JP2011085913A - Resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition which can produce a resist pattern having good resolution and configuration. <P>SOLUTION: The resist composition comprises a resin comprising a structural unit derived from a monomer represented by formula (1), an acid generator and a solvent, wherein R<SP>1</SP>and R<SP>2</SP>each independently represents H or 1-4C alkyl; A<SP>1</SP>is a single bond or represents a group represented by *1-(CH<SB>2</SB>)<SB>m</SB>-CO-O-*2 or *1-(CH<SB>2</SB>)<SB>n</SB>-CO-NR<SP>3</SP>-*2 (wherein R<SP>3</SP>represents H or 1-4C alkyl; m and n each independently represents an integer of 1-6; *1 is direct link to N; *2 is direct link to B<SP>1</SP>); and B<SP>1</SP>represents a 4-20C lactone ring group which may have a substituent. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resist composition used for semiconductor microfabrication.

  A resist composition used for microfabrication of a semiconductor using a lithography technique contains a resin and an acid generator that generates an acid upon exposure.

  For example, Patent Document 1 discloses a resin containing a structural unit derived from 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, and α-methacryloyloxy-γ-butyrolactone, and triphenyl. A resist composition containing an acid generator composed of sulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate and a solvent is described.

JP 2003-107708 A

  In conventional resist compositions, the resolution and shape of the resulting resist pattern may not always be satisfactory.

［式（１）中、
Ｒ^１及びＲ^２は、それぞれ独立に、水素原子又はＣ_1-4アルキル基を表す。
Ａ^１は単結合、＊１−（ＣＨ_２）_ｍ−ＣＯ−Ｏ−＊２で表される基又は＊１−（ＣＨ_２）_ｎ−ＣＯ−ＮＲ^３＊２で表される基を表す。Ｒ^３は水素原子又はＣ_1-4アルキル基を表す。ｍ及びｎは、それぞれ独立に、１〜６の整数を表し、＊１は窒素原子との、＊２はＢ^１との結合手である。
Ｂ^１は置換基を有していてもよいＣ_4-20ラクトン環基を表す。］
２．前記式（１）のＢ^１が、式（２）又は式（３）で表される基である１．記載のレジスト組成物。

［式（２）中、
ｐは０〜３の整数を表し、Ｒ^４はＣ_1-4アルキル基を表す。ｐが２以上の場合、複数のＲ^４はそれぞれ独立である。
ｑは０〜３の整数を表し、Ｒ^５はカルボキシ基、シアノ基又はＣ_1-4アルキル基を表す。ｑが２以上の場合、複数のＲ^５はそれぞれ独立である。］
３．前記樹脂が、アルカリ水溶液に不溶又は難溶であり、酸の作用によりアルカリ水溶液に可溶となる樹脂である１．又は２．記載のレジスト組成物。
４．前記酸発生剤が、式（Ｂ１）で表される酸発生剤である１．〜３．のいずれか記載のレジスト組成物。

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又はＣ_1-6ペルフルオロアルキル基を表す。
Ｌ^b1は、置換基を有していてもよいＣ_1-17脂肪族炭化水素基又は単結合を表し、該脂肪族炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ｙは、置換基を有していてもよいＣ_1-36脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］
５．前記式（Ｂ１）のＬ^b1が、＊−ＣＯ−Ｏ−（＊は、−Ｃ（Ｑ^１）（Ｑ^２）−との結合手を表す。）である４．記載のレジスト組成物。
６．前記式（Ｂ１）のＺ^＋が、アリールスルホニウムカチオンである４．又は５．記載のレジスト組成物。
７．さらに、塩基性化合物を含有する１．〜６．のいずれか記載のレジスト組成物。
８．前記塩基性化合物が含窒素塩基性化合物である７.記載のレジスト組成物。
９．（１）１．〜８．のいずれか記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物から溶剤を除去して組成物層を形成する工程、
（３）組成物層を露光する工程、
（４）露光後の組成物層を加熱する工程、
（５）加熱後の組成物層を現像する工程、
を含むレジストパターンの製造方法。 The present invention includes the following inventions.
1. A resist composition comprising a resin having a structural unit derived from the monomer represented by formula (1), an acid generator, and a solvent.

[In Formula (1),
R ¹ and R ² each independently represents a hydrogen atom or a C _1-4 alkyl group.
A ¹ represents a single bond, a group represented by * 1- (CH ₂ ) _m —CO—O— * 2, or a group represented by * 1- (CH ₂ ) _n —CO—NR ³ * 2. R ³ represents a hydrogen atom or a C _1-4 alkyl group. m and n each independently represent an integer of 1 to 6, * 1 is of the nitrogen atom, * 2 represents a bond to ^{B 1.}
B ¹ represents a C _4-20 lactone ring group which may have a substituent. ]
2. 1. B ^{1 in the} formula (1) is a group represented by the formula (2) or the formula (3). The resist composition as described.

[In Formula (2),
p represents an integer of 0 to 3, and R ⁴ represents a C _1-4 alkyl group. When p is 2 or more, the plurality of R ⁴ are each independent.
q represents an integer of 0 to 3, and R ⁵ represents a carboxy group, a cyano group, or a C _1-4 alkyl group. When q is 2 or more, the plurality of R ⁵ are each independent. ]
3. 1. The resin is a resin that is insoluble or hardly soluble in an alkaline aqueous solution and becomes soluble in an alkaline aqueous solution by the action of an acid. Or 2. The resist composition as described.
4). 1. The acid generator is an acid generator represented by the formula (B1). ~ 3. The resist composition according to any one of the above.

[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 C _1-17 aliphatic hydrocarbon group or a single bond which may have a substituent, and —CH ₂ — contained in the aliphatic hydrocarbon group is —O— or —CO—. May be replaced.
Y represents an _optionally substituted C _1-36 aliphatic hydrocarbon group, and —CH ₂ — contained in the aliphatic hydrocarbon group is —O—, —SO ₂ — or —CO. -May be substituted.
Z ⁺ represents an organic cation. ]
5). L ^{b1 in the} formula (B1) is * —CO—O— (* represents a bond with —C (Q ¹ ) (Q ² ) —). The resist composition as described.
6). 3. Z ^{+ in the} formula (B1) is an arylsulfonium cation. Or 5. The resist composition as described.
7). Further, it contains a basic compound. ~ 6. The resist composition according to any one of the above.
8). 7. The resist composition according to 7., wherein the basic compound is a nitrogen-containing basic compound.
9. (1) 1. ~ 8. A step of applying the resist composition according to any one of
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure,
(5) a step of developing the composition layer after heating;
A method for producing a resist pattern including:

  According to the resist composition of the present invention, the resolution and shape of the resulting resist pattern can be further improved.

  The resist composition of the present invention (hereinafter sometimes referred to as “the present resist composition”) contains the resin, acid generator and solvent as described above. Hereinafter, each of the constituent components of the resist composition, such as a resin, an acid generator and a solvent, will be described, and a method for preparing the resist composition containing these and a method for producing a resist pattern using the resist composition will be described. explain.

［式（１）中、
Ｒ^１及びＲ^２は、それぞれ独立に、水素原子又はＣ_1-4アルキル基を表す。
Ａ^１は単結合、＊１−（ＣＨ_２）_ｍ−ＣＯ−Ｏ−＊２で表される基又は＊１−（ＣＨ_２）_ｎ−ＣＯ−ＮＲ^３＊２で表される基を表し、Ｒ^３は水素原子又はＣ_1-4アルキル基を表し、ｍ及びｎは、それぞれ独立に、１〜６の整数を表し、＊１は窒素原子との、＊２はＢ^１との結合手である。
Ｂ^１は置換基を有していてもよいＣ_4-20ラクトン環基を表す。］ <Resin (hereinafter referred to as “resin (A)” in some cases)>
The resin (A) has a structural unit derived from the monomer represented by the formula (1) (hereinafter sometimes referred to as “monomer (1)”). Although it repeats, Formula (1) is shown below.

[In Formula (1),
R ¹ and R ² each independently represents a hydrogen atom or a C _1-4 alkyl group.
A ¹ represents a single bond, a group represented by * 1- (CH ₂ ) _m —CO—O— * 2, or a group represented by * 1- (CH ₂ ) _n —CO—NR ³ * 2; R ³ represents a hydrogen atom or a C _1-4 alkyl group, m and n each independently represents an integer of 1 to 6, * 1 is a nitrogen atom, and * 2 is a bond to B ¹ is there.
B ¹ represents a C _4-20 lactone ring group which may have a substituent. ]

  Here, the “lactone ring group” means a group having a lactone structure. Typically, a group obtained by removing one of hydrogen atoms contained in a lactone ring from a compound having a lactone ring is referred to as a “lactone ring group”. The lactone ring contained in the lactone ring group may have a substituent. The lactone ring includes not only a monocyclic lactone ring but also a polycyclic ring in which a lactone ring and another ring are condensed. A preferred lactone ring group will be described later.

The “C _1-4 alkyl group” for R ¹ and R ² means an alkyl group having 1 to 4 carbon atoms. Thus, in this specification, the number of carbon atoms of a group will be shown in a format in which a numerical range is added to “C”. Examples of the C _1-4 alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.
R ¹ and R ² are preferably a hydrogen atom, a methyl group, and an ethyl group, and more preferably a hydrogen atom and a methyl group.
As m and n, the range of 1-4 is preferable, 1 or 2 is more preferable, and 1 is especially preferable.
R ³ is preferably a hydrogen atom, a methyl group or an ethyl group, more preferably a hydrogen atom or a methyl group.
A ¹ is preferably a single bond, * 1-CH ₂ —CO—O— * 2 or * 1-CH ₂ —CO—NH— * 2.

［式（２）中、
ｐは０〜３の整数を表し、Ｒ^４はＣ_1-4アルキル基を表す。ｐが２以上の場合、複数のＲ^４はそれぞれ独立である。
式（３）中、
ｑは０〜３の整数を表し、Ｒ^５は、カルボキシ基、シアノ基又はＣ_1-4アルキル基を表す。ｑが２以上の場合、複数のＲ^５はそれぞれ独立である。
式（４）中、
ｒは０〜３の整数を表し、Ｒ^６は、カルボキシ基、シアノ基又はＣ_1-4アルキル基を表す。ｒが２以上の場合、複数のＲ^６はそれぞれ独立である。］
Ｒ^４、Ｒ^５及びＲ^６におけるＣ_1-4アルキル基の具体例は、Ｒ^１及びＲ^２で例示したものと同じである。 Next, preferred examples of the lactone ring group of B ¹ will be described. As described above, the lactone ring group refers to a group having a lactone structure. Such a lactone ring group is preferably a group represented by the formula (2), the formula (3) or the formula (4).

[In Formula (2),
p represents an integer of 0 to 3, and R ⁴ represents a C _1-4 alkyl group. When p is 2 or more, the plurality of R ⁴ are each independent.
In formula (3),
q represents an integer of 0 to 3, and R ⁵ represents a carboxy group, a cyano group, or a C _1-4 alkyl group. When q is 2 or more, the plurality of R ⁵ are each independent.
In formula (4),
r represents an integer of 0 to 3, and R ⁶ represents a carboxy group, a cyano group, or a C _1-4 alkyl group. When r is 2 or more, the plurality of R ⁶ are each independent. ]
Specific examples of the C _1-4 alkyl group for R ⁴ , R ⁵ and R ⁶ are the same as those exemplified for R ¹ and R ² .

Here, a specific example of the monomer (1) is shown.

