JP2004272227A - Negative radiation-sensitive resin composition - Google Patents

Abstract

Ｒ¹は水素原子またはメチル基を表し、式（１−１）において、Ｘ¹およびＸ²は相互に独立に水素原子またはフルオロアルキル基を表し、かつＸ¹およびＸ²の少なくとも１つがフルオロアルキル基を表し、Ｙは２価の有機基を表し、Ｚは２〜４価の有機基を表し、Ｔは単結合または炭素数１〜３の２価の有機基を表し、ｎは１〜３の整数を表す。
【選択図】 無PROBLEM TO BE SOLVED: To show a high resolution in a line-and-space pattern, form a rectangular resist pattern, reduce resist pattern defects such as bridging after development, and improve sensitivity and developability. Also, it has excellent dimensional fidelity.
SOLUTION: The copolymer resin (A) contains a repeating unit (1-1) represented by the following formula (1-1) and a repeating unit (1-2) represented by the following formula (1-2). And a radiation-sensitive acid generator (B) and an acid crosslinking agent (C).
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R ¹ represents a hydrogen atom or a methyl group; in the formula (1-1), X ¹ and X ² independently represent a hydrogen atom or a fluoroalkyl group, and at least one of X ¹ and X ² is a fluoroalkyl Y represents a divalent organic group; Z represents a divalent to tetravalent organic group; T represents a single bond or a divalent organic group having 1 to 3 carbon atoms; Represents an integer.
[Selection diagram] None

Description

  The present invention relates to a negative-type radiation-sensitive resin composition, and particularly uses various radiations such as far-ultraviolet rays such as KrF excimer laser or ArF excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams. The present invention relates to a negative-type radiation-sensitive resin composition that can be suitably used as a chemically amplified resist useful for fine processing.

In field of microfabrication represented by fabrication of integrated circuit devices, in order to achieve a higher degree of integration, ArF excimer laser (wavelength 193 nm) has recently, F ₂ excimer laser (wavelength 157 nm) or less 200nm about using such There is a need for a lithography technology capable of microfabrication at a level. Such a radiation-sensitive resin composition suitable for irradiation with an excimer laser is a chemical composition utilizing a chemical amplification effect of a component having an acid dissociable functional group and an acid generator which is a component that generates an acid upon irradiation with radiation. Many amplification-type radiation-sensitive resin compositions have been proposed. Among the chemically amplified radiation-sensitive resin compositions, the negative-type radiation-sensitive resin composition is formed by causing a crosslinking reaction to proceed in a radiation-irradiated portion, thereby reducing a dissolution rate in a developer and forming a pattern. I have.
Conventionally, as a negative radiation-sensitive resin composition, a chemically amplified negative resist having a (meth) acrylate derivative having a dihydroxy alicyclic group as a crosslinking site has been known (Patent Document 1).
By the way, when actually manufacturing an integrated circuit using a resist, usually, a radiation-sensitive component, a film-forming resin component and the like are dissolved in a solvent to prepare a radiation-sensitive resin composition as a resist solution, After applying the resist solution on a substrate to be processed to form a resist film, the resist film is irradiated with radiation through a predetermined mask and developed, thereby forming a pattern suitable for fine processing. Let it. At that time, the shape of the pattern cross section (pattern cross section shape) has a significant influence on the precision of the fine processing, and a rectangular shape is preferable in order to improve the precision.
JP-A-2000-122288 (paragraph [0022])

  However, the conventional chemically amplified negative resist has a low resolution because the difference in dissolution rate between the irradiated part and the non-irradiated part in the developing solution of the resist is not large enough, and the pattern has There is a problem that the shape is not rectangular but round. Furthermore, since the dissolution rate of the unirradiated part is too high, the dissolution rate of the irradiated part cannot be sufficiently reduced, and there is a problem that the pattern is swollen or meandered by the developer.

  The present invention has been made in order to address such a problem, and can be applied as a negative-type radiation-sensitive resin composition using an ArF light source to a conventional normal-concentration developer without any problem.・ High resolution and rectangular pattern can be formed in the AND space pattern. Resist pattern defects such as bridging after development can be reduced, and sensitivity, developability and dimensional fidelity can be reduced. It is an object of the present invention to provide a negative-type radiation-sensitive resin composition suitable as a chemically amplified negative-type resist having excellent properties.

上記式（１−１）および式（１−２）において、Ｒ¹は水素原子またはメチル基を表し、式（１−１）において、Ｘ¹およびＸ²は相互に独立に水素原子またはフルオロアルキル基を表し、かつＸ¹およびＸ²の少なくとも１つがフルオロアルキル基を表し、Ｙは２価の有機基を表し、Ｚは２〜４価の有機基を表し、Ｔは単結合または炭素数１〜３の２価の有機基を表し、ｎは１〜３の整数を表す。
また、共重合樹脂（Ａ）のゲルパーミエーションクロマトグラフィー（ＧＰＣ）で測定したポリスチレン換算重量平均分子量が１，０００〜５０，０００であることを特徴とする。 The negative-type radiation-sensitive resin composition of the present invention comprises a repeating unit (1-1) represented by the following formula (1-1) and a repeating unit (1-2) represented by the following formula (1-2). , A radiation-sensitive acid generator (B), and an acid crosslinking agent (C).

In the above formulas (1-1) and (1-2), R ¹ represents a hydrogen atom or a methyl group. In the formula (1-1), X ¹ and X ² independently represent a hydrogen atom or a fluoroalkyl group. Represents a group, and at least one of X ¹ and X ² represents a fluoroalkyl group, Y represents a divalent organic group, Z represents a divalent to tetravalent organic group, and T represents a single bond or one carbon atom. Represents a divalent organic group of 3 to 3, and n represents an integer of 1 to 3.
Further, the copolymer resin (A) has a polystyrene equivalent weight average molecular weight of 1,000 to 50,000 as measured by gel permeation chromatography (GPC).

上記式（２−１）、式（２−２）および式（２−３）において、Ｘ⁻は、Ｒ³−ＳＯ₃ ⁻を表し、Ｒ³は、部分的もしくは全てフッ素化されていてもよい、脂肪族炭化水素基または芳香族炭化水素基を表し、Ｒ²は、水素原子、または、脂肪族炭化水素基もしくは芳香族炭化水素基を表し、Ｒ⁴は、部分的もしくは全てフッ素化されていてもよい、脂肪族炭化水素基または芳香族炭化水素基を表し、Ｕは２価の有機基を表し、Ｒ⁵およびＲ⁶は、互いに独立に水素原子、脂肪族炭化水素基、または芳香族炭化水素基を表し、ｍは０〜３の整数を表し、ｎは０〜２の整数を表す。
また、特に感放射線性酸発生剤（Ｂ）が式（２−３）であることを特徴とする。 The negative radiation-sensitive resin composition of the present invention contains an acid diffusion controller (D) together with the copolymer resin (A), the radiation-sensitive acid generator (B) and the acid crosslinking agent (C). It is characterized by.
Further, the compounding amount of the radiation-sensitive acid generator (B) is 0.1 to 20 parts by weight based on 100 parts by weight of the copolymer resin (A).
Further, the radiation-sensitive acid generator (B) is characterized by containing at least one or more acid generators selected from the following formulas (2-1), (2-2) and (2-3). And

The formula (2-1), in the formula (2-2) and formula (2-3), X ^- is, R ³ -SO ₃ ^- represents, R ^3, even if it is partially or all fluorinated R ² represents a hydrogen atom or an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and R ⁴ represents a partially or fully fluorinated group. Represents an aliphatic hydrocarbon group or an aromatic hydrocarbon group, U represents a divalent organic group, and R ⁵ and R ⁶ independently represent a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic group; Represents a group hydrocarbon group, m represents an integer of 0 to 3, and n represents an integer of 0 to 2.
Further, the radiation-sensitive acid generator (B) is preferably represented by the formula (2-3).

上記式（４）において、Ｒ²³およびＲ²⁴は互いに独立に水素原子もしくはアルキル基、または、互いに結合して形成された脂環式炭化水素基もしくは芳香族炭化水素基を表し、Ｒ²⁵は水素原子、アルキル基、または、−Ｃ（Ｏ）ＯＲ²⁷基を表し、Ｒ²⁷はアルキル基を表し、Ｒ²⁶は水素原子、アルキル基、脂環式炭化水素基、または、芳香族炭化水素基を表す。 The negative radiation-sensitive resin composition of the present invention is characterized in that the compounding amount of the acid crosslinking agent (C) is 0.5 to 50 parts by weight based on 100 parts by weight of the copolymer resin (A).
The resin component is dissolved in a solvent, and the total solid content concentration is 3 to 50% by weight.
Here, the measurement of the total solid content is performed by drying about 1 g of the negative-type radiation-sensitive resin composition sample at 100 ° C. for 4 hours.
The solvent is 2-hexanone, 2-heptanone, 2-octanone, cyclopentanone, cyclohexanone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 3- Methyl ethoxypropionate, ethyl 3-ethoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol Monoethyl ether, n-butyl acetate , Methyl pyruvate, ethyl pyruvate, diethylene glycol monomethyl ether, characterized in that at least one solvent selected from the group consisting of diethylene glycol monoethyl ether and γ- butyrolactone.
Further, the acid diffusion controller (D) is characterized by being represented by the following formula (4).

