.

［式（ａ４−８−ａ）及び式（ａ４−８−ｂ）中、Ａ^４、Ｒ^１４、Ｒ^１５及びＲ^１６は、上記と同じ意味を表し、

で表される部分構造は、上述の環Ｗ^３を構成するメチレン基の１つがカルボニル基に置き換わったものである。］ A preferable acid stable monomer (a4-8) can be produced, for example, as follows. That is, the acid stable monomer (a4-8) is produced by reacting the compound represented by the formula (a4-8-a) with the compound represented by the formula (a4-8-b). Typical 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.

[In formula (a4-8-a) and formula (a4-8-b), A ⁴ , R ¹⁴ , R ¹⁵ and R ¹⁶ represent the same meaning as described above,

Is a structure in which one of the methylene groups constituting the ring W ³ is replaced with a carbonyl group. ]

  When the resin (A) has an acid stable structural unit derived from the acid stable monomer (a4-8), the content ratio is 5 to 90 with respect to the total structural unit (100 mol%) of the resin (A). The range of mol% is preferable, the range of 10-80 mol% is more preferable, and the range of 20-70 mol% is more preferable.

<Resin (A) and production method thereof>
The resin (A) includes a compound (a ′) that derives the structural unit (a) and a monomer (a1) that induces the structural unit (a1) [preferably, the structural unit (a1-1) or the structural unit (a1− 2) -derived monomer (a1)] is more preferably copolymerized with an acid-stable monomer that induces acid-stable structural units, and more preferably, compound (a ′), structural unit (a1-) 1) and / or copolymerized monomer (a1) for deriving structural unit (a1-2), acid stable structural unit (a2) and / or acid stable monomer for deriving acid stable structural unit (a3) It is.
The resin (A) preferably has at least one of the structural unit (a1-1) having an adamantyl group and the structural unit (a1-2) having a cyclohexyl group as the structural unit (a1). It is more preferable to have a structural unit (a1-1) having an adamantyl group. 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 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 at least one kind. The resin (A) may be polymerized (copolymerized) by subjecting the above-described monomer to a known polymerization method (for example, radical polymerization method).

The content ratio of the structural unit (a1) to the total structural unit (100 mol%) of the resin (A) has already been described for each of the structural unit (a1-1) and the structural unit (a1-2). The total, that is, the total content of the structural unit (a1) is preferably in the range of 10 to 80 mol%, more preferably 20 to 60 mol, based on the total structural units (100 mol%) of the resin (A). % Range.
Moreover, when it has a structural unit (especially structural unit (a1-1)) which has an adamantyl group, this structural unit shall be 15 mol% or more with respect to the sum total (100 mol%) of a structural unit (a1). It is preferable. 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.

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

<This resist composition>
The resist composition exhibits an effect that a resist pattern having an excellent shape can be produced by containing the resin (A) having the structural unit (a) and the acid generator (B1) described later. The resist composition contains, in addition to the resin (A), constituents such as an acid generator and a solvent and, if necessary, an additive such as a basic compound called a quencher in this technical field. There is. In the following description, the solvent obtained by removing the solvent from the resist composition may be referred to as “solid content” of the resist composition. The content (content mass ratio) of the solid content relative to the total mass of the resist composition can be measured by a known analysis means such as liquid chromatography and gas chromatography.

式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１〜１７の飽和炭化水素基を表し、該飽和炭化水素きにあるメチレンきは、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又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該脂肪族炭化水素基にあるメチレン基は、酸素原子、スルホニル基又はカルボニル基で置き換わっていてもよく、該脂環基にあるメチレン基は、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。 <Acid generator>
The acid generator contained in the resist composition is preferably an acid generator represented by the following formula (B1). In the following description, the acid generator represented by the formula (B1) is sometimes referred to as “acid generator (B1)”, and among the acid generator (B1), Z ⁺ ( Those having a negative charge obtained by removing the organic cation) are referred to as “sulfonate anions”.

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 saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent; The methylene group in the group hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group, and the methylene group in the alicyclic group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group.
Z ⁺ represents an organic cation.

Perfluoroalkyl groups for Q ¹ and Q ² are, for example, perfluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and perfluorohexyl. Group and the like.
As the acid generator (B1) used in the resist composition, Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom acid generator (B1), and both Q ¹ and Q ² are The acid generator (B1) which is a fluorine atom is more preferable. The present resist composition containing an acid generator (B1) in which both Q ¹ and Q ² are fluorine atoms can produce a resist pattern having an excellent shape with a better focus margin.

Specific examples of the aliphatic hydrocarbon group represented by L ^b1 include the removal of two hydrogen atoms from the alkanediyl group already exemplified and the alicyclic hydrocarbons of the above formulas (KA-1) to (KA-22). Group.

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^b3及びＬ^b4の合計炭素数の上限は１３である。
Ｌ^b5は、炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b6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。
本レジスト組成物に用いるものとしては、これらの中でも、式（ｂ１−１）で表される２価の基をＬ^b1として有する酸発生剤（Ｂ１）が好ましく、Ｌ^b2が単結合又はメチレン基である式（ｂ１−１）で表される２価の基をＬ^b1として有する酸発生剤（Ｂ１）がより好ましい。 Examples of the methylene group constituting the aliphatic hydrocarbon group in L ^b1 replaced with an oxygen atom or a carbonyl group include the following formulas (b1-1), (b1-2), and (b1- 3), formula (b1-4), formula (b1-5), and formula (b1-6) [hereinafter expressed as “formula (b1-1) to formula (b1-6)”. ] The group shown by either of these is mentioned. L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4), more preferably a group represented by formula (b1-1) or a formula (b1-2). It is the group shown. Incidentally, the formula (b1-1) ~ formula (b1-6) has its left and right are described in accordance with the formula (B1), the left bond ^{is, C (Q 1) (Q} 2) coupled with and The right hand is connected to Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6). In addition, * represents a bond, one is bonded to Y, and the other is bonded to a carbon atom of CQ ¹ Q ² (carbon atom bonded to Q ¹ and Q ² ).

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 C1-C13 divalent aliphatic hydrocarbon group, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 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.
Among these, the acid generator (B1) having a divalent group represented by the formula (b1-1) as L ^b1 is preferable, and L ^b2 is a single bond or a methylene group. in a acid generator having a divalent group represented by L ^b1 in the formula (b1-1) (B1) it is more preferred.

Here, the specific example of the bivalent group represented by Formula (b1-1)-Formula (b1-6) is given. Note that * represents a bond, and the definition of * on the left and right is as described above.
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.

The aliphatic hydrocarbon group for L ^b1 may have a substituent. Examples of the substituent 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, an acyl group having 2 to 4 carbon atoms, and a glycidyloxy group. Can be mentioned. Specific examples of the aromatic hydrocarbon group, the aralkyl group, and the acyl group are as described above.

