JP2012226313A - Resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition from which a resist pattern having excellent CD (critical dimension) uniformity (CDU) can be produced.SOLUTION: The resist composition includes the following (A), (B) and (X): (A) a resin which is insoluble or hardly soluble with an alkali aqueous solution and can be dissolved in an alkali aqueous solution by the action of an acid; (B) an acid generator comprising a sulfonium salt or an iodonium salt; and (X) a salt expressed by formula (I). In formula (I), Land Leach independently represent an alkane diyl group or the like; Rand Reach independently represent an alkyl group; Rrepresents SOor the like; and W represents a group having a steroid structure.

Description

  The present invention relates to a resist composition and the like.

  In the production of a resist pattern using a resist composition, a coating film obtained by coating the resist composition on a substrate is irradiated with far-ultraviolet light, and an acid is applied to a portion (exposed portion) irradiated with far-ultraviolet light in the coating film. This is carried out by changing the solubility of the exposed portion and the unexposed portion (the portion of the coating film not irradiated with far ultraviolet light) in the developer by the reaction using this acid as a catalyst.

  Such a resist composition includes a compound that generates energy upon irradiation with far ultraviolet light (acid generator), and a resin that is insoluble or hardly soluble in an aqueous alkali solution and can be dissolved in an aqueous alkali solution by the action of an acid. And are contained. In order to prevent acid deactivation in the exposed area, the resist composition may further contain a basic compound called a quencher in the art. Patent Document 1 describes a resist composition containing diisopropylaniline as a resist composition containing such a basic compound.

JP 2007-161707 A

  There is a need for resist compositions that can produce resist patterns with even better CD uniformity (CDU) as the design dimensions of semiconductor processing become increasingly finer. In the above-described resist compositions known hitherto, the CD uniformity (CDU) of the obtained pattern may not always be sufficiently satisfied.

［式（Ｉ）中、
Ｌ^１及びＬ^２は、互いに独立に、炭素数１〜１２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、−ＮＲ^５−（Ｒ^５は、水素原子又は炭素数１〜６のアルキル基を表す。）又はカルボニル基で置き換わっていてもよく、該アルカンジイル基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
Ｒ^２及びＲ^３は、互いに独立に、炭素数１〜６のアルキル基を表す。
Ｒ^４は、ＳＯ_３ ⁻、ＣＯ_２ ⁻又はＯ⁻を表す。
Ｗは、式（Ｗ−Ｉ）

（式（Ｗ−Ｉ）中、
ｎは、０〜６の整数を表す。
Ｒ^１は、炭素数１〜１２の１価の脂肪族炭化水素基又は炭素数６〜１２の１価の芳香族炭化水素基を表し、該１価の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。
ｎが２以上の場合、複数存在するＲ^１の全部又は一部は同じであってもよい。
環を構成しているメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
点線は、当該点線を含む結合が、単結合であっても二重結合であってもよいことを表す。
ｍは、１〜５の整数を表す。
＊は、Ｌ^１との結合手である。）
で表される基である。］
〔２〕前記式（Ｉ）のＬ^１が、以下の式（Ｉ−１）で表される基である、前記〔１〕記載のレジスト組成物。

（式（Ｉ−１）中、
Ｒ^６及びＲ^７は、ヒドロキシ基を有していてもよいアルカンジイル基を表し、Ｒ^６及びＲ^７の合計炭素数は、２〜１０の範囲である。
２つの＊は結合手を表し、左側の＊はＷとの結合手であり、右側の＊は窒素原子との結合手である。）
〔３〕前記式（Ｉ）のＬ^１が、
＊−ＣＨ（ＣＨ_３）−ＣＨ_２−ＣＨ_２−ＣＯ−ＮＨ−（ＣＨ_２）_ｏ−＊
（２つの＊は結合手を表し、左側の＊はＷとの結合手であり、右側の＊は窒素原子との結合手である。ｏは１〜６の整数を表す。）
である、前記〔１〕記載のレジスト組成物。
〔４〕前記式（Ｉ）のＬ^２が、
＊−（ＣＨ_２）_ｌ−＊
（２つの＊は結合手を表し、ｌは１〜１２の整数を表す。この基を構成するメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよく、当該メチレン基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置き換わってもよい。）
である、前記〔１〕〜〔３〕のいずれか記載のレジスト組成物。
〔５〕前記（Ｂ）が、以下の式（Ｂ１）で表される塩からなる酸発生剤である、前記〔１〕〜〔４〕のいずれか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、炭素数１〜１７の２価の脂肪族飽和炭化水素基を表し、該２価の脂肪族飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８の１価の脂肪族炭化水素基を表し、該１価の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、有機スルホニウムカチオン又は有機ヨードニウムカチオンを表す。］
〔６〕前記式（Ｂ１）のＬ^b1が、以下の式（ｂ１−１）で表される基である、前記〔５〕記載のレジスト組成物。

［式（ｂ１−１）中、
Ｌ^b2は、単結合又は炭素数１〜１５の脂肪族飽和炭化水素基を表す。
２つの＊は結合手を表し、左側の＊は、Ｃ（Ｑ¹）（Ｑ²）の炭素原子との結合手、右側の＊は、Ｙとの結合手である。］
〔７〕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〔５〕又は〔６〕記載のレジスト組成物。
〔８〕（１）前記〔１〕〜〔７〕のいずれか記載のレジスト組成物を基板上に塗布する
工程；
（２）塗布後の組成物を乾燥させて組成物層を形成する工程；
（３）組成物層を露光する工程；
（４）露光後の組成物層を加熱する工程；及び
（５）加熱後の組成物層を現像する工程
を含むレジストパターンの製造方法。
〔９〕式（Ｉ）で表される塩のレジスト組成物用添加剤としての使用。

［式（Ｉ）中、
Ｌ^１及びＬ^２は、互いに独立に、炭素数１〜１２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、−ＮＲ^５−（Ｒ^５は、水素原子又は炭素数１〜６のアルキル基を表す。）又はカルボニル基で置き換わっていてもよく、該アルカンジイル基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
Ｒ^２及びＲ^３は、互いに独立に、炭素数１〜６のアルキル基を表す。
Ｒ^４は、ＳＯ_３ ⁻、ＣＯ_２ ⁻又はＯ⁻を表す。
Ｗは、式（Ｗ−Ｉ）

（式（Ｗ−Ｉ）中、
ｎは、０〜６の整数を表す。
Ｒ^１は、炭素数１〜１２の１価の脂肪族炭化水素基又は炭素数６〜１２の１価の芳香族炭化水素基を表し、該１価の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。
ｎが２以上の場合、複数存在するＲ^１の全部又は一部は同じであってもよい。
環を構成しているメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
点線は、当該点線を含む結合が、単結合であっても二重結合であってもよいことを表す。
ｍは、１〜５の整数を表す。
＊は、Ｌ^１との結合手である。）
で表される基である。］ In view of the above circumstances, the present inventors have intensively studied, and as a result, have reached the present invention. That is, the present invention includes the following inventions.
[1] A resist composition containing the following (A), (B) and (X).
(A) a resin that is insoluble or hardly soluble in an alkaline aqueous solution and can be dissolved in an alkaline aqueous solution by the action of an acid;
(B) an acid generator comprising a sulfonium salt or an iodonium salt,
(X) a salt represented by the formula (I)

[In the formula (I),
L ¹ and L ² each independently represent an alkanediyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkanediyl group is an oxygen atom, —NR ⁵ — (R ⁵ is a hydrogen atom or carbon Represents an alkyl group of 1 to 6) or a carbonyl group, and a hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a hydroxy group.
R ² and R ³ each independently represent an alkyl group having 1 to 6 carbon atoms.
R ⁴ represents SO ₃ ⁻ , CO ₂ ^— or O ⁻ .
W is the formula (W-I)

(In the formula (W-I),
n represents an integer of 0 to 6.
R ¹ represents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and a methylene group constituting the monovalent aliphatic hydrocarbon group. May be replaced by an oxygen atom or a carbonyl group.
When n is 2 or more, all or a part of the plurality of R ¹ may be the same.
The methylene group constituting the ring may be replaced with an oxygen atom or a carbonyl group.
The dotted line represents that the bond including the dotted line may be a single bond or a double bond.
m represents an integer of 1 to 5.
* Is a bond to ^{L 1.} )
It is group represented by these. ]
[2] The resist composition according to [1], wherein L ¹ in the formula (I) is a group represented by the following formula (I-1).

(In the formula (I-1),
R ⁶ and R ⁷ represent an alkanediyl group which may have a hydroxy group, and the total carbon number of R ⁶ and R ⁷ is in the range of 2 to 10.
Two * 's represent a bond, the left * is a bond with W, and the * on the right is a bond with a nitrogen atom. )
[3] L ^{1 in the} formula (I) is
* —CH (CH ₃ ) —CH ₂ —CH ₂ —CO—NH— (CH ₂ ) _o — *
(Two * 's represent a bond, the left * represents a bond with W, and the right * represents a bond with a nitrogen atom. O represents an integer of 1 to 6.)
The resist composition as described in [1] above.
[4] L ^{2 in the} formula (I) is
*-(CH ₂ ) _l- *
(Two * 's represent a bond, and l represents an integer of 1 to 12. The methylene group constituting this group may be replaced by an oxygen atom or a carbonyl group, and the hydrogen atom contained in the methylene group is , May be replaced by a fluorine atom or a hydroxy group.)
The resist composition according to any one of [1] to [3].
[5] The resist composition according to any one of [1] to [4], wherein (B) is an acid generator composed of a salt represented by the following 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 aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. .
Y represents a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and the methylene group constituting the monovalent aliphatic hydrocarbon group includes an oxygen atom, a sulfonyl group Alternatively, it may be replaced with a carbonyl group.
Z ⁺ represents an organic sulfonium cation or an organic iodonium cation. ]
[6] The resist composition according to [5], wherein L ^{b1 in the} formula (B1) is a group represented by the following formula (b1-1).