In the above formula (4), R ²³ and R ²⁴ are each independently a hydrogen atom or an alkyl group, or represents an alicyclic hydrocarbon group or aromatic hydrocarbon group which is formed by bonding, R ²⁵ is hydrogen Represents an atom, an alkyl group, or a —C (O) OR ²⁷ group, R ²⁷ represents an alkyl group, and R ²⁶ represents a hydrogen atom, an alkyl group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group. Represent.

  The negative radiation-sensitive resin composition of the present invention contains a repeating unit (1-1) represented by the formula (1-1) and a repeating unit (1-2) represented by the formula (1-2). Containing a copolymer resin (A), a radiation-sensitive acid generator (B), and an acid crosslinking agent (C). A space pattern can be formed, and it is possible to suppress the occurrence of defects represented by undissolved residue at the bottom of the pattern and bridging at the top of the pattern, which are considered to be caused by insufficient solubility of the unirradiated part in the developing solution. it can. Further, it is possible to hold and control a rectangular pattern shape even in the fine region while suppressing pattern collapse in the fine region caused by swelling.

A conventional chemically amplified negative resist using an ArF light source imparts a dissolution rate of a non-irradiated portion by copolymerizing a repeating unit containing a carboxyl group, but in this case, the dissolution rate increases. Therefore, it is difficult to adjust the resist pattern, and the resolution of the resist pattern is low. Therefore, a negative-type radiation-sensitive resin composition suitable as a chemically amplified negative-type resist excellent in sensitivity, developability, dimensional fidelity, and the like has not yet been commercialized.
By using a copolymer containing a repeating unit (1-1) in which at least one of X ¹ and X ² contains a fluoroalkyl group and a repeating unit (1-2), the fluoro group of the repeating unit (1-1) It has been found that the dissolution rate of the unirradiated portion in the resist pattern can be easily adjusted by the action of the alkyl group. The present invention is based on such findings. The dissolution rate is measured by measuring the time required for the film thickness when developed under a predetermined developing condition to decrease from an initial value to reach a predetermined value, and [(initial film thickness−predetermined film thickness) / Time].

Each component constituting the negative radiation-sensitive resin composition will be described.
Copolymer resin (A):
In the repeating unit (1-1) constituting the copolymer resin (A), Y represents a divalent organic group. Examples of the organic group include a linear, branched, or alicyclic hydrocarbon group.
As the linear or branched hydrocarbon group, a hydrocarbon group having 1 to 12 carbon atoms is preferable, and specific examples thereof include divalent hydrocarbon groups derived from methane, ethane, propane, butane, isobutane, and the like. Can be
The alicyclic hydrocarbon group is preferably an alicyclic hydrocarbon group having 6 to 20 carbon atoms, and specific examples include cyclohexane, bicyclo [2.2.1] heptane, and 2-methylbicyclo [2.2. 1] heptane, adamantane, tricyclo [5.2.1.0 ^2,6 ] decane, tetracyclo [6.2.1.1 ^3,6 . [ ^2,7 ] dodecane.
Among the divalent organic groups represented by Y, propane, butane, isobutane, cyclohexane, 2-methylbicyclo [2.2.1] heptane, tetracyclo [6.2.1.1 ^3,6 . [0 ^2,7 ] Dodecane is preferably a divalent organic group.

In the repeating unit (1-1), the fluoroalkyl group is preferably a fluoroalkyl group having 1 to 4 carbon atoms, and specific examples include a monofluoromethyl group, a difluoromethyl group, and a trifluoromethyl group. Among these, a trifluoromethyl group and the like are preferable. Fluoroalkyl group is at least one of X ¹ and X ^2, preferably X ¹ and X ² are fluoroalkyl groups.

In the repeating unit (1-2), Z represents a divalent to tetravalent organic group. Examples of the organic group include a linear, branched, or alicyclic hydrocarbon group.
As the linear or branched hydrocarbon group, a linear or branched hydrocarbon group having 1 to 12 carbon atoms is preferable, and specific examples are derived from methane, ethane, propane, butane, isobutane, and the like. Examples thereof include a divalent to tetravalent hydrocarbon group.
The alicyclic hydrocarbon group is preferably an alicyclic hydrocarbon group having 6 to 20 carbon atoms, and specific examples thereof include cyclohexane, bicyclo [2.2.1] heptane, adamantane, and tricyclo [5.2.1]. 0.0 ^2,6 ] decane, tetracyclo [6.2.1.1 ^3,6 . [ ^2,7 ] dodecane, and a divalent to tetravalent alicyclic hydrocarbon group.
Among the divalent organic group represented by Z, ethane, propane, isopropane, butane, isobutane, cyclohexane, bicyclo [2.2.1] heptane, tetracyclo [6.2.1.1 ^{3, 6.} [ ^02,7 ] Dodecane is preferably a divalent to tetravalent organic group.

In the repeating unit (1-2), T represents a single bond or a divalent organic group having 1 to 3 carbon atoms, and specifically, a divalent group derived from a single bond, methane, ethane, propane, isopropane, or the like. Hydrocarbon group. Among these, a single bond, a methylene group, an ethylene group and the like are preferable.
In the formula (1-2), n represents an integer of 1 to 3, and 1 or 2 is preferable.

As the monomer giving the repeating unit (1-1) represented by the formula (1-1), (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy- 3-propyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-tri (Fluoro-2-trifluoromethyl-2-hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester, ( (Meth) acrylic acid 2-{[5- (1 ′, 1 ′, 1′-trifluoro-2′-trifluoromethyl-2′-hydroxy) propyl] bicyclo [2.2.1] heptyl} ester; Meta) Acri 3-{[8- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] tetracylate] tetracyclo [6.2.1.1 ^3,6 . ( ^2,7 ) dodecyl ester and the like.
In the present invention, “(meth) acrylic acid” indicates both “methacrylic acid” and “acrylic acid”.

Examples of the monomer giving the repeating unit (1-2) represented by the formula (1-2) include (meth) acrylic acid hydroxymethyl ester, (meth) acrylic acid 1-hydroxyethyl ester, and (meth) acrylic acid 2-hydroxyethyl ester, (meth) acrylic acid 1-hydroxypropyl ester, (meth) acrylic acid 2-hydroxypropyl ester, (meth) acrylic acid 3-hydroxypropyl ester, (meth) acrylic acid 3-hydroxyadamantane-1 -Yl ester, 3,5-dihydroxyadamantan-1-yl (meth) acrylate, 3,5,7-trihydroxyadamantan-1-yl (meth) acrylate, 5-hydroxybicyclo (meth) acrylate [2.2.1] Heptane-2-yl ester, (meth) acryl 5-hydroxymethylbicyclo [2.2.1] heptane-2-yl ester, (meth) acrylic acid 5-hydroxymethylbicyclo [2.2.1] heptane-2-methyl ester, (meth) acrylic acid 8- Hydroxytetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane-3-yl ester, 8-hydroxymethyltetracyclo (meth) acrylate [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane-3-yl ester, 8-hydroxytetracyclo (meth) acrylate [6.2.1.1 ^3,6 . ( ^2,7 ) dodecane-3-methyl ester and the like.

The copolymer resin (A) of the present invention may further contain other repeating units in addition to the repeating unit (1-1) and the repeating unit (1-2).
Examples of the monomer giving another repeating unit include (meth) acrylic acid, (meth) acrylic acid carboxymethyl ester, (meth) acrylic acid-2-carboxyethyl ester, and (meth) acrylic acid-3-carboxyadamantane -1-yl ester, (meth) acrylic acid-5-carboxybicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid cyanomethyl ester, (meth) acrylic acid-2-cyanoethyl ester, (Meth) acrylic acid-3-cyanoadamantan-1-yl ester, (meth) acrylic acid-5-cyanobicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid methyl ester, (meth) ) Acrylic acid ethyl ester, (meth) acrylic acid adamantane-1-yl ester, (meth) a Bicyclo [2.2.1] hepta-2-yl acrylate, 7,7-dimethylbicyclo [2.2.1] hepta-1-yl acrylate, (meth) acrylic acid tricyclo [meth] acrylate 5.2.1.0 ^2,6 ] dec-8-yl ester, (meth) acrylic acid-7-oxo-6-oxa-bicyclo [3.2.1] oct-4-yl ester, (meth) Acrylic acid-2-methoxycarbonyl-7-oxo-6-oxa-bicyclo [3.2.1] oct-4-yl ester, (meth) acrylic acid-2-oxotetrahydropyran-4-yl ester, (meth ) Acrylic acid-4-methyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2-oxo Tetrahydrofuran-3-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-3,3-dimethyl-5-oxotetrahydrofuran-2-ylmethyl ester, N, N -Dimethyl (meth) acrylamide, crotonamide, maleamide, fumaramide, mesaconamide, citraconamide, itaconamide and the like.

