JP2017161717A - Resist Composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition that has good handling property and a low viscosity when a resist pattern is to be formed from the resist composition, and that allows easy and simple production of a resist pattern in a relatively thick film state.SOLUTION: The resist composition comprises a resin including a structural unit having an acid-labile group, an acid generator and a solvent. The resist composition contains the solvent by 100 parts by mass or more with respect to 100 parts by mass of the resin, and has a viscosity of 120 cp or less.SELECTED DRAWING: None

Description

  The present invention relates to a resist composition.

  Patent Document 1 describes a resist composition containing a resin in which a phenolic hydroxyl group in polyhydroxystyrene is protected, an acid generator, and a mixed solvent containing butyl acetate.

Japanese Patent Laid-Open No. 4-92662

  When forming a resist pattern from a resist composition, a material having good handling properties and a low viscosity is required, while a material that can be easily and easily formed with a relatively thick film is also required. Yes.

［式（ａ１−０）及び式（ａ１−４）中、
Ｒ^ａ０１及びＲ^ａ３２は、互いに独立に、水素原子又はメチル基を表す。
Ｌ^ａ０１は、酸素原子又は＊−Ｏ−（ＣＨ_２）_ｋ０１−ＣＯ−Ｏ−を表し、ｋ０１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。
Ｒ^ａ０２、Ｒ^ａ０３及びＲ^ａ０４は、互いに独立に、炭素数１〜１２のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合せた基を表すか、Ｒ^ａ０３及びＲ^ａ０４は互いに結合してそれらが結合する炭素原子とともに炭素数３〜２０の２価の環を形成し、該環に含まれるメチレン基は、酸素原子又は硫黄原子で置き換わってもよい。該環に含まれる水素原子は、炭素数１〜８のアルキル基で置換されていてもよい。
Ｒ^ａ３３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。
Ｒ^ａ３４及びＲ^ａ３５は、互いに独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｒ^ａ３６は、炭素数１〜２０の炭化水素基を表す。
ｌａは、０〜４の整数を表す。］
〔８〕〔１〕〜〔７〕のいずれかに記載のレジスト組成物から得られた膜。
〔９〕膜の厚さが、６μｍ以上の厚さである〔８〕に記載の膜。 The present invention includes the following inventions.
[1] A resist composition comprising a resin containing a structural unit having an acid labile group, an acid generator and a solvent,
The content of the solvent is 100 parts by mass or more with respect to 100 parts by mass of the resin,
And the resist composition whose viscosity of the said resist composition is 120 cp or less.
[2] The resist composition according to [1], wherein the solvent contains an acetate ester.
[3] The resist composition according to [2], wherein the acetate ester contains butyl acetate.
[4] The resist composition according to [2] or [3], wherein the solvent contains 40% by mass or more of acetate ester with respect to the total solvent.
[5] The resist composition according to any one of [1] to [4], further containing a surfactant.
[6] The resist composition according to [5], wherein the content of the surfactant is 0.01% by mass or more and 1% by mass or less with respect to the resist composition.
[7] The structural unit having an acid labile group is a structural unit represented by formula (I) or a structural unit represented by formula (a1-0): Resist composition.

[In Formula (a1-0) and Formula (a1-4),
R ^a01 and R ^a32 each independently represent a hydrogen atom or a methyl group.
L ^a01 represents an oxygen atom or * —O— (CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond to a carbonyl group.
R ^a02 , R ^a03 and R ^a04 each independently ^represent an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof, or R ^a03 and R ^a04 Are bonded to each other to form a divalent ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, and the methylene group contained in the ring may be replaced with an oxygen atom or a sulfur atom. The hydrogen atom contained in the ring may be substituted with an alkyl group having 1 to 8 carbon atoms.
R ^a33 represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.
R ^a34 and ^{R a35} are independently of each other, represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
R ^a36 represents a hydrocarbon group having 1 to 20 carbon atoms.
la represents an integer of 0 to 4. ]
[8] A film obtained from the resist composition according to any one of [1] to [7].
[9] The film according to [8], wherein the film thickness is 6 μm or more.

  According to the resist composition of the present invention, the handleability is good, the viscosity is low, and the resist pattern can be easily and easily produced with a relatively thick film.

In the present specification, “(meth) acrylate” means “at least one of acrylate and methacrylate”. Notations such as “(meth) acrylic acid” and “(meth) acryloyl” have the same meaning.
Further, unless otherwise specified, a group that can be linear or branched, such as an “aliphatic hydrocarbon group”, includes both of them. The “aromatic hydrocarbon group” also includes a group in which a hydrocarbon group is bonded to an aromatic ring. When stereoisomers exist, all stereoisomers are included.
In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent described later from the total amount of the resist composition.

[Resist composition]
The resist composition of the present invention comprises:
A resin containing a structural unit having an acid labile group (hereinafter sometimes referred to as “resin (A1)”),
It contains an acid generator (hereinafter sometimes referred to as “acid generator (B)”) and a solvent (hereinafter sometimes referred to as “solvent (E)”).
In this resist composition, 100 parts by mass or more of the solvent (E) is contained with respect to 100 parts by mass of the resin. Moreover, a viscosity is 120 cp or less.
Furthermore, the resist composition contains a resin not containing a structural unit having an acid labile group (hereinafter sometimes referred to as “resin (A2)”), a quencher, a surfactant and / or other additives. May be.

<Resin (A1)>
The resin (A1) includes a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a1)”). Here, the “acid labile group” is a group having a leaving group, and the leaving group is eliminated by contact with an acid to have a hydrophilic group (for example, a hydroxy group or a carboxyl group). Means a group converted to a unit. Acid labile groups include protecting groups that can be cleaved by the action of acids.
The resin (A1) further includes a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”) and / or other structural unit (hereinafter referred to as “structural unit (t)”). May be included).

［式（１）中、Ｒ^ａ１〜Ｒ^ａ３は、互いに独立に、炭素数１〜１２のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合せた基を表すか、Ｒ^ａ１及びＲ^ａ２は互いに結合してそれらが結合する炭素原子とともに炭素数３〜２０の２価の脂環式炭化水素基を形成し、該２価の脂環式炭化水素基に含まれる水素原子は、炭素数１〜８のアルキル基で置換されていてもよい。
ｎａは、０又は１を表す。
＊は結合手を表す。］ The acid labile group contained in the resin (A) is preferably the group (1) and / or the group (2).