Y in Formula (B1) represents a C 1-18 aliphatic hydrocarbon group which may have a substituent. As the aliphatic hydrocarbon group, an alkyl group and an alicyclic hydrocarbon group are preferable, and an alkyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms are more preferable.
When the aliphatic hydrocarbon group for Y has a substituent, examples of the substituent include a halogen atom (excluding a fluorine atom), a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, and an alkyl group having 6 to 18 carbon atoms. An aromatic hydrocarbon group, 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 represents a hydrocarbon group having 1 to 16 carbon atoms, j2 represents an integer of 0 to 4, and the like. The aromatic hydrocarbon group and aralkyl group referred to here may further have, for example, an alkyl group, a halogen atom or a hydroxy group.
The methylene group constituting the aliphatic hydrocarbon group for Y may be replaced with a group selected from the group consisting of an oxygen atom, a sulfonyl group and a carbonyl group. Examples of the group in which the methylene group constituting the alicyclic hydrocarbon group is replaced by an oxygen atom, a sulfonyl group or a carbonyl group include, for example, a cyclic ether group (one or two of the methylene groups contained in the alicyclic hydrocarbon group are A group in which an oxygen atom is substituted), a cyclic ketone group (a group in which one or two methylene groups contained in an alicyclic hydrocarbon group are substituted with a carbonyl group), a sultone ring group (already described in the formula (a4-4)) As described above, of the methylene groups contained in the alicyclic hydrocarbon group, two adjacent methylene groups are each substituted with an oxygen atom and a sulfonyl group and a lactone ring group (included in the alicyclic hydrocarbon group). A group in which two adjacent methylene groups in the methylene group are replaced with an oxygen atom and a carbonyl group, respectively).

Preferred groups of the alicyclic hydrocarbon group of Y include groups represented by the following formula (Y1), formula (Y2), formula (Y3), formula (Y4) and formula (Y5), respectively. Of these, groups represented by formula (Y1), formula (Y2), formula (Y3) and formula (Y5) are more preferred, and alicyclic carbonization represented by formula (Y1) and formula (Y2), respectively. A hydrogen group is more preferable. In addition, the hydrogen atom contained in these alicyclic hydrocarbon groups may be substituted for the substituent.

Examples of the alicyclic hydrocarbon group formed by bonding an alkyl group to the carbon atom of the atoms constituting the ring include the following.

Examples of the alicyclic hydrocarbon group having a hydroxy group include the following.

Examples of the alicyclic hydrocarbon group having an aromatic hydrocarbon group include the following.

Examples of the alicyclic hydrocarbon group having a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 include the following.

  Y is preferably an adamantyl group optionally having a hydroxy group or the like as a substituent, and suitable Y includes an adamantyl group or a hydroxyadamantyl group.

Specifically, the sulfonate anion is represented by formula (b1-1-1), formula (b1-1-2), formula (b1-1-3), formula (b1-1-4), formula (b1- 1-5), formula (b1-1-6), formula (b1-1-7), formula (b1-1-8) and formula (b1-1-9) [formula (b1-1-1) to And sulfonate anions represented by formula (b1-1-1-9)], respectively. In the sulfonic acid anion represented by each of the formula (b1-1-1) to the formula (b1-1-1-9), L ^b1 is preferably a group represented by the formula (b1-1). R ^b2 and R ^b3 are each independently the same as those exemplified as the substituent that the aliphatic hydrocarbon group of Y may have, and an aliphatic hydrocarbon group having 1 to 4 carbon atoms and A hydroxy group is preferred, and a methyl group and a hydroxy group are more preferred.

Examples of the sulfonate anion in which Y is a chain aliphatic hydrocarbon group or an unsubstituted alicyclic hydrocarbon group, and L ^b1 is a group represented by the formula (b1-1) include the following. It is done.

A sulfonate anion in which Y is an unsubstituted alicyclic hydrocarbon group or an alicyclic hydrocarbon group having an aliphatic hydrocarbon group as a substituent, and L ^b1 is a group represented by the formula (b1-1) For example, the following may be mentioned.

A sulfonate anion in which Y is an alicyclic hydrocarbon group having a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 , and L ^b1 is a group represented by formula (b1-1) For example, the following may be mentioned.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having a hydroxy group and L ^b1 is a group represented by the formula (b1-1) include the following.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having an aromatic hydrocarbon group or an aralkyl group, and L ^b1 is a group represented by the formula (b1-1) include the following. It is done.

Examples of the sulfonate anion in which Y is the cyclic ether group and L ^b1 is a group represented by the formula (b1-1) include the following.

Examples of the sulfonate anion in which Y is the lactone ring group and L ^b1 is a group represented by the formula (b1-1) include the following.

Examples of the sulfonate anion in which Y is the cyclic ketone group and L ^b1 is a group represented by the formula (b1-1) include the following.

Examples of the sulfonate anion in which Y is the sultone ring group and L ^b1 is a group represented by the formula (b1-1) include the following.

Examples of the sulfonate anion in which Y is an aliphatic hydrocarbon group or an unsubstituted alicyclic hydrocarbon group, and L ^b1 is a group represented by the formula (b1-2) include the following. .

Y is a alicyclic hydrocarbon group having a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 , and L ^b1 is a group represented by the formula (b1-2). Examples of the anion include the following.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having a hydroxy group and L ^b1 is a group represented by the formula (b1-2) include the following.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having an aromatic hydrocarbon group and L ^b1 is a group represented by the formula (b1-2) include the following.

Examples of the sulfonate anion in which Y is the cyclic ether group and L ^b1 is a group represented by the formula (b1-2) include the following.

Examples of the sulfonate anion in which Y is the lactone ring group and L ^b1 is a group represented by the formula (b1-2) include the following.

Examples of the sulfonate anion in which Y is the cyclic ketone group and L ^b1 is a group represented by the formula (b1-2) include the following.

Examples of the sulfonate anion in which Y is the sultone ring group and L ^b1 is a group represented by the formula (b1-2) include the following.

Examples of the sulfonate anion in which Y is an aliphatic hydrocarbon group and L ^b1 is a divalent group represented by the formula (b1-3) include the following.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having an alkoxy group, and L ^b1 is a group represented by the formula (b1-3) include the following.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having a hydroxy group and L ^b1 is a divalent group represented by the formula (b1-3) include the following.

Examples of the sulfonate anion in which Y is the cyclic ketone group and L ^b1 is a group represented by the formula (b1-3) include the following.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group and L ^b1 is a group represented by the formula (b1-4) include the following.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having an alkoxy group and L ^b1 is a group represented by the formula (b1-4) include the following.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having a hydroxy group and L ^b1 is a group represented by the formula (b1-4) include the following.

Examples of the sulfonate anion in which Y is the cyclic ketone group and L ^b1 is a divalent group represented by the formula (b1-4) include the following.

Among the sulfonate anions exemplified above, those in which L ^b1 is a group represented by the formula (b1-1) are preferable. More preferred sulfonate anions are shown below.

Examples of the organic cation (Z ⁺ ) in the acid generator (B1) include organic onium cations such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, an organic sulfonium cation is more preferable, and further preferably, the following formula (b2-1), formula (b2-2), formula (b2-3), and formula ( b2-4) [Cation (b2-1) to Formula (b2-4)] [Cathion (b2-1)], [Cation (b2 -2) "," cation (b2-3) "and" cation (b2-4) ". ].

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

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

The alkylcarbonyloxy group for R ^b12 is a group in which the acyl group already exemplified and an oxygen atom are bonded.

