WO2015045739A1

WO2015045739A1 - Radiation-sensitive resin composition, method for forming resist pattern, polymer, and compound

Info

Publication number: WO2015045739A1
Application number: PCT/JP2014/072838
Authority: WO
Inventors: 仁視大▲崎▼; 準人生井
Original assignee: Jsr株式会社
Priority date: 2013-09-25
Filing date: 2014-08-29
Publication date: 2015-04-02
Also published as: JP6421757B2; JPWO2015045739A1

Abstract

　The present invention is a radiation-sensitive resin composition containing a polymer having a structure unit that includes a group represented by formula (1), and a radiation-sensitive acid generator. In formula (1), R¹ is a monovalent C2-30 organic group, which includes at least one element selected from the group comprising O and N. R² is a C5-20 alicyclic hydrocarbon group which includes a double bond. R^a and R^b are independently a hydrogen or a C1-10 monovalent hydrocarbon group. The asterisk indicates the site of the abovementioned structure unit that is bonded to another portion. The groups represented in formula (1) are preferably acid-dissociable.

Description

Radiation sensitive resin composition, resist pattern forming method, polymer and compound

The present invention relates to a radiation sensitive resin composition, a resist pattern forming method, a polymer and a compound.

Chemically amplified radiation-sensitive resin compositions used for microfabrication by lithography are irradiated with far ultraviolet rays such as ArF excimer laser light, electromagnetic waves such as extreme ultraviolet rays (EUV) and X-rays, and charged particle beams such as electron beams. Thus, an acid is generated in the exposed portion, and a resist pattern is formed by causing a difference in dissolution rate in the developing solution between the exposed portion and the unexposed portion by a chemical reaction using this acid as a catalyst.

Such a radiation-sensitive resin composition is required to improve lithography performance such as sensitivity and resolution as processing technology becomes finer. In response to this demand, various structures of acid-dissociable groups possessed by the polymer contained in the radiation-sensitive resin composition have been studied. The acid-dissociable group is a hydrocarbon group containing a carbon-carbon double bond. Some are also known (see JP 2000-128930 A, JP 10-140018 A, and JP 6-289615 A).

However, at present, when the miniaturization of resist patterns has progressed to a level of 40 nm or less, the required level of resolution of the radiation-sensitive resin composition has further increased, and in addition, LWR (Line Width Roughness). ) It is required to have excellent performance and defect suppression. However, the conventional radiation-sensitive resin composition cannot satisfy these performances.

JP 2000-128930 A Japanese Patent Laid-Open No. 10-140018 JP-A-6-289615

The present invention has been made on the basis of the above circumstances, and an object thereof is to provide a radiation-sensitive resin composition excellent in resolution, LWR performance and defect suppression.

The invention made to solve the above problems is
A polymer having a structural unit (hereinafter also referred to as “structural unit (I)”) containing a group represented by the following formula (1) (hereinafter also referred to as “group (I)”) (hereinafter referred to as “[A]”). Polymer ”), and radiation-sensitive acid generator (hereinafter also referred to as“ [B] acid generator ”).
Is a radiation-sensitive resin composition.

(In Formula (1), R ¹ is a monovalent organic group having 2 to 30 carbon atoms including at least one selected from the group consisting of O, N and S. R ² includes a double bond. An alicyclic hydrocarbon group having 5 to 20 carbon atoms, wherein R ^a and R ^b are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, * represents the above structure Indicates the site that binds to the other part of the unit.)

Another invention made to solve the above problems is as follows:
Forming a resist film;
A step of exposing the resist film, and a step of developing the exposed resist film,
It is a resist pattern formation method which forms the said resist film with the said radiation sensitive resin composition.

Yet another invention made to solve the above problems is as follows:
It is a polymer which has a structural unit containing group represented by the said Formula (1).

Yet another invention made to solve the above problems is as follows:
It is a compound represented by the following formula (i).

(In Formula (i), R ¹ is a monovalent organic group having 2 to 30 carbon atoms including at least one selected from the group consisting of O, N and S. R ² includes a double bond. An alicyclic hydrocarbon group having 5 to 20 carbon atoms, R ^a and R ^b are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and Y is polymerizable. (It is a monovalent group containing a carbon-carbon double bond.)

Here, the “hydrocarbon group” includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The “hydrocarbon group” may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The “chain hydrocarbon group” refers to a hydrocarbon group that does not include a cyclic structure but includes only a chain structure, and includes both a linear hydrocarbon group and a branched hydrocarbon group. The term “alicyclic hydrocarbon group” refers to a hydrocarbon group that includes only an alicyclic structure as a ring structure and does not include an aromatic ring structure, and includes a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic group. Includes both hydrocarbon groups. However, it is not necessary to be composed only of the alicyclic structure, and a part thereof may include a chain structure. “Aromatic hydrocarbon group” refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic structure.
“Organic group” refers to a group containing at least one carbon atom.

According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, a resist pattern with high resolution, low LWR, and few defects can be formed. The polymer of this invention can be used suitably as a polymer component of the said radiation sensitive resin composition. The compound of the present invention can be suitably used as a raw material monomer for the polymer. Therefore, these can be suitably used in a semiconductor manufacturing process that is expected to be further miniaturized in the future.

<Radiation sensitive resin composition>
The radiation-sensitive resin composition contains a [A] polymer and a [B] acid generator. The radiation-sensitive resin composition may contain a [C] acid diffusion controller, a [D] fluorine atom-containing polymer, and a [E] solvent as suitable components, as long as the effects of the present invention are not impaired. In addition, other optional components may be contained. Hereinafter, each component will be described.
Hereinafter, each component will be described.

<[A] polymer>
[A] The polymer is a polymer having the structural unit (I). The said radiation sensitive resin composition is excellent in resolution, LWR performance, and defect inhibitory property because a [A] polymer has structural unit (I). The reason why the radiation-sensitive resin composition exhibits the above-described effect by having the above-described configuration is not necessarily clear, but can be inferred as follows, for example. That is, the group (I) in the structural unit (I) of the polymer [A] has at least one atom selected from the group consisting of O, N and S (hereinafter also referred to as “atom such as O”). R ¹ group and R ² group containing a carbon-carbon double bond. [B] The acid generator usually has high polarity. Therefore, it is considered that there is a high affinity between the group (I) and the [B] acid generator, and the degree that the [B] acid generator exists in the vicinity of the [A] polymer increases. Therefore, the dissociability of the acid-dissociable group of the [A] polymer is increased, and as a result, the resolution, LWR performance and defect suppression of the radiation-sensitive resin composition are improved.

[A] The polymer is a structural unit (II) containing at least one structure selected from the group consisting of a lactone structure, a cyclic carbonate structure and a sultone structure in addition to the structural unit (I), It may have a structural unit (III) represented, a structural unit (IV) containing a polar group, and the like. [A] The polymer may have one or more of these structural units. Hereinafter, each structural unit will be described.

[Structural unit (I)]
The structural unit (I) is a structural unit containing a group represented by the following formula (1).

In the above formula (1), R ¹ is a monovalent organic group having 2 to 30 carbon atoms and containing at least one selected from the group consisting of O, N and S. R ² is an alicyclic hydrocarbon group having 5 to 20 carbon atoms containing a double bond. R ³ and R ⁴ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. * Indicates a site that binds to another part in the structural unit.

Examples of the monovalent organic group having 2 to 30 carbon atoms including at least one selected from the group consisting of O, N and S represented by R ¹ include, for example, carbon of a hydrocarbon group having 2 to 20 carbon atoms. A group (A) containing a divalent group having at least one selected from the group consisting of O, N and S between carbons, a part or all of the hydrogen atoms of the hydrocarbon group and the group (A) And a group (B) substituted with a monovalent group having at least one selected from the group consisting of O, N and S.

Examples of the monovalent hydrocarbon group having 2 to 20 carbon atoms include:
A chain hydrocarbon group having 2 to 20 carbon atoms such as an alkyl group such as an ethyl group, a propyl group and a butyl group, an alkenyl group such as an ethenyl group and a propenyl group, and an alkynyl group such as an ethynyl group and a propynyl group;
An alicyclic hydrocarbon group having 3 to 20 carbon atoms such as a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group, and a cycloalkenyl group such as a cyclopentenyl group and a norbornenyl group;
Examples thereof include aryl groups such as phenyl group, tolyl group and naphthyl group, and aromatic hydrocarbon groups having 6 to 20 carbon atoms such as aralkyl groups such as benzyl group and phenethyl group.
Of these, a chain hydrocarbon group and an alicyclic hydrocarbon group are preferable, an alkyl group and a cycloalkyl group are more preferable, and an ethyl group, a 2-propyl group, and a cyclopropyl group are more preferable.

Examples of the divalent group having at least one selected from the group consisting of O, N and S include, for example, —COO—, —CONR′—, —SO—, —O—, —S—, —CO—. , —NR′—, —CS—, —SO ₂ —, —SO ₃ — and the like. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.
Of these, —COO—, —CONR′— and —SO— are preferable, and —COO— is more preferable.

Examples of the monovalent group having at least one selected from the group consisting of O, N and S include cyano group, hydroxy group, sulfanyl group (—SH), —NR ″ _{2 and the} like. Is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.
Of these, a cyano group and a hydroxy group are preferred.

R ¹ is preferably the above group (A) or the above group (B), and is —COO— or —CONR between the carbon and carbon of the alkyl group having 2 to 20 carbon atoms or the cycloalkyl group having 3 to 20 carbon atoms. A group (a) containing at least one selected from the group consisting of '-and -SO-, and at least one selected from the group consisting of a cyano group and a hydroxy group in which part or all of the hydrogen atoms of the group (a) are present More preferably, the group (b) (R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms) substituted with a seed, an alkyl group having 2 to 20 carbon atoms or a group having 3 to 20 carbon atoms. A group (a) containing at least one selected from the group consisting of —COO—, —CONR′— and —SO— between the carbons of the cycloalkyl group is more preferred, and an ethyl group, a 2-propyl group or a cyclopropyl group is more preferable. Group carbon A group containing one or two —COO— between the carbon atoms is particularly preferable, and a methoxycarbonylmethyl group, a butyrolactone-yl group, and a di (methoxycarbonyl) methyl group are more particularly preferable.

In addition, R ¹ is preferably a group (1-a) represented by the following formula (a). When R ¹ is the group (1-a), atoms such as O in the group (I) can be arranged at more appropriate positions. As a result, the resolution of the radiation-sensitive resin composition can be improved. , LWR performance and defect suppression can be further improved.