[In Formula (1), R ^<a1 > -R < ^a3 > represents a C1-C12 alkyl group, a C3-C20 alicyclic hydrocarbon group, or the group which combined these independently each other, or R ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, and a hydrogen atom contained in the divalent alicyclic hydrocarbon group May be substituted with an alkyl group having 1 to 8 carbon atoms.
na represents 0 or 1.
* Represents a bond. ]

［式（２）中、Ｒ^ａ１’及びＲ^ａ２’は、互いに独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ３’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^ａ２’及びＲ^ａ３’は互いに結合してそれらが結合する炭素原子及びＸとともに炭素数３〜２０の２価の複素環基を形成し、該炭化水素基及び該２価の複素環基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｓ−で置き換わってもよい。
Ｘは、酸素原子又は硫黄原子を表す。
＊は結合手を表す。］

[In the formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent heterocyclic group having 3 to 20 carbon atoms together with the carbon atom and X to which they are bonded, and the hydrocarbon group and the divalent heterocyclic group. —CH ₂ — contained in the ring group may be replaced by —O— or —S—.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

^Examples of the alkyl group for R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, a 2-ethylpropyl group, an n-hexyl group, and 2-methylhexyl. Group, n-heptyl group, n-octyl group and the like.
The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, and norbornyl. And the following groups (* represents a bond). The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 is preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms.

Examples of the group combining an alkyl group and an alicyclic hydrocarbon group include, for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, methyladamantyl group, cyclohexylmethyl group, adamantylmethyl group, norbornyl An ethyl group etc. are mentioned.
na is preferably 0.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group include the following groups. The divalent alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

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

Ｒ^ａ１’及びＲ^ａ２’のうち、少なくとも１つは水素原子であることが好ましい。 Examples of the hydrocarbon group of R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the group obtained by combining an alkyl group and an aromatic hydrocarbon group include aralkyl groups such as a benzyl group and a phenethyl group.
^{Examples of the} divalent heterocyclic group formed together with the carbon atom to which R ^{a2 ′} and R ^{a3 ′} are bonded to each other and X, and X include the following groups. * Represents a bond.

Of R ^{a1 ′} and R ^{a2 ′} , at least one is preferably a hydrogen atom.

Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

  The structural unit having an acid labile group is preferably a structural unit having an acid labile group and an ethylenically unsaturated bond, more preferably a structural unit derived from a (meth) acrylic monomer having an acid labile group. .

  Among structural units derived from a (meth) acrylic monomer having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferred. If the resin (A) having a structural unit derived from a monomer having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

  The structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1) is preferably a structural unit represented by the formula (a1-0). The structural unit represented by the formula (a1-0) includes, for example, the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2). These may be used alone or in combination of two or more. In this specification, the structural unit represented by formula (a1-0), the structural unit represented by formula (a1-1), and the structural unit represented by formula (a1-2) are each represented by structural unit (a1). -0), structural unit (a1-1) and structural unit (a1-2), a monomer for deriving structural unit (a1-0), a monomer for deriving structural unit (a1-1), and a structural unit (a1- The monomer that induces 2) may be referred to as monomer (a1-0), monomer (a1-1), and monomer (a1-2), respectively.

［式（ａ１−０）中、
Ｌ^ａ０１は、酸素原子又は＊−Ｏ−（ＣＨ_２）_ｋ０１−ＣＯ−Ｏ−を表し、ｋ０１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。
Ｒ^ａ０１は、水素原子又はメチル基を表す。
Ｒ^ａ０２、Ｒ^ａ０３及びＲ^ａ０４は、互いに独立に、炭素数１〜１２のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合せた基を表すか、Ｒ^ａ０３及びＲ^ａ０４は互いに結合してそれらが結合する炭素原子とともに炭素数３〜２０の２価の環を形成し、該環に含まれるメチレン基は、酸素原子又は硫黄原子で置き換わってもよい。該環に含まれる水素原子は、炭素数１〜８のアルキル基で置換されていてもよい。］

[In the formula (a1-0),
L ^a01 represents an oxygen atom or * —O— (CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond to a carbonyl group.
R ^a01 represents a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 each independently ^represent an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof, or R ^a03 and R ^a04 Are bonded to each other to form a divalent ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, and the methylene group contained in the ring may be replaced with an oxygen atom or a sulfur atom. The hydrogen atom contained in the ring may be substituted with an alkyl group having 1 to 8 carbon atoms. ]

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^ａ１及びＬ^ａ２は、互いに独立に、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_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、互いに独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７は、互いに独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合せることにより形成される基を表す。
ｍ１は、０〜１４の整数を表す。
ｎ１は、０〜１０の整数を表す。
ｎ１’は、０〜３の整数を表す。］

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —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 a group formed by combining an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1 ′ represents an integer of 0 to 3. ]

L ^a01 is preferably an oxygen atom or * —O— (CH ₂ ) _k01 —CO—O—, wherein k01 is preferably an integer of 1 to 4, and more preferably 1. L ^a01 is more preferably an oxygen atom.
Examples of the alkyl group of R ^a02 , R ^a03, and R ^a04 , the alicyclic hydrocarbon group, and the group obtained by combining these include the same groups as those ^exemplified for R ^{a1 to} R ^a3 of formula (1).
Carbon number of the alkyl group of R ^a02 , R ^a03 and R ^a04 is preferably 6 or less.
The carbon number of the alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 is preferably 3 or more and 8 or less, more preferably 3 or more and 6 or less.
The group in which the alkyl group and the alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in combination of the alkyl group and the alicyclic hydrocarbon group. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group.

L ^a1 and L ^a2 are independently of each other preferably —O— or * —O— (CH ₂ ) _{k1 ′} —CO—O—, wherein k1 ′ is an integer of 1 to 4, Preferably it is 1.
L ^a1 and L ^a2 are more preferably —O—.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and the group obtained by combining these include the same groups as those ^exemplified for R ^{a1 to} R ^a3 of formula (1).
Carbon number of the alkyl group of R ^a6 and R ^a7 is preferably 6 or less.
Carbon number of the alicyclic hydrocarbon group of R ^a6 and R ^a7 is preferably 3 or more and 8 or less, more preferably 3 or more and 6 or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As the structural unit (a1-0), a structural unit represented by the formula (a1-0-1) to the formula (a1-1-12) and a methyl group corresponding to R ^a01 in these structural units are hydrogen atoms. The substituted structural unit is mentioned, Preferably it is a structural unit represented by either of Formula (a1-0-1)-Formula (a1-1-10).

As a monomer (a1-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned. Among these, monomers represented by the following formulas (a1-1-1) to (a1-1-8) are preferable, and monomers represented by the formulas (a1-1-1) to (a1-1-4) are preferable. Is more preferable.

As the monomer (a1-2), 1-methylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, 1-ethylcycloheptan-1-yl (meth) acrylate, 1-ethylcyclooctane-1-yl (meth) acrylate, 1-isopropylcyclopentan-1-yl (Meth) acrylate and 1-isopropylcyclohexane-1-yl (meth) acrylate are mentioned. Among these, monomers represented by the following formulas (a1-2-1) to (a1-2-12) are preferable, and the formulas (a1-2-3), (a1-2-4), and (a1- 2-9) and a monomer represented by formula (a1-2-10) are more preferred, and a monomer represented by formula (a1-2-3) and formula (a1-2-9) is more preferred.