^Of the chain aliphatic hydrocarbon groups ^{represented by} R ^{b9 to} R ^b12, a preferred group is an alkyl group, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a sec-butyl group. Group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group.
Among the alicyclic hydrocarbon groups represented by R ^{b9 to} R ^b11 , preferred groups are, for example, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyladamantan-2-yl group, 1 -(Adamantan-1-yl) alkane-1-yl group and isobornyl group.
^Among the aromatic hydrocarbon groups ^represented by R ^b12 , preferred groups are, for example, phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl. Group, biphenylyl group, naphthyl group and the like.
^Examples of the ^combination of the aromatic hydrocarbon group of R ^b12 and the chain aliphatic hydrocarbon group include an aralkyl group, and specifically include a benzyl group.
Examples of the ring formed by combining the combination of R ^b9 and R ^b10 include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Etc.
Examples of the ring formed by combining the combination of R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

式（ｂ２−１−１）中、
Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、炭素数１〜１８の脂肪族炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
該脂肪族炭化水素基としては、炭素数は１〜１２の脂肪族炭化水素基が好ましく、炭素数１〜１２のアルキル基及び炭素数４〜１８の脂環式炭化水素基がより好ましい。該脂肪族炭化水素基は、置換基として、ハロゲン原子、ヒドロキシ基、炭素数１〜１２のアルコキシ基、炭素数６〜１８の芳香族炭化水素基、炭素数２〜４のアシル基又はグリシジルオキシ基を有していてもよい。
ｖ２、ｗ２及びｘ２は、それぞれ独立に０〜５の整数（好ましくは０又は１）を表す。
ｖ２が２以上のとき、複数のＲ^b19は互いに同一でも異なっていてもよく、ｗ２が２以上のとき、複数のＲ^b20は互いに同一でも異なっていてもよく、ｘ２が２以上のとき、複数のＲ^b21は互いに同一でも異なっていてもよい。
なかでも、Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、好ましくは、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、炭素数１〜１２のアルキル基、又は炭素数１〜１２のアルコキシ基であることが好ましい。 Among the exemplified organic cations, the cation (b2-1) is preferable, and an organic cation represented by the following formula (b2-1-1) [hereinafter, referred to as “cation (b2-1-1)” may be used. ], More preferably a triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0) or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = X2 = 1, and R ^b19 , R ^b20 and R ^b21 are all methyl groups).

In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
As this aliphatic hydrocarbon group, a C1-C12 aliphatic hydrocarbon group is preferable, and a C1-C12 alkyl group and a C4-C18 alicyclic hydrocarbon group are more preferable. The aliphatic hydrocarbon group includes, as a substituent, a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or glycidyloxy. It may have a group.
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 may be the same as or different from each other. When w2 is 2 or more, the plurality of R ^b20 may be the same or different from each other. R ^b21 may be the same as or different from each other.
Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. It is preferably a group.

Examples of the cation (b2-1-1) include the following.

このような有機カチオンを有する酸発生剤（Ｂ１）を含有する本レジスト組成物は、より優れた形状のレジストパターンを製造することができる。

This resist composition containing the acid generator (B1) having such an organic cation can produce a resist pattern having a more excellent shape.

The cation (b2-1-1) which is already a suitable organic cation and specific examples thereof have been shown. Specific examples of the cation (b2-2), cation (b2-3) and cation (b2-4) are also shown. Let me show you.
Examples of the cation (b2-2) include the following.

Examples of the cation (b2-3) include the following.

Examples of the cation (b2-4) include the following.

  The acid generator (B1) is a combination of the above-described sulfonic acid anion and the above-mentioned organic cation, and these can be arbitrarily combined. Any of the formulas (b1-1-1) to (b1-1-9) Any one of the acid generator (B1), which is a combination of the sulfonate anion represented by the formula (b2-1-1), and the formula (b1-1-3) to the formula (b1-1-5) The acid generator (B1) which is a combination of the sulfonic acid anion represented by the above and the cation (b2-3) is preferred. The present resist composition containing such an acid generator (B1) can produce a resist pattern having a more excellent shape.

More preferred acid generator (B1) is specifically shown. Such an acid generator (B1) has the following formula (B1-1), formula (B1-2), formula (B1-3), formula (B1-4), formula (B1-5), formula (B) B1-6), formula (B1-7), formula (B1-8), formula (B1-9), formula (B1-10), formula (B1-11), formula (B1-12), formula (B1) -13), formula (B1-14), formula (B1-15), formula (B1-16) and salt represented by formula (B1-17). The acid generator (B1) is preferably a salt containing a triphenylsulfonium cation or a salt containing a tolylsulfonium cation, and is represented by the formula (B1-1), formula (B1-2), formula (B1-3), formula (B1). −6), salts represented by formula (B1-11), formula (B1-12), formula (B1-13) and (B1-14), respectively, are more preferable. In addition, as described above, an alicyclic hydrocarbon group which Y may have a substituent is preferable, and in this respect, the formula (B1-1), the formula (B1-2), the formula (B1 -3), the formula (B1-6), the formula (B1-11) and the formula (B1-12) are more preferable.

  The acid generator contained in the resist composition may contain an acid generator different from the acid generator (B1). In this case, the content ratio of the acid generator (B1) in the total amount of the acid generator is preferably 70% by mass or more, and more preferably 90% by mass or more. However, the acid generator in the resist composition is more preferably substantially only the acid generator (B1).

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition preferably contains a basic compound (C). The “basic compound” as used herein means a compound having a property of capturing an acid, particularly a compound having a property of capturing an acid generated from an acid generator.

  The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium hydroxides. The amine may be an aliphatic amine or an aromatic amine. As the aliphatic amine, any of primary amine, secondary amine and tertiary amine can be used. The aromatic amine may be either an aromatic ring such as aniline with an amino group bonded thereto or a heteroaromatic amine such as pyridine. Preferable basic compounds (C) include aromatic amines represented by the following formula (C2), particularly anilines represented by the following formula (C2-1).

式（Ｃ２）及び式（Ｃ２−１）中、
Ａｒ^c1は、芳香族炭化水素基を表す。
Ｒ^c5及びＲ^c6は、それぞれ独立に、水素原子、脂肪族炭化水素基（好ましくは、炭素数１〜６程度の鎖式脂肪族炭化水素基及び炭素数５〜１０程度の脂環式炭化水素基である。）又は芳香族炭化水素基（好ましくは、炭素数６〜１０程度の芳香族炭化水素基である。）を表す。但し、該脂肪族炭化水素基、該脂環式炭化水素基及び該芳香族炭化水素基に含まれる水素原子は、ヒドロキシ基、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、該アミノ基はさらに、炭素数１〜４のアルキル基を有していてもよい。
Ｒ^c7は、鎖式脂肪族炭化水素基（好ましくは、炭素数１〜６程度のアルキル基である。）、炭素数１〜６程度のアルコキシ基、脂環式炭化水素基（好ましくは、炭素数５〜１０程度の脂環式炭化水素基であり、より好ましくは、炭素数５〜１０程度のシクロアルキル基である。）又は芳香族炭化水素基（好ましくは、炭素数６〜１０程度の芳香族炭化水素基である。）を表す。但し、該脂肪族炭化水素基、該アルコキシ基、該脂環式炭化水素基及び該芳香族炭化水素基に含まれる水素原子も、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、該アミノ基はさらに、炭素数１〜４のアルキル基を有していてもよい。
ｍ３は０〜３の整数を表す。ｍ３が２以上のとき、複数のＲ^c7は、互いに同一でも異なってもよい。