［式中、Ｂ^１、Ｒ^１及びＲ^２は、上記と同じ意味を表し、Ａ^１は単結合である。
Ｘは、ハロゲン原子又は（メタ）アクリロイルオキシ基を表す。］ A typical method for producing the monomer (1) will be described.
The monomer (1) in which A ¹ is a single bond can be produced by a production method represented by the following reaction formula.

[Wherein, B ¹ , R ¹ and R ² represent the same meaning as described above, and A ¹ is a single bond.
X represents a halogen atom or a (meth) acryloyloxy group. ]

Examples of the halogen atom in X include a chlorine atom, a bromine atom, and an iodine atom, and among them, a chlorine atom is preferable.
Examples of the compound represented by the formula (1-a) include α-amino-γ-butyrolactone.
Examples of the compound represented by the formula (1-b) include methacrylic acid chloride and methacrylic anhydride.

  The reaction of the compound represented by the formula (1-a) and the compound represented by the formula (1-b) is preferably performed in an inert solvent (for example, an aprotic solvent) in the presence of a base. . Examples of the inert solvent used in this reaction include toluene and tetrahydrofuran, and examples of the base include triethylamine and pyridine.

［式中、Ｂ^１、Ｒ^１及びＲ^２は、上記と同じ意味を表す。Ａ^１は、＊１−（ＣＨ_２）_ｍ−ＣＯ−Ｏ−＊２で表される基又は＊１−（ＣＨ_２）_ｎ−ＣＯ−ＮＲ^３−＊２で表される基（ここで、ｍ、ｎ、＊１及び＊２は上記と同じ意味である。）
Ｘ’は、ハロゲン原子を表す。］ A ¹ is a group represented by * 1- (CH ₂ ) _m —CO—O— * 2 or a monomer represented by * 1- (CH ₂ ) _n —CO—NR ³ — * 2 (1 ) Can be produced by the production method shown in the following reaction formula.

[Wherein, B ¹ , R ¹ and R ² represent the same meaning as described above. A ¹ is a group represented by * 1- (CH ₂ ) _m —CO—O— * 2 or a group represented by * 1- (CH ₂ ) _n —CO—NR ³ — * 2 (where, m, n, * 1, and * 2 have the same meaning as above.)
X ′ represents a halogen atom. ]

Examples of the halogen atom for X ′ are the same as those of X in the formula (1-b), and among them, a chlorine atom is preferable.
Examples of the compound represented by the formula (1-e) include (meth) acrylamide.
Examples of the compound represented by the formula (1-d) include compounds represented by the following.

  The reaction of the compound represented by the formula (1-d) and the compound represented by the formula (1-e) is preferably performed in an inert solvent (for example, an aprotic solvent) in the presence of a catalyst. . Examples of the inert solvent used in this reaction include N, N′-dimethylformamide, and examples of the catalyst include potassium carbonate and potassium iodide.

  Although the manufacturing method of resin (A) is mentioned later, the content rate of the structural unit derived from a monomer (1) is the range of 1-100 mol% by making all the structural units of resin (A) into 100 mol%, Preferably it is the range of 5-80 mol%, More preferably, it is the range of 10-60 mol%. In order to make the content ratio of the structural unit derived from the monomer (1) within this range, the amount of the monomer (A) used may be adjusted with respect to the total amount of monomers used when the resin (A) is produced. In addition, when manufacturing resin (A), multiple types of monomer (A) can also be used, and when multiple types of monomer (A) is used, what is necessary is just to adjust the total amount.

  The resin (A) used in the resist composition is preferably a resin that is insoluble or hardly soluble in an alkaline aqueous solution and becomes soluble in an alkaline aqueous solution by the action of an acid. Such a resin (A) is a monomer (1) and a monomer having an acid labile group (hereinafter sometimes referred to as “acid labile group”) (hereinafter sometimes referred to as “monomer (a1)”). )). In addition, the monomer (a1) used for resin (A) manufacture may be used individually by 1 type, and may use 2 or more types together.

式（１）中、
Ｒ^a1、Ｒ^a2及びＲ^a3（Ｒ^a1〜Ｒ^a3）は、それぞれ独立に、脂肪族炭化水素基を表す。また、Ｒ^a1及びＲ^a2の脂肪族炭化水素基は互いに結合して、これらが結合する炭素原子とともに環を形成していてもよい。＊は結合手を表す。 <Monomer (a1)>
The acid labile group means a group that cleaves a leaving group upon contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). Examples of the acid labile group include an alkoxycarbonyl group represented by the formula (1) in which —O— is bonded to a tertiary carbon atom (excluding the bridgehead carbon atom of the bridged cyclic hydrocarbon group) (that is, 3 Ester bond having a secondary alcohol residue). Hereinafter, the group represented by the formula (1) is sometimes referred to as “acid-labile group (1)”.

In formula (1),
R ^a1 , R ^a2 and R ^a3 (R ^{a1 to} R ^a3 ) each independently represent an aliphatic hydrocarbon group. The aliphatic hydrocarbon groups of R ^a1 and R ^a2 may be bonded to each other to form a ring together with the carbon atom to which they are bonded. * Represents a bond.

Examples of the acid labile group (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), wherein R ^{a1 to} R ^a3 are alkyl groups, preferably a tert-butoxycarbonyl group), 2-alkyl -2-adamantyloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are bonded to form an adamantane ring together with the carbon atom to which these are bonded, and R ^a3 is an alkyl group), and 1- ( 1-adamantyl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

The monomer (a1) having an acid labile group (1) is preferably a monomer further having a carbon-carbon double bond in the molecule, and more preferably has an acid labile group (1) (meta ) Acrylic monomer. In the present specification, "(meth) acrylic monomer" means a monomer having a partial structure of "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- ".

Among the (meth) acrylic monomers having the acid labile group (1G), those having a C _5-20 alicyclic hydrocarbon group in the molecule are preferable, and the alicyclic hydrocarbon group is alicyclic saturated. It is more preferable that it is a hydrocarbon group. This resist composition containing the resin (A) obtained by polymerizing the monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group can produce a resist pattern with higher resolution. The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups (eg, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, etc.) and cycloalkenyl groups (eg, cyclopentenyl group, cyclohexenyl group). , Cycloheptenyl group, cyclooctenyl group, etc.). Examples of polycyclic alicyclic hydrocarbon groups include groups obtained by hydrogenating condensed aromatic hydrocarbon groups (for example, hydronaphthyl groups), bridged cyclic hydrocarbon groups (for example, adamantyl groups, norbornyl groups, etc.) ) And the like. The bridged cyclic hydrocarbon group may have an unsaturated bond therein (for example, a norborneneyl group). Further, a group having a shape in which a bridged ring (for example, a norbornane ring) and a single ring (for example, a cycloheptane ring or a cyclohexane ring) or a polycycle (for example, a decahydronaphthalene ring) are condensed as described below, Or the group of the shape where bridge | crosslinking rings condensed is also contained in an alicyclic hydrocarbon group. Examples of typical alicyclic hydrocarbon groups are shown below (* represents a bond).

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−（ｋ１は１〜７の整数を表す。）で表される基を表す。ここで、−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−は、左側で式（ａ１−１）及び式（ａ１−２）の−ＣＯ−と結合し、右側でアダマンチル基又はシクロへキシル基と結合することを意味する。
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、Ｃ_1-10脂肪族炭化水素基を表す。
ｍ１は０〜１４の整数を表し、ｎ１は０〜１０の整数を表す。 Among the (meth) acrylic monomers having an acid labile group (1) and a C _5-20 alicyclic hydrocarbon group in the molecule, they are represented by the formula (a1-1) or the formula (a1-2). Monomer (a1) [Hereinafter, the monomer (a1) represented by the formula (a1-1) is referred to as “monomer (a1-1)”, and the monomer (a1) represented by the formula (a1-2) is represented by “ Monomer (a1-2) ". ] Is preferable. When manufacturing resin (A), these may be used independently and may use 2 or more types together.

In formula (a1-1) and formula (a1-2),
L ^a1 and L ^a2 each independently represent a group represented by —O— or —O— (CH ₂ ) _k1 —CO—O— (k1 represents an integer of 1 to 7). Here, —O— (CH ₂ ) _k1 —CO—O— is bonded to —CO— of the formula (a1-1) and the formula (a1-2) on the left side, and an adamantyl group or cyclohexyl group on the right side. It means to combine with.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represents a C _1-10 aliphatic hydrocarbon group.
m1 represents an integer of 0 to 14, and n1 represents an integer of 0 to 10.

L ^a1 and L ^a2 are preferably —O— or a group represented by —O— (CH ₂ ) _k1 —CO—O—, wherein k1 is 1 to 4, and more preferably —O— or — O—CH ₂ —CO—O—, particularly preferably —O—.

R ^a4 and R ^a5 are preferably methyl groups. When the aliphatic hydrocarbon group is a chain type (chain hydrocarbon group), the number of carbon atoms of the aliphatic hydrocarbon group of R ^a6 and R ^a7 is preferably 6 or less, and the aliphatic hydrocarbon group Is a cyclic (alicyclic hydrocarbon group), the carbon number thereof is preferably 8 or less, more preferably 6 or less. Examples of the chain aliphatic hydrocarbon group include a methyl group, an ethyl group, a 1-methylethyl group (isopropyl group), a 1,1-dimethylethyl group (tert-butyl group), a 2,2-dimethylethyl group, and propyl. Group, 1-methylpropyl group, 2,2-dimethylpropyl group, 1-ethylpropyl group, butyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-propylbutyl group, pentyl group, 1 -Methylpentyl group, hexyl group, 1,4-dimethylhexyl group, heptyl group, 1-methylheptyl group, octyl group and the like can be mentioned. Examples of the alicyclic hydrocarbon group include a cycloheptyl group, a methylcycloheptyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a norbornyl group, and a methylnorbornyl group.

  m1 is preferably in the range of 0 to 3, more preferably 0 or 1. n1 is preferably in the range of 0 to 3, more preferably 0 or 1.

Examples of the monomer (a1-1) include the following. Among these, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, and 2-isopropyl-2-adamantyl (meth) acrylate are preferable, and “CH ₂ ═C (CH Those having a partial structure of “ ₃ ) —CO—” are more preferable.

Examples of the monomer (a1-2) include the following. Among these, 1-ethyl-1-cyclohexyl (meth) acrylate is preferable, and 1-ethyl-1-cyclohexyl methacrylate is more preferable.

式（ａ１−３）中、
Ｒ^a9は、水素原子、ヒドロキシ基などを有することもできるＣ_1-3脂肪族炭化水素基、カルボキシ基、シアノ基、又はアルコキシカルボニル基（−ＣＯＯＲ^a13）を表す。該アルコキシカルボニル基のＲ^a13は、ヒドロキシ基を有することもできるＣ_1-8脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる−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（Ｒ^a10〜Ｒ^a12）は、それぞれ独立に、ヒドロキシ基などを有することもできるＣ_1-12脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。また、Ｒ^a10及びＲ^a11は互いに結合して、これらが結合する炭素原子とともに環を形成していてもよい。 The monomer (a1-1) and the monomer (a1-2), which are preferable monomers (a1) among the monomers (a1) having the acid labile group (1), have been described above. The other monomer (a1) having (1) will be described. As such a monomer (a1), for example, a monomer having a norbornene ring represented by the formula (a1-3) [hereinafter referred to as “monomer (a1-3)”. ]. The resin (A) having a structural unit derived from the monomer (a1-3) has a bulky structure. Therefore, the resist composition containing the resin (A) can produce a resist pattern with higher resolution. Further, the obtained resist pattern has excellent dry etching resistance.