In the above formula (a), R ³ and R ⁴ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. n is 1 or 2. When n is 2, the plurality of R ³ and R ⁴ may be the same or different. R ⁴ and R ⁵ may be combined with each other to represent a ring structure having 3 to 20 ring members that is composed of L and the carbon atom to which R ⁴ is bonded. L is —COO—, —CONR′— or —SO—. R ⁵ is a monovalent hydrocarbon group having 1 to 20 carbon atoms.

Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ³ and R ⁴ include, for example,
A chain hydrocarbon group such as an alkyl group such as a methyl group, an ethyl group or a propyl group, an alkenyl group such as an ethenyl group or a propenyl group, an alkynyl group such as an ethynyl group or a propynyl group;
An alicyclic hydrocarbon group such as a cycloalkyl group such as a cyclopropyl group and a norbornyl group, a cycloalkenyl group such as a cyclopropenyl group and norbornenyl;
Examples thereof include aryl groups such as phenyl group, tolyl group and naphthyl group, and aromatic hydrocarbon groups such as aralkyl groups such as benzyl group and phenethyl group.
Among these, a chain hydrocarbon group is preferable, an alkyl group is more preferable, a methyl group and an ethyl group are further preferable, and a methyl group is particularly preferable.

R ³ and R ⁴ are preferably a hydrogen atom.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ⁵ include the groups exemplified as the monovalent hydrocarbon group having 2 to 20 carbon atoms of R ¹ and a methyl group. .
Among these, a chain hydrocarbon group is preferable, an alkyl group is more preferable, a methyl group and an ethyl group are further preferable, and a methyl group is particularly preferable.

Examples of the ring structure having 3 to 20 ring members constituted by R ⁴ and R ⁵ combined with each other and the carbon atom to which R ⁴ is bonded and L include, for example,
Lactone structures such as butyrolactone structure, valerolactone structure, caprolactone structure;
Lactam structures such as butyrolactam structure, valerolactam structure, caprolactam structure;
Examples thereof include cyclic sulfoxide structures such as an oxothiacyclobutane structure and an oxothiacyclopentane structure.
Among these, a lactone structure is preferable and a butyrolactone structure is more preferable.

L is preferably —COO—.

N is preferably 1 from the viewpoint of improving the LWR performance and the like of the radiation-sensitive resin composition, and from the viewpoint of the ease of synthesis of the monomer that gives the structural unit (I).

Examples of the alicyclic hydrocarbon group having 5 to 20 carbon atoms containing a double bond represented by R ² include a cyclopentenetetrayl group, a cyclohexenetetrayl group, a cycloheptenetetrayl group, and a cyclooctenetetrayl group. A group containing a monocyclic cycloalkene skeleton such as a cyclodecenetetrayl group;
And a group containing a polycyclic cycloalkene skeleton such as a bicyclo [4.4.0] decenetetrayl group, a bicyclo [3.1.1] heptenetetrayl group, and a tricyclodecenetetrayl group.

The number of ring members of the alicyclic hydrocarbon group of R ² is preferably 5 to 15, more preferably 5 to 10, and still more preferably 5 to 8.

Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ^a and R ^b include those having 1 to 10 carbon atoms among the monovalent hydrocarbon groups represented by R ⁵ above. Is mentioned.
Among these, a chain hydrocarbon group is preferable, an alkyl group is more preferable, and a methyl group is more preferable.

As said R ^<a> and R ^<b> , a hydrogen atom is preferable.

Examples of the group (I) include groups represented by the following formulas (1-1) to (1-16) (hereinafter also referred to as “groups (I-1) to (I-16)”). Can be mentioned.

In the above formulas (1-1) to (1-16), * has the same meaning as the above formula (1).

Among these, the groups (I-1) to (I-5) are preferable as the group (I).

The group (I) preferably has acid dissociation properties. When the group (I) is an acid-dissociable group, the resolution, LWR performance, and defect suppression of the radiation-sensitive resin composition are improved. The “acid-dissociable group” refers to a group that replaces a hydrogen atom such as a carboxy group, a phenolic hydroxyl group, or a sulfo group, and that dissociates by the action of an acid. When the group (I) is bonded to —COO—, phenolic —O—, —SO ₂ —O— or the like, R ¹ of the group (I) has an atom such as O and has an electron withdrawing property. However, since the dissociation property is enhanced by the presence of a carbon-carbon double bond adjacent to the carbon atom that becomes the bonding site of the group (I), the group (I) usually has acid dissociation properties. It becomes. In addition, as described above, the acid dissociable group is considered to have the [B] acid generator closer to each other, so that the dissociability is further enhanced. As a result, the resolution, LWR performance, and defect suppression of the radiation sensitive resin composition are further improved.

The structural unit (I) is composed of structural units represented by the following formulas (2-1) to (2-3) (hereinafter also referred to as “structural units (I-1) to (I-3)”). At least one selected from the group is preferred.

In the above formulas (2-1) to (2-3), Z is a group represented by the above formula (1).
In the above formula (2-1), R ⁶ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
In the above formula (2-2), R ⁷ is a hydrogen atom or a methyl group. E is a single bond or a divalent linking group. Ar ¹ is a substituted or unsubstituted arenediyl group having 6 to 30 carbon atoms.
In the above formula (2-3), R ⁸ is a hydrogen atom or a methyl group. R ⁹ and R ¹⁰ are each independently a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms. Two or more of one or more of R ⁹ and R ¹⁰ may be combined with each other to form a ring structure having 3 to 20 ring members that is configured together with the carbon atom to which they are bonded. m is an integer of 1 to 4. When m is 2 or more, the plurality of R ⁹ and R ¹⁰ may be the same or different. R ¹¹ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. G is a single bond or a divalent linking group. R ¹¹ and G may be combined with each other to form a ring structure with 3 to 20 ring members that is composed of carbon atoms to which they are bonded.

R ⁶ is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoint of copolymerization of the monomer that gives the structural unit (I).
R ⁷ and R ⁸ are preferably a hydrogen atom from the viewpoint of the copolymerizability of the monomer that gives the structural unit (I).

Examples of the divalent linking group represented by E and G include —O—, —COO—, —CONR′—, a divalent organic group, and the like. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.
E is preferably a single bond, —COO— or —CONR′—, and more preferably a single bond.
G is preferably a single bond or an alkanediyl group, and more preferably a single bond or a methanediyl group.

Examples of the arenediyl group having 6 to 30 carbon atoms represented by Ar ¹ include a benzenediyl group, a naphthalenediyl group, and an anthracenediyl group.
Of these, a benzenediyl group is preferred.
Examples of the substituent for the arenediyl group include a monovalent hydrocarbon group having 1 to 10 carbon atoms, a cyano group, a hydroxy group, and a halogen atom.

Examples of the halogen atom represented by R ⁹ and R ¹⁰ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ⁹ and R ¹⁰ include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms and a monovalent oxycarbonated carbon having 1 to 20 carbon atoms. Examples thereof include a hydrogen group, a carbonyloxy hydrocarbon group having 2 to 20 carbon atoms, an acyl group having 2 to 20 carbon atoms, a cyano group, and a carboxy group. Among these, a monovalent hydrocarbon group having 1 to 20 carbon atoms is preferable, a monovalent chain hydrocarbon group having 1 to 10 carbon atoms is more preferable, and an alkyl group having 1 to 10 carbon atoms is more preferable. A methyl group is particularly preferred.
Examples of the ring structure having 3 to 20 ring members constituted by combining two or more of these groups together include, for example, a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a norbornane structure, an adamantane structure, and the like. Examples include alicyclic structures.
As the ^{R 9} and ^{R 10,} a hydrogen atom, preferably a methyl group, and more preferably a hydrogen atom.

M is preferably 1 or 2, and more preferably 1.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹¹ include the same groups as the monovalent organic groups exemplified as R ⁹ and R ¹⁰ above.
Among these, a monovalent hydrocarbon group having 1 to 20 carbon atoms is preferable, a monovalent chain hydrocarbon group having 1 to 10 carbon atoms is more preferable, and an alkyl group having 1 to 10 carbon atoms is more preferable. A methyl group and an ethyl group are particularly preferable.
R ¹¹ is preferably a hydrogen atom, a methyl group, or an ethyl group, and more preferably a methyl group or an ethyl group.

Examples of the ring structure having 3 to 20 ring members composed of the carbon atoms to which R ¹¹ and G are combined and bonded to each other include alicyclic rings such as a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, and a cyclohexane structure. Structure: Aliphatic heterocyclic structures such as an oxacyclopentane structure, an azacyclopentane structure, and a thiacyclopentane structure are exemplified.
Among these, an alicyclic structure is preferable, and a cyclopentane structure and a cyclohexane structure are more preferable.

Examples of the structural unit (I-1) include a structural unit represented by the following formula (2-1-1) or (2-1-2), and the structural unit (I-2) The structural units represented by (2-2-1) to (2-2-3) are represented by the following formulas (2-3-1) to (2-3-3) as the structural unit (I-3). ) And the like.

In the above formulas (2-1-1) to (2-3-3), Z has the same meaning as the above formulas (2-1) to (2-3).

Among these, the structural unit (I) is preferably the structural unit (I-1), more preferably the structural unit represented by the above formula (2-1-1).

As an upper limit of the content rate of structural unit (I), 5 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 30 mol% is more preferable, 50 mol% is further more preferable, 75 mol % Is particularly preferred. As a minimum of the content rate of structural unit (I), 100 mol% is preferable, 95 mol% is more preferable, 90 mol% is further more preferable, 85 mol% is especially preferable. By making the content rate of structural unit (I) into the said range, the resolution, LWR performance, and defect inhibitory property of the said radiation sensitive resin composition can be improved. When the content rate of structural unit (I) is less than the said minimum, the pattern formation property of the said radiation sensitive resin composition may fall.

The content ratio of the structural unit (I) is 100 mol%, and the [A] polymer is a homopolymer having the structural unit (I), so that the polymer has physical properties resulting from having a plurality of types of structural units. The deterioration of the performance of the radiation sensitive resin composition due to variation can be eliminated, and the resolution, LWR performance, and defect suppression can be further improved.

Examples of the monomer that gives the structural unit (I) include a compound represented by the following formula (i) (hereinafter also referred to as “compound (i)”).