In formula (C2) and formula (C2-1),
Ar ^c1 represents an aromatic hydrocarbon group.
R ^c5 and R ^c6 are each independently a hydrogen atom, an aliphatic hydrocarbon group (preferably a chain aliphatic hydrocarbon group having about 1 to 6 carbon atoms and an alicyclic hydrocarbon having about 5 to 10 carbon atoms. Or an aromatic hydrocarbon group (preferably an aromatic hydrocarbon group having about 6 to 10 carbon atoms). However, the hydrogen atom contained in the aliphatic hydrocarbon group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group is substituted with a hydroxy group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. The amino group may further have an alkyl group having 1 to 4 carbon atoms.
R ^c7 is a chain aliphatic hydrocarbon group (preferably an alkyl group having about 1 to 6 carbon atoms), an alkoxy group having about 1 to 6 carbon atoms, or an alicyclic hydrocarbon group (preferably carbon An alicyclic hydrocarbon group having about 5 to 10 carbon atoms, more preferably a cycloalkyl group having about 5 to 10 carbon atoms) or an aromatic hydrocarbon group (preferably having about 6 to 10 carbon atoms). Represents an aromatic hydrocarbon group. However, the hydrogen atom contained in the aliphatic hydrocarbon group, the alkoxy group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group is also a hydroxy group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. It may be substituted, and the amino group may further have an alkyl group having 1 to 4 carbon atoms.
m3 represents an integer of 0 to 3. When m3 is 2 or more, the plurality of R ^c7 may be the same as or different from each other.

式（Ｃ３）〜式（Ｃ１１）中、
Ｒ^c8は、上記Ｒ^c7で説明したいずれかの基を表す。
Ｒ^c20、Ｒ^c21、Ｒ^c23、Ｒ^c24、Ｒ^c25、Ｒ^c26、Ｒ^c27及びＲ^c28は、上記Ｒ^c7で説明したいずれかの基を表す。
Ｒ^c9、Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13、Ｒ^c14、Ｒ^c16、Ｒ^c19及びＲ^c22は、上記のＲ^c5及びＲ^c6で説明したいずれかの基を表す。
ｏ３、ｐ３、ｑ３、ｒ３、ｓ３、ｔ３及びｕ３は、それぞれ独立に０〜３の整数を表す。ｏ３が２以上であるとき、複数のＲ^c20は互いに同一でも異なっていてもよく、ｐ３が２以上であるとき、複数のＲ^c21は互いに同一でも異なっていてもよく、ｑ３が２以上であるとき、複数のＲ^c24は互いに同一でも異なっていてもよく、ｒ３が２以上であるとき、複数のＲ^c25は互いに同一でも異なっていてもよく、ｓ３が２以上であるとき、複数のＲ^c26は互いに同一でも異なっていてもよく、ｔ３が２以上であるとき、複数のＲ^c27は互いに同一でも異なっていてもよく、ｕ３が２以上であるとき、複数のＲ^c28は互いに同一でも異なっていてもよい。
Ｒ^c15は、脂肪族炭化水素基（好ましくは、炭素数１〜６程度の脂肪族炭化水素基である。）、脂環式炭化水素基（好ましくは、炭素数３〜６程度の脂環式炭化水素基である。）又はアルカノイル基（好ましくは、炭素数２〜６程度のアルカノイル基である。）を表す。
ｎ３は０〜８の整数を表す。ｎ３が２以上のとき、複数のＲ^c15は、それぞれ独立である。
Ｌ^c1及びＬ^c2は、それぞれ独立に、２価の脂肪族炭化水素基（好ましくは、炭素数１〜６程度の脂肪族炭化水素基であり、より好ましくは、炭素数１〜６程度のアルキレン基である。）、カルボニル基、−Ｃ（＝ＮＨ）−、−Ｃ（＝ＮＲ^c3）−（但し、Ｒ^c3は、炭素数１〜４のアルキル基を表す。）、硫黄原子、ジスルフィド結合（−Ｓ−Ｓ−）又はこれらの組合せを表す。 Examples of the aromatic amine represented by the formula (C2) include 1-naphthylamine and 2-naphthylamine.
Examples of the anilines represented by the formula (C2-1) include aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline and diphenylamine. Is mentioned.
Further, in the following formula (C3), formula (C4), formula (C5), formula (C6), formula (C7), formula (C8), formula (C9), formula (C10) and formula (C11), respectively. A compound represented (hereinafter, the compound referred to here is expressed as “compound (C3)” to “compound (C11)” depending on the formula number) can also be used.

In formula (C3) to formula (C11),
R ^c8 represents any of the groups described for R ^c7 above.
R ^c20 , R ^c21 , R ^c23 , R ^c24 , R ^c25 , R ^c26 , R ^c27 and R ^c28 represent any of the groups described for R ^c7 above.
R ^c9 , R ^c10 , R ^c11 , R ^c12 , R ^c13 , R ^c14 , R ^c16 , R ^c19 and R ^c22 represent any of the groups described above for R ^c5 and R ^c6 .
o3, p3, q3, r3, s3, t3 and u3 each independently represents an integer of 0 to 3. When o3 is 2 or more, the plurality of R ^c20 may be the same or different from each other. When p3 is 2 or more, the plurality of R ^c21 may be the same or different from each other, and q3 is 2 or more. when a plurality of R ^c24 may be the same or different, when r3 is 2 or more, plural R ^c25 may be the same or different, when s3 is 2 or more, plural R ^{c 26} when it may be the same or different, is t3 is 2 or more, plural R ^c27 may be the same or different, when u3 is 2 or more, the plurality of R ^{c 28} are identical or different from each other May be.
R ^c15 is an aliphatic hydrocarbon group (preferably an aliphatic hydrocarbon group having about 1 to 6 carbon atoms), an alicyclic hydrocarbon group (preferably an alicyclic group having about 3 to 6 carbon atoms). A hydrocarbon group) or an alkanoyl group (preferably an alkanoyl group having about 2 to 6 carbon atoms).
n3 represents an integer of 0 to 8. When n3 is 2 or more, the plurality of R ^c15 are each independent.
L ^c1 and L ^c2 are each independently a divalent aliphatic hydrocarbon group (preferably an aliphatic hydrocarbon group having about 1 to 6 carbon atoms, more preferably an alkylene having about 1 to 6 carbon atoms. A carbonyl group, -C (= NH)-, -C (= NR ^c3 )-(wherein R ^c3 represents an alkyl group having 1 to 4 carbon atoms), a sulfur atom, a disulfide bond. (-SS-) or a combination thereof is represented.

Examples of the compound (C4) include piperazine.
Examples of the compound (C5) include morpholine.
Examples of the compound (C6) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound (C7) include 2,2′-methylenebisaniline.
Examples of the compound (C8) include imidazole and 4-methylimidazole.
Examples of the compound (C9) include pyridine and 4-methylpyridine.
Examples of the compound (C10) 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 Examples include '-dipyridyl disulfide, 2,2'-dipyridylamine, and 2,2'-dipiconylamine.
Examples of the compound (C11) include bipyridine.

