JP2012219164A - Method for producing resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a resin for resist compositions capable of giving excellent line width roughness.SOLUTION: The method for producing the resin having structural units represented by formulas (I) and (II) includes the first step of polymerizing a monomer represented by formula (III) and a monomer represented by formula (IV), and the second step of hydrolyzing the product obtained in the first step to convert -O-CO-Rinto -OH, wherein Rand Rare each alkyl, a hydrogen atom or a halogen atom; R-Rare each alkyl or an alicyclic hydrocarbon group; Rand Rare bound to each other to form a divalent hydrocarbon group; Xand Xare each a single bond or a divalent linking group; Rand Rare each alkyl, or are bound to each other to form a divalent hydrocarbon group.

Description

  The present invention relates to a method for producing a resin.

In Patent Document 1, 1-ethylcyclopentyl methacrylate and p- (1-ethoxyethoxy) styrene are added to a solvent to polymerize them, and the resulting product p- (1-ethoxyethoxy) is obtained. ) By having —OH—CH (CH ₃ ) —O—CH ₂ CH ₃ of a structural unit derived from styrene as —OH, it has a structural unit derived from 1-ethylcyclopentyl methacrylate and p-hydroxystyrene, respectively. A method for producing a resin to obtain a resin is described.

JP 2002-234910 A

  In a resist composition containing a resin obtained by a conventional method for producing a resin, the line width roughness (LWR) of a resist pattern obtained from the resist composition may not be sufficiently satisfactory.

［式（Ｉ）〜式（ＩＶ）中、
Ｒ^１及びＲ^５は、それぞれ独立に、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^２、Ｒ^３及びＲ^４は、それぞれ独立に、炭素数１〜６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^２及びＲ^３は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。
Ｒ^６は、炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基を表す。
Ｘ^１及びＸ^２は、それぞれ独立に、単結合又は炭素数１〜２０の２価の炭化水素基を表し、該炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＣＯ−又は−ＮＨ−で置き換わっていてもよい。
Ｒ^７及びＲ^８は、それぞれ独立に、炭素数１〜１０のアルキル基を表すか、互いに結合して２価の炭化水素基を形成する。
ｓは、１又は２の整数を表す。
ｔは、０〜２の整数を表す。］ The present invention includes the following inventions.
[1] A method for producing a resin having a structural unit represented by formula (I) and a structural unit represented by formula (II),
The monomer solution represented by formula (IV) is added to the monomer solution represented by formula (III) to polymerize the monomer represented by formula (III) and the monomer represented by formula (IV). A first step of
A second step in which —O—CHR ⁸ —O—R ⁷ of the product obtained in the first step is changed to —OH;
The manufacturing method of resin which has this.

[In Formula (I)-Formula (IV),
R ¹ and R ⁵ each independently represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
R ² , R ³ and R ⁴ each independently represents an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ² and R ³ are bonded to each other to form carbon. A divalent hydrocarbon group of 2 to 20 is formed.
R ⁶ represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.
X ¹ and X ² each independently represent a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —CO— or It may be replaced by —NH—.
R ⁷ and R ⁸ each independently represent an alkyl group having 1 to 10 carbon atoms or are bonded to each other to form a divalent hydrocarbon group.
s represents an integer of 1 or 2.
t represents an integer of 0-2. ]

[2] The method for producing a resin according to [1], wherein the second step is a step of hydrolyzing the product obtained in the first step to convert —O—CHR ⁸ —O—R ⁷ to —OH. .

［式（ａ１−１）中、
Ｌ^a1は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^a4は、水素原子又はメチル基を表す。
Ｒ^a6は、炭素数１〜６のアルキル基又は炭素数３〜１０の脂環式炭化水素基を表す。
ｍ１は０〜１４の整数を表す。］ [3] The method for producing a resin according to [1] or [2], wherein the monomer represented by the formula (III) is a monomer represented by the formula (a1-1).

[In the formula (a1-1),
L ^a1 represents —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—.
R ^a4 represents a hydrogen atom or a methyl group.
R ^a6 represents an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14. ]

[4] X ¹ represents a single bond or —CO—O—X ³ — ^* [ ^* represents a bond with —CO—, and X ³ represents an alkylene group having 1 to 6 carbon atoms. ] The manufacturing method of resin in any one of [1]-[3].

[5] The method for producing a resin according to any one of [1] to [4], wherein X ² is a single bond.

[6] A resist composition containing a resin obtained by the method for producing a resin according to any one of [1] to [5] and an acid generator.

[7] (1) A step of applying the resist composition according to [6] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure,
(5) A method for producing a resist pattern including a step of developing the composition layer after heating.

  A pattern having excellent line width roughness (LWR) can be obtained from a resist composition containing a resin obtained by the method for producing a resin of the present invention.

  The present invention is a method for producing a resin having a structural unit represented by formula (I) and a structural unit represented by formula (II), and includes a first step and a second step described below. It is a manufacturing method of resin. Hereinafter, the resin obtained by the production method of the present invention may be referred to as “resin (A)”. Resin (A) is suitable as a resin for the resist composition.