The copolymer resin (A) of the present invention is preferably composed of the repeating unit (1-1) and the repeating unit (1-2), and the copolymer resin (A) contains at least one kind of each repeating unit. be able to.
The repeating unit (1-2) is preferably a combination of a repeating unit containing an alicyclic hydrocarbon group as Z and a repeating unit containing no alicyclic hydrocarbon group. The copolymer of the present invention comprises a repeating unit (1-1), a repeating unit containing an alicyclic hydrocarbon group and a repeating unit (1-2) containing no alicyclic hydrocarbon group. Is preferable because a rectangular resist pattern can be formed without generating bridging defects.
The mixing ratio of each repeating unit is such that the repeating unit (1-1) is 40 to 80 mol%, preferably 50 to 80 mol%, and the repeating unit (1-2) is 5 to 60 mol%, based on all repeating units. , Preferably 10 to 50 mol%. When the content of the repeating unit (1-1) is less than 40 mol%, the solubility in the developing solution tends to deteriorate. Is too high in solubility and tends to degrade in resolution and swell.
When the content of the repeating unit (1-2) is less than 5 mol%, the degree of crosslinking in the irradiated part tends to be insufficient, and the resolution tends to deteriorate, and the content of the repeating unit (1-2) is 60 mol%. %, The developability tends to decrease, and the irradiated portion tends to swell.

The copolymer resin (A) is obtained by, for example, using a mixture of monomers corresponding to each repeating unit with a radical polymerization initiator such as a hydroperoxide, a dialkyl peroxide, a diacyl peroxide, or an azo compound; If necessary, it can be produced by polymerizing in a suitable solvent in the presence of a chain transfer agent.
Examples of the solvent used for the polymerization include cycloalkanes such as cyclohexane and cycloheptane; saturated carboxylic esters such as ethyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate and propylene glycol monomethyl ether acetate. Alkyl lactones such as γ-butyrolactone; ethers such as tetrahydrofuran, dimethoxyethane, and diethoxyethane; alkyl ketones such as 2-butanone, 2-heptanone, and methyl isobutyl ketone; cycloalkyl ketones such as cyclohexanone; Examples thereof include alcohols such as 2-propanol and propylene glycol monomethyl ether.
These solvents can be used alone or in combination of two or more.
The reaction temperature in the polymerization is usually 40 to 120 ° C, preferably 50 to 100 ° C, and the reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

Naturally, the copolymer resin (A) has a small amount of impurities such as halogens and metals, and preferably has a residual monomer or oligomer component of a predetermined value or less, for example, 0.1% by weight by HPLC, As a result, not only can the sensitivity, resolution, process stability, pattern shape, and the like of the resist be further improved, but also a resist free from foreign substances in the liquid and changes over time in sensitivity and the like can be provided.
Examples of the method for purifying the copolymer resin (A) include the following methods. As a method for removing impurities such as metals, a method of adsorbing metals in a resin solution using a zeta potential filter or removing the metals in a chelated state by washing the resin solution with an acidic aqueous solution such as oxalic acid or sulfonic acid And the like. Further, as a method of removing the residual monomer or oligomer component to a specified value or less, a liquid-liquid extraction method of removing the residual monomer or oligomer component by washing with water or combining an appropriate solvent, a method of removing a specific molecular weight or less A purification method in a solution state such as ultrafiltration for extracting and removing only a resin, a reprecipitation method and a filtration method for removing residual monomers and the like by coagulating the resin in the poor solvent by dropping the resin solution into the poor solvent. There is a purification method in a solid state such as washing with another resin slurry poor solvent. Also, these methods can be combined. The poor solvent used in the reprecipitation method depends on the physical properties and the like of the resin to be purified, and cannot be unequivocally exemplified. The poor solvent is appropriately selected.

In the present invention, the weight average molecular weight (hereinafter, referred to as “Mw”) of the copolymer resin (A) in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably from 1,000 to 50,000, and particularly preferably from 4,000. 000 to 40,000 is preferred. In this case, if the Mw of the copolymer resin (A) is less than 1,000, a sufficient dissolution inhibiting ability does not appear in the irradiated portion and it does not tend to function as a negative resist. The radiation-irradiated portion has insufficient solubility in an alkali developing solution and tends to not function as a negative resist.
Further, the degree of dispersion defined by the ratio (Mw / Mn) between the Mw of the copolymer resin (A) and the number average molecular weight in terms of polystyrene by gel permeation chromatography (GPC) (hereinafter referred to as “Mn”) is as follows: In the present invention, it is preferably from 1.0 to 5.00, particularly preferably from 1.25 to 2.25. When the degree of dispersion is 1.25 or less, a defect of the negative resist pattern tends to occur, and when it exceeds 5.00, the resolution of the negative resist tends to decrease.
In the present invention, the copolymer resin (A) preferably has "Mw" of 1,000 to 50,000 and a dispersity of 1.25 to 5.00.
In the present invention, the copolymer resin (A) can be used alone or in combination of two or more.

式（２−１）、式（２−２）および式（２−３）において、Ｘ⁻はＲ³−ＳＯ₃ ⁻を表し、Ｒ³は、部分的もしくは全てフッ素化されていてもよい炭化水素基を表す。この炭化水素基は炭素数１〜８の直鎖状もしくは分岐状の脂肪族炭化水素基、または炭素数６〜１２の脂環式炭化水素基もしくは芳香族炭化水素基を表す。ｎは０〜２の整数を表す。
Ｒ³−ＳＯ₃ ⁻の具体例としては、ノナフルオロ−ｎ−ブタンスルホン酸、パーフルオロ−ｎ−オクタンスルホン酸、２−（ビシクロ［２．２．１］ヘプト−２−イル）−１，１，２，２−テトラフルオロエタンスルホン酸、カンファースルホン酸等の陰イオンが挙げられる。 Radiation-sensitive acid generator (B):
The radiation-sensitive acid generator (B) that can be used in combination with the copolymer resin (A) is a component that generates an acid upon irradiation with radiation.
The acid generator suitable in the present invention preferably contains at least one or more acid generators selected from the following formulas (2-1), (2-2) and (2-3).
The radiation-sensitive acid generator (B1) having a dissolution time of less than 7 minutes and the radiation-sensitive acid generator (B1) having a dissolution time of 7 minutes or more are obtained, depending on the elution time measured by HPLC under specific conditions. It can be separated into the acid generator (B2), and the distinction is also accompanied by the following specific examples.

In the formula (2-1), (2-2) and formula (2-3), X ^- is R ³ -SO ₃ ^- represents, R ³ is partially or may be any fluorinated hydrocarbon Represents a hydrogen group. This hydrocarbon group represents a linear or branched aliphatic hydrocarbon group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group or an aromatic hydrocarbon group having 6 to 12 carbon atoms. n represents the integer of 0-2.
Specific examples of R ³ —SO ₃ ^— include nonafluoro-n-butanesulfonic acid, perfluoro-n-octanesulfonic acid, and 2- (bicyclo [2.2.1] hept-2-yl) -1,1. And anions such as 2,2,2-tetrafluoroethanesulfonic acid and camphorsulfonic acid.

In the formula (2-1), R ² is a hydrogen atom, a linear or branched aliphatic hydrocarbon group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group having 6 to 12 carbon atoms or an aromatic group. Represents a group hydrocarbon group. Specific examples of R ² include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a cyclopentyl group, a cyclohexyl group, a bicyclo [2.2.1] heptyl group, an adamantyl group, and a tricycloalkyl group. [5.2.1.0 ^2,6 ] decanyl group, tetracyclo [6.2.1.1 ^3,6 . [0 ^2,7 ] dodecanyl group.

Specific examples of the radiation-sensitive acid generator represented by the formula (2-1) include triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, and triphenylsulfonium 2- ( Bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate and triphenylsulfonium camphorsulfonate, which correspond to the radiation-sensitive acid generator (B1) I do.
Also, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2- (bicyclo [2.2.1] hept-2 -Yl) -1,1,2,2-tetrafluoroethanesulfonate and 4-cyclohexylphenyldiphenylsulfonium camphorsulfonate, which correspond to the radiation-sensitive acid generator (B2).
Also, 4-t-butylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-t-butylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-t-butylphenyldiphenylsulfonium 2- (bicyclo [2.2 .1] hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate and 4-t-butylphenyldiphenylsulfonium camphorsulfonate, which correspond to the radiation-sensitive acid generator (B1) I do.
Also, tri (4-t-butylphenyl) sulfonium nonafluoro-n-butanesulfonate, tri (4-t-butylphenyl) sulfonium perfluoro-n-octanesulfonate, tri (4-t-butylphenyl) sulfonium 2- (Bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate and tri (4-t-butylphenyl) sulfonium camphorsulfonate, which are radiation-sensitive This corresponds to the acid generator (B2).

In the formula (2-2), R ⁴ represents a hydrocarbon group which may be partially or completely fluorinated. This hydrocarbon group represents a linear or branched aliphatic hydrocarbon group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group or an aromatic hydrocarbon group having 6 to 12 carbon atoms. U represents an oxygen atom, a sulfur atom, a sulfoxide group, a sulfonyl group, an oxysulfonyl group, a sulfonyloxy group, or the like. n represents the integer of 0-2.
Specific examples of R ⁴ include, as those not fluorinated, a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a cyclopentyl group, a cyclohexyl group, a bicyclo [2.2.1. ] Heptyl group, adamantyl group, tricyclo [5.2.1.0 ^2,6 ] decanyl group, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecanyl group, camphor group and the like. Examples of fluorinated groups include a trifluoromethyl group, a nonafluoro-n-butyl group, a perfluoro-n-octyl group, and a 2- (bicyclo [2 2.1] hept-2-yl) -1,1,2,2-tetrafluoroethyl group and the like.

Specific examples of the radiation-sensitive acid generator represented by the formula (2-2) include 4-n-butylsulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate and 4-n-butylsulfonylphenyldiphenylsulfonium perfluoro -N-octanesulfonate, 4-n-butylsulfonylphenyldiphenylsulfonium 2- (bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, 4-n- And butylsulfonylphenyldiphenylsulfonium camphorsulfonate, which corresponds to the radiation-sensitive acid generator (B1).
Also, 4-cyclohexylsulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylsulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylsulfonylphenyldiphenylsulfonium 2- (bicyclo [2.2.1] Hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate and 4-cyclohexylsulfonylphenyldiphenylsulfonium camphorsulfonate, which correspond to the radiation-sensitive acid generator (B1).
Also, 4-nonafluoro-n-butylsulfonyloxyphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-nonafluoro-n-butylsulfonyloxyphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-nonafluoro-n-butylsulfonyl Oxyphenyldiphenylsulfonium 2- (bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, 4-nonafluoro-n-butylsulfonyloxyphenyldiphenylsulfonium camphorsulfonate These correspond to the radiation-sensitive acid generator (B2).
Also, 4-camphorsulfonyloxyphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-camphorsulfonyloxyphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-camphorsulfonyloxyphenyldiphenylsulfonium 2- (bicyclo [2.2 .1] hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate and 4-camphorsulfonyloxyphenyldiphenylsulfonium camphorsulfonate, which correspond to the radiation-sensitive acid generator (B2) I do.
Also, 4- (bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethylsulfonyloxyphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4- (bicyclo [2 2.2.1] Hept-2-yl) -1,1,2,2-tetrafluoroethylsulfonyloxyphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4- (bicyclo [2.2.1] hept-2 -Yl) -1,1,2,2-tetrafluoroethylsulfonyloxyphenyldiphenylsulfonium 2- (bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethanesulfonate , 4- (Bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoroethylsulfonyl Hydroxyphenyl camphorsulfonate and the like, which corresponds to the radiation-sensitive acid generator (B2).

In the formula (2-3), R ⁵ and R ⁶ independently represent a hydrogen atom or a hydrocarbon group. This hydrocarbon group represents a linear or branched aliphatic hydrocarbon group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group or an aromatic hydrocarbon group having 6 to 12 carbon atoms. m represents an integer of 0 to 3, and n represents an integer of 0 to 2.
Specific examples of R ⁵ and R ⁶ include a hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, cyclopentyl group, cyclohexyl group, bicyclo [2.2.1] heptyl group, adamantyl Group, tricyclo [5.2.1.0 ^2,6 ] decanyl group, tetracyclo [6.2.1.1 ^3,6 . [0 ^2,7 ] dodecanyl group.

Specific examples of the radiation-sensitive acid generator represented by the formula (2-3) include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (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 and 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium camphorsulfonate. This corresponds to the radioactive acid generator (B1).
Also, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n -Octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoro Ethane sulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium camphorsulfonate, which correspond to the radiation-sensitive acid generator (B1).

Acid generators that can be used together with the acid generators of the formulas (2-1), (2-2) and (2-3) that are suitable for the present invention are referred to as "other radiation-sensitive acid generators". And specific examples thereof include diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, and diphenyliodonium 2- (bicyclo [2.2.1] hept-2-yl). -1,1,2,2-tetrafluoroethanesulfonate and diphenyliodonium camphorsulfonate, which correspond to the radiation-sensitive acid generator (B1).
Also, 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 bis (4-t-butylphenyl) iodonium camphorsulfonate, which are radiation-sensitive This corresponds to the acid generator (B2).
Also, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- [2- (bicyclo [2.2.1] hept-2-yl)- 1,1,2,2-tetrafluoroethanesulfonyloxy] succinimide and N- (camphorsulfonyloxy) succinimide, which correspond to the radiation-sensitive acid generator (B1).
Also, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2 2.1] hept-5-ene-2,3-dicarboximide, N-[(-(bicyclo [2.2.1] hept-2-yl) -1,1,2,2-tetrafluoro Ethanesulfonyloxy] bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3 -Dicarboximides, which correspond to the radiation-sensitive acid generator (B1).

In the present invention, the radiation-sensitive acid generator (2-1), the radiation-sensitive acid generator (2-2), the radiation-sensitive acid generator (2-3) and other radiation-sensitive acid generators are referred to as "generic name". Are referred to as "radiation-sensitive acid generators (B)" can be used alone or in combination of two or more.
The amount of the radiation-sensitive acid generator (B) to be used is preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the copolymer resin (A), from the viewpoint of securing the sensitivity and resolution as a resist. Is 0.1 to 15 parts by weight. In this case, if the amount of the radiation-sensitive acid generator (B) used is less than 0.1 part by weight, sensitivity and developability tend to decrease, while if it exceeds 20 parts by weight, transparency to radiation decreases. Therefore, a phenomenon (T-top phenomenon) of insolubilizing only the resist surface tends to occur, so that it becomes difficult to obtain a resist pattern.

上記式（３−１）において、Ｒ⁷〜Ｒ¹⁰は互いに独立に炭素数１〜４の直鎖状もしくは分岐状のアルキル基を表す。具体的には、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基等が挙げられる。
式（３−１）で表されるＮ−(アルコキシメチル)グリコールウリル化合物の具体例としては、Ｎ,Ｎ,Ｎ,Ｎ−テトラ(メトキシメチル)グリコールウリル、Ｎ,Ｎ,Ｎ,Ｎ−テトラ(エトキシメチル)グリコールウリル、Ｎ,Ｎ,Ｎ,Ｎ−テトラ(ｎ−プロポキシメチル)グリコールウリル、Ｎ,Ｎ,Ｎ,Ｎ−テトラ(ｉ−プロポキシメチル)グリコールウリル、Ｎ,Ｎ,Ｎ,Ｎ−テトラ(ｎ−ブトキシメチル)グリコールウリル、Ｎ,Ｎ,Ｎ,Ｎ−テトラ(ｔ−ブトキシメチル)グリコールウリル等が挙げられる。 Acid crosslinking agent (C):
The acid cross-linking agent (C) in the present invention cross-links the copolymer resin (A), which is an alkali-soluble resin, in the presence of an acid generated from the radiation-sensitive acid generator (B) upon irradiation, for example, to form an alkali developer. The type is not particularly limited as long as it can suppress the solubility of the compound in the present invention, but in the present invention, it is particularly represented by an N- (alkoxymethyl) glycoluril compound represented by the following formula (3-1). It preferably contains an acid crosslinking agent (C).

In the above formula (3-1), R ^{7 to} R ¹⁰ independently represent a linear or branched alkyl group having 1 to 4 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and an isobutyl group.
Specific examples of the N- (alkoxymethyl) glycoluril compound represented by the formula (3-1) include N, N, N, N-tetra (methoxymethyl) glycoluril and N, N, N, N-tetra (Ethoxymethyl) glycoluril, N, N, N, N-tetra (n-propoxymethyl) glycoluril, N, N, N, N-tetra (i-propoxymethyl) glycoluril, N, N, N, N -Tetra (n-butoxymethyl) glycoluril, N, N, N, N-tetra (t-butoxymethyl) glycoluril and the like.

上記式（３−２）、（３−３）および（３−４）において、Ｒ¹¹〜Ｒ²²は互いに独立に炭素数１〜４の直鎖状、分岐状のアルキル基を表す。具体的には、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基等が挙げられる。
上記式（３−２）で表されるＮ−(アルコキシメチル)ウレア化合物の具体例としては、Ｎ,Ｎ−ジ(メトキシメチル)ウレア、Ｎ,Ｎ−ジ(エトキシメチル)ウレア、Ｎ,Ｎ−ジ(ｎ−プロポキシメチル)ウレア、Ｎ,Ｎ−ジ(ｉ−プロポキシメチル)ウレア、Ｎ,Ｎ−ジ(ｎ−ブトキシメチル)ウレア、Ｎ,Ｎ−ジ(ｔ−ブトキシメチル)ウレア等が挙げられ。
また、上記式（３−３）で表されるＮ−(アルコキシメチル)メラミン化合物の具体例としては、Ｎ,Ｎ,Ｎ,Ｎ,Ｎ,Ｎ−ヘキサ（メトキシメチル）メラミン、 Ｎ,Ｎ,Ｎ,Ｎ,Ｎ,Ｎ−ヘキサ（エトキシメチル）メラミン、 Ｎ,Ｎ,Ｎ,Ｎ,Ｎ,Ｎ−ヘキサ（ｎ−プロポキシメチル）メラミン、 Ｎ,Ｎ,Ｎ,Ｎ,Ｎ,Ｎ−ヘキサ（ｉ−プロポキシメチル）メラミン、 Ｎ,Ｎ,Ｎ,Ｎ,Ｎ,Ｎ−ヘキサ（ｎ−ブトキシメチル）メラミン、 Ｎ,Ｎ,Ｎ,Ｎ,Ｎ,Ｎ−ヘキサ（ｔ−ブトキシメチル）メラミン等が挙げられる。
また、上記式（３−４）で表されるＮ−(アルコキシメチル)エチレンウレア化合物の具体例としては、Ｎ,Ｎ−ジ(メトキシメチル)−４,５−ジ（メトキシメチル）エチレンウレア、Ｎ,Ｎ−ジ(エトキシメチル)−４,５−ジ（エトキシメチル）エチレンウレア、Ｎ,Ｎ−ジ(ｎ−プロポキシメチル)−４,５−ジ（ｎ−プロポキシメチル）エチレンウレア、Ｎ,Ｎ−ジ(ｉ−プロポキシメチル)−４,５−ジ（ｉ−プロポキシメチルメチル）エチレンウレア、Ｎ,Ｎ−ジ(ｎ−ブトキシメチル)−４,５−ジ（ｎ−ブトキシメチル）エチレンウレア、Ｎ,Ｎ−ジ(ｔ−ブトキシメチル)−４,５−ジ（ｔ−ブトキシメチルメチル）エチレンウレア等が挙げられる。 In the present invention, the negative radiation-sensitive resin composition may contain an acid crosslinking agent other than the acid crosslinking agent (3-1) (hereinafter referred to as “other acid crosslinking agent”). Is an N- (alkoxymethyl) urea compound represented by the following formula (3-2), an N- (alkoxymethyl) melamine compound represented by the following formula (3-3), and a compound represented by the following formula (3-4) And N- (alkoxymethyl) amino compounds such as the represented N- (alkoxymethyl) ethyleneurea compound.

In the above formulas (3-2), (3-3) and (3-4), R ^{11 to} R ²² each independently represent a linear or branched alkyl group having 1 to 4 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and an isobutyl group.
Specific examples of the N- (alkoxymethyl) urea compound represented by the above formula (3-2) include N, N-di (methoxymethyl) urea, N, N-di (ethoxymethyl) urea, N, N -Di (n-propoxymethyl) urea, N, N-di (i-propoxymethyl) urea, N, N-di (n-butoxymethyl) urea, N, N-di (t-butoxymethyl) urea and the like No.
Specific examples of the N- (alkoxymethyl) melamine compound represented by the above formula (3-3) include N, N, N, N, N, N-hexa (methoxymethyl) melamine, N, N, N, N, N, N-hexa (ethoxymethyl) melamine, N, N, N, N, N, N-hexa (n-propoxymethyl) melamine, N, N, N, N, N, N-hexa ( i-propoxymethyl) melamine, N, N, N, N, N, N-hexa (n-butoxymethyl) melamine, N, N, N, N, N, N, N-hexa (t-butoxymethyl) melamine and the like No.
Specific examples of the N- (alkoxymethyl) ethylene urea compound represented by the above formula (3-4) include N, N-di (methoxymethyl) -4,5-di (methoxymethyl) ethylene urea N, N-di (ethoxymethyl) -4,5-di (ethoxymethyl) ethyleneurea, N, N-di (n-propoxymethyl) -4,5-di (n-propoxymethyl) ethyleneurea, N, N-di (i-propoxymethyl) -4,5-di (i-propoxymethylmethyl) ethyleneurea, N, N-di (n-butoxymethyl) -4,5-di (n-butoxymethyl) ethyleneurea , N, N-di (t-butoxymethyl) -4,5-di (t-butoxymethylmethyl) ethyleneurea and the like.

In the present invention, the acid cross-linking agent (C) can be used alone or as a mixture of two or more, and particularly preferably contains at least one or more acid cross-linking agents (3-1). It is preferable to appropriately contain an acid cross-linking agent.
In the present invention, the content of the acid crosslinking agent (C) is preferably 0.5 to 50 parts by weight, more preferably 1 to 50 parts by weight, based on 100 parts by weight of the copolymer resin (A) which is an alkali-soluble resin. It is 30 parts by weight, more preferably 2 to 20 parts by weight. When the compounding amount of the acid crosslinking agent (C) is less than 0.5 part by weight, the insolubilizing effect of lowering the solubility of the copolymer resin (A) in an alkali developing solution is insufficient, and the pattern easily swells, and There is a tendency for meandering and the like to be observed, and for the sensitivity to be significantly reduced. On the other hand, when the amount exceeds 50 parts by weight, there is a tendency that the heat resistance and the transparency of the resist are reduced, and that only the resist surface is insolubilized.

上記式（４）において、Ｒ²³およびＲ²⁴は、互いに独立に水素原子または炭素数１〜６の直鎖状、分岐状もしくは環状のアルキル基、または、Ｒ²³およびＲ²⁴が互いに結合して形成された炭素数４〜１２の脂環式炭化水素基もしくは芳香族炭化水素基を表す。
Ｒ²⁵は、水素原子または炭素数１〜６の直鎖状、分岐状もしくは環状のアルキル基、または、−Ｃ（Ｏ）ＯＲ²⁷基を表す。
Ｒ²⁶は、水素原子または炭素数１〜６の直鎖状、分岐状もしくは環状のアルキル基、または、炭素数６〜１２の脂環式の脂環式炭化水素基もしくは芳香族炭化水素基を表す。
Ｒ²⁷は、水素原子または炭素数１〜６の直鎖状、分岐状もしくは環状のアルキル基を表す。
Ｒ²³およびＲ²⁴における、炭素数１〜６の直鎖状、分岐状あるいは環状のアルキル基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、シクロペンチル基、シクロヘキシル基が挙げられ、互いに結合して形成された炭素数４〜１２の脂環式炭化水素基もしくは芳香族炭化水素基としては、シクロペンチル基、シクロヘキシル基、シクロヘプチル基、フェニル基、ナフチル基等が挙げられ、これらは置換基を有していてもよい。
Ｒ²⁵における、水素原子または炭素数１〜６の直鎖状、分岐状もしくは環状のアルキル基としては、水素原子、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、シクロペンチル基、シクロヘキシル基が挙げられ、または、−Ｃ（Ｏ）ＯＲ²⁷基が挙げられる。
Ｒ²⁶における、炭素数１〜６の直鎖状、分岐状もしくは環状のアルキル基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、シクロペンチル基、シクロヘキシル基が挙げられ、炭素数６〜１２の脂環式の脂環式炭化水素基あるいは芳香族炭化水素基としては、シクロヘキシル基、シクロヘプチル基、フェニル基、ナフチル基が挙げられ、かつ、これらは置換基を有していてもよい。
Ｒ²⁷における、水素原子または炭素数１〜６の直鎖状、分岐状もしくは環状のアルキル基としては、水素原子、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、シクロペンチル基、シクロヘキシル基が挙げられる。 Acid diffusion controller (D)
The negative-working radiation-sensitive resin composition of the present invention controls the diffusion phenomenon of an acid generated from the radiation-sensitive acid generator (B) in the resist film by irradiation with radiation, thereby preventing undesired chemicals in the non-radiation-irradiated region. It is preferable to add an acid diffusion controlling agent having an action of suppressing the reaction.
The acid diffusion controller (D) is not particularly limited as long as it has a strong affinity for an acid, but in the present invention, it is particularly preferable to contain at least one or more acid diffusion controllers represented by the following formula (4). .

In the above formula (4), R ²³ and R ²⁴ are each independently a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or R ²³ and R ²⁴ are bonded to each other. Represents an alicyclic hydrocarbon group or an aromatic hydrocarbon group having 4 to 12 carbon atoms formed.
R ²⁵ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a —C (O) OR ²⁷ group.
R ²⁶ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or an alicyclic alicyclic hydrocarbon group or an aromatic hydrocarbon group having 6 to 12 carbon atoms. Represent.
R ²⁷ represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms.
Examples of the linear, branched or cyclic alkyl group having 1 to 6 carbon atoms for R ²³ and R ²⁴ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a cyclopentyl group and a cyclohexyl group. Examples of the alicyclic hydrocarbon group or aromatic hydrocarbon group having 4 to 12 carbon atoms formed by bonding to each other include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a phenyl group, and a naphthyl group. And these may have a substituent.
Examples of a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms for R ²⁵ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and a cyclopentyl group. , A cyclohexyl group, or a -C (O) OR ²⁷ group.
Examples of the linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms for R ²⁶ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the alicyclic alicyclic hydrocarbon group or aromatic hydrocarbon group having 6 to 12 carbon atoms include a cyclohexyl group, a cycloheptyl group, a phenyl group and a naphthyl group, and these have a substituent. It may be.
Examples of a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms for R ²⁷ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and a cyclopentyl group. And a cyclohexyl group.

Specific examples of the acid diffusion controller represented by the above formula (4) include imidazole, 4-methylimidazole, 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, -Phenylbenzimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole, 1-benzylimidazole, 1-methyl-2 -Phenylbenzimidazole, 1-benzyl-2-phenylbenzimidazole and the like.
By blending such an acid diffusion controller, the storage stability of the resulting negative-type radiation-sensitive resin composition is further improved, and the resolution as a resist is further improved, and from the irradiation to the development processing. It is possible to suppress a change in the line width of the resist pattern due to a change in the withdrawal time (PED), and not only to obtain a composition having excellent process stability, but also to suppress a variation in solubility from the top to the bottom of the pattern. In particular, bridging at the upper part of the pattern and unmelted residue at the lower part of the pattern can be suppressed.

Further, the negative-type radiation-sensitive resin composition of the present invention comprises an acid diffusion controller having a skeleton other than the acid diffusion controller represented by the above formula (4) (hereinafter referred to as “other acid diffusion controller”). ) Can be contained.
Examples of other acid diffusion controllers include “tertiary amine compounds”, “amide group-containing compounds”, “quaternary ammonium hydroxide compounds”, and “nitrogen-containing heterocyclic compounds”.
Examples of the “tertiary amine compound” include, for example, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n Tri (cyclo) alkylamines such as octylamine, cyclohexyldimethylamine, dicyclohexylmethylamine and tricyclohexylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4 Aromatic amines such as -methylaniline, 4-nitroaniline, 2,6-dimethylaniline and 2,6-diisopropylaniline; alkanolamines such as triethanolamine and N, N-di (hydroxyethyl) aniline; N , N, N ', N'-tetramethylethylene Amine, N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, bis (2- Dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether and the like.
Examples of the “amide group-containing compound” include, for example, Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxy Carbonyl-N-methyl-1-adamantylamine, N, N-di-tert-butoxycarbonyl-1-adamantylamine, N, N-di-tert-butoxycarbonyl-N-methyl-1-adamantylamine, Nt -Butoxycarbonyl-4,4'-diaminodiphenylmethane, N, N'-di-t-butoxycarbonylhexamethylenediamine, N, N, N'N'-tetra-t-butoxycarbonylhexamethylenediamine, 1- (t -Butoxycarbonyl) -2-pyrrolidinemethanol, t-butyl (tetrahydro-2- Oxa-3-furanyl) carbamate, N, N′-di-tert-butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl group-containing amino compounds such as Nt-butoxycarbonyl-2-phenylbenzimidazole and the like.
Examples of the “quaternary ammonium hydroxide compound” include tetra-n-propylammonium hydroxide, tetra-n-butylammonium hydroxide and the like.
As the “nitrogen-containing heterocyclic compound”, for example, pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4 Pyridines such as phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline and acridine; piperazines such as piperazine and 1- (2-hydroxyethyl) piperazine, and pyrazines , Pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] Octane and the like.
Of these other acid diffusion controllers, tertiary amine compounds and Nt-butoxycarbonyl group-containing amino compounds are preferred.

In the present invention, the acid diffusion controller (D) can be used alone or as a mixture of two or more, and particularly preferably contains at least one or more acid diffusion controllers represented by the formula (4). In addition, it is preferable to appropriately contain other acid diffusion controlling agents.
The compounding amount of the acid diffusion controller (D) is usually 15 parts by weight or less, preferably 10 parts by weight or less, more preferably 5 parts by weight or less based on 100 parts by weight of the copolymer resin (A). In this case, if the amount of the acid diffusion controller (D) exceeds 15 parts by weight, the sensitivity as a resist tends to be significantly reduced. If the amount of the acid diffusion controller is less than 0.001 part by weight, the pattern shape and dimensional fidelity as a resist may be reduced depending on the process conditions.

In the negative radiation-sensitive resin composition of the present invention, various additives such as a dissolution controlling agent, a dissolution accelerator, a surfactant, and a sensitizer can be blended.
Dissolution control agent:
When the solubility of the copolymer resin (A), which is an alkali-soluble resin, in an alkali developer is too high, the solubility control agent controls the solubility of the copolymer resin and appropriately reduces the dissolution rate of the resin during alkali development. It is a component that has an effect. As such a dissolution controlling agent, a dissolution controlling agent that does not chemically change in the steps of baking, radiation irradiation, development and the like of the resist film is preferable.
As the dissolution controlling agent, saturated hydrocarbons, particularly hydrocarbons having an alicyclic skeleton are preferable, and compounds that do not show alkali solubility alone are preferable. These dissolution controlling agents can be used alone or in combination of two or more.
Dissolution promoter:
When the solubility of the copolymer resin (A), which is an alkali-soluble resin, in an alkali developer is too low, the dissolution accelerator enhances the solubility of the copolymer resin (A) to appropriately increase the dissolution rate of the resin during alkali development. It is a component which has. As such a dissolution accelerator, one that does not chemically change in steps such as baking, irradiation of radiation, and development of a resist film is preferable.
As the dissolution accelerator, saturated hydrocarbons, particularly hydrocarbons having an alicyclic skeleton are preferable, and compounds which are alkali-soluble alone are preferable. These dissolution controlling agents can be used alone or in combination of two or more.
The compounding amount of the above-mentioned dissolution controlling agent or dissolution promoter is usually 50 parts by weight or less, preferably 30 parts by weight or less based on 100 parts by weight of the copolymer resin (A). In this case, when the amount of the dissolution controlling agent or the dissolution promoter exceeds 50 parts by weight, the heat resistance of the resist tends to decrease.

Surfactant:
The negative-working radiation-sensitive resin composition of the present invention may contain a surfactant having an effect of improving coatability, developability and the like.
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, and polyethylene glycol. In addition to nonionic surfactants such as distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and Polyflow No. No. 75, the same No. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, and EF352 (manufactured by Tochem Products), Megafax F171 and F173 (manufactured by Dainippon Ink and Chemicals, Inc.), Florard FC430, FC431 (manufactured by Sumitomo 3M Limited), Asahigard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( (Made by Asahi Glass Co., Ltd.). These surfactants can be used alone or in combination of two or more.
The amount of the surfactant is usually 2 parts by weight or less based on 100 parts by weight of the copolymer resin (A).

Sensitizer:
The negative-type radiation-sensitive resin composition of the present invention may contain a sensitizer having an effect of improving sensitivity and the like.
Preferred sensitizers include, for example, carbazoles, benzophenones, rose bengals, anthracenes, phenols and the like. These sensitizers can be used alone or in combination of two or more.
The amount of the sensitizer is preferably 50 parts by weight or less based on 100 parts by weight of the copolymer resin (A).
Furthermore, examples of the additives other than the above include an antihalation agent, an adhesion aid, a storage stabilizer, and an antifoaming agent.

Upon use, the negative-type radiation-sensitive resin composition of the present invention is dissolved in a solvent so that the total solid content concentration is usually 3 to 50% by weight, preferably 5 to 25% by weight. It is prepared as a composition solution by filtering with a filter having a pore size of about 200 nm.
Examples of the solvent used for preparing this composition solution include 2-hexanone, 2-heptanone, 2-octanone, cyclopentanone, cyclohexanone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and 2-hydroxy. Methyl propionate, ethyl 2-hydroxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene Glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene Glycol monoethyl ether acetate n- butyl, methyl pyruvate, ethyl pyruvate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, .gamma.-butyrolactone.
These solvents can be used alone or as a mixture of two or more. Among the above examples, 2-heptanone, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl 2-hydroxypropionate, 3-ethoxy Ethyl propionate, propylene glycol monomethyl ether, γ-butyrolactone, and the like are preferable, and in the present invention, it is particularly preferable that at least propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and the like are contained.

The negative radiation-sensitive resin composition of the present invention is particularly useful as a chemically amplified negative resist.
In the chemically amplified negative resist, an electrophilic site is formed from the acid crosslinking agent (C) by the action of the acid generated from the radiation-sensitive acid generator (B) upon irradiation, and the electrophilic site is formed by the copolymer resin (A). ), An electrophilic attack on a polar group, for example, a hydroxyl group, causes a crosslinking reaction. As a result, the solubility of the irradiated portion of the resist in the alkali developing solution is reduced, and the unirradiated portion is dissolved and removed by the alkali developing solution, so that a negative resist pattern is obtained.
When forming a resist pattern from the negative-type radiation-sensitive resin composition of the present invention, the composition solution, by a suitable coating means such as spin coating, casting coating, roll coating, spray coating, for example, silicon wafer After applying a heat treatment (hereinafter referred to as “PB”) in some cases, the resist film is irradiated with radiation so as to form a predetermined resist pattern. I do. Radiation used at that time is, for example, far ultraviolet rays such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), EUV (extreme ultraviolet light, wavelength 13 nm, etc.). A charged particle beam such as an electron beam and an X-ray such as synchrotron radiation can be appropriately selected and used, and of these, far ultraviolet rays and an electron beam are preferable. The irradiation conditions such as the irradiation dose are appropriately selected according to the composition of the negative-type radiation-sensitive resin composition, the type of each additive, and the like.
In the present invention, in order to stably form a high-precision fine pattern, it is preferable to perform a heat treatment (hereinafter, referred to as “PEB”) after irradiation with radiation. Due to this PEB, a crosslinking reaction in the radiation irradiation part proceeds smoothly. The PEB heating conditions vary depending on the composition of the negative radiation-sensitive resin composition, but are usually 30 to 200 ° C, preferably 50 to 170 ° C.

In the present invention, in order to maximize the potential of the negative-type radiation-sensitive resin composition, for example, as disclosed in Japanese Patent Publication No. 6-12452, an organic or inorganic A system antireflection film can be formed in advance, and in order to prevent the influence of basic impurities and the like contained in the environmental atmosphere, a resist such as disclosed in Japanese Patent Application Laid-Open No. 188598/1993 is used. A protective film can be provided on the coating, or these techniques can be used in combination.
Next, a predetermined resist pattern is formed by developing the resist film irradiated with radiation. As a developer used for development, for example, an alkaline aqueous solution in which tetramethylammonium hydroxide is dissolved is preferable. The concentration of the alkaline aqueous solution is usually 1 to 10% by weight, preferably 1 to 5% by weight. In addition, an appropriate amount of a surfactant or the like can be added to a developer composed of an alkaline aqueous solution. After development with a developing solution composed of an alkaline aqueous solution, the film is generally washed with water and dried.

Hereinafter, examples of the present invention will be described more specifically. Here, parts are by weight unless otherwise specified.
Each measurement and evaluation in Examples and Comparative Examples was performed in the following manner.
(1) Mw and Mw / Mn:
Tosoh Corporation GPC column (G2000H _XL 2 present, one G3000H _XL, G4000H _XL one) using, Flow rate: 1.0 ml / minute, eluting solvent tetrahydrofuran, in the analysis conditions of column temperature 40 ° C., monodisperse polystyrene Was measured by gel permeation chromatography (GPC) using as standard.
(2) Sensitivity:
Using a substrate having an ARC29A (manufactured by Nissan Chemical Industries) film with a thickness of 78 nm formed on the surface of a silicon wafer, each composition solution was applied on the substrate by spin coating, and then heated on a hot plate at a temperature of 105 ° C. at 90 ° C. Using a Nikon ArF excimer laser exposure apparatus (optical conditions: NA = 0.55, 2/3 Annular), a portion coated with Cr was coated on the resist film having a thickness of 265 nm formed by performing PB under the conditions of seconds. Irradiation was performed through a phase shift mask (PSM mask) that transmits 6% of the laser beam and inverts the phase by 180 degrees. Thereafter, PEB is performed at a temperature of 105 ° C. for 90 seconds, and then developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 25 ° C. for 60 seconds, washed with water, and dried to obtain a negative mold. Was formed. At this time, the radiation dose for forming a line-and-space pattern (1L1S) having a line width of 140 nm in a one-to-one line width was defined as an optimum radiation dose, and the optimum radiation dose was defined as sensitivity.
(3) Resolution:
The minimum line-and-space pattern dimension resolved at the optimal radiation dose was defined as the resolution and defined at three levels of 140 nm, 130 nm, and 120 nm.
(4) HPLC measurement conditions for acid generator:
An ODS column manufactured by GL Sciences Co., Ltd. was used, and an eluent obtained by adding 0.1% by weight of phosphoric acid to water in acetonitrile / water = 60/40 (weight ratio) was used. It was measured at milliliter / min. For detection, the maximum was measured by the area of the absorption at 220 nm. The radiation-sensitive acid generator having an elution time of less than 7 minutes is referred to as (B1), and the radiation-sensitive acid generator for 7 minutes or more is referred to as (B2).
(5) Radiation transmittance:
A resist formed by applying a resin solution in which resin is dissolved in propylene glycol monomethyl ether acetate (PGMEA) by spin coating on quartz glass, and performing PB on a hot plate at 105 ° C. for 90 seconds. The radiation transmittance at a film thickness of 265 nm was calculated from the absorbance at a wavelength of 193 nm measured for the coating.

(6) Residual film ratio:
The thickness of the resist film formed by spin coating on the surface of a silicon wafer and performing PB on a hot plate at 105 ° C. for 90 seconds is A, and the resist film is Residual film ratio = (B / A), where the resist film was developed with a .38% by weight aqueous solution of tetramethylammonium hydroxide at 25 ° C. for 60 seconds, washed with water, and dried to obtain a measured film thickness B of the resist film. It was calculated by the formula of X100.
(7) Residual residue at the bottom of the pattern
The bottom of the pattern may exhibit an extreme skirting shape due to the balance between the solubility of the resin and the solubility after crosslinking. As a result of visual judgment by cross-sectional SEM observation, “○” indicates that footing is not observed, “△” indicates that footing is observed but resolution is performed to the substrate, and “△” indicates footing is observed and reaches the substrate. Those that have not been resolved are indicated by “x”.
(8) Bridging at the top of the pattern:
Bridging may be observed at the upper part of the pattern depending on the balance between the solubility of the resin and the solubility after crosslinking. When judged visually by cross-sectional SEM observation, "○" indicates that bridging was not observed, and "△" indicates that bridging remains were observed but did not reach the connection between patterns. Those in which the connection between the patterns can be observed are indicated by "x".

１００ミリリットルの三口フラスコにメタクリル酸（１，１，１−トリフルオロ−２−トリフルオロメチル−２−ヒドロキシ−４−ペンチル）エステル（Ｓ１−１）５．４２ｇ（７０モル％）、メタクリル酸（３−ヒドロキシアダマンタン−１−イル）エステル（Ｓ１−２）１．２４ｇ（２０モル％）、メタクリル酸（１−ヒドロキシエチル）エステル（Ｓ１−３）０．３４ｇ（１０モル％）と２−プロパノール１７．８６ｇとを入れ、撹拌溶解の後、内温８０℃で３０分間窒素置換した。そこへ２，２−アゾビス（イソブチロニトリル）０．０９ｇを投入し、窒素雰囲気下で還流条件下で、１６時間重合した。重合終了後、重合溶液は水冷することにより３０℃以下に冷却し、２２００ｇのｎ−ヘキサンへ投入し、析出した白色粉末をろ別する。ろ別された白色粉末を３度５５ｇのｎ−ヘキサンにてスラリー状で洗浄した後、ろ別し、６０℃にて１７時間乾燥し、白色粉末の共重合樹脂を得た（５．６７ｇ、収率８１％）。この共重合樹脂はＭｗが３９，４００、Ｍｗ／Ｍｎは３．１７であった。¹³Ｃ−ＮＭＲ測定により、（Ｓ１−１）、（Ｓ１−２）、（Ｓ１−３）の各繰り返し単位の含有率が６９．０：２０．１：１０．９（モル％）の共重合体であった。この共重合樹脂を樹脂（Ａ−１）とする。この樹脂（Ａ−１）の放射線透過率は、８２．５％であった。 Synthesis Example 1

In a 100-ml three-necked flask, 5.42 g (70 mol%) of methacrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester (S1-1), methacrylic acid ( 1.24 g (20 mol%) of 3-hydroxyadamantan-1-yl) ester (S1-2), 0.34 g (10 mol%) of methacrylic acid (1-hydroxyethyl) ester (S1-3) and 2-propanol 17.86 g, and after stirring and dissolving, the atmosphere was replaced with nitrogen at an internal temperature of 80 ° C for 30 minutes. Thereto was added 0.09 g of 2,2-azobis (isobutyronitrile), and the mixture was polymerized under a refluxing condition under a nitrogen atmosphere for 16 hours. After completion of the polymerization, the polymerization solution is cooled to 30 ° C. or lower by water cooling, poured into 2200 g of n-hexane, and the precipitated white powder is separated by filtration. The filtered white powder was washed with 55 g of n-hexane three times in a slurry state, then filtered and dried at 60 ° C. for 17 hours to obtain a white powder copolymer resin (5.67 g, Yield 81%). This copolymer resin had Mw of 39,400 and Mw / Mn of 3.17. ^{By 13} C-NMR measurement, the weight of each of the repeating units (S1-1), (S1-2), and (S1-3) was 69.0: 20.1: 10.9 (mol%). It was united. This copolymer resin is referred to as resin (A-1). The radiation transmittance of this resin (A-1) was 82.5%.

Synthesis Example 2
Methacrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester (S1-1) 11.60 g (70 mol%), methacrylic acid (3-hydroxyadamantane-1) 2.66 g (20 mol%) of (-yl) ester (S1-2) and 0.73 g (10 mol%) of methacrylic acid (1-hydroxyethyl) ester (S1-3) were dissolved in 30 g of 2-butanone. A monomer solution charged with 0.19 g of 2,2-azobis (isobutyronitrile) is prepared, and a 100 ml three-necked flask charged with 15 g of 2-butanone is purged with nitrogen for 30 minutes. After the nitrogen purge, the reactor was heated to an internal temperature of 80 ° C. while stirring, and the above-prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours, with the start of the dropwise addition as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled to 30 ° C. or lower by water cooling, poured into 600 g of n-hexane, and the precipitated white powder is separated by filtration. The filtered white powder was washed twice with 60 g of n-hexane in a slurry state, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder copolymer resin (12.12 g, Yield 80.8%). This copolymer resin had Mw of 14,600 and Mw / Mn of 2.05. ^{By 13} C-NMR measurement, the weight of each of the repeating units (S1-1), (S1-2), and (S1-3) was 67.2: 21.8: 11.0 (mol%). It was united. This copolymer resin is referred to as a resin (A-2). The radiation transmittance of this resin (A-2) was 81.6%.

Synthesis Example 3
Methacrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester (S1-1) 11.60 g (70 mol%), methacrylic acid (3-hydroxyadamantane-1) 2.66 g (20 mol%) of (-yl) ester (S1-2) and 0.73 g (10 mol%) of methacrylic acid (1-hydroxyethyl) ester (S1-3) were dissolved in 30 g of 2-butanone. A monomer solution charged with 0.37 g of 2,2-azobis (isobutyronitrile) is prepared, and a 100 ml three-necked flask charged with 15 g of 2-butanone is purged with nitrogen for 30 minutes. After the nitrogen purge, the reactor was heated to an internal temperature of 80 ° C. while stirring, and the above-prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours, with the start of the dropwise addition as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled to 30 ° C. or lower by water cooling, poured into 600 g of n-hexane, and the precipitated white powder is separated by filtration. The filtered white powder was washed twice in a slurry form with 60 g of n-hexane, then filtered and dried at 60 ° C. for 17 hours to obtain a white powder copolymer resin (12.24 g, Yield 81.6%). This copolymer resin had Mw of 10,500 and Mw / Mn of 2.00. ^{According to 13} C-NMR measurement, the content of each repeating unit of (S1-1), (S1-2), and (S1-3) was 68.3: 21.0: 10.7 (mol%). It was united. This copolymer resin is referred to as a resin (A-3). The radiation transmittance of this resin (A-3) was 80.6%.

Synthesis Example 4
15.47 g (70 mol%) of methacrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester (S1-1), methacrylic acid (3-hydroxyadamantane-1) -Yl) ester (S1-2) 3.55 g (20 mol%) and methacrylic acid (1-hydroxyethyl) ester (S1-3) 0.98 g (10 mol%) were dissolved in 2-butanone 40 g. A monomer solution charged with 0.99 g of 2,2-azobis (isobutyronitrile) is prepared, and a 100 ml three-necked flask charged with 20 g of 2-butanone is purged with nitrogen for 30 minutes. After the nitrogen purge, the reactor was heated to an internal temperature of 80 ° C. while stirring, and the above-prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours, with the start of the dropwise addition as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled to 30 ° C. or lower by cooling with water, poured into 800 g of n-hexane, and the precipitated white powder is filtered. The filtered white powder was washed twice with 80 g of n-hexane in a slurry form, filtered, and dried at 60 ° C. for 17 hours to obtain a resin as a white powder (14.92 g, yield). 74.6%). This copolymer resin had Mw of 6,600 and Mw / Mn of 1.88. ^{According to 13} C-NMR measurement, the content of each of the repeating units (S1-1), (S1-2) and (S1-3) was 66.6: 23.1: 10.4 (mol%). It was united. This copolymer resin is referred to as a resin (A-4). The radiation transmittance of this resin (A-4) was 76.4%.

Synthesis Example 5
15.47 g (70 mol%) of methacrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester (S1-1), methacrylic acid (3-hydroxyadamantane-1) -Yl) ester (S1-2) 3.55 g (20 mol%) and methacrylic acid (1-hydroxyethyl) ester (S1-3) 0.98 g (10 mol%) were dissolved in 2-butanone 40 g. A monomer solution charged with 1.48 g of 2,2-azobis (isobutyronitrile) is prepared, and a 100 ml three-necked flask charged with 20 g of 2-butanone is purged with nitrogen for 30 minutes. After the nitrogen purge, the reactor was heated to an internal temperature of 80 ° C. while stirring, and the above-prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours, with the start of the dropwise addition as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled to 30 ° C. or lower by cooling with water, poured into 800 g of n-hexane, and the precipitated white powder is filtered. The filtered white powder was washed twice with 80 g of n-hexane in a slurry form, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder resin (15.92 g, yield). 79.6%). This copolymer resin had Mw of 4,300 and Mw / Mn of 1.60. ^{According to 13} C-NMR measurement, the content of each repeating unit of (S1-1), (S1-2), and (S1-3) was 67.5: 22.2: 10.3 (mol%). It was united. This copolymer resin is referred to as a resin (A-5). The radiation transmittance of this resin (A-5) was 76.2%.

Synthesis Example 6
13.56 g (60 mol%) of methacrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester (S1-1), methacrylic acid (3-hydroxyadamantane-1) -Yl) ester (S1-2) (5.44 g, 30 mol%) and methacrylic acid (1-hydroxyethyl) ester (S1-3), 1.00 g (10 mol%), were dissolved in 2-butanone (40 g). A monomer solution containing 1.43 g of 2,2-azobis (isobutyronitrile) and 0.31 g of n-dodecanethiol was prepared, and a 100 ml three-necked flask charged with 20 g of 2-butanone was charged with nitrogen for 30 minutes. Purge. After the nitrogen purge, the reactor was heated to an internal temperature of 80 ° C. while stirring, and the above-prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours, with the start of the dropwise addition as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled to 30 ° C. or lower by cooling with water, poured into 800 g of n-hexane, and the precipitated white powder is filtered. The filtered white powder was washed twice with 80 g of n-hexane in a slurry form, filtered, and dried at 60 ° C. for 17 hours to obtain a white powder resin (15.92 g, yield). 79.6%). This copolymer resin had Mw of 5,600 and Mw / Mn of 1.69. ^{According to 13} C-NMR measurement, the weight of each of the repeating units (S1-1), (S1-2), and (S1-3) was 67.0: 22.4: 10.6 (mol%). It was united. This copolymer resin is referred to as a resin (A-6). The resin (A-6) had a radiation transmittance of 75.6%.

Examples 1 to 17
Various evaluations were performed on each composition solution composed of the components shown in Table 1. Table 2 shows the evaluation results. Components other than the polymers (A-1) to (A-6) in Table 1 are as follows.
Radiation-sensitive acid generator (B)
B-1: 4-t-butylphenyl / diphenylsulfonium / nonafluoro-n-butanesulfonate (HPLC elution time: 7.21 minutes)
B-2: Triphenylsulfonium nonafluoro-n-butanesulfonate (HPLC elution time: 4.71 minutes)
B-3: 4-cyclohexylsulfonylphenyl / diphenylsulfonium / nonafluoro-n-butanesulfonate (HPLC elution time: 6.60 minutes)
B-4: 4-Camphorsulfonyloxyphenyl / diphenylsulfonium nonafluoro-n-butanesulfonate (HPLC elution time: 8.30 minutes)
B-5: 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate (HPLC elution time: 7.32 minutes)
Acid crosslinking agent (C)
C-1: N, N, N, N-tetra (methoxymethyl) glycolurilic acid diffusion controller (D)
D-1: Tetra (n-butyl) ammonium hydroxide D-2: 2-Phenylbenzimidazole solvent (E)
E-1: Propylene glycol monomethyl ether acetate

  The negative-working radiation-sensitive resin composition of the present invention is expected to be further miniaturized in the future as a chemically amplified negative-working resist that is sensitive to actinic radiation, in particular, far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm). It can be used very suitably in the manufacture of semiconductor devices to be manufactured.

Claims (10)

A copolymer resin (A) containing a repeating unit (1-1) represented by the following formula (1-1) and a repeating unit (1-2) represented by the following formula (1-2); A negative-type radiation-sensitive resin composition, comprising: an acid generator (B); and an acid crosslinking agent (C).

(In the above formulas (1-1) and (1-2), R ¹ represents a hydrogen atom or a methyl group. In the formula (1-1), X ¹ and X ² each independently represent a hydrogen atom or a fluoro group. X represents an alkyl group, and at least one of X ¹ and X ² represents a fluoroalkyl group; Y represents a divalent organic group; Z represents a divalent to tetravalent organic group; Represents a divalent organic group of 1-3, and n represents an integer of 1-3.) 2. The negative-type radiation-sensitive resin according to claim 1, wherein the copolymer resin (A) has a weight average molecular weight in terms of polystyrene of 1,000 to 50,000 as measured by gel permeation chromatography (GPC). 3. Composition. The negative mold according to claim 1, further comprising an acid diffusion controller (D) together with the copolymer resin (A), the radiation-sensitive acid generator (B), and the acid crosslinking agent (C). Radiation-sensitive resin composition. The negative radiation sensitive composition according to claim 1, wherein the amount of the radiation sensitive acid generator (B) is 0.1 to 20 parts by weight based on 100 parts by weight of the copolymer resin (A). Resin composition. The radiation-sensitive acid generator (B) contains at least one or more acid generators selected from the following formulas (2-1), (2-2) and (2-3). The negative-type radiation-sensitive resin composition according to claim 1.

In (the above formula (2-1), (2-2) and formula (2-3), X ^- is, R ³ -SO ₃ ^- represents, R ³ is partially or have been all fluorinated R ² represents a hydrogen atom or a hydrocarbon group, R ⁴ represents a hydrocarbon group which may be partially or completely fluorinated, and U represents a divalent organic group. R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group, m represents an integer of 0 to 3, and n represents an integer of 0 to 2.) The negative radiation-sensitive resin composition according to claim 5, wherein the radiation-sensitive acid generator (B) has the formula (2-3). 2. The negative radiation-sensitive resin composition according to claim 1, wherein the amount of the acid crosslinking agent (C) is 0.5 to 50 parts by weight based on 100 parts by weight of the copolymer resin (A). object. The negative radiation-sensitive resin composition according to claim 1, wherein the resin component is dissolved in a solvent, and the total solid content concentration is 3 to 50% by weight. The negative radiation-sensitive resin composition according to claim 8, wherein the solvent is at least one solvent selected from the following group.
Solvent group: 2-hexanone, 2-heptanone, 2-octanone, cyclopentanone, cyclohexanone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 3- Methyl ethoxypropionate, ethyl 3-ethoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol Monoethyl ether, n-butyl acetate Methyl pyruvate, ethyl pyruvate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, .gamma.-butyrolactone. The negative-type radiation-sensitive resin composition according to claim 2, wherein the acid diffusion controller (D) is represented by the following formula (4).

In (the above formula (4), R ²³ and R ²⁴ are each independently a hydrogen atom or an alkyl group, or represents an alicyclic hydrocarbon group or aromatic hydrocarbon group which is formed by bonding, R ²⁵ is A hydrogen atom, an alkyl group, or a —C (O) OR ²⁷ group; R ²⁷ represents an alkyl group; R ²⁶ represents a hydrogen atom, an alkyl group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group; Represents.)