  Examples of the basic compound (C3) include hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine , Tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyl Dioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyl Hexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexa Use methylenediamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, etc. Can do.

  Examples of ammonium hydroxide include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, and 3- (trifluoromethyl). ) Phenyltrimethylammonium hydroxide and choline.

  As mentioned above, specific examples of the basic compound (C) have been shown. As the basic compound (C) used in the resist composition, diisopropylaniline is preferable, and 2,6-diisopropylaniline is particularly preferable.

<Solvent (hereinafter sometimes referred to as “solvent (D)”)>
The solvent (D) contained in the resist composition is a substrate in the production of a resist pattern, which will be described later, according to the type and amount of the resin (A) and the type and amount of the acid generator (B). An optimum one can be appropriately selected from the viewpoint that the coating property when the resist composition is applied to the top is improved. As described above, in the production of a resist pattern, the resist composition preferably contains a solvent (D) from the viewpoint that a resist film can be easily formed on a substrate by coating the resist composition.

  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 may contain, if necessary, a resin (A), an acid generator [preferably an acid generator (B1)], a solvent (D), and a basic compound (C) used as necessary. You may contain the structural component. This component may be referred to as “component (F)”. Such component (F) is not particularly limited, and includes additives known in the art, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes.

<This resist composition and its preparation method>
This resist composition is obtained by mixing the resin (A), the acid generator (B) and the solvent (D), or
It can be prepared by mixing the resin (A), the acid generator (B), the basic compound (C), and the solvent (D). Furthermore, a component (F) may be mixed as needed. In such mixing, the mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature range from the range of 10-40 degreeC according to the kind etc. of resin (A) to be used, the solubility with respect to the solvent (D) of resin (A). What is necessary is just to select mixing time according to mixing temperature, and 0.5 to 24 hours are preferable. The mixing means is not particularly limited, and stirring and mixing can be used.
The content of each component in the present resist composition can be adjusted by the amount of each component used in preparing the present resist composition.
Thus, after mixing each component with preferable content, it is preferable to filter using a filter with a pore diameter of about 0.01 to 0.2 μm.

The content ratio of the resin (A) 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.
In the present specification, the “solid content of the resist composition” means the total of the constituents of the resist composition excluding the solvent (D) described later. For example, in the present resist composition in which the content ratio of the solvent (D) is 90% by mass, the solid content in the present resist composition corresponds to 10% by mass. The solid content of the resist composition and the content of each component relative thereto can be measured by known analytical means such as liquid chromatography or gas chromatography, for example.

  The content ratio of the acid generator, particularly the acid generator (B1) is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and preferably 30 parts by mass with respect to 100 parts by mass of the resin (A). Part or less, more preferably 25 parts by weight or less.

  When the basic compound (C) is used in the resist composition, the content ratio is preferably about 0.01 to 1% by mass with respect to the total mass of the solid content of the resist composition.

  The content ratio of the solvent (D) can be appropriately adjusted according to the type of the resin (A) as described above, but is preferably 90% by mass or more, more preferably 92% by mass with respect to the total mass of the resist composition. It is above, More preferably, it is 94 mass% or more, 99.9 mass% or less is preferable, More preferably, it is 99 mass% or less. When the content ratio of the solvent (D) is within the above range, for example, in a resist pattern manufacturing method described later, a composition layer having a thickness of about 30 to 300 nm tends to be easily formed.

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

  As described above, after mixing the resin (A), the acid generator and the solvent (D), and the basic compound (C) or the component (F) used as necessary in a preferable content ratio, the pore size is 0. The resist composition can be prepared by filtration using a filter of about 0.01 to 0.2 μm.

<Method for producing resist pattern>
Then, the manufacturing method of the resist pattern using this resist composition is demonstrated.
The method for producing a resist pattern of the present invention comprises:
(1) a step of applying the resist composition on a substrate;
(2) drying the composition after coating to form a composition layer on the substrate;
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) It includes a step of developing the heated composition layer using a developing device. Hereinafter, each of the steps shown here is referred to as “step (1)” to “step (5)”.

  Application of the resist composition on the substrate in the step (1) can be performed by a coating apparatus widely used for applying a resist material for semiconductor microfabrication, such as a spin coater. Thus, a coating film made of a resist composition is formed on the substrate. The film thickness of the coating film can be adjusted by variously adjusting the conditions (coating conditions) of the coating apparatus, and by applying an appropriate preliminary experiment, the coating film can be applied to have a desired film thickness. You can choose the conditions. Various substrates to be subjected to microfabrication can be selected as the substrate before applying the resist composition. The substrate may be washed or an antireflection film may be formed before applying the resist composition. For example, a commercially available composition for an organic antireflection film can be used for forming the antireflection film.

In the step (2), the solvent [solvent (D)] is removed from the resist composition coated on the substrate, that is, the coated film. Such solvent removal is performed by evaporating the solvent from the coating film by, for example, heating means using a heating device such as a hot plate (so-called pre-baking), decompressing means using a decompressing device, or a combination of these means. Is done. Conditions for the heating means and the decompression means can be selected according to the type of the solvent (D) contained in the resist composition. For example, in the case of a heating means using a hot plate, the surface temperature of the hot plate is set to 50 to 200. It is preferable that the temperature be in the range of about ° C. In the decompression means, after the substrate on which the coating film is formed is sealed in an appropriate decompressor, the internal pressure of the decompressor may be set to about 1 to 1.0 × 10 ⁵ Pa. Thus, the composition layer is formed on the substrate by removing the solvent from the coating film.

Step (3) is a step of exposing the composition layer, and preferably the composition layer is exposed using an exposure machine. At this time, exposure is performed through a mask (photomask) on which a desired pattern pattern to be finely processed is formed. As an exposure light source of the exposure machine, an ultraviolet light source such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm), or a solid-state laser light source (YAG In addition, various lasers such as a laser beam from a laser beam from a semiconductor laser or the like to emit a harmonic laser beam in the far ultraviolet region or the vacuum ultraviolet region can be used. The exposure machine may be an immersion exposure machine. Further, the exposure machine may irradiate an electron beam or extreme ultraviolet light (EUV).
As described above, by exposing through a mask, an exposed portion (exposed portion) and an unexposed portion (unexposed portion) are generated in the composition layer. In the composition layer of the exposed portion, the acid generator (B1) contained in the composition layer receives exposure energy to generate an acid, and further acts with the generated acid to generate an acid labile group in the resin (A). Produces a hydrophilic group by the deprotection reaction, and as a result, the resin (A) in the composition layer of the exposed portion becomes soluble in an alkaline aqueous solution. On the other hand, since the exposure energy is not received in the unexposed area, the resin (A) remains insoluble or hardly soluble in the alkaline aqueous solution. Thus, the composition layer in the exposed portion and the composition layer in the unexposed portion are significantly different in solubility in the alkaline aqueous solution.

  In the step (4), a heat treatment (so-called post-exposure baking) for further promoting the progress of the deprotecting group reaction that may occur in the exposed portion is performed. Such heat treatment is preferably the heating means using the hot plate shown in the step (2). In addition, when performing hot plate heating in a process (4), about 50-200 degreeC is preferable and the surface temperature of this hot plate has more preferable about 70-150 degreeC. The deprotection reaction is promoted by heat treatment.