In formula (a1-3),
R ^a9 represents a C _1-3 aliphatic hydrocarbon group, a carboxy group, a cyano group, or an alkoxycarbonyl group (—COOR ^a13 ) that may have a hydrogen atom, a hydroxy group, or the like. R ^a13 of the alkoxycarbonyl group represents a C _1-8 aliphatic hydrocarbon group which may have a hydroxy group, and —CH ₂ — contained in the aliphatic hydrocarbon group is —O— or —CO—. May be replaced.
R ^a10 , R ^a11 and R ^a12 (R ^{a10 to} R ^a12 ) each independently represent a C _1-12 aliphatic hydrocarbon group which may have a hydroxy group or the like, and are contained in the aliphatic hydrocarbon group —CH ₂ — may be replaced by —O— or —CO—. R ^a10 and R ^a11 may be bonded to each other to form a ring together with the carbon atom to which they are bonded.

Examples of R ^a9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group. ^Examples of R ^a13 include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.

Examples of R ^{a10 to} R ^a12 include a methyl group, an ethyl group, a cyclohexyl group, a methylcyclohexyl group, a hydroxycyclohexyl group, an oxocyclohexyl group, and an adamantyl group. ^Examples of the ring formed by combining R ^a10 and R ^a11 include a cyclohexane ring and an adamantane ring.

  As the monomer (a1-3), for example, 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene-2-carboxylic 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-methyl) Cyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4-oxocyclohexyl) Ethyl and 5-norbornene-2-carboxylic acid 1- (1-adamantyl) -1-methyl Ethyl and the like.

式（２）中、Ｒ^b1は、脂肪族炭化水素基又は芳香族炭化水素基を表す。Ｒ^b2及びＲ^b3は、それぞれ独立に、水素原子、脂肪族炭化水素基又は芳香族炭化水素基を表し、Ｒ^b2及びＲ^b3が互いに結合して、それらが各々結合する炭素原子及び酸素原子とともに環を形成していてもよい。また、Ｒ^b1、Ｒ^b2及びＲ^b3のいずれかが−ＣＨ_２−を含む脂肪族炭化水素基である場合、該脂肪族炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−Ｓ−、−ＣＯ−、−ＳＯ_２−又はアミノ基に置き換わっていてもよい。＊は結合手を表す。 Resin (A) comprises monomer (a1) having an acid labile group represented by the following formula (2) (hereinafter sometimes referred to as “acid labile group (2)”) together with monomer (1). It can also be produced by polymerization.

In formula (2), R ^b1 represents an aliphatic hydrocarbon group or an aromatic hydrocarbon group. R ^b2 and R ^b3 each independently represent a hydrogen atom, an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and R ^b2 and R ^b3 are bonded to each other, together with the carbon atom and oxygen atom to which they are bonded, respectively. A ring may be formed. Also, one of R ^b1, R ^b2 and R ^b3 are -CH ₂ - an aliphatic hydrocarbon group containing a, -CH ₂ contained in the aliphatic hydrocarbon group - is, -O -, - S -, - CO -, - SO 2 - or may be substituted with an amino group. * Represents a bond.

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

［式（ａ１−４）中、
Ｒ¹⁰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Ｃ_1-6アルキル基を表す。
Ｒ¹¹は、それぞれ独立に、ハロゲン原子、ヒドロキシ基、Ｃ_1-6アルキル基、Ｃ_1-6アルコキシ基、Ｃ_2-4アシル基、Ｃ_2-4アシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｌａは０〜４の整数を表す。ｌａが２以上の整数である場合、複数のＲ¹¹はそれぞれ独立である。
Ｒ¹²及びＲ¹³はそれぞれ独立に、置換基を有することもできるＣ_1-12脂肪族炭化水素基又は水素原子を表す。
Ｘ^a2は、置換基を有することもできるＣ_1-17脂肪族炭化水素基又は単結合を表し、該脂肪族炭化水素基に含まれる−ＣＨ_２−は、−ＣＯ−、−Ｏ−、−Ｓ−、−ＳＯ_２−又は−Ｎ（Ｒ^ｃ）−に置き換わっていてもよい。Ｒ^ｃは、水素原子又はＣ_1-6アルキル基を表す。
Ｙ^a3は、置換基を有することもできるＣ_1-18脂肪族炭化水素基又は置換基を有することもできるＣ_6-18芳香族炭化水素基を表す。］ Examples of the monomer having an acid labile group (2) and a carbon-carbon double bond include a monomer (a1-4) represented by the formula (a1-4).

[In the formula (a1-4),
R ¹⁰ represents a hydrogen atom, a halogen atom, or a C _1-6 alkyl group which may have a halogen atom.
R ¹¹ each independently represents a halogen atom, a hydroxy group, a C _1-6 alkyl group, a C _1-6 alkoxy group, a C _2-4 acyl group, a C _2-4 acyloxy group, an acryloyl group or a methacryloyl group.
la represents an integer of 0 to 4. When la is an integer of 2 or more, each of the plurality of R ¹¹ is independent.
R ¹² and R ¹³ each independently represents a C _1-12 aliphatic hydrocarbon group or a hydrogen atom which may have a substituent.
X ^a2 represents a C _1-17 aliphatic hydrocarbon group or a single bond which may have a substituent, and —CH ₂ — contained in the aliphatic hydrocarbon group is —CO—, —O—, — S—, —SO ₂ — or —N (R ^c ) — may be substituted. R ^c represents a hydrogen atom or a C _1-6 alkyl group.
Y ^a3 represents a C _1-18 aliphatic hydrocarbon group which may have a substituent or a C _6-18 aromatic hydrocarbon group which may have a substituent. ]

Examples of the halogen atom for R ¹⁰ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the C _1-6 alkyl group in R ¹⁰ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. It is done. Examples of the C _1-6 alkyl group having a halogen atom include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, and a perfluorosec-butyl group. Perfluoro tert-butyl group, perfluoropentyl group, perfluorohexyl group and the like. Thus, R ¹⁰ is a halogen atom or a C _1-6 alkyl group that may have a halogen atom, and among these, a C _1-4 alkyl group and a hydrogen atom are preferred, and a methyl group, an ethyl group, And a hydrogen atom are more preferable, and a methyl group and a hydrogen atom are particularly preferable.

Examples of the C _1-6 alkoxy group in R ¹¹ 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 n. -A hexoxy group etc. are mentioned. Among these, a C _1-4 alkoxy group is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is particularly preferable.
Examples of the C _2-4 acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the C _2-4 acyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
Examples of the C _1-12 hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, Examples include 2-ethylhexyl group, cyclohexyl group, adamantyl group, 2-alkyl-2-adamantyl group, 1- (1-adamantyl) -1-alkyl group, and isobornyl group.

Ｃ_6-18芳香族炭化水素基としては、例えば、フェニル基、ナフチル基、アントラニル基、ｐ−メチルフェニル基、ｐ−ｔｅｒｔ−ブチルフェニル基及びｐ−アダマンチルフェニル基などが挙げられる。 The C _1-12 aliphatic hydrocarbon group in R ¹² and R ¹³ may be a chain hydrocarbon group or an alicyclic hydrocarbon group. Examples of chain hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, and heptyl. Group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like.
Examples of the alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, a 1-adamantyl group, and a 2-adamantyl group. , Isobornyl groups, groups shown below, and the like.

Examples of the C _6-18 aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthranyl group, a p-methylphenyl group, a p-tert-butylphenyl group, and a p-adamantylphenyl group.

As a monomer (a1-4), the following monomers are mentioned, for example.

<Acid stable monomer>
Resin (A) is a monomer that does not have acid labile groups such as acid labile group (1) and acid labile group (2) in addition to monomer (1) and monomer (a1) (hereinafter referred to as “acid stable monomer”). ") Is preferred. When manufacturing such resin (A), this acid stable monomer may be used individually by 1 type, and may use 2 or more types together.
When the resin (A) is a copolymer obtained from the monomer (1), the monomer (a1) and the acid-stable monomer, the monomer (a1) is added to 100 mol% of all the structural units of the resin (A). The content ratio of the derived structural unit is 1 to 100 mol%, preferably 5 to 80 mol%, more preferably 10 to 80 mol%, still more preferably 10 to 60 mol%, still more preferably 20 to 60 mol%. . When the structural unit derived from the monomer (a1) includes a structural unit derived from the monomer (a1-1), the monomer (a1- The structural unit derived from 1) is preferably 15 mol% or more. When the content ratio of the monomer having an adamantyl group such as the monomer (a1-1) is increased, the dry etching resistance of the resist pattern produced from the resist composition containing the resin (A) is improved.

  As the acid stable monomer, those having a hydroxy group or a lactone ring are preferable. Derived from an acid-stable monomer having a hydroxy group (hereinafter sometimes referred to as “acid-stable monomer (a2)”) or an acid-stable monomer having a lactone ring (hereinafter sometimes referred to as “acid-stable monomer (a3)”) In addition to being able to produce a resist pattern with higher resolution, the present resist composition containing the resin (A) having a structural unit can be used to produce a resist pattern, and when the resist composition is applied to a substrate, a coating film formed on the substrate, or The composition layer obtained from the coating film easily exhibits excellent adhesion with the substrate. In addition, the manufacturing method of the resist pattern using this resist composition is mentioned later.

<Acid stable monomer (a2)>
When the acid-stable monomer (a2) is used in the production of the resin (A), a suitable acid-stable monomer (depending on the type of exposure source when producing a resist pattern from the resist composition containing the resin (A), a2) can be used. That is, when this resist composition is used for KrF excimer laser exposure (wavelength: 248 nm), high energy beam exposure such as electron beam or EUV light, the acid stable monomer having a phenolic hydroxyl group is used as the acid stable monomer (a2). It is preferable to use the monomer (a2-0) [for example, hydroxystyrenes] for the production of the resin (A). When short-wavelength ArF excimer laser exposure (wavelength: 193 nm) is used, it is preferable to use an acid-stable monomer represented by formula (a2-1) as the acid-stable monomer (a2) in the production of the resin (A). . As described above, the acid-stable monomer (a2) used for the production of the resin (A) can be preferably selected depending on the exposure source used for producing the resist pattern. The acid-stable monomer (a2) The resin (A) may be produced using only one kind of monomer suitable for the kind of the resin, or the resin (A) may be produced using two or more kinds of suitable monomers for the kind of the exposure source. Alternatively, the resin (A) may be produced by using two or more types in combination of a suitable monomer according to the type of the exposure source and the other acid stable monomer (a2).

［式（ａ２−０）中、
Ｒ^８は、水素原子、ハロゲン原子又はハロゲン原子を有することもできるＣ_1-6アルキル基を表す。
Ｒ^９は、ハロゲン原子、水酸基、Ｃ_1-6アルキル基、Ｃ_1-6アルコキシ基、Ｃ_2-4アシル基、Ｃ_2-4アシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上である場合、複数のＲ^９はそれぞれ独立である。］ Examples of the acid-stable monomer having a phenolic hydroxyl group include styrene monomers such as p- or m-hydroxystyrene represented by the formula (a2-0) (hereinafter referred to as “acid-stable monomer (a2-0)”). Can be mentioned. In addition, this formula (a2-0) is shown in a form in which the phenolic hydroxyl group is not protected with an appropriate protecting group.