［式（Ｉ）中、
Ｒ^１は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^２、Ｒ^３及びＲ^４は、それぞれ独立に、炭素数１〜６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^２及びＲ^３は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。
Ｘ^１は、単結合又は炭素数１〜２０の２価の炭化水素基を表し、該炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＣＯ−又は−ＮＨ−で置き換わっていてもよい。］ (Structural unit represented by formula (I))
The structural unit represented by the formula (I) is a structural unit derived from a monomer represented by the formula (III) described later.

[In the formula (I),
R ¹ represents a C 1-6 alkyl group, a hydrogen atom or a halogen atom which may have a halogen atom.
R ² , R ³ and R ⁴ each independently represents an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ² and R ³ are bonded to each other to form carbon. A divalent hydrocarbon group of 2 to 20 is formed.
X ¹ represents a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is replaced by —O—, —CO— or —NH—. Also good. ]

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. It is a C1-C4 alkyl group, More preferably, it is a C1-C2 alkyl group, Especially preferably, it is a methyl group.
Examples of the alkyl group having a halogen atom include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. It is done.
Examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom.

The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and dimethylcyclohexane. Examples thereof include a cycloalkyl group such as a hexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic saturated hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups. The carbon number of the alicyclic hydrocarbon group is preferably 3 to 16 carbon atoms.

When R ² and R ³ are bonded to each other to form a divalent hydrocarbon group, examples of the —C (R ² ) (R ³ ) (R ⁴ ) group include the following groups. The carbon number of the divalent hydrocarbon group is preferably 3 to 12 carbon atoms.

X ¹ represents a single bond, —CO—O—X ³ — ^* [ ^* represents a bond to —CO—, and X ³ represents an alkylene group having 1 to 6 carbon atoms. ] Etc. are mentioned.
X ² includes a single bond, —CO—O— ^* , —CO—NH— ^* , —CO—O—X ⁴ —CO—O— ^* , —CO—O—X ⁴ —O— ^* , —CO —O—X ⁴ —NH—CO—O— ^* , [ ^* represents a bond with a phenyl group, and X ⁴ represents an alkylene group having 1 to 6 carbon atoms. A single bond or —CO—O— ^* is preferable.

  Among the structural units represented by the formula (I), those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If a resin having a structural unit having a bulky structure such as an alicyclic hydrocarbon group is used, the resolution of the resist can be improved.

  As a structural unit represented by Formula (I), the following structural unit is mentioned, for example.

  The content of the structural unit represented by the formula (I) in the resin (A) is usually 10 to 95 mol%, preferably 15 to 90 mol%, and more preferably 20 to 20 mol% in all units of the resin. 85 mol%.

［式（ＩＩ）中、
Ｒ^５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^６は、炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基を表す。
Ｘ^２は、単結合又は炭素数１〜２０の２価の炭化水素基を表し、該炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＣＯ−又は−ＮＨ−で置き換わっていてもよい。
ｓは、１又は２の整数を表す。
ｔは、０〜２の整数を表す。］ (Structural unit represented by formula (II))

[In the formula (II),
R ⁵ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
R ⁶ represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.
X ² represents a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is replaced by —O—, —CO— or —NH—. Also good.
s represents an integer of 1 or 2.
t represents an integer of 0-2. ]

  Examples of the alkyl group, the alkyl group having a halogen atom, and the halogen atom include the same groups as described above.

Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, and an n-hexoxy group. Is an alkoxy group having 1 to 4 carbon atoms, more preferably an alkoxy group having 1 or 2 carbon atoms, and particularly preferably a methoxy group.
s is preferably 1.
t is preferably 0 or 1, particularly preferably 0.

  Examples of the structural unit represented by the formula (II) include the following structural units. Preferably, a structural unit derived from 4-hydroxystyrene or a structural unit derived from 4-hydroxy-α-methylstyrene is used. Can be mentioned.

  The content of the structural unit represented by the formula (II) in the resin (A) is usually 10 to 95 mol%, preferably 15 to 90 mol%, and more preferably 20 to 20 mol% in all the units of the resin. 85 mol%.

<First step>
In the first step, the monomer solution represented by the formula (IV) is added to the monomer solution represented by the formula (III), and the monomer represented by the formula (III) and the formula (IV) are represented. The monomer to be polymerized is polymerized. This polymerization is preferably performed using a polymerization initiator. The monomer represented by the formula (III) and the monomer represented by the formula (IV) may be collectively referred to as “monomer” hereinafter.

  As the first step, a method of dissolving the whole amount of the monomer represented by the formula (III) used in the first step in a solvent (hereinafter sometimes referred to as “first step A”) and a first step. And a method of dissolving a part of the monomer represented by formula (III) used in one step in a solvent (hereinafter sometimes referred to as “first step B”).