Step (5) is a step of developing the heated composition layer, and preferably a step of developing the heated composition layer using a developing device. In the step of developing, when the heated composition layer is brought into contact with an alkaline aqueous solution, the exposed composition layer is dissolved and removed in the alkaline aqueous solution, and the unexposed composition layer remains on the substrate. A resist pattern is manufactured on the substrate.
As the alkaline aqueous solution, those known in this technical field called “alkaline developer” can be used. Examples of the alkaline aqueous solution include an aqueous solution of tetramethylammonium hydroxide and an aqueous solution of (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).

  After development, the manufactured resist pattern is preferably rinsed with ultrapure water or the like, and water remaining on the substrate and the resist pattern is preferably removed.

<Application>
The resist composition includes a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) irradiation, or a resist composition for an EUV exposure machine, and a liquid immersion It is suitable as a resist composition for exposure.
Can be used for construction.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography (GPC). 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)

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

式（Ｄ−ａ）で表される化合物２５．３１部及びテトラヒドロフラン２００．００部を反応器に仕込み、室温で攪拌した。式（Ｄ−ａ）で表される化合物が完溶したことを目視で確認した後、ピリジン１４．２７部を加え、４０℃まで昇温した。さらに、クロロアセチルクロリド２５．４７部及びテトラヒドロフラン５０部の混合溶液を１時間かけて滴下した。滴下後、４０℃で８時間攪拌し、次いで５℃まで冷却した。５℃に冷却したイオン交換水１００．００部を添加、攪拌し、分液により水層を回収した。回収された水層に酢酸エチル６５．００部を添加し、分液して有機層を回収した。回収された有機層に、５℃の１０％炭酸カリウム水溶液６５．００部を添加して洗浄し、分液して有機層を回収した後、回収された有機層にさらに、イオン交換水６５．００部を添加して水洗し、分液を行って有機層を回収した。この水洗操作を３回繰り返して行った。回収された有機層を濃縮した後、残渣をカラム分取（カラム条件 固定相 メルク社製シリカゲル６０−２００メッシュ；展開溶媒：酢酸エチル）することにより、式（Ｄ−ｂ）で表される化合物２２．２４部を得た。 Example 1 [Synthesis of Compound Represented by Formula (D) (Compound (a ′))]

25.31 parts of the compound represented by the formula (D-a) and 200.00 parts of tetrahydrofuran were charged into a reactor and stirred at room temperature. After visually confirming that the compound represented by the formula (Da) was completely dissolved, 14.27 parts of pyridine was added, and the temperature was raised to 40 ° C. Further, a mixed solution of 25.47 parts of chloroacetyl chloride and 50 parts of tetrahydrofuran was added dropwise over 1 hour. After dropping, the mixture was stirred at 40 ° C. for 8 hours and then cooled to 5 ° C. 100.00 parts of ion-exchanged water cooled to 5 ° C. was added and stirred, and the aqueous layer was recovered by liquid separation. 65.00 parts of ethyl acetate was added to the recovered aqueous layer, and the organic layer was recovered by liquid separation. The recovered organic layer was washed by adding 65.00 parts of a 10% aqueous potassium carbonate solution at 5 ° C. and separated to recover the organic layer, and then the ion-exchanged water 65. 00 parts were added and washed with water, followed by liquid separation to recover the organic layer. This washing operation was repeated 3 times. After concentrating the collected organic layer, the residue is subjected to column fractionation (column conditions, stationary phase, silica gel 60-200 mesh manufactured by Merck & Co .; developing solvent: ethyl acetate), whereby the compound represented by the formula (Db) 22.24 parts were obtained.

式（Ｄ−ｃ）で表される化合物７．５０部及びＮ，Ｎ’−ジメチルホルムアミド３７．５０部を反応器に仕込み、２３℃で３０分間攪拌した。得られた混合物に、炭酸カリウム３．２０部及びヨウ化カリウム０．９６部を加え、５０℃で１時間攪拌した。得られた混合物に、式（Ｄ−ｂ）で表される化合物８．５０部をＮ，Ｎ’−ジメチルホルムアミド１６．８７部に溶解した溶液を１時間かけて滴下し、５０℃で５時間攪拌した。得られた混合物を、２３℃まで冷却し、酢酸エチル１５０部及びイオン交換水７５部を加えて攪拌し、分液した。回収された有機層をイオン交換水７５部で水層が中性になるまで水洗を繰り返した。回収された有機層を濃縮した後、残渣をカラム分取（カラム条件 固定相 メルク社製シリカゲル６０−２００メッシュ；展開溶媒：酢酸エチル）することにより、式（Ｄ−ｄ）で表される化合物１０．２９部を得た。

7.50 parts of the compound represented by the formula (Dc) and 37.50 parts of N, N′-dimethylformamide were charged into the reactor and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 3.20 parts of potassium carbonate and 0.96 parts of potassium iodide were added, and the mixture was stirred at 50 ° C. for 1 hour. A solution prepared by dissolving 8.50 parts of the compound represented by the formula (Db) in 16.87 parts of N, N′-dimethylformamide was added dropwise to the obtained mixture over 1 hour, and the mixture was stirred at 50 ° C. for 5 hours. Stir. The obtained mixture was cooled to 23 ° C., 150 parts of ethyl acetate and 75 parts of ion-exchanged water were added, and the mixture was stirred and separated. The collected organic layer was repeatedly washed with 75 parts of ion-exchanged water until the aqueous layer became neutral. After the collected organic layer is concentrated, the residue is subjected to column fractionation (column conditions, stationary phase, silica gel 60-200 mesh manufactured by Merck & Co .; developing solvent: ethyl acetate), whereby the compound represented by the formula (D-d) 10.29 parts were obtained.

7.54 parts of the compound represented by the formula (D-d) and 37.50 parts of acetonitrile were charged into a reactor, stirred at 23 ° C. for 30 minutes, and then cooled to 5 ° C. To the obtained mixture, 0.36 part of sodium borohydride and 5.32 parts of ion-exchanged water were added and stirred at 5 ° C. for 3 hours. To the obtained mixture, 25 parts of ion-exchanged water and 50 parts of ethyl acetate were added, stirred and separated. The collected organic layer was repeatedly washed with 25 parts of ion-exchanged water until the aqueous layer became neutral. After concentrating the collected organic layer, the residue is subjected to column fractionation (column conditions, stationary phase, silica gel 60-200 mesh manufactured by Merck; developing solvent: ethyl acetate), whereby the compound represented by the formula (De) 6.33 parts were obtained.

  4.69 parts of a compound represented by the formula (De), 1.68 parts of N-methylpyrrolidine and 25.00 parts of tetrahydrofuran were charged into a reactor, and 1.55 parts of methacryloyl chloride was added at 23 ° C. with stirring to 40 parts. After dropwise addition over a period of time, the mixture was stirred at 23 ° C. for 4 hours. Thereafter, 25 parts of ion-exchanged water and 50 parts of ethyl acetate were added and washed, followed by liquid separation to recover the organic layer. 25 parts of ion-exchanged water was added to the collected organic layer for washing, and liquid separation was performed to collect the organic layer. This washing operation was repeated three times. To the collected organic layer, 2.00 parts of magnesium sulfate was added, stirred and filtered. The collected filtrate layer is concentrated, and the residue is fractionated in a column (column conditions, stationary phase, silica gel 60-200 mesh manufactured by Merck; developing solvent: ethyl acetate), and 1.22 parts of the compound represented by the formula (D) Got.