[In the formula (a2-0),
R ⁸ represents a hydrogen atom, a halogen atom, or a C _1-6 alkyl group that may have a halogen atom.
R ⁹ represents a halogen atom, a hydroxyl group, a C _1-6 alkyl group, a C _1-6 alkoxy group, a C _2-4 acyl group, a C _2-4 acyloxy group, an acryloyl group or a methacryloyl group.
ma represents an integer of 0 to 4. When ma is 2 or more, the plurality of R ⁹ are each independent. ]

Specific examples of the halogen atom and the C _1-6 alkyl group which may have a halogen atom in R ⁸ are the same as those exemplified as R ^{10 in the} formula (a1-4). Among these, a C _1-4 alkyl group is preferable, a methyl group and an ethyl group are more preferable, and a methyl group is particularly preferable.

Specific examples of the C _1-6 alkoxy group, the C _2-4 acyl group, and the C _2-4 acyloxy group in R ⁹ are the same as those exemplified as R ^{11 in the} formula (a1-4). As the C _1-6 alkoxy group, a C _1-4 alkoxy group is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is particularly preferable.

  When the resin (A) having a structural unit derived from such an acid stable monomer (a2-0) is produced, the phenolic hydroxyl group in the acid stable monomer (a2-0) is protected with an appropriate protecting group. Monomers (monomers having a protected phenolic hydroxyl group) can also be used. As the protecting group here, for example, an acetyl group is preferred. A phenolic hydroxyl group protected with an acetyl group is deprotected by contact with an acid, so that it is easily stabilized from a structural unit derived from a monomer having a phenolic hydroxyl group protected with an acetyl group. The same structural unit derived from the monomer (a2-0) can be formed. However, since the resin (A) has a structural unit derived from the monomer (a1) having an acid labile group as described above, the resin (A) is derived from a monomer in which the phenolic hydroxyl group is protected with an appropriate protecting group. When deprotecting the structural unit, it is necessary to carry out the deprotection so that the acid labile group is not significantly impaired.

As an acid stable monomer (a2-0), the following are mentioned, for example. In the following examples, the phenolic hydroxyl group is not protected by an appropriate protecting group.

  Of the above acid-stable monomers (a2-0), 4-hydroxystyrene or 4-hydroxy-α-methylstyrene is particularly preferable.

式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−（ｋ２は１〜７の整数を表す。）で表される基を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 As the acid stable monomer (a2) having a hydroxy group, an acid stable monomer (a2) having a hydroxyadamantyl group in the molecule is particularly preferred. Such an acid stable monomer (a2) is represented, for example, by the formula (a2-1) (hereinafter referred to as “acid stable monomer (a2-1)”).

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

L ^a3 is preferably a group represented by —O— and —O— (CH ₂ ) _k2 —CO—O—, wherein k2 is an integer of 1 to 4, and 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 in the range of 0 to 3, more preferably 0 or 1.

Examples of the acid stable monomer (a2-1) include the following. Among these, 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl (meth) acrylate and (meth) acrylic acid 1- (3,5-dihydroxy-1-adamantyloxycarbonyl) Methyl is preferred, 3-hydroxy-1-adamantyl (meth) acrylate and 3,5-dihydroxy-1-adamantyl (meth) acrylate are more preferred, 3-hydroxy-1-adamantyl methacrylate and 3,5-dihydroxy-1- More preferred is adamantyl methacrylate.

<Acid stable monomer (a3)>
The acid stable monomer (a3) is preferably a monomer having a lactone ring group as in the monomer (1), for example. The lactone ring may be a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or may be a condensed ring of a monocyclic lactone ring and another ring. Among these lactone rings, the lactone ring of the acid-stable monomer (a3) is preferably a γ-butyrolactone ring or a condensed ring of a γ-butyrolactone ring and another ring.

The acid stable monomer (a3) is preferably one represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3). When manufacturing resin (A), these 1 type may be used independently and 2 or more types may be used together.

In formula (a3-1), formula (a3-2) and formula (a3-3) [formula (a3-1) to formula (a3-3)],
L ^a4 , L ^a5 and L ^a6 (L ^{a4 to} L ^a6 ) are each independently —O— or —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). Represents a group represented by
R ^a18 , R ^a19 and R ^a20 (R ^{a18 to} R ^a20 ) each independently represent a hydrogen atom or a methyl group.
R ^a21 represents a C _1-4 aliphatic hydrocarbon group, and p1 represents an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 are each independent.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group or a C _1-4 aliphatic hydrocarbon group, and q1 and r1 each independently represent an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 are each independent, and when r1 is 2 or more, the plurality of R ^a23 are each independent.

Specific examples of L ^{a4 to} L ^a6 are the same as those exemplified for L ^a3 in the formula (a2-1). L ^{a4 to} L ^a6 each independently represent —O— and —O— (CH ₂ ) _k3 —CO—O—, wherein k3 is an integer of 1 to 4, more preferably —O—. However, this —O— (CH ₂ ) _k3 —CO—O— is bonded to —CO— of the formula (a3-1) to (a3-3) on the left side and bonded to the lactone ring on the right side. means.
R ^{a18 to} R ^a20 are preferably methyl groups.
R ^a21 is preferably a methyl group.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group. p1, q1 and r1 are each independently preferably in the range of 0 to 2, more preferably 0 or 1.

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

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

Examples of the acid stable monomer (a3-3) having a condensed ring of γ-butyrolactone ring and cyclohexane ring include the following.

Among acid-stable monomers (a3) having a lactone ring, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yl, (meth) acrylic Acid tetrahydro-2-oxo-3-furyl, 2- (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yloxy) -2-oxoethyl (meth) acrylate Are preferred, and those in the form of methacrylate are more preferred.

のいずれかで示される基が（メタ）アクロイル基である場合（前記式（ａ３−１）におけるＬ^ａ４、前記式（ａ３−２）におけるＬ^ａ５、又は前記式（ａ３−３）におけるＬ^ａ６が−Ｏ−である場合）、この（メタ）アクロイル基に結合する炭素原子が３級炭素原子であるとき、これら式（ａ３−１）、式（ａ３−２）又は式（ａ３−３）で表されるモノマーは、モノマー（ａ１）と同様に、酸不安定基（１）を有するものとなる。このような酸安定モノマー（ａ３）の例外を挙げる。なお、このようなモノマーは、樹脂（Ａ）を製造する際に、酸不安定基を有するモノマーとして用いることができる。 <Exception of acid stable monomer (a3)>
In the formula (a3-1), the formula (a3-2) or the formula (a3-3),

When the group represented by any one of (a) is a (meth) acryloyl group (L ^a4 in the formula (a3-1), L ^a5 in the formula (a3-2), or L ^a6 in the formula (a3-3) Is -O-), when the carbon atom bonded to the (meth) acryloyl group is a tertiary carbon atom, these formula (a3-1), formula (a3-2) or formula (a3-3) In the same manner as the monomer (a1), the monomer represented by the formula (1) has an acid labile group (1). An exception to such acid stable monomers (a3) is given. In addition, such a monomer can be used as a monomer having an acid labile group when the resin (A) is produced.

The following monomers can be illustrated as an exception of an acid stable monomer (a3-1).

The following monomers can be illustrated as an exception of an acid stable monomer (a3-2).

The following monomers can be illustrated as an exception of an acid stable monomer (a3-3).

<Other acid stable monomers>
As described above, the preferred acid stable monomer (a3) and acid stable monomer (a4) have been described as the acid stable monomer. Stable monomer (a4) ”). Hereinafter, the acid stable monomer (a4) will be described.
Examples of the acid stable monomer (a4) include maleic anhydride represented by formula (a4-1), itaconic anhydride represented by formula (a4-2), and formula (a4-3). And an acid-stable monomer having a norbornene ring (hereinafter referred to as “acid-stable monomer (a4-3)”).

In formula (a4-3),
R ^a25 and R ^a26 each independently represent a C _1-3 aliphatic hydrocarbon group, a cyano group, a carboxy group, or an alkoxycarbonyl group (-COOR ^a27 , R ^a27 can be a hydrogen atom, a hydroxy group, etc. , C _1-36 represents an aliphatic hydrocarbon group, and —CH ₂ — contained in the aliphatic hydrocarbon group may be replaced by —O— or —CO—, provided that —COOR ^a27 is an acid labile group. (Ie, R ^a27 does not include those in which a tertiary carbon atom is bonded to —O—)), or R ^a25 and R ^a26 are bonded to each other to form —CO—O—CO. -Is formed.

^Examples of the aliphatic hydrocarbon group that may have a hydroxy group in R ^a25 and R ^a26 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
^When the aliphatic hydrocarbon group for R ^a27 is a chained aliphatic hydrocarbon group, the carbon number thereof is preferably 1 to 8, more preferably 1 to 6, and a cyclic aliphatic hydrocarbon group. In this case, the carbon number is preferably 4 to 36, more preferably 4 to 12. ^Examples of R ^a27 include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.

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

  A preferred resin (A) is a copolymer obtained by polymerizing the monomer (1), at least one monomer (a1), the acid stable monomer (a2) and / or the acid stable monomer (a3). The monomer (a1) is more preferably the monomer (a1-1) or the monomer (a1) containing the monomer (a1-2), and more preferably the monomer (a1) containing the monomer (a1-1). is there. The acid stable monomer (a2) is more preferably one having a hydroxyadamantyl group, and still more preferably an acid stable monomer (a2) including the acid stable monomer (a2-1). The acid stable monomer (a3) is more preferably an acid stable monomer (a3-1) having a γ-butyrolactone ring or an acid stable monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring. At least one. Resin (A) can be manufactured by a well-known polymerization method (for example, radical polymerization method).

  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). In addition, this weight average molecular weight is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis, and the detailed analysis conditions of this analysis are explained in full detail in the Example of this application.

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

  Examples of the acid generator (B) include not only an acid generator (particularly a photoacid generator) used in the resist field, but also a photoinitiator for photocationic polymerization, a photodecolorant for dyes, or a photochromic agent. Known compounds that generate an acid by radiation (light) and mixtures thereof can also be used as appropriate. For example, JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A 62-153853, Acid by radiation described in Japanese Utility Model Publication No. 63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. Can be used.

The acid generator (B) is preferably a fluorine-containing acid generator, more preferably an acid generator represented by the formula (B1).

In formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C _1-6 perfluoroalkyl group. Examples of the perfluoroalkyl group 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. Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Y represents a C _1-36 aliphatic hydrocarbon group, and —CH ₂ — contained in the aliphatic hydrocarbon group may be replaced with —O— or —CO—. Here, a representative example of a group in which —CH ₂ — contained in a cyclic aliphatic hydrocarbon group is replaced with —O— or —CO— is shown. For example, a cyclic ether group (a group in which one or two of —CH ₂ — contained in a cyclic aliphatic hydrocarbon group is replaced by —O—), a cyclic ketone group (included in a cyclic aliphatic hydrocarbon group) -CH ₂ - 1 or 2 but, -CH ₂ included in the group) and lactone Hajime Tamaki (cyclic aliphatic hydrocarbon group replaced with -CO- - adjacent one of the two -CH ₂ - is, And groups in which -O- and -CO- are substituted, respectively.

Among the aliphatic hydrocarbon groups of Y, the chain aliphatic hydrocarbon group includes methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl. Group, t-butyl group, n-pentyl group, i-pentyl group, t-pentyl group, neopentyl group, 1-methylbutyl group, 2-methylbutyl group, 1,2-dimethylpropyl group, 1-ethylpropyl group, n C _1-6 alkyl groups such as -hexyl group, 1-methylpentyl group and n-heptyl group are preferred.

Among the saturated cyclic hydrocarbon groups of Y, examples of the cyclic aliphatic hydrocarbon group (alicyclic hydrocarbon group) include groups represented by formulas (Y1) to (Y26).