  When the resin (A1) includes the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is the total structure of the resin (A1). It is 10-95 mol% normally with respect to the sum total of a unit, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

［式（ａ１−３）中、
Ｒ^ａ９は、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、水素原子又は−ＣＯＯＲ^ａ１３を表す。
Ｒ^ａ１３は、炭素数１〜８の脂肪族炭化水素基、炭素数３〜２０の脂環式炭化水素基、又はこれらを組合せることにより形成される基を表し、該脂肪族炭化水素基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基で置換されていてもよく、該脂肪族炭化水素基及び該脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ｒ^ａ１０、Ｒ^ａ１１及びＲ^ａ１２は、互いに独立に、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合せることにより形成される基を表すか、又は、Ｒ^ａ１２は、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合せることにより形成される基を表し、Ｒ^ａ１０及びＲ^ａ１１は互いに結合して、それらが結合する炭素原子とともに炭素数２〜２０の２価の炭化水素基を形成する。 Furthermore, examples of the structural unit (a1) having a group represented by the formula (1) include a structural unit represented by the formula (a1-3). The structural unit represented by the formula (a1-3) may be referred to as a structural unit (a1-3). Moreover, the monomer which derives the structural unit (a1-3) may be referred to as a monomer (a1-3).

[In the formula (a1-3),
R ^a9 represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxy group, a carboxy group, a cyano group, a hydrogen atom, or —COOR ^a13 .
R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these, and the aliphatic hydrocarbon group and The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group, and —CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is —O—. Alternatively, it may be replaced by -CO-.
R ^a10 , R ^a11 and R ^a12 each independently represent a C 1-8 alkyl group, a C 3-20 alicyclic hydrocarbon group or a group formed by combining these, ^{or, R a12} is an alkyl group having 1 to 8 carbon atoms, represent a group formed by combining these alicyclic hydrocarbon group or 3 to 20 carbon ^{atoms, R a10} and ^{R a11} are bonded to each other Thus, a divalent hydrocarbon group having 2 to 20 carbon atoms is formed together with the carbon atom to which they are bonded.

Here, -COOR ^a13 includes a group in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group or an ethoxycarbonyl group.

Examples of the aliphatic hydrocarbon group which may have a hydroxyl group of ^Ra9 include a methyl group, an ethyl group, an n-propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms represented by R ^a13 include a methyl group, an ethyl group, and an n-propyl group.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by Ra13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantylmethyl group, a 1-adamantyl-1-methylethyl group, and 2-oxo-oxolane-3- Yl group and 2-oxo-oxolan-4-yl group.
^Examples of the alkyl group for R ^{a10 to} R ^a12 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, an n-pentyl group, an n-hexyl group, Examples include n-heptyl group, 2-ethylhexyl group and n-octyl group.
The alicyclic hydrocarbon group of R ^{a10 to} R ^a12 may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, Examples thereof include cycloalkyl groups such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cycloheptyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkane-1-yl group, norbornyl group, A methyl norbornyl group and an isobornyl group are mentioned.
As -C (R ^a10 ) (R ^a11 ) (R ^a12 ) in the case where R ^a10 and R ^a11 are bonded to each other to form a divalent hydrocarbon group together with the carbon atom to which they are bonded, Groups are preferred.

  Specific examples of the monomer (a1-3) include 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, and 5-norbornene-2-carboxylic acid. Acid 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1- (4 -Methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4-oxo (Cyclohexyl) ethyl and 1- (1-adamantyl) -1-methyl 5-norbornene-2-carboxylate Chill, and the like.

  Since the resin (A1) containing the structural unit (a1-3) contains a three-dimensionally bulky structural unit, the resist composition containing such a resin (A1) can be resisted at a higher resolution. A pattern can be obtained. Further, since a rigid norbornane ring is introduced into the main chain, the resulting resist pattern tends to be excellent in dry etching resistance.

  When resin (A1) contains structural unit (a1-3), it is preferable that the content rate is 10-95 mol% with respect to the sum total of all the structural units of resin (A1), 15-90 mol. % Is more preferable, and 20 to 85 mol% is still more preferable.

［式（ａ１−４）中、
Ｒ^ａ３２は、互いに独立に、水素原子又はメチル基を表す。
Ｒ^ａ３３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。
Ｒ^ａ３４及びＲ^ａ３５は、互いに独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｒ^ａ３６は、置換基を有していてもよい炭素数１〜２０の炭化水素基を表す。Ｒ^ａ３５及びＲ^ａ３６は互いに結合してそれらが結合する炭素原子及び酸素原子とともに炭素数３〜２０の２価の複素環基を形成し、該炭化水素基及び該２価の複素環基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｓ−で置き換わってもよい。
ｌａは、０〜４の整数を表す。］ As the structural unit (a1) having a group represented by the group (2), a structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as “structural unit (a1-4)”). Can be mentioned.

[In the formula (a1-4),
R ^a32 represents a hydrogen atom or a methyl group independently of each other.
R ^a33 represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.
R ^a34 and ^{R a35} are independently of each other, represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
R ^a36 represents an ^optionally substituted hydrocarbon group having 1 to 20 carbon atoms. R ^a35 and R ^a36 are bonded to each other to form a divalent heterocyclic group having 3 to 20 carbon atoms together with the carbon and oxygen atoms to which they are attached, contained in the heterocyclic group of the hydrocarbon group and the divalent more -CH ₂ - may be replaced by -O- or -S-.
la represents an integer of 0 to 4. ]

R ^a34 and ^{R a35} include the same groups as ^{R a1 'and R a2'} of formula (2).
R ^a36 includes an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, and a group formed by combining these. Can be mentioned.
Examples of the substituent for the hydrocarbon group of ^Ra36 include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom, and aryloxy having 6 to 10 carbon atoms.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the aryloxy group, phenyloxy group, naphthyloxy group, p-methylphenyloxy group, p-tert-butylphenyloxy group, tolyloxy group, xylyloxy group, 2,6-diethylphenyloxy group, 2-methyl-6 -An ethylphenyloxy group etc. are mentioned.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group and an ethoxy group, and further preferably a methoxy group.
As la, 0 or 1 is preferable, and 0 is more preferable.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a methyl group or an ethyl group.
The hydrocarbon group for ^Ra36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. It is a group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms.
The alkyl group and the alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted.
When the aromatic hydrocarbon group in R ^a36 has a substituent, the substituent is preferably an aryloxy group having 6 to 10 carbon atoms.

Examples of the monomer that leads to the structural unit (a1-4) include monomers described in JP 2010-204646 A. Especially, the monomer represented by Formula (a1-4-1)-Formula (a1-4-18) is preferable, and the monomer represented by Formula (a1-4-1)-Formula (a1-4-5) is preferable. More preferred.

  When resin (A1) has a structural unit (a1-4), it is preferable that the content rate is 10-95 mol% with respect to the sum total of all the structural units of resin (A1), 15-90. More preferably, it is mol%, and further preferably 20-85 mol%.

［式（ａ１−５）中、
Ｒ^ａ８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。
Ｚ^ａ１は、単結合又は＊−（ＣＨ_２）_ｈ３−ＣＯ−Ｌ^５４−を表し、ｈ３は１〜４の整数を表し、＊は、Ｌ^５１との結合手を表す。
Ｌ^５１〜Ｌ^５４は、互いに独立に、炭素原子、−Ｏ−又は−Ｓ−を表す。ただし、Ｌ^５１及びＬ^５４の少なくとも一方は酸素原子である。
ｓ１は、１〜３の整数を表す。ｓ１’は、０〜３の整数を表す。］ As a structural unit derived from a (meth) acrylic monomer having a group represented by the formula (2), a structural unit represented by the formula (a1-5) (hereinafter referred to as “structural unit (a1-5)”) Is also included).

[In the formula (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or * — (CH ₂ ) _{h 3} —CO—L ⁵⁴ —, h 3 represents an integer of 1 to 4, and * represents a bond to L ⁵¹ .
L ^{51 to} L ⁵⁴ each independently represent a carbon atom, —O— or —S—. However, at least one of L ⁵¹ and L ⁵⁴ is an oxygen atom.
s1 represents an integer of 1 to 3. s1 ′ represents an integer of 0 to 3. ]

As a halogen atom, a fluorine atom and a chlorine atom are mentioned, Preferably a fluorine atom is mentioned. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group and a trifluoromethyl group. Groups.
In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
One of L ⁵² and L ⁵³ is preferably —O—, and the other is preferably —S—.
s1 is preferably 1.
It is preferable that s1 'is an integer of 0-2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

As a monomer which introduce | transduces structural unit (a1-5), the monomer described in Unexamined-Japanese-Patent No. 2010-61117 is mentioned, for example. Among these, monomers represented by formulas (a1-5-1) to (a1-5-7) are preferable, and monomers represented by formula (a1-5-1) or formula (a1-5-3) are preferable. Is more preferable.

  When resin (A) has a structural unit (a1-5), it is preferable that the content rate is 1-50 mol% with respect to the sum total of all the structural units of resin (A), 3-45 It is more preferable that it is mol%, and it is further more preferable that it is 5-40 mol%.

<Structural unit without acid labile group>
The structural unit (s) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). Examples of the monomer (s) include monomers having no acid labile group, which are well known in the resist field. Preferred structural units are structural units having a hydroxy group or a lactone ring and having no acid labile group. A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group From a resist composition containing a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”), a resist pattern with improved resolution and adhesion to the substrate can be formed.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group. As a structural unit (a2), 1 type may be included independently and 2 or more types may be included.

  Examples of the structural unit (a2) having a phenolic hydroxy group include a structural unit represented by the formula (a2-0) (hereinafter sometimes referred to as “structural unit (a2-0)”).

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

[In the formula (a2-0),
R ^a30 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have 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 acryloyloxy group, or Represents a methacryloyloxy group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ^a31 may be the same as or different from each other. ]

^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom of R ^a30 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 1 , 1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl Group, n-perfluorohexyl group and the like.
R ^a30 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
^Examples of the alkoxy group for R ^a31 include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group, preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group. In addition, a methoxy group is preferable.
Examples of the acyl group for R ^a31 include an acetyl group, a propionyl group, and a butyryl group.
^Examples of the acyloxy group for R ^a31 include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
As ma, 0, 1 or 2 is preferable, 0 or 1 is more preferable, and 0 is more preferable.

Examples of the monomer that derives the structural unit (a2-0) include monomers described in JP 2010-204634 A.
Among them, the structural unit (a2-0) is represented by formula (a2-0-1), formula (a2-0-2), formula (a2-0-3), and formula (a2-0-4), respectively. The structural unit represented by the formula (a2-0-1) or the formula (a2-0-2) is more preferable.

  The resin (A1) containing the structural unit (a2-0) is subjected to a polymerization reaction using a monomer in which the phenolic hydroxy group of the monomer that derives the structural unit (a2-0) is protected with a protective group, and then deprotected It can be manufactured by processing. However, when the deprotection treatment is performed, the acid labile group of the structural unit (a1) needs to be not significantly impaired. Examples of such protecting groups include acetyl groups.

  When the resin (A1) has a structural unit (a2-0) having a phenolic hydroxy group, the content is 5 to 95 mol% with respect to the total of all the structural units of the resin (A1). Is preferable, it is more preferable that it is 10-80 mol%, and it is further more preferable that it is 15-80 mol%.

［式（ａ２−１）中、
Ｌ^ａ３は、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ２−ＣＯ−Ｏ−を表し、ｋ２は、１〜７の整数を表す。＊は−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、互いに独立に、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。］ Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”).

[In the formula (a2-1),
L ^a3 represents —O— or * —O— (CH ₂ ) _k2 —CO—O—, and k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
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. ]

In formula (a2-1), L ^a3 is preferably —O—, —O— (CH ₂ ) _f1 —CO—O— (wherein f1 is an integer of 1 to 4), more preferably -O-.
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.

  Examples of the monomer that derives the structural unit (a2-1) include monomers described in JP 2010-204646 A. Among these, a monomer represented by any one of the formulas (a2-1-1) to (a2-1-6) is preferable, and any one of the formulas (a2-1-1) to (a2-1-4) is preferable. Is more preferable, and a monomer represented by the formula (a2-1-1) or the formula (a2-1-3) is more preferable.

  When the resin (A1) contains the structural unit (a2-1), the content is usually 1 to 45 mol%, preferably 1 to 40 mol, based on the total of all the structural units of the resin (A1). %, More preferably 1 to 35 mol%, and still more preferably 2 to 20 mol%.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. But you can. Among the lactones, a bridged ring including a γ-butyrolactone ring or a γ-butyrolactone ring structure is preferable.

［式（ａ３−１）中、
Ｌ^ａ４は、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^ａ１８は、水素原子又はメチル基を表す。
Ｒ^ａ２１は炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は、０〜５の整数を表す。ｐ１が２以上のとき、複数のＲ^ａ２１は互いに同一であっても異なってもよい。
式（ａ３−２）中、
Ｌ^ａ５は、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^ａ１９は、水素原子又はメチル基を表す。
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す。
ｑ１は、０〜３の整数を表す。ｑ１が２以上のとき、複数のＲ^ａ２２は互いに同一であっても異なってもよい。
式（ａ３−３）中、
Ｌ^ａ６は、−Ｏ−又は＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^ａ２０は、水素原子又はメチル基を表す。
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す。
ｒ１は、０〜３の整数を表す。
式（ａ３−４）中、
Ｒ^ａ２４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^ａ２５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す。
Ｌ^ａ７は、単結合、^＊−Ｌ^ａ８−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−、^＊−Ｌ^ａ８−ＣＯ−Ｏ−Ｌ^ａ９−ＣＯ−Ｏ−又は^＊−Ｌ^ａ８−Ｏ−ＣＯ−Ｌ^ａ９−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ｌ^ａ８及びＬ^ａ９は、互いに独立に、炭素数１〜６のアルカンジイル基を表す。
ｗ１は、０〜８の整数を表す。ｗ１が２以上のとき、複数のＲ^ａ２５は互いに同一であってもよく、異なってもよい。］ The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). These 1 type may be contained independently and 2 or more types may be contained.

[In the formula (a3-1),
L ^a4 represents a group represented by —O— 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.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 may be the same as or different from each other.
In formula (a3-2),
L ^a5 represents a group represented by —O— or * —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 may be the same as or different from each other.
In formula (a3-3),
L ^a6 represents a group represented by —O— 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.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3.
In formula (a3-4),
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom.
R ^a25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
L ^a7 is a single bond, ^* —L ^a8 —O—, ^* —L ^a8 —CO—O—, ^* —L ^a8 —CO—O—L ^a9 —CO—O— or ^* —L ^a8 —O—CO ^-La9- O- is represented.
* Represents a bond with -O-.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
w1 represents an integer of 0 to 8. When w1 is 2 or more, the plurality of R ^a25 may be the same as or different from each other. ]

Examples of the aliphatic hydrocarbon group such as R ^a21 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group.
Examples of the halogen atom for R ^a24 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
^Examples of the alkyl group for R ^a24 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. , Preferably it is a C1-C4 alkyl group, More preferably, it is a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom of R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluoro group. A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group, etc. are mentioned.

^Examples of the alkanediyl group represented by L ^a8 and L ^a9 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, 4-diyl group, 2-methylbutane-1,4-diyl group, etc. are mentioned.

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 are independently of each other preferably —O— or k 3 is an integer of 1 to 4 * —O— (CH ₂ ). a group represented by _{k 3} —CO—O—, more preferably —O— and * —O—CH ₂ —CO—O—, and still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are independently of each other preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are independently of each other preferably an integer of 0 to 2, more preferably 0 or 1.

In formula (a3-4),
R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.
L ^a7 is preferably a single bond or ^* -L ^a8 —CO—O—, and more preferably a single bond, —CH ₂ —CO—O— or —C ₂ H ₄ —CO—O—. .

  As monomers for deriving the structural unit (a3), monomers described in JP 2010-204646 A, monomers described in JP 2000-122294 A, monomers described in JP 2012-41274 A are listed. Can be mentioned. As the structural unit (a3), formula (a3-1-1) to formula (a3-1-4), formula (a3-2-1) to formula (a3-2-4), formula (a3-3) 1) to a structural unit represented by any one of the formula (a3-3-4) and the formula (a3-4-1) to the formula (a3-4-12), the formula (a3-1-1), It is represented by any one of formula (a3-1-2), formula (a3-2-3) to formula (a3-2-4) and formula (a3-4-1) to formula (a3-4-12) The structural unit represented by any one of formulas (a3-4-1) to (a3-4-12) is more preferred, and the structural unit represented by formula (a3-4-1) to formula (a3- The structural unit represented by any one of 4-6) is even more preferable.

In the structural units represented by the following formulas (a3-4-1) to (a3-4-12), compounds in which the methyl group corresponding to R ^a24 is replaced with a hydrogen atom are also structural units (a3-4). ).

When the resin (A1) includes the structural unit (a3), the content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on the total of all the structural units of the resin (A1). Yes, more preferably 10 to 60 mol%.
Moreover, the content rate of a structural unit (a3-1), a structural unit (a3-2), and a structural unit (a3-3) is 5 to 5 with respect to the sum total of all the structural units of resin (A1) mutually independently. It is preferably 60 mol%, more preferably 5 to 50 mol%, and even more preferably 10 to 50 mol%.

  As monomers for deriving the structural unit (s), acrylic acid, methacrylic acid, crotonic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, styrene, α-methylstyrene, 4-methylstyrene, It may be 2-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 4-isopropoxystyrene and the like.

  The resin (A1) contains a structural unit derived from a monomer having an adamantyl group (in particular, the structural unit (a1-1)) in an amount of 15 mol% or more based on the content of the structural unit (a1). preferable. When the content of the structural unit having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

Each structural unit constituting the resin (A1) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do. The content rate of each structural unit which resin (A1) has can be adjusted with the usage-amount of the monomer used for superposition | polymerization.
The weight average molecular weight of the resin (A1) is preferably 2,000 or more (more preferably 2,500 or more, more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, and even more preferably 15,000 or less).
In this specification, the weight average molecular weight is a value determined by gel permeation chromatography. Gel permeation chromatography can be measured by the analytical conditions described in the examples.

<Resin (A2)>
Examples of the resin (A2) that does not contain a structural unit having an acid labile group include the structural unit (a2), the structural unit (a3), the structural unit (a5), and structural units derived from other known monomers.
The weight average molecular weight of the resin (A2) is preferably 5,000 or more (more preferably 6,000 or more) and 80,000 or less (more preferably 60,000 or less).
When the resist composition of this invention contains resin (A2), the content becomes like this. Preferably it is 1-60 mass parts with respect to 100 mass parts of resin (A1), More preferably, it is 1-50 mass parts. Yes, more preferably 2 to 40 parts by mass, particularly preferably 2 to 30 parts by mass.

  The total content of the resin (A1) and the resin (A2) is preferably 10% by mass or more and 50% by mass or less, and more preferably 20% by mass or more and 45% by mass or less with respect to the solid content of the resist composition. It is more preferable. The solid content of the resist composition and the resin content relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
The acid generator generates an acid upon exposure, and the generated acid acts catalytically to desorb a group that is eliminated by the acid of the resin (A1).
Specific examples of the acid generator include onium salts (for example, sulfonium salts and iodonium salts), organic halogen compounds (in particular, haloalkyl-s-triazine compounds), compounds having a diazomethane disulfonyl skeleton, and disulfones having an aromatic group. Compounds, sulfone compounds, orthoquinone diazide compounds, sulfonate ester compounds (for example, sulfonate esters of compounds having an aromatic group, sulfonate esters of N-hydroxyimide), and the like. These may contain 1 type independently and may contain 2 or more types. For example,
Diphenyliodonium trifluoromethanesulfonate,
4-methoxyphenylphenyliodonium hexafluoroantimonate,
4-methoxyphenylphenyliodonium trifluoromethanesulfonate,
Bis (4-tert-butylphenyl) iodonium tetrafluoroborate,
Bis (4-tert-butylphenyl) iodonium hexafluorophosphate,
Bis (4-tert-butylphenyl) iodonium hexafluoroantimonate,
Bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate,

Triphenylsulfonium hexafluorophosphate,
Triphenylsulfonium hexafluoroantimonate,
Triphenylsulfonium trifluoromethanesulfonate,
4-methoxyphenyldiphenylsulfonium hexafluoroantimonate,
4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate,
p-tolyldiphenylsulfonium trifluoromethanesulfonate,
2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate,
4-tert-butylphenyldiphenylsulfonium trifluoromethanesulfonate,
4-phenylthiophenyldiphenylsulfonium hexafluorophosphate,
4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate,
1- (2-naphthoylmethyl) thiolanium hexafluoroantimonate,
1- (2-naphthoylmethyl) thiolanium trifluoromethanesulfonate,
4-hydroxy-1-naphthyldimethylsulfonium hexafluoroantimonate,
4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate,

2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine,
2,4,6-tris (trichloromethyl) -1,3,5-triazine,
2-phenyl-4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (4-chlorophenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (4-methoxy-1-naphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (benzo [d] [1,3] dioxolan-5-yl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (4-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (3,4,5-trimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (3,4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (2,4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (2-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (4-butoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,
2- (4-pentyloxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,

1-benzoyl-1-phenylmethyl p-toluenesulfonate (commonly known as benzoin tosylate),
2-benzoyl-2-hydroxy-2-phenylethyl p-toluenesulfonate (commonly known as α-methylol benzoin tosylate),
1,2,3-benzenetriyl trismethanesulfonate,
2,6-dinitrobenzyl p-toluenesulfonate,
2-nitrobenzyl p-toluenesulfonate,
4-nitrobenzyl p-toluenesulfonate,

Diphenyl disulfone,
Di-p-tolyl disulfone,
Bis (phenylsulfonyl) diazomethane,
Bis (4-chlorophenylsulfonyl) diazomethane,
Bis (p-tolylsulfonyl) diazomethane,
Bis (4-tert-butylphenylsulfonyl) diazomethane,
Bis (2,4-xylylsulfonyl) diazomethane,
Bis (cyclohexylsulfonyl) diazomethane,
(Benzoyl) (phenylsulfonyl) diazomethane,

N- (phenylsulfonyloxy) succinimide,
N- (trifluoromethylsulfonyloxy) succinimide,
N- (trifluoromethylsulfonyloxy) phthalimide,
N- (trifluoromethylsulfonyloxy) -5-norbornene-2,3-dicarboximide,
N- (trifluoromethylsulfonyloxy) naphthalimide,
N- (10-camphorsulfonyloxy) naphthalimide and the like.

  The content of the acid generator (B) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, preferably 30 parts by mass or less, with respect to 100 parts by mass of the resin (A1). More preferably, it is 35 parts by mass or less.

<Solvent (E)>
The content rate of a solvent (E) is 50 mass% or more normally in a resist composition, Preferably it is 60 mass% or more. Moreover, it is 99.9 mass% or less normally, Preferably it is 99 mass% or less, More preferably, it is 75 mass% or less, More preferably, it is 73 mass% or less. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography.

  As the solvent (E), glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ether solvents such as propylene glycol monomethyl ether; ester solvents such as ethyl lactate and ethyl pyruvate; acetone Ketone solvents such as methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic ester solvents such as γ-butyrolactone; acetate solvents such as ethyl acetate, methyl acetate, propyl acetate, butyl acetate, amyl acetate and hexyl acetate; ethyl propionate , Propionate solvents such as methyl propionate, propyl propionate, butyl propionate, amyl propionate, hexyl propionate; ethyl butyrate, methyl butyrate And the like; Le, propyl butyrate, butyl butyrate, pentyl butyrate, butyrate solvent such as butyric acid hexyl. The solvent (E) may contain one kind alone, but preferably contains two or more kinds.

In particular, as the solvent (E), those having a high evaporation rate and a low viscosity are preferable, and acetic acid esters, propionic acid esters and / or butyric acid esters are preferable. Of these, acetates are preferable.
The content of acetate is preferably 40% by mass or more, more preferably 45% by mass or more, and preferably 60% by mass or less, and 57% by mass or less, based on the total solvent. It is more preferable. In particular, the content of butyl acetate is preferably 40% by mass or more, and more preferably 45% by mass or more.

  Thus, handling property can be improved by using the solvent (E) having a relatively high evaporation rate and low viscosity. In addition, when the viscosity is low, it is possible to reduce the load caused by the viscosity on the apparatus and parts used at the time of film formation of the resist composition. In addition, damage and wear of parts and the like can be avoided. Furthermore, since it has a moderate evaporation rate, it is possible to prevent the sequential evaporation of the solvent and to apply the resist composition uniformly during film formation.

<Quencher (C)>
Examples of the quencher (C) include a salt that generates an acid having a weaker acidity than a basic nitrogen-containing organic compound or an acid generated from the acid generator (B).
Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

  Examples of the amine 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, tripentylamine, trihexylamine, tri Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, Rudicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyl Didecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, piperazine, morpholine, piperidine and JP-A-11- Hindered amine compounds having a piperidine skeleton described in Japanese Patent No. 2575, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 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) Examples include ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipicolylamine, bipyridine, and the like. Includes diisopropylaniline, more preferably 2,6-diisopropylaniline.

  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.

  In addition, a hindered amine compound having a hindered piperidine skeleton described in JP-A No. 11-52575 can be used as a quencher.

  When the resist composition contains the quencher (C), the content thereof is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass in the solid content of the resist composition. Particularly preferred is 0.01 to 4% by mass.

<Surfactant>
The resist composition of the present invention can contain a surfactant. By including the surfactant, the flatness tends to be good.
Examples of the surfactant include a polyether-modified silicone compound, a surfactant having no silicon atom and a fluorine atom, a surfactant having a silicon atom and a fluorine atom, and a silicone surfactant not modified with a polyether. Can be mentioned. These surfactants may be used alone or in combination of two or more.

  Examples of the polyether-modified silicone compound include BY16-201 (trade name), SF8427 (trade name), SF8428 (trade name), FZ-2162 (trade name), SH3749 (trade name), and FZ-77 (trade name). ), FZ-2110 (trade name), SH8400 (trade name) (manufactured by Toray Dow Corning Co., Ltd.), and the like.

  Examples of the surfactant having a fluorine atom but not having a silicon atom include a surfactant having a fluorocarbon chain. Specifically, Florinert FC430 (trade name), Florinart FC431 (trade name) (manufactured by Sumitomo 3M Limited), Megafuck F142D (tradename), Megafuck F171 (tradename), Megafuck F172 (tradename) , Megafuck F173 (trade name), Megafuck F177 (trade name), Megafuck F183 (trade name), Megafuck R30 (trade name) (Dainippon Ink Chemical Co., Ltd.), F Top EF301 (trade name) ), F-top EF303 (product name), F-top EF351 (product name), F-top EF352 (product name) (manufactured by Shin-Akita Kasei Co., Ltd.), Surflon S381 (product name), Surflon S382 (product name), Surflon SC101 (trade name), Surflon SC105 (trade name) (manufactured by Asahi Glass Co., Ltd.), E5844 ( Name) (Co., Ltd. Daikin Fine Chemical Institute), BM-1000 (trade name), BM-1100 (trade name) (BM Chemie Co., Ltd.) and the like.

  Examples of the surfactant having a silicon atom and a fluorine atom include MegaFuck R08 (trade name), MegaFuck BL20 (trade name), MegaFuck F475 (trade name), MegaFuck F477 (trade name), and Megafuck F443. (Trade name) (manufactured by Dainippon Ink & Chemicals, Inc.).

  Examples of silicone-based surfactants not modified with polyether include Torre Silicone DC3PA (trade name), Torre Silicone SH7PA (trade name), Torre Silicone DC11PA (trade name), Torre Silicone SH21PA (trade name), Torre Silicone SH28PA ( Product Name), Torre Silicone 29SHPA (Product Name), Torre Silicone SH30PA (Product Name), Polyether-modified Silicon Oil SH8400 (Product Name) (manufactured by Torre Silicone Co., Ltd.), KP321 (Product Name), KP322 (Product Name) , KP323 (product name), KP324 (product name), KP326 (product name), KP340 (product name), KP341 (product name) (manufactured by Shin-Etsu Silicone), TSF400 (product name), TSF401 (product name), TSF410 ( Product name), T F4300 (product name), TSF4440 (product name), TSF4445 (product name), TSF-4446 (product name), TSF4452 (product name), TSF4460 (product name) (manufactured by GE Toshiba Silicone Co., Ltd.), and the like. .

  The content of the surfactant is preferably 0.01% by mass or more and 1% by mass or less, more preferably 0.01% by mass or more and 0.5% by mass or less, and still more preferably with respect to the resist composition. Is 0.01 mass% or more and 0.3 mass% or less.

［式（Ｉ）中、
Ｘは、メチレン基又はカルボニル基を表し、
Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４は、互いに独立に、水素原子又は炭素数１〜４のアルキル基を表す。ただし、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４うち二つは低級アルキルを、残りの二つは水素を表す。］ <Additives>
Examples of the additive for the resist composition of the present invention include nitrogen-containing cyclic compounds represented by the formula (I).

[In the formula (I),
X represents a methylene group or a carbonyl group,
R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. However, ^{two of} R ¹ , R ² , R ³ and R ⁴ represent lower alkyl, and the remaining two represent hydrogen. ]

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Of these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. By including such a nitrogen-containing cyclic compound, it is possible to suppress the pattern side surface from becoming corrugated and to obtain a pattern having a smooth side surface.
As such nitrogen-containing cyclic compounds, known ones and commercially available ones can be used. Among these, as the nitrogen-containing cyclic compound, 1,3-dimethyl-2-imidazolidinone and 5,5-dimethylhydantoin are preferable, and 5,5-dimethylhydantoin is more preferable.

  When the resist composition contains the nitrogen-containing cyclic compound represented by the formula (I), the content thereof is preferably 0.01 to 20% by mass, more preferably 0, in the solid content in the resist composition. 0.01 to 10% by mass.

<Other ingredients>
The resist composition may contain components other than those described above (hereinafter may be referred to as “other components (F)”) as necessary. As the other component (F), known additives in the resist field, such as a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, a dye, and the like can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A1), an acid generator (B) and a solvent (E), and a resin (A2), a quencher (C), additives and other components used as necessary. It can be prepared by mixing (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature from 10-40 degreeC according to the kind etc. of resin etc., the solubility with respect to solvents (E), such as resin. The mixing time may be 0.5 to 24 hours depending on the mixing temperature. Mixing means such as a stirring mixer can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

The resist composition of the present invention has a viscosity of 120 cp or less, preferably 118 cp or less, more preferably 110 cp or less, and even more preferably 100 cp or less. The viscosity is represented by a value measured with a Canon-Fenske viscometer at a sample temperature of 20 to 30 ° C, preferably 25 ° C.
By adjusting to such a viscosity, handling properties can be improved, and when forming a resist composition film by using a known film forming method, a thick film resist can be formed by a single operation. A composition film can be formed. In addition, it is possible to reduce the generation of volatile components and / or gas from the resist composition film even when a temperature cycle is applied in a subsequent process after forming a thick resist composition film. An accurate resist pattern can be manufactured.

[Resist pattern manufacturing method]
The method for producing a resist pattern of the present invention comprises:
(1) A step of applying the resist composition of the present invention 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, and (5) a step of developing the composition layer after heating.

The resist composition can be applied onto the substrate by a commonly used apparatus such as a spin coater. The application here is preferably performed so that the thickness of the composition layer to be formed is 6 μm or more, preferably 7 μm or more. Further, the thickness can be secured by a plurality of coating processes, but the thickness can be secured even by a single coating process.
In the resist composition of the present invention, since the viscosity is low and the handling property is good, it is possible to form a film without applying a pressure load due to the viscosity of the resist composition to a normally used film forming apparatus or the like. .
Examples of the substrate include an inorganic substrate such as a silicon wafer. Before applying the resist composition, the substrate may be washed, or an antireflection film or the like may be formed on the substrate.

By drying the composition after coating, the solvent is removed and a composition layer is formed. The thickness of the composition layer here is preferably 6 μm or more, and more preferably 7 μm or more. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or using a decompression device. The heating temperature is preferably 50 to 200 ° C., for example, and the heating time is preferably 10 to 180 seconds, for example. Moreover, it is preferable that the pressure at the time of drying under reduced pressure is about 1-1.0 * 10 < ⁵ > Pa.

  The obtained composition layer is usually exposed using an exposure machine. Although various exposure machines can be used as the exposure light source, a KrF excimer laser (wavelength 248 nm) or I-line (wavelength 365 nm) is preferable. At the time of exposure, exposure is usually performed through a mask corresponding to a required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.

  The composition layer after exposure is preferably subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection reaction in the acid labile group, but it may not be performed. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

  The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example.

  When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkali developer may contain a surfactant.

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

  It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight (Mw) and polydispersity (Mw / Mn) are values measured by gel permeation chromatography using polystyrene as a standard product.
Resin Synthesis Polymers and compounds (monomers) used in resin synthesis are shown below.

Resin synthesis example 1: (Partial 1-ethoxyethylation of polyvinylphenol)
In a 500 ml reaction vessel, 5.8 g of polymer X (manufactured by Nippon Soda Co., Ltd., poly (p-vinylphenol), trade name “VP-15000”), 11 mg of p-toluenesulfonic acid and 114.3 g of propylene glycol monomethyl ether acetate are added. Charged and dissolved at room temperature. Then, it concentrated until the total amount became 70.6g. Thereto was added 2.86 g of ethyl vinyl ether, and the mixture was stirred at room temperature for 3 hours, and 53.4 g of methyl isobutyl ketone was added. Next, the operation of washing with 41.0 g of ion exchange water and separating the liquid was performed three times. After washing with water, the oil layer was concentrated to 38.2 g. To this oil layer, 39.5 g of propylene glycol monomethyl ether acetate was added and concentrated again to a total amount of 37.2 g. A part of this solution was sampled, and the 1-ethoxyethylation rate of the hydroxyl groups was measured by ¹ H-NMR by a conventional method, and found to be 45%. Therefore, in this resin, 45% of the hydroxyl groups of poly (p-vinylphenol) having the following structural units are converted to 1-ethoxyethyl ether. This is called resin R1.

Resin Synthesis Example 2: Synthesis of Resin R2 Monomer A, Monomer B, Monomer C, and Monomer D were charged in a molar ratio of 50: 10: 30: 10, and propylene glycol monomethyl acetate at 1.8 mass times the total monomer amount was added. It was set as the solution. Then, 6.5 mol% of 2,2′-azobis (isobutyric acid) dimethyl as an initiator was added to the total amount of monomers, and heated at 85 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a resin having a weight average molecular weight of 9.3 × 10 ² in a yield of 69%. This resin has a structural unit derived from a monomer represented by the following formula, and this is designated as resin R2.

Resin Synthesis Example 3: Synthesis of Resin R3 Monomer A, Monomer B, Monomer C, and Monomer E were charged in a molar ratio of 50: 10: 30: 20, and 1.8 mass times propylene glycol monomethyl acetate of the total monomer amount was added. It was set as the solution. Then, 4.0 mol% of 2,2′-azobis (isobutyric acid) dimethyl as an initiator was added with respect to the total amount of monomers and heated at 85 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a resin having a weight average molecular weight of 14.4 × 10 ² in a yield of 89%. This resin has a structural unit derived from a monomer of the following formula, and this is designated as resin R3.

Resin Synthesis Example 4: Synthesis of Resin R4 Monomer A, Monomer B, Monomer C, and Monomer E were charged in a molar ratio of 40: 10: 30: 20, and 1.8 mass times propylene glycol monomethyl acetate of the total monomer amount was added. It was set as the solution. Then, 4.0 mol% of 2,2′-azobis (isobutyric acid) dimethyl as an initiator was added with respect to the total amount of monomers and heated at 85 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a resin having a weight average molecular weight of 14.1 × 10 ² at a yield of 89%. This resin has a structural unit derived from a monomer represented by the following formula, and this is designated as resin R4.

Resin Synthesis Example 5: Synthesis of Resin R5 Monomer A, Monomer B, Monomer C, and Monomer F were charged at a molar ratio of 40: 10: 30: 20, and propylene glycol monomethyl acetate at 1.8 mass times the total monomer amount was added. It was set as the solution. Then, 4.0 mol% of 2,2′-azobis (isobutyric acid) dimethyl as an initiator was added with respect to the total amount of monomers and heated at 85 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a resin having a weight average molecular weight of 13.3 × 10 ² in a yield of 86%. This resin has a structural unit derived from a monomer represented by the following formula, and this is designated as resin R5.

<Preparation of resist composition>
Each of the components shown below was dissolved in a solvent in parts by mass shown in Table 1, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition. The amount of solvent includes the amount brought in from the resin solution.

酸発生剤（ＩＶ）：

クエンチャー（C)：トリス［２−（２−メトキシエトキシ）エチル］アミン

溶剤
ＭＰ：メトキシプロパノール
ＰＧＭＥＡ：プロピレングリコールモノメチルエーテルアセテート
ＢＡ：酢酸ブチル
ＰＧＥ：プロピレングリコールモノメチルエーテル
ＭＡＫＮ：２−ヘプタノン
ＧＢＬ：γ−ブチロラクトン
ＥＬ：乳酸エチル
ＭＢＬ：α―メチル−γブチロラクトン
界面活性剤
ポリエーテル変性シリコーンオイル（東レ・ダウコーニング（株）製 ＳＨ８４００） Resin: R1 to R5
Acid generator (III):

Acid generator (IV):

Quencher (C): Tris [2- (2-methoxyethoxy) ethyl] amine

Solvent MP: Methoxypropanol PGMEA: Propylene glycol monomethyl ether acetate BA: Butyl acetate PGE: Propylene glycol monomethyl ether MAKN: 2-heptanone GBL: γ-butyrolactone EL: Ethyl lactate MBL: α-methyl-γ butyrolactone Surfactant Polyether modified Silicone oil (SH8400 manufactured by Toray Dow Corning Co., Ltd.)

(Film formation)
The viscosity of each resist composition was measured at 25 ° C. by Canon Fenske method.
Each resist composition was spin-coated on a silicon wafer at 1500 rpm, and then prebaked on a proximity hot plate under conditions of 100 ° C. for 60 seconds to form a film. The film thickness was measured with Lambda Ace. The results are shown in Table 2.

When the resist compositions of Example 1 and Comparative Example 1 described above were formed, the film thickness of each film was measured at 57 points in the plane, and the CV value (value variation; unit%) of the value was calculated. did. The smaller the CV value, the more uniform the coating film thickness.
Further, five wafers formed using the resist compositions of Example 1 and Comparative Example 1 were scraped, and the amount of PGMEA solvent in the film was measured by gas chromatography. The results are shown in Table 3. A high amount of PGMEA solvent in the membrane is not preferable because it causes outgassing.

  As described above, the resist composition of the present invention containing butyl acetate can maintain the uniformity of the coating film thickness, the amount of residual solvent in the film is the same, and can be suppressed to a low viscosity with the same film thickness. Therefore, by using this composition, a thick resist film can be formed with a low viscosity liquid.

  Since the resist composition of the present invention can be prepared with a low viscosity, it can be formed without applying a load to the film forming apparatus. In addition, since a thick resist composition can be formed while having a low viscosity, it can be easily adjusted to a desired film thickness. Further, the uniformity of the coating film thickness can be ensured, and a good resist pattern can be produced, which is suitable for semiconductor microfabrication.

Claims (9)

A resist composition comprising a resin containing a structural unit having an acid labile group, an acid generator and a solvent,
The content of the solvent is 100 parts by mass or more with respect to 100 parts by mass of the resin,
And the resist composition whose viscosity of the said resist composition is 120 cp or less.   The resist composition according to claim 1, wherein the solvent contains an acetate ester.   The resist composition according to claim 2, wherein the acetate comprises butyl acetate.   The resist composition according to claim 2 or 3, wherein the solvent contains 40% by mass or more of acetate ester with respect to the total solvent.   Furthermore, the resist composition in any one of Claims 1-4 containing surfactant.   The resist composition according to claim 5, wherein the content of the surfactant is 0.01% by mass or more and 1% by mass or less with respect to the resist composition. The resist composition according to claim 1, wherein the structural unit having an acid labile group is a structural unit represented by formula (I) or a structural unit represented by formula (a1-0).

[In Formula (a1-0) and Formula (a1-4),
R ^a01 and R ^a32 each independently represent a hydrogen atom or a methyl group.
L ^a01 represents an oxygen atom or * —O— (CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond to a carbonyl group.
R ^a02 , R ^a03 and R ^a04 each independently ^represent an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof, or R ^a03 and R ^a04 Are bonded to each other to form a divalent ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, and the methylene group contained in the ring may be replaced with an oxygen atom or a sulfur atom. The hydrogen atom contained in the ring may be substituted with an alkyl group having 1 to 8 carbon atoms.
R ^a33 represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.
R ^a34 and ^{R a35} are independently of each other, represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
R ^a36 represents a hydrocarbon group having 1 to 20 carbon atoms.
la represents an integer of 0 to 4. ]   The film | membrane obtained from the resist composition in any one of Claims 1-7.   The film according to claim 8, wherein the film has a thickness of 6 μm or more.