  MASS: 472.3

式（Ｋ−ｃ）で表される化合物７．５８部及びＮ，Ｎ’−ジメチルホルムアミド３７．９０部を反応器に仕込み、２３℃で３０分間攪拌した。得られた混合物に、炭酸カリウム３．２０部及びヨウ化カリウム０．９６部を加え、５０℃で１時間攪拌した。得られた混合物に、式（Ｄ−ｂ）で表される化合物８．５０部をＮ，Ｎ’−ジメチルホルムアミド１６．８７部に溶解した溶液を１時間かけて滴下し、５０℃で５時間攪拌した。得られた混合物を、２３℃まで冷却し、酢酸エチル１５０部及びイオン交換水７５部を加えて攪拌し、分液した。回収された有機層をイオン交換水７５部で水層が中性になるまで水洗を繰り返した。回収された有機層を濃縮した後、残渣をカラム分取（カラム条件 固定相 メルク社製シリカゲル６０−２００メッシュ；展開溶媒：酢酸エチル）することにより、式（Ｋ−ｄ）で表される化合物８．８４部を得た。

Example 2 [Synthesis of Compound Represented by Formula (K) (Compound (a ′))]

7.58 parts of the compound represented by the formula (Kc) and 37.90 parts of N, N′-dimethylformamide were charged into a reactor and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 3.20 parts of potassium carbonate and 0.96 parts of potassium iodide were added, and the mixture was stirred at 50 ° C. for 1 hour. A solution prepared by dissolving 8.50 parts of the compound represented by the formula (Db) in 16.87 parts of N, N′-dimethylformamide was added dropwise to the obtained mixture over 1 hour, and the mixture was stirred at 50 ° C. for 5 hours. Stir. The obtained mixture was cooled to 23 ° C., 150 parts of ethyl acetate and 75 parts of ion-exchanged water were added, and the mixture was stirred and separated. The collected organic layer was repeatedly washed with 75 parts of ion-exchanged water until the aqueous layer became neutral. After the collected organic layer is concentrated, the residue is subjected to column fractionation (column conditions, stationary phase, silica gel 60-200 mesh manufactured by Merck & Co .; developing solvent: ethyl acetate), whereby the compound represented by the formula (Kd) 8.84 parts were obtained.

  4.69 parts of a compound represented by the formula (Kd), 1.68 parts of N-methylpyrrolidine and 25.00 parts of tetrahydrofuran were charged into a reactor, and 1.55 parts of methacryloyl chloride were added at 23 ° C. with stirring to 40 parts. After dropwise addition over a period of time, the mixture was stirred at 23 ° C. for 4 hours. Thereafter, 25 parts of ion-exchanged water and 50 parts of ethyl acetate were added and washed, followed by liquid separation to recover the organic layer. 25 parts of ion-exchanged water was added to the collected organic layer for washing, and liquid separation was performed to collect the organic layer. This washing operation was repeated three times. To the collected organic layer, 2.00 parts of magnesium sulfate was added, stirred and filtered. After the collected filtrate layer is concentrated, the residue is subjected to column fractionation (column conditions, stationary phase, silica gel 60-200 mesh manufactured by Merck & Co .; developing solvent: ethyl acetate), and 2.34 parts of the mixture represented by the formula (K) (Note that the compound (a ′) represented by the formula (K) is a mixture of the above two compounds).

  MASS: 472.3

以下、これらのモノマーを「モノマー（Ａ）」〜「モノマー（Ｋ）」という。 Examples 3 to 10 and Synthesis Example 1 (Synthesis of resin)
The compounds (monomers) used in the resin synthesis are shown below.

Hereinafter, these monomers are referred to as “monomer (A)” to “monomer (K)”.

Example 3 [Synthesis of Resin A1]
As the monomer, monomer (E), monomer (F), monomer (C), monomer (G) and monomer (D) are used, and their molar ratio (monomer (E): monomer (F): monomer (C): monomer (G): Monomer (D)) was mixed so as to be 35: 5: 25: 30: 5, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of a methanol / water mixed solvent (the methanol / water weight ratio of this mixed solvent was 4/1. The same applies hereinafter) to precipitate the resin, and the resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 0 × 10 ³ resin A1 (copolymer) was obtained with a yield of 65%. This resin A1 has the following structural units.

Example 4 [Synthesis of Resin A2]
As the monomer, the monomer (E), the monomer (H), the monomer (F), the monomer (C), the monomer (G) and the monomer (D) are used, and the molar ratio (monomer (E): monomer (H): monomer (F): Monomer (C): Monomer (G): Monomer (D)) were mixed so that the ratio was 32: 6: 4: 20: 30: 8, and 1.5 mass times the total amount of dioxane was added. In addition, a solution was obtained. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 0 × 10 ³ resin A2 (copolymer) was obtained with a yield of 60%. This resin A2 has the following structural units.

Example 5 [Synthesis of Resin A3]
As the monomer, monomer (E), monomer (H), monomer (C), monomer (G) and monomer (D) are used, and their molar ratio (monomer (E): monomer (H): monomer (C): monomer (G): Monomer (D)) was mixed so as to be 32: 6: 20: 30: 12, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 2 × 10 ³ resin A3 (copolymer) was obtained with a yield of 58%. This resin A3 has the following structural units.

Example 6 [Synthesis of Resin A4]
Monomer (A), monomer (C), and monomer (D) are used as the monomers and mixed so that the molar ratio (monomer (A): monomer (C): monomer (D)) is 50:25:25. Then, 1.5 mass times dioxane of the total monomer amount was added to make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 68 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice, and the weight average molecular weight was 8. 8 × 10 ³ resin A4 (copolymer) was obtained with a yield of 52%. This resin A4 has the following structural units.

Synthesis Example 1 [Synthesis of Resin A5]
Monomer (A), monomer (B), and monomer (C) are used as the monomers and mixed so that the molar ratio (monomer (A): monomer (B): monomer (C)) is 50:25:25. Then, 1.5 mass times dioxane of the total monomer amount was added to make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 70 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice, and the weight average molecular weight was 8. 8 × 10 ³ resin A5 (copolymer) was obtained with a yield of 68%. This resin A5 has the following structural units.

Example 7: [Synthesis of Resin A6]
As the monomer, the monomer (E), the monomer (H), the monomer (F), the monomer (C), the monomer (G) and the monomer (D) are used, and the molar ratio (monomer (E): monomer (H): monomer (F): Monomer (C): Monomer (G): Monomer (D)) were mixed so as to be 30: 14: 4: 20: 28: 4, and 1.5 mass times dioxane of the total monomer amount. To make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 70 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, and this resin was filtered twice. The weight average molecular weight was 7 8 × 10 ³ resin A6 (copolymer) was obtained with a yield of 82%. This resin A6 has the following structural units.