[In the formula (b1-1),
L ^b2 represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
Two * 's represent a bond, the left * is a bond with a carbon atom of C (Q ¹ ) (Q ² ), and the right * is a bond with Y. ]
[7] The resist composition according to [5] or [6], wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent.
[8] (1) The resist composition according to any one of [1] to [7] is applied on a substrate.
Process;
(2) The process of drying the composition after application | coating and forming a composition layer;
(3) a step of exposing the composition layer;
(4) A step of heating the composition layer after exposure; and (5) A method for producing a resist pattern, comprising a step of developing the composition layer after heating.
[9] Use of a salt represented by the formula (I) as an additive for a resist composition.

[In the formula (I),
L ¹ and L ² each independently represent an alkanediyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkanediyl group is an oxygen atom, —NR ⁵ — (R ⁵ is a hydrogen atom or carbon Represents an alkyl group of 1 to 6) or a carbonyl group, and a hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a hydroxy group.
R ² and R ³ each independently represent an alkyl group having 1 to 6 carbon atoms.
R ⁴ represents SO ₃ ⁻ , CO ₂ ^— or O ⁻ .
W is the formula (W-I)

(In the formula (W-I),
n represents an integer of 0 to 6.
R ¹ represents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and a methylene group constituting the monovalent aliphatic hydrocarbon group. May be replaced by an oxygen atom or a carbonyl group.
When n is 2 or more, all or a part of the plurality of R ¹ may be the same.
The methylene group constituting the ring may be replaced with an oxygen atom or a carbonyl group.
The dotted line represents that the bond including the dotted line may be a single bond or a double bond.
m represents an integer of 1 to 5.
* Is a bond to ^{L 1.} )
It is group represented by these. ]

  If the resist composition of the present invention is used, a resist pattern having excellent CD uniformity (CDU) can be produced.

The resist composition of the present invention (hereinafter sometimes referred to as “the present resist composition”)
(A) A resin that is insoluble or hardly soluble in an alkaline aqueous solution and can be dissolved in an alkaline aqueous solution by the action of an acid (hereinafter sometimes referred to as “resin (A)”);
(B) an acid generator comprising a sulfonium salt or an iodonium salt (hereinafter sometimes referred to as “acid generator (B)”);
(X) A salt represented by the above formula (I) (hereinafter sometimes referred to as “salt (X)”).
Each of these is characterized by containing. The resist composition may also contain a known basic compound (hereinafter sometimes referred to as “basic compound (C)”) that functions as the quencher. The resist composition preferably contains (D) a solvent (hereinafter, sometimes referred to as “solvent (D)”).
Hereinafter, with respect to the salt (X), a suitable one will be mainly described. Further, the resin (A), the acid generator (B), the basic compound (C), the solvent (D) and the like are also described as suitable, and a method for preparing the present resist composition containing these, and the present resist A method for producing a resist pattern using the composition will be described.

In the present specification, unless otherwise specified, the following examples of substituents are applied to any chemical structural formula having the same substituents while appropriately selecting the number of carbon atoms. Among the aliphatic hydrocarbon groups, those that can be linear or branched, such as an alkyl group, include any of them. When stereoisomers exist, all stereoisomers are included. In the following examples of substituents, the numerical value attached to “C” indicates the number of carbon atoms of each group.
Further, in the present specification, "(meth) acrylic monomer", "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " at least one monomer having the structure Means. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

  In the present specification, the “hydrocarbon group” includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group is further classified into a chain type and an alicyclic type.

Of the chain aliphatic hydrocarbon groups (chain hydrocarbon groups), the monovalent one is typically an alkyl group. Examples of the alkyl group include a methyl group (C ₁ ), an ethyl group (C ₂ ), Propyl group (C ₃ ), 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 ), etc. It may be linear or branched. Unless particularly limited, this chain hydrocarbon group may contain a carbon-carbon double bond in a part of the alkyl groups exemplified herein, but does not have such a carbon-carbon double bond, etc. Of these, a chain hydrocarbon group, particularly a saturated alkyl group, is preferred. The divalent chain hydrocarbon group corresponds to an alkanediyl group obtained by removing one hydrogen atom from the alkyl group shown here.

Monovalent alicyclic aliphatic hydrocarbon groups (hereinafter sometimes referred to as “alicyclic hydrocarbon groups”) typically remove one hydrogen atom from an alicyclic hydrocarbon. It is a group. The alicyclic hydrocarbon group may be an unsaturated alicyclic hydrocarbon group containing about one carbon-carbon unsaturated bond, or an alicyclic saturated hydrocarbon group containing no such carbon-carbon unsaturated bond. The alicyclic hydrocarbon group referred to in the present specification is preferably saturated. The alicyclic hydrocarbon group may be monocyclic or polycyclic. Here, an alicyclic hydrocarbon group will be illustrated by illustrating an alicyclic hydrocarbon before removing a hydrogen atom. The monocyclic alicyclic hydrocarbon is a group in which one hydrogen atom of a cycloalkane represented by the following formulas (KA-1) to (KA-7) is removed.

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個取り去った基が該当する。 The polycyclic alicyclic hydrocarbon is a group in which one hydrogen atom of a cycloalkane represented by the following formulas (KA-8) to (KA-22) is removed.

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

In the present specification, 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 ). . The divalent aromatic hydrocarbon group is typically an arylene group obtained by further removing one hydrogen atom from a monovalent aromatic hydrocarbon group.

  The aliphatic hydrocarbon group may have a substituent. Examples of such a substituent include a halogen atom, an alkoxy group, an acyl group, an aryl group, an aralkyl group, and an aryloxy group.

The halogen atom is a fluorine atom, a chlorine atom, a bromine atom and an iodine atom unless otherwise specified.
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 ), and these alkoxy groups may be linear or branched.
Specific examples of the acyl group are acetyl group (C ₂ ), propionyl group (C ₃ ), butyryl group (C ₄ ), valeryl group (C ₅ ), hexanoyl group (C ₆ ), heptanoyl group (C ₇ ), octanoyl In addition to those in which an alkyl group such as a group (C ₈ ), decanoyl group (C ₁₀ ) and dodecanoyl group (C ₁₂ ) and a carbonyl group are bonded, an aryl group and a carbonyl group such as a benzoyl group (C ₇ ) Are combined. Among these acyl groups, an alkyl group and a carbonyl group bonded to each other may be linear or branched.
Specific examples of the aryl group are the same as those exemplified as the aryl group of the above-mentioned aromatic hydrocarbon group, and specific examples of the aryloxy group are those in which the aryl group and an oxygen atom are bonded.
Specific examples of the aralkyl group include a benzyl group (C ₇ ), a phenethyl group (C ₈ ), a phenylpropyl group (C ₉ ), a naphthylmethyl group (C ₁₁ ), and a naphthylethyl group (C ₁₂ ).

  The aromatic hydrocarbon group may also have a substituent. Examples of such a substituent include a halogen atom, an alkoxy group, an acyl group, an alkyl group, and an aryloxy group. Among these, the alkyl group is the same as those exemplified as the chain aliphatic hydrocarbon group, and among the substituents optionally present in the aromatic hydrocarbon group, those other than the alkyl group are aliphatic hydrocarbon groups. The same thing as what was illustrated as a substituent of is included.

［式（Ｉ）中、
Ｌ^１及びＬ^２は、互いに独立に、炭素数１〜１２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、−ＮＲ^５−（Ｒ^５は、水素原子又は炭素数１〜６のアルキル基を表す。）又はカルボニル基で置き換わっていてもよく、該アルカンジイル基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
Ｒ^２及びＲ^３は、互いに独立に、炭素数１〜６のアルキル基を表す。
Ｒ^４は、ＳＯ_３ ⁻、ＣＯ_２ ⁻又はＯ⁻を表す。
Ｗは、式（Ｗ−Ｉ）

（式（Ｗ−Ｉ）中、
ｎは、０〜６の整数を表す。
Ｒ^１は、炭素数１〜１２の１価の脂肪族炭化水素基又は炭素数６〜１２の１価の芳香族炭化水素基を表し、該１価の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。
ｎが２以上の場合、複数存在するＲ^１の全部又は一部は同じであってもよい。
環を構成しているメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
点線は、当該点線を含む結合が、単結合であっても二重結合であってもよいことを表す。
ｍは、１〜５の整数を表す。
＊は、Ｌ^１との結合手である。）
で表される基である。］ <Salt (X)>
The salt (X) contained in the resist composition is represented by the formula (I) as described above.

[In the formula (I),
L ¹ and L ² each independently represent an alkanediyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkanediyl group is an oxygen atom, —NR ⁵ — (R ⁵ is a hydrogen atom or carbon Represents an alkyl group of 1 to 6) or a carbonyl group, and a hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a hydroxy group.
R ² and R ³ each independently represent an alkyl group having 1 to 6 carbon atoms.
R ⁴ represents SO ₃ ⁻ , CO ₂ ^— or O ⁻ .
W is the formula (W-I)

(In the formula (W-I),
n represents an integer of 0 to 6.
R ¹ represents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and a methylene group constituting the monovalent aliphatic hydrocarbon group. May be replaced by an oxygen atom or a carbonyl group.
When n is 2 or more, all or a part of the plurality of R ¹ may be the same.
The methylene group constituting the ring may be replaced with an oxygen atom or a carbonyl group.
The dotted line represents that the bond including the dotted line may be a single bond or a double bond.
m represents an integer of 1 to 5.
* Is a bond to ^{L 1.} )
It is group represented by these. ]

L ¹ and L ^{2 in} the formula (I) will be described. L ¹ and L ² each independently represent an alkanediyl group having 1 to 12 carbon atoms, the methylene group constituting the alkanediyl group is an oxygen atom, —NR ⁵ — (R ⁵ is as defined above). Or may be replaced by a carbonyl group. In addition, the hydrogen atom contained in the alkanediyl group may be replaced with a fluorine atom or a hydroxy group. As such, the hydrogen group contained in the alkanediyl group is preferably a hydroxy group.