In the above formula (i), R ¹ is a C 2-30 monovalent organic group containing at least one selected from the group consisting of O, N and S. R ² is an alicyclic hydrocarbon group having 5 to 20 carbon atoms containing a double bond. R ^a and R ^b are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Y is a monovalent group containing a polymerizable carbon-carbon double bond.

Examples of Y in the compound (i) include groups represented by the following formulas (y-1) to (y-3).

In the above formulas (y-1) to (y-3), * represents a bonding site to the carbon atom to which R ¹ in the above formula (i) is bonded.
In the above formula (y-1), R ⁶ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
In the above formula (y-2), R ⁷ is a hydrogen atom or a methyl group. E is a single bond or a divalent linking group. Ar ¹ is a substituted or unsubstituted arenediyl group having 6 to 30 carbon atoms.
In the above formula (y-3), R ⁸ is a hydrogen atom or a methyl group. R ⁹ and R ¹⁰ are each independently a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms. Two or more of one or more of R ⁹ and R ¹⁰ may be combined with each other to form a ring structure having 3 to 20 ring members that is configured together with the carbon atom to which they are bonded. m is an integer of 1 to 4. When m is 2 or more, the plurality of R ⁹ and R ¹⁰ may be the same or different. R ¹¹ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. G is a single bond or a divalent linking group. R ¹¹ and G may be combined with each other to form a ring structure with 3 to 20 ring members that is composed of carbon atoms to which they are bonded.

Y is preferably a group represented by the above formula (y-1).

Examples of the compound (i) include compounds represented by the following formulas (i1) to (i16).

In the above formulas (i1) to (i16), each R ⁶ is independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ⁷ is each independently a hydrogen atom or a methyl group. R ⁸ is each independently a hydrogen atom or a methyl group.

As the compound (i), compounds represented by the above formulas (i1) to (i5) are preferable.

The compound (i) is, for example, a compound (i ′) in which Y in the above formula (i) is Y′COO (Y ′ is a monovalent group containing a polymerizable carbon-carbon double bond). In this case, it is as follows, and can be synthesized simply and with high yield according to the following scheme.

In the above scheme, R ¹ is a monovalent organic group having 2 to 30 carbon atoms and containing at least one selected from the group consisting of O, N and S. R ² is an alicyclic hydrocarbon group having 5 to 20 carbon atoms containing a double bond. R ^a and R ^b are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. X is a halogen atom. G is a halogen atom, a hydroxy group or —OCOR ″. R ″ is a monovalent hydrocarbon group. Y ′ is a monovalent group containing a polymerizable carbon-carbon double bond.

An α, β-unsaturated cyclic ketone compound represented by the above formula (ia) and an organic halide represented by R ¹ X in the presence of zinc and trimethylsilyl chloride as an activator and the like A hydroxy compound represented by the above formula (ib) is obtained by reacting in a solvent such as This hydroxy compound and a compound represented by Y′COG (G is a halogen atom, a hydroxy group or —OCOR ″) are mixed with a base such as triethylamine or 1,4-diazabicyclo [2.2.2] octane. In the presence, the compound (i ′) is produced by reacting in a solvent such as acetonitrile, etc. The compound (i ′) obtained is purified by a method such as column chromatography, recrystallization, distillation, etc. Can be separated.

The halogen atom represented by X is preferably a chlorine atom or a bromine atom.
The halogen atom represented by G is preferably a chlorine atom or a bromine atom, and more preferably a chlorine atom.

Compound (i) other than the above compound (i ′) can also be synthesized by the same method as described above.

[Structural unit (II)]
The structural unit (II) is a structural unit including at least one structure selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure. [A] It is thought that the solubility of the polymer can be appropriately adjusted by having the structural unit (II). Moreover, the adhesiveness to the board | substrate etc. of the resist pattern formed from the said radiation sensitive resin composition can be improved. As a result, the LWR performance and EL performance of the radiation sensitive resin composition can be improved. Here, the lactone structure refers to a structure having one ring (lactone ring) including a group represented by —O—C (O) —. The cyclic carbonate structure refers to a structure having one ring (cyclic carbonate ring) containing a group represented by —O—C (O) —O—. The sultone structure refers to a structure having one ring (sultone ring) including a group represented by —O—S (O) ₂ —.

Examples of the structural unit (II) include a structural unit represented by the following formula (3).

In said formula (3), R < ¹² > is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ¹³ is a single bond or a divalent linking group. R ¹⁴ is a monovalent group containing a lactone structure, a monovalent group containing a cyclic carbonate structure, or a monovalent group containing a sultone structure.

R ¹² is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoint of copolymerization of the monomer that gives the structural unit (II).

Examples of the divalent linking group represented by R ¹³ include, for example, a divalent linear or branched hydrocarbon group having 1 to 20 carbon atoms, one or more of these hydrocarbon groups, and —CO—, And groups composed of at least one group selected from the group consisting of —O—, —NH—, and —S—.

Examples of the monovalent group containing a lactone structure represented by R ¹⁴ , the monovalent group containing a cyclic carbonate structure, and the monovalent group containing a sultone structure include the following formulas (g-1) to (g- 11) etc. are mentioned.

In the above formulas (g-1) to (g-4), R ^L1 is an oxygen atom or a methylene group. R ^L2 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n _L1 is 0 or 1. n _L2 is an integer of 0 to 3.
In the above formulas (g-7) and (g-8), n _C1 is an integer of 0-2. n _C2 to n _C5 are each independently an integer of 0 to 2.
In the above formulas (g-8) to (g-11), R ^S1 is an oxygen atom or a methylene group. R ^S2 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n _S1 is 0 or 1. n _S2 is an integer of 0 to 3.
In the above formulas (g-1) to (g-11), * represents a site that binds to R ⁴ in the above formula (3).
Some or all of the hydrogen atoms contained in the groups represented by the above formulas (g-1) to (g-11) may be substituted.

Among these, R ¹⁴ is (g-1), (g-3), (g-7) from the viewpoint of improving the resolution, LWR performance and defect suppression of the radiation-sensitive resin composition. ) And (g-9) are preferred, groups represented by (g-1) and (g-7) are more preferred, and groups represented by (g-1) are more preferred.
As said R ^<L1> and R ^<S1> , a methylene group is preferable. As R ^L2 and R ^S2 , a hydrogen atom is preferable. As said _nL1 and _nS1 , 0 is preferable. As said _nL2 and _nS2 , 1 or 2 is preferable and 1 is more preferable.
The group that replaces the hydrogen atom of the norbornane ring of the groups represented by (g-1) and (g-7) is preferably a cyano group, a trifluoromethyl group, or a methoxycarbonyl group, and more preferably a cyano group. .

Examples of the structural unit (II) include a structural unit represented by the following formula.

In the above formula, R ¹² is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

The content ratio of the structural unit (II) is preferably 0 to 95 mol%, more preferably 0 to 50 mol%, further preferably 0 to 25 mol%, and particularly preferably 0 mol%. By making the content rate of structural unit (II) into the said range, the resolution of the said radiation sensitive resin composition, LWR performance, and defect inhibitory property can be combined at a higher level. In addition, the adhesion of the formed resist pattern to the substrate or the like can be improved. When the content rate of structural unit (II) exceeds the said upper limit, the pattern formation property of the said radiation sensitive resin composition may fall.

[Structural unit (III)]
The structural unit (III) is a structural unit represented by the following formula (4). [A] In addition to the structural unit (I), the polymer [A] can further have a structural unit (III) having an acid-dissociable group, thereby adjusting the solubility in the developer to an appropriate level. As a result, the dissolution contrast by the radiation sensitive resin composition can be improved, and the resolution, LWR performance, and defect suppression can be combined at a higher level.

In the formula (4), R ¹⁵ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ¹⁶ is a monovalent chain hydrocarbon group having 1 to 10 carbon atoms. R ¹⁷ and R ¹⁸ are each independently a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or these groups are It represents an alicyclic structure having 3 to 20 ring members that is formed together with the carbon atoms to which they are bonded together.

R ¹⁵ is preferably a hydrogen atom or a methyl group, more preferably a methyl group, from the viewpoint of copolymerization of the monomer that gives the structural unit (III).

Examples of the monovalent chain hydrocarbon group having 1 to 10 carbon atoms represented by R ¹⁶ , R ¹⁷ and R ¹⁸ include, for example,
Saturated hydrocarbon groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, and t-butyl;
Examples thereof include unsaturated hydrocarbon groups such as ethenyl group, propenyl group, butenyl group, ethynyl group and propynyl group.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by the above R ¹⁷ and R ¹⁸ include:
Saturated monocyclic hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclopentyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group;
Unsaturated monocyclic hydrocarbon groups such as cyclopropenyl group, cyclobutenyl group, cyclopentenyl group, cyclohexenyl group, cyclooctenyl group, cyclodecenyl group;
Saturated polycyclic hydrocarbon groups such as bicyclo [2.2.1] heptanyl group, bicyclo [2.2.2] octanyl group, tricyclo [3.3.1.1 ^3,7 ] decanyl group;
And unsaturated polycyclic hydrocarbon groups such as a bicyclo [2.2.1] heptenyl group and a bicyclo [2.2.2] octenyl group.

Examples of the alicyclic structure having 3 to 20 ring members constituted by the carbon atoms to which these groups are combined and bonded to each other include monocyclic rings such as a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, and a cyclohexane structure. A cycloalkane structure; a polycyclic cycloalkane structure such as a norbornane structure and an adamantane structure.

Examples of the structural unit (III) include structural units represented by the following formulas (4-1) to (4-4) (hereinafter also referred to as “structural units (III-1) to (III-4)”). Etc.

In the above formulas (4-1) to (4-4), R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are as defined in the above formula (4). n _p is an integer of 1 to 4.

As _np , 1, 2 or 4 is preferable and 1 is more preferable.

Examples of the structural units (III-1) to (III-4) include structural units represented by the following formulas.

In the above formula, R ¹⁵ has the same meaning as the above formula (4).

As the structural unit (III), the structural unit (III-1) and the structural unit (III-2) are preferable from the viewpoint of further improving the resolution, LWR performance, and defect suppression of the radiation-sensitive resin composition. The structural unit (III-2) is more preferable, and the structural unit derived from 1-methyl-1-cyclopentyl (meth) acrylate is more preferable.

The content ratio of the structural unit (III) is preferably 0 mol% to 80 mol%, more preferably 0 mol% to 60 mol%, still more preferably 0 mol% to 30 mol%, and particularly preferably 0 mol%. By making the content rate of structural unit (III) into the said range, the resolution, LWR performance, and defect inhibitory property of the said radiation sensitive resin composition can be combined at a still higher level. When the content ratio of the structural unit (II) exceeds the above upper limit, the adhesion of the formed resist pattern to the substrate may be lowered.

[Structural unit (IV)]
The structural unit (IV) is a structural unit containing a polar group (except for those corresponding to the structural unit (I)). [A] Since the polymer further has the structural unit (IV), the solubility of the [A] polymer can be adjusted appropriately, so that the dissolution contrast can be improved. As a result, the radiation-sensitive resin composition The resolution of the object, the LWR performance, and the defect suppression can be combined at a higher level.

Examples of the polar group include a hydroxy group, a carboxy group, a cyano group, a carbonyl group, a nitro group, and a sulfonamide group. Among these, a hydroxy group, a carboxy group, and a carbonyl group are preferable, and a hydroxy group is more preferable.

Examples of the structural unit (IV) include a structural unit represented by the following formula.

In the above formula, R ¹⁹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

Among these, a structural unit containing a hydroxy group is preferred, a structural unit having a hydroxy group and an adamantane skeleton is more preferred, and a structural unit derived from 3-hydroxy-1-adamantyl (meth) acrylate is more preferred.

The content of the structural unit (IV) is preferably 0 mol% to 30 mol%, more preferably 0 mol% to 20 mol%, still more preferably 0 mol% to 15 mol%. By making the content rate of structural unit (IV) into the said range, the resolution of the said radiation sensitive resin composition, LWR performance, and defect inhibitory property can be combined at a higher level.

[Other structural units]
[A] The polymer may have other structural units other than the structural units (I) to (IV). Examples of the other structural unit include a structural unit containing a non-acid dissociable alicyclic hydrocarbon group. As a content rate of the said other structural unit, 20 mol% or less is preferable and 10 mol% or less is more preferable.

The radiation sensitive resin composition may contain one or more [A] polymers. [A] The content of the polymer is preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 85% by mass or more with respect to the total solid content of the radiation-sensitive resin composition.

<[A] Polymer Synthesis Method>
[A] The polymer can be produced, for example, by polymerizing a monomer corresponding to each predetermined structural unit in a suitable polymerization reaction solvent using a polymerization initiator such as a radical polymerization initiator. For example, a method of dropping a solution containing a monomer and a radical polymerization initiator into a polymerization reaction solvent or a solution containing a monomer to cause a polymerization reaction, a solution containing the monomer, and a radical polymerization initiator A solution containing a polymerization reaction solvent or a monomer-containing solution by dropping each of the contained solutions separately, a plurality of types of solutions containing each monomer, and a solution containing a radical polymerization initiator It is preferable to synthesize | combine by methods, such as the method of dripping into the solution containing a polymerization reaction solvent or a monomer, and making it superpose | polymerize separately.

Examples of the polymerization reaction solvent include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane and n-decane;
Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane;
Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene;
Halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene;
Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate and methyl propionate;
Ketones such as acetone, 2-butanone, 4-methyl-2-pentanone, 2-heptanone;
Ethers such as tetrahydrofuran, dimethoxyethanes, diethoxyethanes;
Examples thereof include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol. These polymerization reaction solvents may be used alone or in combination of two or more.

The reaction temperature in the polymerization may be appropriately determined according to the type of radical initiator, but is usually 40 ° C to 150 ° C, preferably 50 ° C to 120 ° C. The reaction time is usually 1 hour to 48 hours, preferably 1 hour to 24 hours.

Examples of the radical polymerization initiator include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropylene). Pionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylpropionitrile) and the like. These radical polymerization initiators may be used alone or in combination of two or more.

The polymer obtained by the polymerization reaction is preferably recovered by a reprecipitation method. That is, after completion of the polymerization reaction, the polymer is recovered as a powder by introducing the polymerization solution into a reprecipitation solvent. As the reprecipitation solvent, alcohols, alkanes and the like can be used singly or in combination of two or more. In addition to the reprecipitation method, the polymer can be recovered by removing low-molecular components such as monomers and oligomers by a liquid separation operation, a column operation, an ultrafiltration operation, or the like.

[A] The weight average molecular weight (Mw) of the polymer by gel permeation chromatography (GPC) is preferably 1,000 to 100,000, more preferably 1,000 to 30,000, and 2,000 to 20 Is more preferable, and 3,000 to 10,000 is particularly preferable. [A] By making Mw of a polymer into the said range, the resolution, LWR performance, and defect inhibitory property of the said radiation sensitive resin composition can be improved more.

[A] The ratio (Mw / Mn) between the Mw and the number average molecular weight (Mn) of the polymer is usually 1 to 5, preferably 1 to 3, more preferably 1 to 2, more preferably 1.2 to 1. .7 is more preferred. By setting Mw / Mn within the above range, the resolution, LWR performance, and defect suppression of the radiation-sensitive resin composition can be further improved.

In this specification, Mw and Mn are GPC columns (two "G2000HXL", one "G3000HXL", one "G4000HXL" manufactured by Tosoh Corporation), a flow rate of 1.0 mL / min, an elution solvent: tetrahydrofuran, A value measured by GPC using a differential refractometer as a detector and using a monodisperse polystyrene as a standard under the analysis conditions of sample concentration: 1.0 mass%, sample injection amount: 100 μL, column temperature: 40 ° C.

<[B] Acid generator>
[B] The acid generator is a compound that generates an acid upon irradiation with exposure light. The acid-dissociable group in the [A] polymer is dissociated by the action of the acid to generate a polar group such as a carboxy group, and as a result, the solubility of the [A] polymer in the developer changes. [B] The acid generator may be contained in the form of a compound as described later (hereinafter also referred to as “[B] acid generator” as appropriate), or in a form incorporated as part of a polymer. Both forms are acceptable.

[B] Examples of the acid generator include onium salt compounds, N-sulfonyloxyimide compounds, halogen-containing compounds, diazoketone compounds, and the like.

Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.

Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2. 1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate, tri Phenylsulfonium adamantane-1-yloxycarbonyldifluoromethanesulfonate, triphenylsulfonium 2- (adamantan-1-yl) -1,1-difluoroethane-1-sulfonate, triphenylsulfonium 6- (adap N-yl-1-ylcarbonyloxy) -1,1,2,2-tetrafluorohexane-1-sulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfo Nato, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4- Tansulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate Etc.

Examples of the tetrahydrothiophenium salt include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophene. Nitronafluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) ) Tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydro Thiophenium trifluoromethanesulfonate, 1- (6-n-butoxynaphthalene) 2-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (6-n -Butoxynaphthalen-2-yl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl -4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (3,5-dimethyl -4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octa Sulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethane sulfonate, etc. Is mentioned.

Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, and bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate. Bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2 -Bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate and the like.

Of these, onium salts are preferred, sulfonium salts and tetrahydrothiophenium salts are more preferred, sulfonium salts are more preferred, triphenylsulfonium salts are particularly preferred, and triphenylsulfonium adamantane-1-yloxycarbonyldifluoromethanesulfonate. Triphenylsulfonium 2- (adamantan-1-yl) -1,1-difluoroethane-1-sulfonate, triphenylsulfonium 6- (adamantyl-1-ylcarbonyloxy) -1,1,2,2-tetrafluorohexane -1-Sulphonate is more particularly preferred.

[B] Acid generators may be used alone or in combination of two or more. [B] The content when the acid generator is a [B] acid generator is from the viewpoint of improving the sensitivity and developability of the radiation-sensitive resin composition with respect to 100 parts by mass of the [A] polymer. 0.1 to 30 parts by mass is preferable, 0.5 to 20 parts by mass is more preferable, 1 to 15 parts by mass is further preferable, and 3 to 15 parts by mass is more preferable. Particularly preferred. [B] If the content of the acid generator is less than 0.1 parts by mass, the sensitivity tends to be insufficient. On the other hand, if it exceeds 30 parts by mass, the transparency of the resist film to the radiation may decrease.

<[C] Acid diffusion controller>
[C] The acid diffusion controller is a component that controls the diffusion phenomenon of the acid generated from the [B] acid generator upon exposure in the resist film and suppresses an undesirable chemical reaction in the unexposed area. When the radiation-sensitive resin composition contains a [C] acid diffusion controller, the resolution of the resulting radiation-sensitive resin composition is improved, storage stability is improved, and further, from exposure to development processing. Thus, a change in the line width of the resist pattern due to fluctuations in the holding time until the time can be suppressed, and a radiation-sensitive resin composition having extremely excellent process stability can be obtained. In addition, as the inclusion form of the [C] acid diffusion controller, in the form of a free compound (hereinafter also referred to as “[C] acid diffusion controller” as appropriate), or in a form incorporated as part of the polymer, Both of these forms may be used.

[C] Examples of the acid diffusion controller include amine compounds, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

Examples of the amine compound include mono (cyclo) alkylamines; di (cyclo) alkylamines; tri (cyclo) alkylamines; substituted alkylanilines such as 2,6-diisopropylaniline or derivatives thereof; ethylenediamine, N, N , N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) Propane, 2- (4-aminophenyl) -2- (4 Hydroxyphenyl) propane, 1,4-bis (1- (4-aminophenyl) -1-methylethyl) benzene, 1,3-bis (1- (4-aminophenyl) -1-methylethyl) benzene, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″ N ″ -pentamethyldiethylenetriamine, triethanolamine and the like can be mentioned.

Examples of the amide group-containing compound include Nt-butoxycarbonyl group-containing amino compounds such as t-butyl-4-hydroxy-1-piperidinecarboxylate, and t-amyl-4-hydroxy-1-piperidinecarboxylate. Nt-amyloxycarbonyl group-containing amino compound, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methyl Examples include pyrrolidone, N-acetyl-1-adamantylamine, and isocyanuric acid tris (2-hydroxyethyl).

Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea, etc. Is mentioned.

Examples of the nitrogen-containing heterocyclic compound include imidazoles; pyridines; piperazines; pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, 4-hydroxy-N-amyloxycarbonylpiperidine, piperidineethanol, 3-piperidino- 1,2-propanediol; morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, N- (2-cyclohexylcarbonyloxyethyl) morpholine, 3- (N-morpholino) -1, Morpholines such as 2-propanediol; 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like.

Of these, amine compounds and amide group-containing compounds are preferable, substituted alkylanilines and Nt-amyloxycarbonyl group-containing compounds are more preferable, t-amyl-4-hydroxy-1-piperidinecarboxylate, 2,6 -Diisopropylaniline is more preferred.

Further, as the [C] acid diffusion control agent, a photodegradable base that generates a weak acid by exposure can also be used. The photodegradable base exhibits an acid capturing function by an anion in an unexposed area and functions as a quencher, and captures an acid diffused from the exposed area. On the other hand, in the exposed area, an acid is generated and the anion disappears, so that the acid capturing function is lost. That is, since it functions as a quencher only in the unexposed area, the contrast of the dissociation reaction of the acid dissociable group is improved, and as a result, the lithography performance such as the resolution of the radiation sensitive resin composition can be further improved. . Examples of the photodegradable base include an onium salt compound that decomposes upon exposure and loses acid diffusion controllability. Examples of the onium salt compound include a sulfonium salt compound represented by the following formula (C1) and an iodonium salt compound represented by the following formula (C2).

In the formula (C1) and the formula ^{^{(C2), R 20 ~ R}} 24 are each independently a hydrogen atom, an alkyl group, an alkoxy group, hydroxy group, a halogen atom or _-SO 2 -R ^A. R ^A is an alkyl group, a cycloalkyl group, an alkoxy group or an aryl group. Q ⁻ and E ⁻ are OH ⁻ , R ^B —COO ⁻ , R ^C —SO ₂ —N ^— —R ^B , R ^B —SO ₃ ^—, or an anion represented by the following formula (C3). R ^B is a linear or branched alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms. Some or all of the hydrogen atoms of the alkyl group, cycloalkyl group, aryl group and aralkyl group may be substituted. R ^C is a linear or branched alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms of the alkyl group and cycloalkyl group may be substituted with fluorine atoms. However, when Q ⁻ is R ^B —SO ₃ ^— , a fluorine atom is not bonded to a carbon atom to which SO ₃ ^— is bonded.

In the above formula (C3), R ²⁵ represents a linear or branched alkyl group having 1 to 12 carbon atoms in which part or all of the hydrogen atoms may be substituted with fluorine atoms, or 1 to 12 carbon atoms. These are linear or branched alkoxy groups. u is an integer of 0-2.

The ^R 20 ^{~ R 24} in the formula (C1) and (C2), hydrogen atom, _-SO 2 -R ^A is preferred. Moreover, as said ^RA , a cycloalkyl group is preferable and a cyclohexyl group is more preferable.

The alkyl group represented by R ^B, for example a methyl group, an ethyl group, a propyl group, i- propyl group, butyl group, i- butyl group, a t- butyl group and the like, and one hydrogen atom of these groups Examples include groups in which part or all are substituted.

Examples of the cycloalkyl group represented by R ^B include, for example, a cyclopentyl group, a cyclohexyl group, a norbornyl group, a tricyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, etc., and a part of hydrogen atoms of these groups or Examples include groups in which all are substituted.

Examples of the aryl group represented by R ^B, for example, a phenyl group, a naphthyl group, anthranyl group, and some or all of the hydrogen atoms of these groups and the like groups substituted.

Examples of the aralkyl group represented by R ^B include a benzyl group, a phenylethyl group, a phenylpropyl group, and a group in which some or all of the hydrogen atoms of these groups are substituted.

Examples of the substituent that the alkyl group, cycloalkyl group, aryl group, and alkaryl group have include a hydroxy group, a halogen atom, an alkoxy group, a lactone group, and an alkylcarbonyl group.

Examples of the alkyl group represented by R ^C include a methyl group, an ethyl group, a propyl group, and a butyl group.

Examples of the cycloalkyl group represented by R ^C include a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.

Examples of the photodegradable base include compounds represented by the following formulas.

Among these, triphenylsulfonium salicylate and triphenylsulfonium camphorsulfonate are preferable, and triphenylsulfonium camphorsulfonate is more preferable.

[C] The content of the acid diffusion controller is preferably 10 parts by mass or less with respect to 100 parts by mass of the polymer [A] when the [C] acid diffusion controller is a [C] acid diffusion controller. 0.1 parts by mass to 7 parts by mass is more preferable, and 0.3 parts by mass to 5 parts by mass is even more preferable. [C] If the content of the acid diffusion controller exceeds the above upper limit, the sensitivity of the resulting radiation-sensitive resin composition may decrease. [C] The acid diffusion controller may be used alone or in combination of two or more.

<[D] Fluorine atom-containing polymer>
The radiation-sensitive resin composition may further contain, for example, [D] a fluorine atom-containing polymer (excluding those corresponding to the [A] polymer) when used for immersion exposure. . The radiation-sensitive resin composition contains [D] a fluorine atom-containing polymer, so that when the resist film is formed, the distribution of the resist is changed depending on the oil-repellent characteristics of the [D] fluorine atom-containing polymer. Since there is a tendency to be unevenly distributed in the surface layer of the film, elution to the immersion medium such as the [B] acid generator and the [C] acid diffusion controller in the resist film can be suppressed during the immersion exposure. Further, since the radiation sensitive resin composition contains [D] fluorine atom-containing polymer, the receding contact angle of the resist film surface to be formed is increased, so that immersion exposure can be suitably performed, and high-speed scanning is performed. Is possible.

[D] The fluorine atom content of the fluorine atom-containing polymer is preferably higher than the fluorine atom content of the [A] polymer. [D] Since the fluorine atom-containing polymer has a higher fluorine atom content than the [A] polymer, it can be effectively unevenly distributed in the surface layer of the resist film on which the [D] fluorine atom-containing polymer is formed. As a result, the above-described effects at the time of immersion exposure can be further exhibited. [D] The fluorine atom content of the fluorine atom-containing polymer is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass or more. The fluorine atom content (% by mass) of the polymer can be calculated from the result of obtaining the structure of the polymer by ¹³ C-NMR.

[D] The fluorine atom-containing polymer can be usually formed by polymerizing a polymerizable compound containing at least one monomer containing a fluorine atom in its structure.
[D] The fluorine atom-containing polymer preferably has the following structural unit (FI) as the structural unit containing a fluorine atom.

[Structural unit (FI)]
The structural unit (FI) is a structural unit represented by the following formula (F1).

In the above formula (F1), R ²⁶ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ²⁷ is an alkyl group having 1 to 6 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms having at least one fluorine atom, or a derivative thereof. A is a single bond or a divalent linking group.

Examples of the alkyl group having 1 to 6 carbon atoms and having at least one fluorine atom represented by R ²⁷ include, for example, a fluoromethyl group, a difluoromethyl group, a perfluoromethyl group, a difluoroethyl group, a trifluoroethyl group, Examples thereof include a perfluoroethyl group, a trifluoro-n-propyl group, a pentafluoro-n-propyl group, a hexafluoro-i-propyl group, a difluoro-sec-butyl group, and a trifluoro-sec-butyl group.

Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms and having at least one fluorine atom represented by R ²⁷ include a fluorocyclopropyl group, a fluorocyclobutyl group, a fluorocyclopentyl group, a difluoro Examples include a cyclopentyl group, a tetrafluorocyclopentyl group, a perfluorocyclopentyl group, a difluorocyclohexyl group, a perfluorocyclohexyl group, and the like.

As the derivative group for the alkyl group or monovalent alicyclic hydrocarbon group represented by R ²⁷ , for example, the hydrogen atom or fluorine atom of the alkyl group or monovalent alicyclic hydrocarbon group is alkali-dissociated. And a group substituted with a group containing a functional group. The “alkali dissociable group” is a group that replaces a hydrogen atom of a polar group such as a hydroxy group or a carboxy group, for example, in the presence of an alkali (for example, 2.38 mass% tetramethylammonium hydroxy at 23 ° C. Group that dissociates in aqueous solution). Examples of the group containing an alkali dissociable group include —COOR ′ (R ′ is an alkyl group having 1 to 6 carbon atoms).

Examples of the divalent linking group represented by A include alkanediyl groups such as oxygen atom, sulfur atom, carbonyloxy group, oxycarbonyl group, amide group, sulfonylimide group, urethane group, and methanediyl group, and cyclopentane. A divalent alicyclic hydrocarbon group such as a diyl group, a divalent aromatic hydrocarbon group such as a benzenediyl group or a naphthalenediyl group, a divalent group containing a lactone structure such as a norbornanelactone diyl group, or the like And a combination of one or more of the above.

Preferred monomers that give the structural unit (FI) include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylic. Acid ester, perfluoro n-propyl (meth) acrylic acid ester, perfluoro i-propyl (meth) acrylic acid ester, perfluoro n-butyl (meth) acrylic acid ester, perfluoro i-butyl (meth) acrylic acid ester Perfluoro t-butyl (meth) acrylate, 2- (1,1,1,3,3,3-hexafluoropropyl) (meth) acrylate, 1- (2,2,3,3, 4,4,5,5-octafluoropentyl) (meth) acrylic acid ester, perfluorocyclohexylmethyl ( T) Acrylic acid ester, 1- (2,2,3,3,3-pentafluoropropyl) (meth) acrylic acid ester, 1- (3,3,4,4,5,5,6,6,7) , 7,8,8,9,9,10,10,10-heptadecafluorodecyl) (meth) acrylic acid ester, 1- (5-trifluoromethyl-3,3,4,4,5,6, 6,6-octafluorohexyl) (meth) acrylic acid ester, 2,2,2-trifluoroethoxycarbonylmethyl (meth) acrylic acid ester, 1-ethoxycarbonyl-1,1-difluoro-2-butyl (meth) Acrylic acid ester, 2,2,2-trifluoroethoxycarbonylnorbornane lactonyl (meth) acrylic acid ester, 2- (2,2,2-trifluoroethoxycarbonylmethyloxy)- - vinyl naphthalene.

The content ratio of the structural unit (FI) is preferably 5 mol% to 100 mol%, more preferably 10 mol% to 80 mol%, based on all the structural units constituting the [D] fluorine atom-containing polymer. It is preferably 15 mol% to 60 mol%, more preferably 20 mol% to 40 mol%. When the content ratio of the structural unit (FI) is less than the above lower limit, the receding contact angle of the resist film surface formed from the radiation-sensitive resin composition may be less than 70 °. May cause inconveniences such as inability to suppress elution of acid generators.

[Other structural units]
[D] The fluorine atom-containing polymer may have a structural unit other than the structural unit (FI). [D] The fluorine atom-containing compound may have one or more of these structural units.

As the other structural unit, for example, a structural unit containing at least one selected from the group consisting of a structural unit having an acid dissociable group, a lactone structure, a cyclic carbonate structure, and a sultone structure in order to control the dissolution rate in a developer. One or more kinds of structural units derived from an aromatic compound can be contained in order to suppress scattering of light due to reflection from the substrate, structural units containing polar groups, alicyclic groups, and the like.

Examples of the structural unit having an acid dissociable group include the same structural unit as the structural unit (III) of the polymer [A].
Examples of the structural unit containing at least one structure selected from the group consisting of the lactone structure, the cyclic carbonate structure, and the sultone structure include the same structural units as the structural unit (II) of the polymer [A]. .
As a structural unit containing the said polar group, the structural unit etc. similar to the structural unit (IV) of a [A] polymer are mentioned, for example.

The content ratio of the other structural units is usually 80 mol% or less, preferably 75 mol% or less.

[D] The content of the fluorine atom-containing polymer is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the [A] polymer. 1 to 10 parts by mass is more preferable.

<[D] Method for Synthesizing Fluorine Atom-Containing Polymer>
[D] A fluorine atom containing polymer is compoundable using the method similar to the synthesis method of the above-mentioned [A] polymer.

[D] The Mw of the fluorine atom-containing polymer is preferably 1,000 to 50,000, more preferably 3,000 to 30,000, and still more preferably 5,000 to 20,000. [D] When Mw of the fluorine atom-containing polymer is less than the lower limit, the formed resist film surface may not be able to obtain a sufficient advancing contact angle. On the other hand, when Mw exceeds the above upper limit, the developability of the resulting radiation-sensitive resin composition tends to decrease.

[D] The Mw / Mn ratio of the fluorine atom-containing polymer is usually 1 to 3, preferably 1 to 2.5, and more preferably 1 to 2.

<[E] solvent>
The radiation-sensitive resin composition usually contains an [E] solvent. [E] Solvent is at least [A] polymer, [B] acid generator, [C] acid diffusion controller contained as needed, [D] fluorine atom-containing polymer, and other optional components described later If it can melt | dissolve or disperse | distribute, it will not specifically limit. [E] Examples of the solvent include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents, and the like.

As an alcohol solvent, for example,
Methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert- Pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n- Nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, furf Alcohol, phenol, cyclohexanol, methyl cyclohexanol, 3,3,5-trimethyl cyclohexanol, benzyl alcohol, mono-alcohol solvents such as diacetone alcohol;
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2 Polyhydric alcohol solvents such as ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol Monomethyl ether, dipropylene glycol monoethyl ether, polyhydric alcohol partial ether solvents such as dipropylene glycol monopropyl ether.

As an ether solvent, for example,
Dialiphatic ether solvents such as diethyl ether, dipropyl ether, dibutyl ether;
Aromatic ring ether solvents such as anisole and diphenyl ether;
Examples thereof include cyclic ether solvents such as tetrahydrofuran and dioxane.

Examples of ketone solvents include:
Acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl-n-amyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-iso-butyl ketone Chain ketone solvents such as trimethylnonanone and acetophenone;
Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methylcyclohexanone;
And diketone solvents such as 2,4-pentanedione and acetonylacetone.

Examples of the amide solvent include
Chain amide solvents such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide;
And cyclic amide solvents such as N-methylpyrrolidone and N, N′-dimethylimidazolidinone.

Examples of ester solvents include:
Methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl pentyl acetate 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n propionate -Butyl, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate, etc. Carboxylate solvent;
Acetic acid ethylene glycol monomethyl ether, acetic acid ethylene glycol monoethyl ether, acetic acid diethylene glycol monomethyl ether, acetic acid diethylene glycol monoethyl ether, acetic acid diethylene glycol mono-n-butyl ether, acetic acid propylene glycol monomethyl ether, acetic acid propylene glycol monoethyl ether, acetic acid propylene glycol monopropyl ether Carboxylic acid ester solvents of polyhydric alcohol partial ethers such as ether, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate;
Examples thereof include carbonate solvents such as diethyl carbonate.

Examples of the hydrocarbon solvent include
Aliphatic carbonization such as n-pentane, iso-pentane, n-hexane, iso-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane, iso-octane, cyclohexane, methylcyclohexane A hydrogen-based solvent;
Fragrances such as benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, iso-propylbenzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di-iso-propylbenzene, n-amylnaphthalene Group hydrocarbon solvents and the like.

Among these, ester solvents and ketone solvents are preferable, carboxylic acid ester solvents of polyhydric alcohol partial ethers, cyclic ketone solvents are more preferable, propylene glycol monoalkyl ether acetates and cycloalkanones are more preferable, acetic acid Propylene glycol monomethyl ether and cyclohexanone are particularly preferred. [E] A solvent can be used individually by 1 type or in mixture of 2 or more types.

<Other optional components>
In addition to the above components [A] to [E], the radiation-sensitive resin composition contains an uneven distribution accelerator, a surfactant, an alicyclic skeleton-containing compound, a sensitizer and the like as other optional components. it can. In addition, the said radiation sensitive resin composition may contain another arbitrary component individually by 1 type or in mixture of 2 or more types, respectively.

[Uneven distribution promoter]
The uneven distribution accelerator has an effect of segregating the [D] polymer on the resist film surface more efficiently when the radiation-sensitive resin composition contains the [D] polymer. By including this uneven distribution accelerator in the radiation sensitive resin composition, the amount of the [D] polymer added can be reduced as compared with the conventional case. Therefore, it is possible to further suppress the elution of components from the resist film to the immersion liquid without impairing the resolution, LWR performance, and defect suppression, or to perform immersion exposure at a higher speed by high-speed scanning. As a result, it is possible to improve the hydrophobicity of the resist film surface that suppresses immersion-derived defects such as watermark defects. Examples of such an uneven distribution promoter include low molecular compounds having a relative dielectric constant of 30 or more and 200 or less and a boiling point at 1 atm of 100 ° C. or more. Specific examples of such compounds include lactone compounds, carbonate compounds, nitrile compounds, and polyhydric alcohols.

Examples of the lactone compound include γ-butyrolactone, valerolactone, mevalonic lactone, and norbornane lactone.
Examples of the carbonate compound include propylene carbonate, ethylene carbonate, butylene carbonate, vinylene carbonate, and the like.
Examples of the nitrile compound include succinonitrile.
Examples of the polyhydric alcohol include glycerin.

The content of the uneven distribution accelerator is preferably 10 parts by weight to 500 parts by weight, more preferably 15 parts by weight to 300 parts by weight with respect to 100 parts by weight of the total amount of the polymer in the radiation sensitive resin composition. 20 parts by mass to 200 parts by mass is more preferable, and 25 parts by mass to 100 parts by mass is particularly preferable.

[Surfactant]
The surfactant exhibits the effect of improving the coating property, striation, developability and the like of the radiation sensitive resin composition. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol diacrylate. Nonionic surfactants such as stearate, commercially available products such as KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, Kyoeisha Chemical Co., Ltd.), F-Top EF301, EF303, EF352 (above, Tochem Products), MegaFuck F171, F173 (above, Dainippon Ink and Chemicals), Florard FC430, FC431 ( Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (above, Asahi Glass Industry) Company).

[Alicyclic skeleton-containing compound]
The alicyclic skeleton-containing compound has an effect of improving the dry etching resistance, pattern shape, adhesion to the substrate, and the like of the radiation-sensitive resin composition.

Examples of the alicyclic skeleton-containing compound include adamantane derivatives such as 1-adamantanecarboxylic acid, 2-adamantanone, and 1-adamantanecarboxylic acid t-butyl;
Deoxycholic acid esters such as t-butyl deoxycholic acid, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid;
Lithocholic acid esters such as tert-butyl lithocholic acid, tert-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid;
3- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, 2-hydroxy-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nonane, and the like.

[Sensitizer]
A sensitizer exhibits the effect | action which increases the production amount of the acid from a [B] acid generator, and there exists an effect which improves the "apparent sensitivity" of the said radiation sensitive resin composition.

Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like.

<Method for preparing radiation-sensitive resin composition>
The radiation sensitive resin composition includes, for example, an [A] polymer, a [B] acid generator, an [C] acid diffusion controller, and [D] a fluorine atom-containing heavy agent in a [E] solvent. It can be prepared by mixing the coalesced and other optional components at a predetermined ratio. The prepared radiation-sensitive resin composition is preferably filtered and used, for example, with a filter having a pore diameter of 20 nm. The solid content concentration of the radiation-sensitive resin composition is preferably 0.1% by mass to 50% by mass, more preferably 0.5% by mass to 30% by mass, and further preferably 1% by mass to 15% by mass. 1% by mass to 10% by mass is particularly preferable.

<Resist pattern formation method>
The resist pattern forming method of the present invention comprises:
A step of forming a resist film (hereinafter also referred to as a “resist film forming step”),
A step of exposing the resist film (hereinafter also referred to as “exposure step”), and a step of developing the exposed resist film (hereinafter also referred to as “development step”).
With
The resist film is formed from the radiation sensitive resin composition.
Hereinafter, each step will be described.

[Resist film forming step]
In this step, a resist film is formed from the radiation sensitive resin composition. As a substrate on which the resist film is formed, a conventionally known substrate such as a silicon wafer or a wafer coated with aluminum can be used. Further, for example, an organic or inorganic antireflection film disclosed in Japanese Patent Publication No. 6-12452 and Japanese Patent Application Laid-Open No. 59-93448 may be formed on the substrate.

Examples of the application method include spin coating, spin coating, roll coating, and the like. The film thickness of the formed resist film is preferably 10 nm to 1,000 nm, and more preferably 10 nm to 500 nm.

After applying the radiation sensitive resin composition, the solvent in the coating film may be volatilized by pre-baking (PB) as necessary. The PB temperature is appropriately selected depending on the composition of the radiation sensitive resin composition, but is usually 30 ° C. to 200 ° C., preferably 50 ° C. to 150 ° C. The PB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 300 seconds.

In order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film disclosed in, for example, Japanese Patent Laid-Open No. 5-188598 can be provided on the resist film. Further, in order to prevent the acid generator and the like from flowing out from the resist film, a liquid immersion protective film disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-352384 can be provided on the resist film. These techniques can be used in combination.

[Exposure process]
In this step, the resist film formed in the resist film forming step is exposed. As this exposure, for example, an isotrench pattern can be formed by performing reduced projection exposure on a desired region through an isoline pattern mask. Moreover, you may perform exposure twice or more with a desired pattern and a mask pattern. When performing exposure twice or more, it is preferable to perform exposure continuously. In the case of performing multiple exposures, for example, a first reduced projection exposure is performed on a desired area via a line and space pattern mask, and then the second is so that the line intersects the exposed portion where the first exposure has been performed. Reduced projection exposure is performed. The first exposure part and the second exposure part are preferably orthogonal. By being orthogonal, it becomes easy to form a perfect circular contact hole pattern in the unexposed area surrounded by the exposed area. Examples of the immersion liquid used for exposure include water and a fluorine-based inert liquid. The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient that is as small as possible so as to minimize distortion of the optical image projected onto the film. In the case of excimer laser light (wavelength 193 nm), it is preferable to use water from the viewpoints of availability and easy handling in addition to the above-described viewpoints. When water is used, an additive that decreases the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the resist layer on the wafer and can ignore the influence on the optical coating on the lower surface of the lens. The water used is preferably distilled water.

The radiation used for the exposure is appropriately selected according to the type of the [B] acid generator. For example, electromagnetic waves such as ultraviolet rays, far ultraviolet rays, visible rays, X rays, γ rays; electron rays, α rays And charged particle beams. Among these, far ultraviolet rays are preferable, ArF excimer laser light and KrF excimer laser light (wavelength 248 nm) are more preferable, and ArF excimer laser is more preferable. The exposure conditions such as the exposure amount are appropriately selected according to the blending composition of the radiation-sensitive resin composition, the type of additive, and the like. In the pattern formation method, the exposure process may be performed a plurality of times, and the same light source or different light sources may be used for the plurality of exposures, but ArF excimer laser light is used for the first exposure. Is preferred.

Moreover, it is preferable to perform post-exposure baking (PEB) after exposure. By performing PEB, the dissociation reaction of the acid dissociable group in the radiation sensitive resin composition can proceed smoothly. The PEB temperature is usually 30 ° C. to 200 ° C., preferably 50 ° C. to 170 ° C., and more preferably 70 ° C. to 120 ° C. The PEB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 300 seconds.

[Development process]
In this step, the resist film exposed in the exposure step is developed. Thereby, a resist pattern is obtained.

In this step, either alkali development or organic solvent development may be used. In general, an exposed portion is removed by alkali development to form a positive resist pattern, and an unexposed portion is removed by organic solvent development to form a negative resist pattern. According to organic solvent development, a resist pattern having a smaller LWR can be formed.

As the developer used in this step,
For alkali development, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine , Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, and 1,5-diazabicyclo- [ 4.3.0] -5-nonene and an alkaline aqueous solution in which at least one selected from the group consisting of alkaline compounds is dissolved. The concentration of the alkaline aqueous solution is preferably 10% by mass or less. When the concentration of the alkaline aqueous solution exceeds 10% by mass, the unexposed area may be dissolved in the developer. An organic solvent can also be added to the alkaline aqueous solution.
In the case of organic solvent development, examples of the developer include one or more of the solvents exemplified as the [E] solvent of the above-described radiation-sensitive resin composition. As content of the organic solvent in a developing solution, 80 mass% or more is preferable, 90 mass% or more is more preferable, 95 mass% or more is further more preferable.

An appropriate amount of a surfactant can be added to the developer as necessary. As the surfactant, for example, an ionic or nonionic fluorine-based and / or silicon-based surfactant can be used.

As a developing method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle method) ), A method of spraying the developer on the substrate surface (spray method), a method of continuously applying the developer while scanning the developer coating nozzle on the substrate rotating at a constant speed (dynamic dispensing method) Etc.

It is preferable to wash the formed resist pattern with a rinse solution after the development. As the rinse solution, water is preferable in the case of alkali development, and pure water is more preferable. In the case of organic solvent development, alcohol solvents and ester solvents are preferable, monovalent alcohol solvents having 6 to 8 carbon atoms are more preferable, and 1-hexanol, 2-hexanol, 2-heptanol, 4-methyl-2 -Pentanol is more preferred.

As a cleaning method, for example, a method of continuously applying a rinse liquid onto a substrate rotating at a constant speed (rotary coating method), a method of immersing the substrate in a tank filled with the rinse liquid for a predetermined time (dip method) ), A method (spray method) of spraying a rinse liquid on the substrate surface, and the like.

<Polymer>
The polymer of this invention has a structural unit containing group represented by the said Formula (1). Since the said polymer has the said specific structural unit, it can be conveniently used as a polymer component of the said radiation sensitive resin composition mentioned above.

<Compound>
The compound of the present invention is represented by the above formula (i). Since the said compound has the said specific structure, it can be conveniently used as a monomer which gives the structural unit (I) of the said polymer mentioned above.

The polymer and the compound are described in the [A] polymer section of the radiation-sensitive resin composition described above.

Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to the examples. The measuring method of various physical property values is shown below.

[Mw and Mn measurement]
Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) under the following conditions.
Column: 2 Tosoh "G2000HXL", 1 "G3000HXL" and 1 "G4000HXL" Eluent: Tetrahydrofuran Column temperature: 40 ° C
Flow rate: 1.0 mL / min Detector: Differential refractometer Standard material: Monodisperse polystyrene

[ ¹³ C-NMR analysis]
The ¹³ C-NMR analysis for determining the content of each structural unit in the polymer was measured using a nuclear magnetic resonance apparatus (“JNM-ECX400” manufactured by JEOL Ltd.).

[Example 1]
A 1 L eggplant flask was charged with 17.0 g (260 mmol) of zinc powder and 160 mL of THF, and 1 g (9.1 mmol) of trimethylsilyl chloride was slowly added dropwise. After completion of the addition, the mixture was stirred at room temperature for 30 minutes. This solution was heated to reflux, and a mixed solution of 25.0 g (260 mmol) of 2-cyclohexen-1-one, 42.9 g (260 mmol) of α-bromo-γ-butyrolactone and 160 mL of THF was slowly added dropwise thereto. After completion of the dropwise addition, the mixture was stirred for 4 hours under reflux conditions. After the temperature was lowered to room temperature, 170 g of 20% by mass acetic acid aqueous solution was added to stop the reaction. The obtained reaction product was subjected to extraction washing and column chromatography purification to obtain 24 g of a compound represented by the following formula (ib-1) (yield 50%).

Next, in a 1 L eggplant flask, 24 g (130 mmol) of the compound (ib-1) obtained above, 13 g (130 mmol) of triethylamine, 4.4 g (39 mmol) of 1,4-diazabicyclo [2.2.2] octane were obtained. ) And 100 mL of acetonitrile, and cooled to 0 ° C. in an ice bath. Thereto, 16 g (156 mmol) of methacryloyl chloride was slowly added dropwise. After completion of the dropping, the mixture was stirred at 0 ° C. for 30 minutes and then at 45 ° C. for 4 hours, and then the reaction was stopped by adding a 3.75 mass% aqueous sodium hydrogen carbonate solution. The resulting reaction product was subjected to extraction washing and column chromatography purification to obtain 15 g of a compound represented by the following formula (i-1) (yield 46%, total yield 23%).

[Example 2]
In Example 1, the same procedure as in Example 1 was carried out except that methyl bromoacetate was used instead of α-bromo-γ-butyrolactone as a starting material. 15 g of compound was obtained (total yield 25%).

[Example 3]
In Example 1, except that 2-cyclopenten-1-one was used instead of 2-cyclohexen-1-one as a starting material, the same operation as in Example 1 was carried out to obtain the following formula (i-3) 14 g of the compound represented was obtained (total yield 22%).

[Example 4]
In Example 2, except that 2-cyclopenten-1-one was used instead of 2-cyclohexen-1-one as a starting material, the same operation as in Example 2 was carried out to obtain the following formula (i-4) 16 g of the compound represented was obtained (total yield 28%).

[Example 5]
In Example 1, except that dimethyl bromomalonate was used instead of α-bromo-γ-butyrolactone as a starting material, the same procedure as in Example 1 was performed, and represented by the following formula (i-5) 19 g of compound was obtained (total yield 25%).

<Synthesis of polymer>
The monomers used for the synthesis of [A] polymer and [D] fluorine atom-containing polymer are shown below.

[[A] Synthesis of polymer]
[Example 6]
A monomer solution was prepared by dissolving 10 g (100 mol%) of compound (i-1) in 20 g of 2-butanone and further dissolving 0.32 g of AIBN as a radical polymerization initiator. Next, a 100 mL three-necked flask containing 10 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the monomer solution prepared above was added dropwise over 3 hours using a dropping funnel. . The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was cooled with water and cooled to 30 ° C. or lower. In 200 g of methanol, the cooled polymerization reaction solution was added, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 40 g of methanol, filtered, and dried at 50 ° C. for 17 hours to obtain a white powdery polymer (A-1) (yield 7.6 g, yield). 76%). Mw of the polymer (A-1) was 7,000, and Mw / Mn was 1.5.

[Examples 7 to 13 and Synthesis Examples 1 to 3]
Polymers (A-2) to (A-8) and (CA-1) to (CA) were operated in the same manner as in Example 6 except that the types and amounts of monomers shown in Table 1 were used. -3) was synthesized. The total mass of the monomers used was 10 g. Table 1 shows the content (mol%), yield (%), Mw and Mw / Mn of structural units derived from the respective monomers of the synthesized polymer.

[[D] Synthesis of fluorine atom-containing polymer]
[Synthesis Example 4]
79.9 g (70 mol%) of the compound (M-4) and 20.91 g (30 mol%) of the compound (M-5) were dissolved in 100 g of 2-butanone, and dimethyl 2,2 as radical polymerization initiator was dissolved. A monomer solution was prepared by further dissolving 4.77 g of 2′-azobisisobutyrate. Next, a 1,000 mL three-necked flask containing 100 g of 2-butanone was purged with nitrogen for 30 minutes and then heated to 80 ° C. with stirring. The monomer solution prepared above was added to the dropping funnel over 3 hours. It was dripped. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was cooled with water and cooled to 30 ° C. or lower. After the cooled polymerization reaction liquid was transferred to a 2 L separatory funnel, the polymerization reaction liquid was uniformly diluted with 150 g of n-hexane, and 600 g of methanol was added and mixed. Next, 30 g of distilled water was added, and the mixture was further stirred and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to obtain a propylene glycol monomethyl ether acetate solution of polymer (D-1) (yield 60%). Mw of the polymer (D-1) was 7,200, and Mw / Mn was 2.00. As a result of ¹³ C-NMR analysis, the contents of the structural units derived from (M-4) and (M-5) in the polymer (D-1) were 71.1 mol% and 28.9 mol%, respectively. there were.

<Preparation of radiation-sensitive resin composition>
Each component used for preparation of each radiation sensitive resin composition is shown below.

[[B] acid generator]
B-1: Triphenylsulfonium 2- (adamantan-1-yl) -1,1-difluoroethane-1-sulfonate (compound represented by the following formula (B-1))

[[C] acid diffusion controller]
C-1: Triphenylsulfonium salicylate (compound represented by the following formula (C-1))

[[E] solvent]
E-1: Propylene glycol monomethyl ether acetate E-2: Cyclohexanone

[[F] uneven distribution promoter]
F-1: γ-butyrolactone

[Example 14]
[A] 100 parts by mass of (A-1) as a polymer, [B] 8.5 parts by mass of (B-1) as an acid generator, [C] (C-1) 2 as an acid diffusion controller 3 parts by weight, (D-1) 3 parts by weight as a [D] fluorine atom-containing polymer, (E-1) 2,240 parts by weight and (E-2) 960 parts by weight as a solvent [E] In addition, [F] 30 parts by mass of (F-1) as an uneven distribution promoter was mixed, and the obtained mixed solution was filtered through a 20 nm membrane filter to obtain a radiation-sensitive resin composition (J-1). Prepared.

[Examples 15 to 21 and Comparative Examples 1 to 3]
In Example 14, radiation sensitive resin compositions (J-2) to (J-8) and (J-8) were prepared in the same manner as in Example 14 except that the components having the types and contents shown in Table 2 below were used. (CJ-1) to (CJ-3) were prepared.

<Formation of resist pattern (alkali development)>
On the surface of a 12-inch silicon wafer, using a spin coater (“CLEAN TRACK ACT12” manufactured by Tokyo Electron), a composition for forming a lower antireflection film (“ARC66” manufactured by Brewer Science) was applied at 205 ° C. Was heated for 60 seconds to form a lower antireflection film having a thickness of 105 nm. On the lower antireflection film, each radiation sensitive resin composition was applied using the spin coater, and PB was performed at 90 ° C. for 60 seconds. Thereafter, it was cooled at 23 ° C. for 30 seconds to form a resist film having a thickness of 90 nm. Next, this resist film was subjected to an optical condition of NA = 1.3 and dipole (Sigma 0.977 / 0.782) using an ArF excimer laser immersion exposure apparatus (“NSR-S610C” manufactured by NIKON). , Exposed through a 40 nm line and space (1L1S) mask pattern. After the exposure, PEB was performed at 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38 mass% TMAH aqueous solution, washed with water, and dried to form a positive resist pattern. At this time, the exposure amount for forming a 40 nm line and space was determined as the optimum exposure amount (Eop).

<Evaluation>
About each formed resist pattern, each radiation sensitive resin composition was evaluated by measuring with the following method about the following evaluation item. The evaluation results are shown in Table 3. A scanning electron microscope (Hitachi High-Technologies “S-9380”) was used to measure the resist pattern.

[Resolution]
The minimum resist pattern dimension resolved in the above Eop was defined as resolution (nm). The smaller the value, the better the resolution. The resolution can be evaluated as “good” when it is 36 nm or less, and “bad” when it exceeds 36 nm.

[LWR performance]
The resist pattern was observed from above the pattern using the scanning electron microscope. A total of 50 line widths were measured at arbitrary points, and a 3-sigma value was obtained from the distribution of the measured values, and this was defined as LWR performance (nm). LWR performance indicates that the smaller the value, the better. The LWR performance can be evaluated as “good” when it is 3.8 nm or less, and “bad” when it exceeds 3.8 nm.

[Defect suppression]
Each radiation-sensitive resin composition was applied onto a 12-inch silicon wafer on which an underlayer antireflection film was formed with a composition for forming an underlayer antireflection film (“ARC66” from Brewer Science), and PB was applied at 120 ° C. for 60 seconds. By doing so, a resist film having a thickness of 75 nm was formed. Next, for this resist film, an ArF excimer laser immersion exposure apparatus (“NSR-S610C” manufactured by NIKON) was used, and the target size was 45 nm in width under the conditions of NA = 1.3, ratio = 0.750, and Crosssole. The film was exposed through a line and space (1L / 1S) mask pattern. After exposure, PEB was performed at 100 ° C. for 60 seconds. Then, using a developing device (Tokyo Electron's “Clean Track ACT12” GP nozzle, developing with 2.38 mass% TMAH aqueous solution for 30 seconds, rinsing with pure water for 7 seconds, shaking off and drying at 3,000 rpm. In this case, the exposure amount for forming 1 L / 1S having a width of 45 nm was determined as the optimum exposure amount, and 1 L / 1S having a line width of 45 nm was formed on the entire surface of the wafer with this optimum exposure amount. A scanning electron microscope (Hitachi High-Technologies “CC-4000”) was used for length measurement, and the number of defects on the defect inspection wafer was calculated using a defect inspection apparatus. (KLA-Tencor's “KLA2810”), and the measured defects are classified as resist film-derived and externally derived foreign matters. Of these, the total number of defects determined to be derived from the resist film was calculated and used as an index of defect suppression, which is “A” when less than 1,000 / wafer, In the case of 1,000 / wafer or more, it was evaluated as “B”.

<Resist pattern formation (organic solvent development)>
In the formation of the resist pattern (alkali development), the resist pattern was formed (alkaline development) except that the developer was replaced with n-butyl acetate instead of the 2.38 mass% TMAH aqueous solution and the water washing step was eliminated. In the same manner as in the case, a resist pattern was formed and evaluated. The evaluation results are shown in Table 3.

From the results in Table 3, it can be seen that the radiation-sensitive resin compositions of the examples are excellent in resolution, LWR performance and defect suppression in both cases of alkali development and organic solvent development. In the case of both the alkali development and the organic solvent development, the radiation sensitive resin composition of the comparative example was insufficient in resolution, LWR performance, and defect suppression.

Claims

The radiation sensitive resin composition containing the polymer which has a structural unit containing group represented by following formula (1), and a radiation sensitive acid generator.

(In Formula (1), R 1 is a monovalent organic group having 2 to 30 carbon atoms including at least one selected from the group consisting of O, N and S. R 2 includes a double bond. An alicyclic hydrocarbon group having 5 to 20 carbon atoms, wherein R a and R b are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, * represents the above structure Indicates the site that binds to the other part of the unit.)
The radiation sensitive resin composition according to claim 1, wherein the group represented by the formula (1) has acid dissociation properties.
R 1 is at least one selected from the group consisting of —COO—, —CONR′— and —SO— between the carbon and carbon of the alkyl group having 2 to 20 carbon atoms or the cycloalkyl group having 3 to 20 carbon atoms. Or a group (b) in which part or all of the hydrogen atoms of the group (a) are substituted with at least one selected from the group consisting of a cyano group and a hydroxy group, and R ′ is The radiation-sensitive resin composition according to claim 1, which is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.
The radiation-sensitive resin composition according to claim 1, wherein the structural unit is at least one selected from the group consisting of structural units represented by the following formulas (2-1) to (2-3).

(In the formulas (2-1) to (2-3), Z is a group represented by the above formula (1).
In formula (2-1), R 6 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
In formula (2-2), R 7 represents a hydrogen atom or a methyl group. E is a single bond or a divalent linking group. Ar 1 is a substituted or unsubstituted arenediyl group having 6 to 30 carbon atoms.
In formula (2-3), R 8 represents a hydrogen atom or a methyl group. R 9 and R 10 are each independently a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms. Two or more of one or more of R 9 and R 10 may be combined with each other to form a ring structure having 3 to 20 ring members that is configured together with the carbon atom to which they are bonded. m is an integer of 1 to 4. When m is 2 or more, the plurality of R 9 and R 10 may be the same or different. R 11 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. G is a single bond or a divalent linking group. R 11 and G may be combined with each other to form a ring structure with 3 to 20 ring members that is composed of carbon atoms to which they are bonded. )
Forming a resist film;
A step of exposing the resist film, and a step of developing the exposed resist film,
A method for forming a resist pattern, wherein the resist film is formed from the radiation-sensitive resin composition according to claim 1.
The polymer which has a structural unit containing group represented by following formula (1).

(In Formula (1), R 1 is a monovalent organic group having 2 to 30 carbon atoms including at least one selected from the group consisting of O, N and S. R 2 includes a double bond. An alicyclic hydrocarbon group having 5 to 20 carbon atoms, wherein R a and R b are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, * represents the above structure Indicates the site that binds to the other part of the unit.)
A compound represented by the following formula (i).

(In Formula (i), R 1 is a monovalent organic group having 2 to 30 carbon atoms including at least one selected from the group consisting of O, N and S. R 2 includes a double bond. An alicyclic hydrocarbon group having 5 to 20 carbon atoms, R a and R b are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and Y is polymerizable. (It is a monovalent group containing a carbon-carbon double bond.)
The compound according to claim 7, wherein Y in the formula (i) is represented by the following formulas (y-1) to (y-3).

(In the formulas (y-1) to (y-3), * represents a bonding site to the carbon atom to which R 1 in the above formula (i) is bonded.
In formula (y-1), R 6 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
In formula (y-2), R 7 is a hydrogen atom or a methyl group. E is a single bond or a divalent linking group. Ar 1 is a substituted or unsubstituted arenediyl group having 6 to 30 carbon atoms.
In formula (y-3), R 8 represents a hydrogen atom or a methyl group. R 9 and R 10 are each independently a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms. Two or more of one or more of R 9 and R 10 may be combined with each other to form a ring structure having 3 to 20 ring members that is configured together with the carbon atom to which they are bonded. m is an integer of 1 to 4. When m is 2 or more, the plurality of R 9 and R 10 may be the same or different. R 11 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. G is a single bond or a divalent linking group. R 11 and G may be combined with each other to form a ring structure with 3 to 20 ring members that is composed of carbon atoms to which they are bonded. )