  Among these, a preferred alicyclic hydrocarbon group is a group represented by any one of formulas (Y1) to (Y19), and more preferably formula (Y11), formula (Y14), and formula (Y15). Or it is group represented by a formula (Y19), More preferably, it is group represented by a formula (Y11) or a formula (Y14).

The aliphatic hydrocarbon group for Y may have a substituent. Examples of the substituent include a halogen atom (excluding a fluorine atom), a hydroxy group, a C _1-12 alkoxy group, a C _6-18 aromatic hydrocarbon group, a C _7-21 aralkyl group, and a C _2-4 acyl group. , Glycidyloxy group, or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is a C _1-16 aliphatic hydrocarbon group, a C _3-16 saturated cyclic hydrocarbon group or C _{6 -18} represents an aromatic hydrocarbon group, j2 represents an integer of 0 to 4.) and the like.
Examples of the C _1-12 alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group.
Examples of the C _6-18 aromatic hydrocarbon group include a phenyl group, a naphthyl group, and an anthranyl group, and further include a p-methylphenyl group, a p-tert-butylphenyl group, and a p-methyl group having a substituent on the aromatic ring. An adamantylphenyl group and the like can also be mentioned.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, and naphthylethyl group. These aralkyl groups can also have a substituent on the aromatic ring.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group. When the aliphatic hydrocarbon group for Y has a plurality of substituents, the plurality of substituents are independent of each other.

Specific examples of Y are given below. Examples of the alicyclic hydrocarbon group having an alkyl group include the following.

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

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

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

  Y is preferably an adamantyl group that can have a substituent or an oxoadamantyl group that can also have a substituent, and more preferably an unsubstituted adamantyl group or an unsubstituted oxoadamantyl group.

L ^b1 represents a single bond or a divalent C _1-17 aliphatic hydrocarbon group which may have a substituent, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group. As the aliphatic hydrocarbon group, a linear alkanediyl group (for example, methylene group, ethylene group, propane-1,3-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 and heptadecane -1,17-diyl group, etc.), branched chain alkanediyl groups (for example, the straight chain alkanediyl group, C _1-4 alkyl group (for example, methyl group, ethyl group, propyl group, isopyl group) Propyl group, butyl group, sec-butyl group and tert-butyl group) are bonded to each other and the total carbon number thereof is 17 or less) and a cyclic aliphatic hydrocarbon group [cycloalkanediyl group (for example, cyclohexanediyl group) And a divalent bridged cyclic hydrocarbon group (for example, an adamantanediyl group)], and a combination of two or more of these groups may be used.

The divalent aliphatic hydrocarbon group for L ^b1 may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a carboxy group, a C _6-18 aromatic hydrocarbon group, a C _7-21 aralkyl group, a C _2-4 acyl group, and a glycidyloxy group.

In addition, —CH ₂ — contained in the divalent aliphatic hydrocarbon group of L ^b1 may be replaced with —O— or —CO—. L ^b1 is preferably any one of formula (b1-1) to formula (b1-6), more preferably any of formula (b1-1) to formula (b1-4), and even more preferably formula (b1). -1) or the formula (b1-2). Note the formula (b1-1) ~ formula (b1-6) has its left and right are described in accordance with the formula (B1), the left ^{C (Q 1) (Q 2} ) - bound to, the right side - Combine with Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).

In formula (b1-1), L ^b2 represents a single bond or a C _1-15 alkanediyl group.
In formula (b1-2), L ^b3 represents a single bond or a C _1-12 alkanediyl group, and L ^b4 represents a C _1-13 alkanediyl group. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
In formula (b1-3), L ^b5 represents a C _1-15 alkanediyl group.
In formula (b1-4), L ^b6 and L ^b7 each independently represent a C _1-15 alkanediyl group. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
In formula (b1-5), L ^b8 represents a C _1-14 alkanediyl group.
In formula (b1-6), L ^b9 and L ^b10 each independently represent a C _1-11 alkanediyl group. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 12.
Among these, 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.

Examples of the divalent group represented by the formula (b1-1) include the following.

Examples of the divalent group represented by the formula (b1-2) include the following.

Examples of the divalent group represented by the formula (b1-3) include the following.

Examples of the divalent group represented by the formula (b1-4) include the following.

Examples of the divalent group represented by the formula (b1-5) include the following.

Examples of the divalent group represented by the formula (b1-6) include the following.

The sulfonate anion preferably has a divalent group represented by the formula (b1-1), more preferably one represented by the formula (b1-1-1) to the formula (b1-1-9). .

In formula (b1-1-1) to formula (b1-1-9), Q ¹ , Q ² and L ^b2 have the same meaning as in formula (B1). R ^b2 and R ^b3 each independently represent a C _1-4 aliphatic hydrocarbon group (preferably a methyl group).

Next, specific sulfonate anions are exemplified. First, Y is an aliphatic hydrocarbon group having no substituent or an alicyclic hydrocarbon group having an alkyl group, and L ^b1 is a divalent group represented by the formula (b1-1) The sulfonate anion containing is illustrated.

Y is a cycloaliphatic hydrocarbon group having a — (CH ₂ ) _j2 —O—CO—R ^b1 group, and L ^b1 is a divalent group represented by the formula (b1-1) Examples of the anion include the following.

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

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

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

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

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

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group that can also have an alkyl group, and L ^b1 is a sulfonate anion that is a divalent group represented by the formula (b1-2) include: The following are mentioned.

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

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

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

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

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

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

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group that may have an alkyl group, and L ^b1 is a divalent group represented by the formula (b1-3) include the following. Can be mentioned.

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

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

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

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

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

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

Among the examples of the sulfonate anion described above, a sulfonate anion in which L ^b1 is a divalent group represented by the formula (b1-1) is preferable, and the following sulfonate anions are more preferable.

  Next, the cation contained in the acid generator (B) will be described. As the cation, an organic cation is preferable, and among them, an onium cation is preferable. Examples of the onium cation include a sulfonium cation, an iodonium cation, an ammonium cation, a benzothiazolium cation, and a phosphonium cation. Among these, a sulfonium cation and an iodonium cation are preferable, and an arylsulfonium cation is more preferable.

式（ｂ２−１）中、
Ｒ^b4〜Ｒ^b6は、それぞれ独立に、Ｃ_1-36脂肪族炭化水素基又はＣ_6-18芳香族炭化水素基を表す。該脂肪族炭化水素基のうち、鎖状の脂肪族炭化水素基は、ヒドロキシ基、Ｃ_1-12アルコキシ基或いはＣ_6-18芳香族炭化水素基（該芳香族炭化水素基は、ハロゲン原子、ヒドロキシ基、Ｃ_1-36脂肪族炭化水素基、Ｃ_3-36飽和環状炭化水素基又はＣ_1-12アルコキシ基を有することもできる。）を有することもできる。該脂肪族炭化水素基のうち、脂環式炭化水素基は、ハロゲン原子、Ｃ_2-4アシル基、又はグリシジルオキシ基を有することもできる。 The organic cation (Z ⁺ ) in the formula (B1) is preferably represented by any one of the formulas (b2-1) to (b2-4). Hereinafter, these organic cations may be referred to as “cation (b2-1)” to “cation (b2-4)” depending on the formula number.

In formula (b2-1),
R ^{b4 to} R ^b6 each independently represents a C _1-36 aliphatic hydrocarbon group or a C _6-18 aromatic hydrocarbon group. Among the aliphatic hydrocarbon groups, a chain aliphatic hydrocarbon group is a hydroxy group, a C _1-12 alkoxy group or a C _6-18 aromatic hydrocarbon group (the aromatic hydrocarbon group is a halogen atom, It may also have a hydroxy group, a C _1-36 aliphatic hydrocarbon group, a C _3-36 saturated cyclic hydrocarbon group or a C _1-12 alkoxy group. Among the aliphatic hydrocarbon groups, the alicyclic hydrocarbon group may have a halogen atom, a C _2-4 acyl group, or a glycidyloxy group.

In formula (b2-2),
R ^b7 and R ^b8 each independently represent a hydroxy group, a C _1-12 aliphatic hydrocarbon group or a C _1-12 alkoxy group.
m2 and n2 each independently represent an integer of 0 to 5.

In formula (b2-3),
R ^b9 and R ^b10 each independently represent a C _1-36 aliphatic hydrocarbon group.
R ^b11 represents a hydrogen atom, a C _1-36 aliphatic hydrocarbon group or a C _6-18 aromatic hydrocarbon group.
When the aliphatic hydrocarbon group of R ^{b9 to} R ^b11 is a chain aliphatic hydrocarbon group, the carbon number is preferably 1 to 12, and when the aliphatic hydrocarbon group is an alicyclic hydrocarbon group, the carbon number is , Preferably 3 to 36, more preferably 4 to 12.
R ^b12 represents a C _1-18 aliphatic hydrocarbon group or a C _6-18 aromatic hydrocarbon group. The aromatic hydrocarbon group may have a C _1-18 aliphatic hydrocarbon group, a C _1-12 alkoxy group, or a C _2-13 alkylcarbonyloxy group.
The combination of R ^b9 and R ^b10 and the combination of R ^b11 and R ^b12 are independently bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring). In these rings, —CH ₂ — may be replaced by —O—, —S— or —CO—.

In formula (b2-4),
R ^{b13 to} R ^b18 each independently represents a hydroxy group, a C _1-12 aliphatic hydrocarbon group, or a C _1-12 alkoxy group.
L ^b11 represents -S- or -O-.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5, q2 and r2 each independently represent an integer of 0 to 4, and u2 represents 0 or 1.
When o2 is 2 or more, each of the plurality of R ^b13 is independent. When p2 is 2 or more, each of the plurality of R ^b14 is independent. When s2 is 2 or more, each of the plurality of R ^b15 is When independent and t2 is 2 or more, the plurality of R ^b18 are independent of each other.

Next, preferable examples of the substituents (R ^{b4 to} R ^b18 ) included in the formulas (b2-1) to (b2-4) are given. Of the aliphatic hydrocarbon groups, the chain aliphatic hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, and pentyl groups. , A hexyl group, an octyl group, and a 2-ethylhexyl group are preferred. Among the aliphatic hydrocarbon groups, the alicyclic hydrocarbon group is cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyl-2-adamantyl group, 1- (1- An alicyclic saturated hydrocarbon group such as an adamantyl) -1-alkyl group and an isobornyl group is preferred. Preferred aromatic hydrocarbon groups are phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, biphenylyl group, and naphthyl. It is a group. Examples of the aliphatic hydrocarbon group (aralkyl group) having an aromatic hydrocarbon group include a benzyl group. Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, n-hexoxy, heptoxy, octoxy Group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group and the like. 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.

式（ｂ２−１−１）中、Ｒ^b19〜Ｒ^b21は、それぞれ独立に、ハロゲン原子、ヒドロキシ基、Ｃ_1-36脂肪族炭化水素基又はＣ_1-12アルコキシ基を表す。前記脂肪族炭化水素基が鎖状の脂肪族炭化水素基である場合、その炭素数は、好ましくは１〜１２であり、脂環式炭化水素基である場合、その炭素数は、好ましくは４〜３６である。前記鎖状の脂肪族炭化水素基は、ヒドロキシ基、Ｃ_1-12アルコキシ基又はＣ_6-18芳香族炭化水素基で置換されていてもよく、前記脂環式炭化水素基は、ハロゲン原子、Ｃ_2-4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、ｗ２及びｘ２は、それぞれ独立に０〜５の整数（好ましくは０又は１）を表す。ｖ２が２以上のとき、複数のＲ^b19はそれぞれ独立であり、ｗ２が２以上のとき、複数のＲ^b20はそれぞれ独立であり、ｘ２が２以上のとき、複数のＲ^b21はそれぞれ独立である。 Among cation (b2-1) to cation (b2-4), cation (b2-1) is preferable, cation (b2-1) represented by formula (b2-1-1) is more preferable, and triphenylsulfonium. A cation (v2 = w2 = x2 = 0 in the formula (b2-1-1) is more preferable.