（式（Ｉ−１）中、
Ｒ^６及びＲ^７は、ヒドロキシ基を有していてもよいアルカンジイル基を表し、Ｒ^６及びＲ^７の合計炭素数は、２〜１０の範囲である。
２つの＊は結合手を表し、左側の＊はＷとの結合手であり、右側の＊は窒素原子との結合手である。）
Ｒ^６及びＲ^７の合計炭素数は、２〜８の範囲であると好ましく、４〜６の範囲であるとさらに好ましい。 More preferably, L ¹ is a group in which a methylene group constituting an alkanediyl group is replaced with —NR ⁵ — (R ⁵ is as defined above), and more preferably, L ¹ is the following: It is group represented by the formula (I-1).

(In the formula (I-1),
R ⁶ and R ⁷ represent an alkanediyl group which may have a hydroxy group, and the total carbon number of R ⁶ and R ⁷ is in the range of 2 to 10.
Two * 's represent a bond, the left * is a bond with W, and the * on the right is a bond with a nitrogen atom. )
The total number of carbon atoms of R ⁶ and R ⁷ is preferably in the range of 2-8, and more preferably in the range of 4-6.

By using the obtained easily starting material, is in that it can easily produce the salt (X), L ¹ is
* —CH (CH ₃ ) —CH ₂ —CH ₂ —CO—NH— (CH ₂ ) _o — *
(Two * 's represent a bond, the left * represents a bond with W, and the right * represents a bond with a nitrogen atom. O represents an integer of 1 to 6.)
It is preferable that
* —CH (CH ₃ ) —CH ₂ —CH ₂ —CO—NH—CH ₂ —CH ₂ —CH ₂ — *
(Two * 's represent a bond, the left * is a bond with W, and the * on the right is a bond with a nitrogen atom.)
It is more preferable that

Similarly, considering the ease of production of the salt (X), L ² is
*-(CH ₂ ) _l- *
(Two * 's represent a bond, and l represents an integer of 1 to 12. The methylene group constituting this group may be replaced by an oxygen atom or a carbonyl group, and the hydrogen atom contained in the methylene group is , May be replaced by a fluorine atom or a hydroxy group.)
It is preferable that
_{* -CH 2 - *, * -} CH 2 -CH 2 -CH 2 - *, * - CH 2 -CH (OH) -CH 2 - *, * - CH 2 -CH 2 -CF 2 - * or * - more preferably _{*, * - - CH 2 -CH} 2 -CH 2 -O-CO-CF 2 CH 2 - *, * - CH 2 -CH 2 -CH 2 - * or _* -CH 2 -CH More preferably, it is (OH) —CH ₂ — *. Note that the two * 's in this specific example have the same meaning as described above.

R ² and R ³ each independently represent an alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, and more preferably R ² and R ³ are both methyl groups.

R ⁴ is an anionic group of SO ₃ ⁻ , CO ₂ ^— or O ⁻ . R ⁴ is preferably SO ₃ ^— or CO ₂ ^— , and more preferably SO ₃ ^— . This anionic group is electrically neutralized by a quaternary nitrogen atom (cationic group) present in the same molecule (in the salt (X)) to form a salt.

（式（Ｗ−Ｉ）中、
ｎは、０〜６の整数を表す。
Ｒ^１は、炭素数１〜１２の１価の脂肪族炭化水素基又は炭素数６〜１２の１価の芳香族炭化水素基を表し、該１価の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。
ｎが２以上の場合、複数存在するＲ^１の全部又は一部は同じであってもよい。
環を構成しているメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
点線は、当該点線を含む結合が、単結合であっても二重結合であってもよいことを表す。
ｍは、１〜５の整数を表す。
＊は、Ｌ^１との結合手である。） As described above, W is a group represented by the formula (WI) (hereinafter, sometimes referred to as “group (WI)”).

(In the formula (W-I),
n represents an integer of 0 to 6.
R ¹ represents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and a methylene group constituting the monovalent aliphatic hydrocarbon group. May be replaced by an oxygen atom or a carbonyl group.
When n is 2 or more, all or a part of the plurality of R ¹ may be the same.
The methylene group constituting the ring may be replaced with an oxygen atom or a carbonyl group.
The dotted line represents that the bond including the dotted line may be a single bond or a double bond.
m represents an integer of 1 to 5.
* Is a bond to ^{L 1.} )

In other words, the group (W-I) is included in a cyclopentahydrophenanthrene ring compound represented by the following formula (W-II), formula (W-III) or formula (W-IV) 1 The number of hydrogen atoms is replaced with a bond to L ^1, and m (1 to 5) hydrogen atoms are replaced with hydroxy groups. In addition, n (0 to 6) hydrogen atoms may be substituted with R ¹ . In addition, m representing the number of hydroxy groups is preferably in the range of 1 to 3.

The methylene group constituting the ring (cyclopentahydrophenanthrene ring compound) represented by formula (W-II), formula (W-III) and formula (W-IV) is an oxygen atom or a carbonyl group. It may be replaced. The ring optionally has a substituent R ¹ . Briefly describing R ¹ , the aliphatic hydrocarbon group having 1 to 12 carbon atoms includes a chain type and an alicyclic hydrocarbon group, and these specific examples have already been exemplified in this range. Including things. Further, the aliphatic hydrocarbon group of R ¹ may be a combination of a chain hydrocarbon group and an alicyclic hydrocarbon group in the range of 12 or less carbon atoms.
The aromatic hydrocarbon group having 6 to 12 carbon atoms of R ¹ includes those already exemplified in this range.
Among these, one hydrogen atom contained in the cyclopentahydrophenanthrene ring compound represented by the formula (W-II) is substituted with a bond to L ^1, and m hydrogen atoms are hydroxy groups. Has been replaced.

Specific examples of the salt (X) include those represented by the following formulas (X-1) to (X-22).

  Among the specific examples of the salt (X), those represented by any one of the formulas (X-1) to (X-12) and the formula (X-21) are preferable, and the formula (X-1) To those represented by any one of formula (X-8), formula (X-11) and formula (X-21) are more preferred, and formula (X-1) to formula (X-4), formula (X X-11) and a compound represented by formula (X-21) are more preferred, and a salt represented by formula (I-1), formula (X-11) or formula (X-21) (X Is even more preferred.

  Any of the salts (X) represented by the above formulas (X-1) to (X-22) can be easily obtained from the market, or any known method (for example, WO 2007/045386). Reference) can be synthesized. The salt (X) that can be easily obtained from the market is applied to, for example, biosurfactant. By adding this salt (X) to the resist composition, that is, as an additive for resist composition, The fact that a resist pattern having excellent CD uniformity can be produced is based on the inventor's original knowledge.

この原料化合物と、適当なジアミン（エチレンジアミン、プロピレン−１，３−ジアミン及び１−アミノメチル−２−アミノエタノールなど）とを縮合させ、該原料化合物に含まれるカルボキシ基をアミド結合に転換して、中間体を得る。この中間体に含まれる１級アミノ基を、例えば、エシュバイヤークラーク反応（反応剤：ホルマリン／還元剤（蟻酸など））などを用いることによりジメチル化したのち、２−ブロモエタンスルホン酸又はその塩、プロパンサルトンあるいはヒドロキシプロパンサルトンなどによりベタイン化すれば、Ｒ^４がＳＯ_３ ⁻である塩（Ｘ）が得られる。ここでいう、２−ブロモエタンスルホン酸などを例えば、クロロ酢酸又はその塩などに変更して、ベタイン化すれば、Ｒ^４がＣＯ_２ ⁻である塩（Ｘ）が得られる。 As described above, it is particularly preferable to use the salt (X) that is easily available from the market as it is or after being purified as necessary after being used in the resist composition, because the preparation of the resist composition becomes easier. Where L ¹ is
* —CH (CH ₃ ) —CH ₂ —CH ₂ —CO—NH— (CH ₂ ) _o — *
(Two * 's represent a bond, the left * represents a bond with W, and the right * represents a bond with a nitrogen atom. O represents an integer of 1 to 6.)
Taking the salt (X) as an example, the production method will be briefly described. First, raw material compounds as shown below are prepared.

This raw material compound is condensed with an appropriate diamine (ethylenediamine, propylene-1,3-diamine, 1-aminomethyl-2-aminoethanol, etc.), and the carboxy group contained in the raw material compound is converted into an amide bond. To obtain an intermediate. The primary amino group contained in this intermediate is dimethylated by using, for example, the Eschbayer-Clark reaction (reactant: formalin / reducing agent (formic acid, etc.)), and then 2-bromoethanesulfonic acid or a salt thereof , Propane sultone or hydroxypropane sultone can be used to obtain a salt (X) in which R ⁴ is SO ₃ ^— . When 2-bromoethanesulfonic acid or the like mentioned here is changed to, for example, chloroacetic acid or a salt thereof and betaineized, a salt (X) in which R ⁴ is CO ₂ ^— is obtained.

<Resin (A)>
As described above, the resin (A) contained in the resist composition is insoluble or hardly soluble in an alkaline aqueous solution, and can be dissolved in an alkaline aqueous solution by the action of an acid (hereinafter, sometimes referred to as “acid action characteristic”). ). By containing this resin (A), this resist composition can manufacture a resist pattern by the effect | action of the acid generate | occur | produced from the acid generator (B) mentioned later. Note that “can be dissolved 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 soluble in an alkaline aqueous solution after contact with an acid”. Means.