(First step A)
The monomer represented by formula (III) (the total amount of monomers represented by formula (III) used in the first step) is dissolved in a solvent, charged into a reaction vessel, and maintained at a predetermined reaction temperature. Separately, a solution in which the monomer represented by the formula (IV) is dissolved in a solvent is prepared, and this is charged into the reaction vessel over a certain period of time. A polymerization initiator is also charged into the reaction vessel over a certain period of time. At this time, the polymerization initiator may be mixed with the monomer solution represented by the formula (IV) or may be charged by a different route from the monomer solution represented by the formula (IV). Good. The polymerization reaction is started by adding the polymerization initiator. After completion of the addition, the resin is obtained by holding at the predetermined reaction temperature for several hours.

(First step B)
A part of the monomer represented by the formula (III) (part of the monomer represented by the formula (III) used in the polymerization reaction) is dissolved in a solvent and charged into a reaction vessel, and the reaction temperature reaches a predetermined reaction temperature. Hold. Separately, the remainder of the monomer represented by the formula (III) and the monomer represented by the formula (IV) are prepared in the form of a solution dissolved in a solvent, and this is charged into the reaction vessel over a certain period of time. To do. At this time, the remainder of the monomer represented by the formula (III) and the monomer represented by the formula (IV) may be mixed to form a solution, or separately. A polymerization initiator is also charged into the reaction vessel over a certain period of time. At this time, the polymerization initiator may be mixed with the remainder of the monomer represented by the formula (III) and the monomer represented by the formula (IV), or may be added to the monomer represented by the formula (III). The remainder and the monomer represented by formula (IV) may be added through a different route. The polymerization reaction is started by adding the polymerization initiator. After completion of the addition, the desired resin is obtained by holding at the predetermined reaction temperature for several hours.

  The total amount of monomers used in the production method of the present invention (that is, the total amount of the monomer represented by formula (III) and the monomer represented by formula (IV)) is represented by formula (III). The proportion of the total amount of monomers is preferably 5 to 70% by weight, more preferably 20 to 40% by weight. In this range, a resist film with fewer defects can be provided. From the same viewpoint, the proportion of the monomer represented by the formula (III) initially charged in the reaction vessel is 3 to 40% by weight of the total amount of the monomer represented by the formula (III). preferable.

  Although various polymerization methods can be used in the polymerization in the first step, it is preferable to use a radical polymerization method.

In the radical polymerization method, an organic solvent is preferably used. As this organic solvent, it is a solvent which can melt | dissolve normally all of a monomer, a polymerization initiator, and the copolymer obtained.
Examples of such organic solvents include hydrocarbons such as toluene, 1,4-dioxane, tetrahydrofuran, methyl isobutyl ketone, isopropyl alcohol, γ-butyrolactone, propylene glycol monomethyl ether acetate, ethyl lactate, and the like. Dioxane is preferred. These solvents may be used alone or in combination of two or more.

  The reaction temperature in the radical polymerization method is usually in the range of 0 to 150 ° C, preferably in the range of 40 to 100 ° C. The reaction temperature is adjusted according to the type of polymerization initiator used. The amount of the organic solvent used is preferably 1 to 5 times the weight of the total amount of charged monomers, and the amount of the polymerization initiator used is preferably 1 to 20 mol% with respect to the total amount of charged monomers.

［式（ＩＩＩ）中、
Ｒ^１は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^２、Ｒ^３及びＲ^４は、それぞれ独立に、炭素数１〜６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^２及びＲ^３は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。
Ｘ^１は、単結合又は炭素数１〜２０の２価の炭化水素基を表し、該炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＣＯ−又は−ＮＨ−で置き換わっていてもよい。］ (Monomer represented by formula (III))

[In the formula (III),
R ¹ represents a C 1-6 alkyl group, a hydrogen atom or a halogen atom which may have a halogen atom.
R ² , R ³ and R ⁴ each independently represents an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ² and R ³ are bonded to each other to form carbon. A divalent hydrocarbon group of 2 to 20 is formed.
X ¹ represents a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is replaced by —O—, —CO— or —NH—. Also good. ]

The monomer represented by the formula (III) is a monomer that gives the structural unit represented by the formula (I).
The monomer represented by the formula (III) is preferably a monomer represented by the formula (a1-1) or a monomer represented by the formula (a1-2). These may be used alone or in combination of two or more.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜６のアルキル基又は炭素数３〜１０の脂環式炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ２は０又は１の整数を表す。］

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n2 represents an integer of 0 or 1. ]

L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, more preferably —O—. k1 is preferably an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group and the alicyclic hydrocarbon group for R ^a6 and R ^a7 include the same groups as described above, preferably a methyl group or an ethyl group.
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.

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 (a1-1-6) are preferred, and monomers represented by the following formulas (a1-1-1) to (a1-1-3) are more preferred. .

Examples of the monomer represented by the formula (a1-2) include 1-ethyl-1-cyclopentyl (meth) acrylate, 1-ethyl-1-cyclohexyl (meth) acrylate, 1-ethyl-1-cycloheptyl (meta ) Acrylate, 1-methyl-1-cyclopentyl (meth) acrylate, 1-isopropyl-1-cyclopentyl (meth) acrylate, and the like. Monomers represented by the following formulas (a1-2-1) to (a1-2-6) are preferred, and monomers represented by the following formulas (a1-2-3) to (a1-2-4) are more preferred. A monomer represented by the following formula (a1-2-3) is more preferable.

［式（ＩＶ）中、
Ｒ^５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^６は、炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基を表す。
Ｘ^２は、単結合又は炭素数１〜２０の２価の炭化水素基を表し、該炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＣＯ−又は−ＮＨ−で置き換わっていてもよい。
Ｒ^７及びＲ^８は、それぞれ独立に、炭素数１〜１０のアルキル基を表すか、互いに結合して２価の炭化水素基を形成する。
ｓは、１又は２の整数を表す。
ｔは、０〜２の整数を表す。］ (Monomer represented by the formula (IV))

[In the formula (IV),
R ⁵ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
R ⁶ represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.
X ² represents a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is replaced by —O—, —CO— or —NH—. Also good.
R ⁷ and R ⁸ each independently represent an alkyl group having 1 to 10 carbon atoms or are bonded to each other to form a divalent hydrocarbon group.
s represents an integer of 1 or 2.
t represents an integer of 0-2. ]

Examples of the alkyl group include the same groups as described above.
Examples of the divalent hydrocarbon group include an alkylene group having 1 to 6 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, Linear alkylene groups such as butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group;
On the side of an alkyl group (particularly an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group) Having a chain, for example, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene Group, branched alkylene such as 2-methyl-1,4-butylene group;
Etc.
When R ⁷ and R ⁸ are bonded to each other to form a divalent hydrocarbon group, the ring formed together with R ⁷ and R ⁸ —CH—O— preferably has a 3 to 7-membered ring structure. Examples include 2-furanyloxy group and 2-pyranyloxy group.

Examples of the monomer represented by the formula (IV) include the following monomers, preferably ethoxyethoxystyrene, and more preferably p-ethoxyethoxystyrene.

(Polymerization initiator)
A known compound can be used as the polymerization initiator. Specifically, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2 , 2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2′-azobis (2-methylpropionate) ), 2,2′-azobis (2-hydroxymethylpropionitrile) and the like; lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide, Diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, tert-butyl peroxy Organic peroxides such as cineodecanoate, tert-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide; inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide Can be mentioned.

  Of these, azo compounds are preferred, and 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile). ), 1,1′-azobis (cyclohexane-1-carbonitrile) and dimethyl-2,2′-azobis (2-methylpropionate), more preferably 2,2′-azobisisobutyronitrile, 2 2,2′-azobis (2,4-dimethylvaleronitrile) is more preferred. When two kinds of polymerization initiators are used in combination, 2,2′-azobis (2,4-dimethylvaleronitrile) and 2,2′-azobisisobutyronitrile are combined, 2,2′-azobis ( 2,2-dimethylvaleronitrile) and 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile) and 1,1′-azobis ( A combination with cyclohexane-1-carbonitrile), and a combination of 2,2′-azobis (2,4-dimethylvaleronitrile) and dimethyl-2,2′-azobis (2-methylpropionate), The molar ratio is preferably in the range of 1: 1 to 1:10.

<Second step>
In the second step, —O—CHR ⁸ —O—R ⁷ of the product obtained in the first step is changed to —OH. A resin (A) can be manufactured through a 2nd process after a 1st process.
Of ^{-O-CHR 8 -O-R 7} , the proportion of radicals consisting -OH, relative to the total amount of the ^{-O-CHR 8 -O-R 7} , for example 80% to 100%, preferably from 90 to 100%.

It is preferable to hydrolyze the product obtained in the first step to change —O—CHR ⁸ —O—R ⁷ to —OH. Hydrolysis means that a solute reacts with water and decomposes.
As a method for converting —O—CHR ⁸ —O—R ⁷ to —OH, for example, T.W. W. TW Greene and P.I. G. M.M. By PGMWuts, "Protective Groups in Organic Synthesis", 4th edition, John Wiley & Sons, New York, 2007 and references cited therein. be able to.

As the hydrolysis, a resin having a structural unit represented by formula (I) and a structural unit represented by formula (II) can be obtained by deprotecting an acetal protecting group in an organic solvent. As a catalyst at the time of hydrolysis, oxalic acid, acetic acid, p-toluenesulfonic acid, sulfuric acid, hydrochloric acid and the like can be used. The reaction temperature is 20 to 50 ° C., and the reaction time is 0.2 to 100 hours, preferably 0.5 to 20 hours.
After hydrolysis, the acid can be neutralized according to a conventional method, followed by crystallization using a poor solvent, and a resin can be obtained through filtration and drying steps. Or it can obtain as a resin solution by substituting with arbitrary solvents after neutralization. As an arbitrary solvent, the solvent for resist compositions is mentioned, for example. Moreover, you may filter a solution in the middle of the said process.

<Structural units derived from other monomers>
The resin (A) may have a structural unit derived from other known monomers other than the above monomers.

Specific examples of the resin (A) are shown by combinations of structural units derived from the formula (I), structural units derived from the formula (II), and structural units derived from other monomers.

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

The resist composition of the present invention contains a resin (A) and an acid generator.
The content of the resin in the resist composition is preferably 80% by mass or more in the solid content of the composition.
In the present specification, the “solid content in the composition” means the total of resist composition components excluding the solvent (E) described later. The solid content in the composition and the content of the resin (A) relative thereto can be measured, for example, by a known analysis means such as liquid chromatography or gas chromatography.

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

  Examples of the acid generator (B) include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712. The compound which generate | occur | produces an acid by the radiation as described in No. can be used.

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a sulfonate represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”). .

［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２価の炭素数１〜１７の飽和炭化水素基を表し、前記２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で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、前記アルキル基及び前記脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］

[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 a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. May be.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the alkyl group and the above —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. It is done.
In formula (B1), Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group include a linear alkylene group, a branched alkylene group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a combination of two or more of these groups. It may be a thing.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkylene groups such as 17-diyl group, methylidene group, ethylidene group, propylidene group, 2-propylidene group;
On the side of an alkyl group (particularly an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group) Having a chain, for example, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene Group, branched alkylene such as 2-methyl-1,4-butylene group;
Monocyclic alicyclic hydrocarbon groups which are cycloalkylene groups such as 1,3-cyclobutylene group, 1,3-cyclopentylene group, 1,4-cyclohexylene group, 1,5-cyclooctylene group ;
Examples thereof include polycyclic alicyclic hydrocarbon groups such as 1,4-norbornylene group, 2,5-norbornylene group, 1,5-adamantylene group, 2,6-adamantylene group and the like.

Examples of the group in which —CH ₂ — contained in the saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include formula (b1-1) to formula (b1-6). L ^b1 is preferably any one of formulas (b1-1) to (b1-4), more preferably formula (b1-1) or formula (b1-2). Incidentally, the formula (b1-1) ~ formula (b1-6) are described together the left and right in the equation (B1), the left ^{C (Q 1) (Q 2} ) - bound to, the right side Combines with -Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又は炭素数１〜１５の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の飽和炭化水素基を表す。但しＬ^b3及びＬ^b4の炭素数上限は１３である。
Ｌ^b5は、炭素数１〜１５の飽和炭化水素基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の飽和炭化水素基を表す。但しＬ^b6及びＬ^b7の炭素数上限は１６である。
Ｌ^b8は、炭素数１〜１４の飽和炭化水素基を表す。
Ｌ^b9及びＬ^b10は、それぞれ独立に、炭素数１〜１１の飽和炭化水素基を表す。但しＬ^ｂ９及びＬ^ｂ１０の炭素数上限は１２である。
中でも、好ましくは式（ｂ１−１）で表される２価の基であり、より好ましくは、Ｌ^b2が単結合又は−ＣＨ_２−である式（ｂ１−１）で表される２価の基である。

In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or a saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 and L ^b7 each independently represent a saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 and L ^b10 each independently represent a saturated hydrocarbon group having 1 to 11 carbon atoms. However, the upper limit of the carbon number of L ^b9 and L ^b10 is 12.
Among them, a divalent group represented by the formula (b1-1) is preferable, and a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or —CH ₂ — is more preferable. It is a group.

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 an alkyl group of Y, Preferably, a C1-C6 alkyl group is mentioned.
Examples of the substituent for the alkyl group and the alicyclic hydrocarbon group include a halogen atom, a hydroxy group, an oxo group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and 3 carbon atoms. -16 alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C4 acyl group, glycidyl An oxy group or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or 6 carbon atoms) Represents an aromatic hydrocarbon group of ˜18.j2 represents an integer of 0 to 4.) and the like. The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group, and the like, which are substituents for Y, may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.
Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the group in which —CH ₂ — in the alkyl group and alicyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— include, for example, a cyclic ether group (—CH ₂ — is —O—). ), An alicyclic hydrocarbon group having an oxo group (a group in which —CH ₂ — is replaced by —CO—), and a sultone ring group (two adjacent —CH ₂ — are each represented by —O— Or a group substituted by —SO ₂ —) or a lactone ring group (a group in which two adjacent —CH ₂ — are each replaced by —O— or —CO—).

In particular, examples of the alicyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y26).

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

  Y is preferably an adamantyl group which may have a substituent (for example, an oxo group or the like), more preferably an adamantyl group or an oxoadamantyl group.

The sulfonate anion in the salt represented by the formula (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-1-9). In the following formulae, the definition of the substituent has the same meaning as described above, and the substituents R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include the anions described in JP 2010-204646 A.

  The cation contained in the acid generator (B) includes an onium cation such as a sulfonium cation, an iodonium cation, an ammonium cation, a benzothiazolium cation, and a phosphonium cation, and preferably a sulfonium cation or an iodonium cation. More preferred is an arylsulfonium cation.

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

In these formulas (b2-1) to (b2-4),
R ^{b4 to} R ^b6 each independently represents an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The alkyl group may be substituted with 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 has a halogen atom or a carbon number. The aromatic hydrocarbon group may be substituted with an acyl group of 2 to 4 or a glycidyloxy group, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms, or an alicyclic group having 3 to 18 carbon atoms. It may be substituted with a hydrocarbon group or an alkoxy group having 1 to 12 carbon atoms.

R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.

R ^b9 and R ^b10 each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The alkyl group of R ^{b9 to} R ^b11 preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.
R ^b12 represents an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkylcarbonyloxy group having 1 to 12 carbon atoms. May be substituted.
R ^b9 and R ^b10 , and R ^b11 and R ^b12 may be independently bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring), These rings —CH ₂ — may be replaced by —O—, —S— or —CO—.

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 -S- or -O-.
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 any of o2 to t2 is 2, any of the plurality of R ^{b13 to} R ^b18 may be the same as or different from each other.

  Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

The alkyl group is preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Is mentioned.
The alicyclic hydrocarbon group is preferably a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclodecyl group, a 2-alkyl-2-adamantyl group, or 1- (1-adamantyl) -1 -An alkyl group and an isobornyl group are mentioned.
The aromatic hydrocarbon group is preferably a phenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-cyclohexylphenyl group, a 4-methoxyphenyl group, or a biphenylyl group. And a naphthyl group.
Examples of the alkyl group (aralkyl group) whose substituent is an aromatic hydrocarbon group include a benzyl group.
Examples of the ring formed by R ^b9 and R ^b10 include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
^Examples of the ring formed by R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, and the cation represented by the formula (b2-1-1) is more preferable. Is a triphenylsulfonium cation (v2 = w2 = x2 = 0 in formula (b2-1-1)).

式（ｂ２−１−１）中、
Ｒ^b19〜Ｒ^b21は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、炭素数１〜１８のアルキル基、炭素数３〜１８の脂環式炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
アルキル基は、好ましくは炭素数１〜１２であり、脂環式炭化水素基は、好ましくは炭素数４〜１８である。
前記アルキル基は、ヒドロキシ基、炭素数１〜１２のアルコキシ基又は炭素数６〜１８の芳香族炭化水素基で置換されていてもよい。
前記脂環式炭化水素基は、ハロゲン原子、炭素数２〜４のアシル基又はグリシジルオキシ基で置換されていてもよい。
ｖ２〜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〜ｘ２のいずれかが２以上のとき、それぞれ、複数のＲ^b19〜Ｒ^b21のいずれかは、互いに同一でも異なってもよい。
なかでも、Ｒ^b19〜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。

In formula (b2-1-1),
R ^{b19 to} R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 1 to 1 carbon atoms. 12 alkoxy groups are represented.
The alkyl group preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
The alkyl group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The alicyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group.
v2 to x2 each independently represents an integer of 0 to 5 (preferably 0 or 1). When any one of v2 to x2 is 2 or more, any one of the plurality of R ^{b19 to} R ^b21 may be the same as or different from each other.
Among them, R ^{b19 to} R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. .

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

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

  The acid generator (B1) is preferably a salt represented by the formula (B1-1) to the formula (B1-17), and more preferably an acid generator (B1-) containing a triphenylsulfonium cation. 1), (B1-2), (B1-6), (B1-11), (B1-12), (B1-13) and (B1-14).

  The content of the acid generator (B) in the resin (A) is preferably 1% by mass or more (more preferably 3% by mass or more), preferably 30% by mass or less (more preferably 25% by mass or less). .

<Quencher (hereinafter sometimes referred to as “quencher (C)”)>
The resist composition of the present invention preferably contains a quencher (C).

  The quencher (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The quencher (C) is preferably a compound represented by the formula (C1) to a compound represented by the formula (C9), more preferably a compound represented by the formula (C1-1) and the formula ( And compounds represented by C9).

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

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

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

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

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

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

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

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

Wherein (C7) and formula ^{(C8), R c18, R} c19 and R ^c20 in each occurrence independently represent the same meaning as R ^c4.
q3, r3 and s3 each independently represent an integer of 0 to 3, q3, when r3 and s3 is 2 or more, each of a plurality of R ^c18, R ^c19 and R ^{c 20} may be the same or different from each other .
L ^c2 represents a single bond or an alkylene group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

［式（Ｃ９）中、Ｒ^c21、Ｒ^c2２、Ｒ^c2３及びＲ^c2４は、それぞれ独立に、置換基を有していてもよい炭素数１〜２０のアルキル基、置換基を有していてもよい炭素数３〜２０の飽和環状炭化水素基又は置換基を有していてもよい炭素数２〜２０のアルケニル基を表す。
Ｒ^c25は、置換基を有していてもよいＣ₁〜Ｃ₃₆炭化水素基を表し、該炭化水素基はヘテロ原子を含んでいてもよい。］

[In the formula (C9), R ^c21 , R ^{c2 2} , R ^c23 and R ^c24 may each independently have a C 1-20 alkyl group which may have a substituent or a substituent. The C3-C20 saturated cyclic hydrocarbon group or the C2-C20 alkenyl group which may have a substituent is represented.
R ^c25 represents a C ₁ -C ₃₆ hydrocarbon group which may have a substituent, and the hydrocarbon group may contain a hetero atom. ]

  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-diphenyl Examples include ethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl Ruanirin. Particularly preferred include 2,6-diisopropylaniline.

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

Examples of the cation contained in the compound represented by the formula (C9) include cations represented by the formulas (IA-1) to (IA-8).

Examples of the anion contained in the compound represented by formula (C9) include cations represented by formula (IB-1) to formula (IB-16).

  Examples of the compound represented by formula (C9) include compounds represented by formula (C9-1) to formula (C9-55), which are represented by formula (C9-1) to formula (C9-5). And compounds represented by formula (C9-12) to formula (C9-30) are preferred, and compounds represented by formula (C9-12) to formula (C9-21) are more preferred.

  As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

  The content of the quencher (C) is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably 0, based on the solid content of the resist composition. About 0.01 to 1% by mass.

<Solvent (sometimes referred to as "solvent (E)")
The resist composition of the present invention may contain a solvent (E). The content of the solvent (E) is, for example, 90% by mass or more in the resist composition, preferably 92% by mass or more, more preferably 94% by mass or more, for example 99.9% by mass or less, preferably 99% by mass or less. It is.
The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

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

<Other components (hereinafter sometimes referred to as “other components (F)”)>
The resist composition of this invention may contain the other component (F) as needed. The component (F) is not particularly limited, and additives known in the resist field, for example, sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like can be used.

<This resist composition and its preparation method>
This resist composition is obtained by mixing the resin (A), the acid generator (B) and the solvent (E), or
It can be prepared by mixing the resin (A), the acid generator (B), the quencher (C), and the solvent (E). In such mixing, the mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature range from the range of 10-40 degreeC according to the kind etc. of resin, the solubility with respect to solvent (E), such as resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.

  As described above, after mixing the resin (A), the acid generator (B) and the solvent (E), and each of the quencher (C) or the component (F) used as necessary, at a preferable content, The present resist composition can be prepared by filtration using a filter having a pore size of about 0.2 μm.

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

  Application of the resist composition onto the substrate can be performed by a commonly used apparatus such as a spin coater.

The composition after application is dried to remove the solvent. The removal of the solvent is performed, for example, by evaporating the solvent using a heating device such as a hot plate or by using a decompression device to form a composition layer from which the solvent has been removed. As for the temperature in this case, about 50-200 degreeC is illustrated, for example. The pressure is exemplified by about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. The exposure light source emits ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser, etc.) Various types of laser beam can be used, such as those that convert the wavelength of the laser beam from) to radiate a harmonic laser beam in the far ultraviolet region or the vacuum ultraviolet region.

The composition layer after the exposure is subjected to heat treatment for promoting the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The heated composition layer is usually developed using an alkali developer using a developing device.
The alkaline developer used here may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).
After development, it is preferable to rinse with ultrapure water to remove water remaining on the substrate and the pattern.

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

Hereinafter, the present invention will be described in detail by way of examples.
In Examples and Comparative Examples, “%” and “part” representing content and use amount 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 under the following conditions.
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)

Example 1: Synthesis of Resin A1 In a four-necked flask equipped with a condenser and a stirrer, 19.99 parts of 1,4-dioxane and 3.49 parts of 2-ethyl-2-adamantyl methacrylate were charged, and after replacement with nitrogen 82 The temperature was raised to ° C. Thereto, p- (1-ethoxyethoxy) styrene 18.00 parts, 2-ethyl-2-adamantyl methacrylate 8.14 parts, 3.hydroxy-1-adamantyl methacrylate 3.69 parts and azobisisobutyronitrile A solution prepared by dissolving 2.05 parts in 29.98 parts of 1,4-dioxane was added dropwise over 1 hour. Thereafter, stirring was continued for 6 hours while maintaining 82 ° C. The obtained reaction solution was poured into a cooled mixed solution of 303 parts of methanol and 130 parts of ion-exchanged water to reprecipitate the resin. The resin obtained after filtration was dissolved in 100 parts of methyl isobutyl ketone, a solution prepared by dissolving 0.67 parts of p-toluenesulfonic acid in 66.63 parts of ion-exchanged water was added and stirred for 6 hours, and p- (1-ethoxy The structural unit —O—CH (CH ₃ ) —O—CH ₂ CH ₃ derived from ethoxy) styrene was hydrolyzed to —OH. After separation, the organic layer was washed 3 times with 67 parts of ion exchange water, 67 parts of methyl isobutyl ketone was added, and the mixture was concentrated to 134 parts. This solution was poured into 433 parts of n-heptane to precipitate a resin. The precipitated resin was collected by filtration and dried under reduced pressure to obtain 25.20 parts of a copolymer having a weight average molecular weight of about 5.06 × 10 ³ . This is designated as resin A1.

Comparative Example 1: Synthesis of Resin H1 19.21 parts of 1,4-dioxane was charged into a four-necked flask equipped with a condenser and a stirrer, and the temperature was raised to 82 ° C. after substitution with nitrogen. Thereto, 17.30 parts of p- (1-ethoxyethoxy) styrene, 11.17 parts of 2-ethyl-2-adamantyl methacrylate, 3.54 parts of 3-hydroxy-1-adamantyl methacrylate and azobisisobutyronitrile A solution prepared by dissolving 1.97 parts in 28.82 parts of 1,4-dioxane was added dropwise over 1 hour. Thereafter, stirring was continued for 6 hours while maintaining 82 ° C. The obtained reaction solution was poured into a cooled mixed solution of 291 parts of methanol and 125 parts of ion-exchanged water to reprecipitate the resin. The resin obtained after filtration was dissolved in 96 parts of methyl isobutyl ketone, and a solution prepared by dissolving 0.64 part of p-toluenesulfonic acid in 64 parts of ion-exchanged water was added and stirred for 6 hours. After separation, the organic layer was washed 3 times with 64 parts of ion exchange water, 64 parts of methyl isobutyl ketone was added, and the mixture was concentrated to 128 parts. This solution was poured into 416 parts of n-heptane to precipitate a resin. The precipitated resin was collected by filtration and dried under reduced pressure to obtain 24.20 parts of a copolymer having a weight average molecular weight of about 5.10 × 10 ³ . This is designated as resin H1.

  The components in the following table were mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
Resin A1
Resin H1

<Acid generator>
Acid generator B1

<Quencher>
Compound C1:

<Solvent>
Solvent E1:
Propylene glycol monomethyl ether acetate 430.0 parts Propylene glycol monomethyl ether 150.0 parts γ-butyrolactone 5.0 parts

Evaluation as a resist composition for an electron beam A silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 110 ° C. for 60 seconds, and the film thickness after drying the resist composition was 0.05 μm. It spin-coated so that it might become. After applying the resist composition, it was pre-baked (PB) for 60 seconds at a temperature shown in Table 3 on a direct hot plate. An electron beam lithography machine [“HL-800D” manufactured by Hitachi, Ltd. was applied to each wafer on which the resist film was formed.
The line-and-space pattern was exposed by changing the exposure amount stepwise using “50 keV”. After the exposure, post-exposure baking (PEB) was performed for 60 seconds at a temperature shown in Table 3 on a hot plate, and paddle development was further performed for 60 seconds with a 2.38 wt% tetramethylammonium hydroxide aqueous solution.

  LWR (line width roughness) evaluation: In each resist film, a 0.1 μm line-and-space pattern of 1: 1 was measured using SuMMIT software (EUV Technology), and the width of the pattern was measured. Samples with a tack of less than 9 nm were marked with ◯ and those with a thickness of 9 nm or more were marked with ×. The smaller the value, the smaller the width of the pattern and the better the performance.

  A pattern having excellent line width roughness (LWR) can be obtained from a resist composition containing a resin obtained by the method for producing a resin of the present invention.

Claims (7)

A method for producing a resin having a structural unit represented by formula (I) and a structural unit represented by formula (II),
The monomer solution represented by formula (IV) is added to the monomer solution represented by formula (III) to polymerize the monomer represented by formula (III) and the monomer represented by formula (IV). A first step of
A second step in which —O—CHR ⁸ —O—R ⁷ of the product obtained in the first step is changed to —OH;
The manufacturing method of resin which has this.

[In Formula (I)-Formula (IV),
R ¹ and R ⁵ each independently represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
R ² , R ³ and R ⁴ each independently represents an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ² and R ³ are bonded to each other to form carbon. A divalent hydrocarbon group of 2 to 20 is formed.
R ⁶ represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.
X ¹ and X ² each independently represent a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —CO— or It may be replaced by —NH—.
R ⁷ and R ⁸ each independently represent an alkyl group having 1 to 10 carbon atoms or are bonded to each other to form a divalent hydrocarbon group.
s represents an integer of 1 or 2.
t represents an integer of 0-2. ] The method for producing a resin according to claim 1, wherein the second step is a step of hydrolyzing the product obtained in the first step to change —O—CHR ⁸ —O—R ⁷ to —OH. The method for producing a resin according to claim 1 or 2, wherein the monomer represented by the formula (III) is a monomer represented by the formula (a1-1).

[In the formula (a1-1),
L ^a1 represents —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—.
R ^a4 represents a hydrogen atom or a methyl group.
R ^a6 represents an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14. ] X ¹ represents a single bond or —CO—O—X ³ — ^* [ ^* represents a bond to —CO—, and X ³ represents an alkylene group having 1 to 6 carbon atoms. ] The manufacturing method of resin in any one of Claims 1-3. X < ² > is a single bond, The manufacturing method of resin in any one of Claims 1-4.   A resist composition comprising a resin obtained by the method for producing a resin according to claim 1 and an acid generator. (1) The process of apply | coating the resist composition of Claim 6 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure,
(5) A method for producing a resist pattern including a step of developing the composition layer after heating.