In formula (b2-1-1), R ^{b19 to} R ^b21 each independently represent a halogen atom, a hydroxy group, a C _1-36 aliphatic hydrocarbon group, or a C _1-12 alkoxy group. When the aliphatic hydrocarbon group is a chain-like aliphatic hydrocarbon group, the carbon number is preferably 1 to 12, and when the aliphatic hydrocarbon group is an alicyclic hydrocarbon group, the carbon number is preferably 4 ~ 36. The chain aliphatic hydrocarbon group may be substituted with a hydroxy group, a C _1-12 alkoxy group or a C _6-18 aromatic hydrocarbon group, and the alicyclic hydrocarbon group includes a halogen atom, It may be substituted with a C _2-4 acyl group or a glycidyloxy group.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1). When v2 is 2 or more, each of the plurality of R ^b19 is independent. When w2 is 2 or more, each of the plurality of R ^b20 is independent. When x2 is 2 or more, each of the plurality of R ^b21 is independent. .

R ^{b19 to} R ^b21 in formula (b2-1-1) are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, a C _1-12 alkyl group, or a C _1-12 alkoxy group. And v2 to x2 each independently represents an integer of 0 to 5 (preferably 0 or 1).

Next, specific cations contained in the acid generator (B) are exemplified. First, specific examples of the cation (b2-1-1) include the following.

Specific examples of the cation (b2-2) include the following.

Specific examples of the cation (b2-3) include the following.

Specific examples of the cation (b2-4) include the following.

  The sulfonate anion and the organic cation in the acid generator (B1) have been described above. However, the acid generator (B1) can arbitrarily combine these sulfonate anion and organic cation.

  Preferred acid generators (B1) are those represented by formulas (B1-1) to (B1-17), and among these, acid generators (B1-1) and (B1) containing a triphenylsulfonium cation. -2), (B1-6), (B1-11), (B1-12), (B1-13) and (B1-14) are more preferred.

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition may contain a basic compound (C).

The basic compound (C) is preferably a basic nitrogen-containing organic compound (for example, an amine). The amine may be an aliphatic amine or an aromatic amine. As the aliphatic amine, any of primary amine, secondary amine and tertiary amine can be used. The aromatic amine may be any of an amino group bonded to an aromatic ring such as aniline and a heteroaromatic amine such as pyridine. Preferable basic compound (C) includes an aromatic amine represented by the formula (C2), particularly an aniline represented by the formula (C2-1).

In formula (C2),
Ar ^c1 represents an aromatic hydrocarbon group. R ^c5 and R ^c6 each independently represents a hydrogen atom, an aliphatic hydrocarbon group (preferably an alkyl group or a cycloalkyl group) or an aromatic hydrocarbon group. However, the hydrogen atom of the aliphatic hydrocarbon group or the aromatic hydrocarbon group may be substituted with a hydroxy group, an amino group, or a C _1-6 alkoxy group, and the amino group is a C _1-4 alkyl group. It can also have further groups. The aliphatic hydrocarbon group preferably has about 1 to 10 carbon atoms, and the aromatic hydrocarbon group preferably has about 6 to 10 carbon atoms.

In formula (C2-1),
R ^c5 and R ^c6 are the same as described above.
R ^c7 represents an aliphatic hydrocarbon group (preferably an alkyl group or a cycloalkyl group), an alkoxy group, or an aromatic hydrocarbon group. However, the aliphatic hydrocarbon group, the alkoxy group, and the aromatic hydrocarbon group may have the substituent described in the formula (C2). m3 represents an integer of 0 to 3. When m3 is 2 or more, the plurality of R ^c7 are each independent. The preferred number of carbon atoms of the aliphatic hydrocarbon group and aromatic hydrocarbon group of R ^c7 is independently in are the same as those of the formula (C2), the carbon number of the alkoxy group R ^c7 is independently in, preferably about 1-6.

  Examples of the aromatic amine (C2) include 1-naphthylamine and 2-naphthylamine. Examples of aniline (C2-1) include aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine and the like. Of these, diisopropylaniline (particularly 2,6-diisopropylaniline) is preferable.

Moreover, as a basic compound (C), the compound represented by Formula (C3)-Formula (C11) is mentioned.

R ^c8 in formula (C3) represents any of the groups described for R ^c7 in formula (C2). R ^c9 , R ^c10 , R ^{c11 to} R ^c14 , R ^{c16 to} R ^c19 and R ^c22 bonded to the nitrogen atom in formula (C3) to formula (C8) are each independently R ^{c5 in} formula (C2) and It represents one of the groups described for R ^c6 . R ^c20 , R ^c21 and R ^{c23 to} R ^c28 bonded to the aromatic carbon in formula (C7) to formula (C11) are each independently any group described for R ^c7 in formula (C2-1) Represents. O3 to u3 in Formula (C7) and Formula (C9) to Formula (C11) each independently represents an integer of 0 to 3. When o3 is 2 or more, each of the plurality of R ^c20 is independent. When p3 is 2 or more, each of the plurality of R ^c21 is independent. When q3 is 2 or more, each of the plurality of R ^c24 is When r3 is 2 or more, the plurality of R ^c25s are independent, and when s3 is 2 or more, the plurality of R ^c26s are independent, and when t3 is 2 or more, R ^c27 is independent, and when ^u3 is 2 or more, a plurality of R ^c28 are independent.

R ^c15 in the formula (C6) represents an aliphatic hydrocarbon group or an alkanoyl group, and n3 represents an integer of 0 to 8. When n3 is 2 or more, the plurality of R ^c15 are independent of each other. The carbon number of the aliphatic hydrocarbon group for R ^c15 is preferably about 1 to 6, and the carbon number of the alkanoyl group for R ^c15 is preferably about 2 to 6.

L ^c1 and L ^{c2 in} formula (C7) and formula (C10) are each independently a divalent aliphatic hydrocarbon group (preferably an alkanediyl group), —CO—, —C (═NH) —, — C (= NR ^c3 ) —, —S—, —S—S—, or a combination thereof is represented. The divalent aliphatic hydrocarbon group preferably has about 2 to 6 carbon atoms. R ^c3 represents a C _1-4 alkyl group.

  Examples of the compound (C3) include hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, Tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctyl Amine, methyl dinonyl amine, methyl didecyl amine, ethyl dibutyl amine, ethyl dipentyl amine, ethyl di Silamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylene Examples include diamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, and 4,4′-diamino-3,3′-diethyldiphenylmethane.

Examples of the compound (C4) include piperazine.
Examples of the compound (C5) include morpholine.
Examples of the compound (C6) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound (C7) include 2,2′-methylenebisaniline.

Examples of the compound (C8) include imidazole and 4-methylimidazole.
Examples of the compound (C9) include pyridine and 4-methylpyridine.
Examples of the compound (C10) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, and 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, Examples include 4'-dipyridyl disulfide, 2,2'-dipyridylamine, and 2,2'-dipicolylamine.
Examples of the compound (C11) include bipyridine.

<Solvent (hereinafter sometimes referred to as “solvent (E)”)>
The resist composition contains a solvent (E). This solvent (E) has good coating properties when the resist composition is applied on a substrate in the production of a resist pattern, which will be described later, and the types and amounts of the resin (A) and the acid generator (B). From the point that it becomes, it is possible to select the optimum one as appropriate.

  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 contains a resin (A), an acid generator (B), a solvent (E), and other components (F) other than the basic compound (C) used as necessary, if necessary. There are no particular limitations on the other component (F) that can be used, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes, 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 basic compound (C) and the solvent (E). Furthermore, other components (F) may be mixed as necessary. In such mixing, the mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature range from the range of 10-40 degreeC according to the kind etc. of resin (A) to be used, the solubility with respect to solvent (E), such as resin (A). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.

Next, the preferable content of the resin (A), the acid generator (B), the solvent (E), and the basic compound (C) used as necessary in the resist composition will be described.
As described above, the content of the solvent (E) can be appropriately adjusted according to the type of the resin (A), but is preferably 90% by mass or more based on the total mass of the resist composition. The present resist composition containing the solvent (E) in such a content ratio is suitable for producing a thin film resist capable of forming a composition layer having a thickness of about 30 to 300 nm, for example, in a method for producing a resist pattern described later. ing. The content ratio of the solvent (E) is 90% by mass or more (preferably 92% by mass or more, more preferably 94% by mass or more) and 99.9% by mass or less (preferably 99% by mass) with respect to the total mass of the resist composition. % Or less) is preferred. The content of the solvent (E) can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  A preferable range of the content ratio of the resin (A) to the resist composition is selected with respect to the total mass of the solid content of the resist composition. Specifically, the content ratio of the resin (A) with respect to the total mass of the solid content is preferably 80% by mass or more. In addition, solid content here means what remove | excluded the solvent (E) from this resist composition.

  A preferable range of the content ratio of the acid generator (B) to the resist composition is selected with respect to the total mass of the resin (A) contained in the resist composition. Specifically, the acid generator (B) is preferably 1 part by mass or more and more preferably 3 parts by mass or more with respect to 100 parts by mass of the resin (A). The acid generator (B) is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, relative to 100 parts by mass of the resin (A).

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

  The suitable content of each of the resin (A), the acid generator (B), and the basic compound (C) used as necessary is also controlled by the amount used in preparing the resist composition. Is possible. After the present resist composition is prepared, the present resist composition can be obtained by subjecting it to a known analysis means such as gas chromatography or liquid chromatography.

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

  Thus, after mixing resin (A), acid generator (B) and solvent (E), and each of the basic compound (C) or component (F) used as needed, in a preferred content ratio. The 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) A step of applying the resist composition described above on a substrate,
(2) a step of removing the solvent from the composition after coating to form 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. Hereinafter, each of the steps shown here is referred to as “step (1)” to “step (5)”.

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

In the step (2), the solvent [solvent (E)] is removed from the resist composition coated on the substrate, that is, the coated film. Such solvent removal is performed, for example, by evaporating the solvent from the coating film by a heating means using a heating device such as a hot plate, a decompression means using a decompression device, or a combination of these means. Is called. The conditions of the heating means and the decompression means are adjusted according to the type of the solvent (E) contained in the resist composition. For example, in the heating means using a hot plate (hot plate heating), the surface of the hot plate What is necessary is just to make temperature into the range of about 50-200 degreeC. In the decompression means, after the substrate on which the coating film is formed is sealed in an appropriate decompressor, the internal pressure of the decompressor may be set to about 1 to 1.0 × 10 ⁵ Pa. Thus, the composition layer is formed on the substrate by removing the solvent from the coating film.