  The resin (A) having acid action characteristics has an acid labile group (hereinafter, sometimes referred to as “acid labile group”) in its molecule. Such a resin (A) is a monomer having an acid labile group (hereinafter, this monomer is sometimes referred to as “monomer (a1)”, and the structural unit derived from the monomer (a1) is referred to as “structural unit (a1)”. Can be produced by polymerization. In producing the resin (A) having acid action characteristics, the monomer (a1) may be used alone, or two or more kinds may be used in combination.

［式（１）中、
Ｒ^a1〜Ｒ^a3は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜２０の脂環式炭化水素基を表すか、Ｒ^a1及びＲ^a2は互いに結合して、これらが結合する炭素原子とともに炭素数３〜２０の環を形成する。＊は結合手を表す。］

［式（２）中、
Ｒ^a1’及びＲ^a2’は、それぞれ独立に、水素原子又は炭素数１〜１２の１価の炭化水素基を表し、Ｒ^a3’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a2’及びＲ^a3’は互いに結合して、これらが結合する炭素原子とともに炭素数３〜２０の環を形成する。該１価の炭化水素基及び該２価の炭化水素基を構成するメチレン基は、酸素原子又は硫黄原子に置き換わってもよい。＊は結合手を表す。］ <Acid labile group>
The “acid labile group” means a group that cleaves a leaving group upon contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). Examples of the acid labile group include a group represented by the formula (1) (acid labile group (1)) and a group represented by the formula (2) (acid labile group (2)). .

[In Formula (1),
R ^{a1 to} R ^a3 each independently represents an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^a1 and R ^a2 are bonded to each other, and these are bonded A ring having 3 to 20 carbon atoms is formed together with carbon atoms to be formed. * Represents a bond. ]

[In Formula (2),
R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^{a3 ′ a2 ′} and R ^{a3 ′} are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. The monovalent hydrocarbon group and the methylene group constituting the divalent hydrocarbon group may be replaced with an oxygen atom or a sulfur atom. * Represents a bond. ]

The alkyl group and alicyclic hydrocarbon group of R ^{a1 to} R ^a3 of the acid labile group (1) include those already exemplified in the range of 1 to 20 carbon atoms. However, the carbon number of the alicyclic hydrocarbon group is preferably in the range of 5-20.

The case where R ^a1 and R ^a2 are bonded to each other to form a ring is when the group represented by —C (R ^a1 ) (R ^a2 ) (R ^a3 ) is any of the following groups: is there. The number of carbon atoms in the ring formed by combining R ^a1 and R ^a2 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), groups in which R ^{a1 to} R ^a3 are alkyl groups, preferably a tert-butoxycarbonyl group), 2- An alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 combine to form an adamantyl ring, and R ^a3 is an alkyl group) and 1- (adamantane-1- Yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

Examples of the R ^{a1 ′} and R ^{a2 ′} hydrocarbon groups of the acid labile group (2) include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. Among these groups, the same groups are included in the range having 20 or less carbon atoms. However, at least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

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

  The monomer (a1) having an acid labile group [preferably an acid labile group (1) and / or an acid labile group (2)] preferably has an acid labile group and a carbon-carbon double bond. More preferably, it is a (meth) acrylic monomer having an acid labile group.

  Of the (meth) acrylic monomers having an acid labile group, the monomer (a1) having an alicyclic hydrocarbon group having 5 to 20 carbon atoms is preferred. Since the resin (A) obtained using such a monomer (a1) has a bulky structure such as an alicyclic hydrocarbon group, the resist composition containing the resin (A) The resolution tends to be better.

［式（ａ１−１）中、
Ｌ^a1は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−（ｋ１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。）で表される基を表す。
Ｒ^a4は、水素原子又はメチル基を表す。
Ｒ^a6は、炭素数１〜１０の脂肪族炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
式（ａ１−２）中、
Ｌ^a2は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−（ｋ１は前記と同義である。）で表される基を表す。
Ｒ^a5は、水素原子又はメチル基を表す。
Ｒ^a7は、炭素数１〜１０の脂肪族炭化水素基を表す。
ｎ１は０〜１０の整数を表す。
ｎ１’は０〜３の整数を表す。］ <Preferred structural unit (a1)>
The resin (A) having a suitable structural unit (a1) obtained by using the monomer (a1) having such an alicyclic hydrocarbon group will be further described in detail. Among the resins (A), a structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as “structural unit (a1-1)”) or a structural unit represented by the formula (a1-2) A resin having (hereinafter, referred to as “structural unit (a1-2)” in some cases) is preferable. Such a resin may have the structural unit (a1-1) as a single species, may have multiple types, or may have the structural unit (a1-2) as a single species, You may have multiple types and you may have combining the structural unit (a1-1) and the structural unit (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.
n1 ′ represents an integer of 0 to 3. ]

L ^a1 and L ^a2 are preferably an oxygen atom or a group represented by * —O— (CH ₂ ) _k1 —CO—O—, wherein k1 is an integer of 1 to 4, more preferably an oxygen atom. or * -O-CH ₂ -CO-O- and, still more preferably an oxygen atom.
R ^a4 and R ^a5 are preferably methyl groups.
Of the aliphatic hydrocarbon groups of R ^a6 and R ^a7 , preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and within the range of the upper limit of the carbon number, Includes the same as those already exemplified. The aliphatic hydrocarbon groups for R ^a6 and R ^a7 are each independently preferably an alkyl group having 8 or less carbon atoms or an alicyclic hydrocarbon group having 8 or less carbon atoms, more preferably an alkyl group having 6 or less carbon atoms. Or it is an alicyclic hydrocarbon group having 6 or less carbon atoms.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

Examples of the monomer (a1) capable of deriving the structural unit (a1-1) include those described in JP-A No. 2010-204646. Of the structural units (a1-1) derived from these, structural units represented by any of the following formulas (a1-1-1) to (a1-1-8) are preferred, and the formula (a1-1) -1) to a structural unit represented by any one of formulas (a1-1-3) and (a1-1-7) is more preferable.

  Examples of the monomer represented by the formula (a1-1) include monomers described in JP 2010-204646 A. Monomers represented by the following formulas (a1-1-1) to (a1-1-8) are preferred, and monomers represented by the following formulas (a1-1-1) to (a1-1-4) are more preferred. .

On the other hand, examples of the monomer (a1) capable of deriving the structural unit (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, 1 -Ethylcycloheptan-1-yl (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (meth) acrylate and the like.
As the structural unit (a1-2), those represented by any of the following formulas (a1-2-1) to (a1-2-6) are preferable. Among these, the structural unit represented by the formula (a1-2-3) or (a1-2-4) is more preferable, and the structural unit represented by the formula (a1-2-3) is more preferable.

  When the resin (A) has the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is based on the total structural unit (100 mol%) of the resin (A). The range of 10-95 mol% is preferable, the range of 15-90 mol% is more preferable, the range of 20-85 mol% is further more preferable, and the range of 20-60 mol% is still more preferable. When the structural unit (a1) has a structural unit (a1) having an adamantyl group (preferably the structural unit (a1-1)), the total of structural units (a1) in the resin (A) ( 100 mol%), the structural unit (a1) having an adamantyl group is preferably 15 mol% or more. With such a content ratio, the resin (A) having the structural unit (a1) having an adamantyl group tends to have good dry etching resistance of a resist pattern produced from the resist composition containing the resin (A). There is. In addition, in order to make the total content rate of a structural unit (a1-1) and / or a structural unit (a1-2) into the above-mentioned range, when manufacturing resin (A), it is with respect to the usage-amount of all monomers. What is necessary is just to adjust the usage-amount of the monomer which induces | guides | derives a structural unit (a1-1) and / or a structural unit (a1-2).

  The structural unit (a1-1) and the structural unit (a1-2), which are preferable structural units (a1), have been described above. However, the resin (A) has a structural unit (a1) other than these. May be. Hereinafter, the structural unit (a1) other than the structural unit (a1-1) and the structural unit (a1-2) will be described with reference to a monomer that derives the structural unit (a1).

［式（ａ１−３）中、Ｒ^a9は、水素原子、置換基（例えばヒドロキシ基）を有していてもよい炭素数１〜３の脂肪族炭化水素基、カルボキシ基、シアノ基、又は−ＣＯＯＲ^a13で表される基を表し、Ｒ^a13は、炭素数１〜８の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子はヒドロキシ基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。Ｒ^a10、Ｒ^a11及びＲ^a12は、それぞれ独立に、炭素数１〜１２の脂肪族炭化水素基を表すか、或いはＲ^a10及びＲ^a11は互いに結合して環を形成している。該脂肪族炭化水素基及に含まれる水素原子はヒドロキシ基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。］ The resin (A) may have a structural unit (a1) derived from a monomer represented by the following formula (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”). Good. In the resin (A) having the structural unit (a1) derived from the monomer (a1-3), the structural unit (a1) contains a rigid norbornane ring in the main chain of the resin (A). This resist composition containing such a resin (A) tends to be able to produce a resist pattern having excellent dry etching resistance.

[In Formula (a1-3), R ^a9 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a substituent (for example, a hydroxy group), a carboxy group, a cyano group, or — ^Represents a group represented by COOR ^a13 , R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like The methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. R ^a10 , R ^a11 and R ^a12 each independently represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or R ^a10 and R ^a11 are bonded to each other to form a ring. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The aliphatic hydrocarbon group which may have a substituent of R ^a9 is typically an alkyl group which may have a substituent, and among these alkyl groups, an alkyl having no substituent The group includes those already exemplified in the range of 1 to 8 carbon atoms. Examples of the substituent, particularly the aliphatic hydrocarbon group (alkyl group) having a hydroxy group include a hydroxymethyl group and a 2-hydroxyethyl group. ^Examples of R ^a13 include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.

The aliphatic hydrocarbon groups of R ^{a10 to} R ^a12 are also typically alkyl groups, and specific examples thereof are the same as those of R ^a9 . The ring formed by combining R ^a10 and R ^a11 together with the carbon atom to which they are bonded includes a cyclohexyl ring and an adamantyl ring.

As a monomer (a1-3), what was described in Unexamined-Japanese-Patent No. 2010-204646 is used, for example. Among these, a monomer represented by any one of the following formulas (a1-3-1) to (a1-3-4) is preferable, and the formula (a1-3-2) or (a1-3-4) Is more preferable, and a monomer represented by formula (a1-3-2) is more preferable.

  When the resin (A) has a structural unit derived from the monomer (a1-3), the content ratio is in the range of 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (A). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.

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

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

Among “an alkyl group having 1 to 6 carbon atoms which may have a halogen atom”, the alkyl group includes those already exemplified in the range of 1 to 6 carbon atoms. As the alkyl group having a halogen atom, an alkyl group having a fluorine atom is preferable. For example, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert- Examples thereof include a butyl group, a perfluoropentyl group, and a perfluorohexyl group. Among these, as R < ¹⁰ >, a C1-C4 alkyl group is preferable, a methyl group and an ethyl group are more preferable, and a methyl group is further more preferable.
The alkoxy group of R ¹¹ includes those already exemplified in the range of 1 to 6 carbon atoms. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is further preferable. .
The acyl group and acyloxy group of R ¹¹ include those already exemplified in the range of 2 to 4 carbon atoms.
The hydrocarbon groups of R ¹² and R ¹³ are those having 1 to 12 carbon atoms, and the hydrocarbon group of Y ^a3 is the aliphatic hydrocarbon group exemplified above in the range of 1 to 18 carbon atoms. Contains any of the aromatic hydrocarbon groups.
The aliphatic hydrocarbon group for X ^a2 is a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, or a divalent group in which a chain hydrocarbon group and an alicyclic hydrocarbon group are combined. And groups already exemplified in the range of 1 to 17 carbon atoms, and groups obtained by appropriately combining those already exemplified.

As a monomer (a1-4), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. A monomer represented by any of the following formulas (a1-4-1) to (a1-4-7) is preferred, and any one of formulas (a1-4-1) to (a1-4-5) The monomer represented by is more preferable.

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

式（ａ１−５）中、
Ｒ^３１は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｌ^３〜Ｌ^５は、オキシ基、チオキシ基又は＊−Ｏ−（ＣＨ₂）_k４−ＣＯ−Ｏ−で表される基を表す。ここで、ｋ４は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手である。
Ｚ^１’は、単結合又は炭素数１〜６のアルカンジイル基であり、該アルカンジイル基中に含まれるメチレン基は、オキシ基又はカルボニル基に置き換わっていてもよい。
ｓ１及びｓ１’は、それぞれ独立して、０〜４の整数を表す。 As the other monomer (a1), for example, a monomer represented by the formula (a1-5) which is a (meth) acrylic monomer having an acid labile group (2) (hereinafter referred to as “monomer (a1-5)”) May be used).

In formula (a1-5),
R ³¹ represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
L ^{3 to} L ⁵ represent a group represented by an oxy group, a thioxy group, or * —O— (CH ₂ ) _k4 —CO—O—. Here, k4 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
Z ^{1 ′} is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxy group or a carbonyl group.
s1 and s1 ′ each independently represents an integer of 0 to 4.

In formula (a1-5), R ³¹ is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ⁵ is preferably an oxygen atom.
One of L ³ and L ⁴ is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^{1 ′} is preferably a single bond or —CH ₂ —CO—O—.

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

  When the resin (A) has a structural unit derived from the monomer (a1-5), the content thereof is in the range of 1 to 95 mol% with respect to all the structural units (100 mol%) of the resin (A). Is preferable, the range of 3-90 mol% is more preferable, and the range of 5-85 mol% is further more preferable.

<Acid stable structural unit>
Resin (A) is a structural unit not having an acid labile group in addition to a structural unit (a1) having an acid labile group (hereinafter, sometimes referred to as “acid stable structural unit”). The derivatizable monomer is preferably referred to as “acid-stable monomer”). In the resin (A), the acid stable structural unit may have only one type, or may have a plurality of types.

  When the resin (A) has an acid stable structural unit, the content ratio of the acid stable structural unit may be determined based on the content 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 It is 20 mol%, More preferably, it is 20-60 mol% / 80-40 mol%. 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 still better.

Next, a preferable thing is demonstrated among an acid stable structural unit.
The acid stable structural unit is preferably a structural unit having a hydroxy group or a lactone ring. An acid stable structural unit having a hydroxy group (hereinafter sometimes referred to as “acid stable structural unit (a2)”) and / or an acid stable structural unit having a lactone ring (hereinafter referred to as “acid stable structural unit (a3)”). The resin (A) having a composition) may be a coating film formed on the substrate or a composition layer obtained from the coating film when the resist composition containing the resin (A) is applied to the substrate. Therefore, the resist pattern can be manufactured with good resolution. In addition, the manufacturing method of the resist pattern using this resist composition here is mentioned later. First, the acid stable structural unit (a2) and the acid stable structural unit (a3) suitable as the acid stable structural unit will be described with specific examples.

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

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

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

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

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

  As described above, the exemplified acid stable structural unit (a2-1) is derived from, for example, an acid stable monomer described in JP 2010-204646 A. Among these, the acid stable structural unit represented by any one of formula (a2-1-1), formula (a2-1-2), formula (a2-1-3) and formula (a2-1-4) (A2-1) is more preferable, and the acid stable structural unit (a2-1) represented by the formula (a2-1-1) or (a2-1-3) is more preferable.

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

式（ａ２−０）中、
Ｒ^a30は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^a31の全部又は一部は同じであってもよい。 Next, the acid stable structural unit which has a phenolic hydroxy group among the acid stable structural units which have a hydroxy group is demonstrated. The acid stable structural unit is preferably one 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, all or some of the plurality of R ^a31 may be the same.

Specific examples of the “alkyl group having 1 to 6 carbon atoms” in the “alkyl group having 1 to 6 carbon atoms which may have a halogen atom” for R ^a30 include those already exemplified in this range. . The “C 1-6 alkyl group having a halogen atom” is one in which at least a part of the hydrogen atoms contained in the C 1-6 alkyl group is substituted with a halogen atom. The specific example of the halogen atom is as already described. 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.
Specific examples of the alkoxy group of R ^a31 include those already exemplified in the range of 1 to 6 carbon atoms. Among these, R ^a31 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group and 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.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.

Among the acid stable structural units (a2-0), the following formulas (a2-0-1), (a2-0-2), (a2-0-3) and (a2-0-4) Those represented by either are preferred. The monomer (a1) capable of deriving such a structural unit is described in, for example, JP 2010-204634 A.

  Acid-stable monomer capable of deriving acid-stable structural unit (a2-0) such as p-hydroxystyrene and p-hydroxy-α-methylstyrene [hereinafter referred to as “acid-stable monomer (a2)” in some cases. ] In the production of the resin (A), the acid stable structural unit (a2-0) represented by the formula (a2-0-1) or the formula (a2-0-2) is converted into the resin (A). After the phenolic hydroxy group in the acid stable monomer (a2) is protected with a protecting group such as an acetyl group to form a protected acid stable monomer (a2), the protected acid Resin (A) can also be manufactured using a stable monomer (a2). A resin (A) having an acid-stable structural unit (a2-0) is produced by deprotecting a resin having a structural unit derived from the protected acid-stable monomer (a2), thereby removing the protecting group. it can. However, when carrying out the deprotection treatment, it is necessary to carry out the deprotection treatment without significantly damaging the structural unit (a1).

  When the resin (A) has an acid stable structural unit (a2-0), the content is preferably in the range of 5 to 90 mol%, and preferably 10 to 85 mol% with respect to all the structural units of the resin (A). Is more preferable, and the range of 15 to 80 mol% is particularly preferable.

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

［式（ａ３−１）中、
Ｌ^a4は、酸素原子又は＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）を表す。＊はカルボニル基との結合手を表す。
Ｒ^a18は、水素原子又はメチル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a21は炭素数１〜４の脂肪族炭化水素基を表し、ｐ１が２以上の場合、複数のＲ^a21の全部又は一部は同じであってもよい。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は＊−Ｏ−（ＣＨ₂）_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の全部又は一部は同じであってもよい。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は＊−Ｏ−（ＣＨ₂）_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の全部又は一部は同じであってもよい。］ The acid stable structural unit (a3) is preferably one represented by the following formula (a3-1), formula (a3-2) or formula (a3-3). Resin (A) may have only 1 type among these, and may have 2 or more types. In the following description, the formula (a3-1) may be referred to as “acid-stable structural unit (a3-1)”, and the formula (a3-2) may be referred to as “acid-stable structure”. “Unit (a3-2)” may be referred to, and the compound represented by formula (a3-3) may be referred to as “acid-stable structural unit (a3-3)”.

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

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 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 and * —O—CH ₂ —CO—O— is more preferable, and an oxygen atom is more preferable.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are preferably integers of 0 to 2, more preferably 0 or 1. When p1 is 2, two R ^a21 may be the same as or different from each other. When q1 is 2, two R ^a22 may be the same as or different from each other, and r1 is 2. Two R ^a23 may be the same or different from each other.

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

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

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

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

  In addition, as an acid stable monomer which can derive | lead out this acid stable structural unit (a3), what was described in Unexamined-Japanese-Patent No. 2010-204646 can be mentioned, for example.

When the resin (A) has an acid stable structural unit (a3), the total content is preferably in the range of 5 to 70 mol% with respect to all the structural units (100 mol%) of the resin (A). The range of 10 to 65 mol% is more preferable, and the range of 10 to 60 mol% is more preferable.
The content of each of the structural unit derived from the monomer (a3-1), the structural unit derived from the monomer (a3-2), and the structural unit derived from the monomer (a3-3) is the total structure of the resin (A). 5-60 mol% is preferable with respect to a unit (100 mol%), the range of 5-50 mol% is more preferable, and the range of 10-50 mol% is more preferable.

  As described above, the structural unit (a1-1) or the structural unit (a1-2) suitable as the structural unit (a1) of the resin (A), the acid stable structural unit (a2) or the acid stable structure suitable as the acid stable structural unit. Although the unit (a3) has been described in detail, structural units other than these may be included, and examples of the structural unit include structural units well known in the art. Although the resin (A) having an acid labile group in the molecule has been described here, the resist composition may contain a resin having no acid labile group.

<Method for producing resin (A)>
The resin (A) is obtained by copolymerizing the monomer (a1) for deriving the structural unit (a1), more preferably the monomer (a1) and an acid stable monomer for deriving the acid stable structural unit. More preferably, the monomer (a1) for deriving the structural unit (a1-1) and / or the structural unit (a1-2), and the acid-stable structural unit (a2) and / or the acid-stable structural unit (a3) are derived. Copolymerized with an acid stable monomer. For example, when the resist composition is used for EUV exposure, the monomer (a1) that induces the structural unit (a1-1) and / or the structural unit (a1-2), and the acid stable structural unit (a2- And an acid-stable monomer derived from 0).
The resin (A) further preferably has a structural unit (a1-1) having an adamantyl group as the structural unit (a1). The resin (A) can be produced by subjecting the monomer as described above to a known polymerization method (for example, radical polymerization method) and polymerizing (copolymerizing) it.

  The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more), 30,000 or less (more preferably 15,000 or less, still more preferably 1,000 or less, particularly preferably Is 6,000 or less). In addition, the weight average molecular weight here is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis. Detailed analysis conditions for this analysis are described in the Examples of the present application.

<Acid generator (B)>
Next, the acid generator (B) contained in the resist composition will be described.
The acid generator (B) is an acid generator composed of a sulfonium salt or an iodonium salt, and examples of the anion of the acid generator (B) include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

［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、単結合又は炭素数１〜１７の脂肪族飽和炭化水素基を表し、該脂肪族飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該アルキル基及び該脂環式炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよい。
Ｚ⁺は、有機スルホニウムカチオン又は有機ヨードニウムカチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, more preferably an acid generator represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”). .

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the aliphatic saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. The methylene group constituting the alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group.
Z ⁺ represents an organic sulfonium cation or an organic iodonium cation. ]

Specific examples of the perfluoroalkyl group of Q ¹ and Q ² include those in which all of the hydrogen atoms constituting the alkyl group are replaced by fluorine atoms in the alkyl group having 1 to 6 carbon atoms among the already exemplified alkyl groups. Applicable. Specifically, for example, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, etc. Can be mentioned.
As the acid generator (B1) contained in the resist composition, Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom acid generator (B1). Q ¹ and Q ² An acid generator (B1) in which both are fluorine atoms is more preferred.

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、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b3及びＬ^b4の合計炭素数の上限は１３である。
Ｌ^b5は、炭素数１〜１５の２価の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の２価の脂肪族炭化水素基を表し、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b6及びＬ^b7の合計炭素数の上限は１６である。
Ｌ^b8は、炭素数１〜１４の２価の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b9及びＬ^b10は、それぞれ独立に、炭素数１〜１１の２価の脂肪族炭化水素基を表し、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b9及びＬ^b10の合計炭素数の上限は１２である。
本レジスト組成物に含有される酸発生剤（Ｂ）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。 An example in which the methylene group constituting the aliphatic hydrocarbon group of L ^b1 is replaced with an oxygen atom or a carbonyl group is represented by any of the following formulas (b1-1) to (b1-6). Groups. Incidentally, the formula (b1-1) ~ formula (b1-6) has its left and right are described in accordance with the formula (B1), * represents a bonding hand, the left bond is C (Q ¹⁾ It is bonded to the carbon atom of (Q ² ), and the right bond is bonded to Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).

In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or a C 1-15 divalent aliphatic hydrocarbon group, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b3 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b4 represents a divalent aliphatic hydrocarbon group having 1 to 13 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b6 and L ^b7 each independently represent a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a divalent aliphatic hydrocarbon group having 1 to 14 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b9 and L ^b10 each independently represent a divalent aliphatic hydrocarbon group having 1 to 11 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.
Among these, the acid generator (B1) contained in the resist composition is preferably an acid generator (B1) having a divalent group represented by the formula (b1-1) as L ^{b1. The} acid generator (B1) having a divalent group represented by the formula (b1-1) where ^b2 is a single bond or a methylene group as L ^b1 is more preferable.

L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4), more preferably any one of formulas (b1-1) to (b1-3). And more preferably a group represented by the formula (b1-1).

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.

As above-mentioned, Y represents the C1-C18 aliphatic hydrocarbon group which may have a substituent. Among these aliphatic hydrocarbon groups, Y is preferably an alkyl group and an alicyclic hydrocarbon group, more preferably an alkyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, More preferred are 3-12 alicyclic hydrocarbon groups.
When the aliphatic hydrocarbon group of Y has a substituent, the substituent is, for example, a halogen atom (excluding a fluorine atom), a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic having 6 to 18 carbon atoms. Group represented by a group hydrocarbon group, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group or — (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 (divalent 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 with an oxygen atom, a sulfonyl group or a carbonyl group include, for example, a cyclic ether group (one or two of the methylene groups constituting 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 constituting an alicyclic hydrocarbon group are replaced by a carbonyl group), a sultone ring group (which constitutes an alicyclic hydrocarbon group) Two adjacent methylene groups in the methylene group are replaced with oxygen atoms and sulfonyl groups, respectively, and a lactone ring group (two methylene groups adjacent in the methylene group constituting the alicyclic hydrocarbon group, A group in which an oxygen atom and a carbonyl group are substituted, respectively).

これらの中でも、好ましくは式（Ｙ１）〜式（Ｙ１９）及び式（Ｙ２７）〜式（Ｙ２９）のいずれかで表される基であり、より好ましくは式（Ｙ１１）、式（Ｙ１４）、式（Ｙ１５）、式（Ｙ１９）、式（Ｙ２７）、式（Ｙ２８）及び式（Ｙ２９）のいずれかで表される基であり、さらに好ましくは式（Ｙ１１）又は式（Ｙ１４）で表される基である。 In particular, examples of the alicyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y29).

Among these, Preferably it is group represented by either of Formula (Y1)-Formula (Y19) and Formula (Y27)-Formula (Y29), More preferably, Formula (Y11), Formula (Y14), Formula (Y15), formula (Y19), formula (Y27), group represented by formula (Y28) and formula (Y29), more preferably represented by formula (Y11) or formula (Y14). It is a group.

Examples of Y include the following.

  As already explained, the alicyclic hydrocarbon group of Y is preferably a group having an adamantane ring as shown in formulas (Y1) and (Y2), and when these have a substituent, Is preferably a hydroxy group or an oxo group. That is, as the alicyclic hydrocarbon group having a substituent, a hydroxyadamantyl group and an oxoadamantyl group are particularly preferable as Y.

Specific examples of the sulfonate anion include sulfonate anions represented by any one of the formulas (b1-1-1) to (b1-1-1-9). In the sulfonate anion represented by any one of formulas (b1-1-1) to (b1-1-1-9), L ^b1 is preferably a group represented by formula (b1-1). R ^b2 and R ^b3 are each independently defined as a substituent that may optionally be present in the aliphatic hydrocarbon group of Y, preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms, A methyl group is more preferred.

  Specific examples of the sulfonate anion represented by any one of the formulas (b1-1-1) to (b1-1-9) include sulfonate anions described in JP 2010-204646 A, for example. be able to.

Hereinafter, as a preferable sulfonate anion, L ^b1 is a group represented by the formula (b1-1), and Y is an alicyclic hydrocarbon group represented by the formula (Y1) or the formula (Y2). A specific example is given. Examples of the sulfonate anion in which Y is an unsubstituted alicyclic hydrocarbon group include those represented by any of the following formulas (b1-s-1) to (b1-s-9).

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

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

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

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

Y may be an alkyl group. Examples of such a sulfonate anion include those represented by the following formula (b1-s-42).

The cation (Z ⁺ ) contained in the acid generator (B) is an organic sulfonium cation or an organic iodonium cation, preferably an organic sulfonium cation, and more preferably an arylsulfonium cation.

Z ⁺ in formula (B1) is preferably represented by any of formula (b2-1) to formula (b2-4).

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

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

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

Preferred examples of the alkyl group ^{represented by} R ^{b9 to} R ^b12 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, and an octyl group. And 2-ethylhexyl group.
Preferable examples of the alicyclic hydrocarbon group represented by R ^{b9 to} R ^b11 include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyladamantan-2-yl group, 1- ( Adamantan-1-yl) alkane-1-yl group and isobornyl group.
Preferred examples of the aromatic hydrocarbon group for R ^b12 include phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, And biphenylyl and naphthyl groups.
A group in which an aromatic hydrocarbon group of R ^b12 and an alkyl group are bonded is typically an aralkyl 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.

  Specific examples of the sulfonium cation and the iodonium cation include those described in JP 2010-204646 A.

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。また、Ｒ^b19〜Ｒ^b21から選ばれる２つが一緒になってヘテロ原子を有してもよい環を形成してもよい。
該脂肪族炭化水素基の炭素数は１〜１２であると好ましく、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く、さらには置換基として、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の全部又は一部は同じであってもよく、ｗ２が２以上のとき、複数のＲ^b20の全部又は一部は同じであってもよく、ｘ２が２以上のとき、複数のＲ^b21の全部又は一部は同じであってもよい。
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。 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)”. ], 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. It is also possible to form two of which may have a hetero atom together ring selected from R ^b19 to R ^b21.
The aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms and an alicyclic hydrocarbon group having 4 to 18 carbon atoms. You may have an atom, a hydroxy group, a C1-C12 alkoxy group, a C6-C18 aromatic hydrocarbon group, a C2-C4 acyl group, or a glycidyloxy group.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, all or some of the plurality of R ^b19 may be the same, and when w2 is 2 or more, all or some of the plurality of R ^b20 may be the same, and x2 is When two or more, all or some of the plurality of R ^b21 may be the same.
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 a group.

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

  The acid generator (B1) is preferably a salt represented by the formula (B1-1) to the formula (B1-22), more preferably a formula containing a triphenylsulfonium cation or a tolylsulfonium cation. (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1-11), Formula (B1-12), Formula ( And salts represented by formula (B1-13), formula (B1-14), and formula (B1-21).

The content of the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably 25 parts by mass) with respect to 100 parts by mass of the resin (A). Part or less).
In the resist composition of the present invention, the acid generator (B) may contain a single acid generator or a plurality of acid generators.

<Basic compound (C)>
The resist composition can produce a resist pattern having excellent CD uniformity by containing the salt (X). Furthermore, it is possible to manufacture a resist pattern having an excellent mask error factor. In addition to the salt (X), the present resist composition further contains a basic compound (C) different from the salt (X), in particular, the basic compound (C) functioning as the quencher described above. Also good.

  The basic compound (C) is preferably a basic amine, an ammonium salt or a combination thereof. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by the formula (C1) to the formula (C8), more preferably a compound represented by the formula (C1-1).

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

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

［式（Ｃ１−１）中、
Ｒ^c2及びＲ^c3は、前記と同義である。
Ｒ^c4は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4の全部又は一部は同じであってもよい。］

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

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、
Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同義である。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9の全部又は一部は同じであってもよい。］

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

［式（Ｃ５）及び式（Ｃ６）中、
Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、それぞれ独立に、Ｒ^c1と同義である。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同義である。
ｏ３及びｐ３は、それぞれ独立に０〜３の整数を表し、ｏ３が２以上であるとき、複数のＲ^c14の全部又は一部は同じであってもよい。ｐ３が２以上であるとき、複数のＲ^c15の全部又は一部は同じであってもよい。
Ｌ^c1は、炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

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

［式（Ｃ７）及び式（Ｃ８）中、
Ｒ^c18、Ｒ^c19及びＲ^c20は、それぞれ独立に、Ｒ^c4と同義である。
ｑ３、ｒ３及びｓ３は、それぞれ独立に０〜３の整数を表し、ｑ３が２以上であるとき、複数のＲ^c18の全部又は一部は同じであってもよい。ｒ３が２以上であるとき、複数のＲ^c19の全部又は一部は同じであってもよい。ｓ３が２以上であるとき、複数のＲ^c20の全部又は一部は同じであってもよい。 Ｌ^c2は、単結合又は炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

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

  Examples of the compound represented by the formula (C1) include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2- Examples include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, and 4,4′-diamino-3,3′-diethyldiphenylmethane. Isopropyl aniline, and more preferably include include 2,6-diisopropylaniline.

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

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

<Solvent (D)>
If necessary, the solvent (D) contained in the resist composition includes the type and amount of the salt (X) and resin (A) used, the acid generator (B) [particularly, the acid generator (B1). )]], And in the production of a resist pattern, which will be described later, it is possible to appropriately select an optimal one from the viewpoint of good applicability when the resist composition is applied on a substrate. it can.

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

<Other ingredients>
The resist composition may contain components other than the salt (X), the resin (A), the acid generator (B), and the solvent (D) and the basic compound (C) used as necessary. Good. This component may be referred to as “component (F)”. Examples of the component (F) include additives known in the art, for example, polymer compounds other than the resin (A), sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes.

<Preparation method of the present resist composition>
The present resist composition can be usually prepared by mixing the salt (X), the resin (A) and the acid generator (B) in the presence of the solvent (D). Furthermore, you may mix a basic compound (C) and / or a component (F) as needed as above-mentioned. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select the suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to solvent (D), such as a kind (resin (A)), such as resin (A). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
By selecting the amount of each component used when preparing the resist composition of the present invention, the content of each component in the resist composition of the present invention can be adjusted.

  The content ratio of the salt (X) in the resist composition is preferably 10% by mass or less, more preferably 8% by mass or less, and still more preferably 5% by mass or less, based on the solid content of the resist composition. Preferably it is 0.001 mass% or more, More preferably, it is 0.01 mass% or more, More preferably, it is 0.05 mass% or more. In addition, solid content here means what remove | excluded the solvent (D) from this resist composition. The solid content can be determined by subjecting the resist composition to analysis such as liquid chromatography and gas chromatography.

  A preferable range of the content ratio of the resin (A) in the resist composition is determined based on the solid content of the resist composition. Specifically, the resin (A) is preferably 80% by mass or more and 99% by mass or less based on the mass of the solid content.

  The content rate of the acid generator (B) in this resist composition is set to a preferable range with respect to the content of the resin (A). Specifically, the acid generator (B) is preferably 1% by mass or more, more preferably 3% by mass or more, and preferably 40% by mass or less, more preferably based on the content of the resin (A). Is 35% by mass or less.

  When the basic compound (C) is contained in the resist composition, the content ratio is preferably about 0.01 to 5% by mass with respect to the solid content of the resist composition, more preferably 0.8. It is about 01 to 3% by mass, particularly preferably about 0.01 to 1% by mass. In addition, when this basic composition (C) is contained in this resist composition, it is also preferable to determine content of a basic compound (C) on the basis of content of salt (X). Specifically, the content of the basic compound (C) is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and still more preferably with respect to 100 parts by mass of the total content of the salt (X). 100 parts by mass or less. When the basic composition (C) is contained in the resist composition, the total content of the basic compound (C) and the salt (X) is preferably 2 mass in the solid content of the resist composition. % Or less, more preferably 1% by mass or less.

  The content ratio of the solvent (D) in the present resist composition is 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, based on the total amount of the present resist composition. It is 9 mass% or less, Preferably it is 99 mass% or less.

  When the resist composition contains the component (F), the appropriate content can be adjusted according to the type of the component (F).

  Thus, preferable content of each of the salt (X), the resin (A), the acid generator (B) and the solvent (D), and the basic compound (C) or the component (F) used as necessary. It is preferable to filter using a filter having a pore size of about 0.01 to 0.2 μm.

<Method for producing resist pattern>
Specifically showing a method for producing a resist pattern using the present resist composition,
(1) a step of applying the resist composition on a substrate;
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating. 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 the present 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 can be washed or an antireflection film can 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 present resist composition coated on the substrate, that is, the coated film is dried to remove the solvent (D). In the drying, for example, the solvent (D) is evaporated from the coating film by a heating means using a heating device such as a hot plate (so-called pre-baking), a decompression means using a decompression device, or a combination of these means. Is done. The drying conditions can be selected according to the type of the solvent (D) contained in the resist composition. For example, in a heating means using a hot plate, the surface temperature of the hot plate is set in the range of about 50 to 200 ° C. Preferably it is done. In the decompression means, it is preferable to enclose the substrate on which the coating film is formed in an appropriate decompressor, and then set the internal pressure of the decompressor to about 1 to 1.0 × 10 ⁵ Pa. Thus, by removing the solvent (D) from the coating film, a composition layer is formed on the substrate.

Step (3) is a step of exposing the composition layer, and preferably a step of exposing the composition layer using an exposure machine. The exposure is performed through a mask (photomask) on which a desired 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 those that emit laser light from a far ultraviolet region or a vacuum ultraviolet region by converting the wavelength of laser light from a semiconductor laser or the like can be used. The exposure machine may be an immersion exposure machine. The exposure machine may irradiate an electron beam or extreme ultraviolet light (EUV). In this specification, irradiating these radiations may be collectively referred to as “exposure”.
By exposing through a mask, the composition layer has an exposed portion (exposed portion) and an unexposed portion (unexposed portion). In the composition layer of the exposed portion, the acid generator (acid generator (B)) contained in the composition layer receives an exposure energy to generate an acid, and is further in the resin (A) by the action of the generated acid. Since the acid labile group is rendered hydrophilic by the deprotection reaction, the resin (A) in the composition layer in the exposed area becomes soluble in the 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. The solubility of the composition layer in the exposed area and the composition layer in the unexposed area are significantly different from each other in the aqueous alkali solution.

  In step (4), the composition layer after exposure is subjected to heat treatment (so-called post-exposure baking). Such heat treatment is preferably the heating means using the hot plate shown in the step (2). In addition, when performing the heating means using a hot plate in the step (4), the surface temperature of the hot plate is preferably about 50 to 200 ° C, more preferably about 70 to 150 ° C. The deprotection reaction is promoted by the heat treatment.

Step (5) is a step of developing the heated composition layer, and preferably the heated composition layer is developed with 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 resist pattern is preferably rinsed with ultrapure water or the like. Furthermore, it is preferable to remove moisture remaining on the substrate and the resist pattern.

  According to the resist pattern manufacturing method including the steps (1) to (5) as described above, the resist composition can manufacture a resist pattern having excellent CD uniformity. Moreover, this resist composition can also exhibit the effect that the resist pattern excellent in the mask error factor can be manufactured, for example.

<Application>
As described above, the resist composition is suitable not only as a resist composition for electron beam lithography (EB) or EUV exposure, but also as a resist composition for KrF excimer laser exposure and for ArF excimer laser exposure. It is also suitable as a resist composition.

Hereinafter, the present invention will be described in detail by way of examples.
In Examples and Comparative Examples, “%” and “part” representing the content and the amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography (HLC-8120GPC type manufactured by Tosoh Corporation) using polystyrene as a standard product.
Column: TSKgel G4000H _XL + TSKgel G2000H _XL
+ 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)

これらのモノマーはすでに説明したものであるが、以下、その式番号に応じて「モノマー（ａ１−１−２）」などという。 The monomer used for manufacture of resin (A) is shown below.

These monomers have already been described, and are hereinafter referred to as “monomer (a1-1-2)” depending on the formula number.

Synthesis Example 1 [Synthesis of Resin A1]
As the monomer, using monomer (a1-1-3), monomer (a1-2-3), monomer (a2-1-1), monomer (a3-1-1) and monomer (a3-2-3), The molar ratio (monomer (a1-1-3): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-1-1): monomer (a3-2-3)) It mixed so that it might become 30: 14: 6: 20: 30, and 1.5 mass times dioxane of the total monomer amount was added, and it was set as the solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice, and the weight average molecular weight was 8. 1 × 10 ³ resin A1 (copolymer) was obtained with a yield of 65%. This resin A1 has the following structural units.

Synthesis Example 2 [Synthesis of Resin A2]
As the monomer, monomer (a1-1-2), monomer (a2-1-1) and monomer (a3-1-1) were used, and the molar ratio (monomer (a1-1-2): monomer (a2-1) -1): The monomer (a3-1-1)) was mixed so as to be 50:25:25, 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, based on the total monomer amount, and these are heated at 80 ° C. for about 8 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 resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 9. 2 × 10 ³ resin A2 (copolymer) was obtained with a yield of 60%. This resin A2 has the following structural units.

Synthesis Example 3 [Synthesis of Resin A3]
As the monomer, using monomer (a1-1-3), monomer (a1-2-3), monomer (a2-1-1), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio (monomer (a1-1-3): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-2-3): monomer (a3-1-1)) , 30: 14: 6: 20: 30, and 1.5 mass times dioxane of the total monomer amount was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.0. A × 10 ³ resin A3 (copolymer) was obtained in a yield of 60%. This resin A3 has the following structural units.

Synthesis Example 4 [Synthesis of Resin A4]
As the monomer, using monomer (a1-1-3), monomer (a1-5-1), monomer (a2-1-1), monomer (a3-2-3) and monomer (a3-1-1), The molar ratio (monomer (a1-1-3): monomer (a1-5-1): monomer (a2-1-1): monomer (a3-2-3): monomer (a3-1-1)) , 30: 14: 6: 20: 30, and 1.5 mass times dioxane of the total monomer amount was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.4. × 10 ³ of the resin A4 (copolymer) was obtained in 62% yield. This resin A4 has the following structural units.

Examples 1 to 10 and Comparative Example 1
The components shown in Table 1 below were mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

Ｂ１−２１（特開２００７−１６１７０７号公報記載の方法に従って合成）：

<Resin (A)>
Resin A1 to Resin A4
<Acid generator (B)>
B1-3 (synthesized according to the method described in JP2010-152341A):

B1-21 (synthesized according to the method described in JP 2007-161707 A):

化合物Ｘ１１（国際公開第２００７／０４５３８６号記載の方法に従って合成）：

化合物Ｘ２１（Ａｌｄｌｉｃｈより入手）：

<Salt (X)>
Compound X1 (obtained from Tokyo Kasei):

Compound X11 (synthesized according to the method described in WO2007 / 045386):

Compound X21 (obtained from Aldrich):

<Basic compound (C)>
Basic compound C1: 2,6-diisopropylaniline (obtained from Tokyo Kasei)

<Solvent>
Propylene glycol monomethyl ether acetate 265 parts 2-heptanone 20.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.5 parts

An organic antireflection film having a thickness of 780 mm is formed by applying a composition for organic antireflection film (ARC-29; manufactured by Nissan Chemical Co., Ltd.) to a silicon wafer and baking it at 205 ° C. for 60 seconds. 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. The silicon wafer coated with the resist composition was pre-baked on a direct hot plate at a temperature described in the “PB” column of Table 1 for 60 seconds to form a resist film. ArF excimer stepper for immersion exposure (XT: 1900Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light) on a silicon wafer on which a resist film is formed, and a contact hole pattern (hole pitch 100 nm / Using a mask for forming a hole diameter of 70 nm, exposure was performed while changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, the silicon wafer was post-exposure baked on a hot plate at a temperature described in the “PEB” column of Table 1 for 60 seconds. Next, this silicon wafer was subjected to paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution to obtain a resist pattern.

  In each resist film, an exposure amount at which the hole diameter of a pattern formed with a mask having a hole diameter of 70 nm was 55 nm was defined as effective sensitivity.

<Evaluation of CD uniformity (CDU)>
In terms of effective sensitivity, the resist pattern formed using the mask was evaluated as follows. 24 hole diameters were measured for each hole, and the average value was taken as the average hole diameter of one hole. For the same resist pattern, the same average hole diameter measurement was performed at 400 locations, and the standard deviation was determined using them as a population to obtain the CDU. It can be said that the smaller this value, the better the CD uniformity of the resist pattern.
These results are shown in Table 2.

<Evaluation of mask error factor (MEF)>
In terms of effective sensitivity, the slope of a straight line when plotting the mask hole diameter on the horizontal axis and the hole diameter of each pattern on the vertical axis of a pattern formed with a mask having a hole diameter of 72 nm, 71 nm, 70 nm, 69 nm, and 68 nm, respectively. Calculated as MEF. It can be said that the smaller this value, the better the mask error factor of the resist pattern.
These results are shown in Table 2.

  If the resist composition of the present invention is used, a resist pattern having excellent CD uniformity (CDU) can be produced, which is useful for fine processing of semiconductors.

Claims (9)

A resist composition containing the following (A), (B) and (X).
(A) a resin that is insoluble or hardly soluble in an alkaline aqueous solution and can be dissolved in an alkaline aqueous solution by the action of an acid;
(B) an acid generator comprising a sulfonium salt or an iodonium salt,
(X) a salt represented by the formula (I)

[In the formula (I),
L ¹ and L ² each independently represent an alkanediyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkanediyl group is an oxygen atom, —NR ⁵ — (R ⁵ is a hydrogen atom or carbon Represents an alkyl group of 1 to 6) or a carbonyl group, and a hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a hydroxy group.
R ² and R ³ each independently represent an alkyl group having 1 to 6 carbon atoms.
R ⁴ represents SO ₃ ⁻ , CO ₂ ^— or O ⁻ .
W is the formula (W-I)

(In the formula (W-I),
n represents an integer of 0 to 6.
R ¹ represents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and a methylene group constituting the monovalent aliphatic hydrocarbon group. May be replaced by an oxygen atom or a carbonyl group.
When n is 2 or more, all or a part of the plurality of R ¹ may be the same.
The methylene group constituting the ring may be replaced with an oxygen atom or a carbonyl group.
The dotted line represents that the bond including the dotted line may be a single bond or a double bond.
m represents an integer of 1 to 5.
* Is a bond to ^{L 1.} )
It is group represented by these. ] The resist composition according to claim 1, wherein L ¹ in the formula (I) is a group represented by the following formula (I-1).

(In the formula (I-1),
R ⁶ and R ⁷ represent an alkanediyl group which may have a hydroxy group, and the total carbon number of R ⁶ and R ⁷ is in the range of 2 to 10.
Two * 's represent a bond, the left * is a bond with W, and the * on the right is a bond with a nitrogen atom. ) L ^{1 in the} formula (I) is
* —CH (CH ₃ ) —CH ₂ —CH ₂ —CO—NH— (CH ₂ ) _o — *
(Two * 's represent a bond, the left * represents a bond with W, and the right * represents a bond with a nitrogen atom. O represents an integer of 1 to 6.)
The resist composition according to claim 1. L ^{2 in the} formula (I) is
*-(CH ₂ ) _l- *
(Two * 's represent a bond, and l represents an integer of 1 to 12. The methylene group constituting this group may be replaced by an oxygen atom or a carbonyl group, and the hydrogen atom contained in the methylene group is , May be replaced by a fluorine atom or a hydroxy group.)
The resist composition according to any one of claims 1 to 3. The resist composition according to any one of claims 1 to 4, wherein the (B) is an acid generator composed of a salt represented by the following 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 aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. .
Y represents a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and the methylene group constituting the monovalent aliphatic hydrocarbon group includes an oxygen atom, a sulfonyl group Alternatively, it may be replaced with a carbonyl group.
Z ⁺ represents an organic sulfonium cation or an organic iodonium cation. ] The resist composition according to claim 5, wherein L ^{b1 in the} formula (B1) is a group represented by the following formula (b1-1).

[In the formula (b1-1),
L ^b2 represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
Two * 's represent a bond, the left * is a bond with a carbon atom of C (Q ¹ ) (Q ² ), and the right * is a bond with Y. ]   The resist composition according to claim 5 or 6, 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 Claims 1-7 on a board | substrate;
(2) The process of drying the composition after application | coating and forming a composition layer;
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating. Use of the salt represented by the formula (I) as an additive for a resist composition.

[In the formula (I),
L ¹ and L ² each independently represent an alkanediyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkanediyl group is an oxygen atom, —NR ⁵ — (R ⁵ is a hydrogen atom or carbon Represents an alkyl group of 1 to 6) or a carbonyl group, and a hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a hydroxy group.
R ² and R ³ each independently represent an alkyl group having 1 to 6 carbon atoms.
R ⁴ represents SO ₃ ⁻ , CO ₂ ^— or O ⁻ .
W is the formula (W-I)

(In the formula (W-I),
n represents an integer of 0 to 6.
R ¹ represents a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and a methylene group constituting the monovalent aliphatic hydrocarbon group. May be replaced by an oxygen atom or a carbonyl group.
When n is 2 or more, all or a part of the plurality of R ¹ may be the same.
The methylene group constituting the ring may be replaced with an oxygen atom or a carbonyl group.
The dotted line represents that the bond including the dotted line may be a single bond or a double bond.
m represents an integer of 1 to 5.
* Is a bond to ^{L 1.} )
It is group represented by these. ]