Example 8: [Synthesis of Resin A7]
As the monomer, the monomer (E), the monomer (J), the monomer (F), the monomer (C), the monomer (G) and the monomer (D) are used, and the molar ratio (monomer (E): monomer (J): monomer (F): Monomer (C): Monomer (G): Monomer (D)) were mixed so as to be 30: 14: 4: 20: 28: 4, and 1.5 mass times dioxane of the total monomer amount. To make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 70 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, and this resin was filtered twice. The weight average molecular weight was 7 0.7 × 10 ³ resin A7 (copolymer) was obtained with a yield of 81%. This resin A7 has the following structural units.

Example 9: [Synthesis of Resin A8]
As the monomer, monomer (I), monomer (J), monomer (F), monomer (C), monomer (G) and monomer (D) are used, and their molar ratio (monomer (I): monomer (J): monomer (F): Monomer (C): Monomer (G): Monomer (D)) were mixed so as to be 30: 14: 4: 20: 28: 4, and 1.5 mass times dioxane of the total monomer amount. To make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 70 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, and this resin was filtered twice. The weight average molecular weight was 7 2 × 10 ³ resin A8 (copolymer) was obtained with a yield of 62%. This resin A8 has the following structural units.

Example 10: [Synthesis of Resin A9]
As the monomer, monomer (E), monomer (J), monomer (F), monomer (C), monomer (G) and monomer (K) are used, and their molar ratio (monomer (E): monomer (J): monomer (F): Monomer (C): Monomer (G): Monomer (K)) were mixed so as to be 30: 14: 4: 20: 28: 4, and dioxane of 1.5 mass times the total monomer amount. To make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 70 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, and this resin was filtered twice. The weight average molecular weight was 7 0.5 × 10 ³ resin A9 (copolymer) was obtained with a yield of 78%. This resin A9 has the following structural units.

Examples 11 to 18 and Comparative Example 1
<Preparation of resist composition>
Resins A1 to A5 obtained in Synthesis Example 1;
Acid generator B1 shown below;
Basic compound C1 shown below;
Each was dissolved in the solvent shown below in parts by mass shown in Table 1, and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a resist composition.

<Resin>
A1 to A9: Resin A1 to Resin A9
<Acid generator>
B1:

<Basic compound: Quencher>
C1: 2,6-diisopropylaniline <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 and its evaluation>
The resist compositions of Examples 2 to 5 and the resist composition of Comparative Example 1 were subjected to shape evaluation by immersion exposure as follows. Hereinafter, the resist composition and the resist composition of Comparative Example 1 may be collectively referred to as “resist composition”.

<Immersion exposure evaluation of resist composition>
The resist composition was subjected to immersion exposure and the shape was evaluated as follows.
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Co., Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 780 mm. An organic antireflection film was formed. Subsequently, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) was 85 nm.
After coating the resist composition, the obtained silicon wafer was pre-baked (PB) for 60 seconds at a temperature described in the “PB” column of Table 1 on a direct hot plate to form a composition layer. An ArF excimer laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light] was used for the wafer on which the composition layer (resist composition film) was thus formed. The line and space pattern was subjected to immersion exposure by changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, post exposure bake (PEB) is performed on the hot plate at a temperature described in the “PEB” column of Table 1 for 60 seconds, and further with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 60 seconds. Paddle development was performed to obtain a resist pattern (line and space pattern).

<Shape evaluation>
A 50 nm line and space pattern was observed with a scanning electron microscope. Almost all of the top shape of the line and space pattern has a good shape close to a rectangle “good” (denoted as “g”), and a part of the top shape of the line and space pattern has a round shape. It was evaluated at two levels, “bad” (indicated as “b”).
These results are shown in Table 2.

  From this resist composition, a resist pattern having an excellent shape could be formed. On the other hand, the shape of the resist pattern obtained from the resist composition of Comparative Example 1 was poor.

  Since the resist composition of the present invention can produce a resist pattern having an excellent shape, it is useful for fine processing of semiconductors.

Claims (11)

Resin which has a structural unit represented by Formula (a).

[In the formula (a),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent, a single bond, or formula (a-1).

(In the formula (a-1),
t represents an integer of 0-2.
A ¹⁰ represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ¹¹ represents an optionally substituted aliphatic hydrocarbon group having 1 to 5 carbon atoms, and when t is 2, two A ¹¹ may be the same as or different from each other.
A ¹² represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent or a single bond.
X ¹⁰ and X ¹¹ represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group, and when s is 2, the two X ¹⁰ are independent of each other.
However, the total number of carbon atoms of A ¹⁰ , A ¹¹ , X ¹⁰ and X ¹¹ is 6 or less.
* 1 bond to ring W ^1, * 2 represents a bond to an oxygen atom. )
Represents a group represented by
A ² represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms, and the methylene group constituting the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
Ring W ¹ and ring W ² each independently represent an aliphatic ring having 4 to 36 carbon atoms.
s represents 1 or 2. ] A ^{1 in the} formula (a) is a single bond or
* 1 —CH ₂ —CO—O— * 2
(* 1 and * 2 have the same meaning as above.)
The resin according to claim 1. A ^{2 in the} formula (a) is
_{* 3-O-CH 2 -CO} -O- * 4 or
_{* 3-CO-O-CH} 2 -CO-O- * 4
(* 3 and * 4 are one bond with ring W ¹ and the other with ring W ^2. )
The resin according to claim 1 or 2. In the formula (a)

The resin according to claim 1, wherein the partial structure represented by the formula is a structure represented by the formula (W ¹ -a) or the formula (W ¹ -b).

In the formula (a)

In the partial structure represented has the formula (W 2 ^-a) in the structure any description of the resin of claims 1 to 4 is represented.

Furthermore, resin in any one of Claims 1-5 which have at least 1 sort (s) chosen from the group which consists of a structural unit represented by Formula (a1-1), and a structural unit represented by Formula (a1-2).

[In the 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). To express.
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 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O— (k1 is as defined above).
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. ]   A resist composition comprising the resin according to claim 1 and an acid generator. The resist composition according to claim 7, wherein the acid generator is represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent saturated 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 constituting 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 8, wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. (1) The process of apply | coating the resist composition in any one of Claim 7-9 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure,
(5) a step of developing the composition layer after heating;
A method for producing a resist pattern including: A compound represented by formula (a ′).

[In the formula (a ′),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent, a single bond, or formula (a-1).

(In the formula (a-1),
t represents an integer of 0-2.
A ¹⁰ represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ¹¹ represents an optionally substituted aliphatic hydrocarbon group having 1 to 5 carbon atoms, and when t is 2, two A ¹¹ may be the same as or different from each other.
A ¹² represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent or a single bond.
X ¹⁰ and X ¹¹ represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group, and when s is 2, the two X ¹⁰ are independent of each other.
However, the total number of carbon atoms of A ¹⁰ , A ¹¹ , X ¹⁰ and X ¹¹ is 6 or less.
* 1 bond to ring W ^1, * 2 represents a bond to an oxygen atom. )
Represents a group represented by
A ² represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms, and the methylene group constituting the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
Ring W ¹ and ring W ² each independently represent an aliphatic ring having 4 to 36 carbon atoms.
s represents 1 or 2. ]