Step (3) is a step of exposing the composition layer, and preferably the composition layer is exposed using an exposure machine. At this time, exposure is performed through a mask corresponding to a desired pattern to be finely processed. As an exposure light source of the exposure machine, an ultraviolet light emitting device such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ laser (wavelength 157 nm), a solid-state laser light source (YAG or Various lasers such as semiconductor lasers, etc., which convert wavelength of laser light to emit harmonic laser light in the far ultraviolet region or vacuum ultraviolet region, electron beams, EUV (wavelength 13.5 nm), etc. can be used. .
As described above, by exposing through a mask, an exposed portion (exposed portion) and an unexposed portion (unexposed portion) are generated in the composition layer. In the composition layer of the exposed portion, the acid generator (B) contained in the composition layer generates an acid upon receiving exposure energy, and further, an acid labile group in the resin (A) is generated by the action with the generated acid. Causes a deprotection reaction, and as a result, the resin (A) in the composition layer of the exposed portion becomes soluble in an alkaline aqueous solution. On the other hand, since the exposure energy is not received in the unexposed area, the resin (A) remains insoluble or hardly soluble in the alkaline aqueous solution. Thus, the composition layer in the exposed portion and the composition layer in the unexposed portion are significantly different in solubility in the alkaline aqueous solution.

  In step (4), a heat treatment for further promoting the progress of the deprotecting group reaction that may occur in the exposed portion is performed. For the heat treatment, a heating means using a hot plate shown in the step (2) is employed. In the hot plate heating in step (4), the surface temperature of the hot plate is preferably about 50 to 200 ° C, more preferably about 70 to 150 ° C.

Step (5) is a step of developing the heated composition layer, and preferably the heated composition layer is developed with a developing device. The development referred to here is by bringing the composition layer after heating into contact with an alkaline aqueous solution, thereby dissolving the exposed composition layer in the alkaline aqueous solution and leaving the unexposed composition layer on the substrate. A resist pattern is manufactured on the substrate.
The alkaline aqueous solution used here is referred to as “alkaline developer”, and those used in this technical field can be used. Examples of the alkaline aqueous solution include an aqueous solution of tetramethylammonium hydroxide and an aqueous solution of (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).
The resist pattern manufactured on the substrate as described above is preferably rinsed with ultrapure water or the like to further remove moisture remaining on the substrate and the resist pattern.

<Application>
This resist composition 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 an EUV exposure machine.

Hereinafter, the present invention will be described in detail by way of examples.
In Examples and Comparative Examples, “%” and “part” representing the content and the amount used are based on mass unless otherwise specified.

The weight average molecular weight (Mw) is a value obtained by gel permeation chromatography (HLC-8120GPC, manufactured by Tosoh Corporation, three columns are “TSKgel Multipore HXL-M”, and the solvent is tetrahydrofuran) using polystyrene as a standard product. It is.
Column: TSKgel Multipore H _XL -M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

Synthesis example 1
Synthesis of compound represented by formula (1-2) (monomer (1-2))

  15.00 parts of the compound represented by the formula (1-2-a) and 100.00 parts of tetrahydrofuran were charged into a reactor and stirred at 23 ° C. for 30 minutes. After adding 20.85 parts of triethylamine to the obtained mixed liquid, 12.70 parts of the compound represented by the formula (1-2-b) was added dropwise over 30 minutes while maintaining the same temperature. did. The resulting mixture was heated to 55 ° C. and further stirred for 8 hours. The obtained reaction solution was cooled to 23 ° C., and insoluble matters were removed by filtration. The obtained filtrate was concentrated, 100 parts of ethyl acetate was added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, and then filtered again. After the collected filtrate is concentrated, the residue is subjected to column fractionation (column fractionation conditions stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., developing solvent: n-hexane / ethyl acetate = 1/1 (weight ratio)). As a result, 6.40 parts of a compound represented by the formula (1-2) was obtained as a white solid.

Mass spectrometry: 169.1 (molecular ion peak)
¹ H-NMR (CDCl ₃ , internal standard substance tetramethylsilane): δ (ppm) 1.96 (s, 3H), 2.35 (m, 1H), 2.65 (m, 1H), 4.32 (M, 1H), 4.47 (m, 1H), 4.68 (m, 1H), 5.40 (s, 1H), 5.81 (s, 1H), 7.22 (m, 1H)

式（１−８−ｂ）で表される化合物２．３１部及びＮ，Ｎ’−ジメチルホルムアミド１５．００部を、反応器に仕込み、２３℃で３０分間攪拌した。得られた混合物に、炭酸カリウム１．０７部及びヨウ化カリウム０．３４部を加え、５０℃で１時間攪拌した。得られた混合物を、４０℃まで冷却し、式（１−８−ａ）で表される化合物０．８５部をＮ，Ｎ’−ジメチルホルムアミド５．００部に溶解した溶液を１時間かけて滴下し、４０℃で５時間攪拌した。得られた混合物を、２３℃まで冷却し、クロロホルム３０．００部及び１Ｎ塩酸３０．００部を加えて攪拌・静置し、分液操作により水層と有機層とを分離した。回収された有機層に、イオン交換水３０．００部を添加し、さらに攪拌、静置及び分液するという水洗操作を、分液後の水層が中性になるまで繰り返した。回収された有機層に活性炭１．２部を加えて攪拌し、ろ過した。得られたろ液を濃縮し、濃縮物に酢酸エチル１０部を加えて攪拌し、上澄液を除去した。得られた残渣にｔｅｒｔ−ブチルメチルエーテル１０部を加えて攪拌し、上澄液を除去した。得られた残渣をクロロホルムに溶解し、濃縮した後、カラム分取（カラム分取条件 固定相：メルク社製シリカゲル６０−２００メッシュ、展開溶媒：ｎ−ヘキサン／酢酸エチル＝１／１（重量比））することにより、白色固体として、式（１−８）で表される化合物０．４５部を得た。 Synthesis example 2
Synthesis of compound represented by formula (1-8) (monomer (1-8))

2.31 parts of a compound represented by the formula (1-8-b) and 15.00 parts of N, N′-dimethylformamide were charged into a reactor and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 1.07 part of potassium carbonate and 0.34 part of potassium iodide were added and stirred at 50 ° C. for 1 hour. The obtained mixture was cooled to 40 ° C., and a solution obtained by dissolving 0.85 part of the compound represented by the formula (1-8-a) in 5.00 parts of N, N′-dimethylformamide was added over 1 hour. The solution was added dropwise and stirred at 40 ° C. for 5 hours. The obtained mixture was cooled to 23 ° C., 30.00 parts of chloroform and 30.00 parts of 1N hydrochloric acid were added, stirred and allowed to stand, and the aqueous layer and the organic layer were separated by a liquid separation operation. The water washing operation of adding 30.00 parts of ion-exchanged water to the collected organic layer and further stirring, standing and separating was repeated until the separated aqueous layer became neutral. To the recovered organic layer, 1.2 parts of activated carbon was added, stirred and filtered. The obtained filtrate was concentrated, 10 parts of ethyl acetate was added to the concentrate and stirred, and the supernatant was removed. To the obtained residue, 10 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated, followed by column fractionation (column fractionation conditions stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., developing solvent: n-hexane / ethyl acetate = 1/1 (weight ratio). )), 0.45 parts of a compound represented by the formula (1-8) was obtained as a white solid.

  Mass spectrometry: 279.1 (molecular ion peak)

式（１−Ａ−ａ）で表される化合物３３．２５部、ジシクロヘキシルカルボジイミド２３．９３部及び塩化メチレン４０．００部を、反応器に仕込み、得られた混合液に、０℃で、式（１−Ａ−ｂ）で表される化合物１８．８３部を加え、０℃で１時間攪拌した。２３℃まで昇温し、更に、３０分間攪拌した後、ろ過した。得られた濾液を濃縮して、式（１−Ａ−ｃ）で表される化合物４４．１９部を得た。

式（１−Ａ−ｃ）で表される化合物１９．３３部、式（１−Ａ−ｄ）で表される化合物１８．２０部及びアセトニトリル２００部を、反応器に仕込み、２３℃で３時間攪拌した。得られた混合物を濃縮し、クロロホルム３００部及びイオン交換水１５０部を加えた後、分液操作により、有機層を回収した。回収された有機層をイオン交換水１５０部で洗浄した後、得られた有機層を濃縮した。残渣を、カラム分取（カラム分取条件 固定相：メルク社製シリカゲル６０−２００メッシュ、展開溶媒：ｎ−ヘプタン／酢酸エチル＝２／１（重量比））することにより、式（１−Ａ）で表される化合物９．６２部を得た。 Synthesis example 3
Synthesis of monomer (1-A)

33.25 parts of a compound represented by the formula (1-Aa), 23.93 parts of dicyclohexylcarbodiimide and 40.00 parts of methylene chloride were charged into a reactor, and the resulting mixture was treated at 0 ° C. with the formula 18.83 parts of the compound represented by (1-Ab) was added, and the mixture was stirred at 0 ° C. for 1 hour. The temperature was raised to 23 ° C., and the mixture was further stirred for 30 minutes, followed by filtration. The obtained filtrate was concentrated to obtain 44.19 parts of a compound represented by the formula (1-Ac).

19.33 parts of a compound represented by the formula (1-Ac), 18.20 parts of a compound represented by the formula (1-Ad) and 200 parts of acetonitrile were charged into a reactor, and the mixture was charged with 3 at 23 ° C. Stir for hours. The obtained mixture was concentrated, 300 parts of chloroform and 150 parts of ion-exchanged water were added, and then the organic layer was recovered by a liquid separation operation. The collected organic layer was washed with 150 parts of ion-exchanged water, and then the obtained organic layer was concentrated. The residue was subjected to column fractionation (column fractionation conditions stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., developing solvent: n-heptane / ethyl acetate = 2/1 (weight ratio)) to obtain the formula (1-A ) Was obtained.

  Mass spectrometry: 226.1 (molecular ion peak)

式（１−Ａ−ｃ）で表される化合物１９．３３部、式（１−Ｂ−ａ）で表される化合物１０．２１部及びアセトニトリル２００部を、反応器に仕込み、２３℃で５時間攪拌した。得られた混合物を濃縮し、クロロホルム３００部及びイオン交換水１５０部を加えた後、分液操作により、有機層を回収した。回収された有機層をイオン交換水１５０部で洗浄した後、得られた有機層を濃縮した。残渣を、カラム分取（カラム分取条件 固定相：メルク社製シリカゲル６０−２００メッシュ、展開溶媒：ｎ−ヘプタン／酢酸エチル＝１／１（重量比））することにより、式（１−Ｂ）で表される化合物１８．７４部を得た。 Synthesis example 4
Synthesis of monomer (1-B)

19.33 parts of the compound represented by the formula (1-Ac), 10.21 parts of the compound represented by the formula (1-Ba) and 200 parts of acetonitrile were charged into a reactor, and the mixture was charged with 5 at 23 ° C. Stir for hours. The obtained mixture was concentrated, 300 parts of chloroform and 150 parts of ion-exchanged water were added, and then the organic layer was recovered by a liquid separation operation. The collected organic layer was washed with 150 parts of ion-exchanged water, and then the obtained organic layer was concentrated. The residue was subjected to column fractionation (column fractionation conditions, stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., Ltd., developing solvent: n-heptane / ethyl acetate = 1/1 (weight ratio)), and the formula (1-B ) Was obtained.

  Mass spectrometry: 227.1 (molecular ion peak)

式（１−Ａ−ｃ）で表される化合物１９．３３部、式（１−Ｃ−ａ）で表される化合物１０．２１部及びアセトニトリル２００部を、反応器に仕込み、２３℃で５時間攪拌した。得られた混合物を濃縮し、クロロホルム３００部及びイオン交換水１５０部を加えた後、分液操作により、有機層を回収した。回収された有機層をイオン交換水１５０部で洗浄した後、得られた有機層を濃縮した。残渣を、カラム分取（カラム分取条件 固定相：メルク社製シリカゲル６０−２００メッシュ、展開溶媒：ｎ−ヘプタン／酢酸エチル＝１／１（重量比））することにより、式（１−Ｃ）で表される化合物１５．１９部を得た。 Synthesis example 5
Synthesis of monomer (1-C)

19.33 parts of the compound represented by the formula (1-Ac), 10.21 parts of the compound represented by the formula (1-Ca) and 200 parts of acetonitrile were charged into a reactor, and the mixture was charged with 5 at 23 ° C. Stir for hours. The obtained mixture was concentrated, 300 parts of chloroform and 150 parts of ion-exchanged water were added, and then the organic layer was recovered by a liquid separation operation. The collected organic layer was washed with 150 parts of ion-exchanged water, and then the obtained organic layer was concentrated. The residue was subjected to column fractionation (column fractionation conditions stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., developing solvent: n-heptane / ethyl acetate = 1/1 (weight ratio)) to obtain the formula (1-C ) Was obtained.

  Mass spectrometry: 227.1 (molecular ion peak)

Resins were synthesized using the following monomers. These are referred to as “monomer (a1-1-1)” or the like according to the formula number.

Synthesis Example 6
Synthesis of Resin A1 Monomer (a1-1-1), monomer (a1-2-1), monomer (a2-1-1) and monomer (1-8) were mixed in a molar ratio [monomer (a1-1-1) : Monomer (a1-2-1): Monomer (a2-1-1): Monomer (1-8)] At 25: 10: 20: 45, charged to the reactor, 1.2 mass times the total amount of monomers Dioxane was added to make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total amount of monomers, respectively, and heated at 73 ° C. for about 5 hours. Thereafter, the reaction solution is poured into a large amount of a mixed solvent of methanol and water (methanol / water (mass ratio) = 4/1, and the same mixed solvent of methanol and water was used in the following synthesis examples) to cause precipitation. It was. The precipitate was dissolved again in dioxane and purified by pouring it in a large amount of methanol and water mixed solvent twice to obtain a resin having an Mw of 7.1 × 10 ^{3 in} a yield of 60%. It was. This resin is a copolymer having a structural unit corresponding to each monomer, and is referred to as a resin A1.

Synthesis example 7
Synthesis of Resin A2 An experiment similar to that in Synthesis Example 6 was performed except that the monomer (1-8) in the synthesis example of the resin A1 (Synthesis Example 6) was replaced with the monomer (1-2), and the Mw was about 6.9 ×. 10 ³ resins were obtained. This resin is a copolymer having a structural unit corresponding to each monomer, and is referred to as a resin A2.

Synthesis example 8
Synthesis of Resin A3 The same experiment as in Synthesis Example 6 was performed except that 10/45 of the monomer (1-8) in Synthesis Example (Synthesis Example 6) of Resin A1 was replaced with the monomer (a3-2-1). , A resin having an Mw of about 7.2 × 10 ³ was obtained. This resin is a copolymer having a structural unit corresponding to each monomer, and is referred to as a resin A3.

Synthesis Example 9
Synthesis of Resin A4 The same experiment as in Synthesis Example 7 was performed, except that 10/45 of the monomer (1-2) in Synthesis Example (Synthesis Example 7) of Resin A2 was replaced with the monomer (a3-2-1). , A resin having an Mw of about 6.8 × 10 ³ was obtained. This resin is a copolymer having a structural unit corresponding to each monomer, and is referred to as a resin A4.

Synthesis Example 10
Synthesis of Resin A5 Experiment similar to Synthesis Example 6 except that 5/20 is replaced with monomer (a2-1-2) in monomer (a2-1-1) of Synthesis Example (Synthesis Example 6) of Resin A1 And a resin having an Mw of about 7.0 × 10 ³ was obtained. This resin is a copolymer having a structural unit corresponding to each monomer, and is referred to as a resin A5.

Synthesis Example 11
Synthesis of Resin A6 The same experiment as in Synthesis Example 6 was performed except that the monomer (a1-1-1) in the synthesis example (Synthesis Example 6) of the resin A1 was replaced with the monomer (a1-1-2). A resin of 6.9 × 10 ³ was obtained. This resin is a copolymer having a structural unit corresponding to each monomer, and this is designated as resin A6.

Synthesis Example 12
Synthesis of Resin A7 An experiment similar to that in Synthesis Example 6 was performed, except that the monomer (1-8) in the synthesis example (synthesis example 6) of the resin A1 was replaced with the monomer (1-A), and the Mw was about 6.7 × 10 ³ resins were obtained. This resin is a copolymer having a structural unit corresponding to each monomer, and is referred to as a resin A7.

Synthesis Example 13
Synthesis of Resin A8 An experiment similar to that of Synthesis Example 6 was performed except that the monomer (1-8) in the synthesis example (synthesis example 6) of the resin A1 was replaced with the monomer (1-B), and the Mw was about 6.5 × 10 ³ resins were obtained. This resin is a copolymer having a structural unit corresponding to each monomer, and is referred to as a resin A8.

Synthesis Example 14
Synthesis of Resin A9 An experiment similar to that of Synthesis Example 6 was performed except that the monomer (1-8) in the synthesis example of Resin A1 (Synthesis Example 6) was replaced with the monomer (1-C), and the Mw was about 6.2 × 10 ³ resin bodies were obtained. This resin is a copolymer having a structural unit corresponding to each monomer, and is referred to as a resin A9.

Synthesis Example 15
Synthesis of Resin H1 Monomer (a1-1-2), monomer (a2-1-1) and monomer (a3-1-1) were mixed in a molar ratio [monomer (a1-1-2): monomer (a2-1-1- 1): Monomer (a3-1-1)] The reactor was charged at a ratio of 50:25:25, and then 1.5 mass times dioxane was added to the total amount of monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added at a ratio of 1 mol% and 3 mol%, respectively, with respect to all monomers, and 77 ° C. For about 5 hours. Thereafter, the reaction solution was poured into a large amount of a mixed solvent of methanol and water to cause precipitation. The precipitate is dissolved again in dioxane, poured into a large amount of methanol and water mixed solvent, and purified by performing the operation of precipitating the resin twice, and the resin having a weight average molecular weight of about 8.0 × 10 ³ Was obtained in a yield of 60%. This resin is referred to as a resin H1.

Synthesis Example 16
Synthesis of Acid Generator B1 To a mixed solution of 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 150 parts of ion exchange water, 230 parts of 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The temperature was raised (about 100 ° C.) until reflux occurred, and the mixture was refluxed for 3 hours. After cooling, the reaction mixture was neutralized by adding 88 parts of concentrated hydrochloric acid, and then concentrated to obtain 164.4 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.7%). To 1.9 parts of the obtained sodium difluorosulfoacetate (purity 62.7%) and 9.5 parts of N, N-dimethylformamide, 1.0 part of 1,1′-carbonyldiimidazole was added and stirred for 2 hours. Solution I was obtained. In a separate vessel, charge 1.1 parts of 3-hydroxy-1-adamantylmethanol and 5.5 parts of N, N-dimethylformamide, add 0.2 parts of sodium hydride, and stir for 2 hours. Solution II was obtained. Solution I was added to Solution II and stirred for 15 hours. Thus, a solution containing the product difluorosulfoacetate 3-hydroxy-1-adamantyl methyl ester sodium salt was obtained.

  To the resulting solution containing 3-hydroxy-1-adamantyl methyl ester sodium salt of difluorosulfoacetic acid, 17.2 parts of chloroform and 2.9 parts of a 14.8% aqueous triphenylsulfonium chloride solution were added. After stirring for 15 hours, the organic layer and the aqueous layer which were allowed to stand and separated into two layers were separated by a liquid separation operation. The aqueous layer was further extracted with 6.5 parts of chloroform, and this chloroform extract was combined with the organic layer and further washed with ion-exchanged water. The organic layer after washing with water is concentrated, 5.0 parts of tert-butyl methyl ether is added to the residue, and the mixture is stirred and filtered to give triphenylsulfonium 1-((3-hydroxy-1-adamantyl) methoxycarbonyl as a white solid. ) 0.2 part of difluoromethanesulfonate (B1-2) was obtained.

Examples 1-9 and Comparative Examples 1-2
Each component shown in Table 1 was mixed and dissolved, and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a liquid resist composition.

Quencher (Q1): 2,6-diisopropylaniline Solvent:
Propylene glycol monomethyl ether acetate 265 parts 2-heptanone 20 parts Propylene glycol monomethyl ether 20 parts γ-butyrolactone 3.5 parts

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

  In each composition layer, an exposure amount at which the 50 nm line and space pattern becomes an exposure amount of 1: 1 was defined as an effective sensitivity.

Resolution evaluation In effective sensitivity, a resist pattern is observed with a scanning electron microscope, and “g” (good) indicates that 45 nm is resolved, “b” indicates that resolution is not resolved or pattern collapse is observed. (Bad).

Shape Evaluation A 50 nm line and space pattern was observed with a scanning electron microscope. A top shape and a skirt shape that are close to a rectangle and good are indicated as “g” (good), and a top shape that is round or close to a T-shape, or a skirt that is skirted is indicated as “b” (bad).

  The resist composition of the present invention is useful for fine processing of semiconductors.

Claims (9)

A resist composition comprising a resin having a structural unit derived from the monomer represented by formula (1), an acid generator, and a solvent.

[In Formula (1),
R ¹ and R ² each independently represents a hydrogen atom or a C _1-4 alkyl group.
A ¹ represents a single bond, a group represented by * 1- (CH ₂ ) _m —CO—O— * 2, or a group represented by * 1- (CH ₂ ) _n —CO—NR ³ * 2. R ³ represents a hydrogen atom or a C _1-4 alkyl group. m and n each independently represent an integer of 1 to 6, * 1 is of the nitrogen atom, * 2 represents a bond to ^{B 1.}
B ¹ represents a C _4-20 lactone ring group which may have a substituent. ] The resist composition according to claim 1, wherein B ^{1 in the} formula (1) is a group represented by the formula (2) or the formula (3).

[In Formula (2),
p represents an integer of 0 to 3, and R ⁴ represents a C _1-4 alkyl group. When p is 2 or more, the plurality of R ⁴ are each independent.
q represents an integer of 0 to 3, and R ⁵ represents a carboxy group, a cyano group, or a C _1-4 alkyl group. When q is 2 or more, the plurality of R ⁵ are each independent. ]   The resist composition according to claim 1, wherein the resin is a resin that is insoluble or hardly soluble in an alkaline aqueous solution and becomes soluble in an alkaline aqueous solution by the action of an acid. The resist composition according to claim 1, wherein the acid generator is an acid generator represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C _1-6 perfluoroalkyl group.
L ^b1 represents a C _1-17 aliphatic hydrocarbon group or a single bond which may have a substituent, and —CH ₂ — contained in the aliphatic hydrocarbon group is —O— or —CO—. May be replaced.
Y represents an _optionally substituted C _1-36 aliphatic hydrocarbon group, and —CH ₂ — contained in the aliphatic hydrocarbon group is —O—, —SO ₂ — or —CO. -May be substituted.
Z ⁺ represents an organic cation. ] The resist composition according to claim 4, wherein L ^{b1 in the} formula (B1) is * —CO—O— (* represents a bond with —C (Q ¹ ) (Q ² ) —). The resist composition according to claim 4 or 5, wherein Z ^{+ in the} formula (B1) is an arylsulfonium cation.   Furthermore, the resist composition in any one of Claims 1-6 containing a basic compound.   The resist composition according to claim 7, wherein the basic compound is a nitrogen-containing basic compound. (1) The process of apply | coating the resist composition in any one of Claims 1-8 on a board | substrate,
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure,
(5) a step of developing the composition layer after heating;
A method for producing a resist pattern including: