JPH0784360A - Radiation sensitive resin composition - Google Patents

Abstract

PURPOSE:To provide a chemical amplification type radiation sensitive resin composition excellent in sensitivity, resolution, and the like, specially excellent in coating property to a large-bored base by a spin-coating method. CONSTITUTION:Resist for forming a pattern by generating acid by the irradiation of radiation and changing the solubility of a radiation irradiated part to a developer by chemical change due to the catalytic action of the acid is dissolved in a solvent to form a radiation sensitive resin composition. The solvent in this case contains a monoketone compound (ketone group solvent) of 5-10 carbon. As the ketone group solvent, it is desirable to use methylamyl ketone, methylisoamyl ketone, methylhexyl ketone, or the like. The ketone group solvent can be suitably used in the same way singularly or in the mixed state of several kinds of ketone compounds different in structure regarding the sort of an alkyl group and the sort of an isomer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a radiation-sensitive resin composition. More specifically, especially ultraviolet rays, far ultraviolet rays, X
The present invention relates to a radiation-sensitive resin composition which is a resist suitable for ultrafine processing using radiation such as rays or charged particle rays.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuits, miniaturization of the processing size in lithography is progressing in order to obtain a higher degree of integration of integrated circuits. A technique capable of stably performing the following fine processing is required. Therefore, it is necessary to accurately form a pattern of 0.5 μm or less in the resist used. Therefore, a lithography technique using shorter wavelength radiation has been studied. Examples of such radiation include ultraviolet rays typified by i rays (365 nm), far ultraviolet rays typified by KrF excimer lasers (248 nm), X rays typified by synchrotron radiation, and charged particle rays typified by electron beams. Etc. can be mentioned. In recent years, various resists corresponding to these radiations have been proposed. Of these, a resist that causes a reaction that changes the solubility in a developing solution due to the catalytic action of an acid generated by irradiation with radiation is usually attracting attention. Type resist ".

When a resist is actually used in the manufacturing process of an integrated circuit, a resist solution is usually prepared by dissolving a radiation-sensitive component constituting a "resist" such as a radiation-sensitive component and a film-forming resin component in a solvent. Then, spin coating or roll coating is applied to the substrate to be processed to form a resist film. Therefore, performances such as coating property and storage stability of the resist solution are indispensable performances for stably performing advanced fine processing. Further, the resist film forms a pattern suitable for fine processing by irradiating radiation, but the shape of the pattern at this time has an important influence on the accuracy of the fine processing, and a rectangular shape is preferable. There is.

In a resist using a novolac resin and a naphthoquinonediazide type photosensitizer used in conventional lithography, it is known to use ethylene glycol monoethyl ether acetate or the like as a solvent when preparing a resist solution. There is. However, regarding the "chemically amplified resist", there is a problem in storage stability when ethylene glycol monoethyl ether acetate is used as a solvent when preparing a resist solution. That is, when ethylene glycol monoethyl ether acetate is used as a solvent, there is a problem in that the sensitivity of the resist film and the shape of the formed pattern vary with the lapse of time after the preparation of the resist solution. Further, with the recent increase in the degree of integration of integrated circuits, in order to improve the yield and efficiency at the time of manufacturing integrated circuits, the diameter of the substrate (silicon wafer) has been increased, for example, from 4 inches to 6 inches and 8 inches. However, it can be said that the chemical amplification type resist using ethylene glycol monoethyl ether acetate, which is generally used as a solvent for the conventional chemical amplification type resist, does not necessarily have sufficient coatability by spin coating on a substrate having a large diameter. There wasn't.

[0005]

An object of the present invention is to provide a novel radiation-sensitive resin composition, which has sensitivity,
It is an object of the present invention to provide a radiation-sensitive resin composition which is excellent in resolution and the like and is particularly suitable as a chemically amplified radiation-sensitive resin composition having excellent coatability by spin coating on a substrate having a large diameter. Another object of the present invention is to provide a radiation-sensitive resin composition capable of stably performing fine processing, having excellent storage stability, and forming a resist film which gives a good pattern shape. Still another object of the present invention is to have good resist sensitivity even after a long time after preparation of a resist solution, to form an excellent pattern shape with good reproducibility, and to have excellent radiation stability with excellent storage stability. It is to provide a resin composition. Further objects and advantages of the present invention will be apparent from the following description.

[0006]

According to the present invention, the above objects and advantages of the present invention are as follows.
In a radiation-sensitive resin composition obtained by dissolving a resist that forms a pattern by changing the solubility of a radiation-irradiated portion in a developer by a chemical change due to the catalytic action of the acid, the solvent has 5 carbon atoms. It is achieved by a radiation-sensitive resin composition, which is a solvent containing a monoketone compound of 10 to 10 (hereinafter referred to as "ketone solvent"). Typical compositions of the radiation-sensitive resin composition of the present invention include, for example, the following resist compositions.

(A) (a) An alkali-insoluble or sparingly alkali-soluble resin protected with an acid-decomposable group, which becomes alkali-soluble when the acid-decomposable group is decomposed (hereinafter,
It is referred to as "acid-decomposable group-containing resin". ), (B) a compound that generates an acid upon irradiation with radiation (hereinafter referred to as “radiation-sensitive acid generator”), and (c) a positive-type radiation-sensitive resin composition containing a ketone solvent (hereinafter, "Resist composition (a)"),

(B) (a) Alkali-soluble resin,
(B) a radiation-sensitive acid generator, (c) having a property of controlling the alkali solubility of the alkali-soluble resin of (a),
A compound which is decomposed in the presence of an acid to reduce or eliminate the alkali solubility control effect of the alkali-soluble resin of (a), or has the action of promoting the alkali solubility of the alkali-soluble resin of (a). (Hereinafter, referred to as “dissolution control agent”), and (d) a positive-type radiation-sensitive resin composition containing a ketone solvent (hereinafter, referred to as “resist composition (b)”),

(C) (a) Alkali-soluble resin,
(B) a radiation-sensitive acid generator, (c) a compound capable of cross-linking the alkali-soluble resin (a) in the presence of an acid (hereinafter referred to as "cross-linking agent"), and (d) a ketone solvent Negative radiation-sensitive resin composition (hereinafter, referred to as "resist composition (C)").

Hereinafter, these resist compositions will be described. Radiation-sensitive acid generator As the radiation-sensitive acid generator used in the present invention, that is, a compound that generates an acid in response to radiation, for example, an onium salt compound, a halogen-containing compound, a sulfone compound,
And sulfonate compounds. More specifically, the following compounds can be mentioned.

A) Onium salts Iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts and the like can be mentioned. Preferably, diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyl iodonium dodecylbenzene sulfonate, triphenyl sulfonium triflate, triphenyl sulfonium hexafluoroantimonate, triphenyl sulfonium naphthalene sulfonate, (hydroxyphenyl) benzylmethyl sulfonium toluene sulfonate, etc. is there.

A) Halogen-containing compound: Haloalkyl group-containing heterocyclic compounds, haloalkyl group-containing hydrocarbon compounds and the like can be mentioned. Preferably, phenyl-bis (trichloromethyl) -s-triazine, methoxyphenyl-bis (trichloromethyl)-
(Trichloromethyl) -s- such as s-triazine and naphthyl-bis- (trichloromethyl) -s-triazine
It is a triazine derivative or 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane.

C) Sulfone compounds β-ketosulfones, β-sulfonylsulfones and their α-diazo compounds can be mentioned. Preferred are phenacylphenyl sulfone, mesitylphenacyl sulfone, bis (phenylsulfonyl) methane, bis (phenylsulfonyl) diazomethane and the like.

D) Sulfonate compounds Alkyl sulfonates, haloalkyl sulfonates, aryl sulfonates, imino sulfonates and the like can be mentioned. Preferably, benzoin tosylate, tristriflate of pyrogallol, nitrobenzyl-9,10-diethoxyanthracene-2
-Sulfonates and the like.

These radiation-sensitive acid generators can be used alone or in admixture of two or more.

Acid-decomposable group-containing resin The acid-decomposable group-containing resin in the resist composition (a) is
For example, one or more substituents (hereinafter referred to as "acid-decomposable group") capable of decomposing an acidic functional group such as a phenolic hydroxyl group or a carboxyl group in an alkali-soluble resin described below in the presence of an acid to develop alkali solubility. Alkali-insoluble resin or alkali-insoluble resin obtained by substituting the. The term "alkali-insoluble" or "alkali-poorly-soluble" as used herein means that the resist composition under the alkaline developing conditions adopted when forming a resist pattern from a resist film formed using the resist composition (a). When the film formed by using only the acid-decomposable group-containing resin instead of (a) is developed, the initial film thickness of the film is 50
% Means the property that remains after development.

The acid-decomposable group is a phenolic hydroxyl group,
A group in which an acidic functional group such as a carboxyl group is substituted with at least one acid-decomposable group capable of decomposing in the presence of an acid, and the group decomposes in the presence of an acid to form a functional group exhibiting alkali solubility. It is not particularly limited as long as it is, for example, substituted methyl group, 1-substituted ethyl group, 1-branched alkyl group, silyl group, germyl group, alkoxycarbonyl group,
Examples thereof include an acyl group and a cyclic acid-decomposable group.

Examples of the substituted methyl group include methoxymethyl group, methylthiomethyl group, ethoxymethyl group,
Ethylthiomethyl group, methoxyethoxymethyl group, benzyloxymethyl group, benzylthiomethyl group, phenacyl group, bromophenacyl group, methoxyphenacyl group,
(Methylthio) phenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, ethoxybenzyl group, ethylthiobenzyl group, piperonyl group Etc. can be mentioned.

The 1-substituted ethyl group is, for example, 1
-Methoxyethyl group, 1-methylthioethyl group, 1,1
-Dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1-diethoxyethyl group, 1-
Phenoxyethyl group, 1-phenylthioethyl group, 1,
1-diphenoxyethyl group, 1-benzyloxyethyl group, 1-benzylthioethyl group, 1-cyclopropylethyl group, 1-phenylethyl group, 1,1-diphenylethyl group, α-methylphenacyl group, etc. Can be mentioned.

Examples of the 1-branched alkyl group include isopropyl group, sec-butyl group, t-butyl group,
1,1-dimethylpropyl group, 1-methylbutyl group,
Examples thereof include a 1,1-dimethylbutyl group.

Examples of the silyl group include a trimethylsilyl group, an ethyldimethylsilyl group, a diethylmethylsilyl group, a triethylsilyl group, a dimethylisopropylsilyl group, a methyldiisopropylsilyl group, a triisopropylsilyl group, a t-butyldimethylsilyl group, and a diethylsilyl group. -T-
Butylmethylsilyl group, tri-t-butylsilyl group, dimethylphenylsilyl group, methyldiphenylsilyl group,
Examples thereof include a triphenylsilyl group.

Examples of the germyl group include trimethylgermyl group, ethyldimethylgermyl group, diethylmethylgermyl group, triethylgermyl group, dimethylisopropylgermyl group, methyldiisopropylgermyl group, triisopropylgermyl group, t-butyldimethylgermyl group, di-t-butylmethylgermyl group, tri-
t-butylgermyl group, dimethylphenylgermyl group,
Examples thereof include a methyldiphenylgermyl group and a triphenylgermyl group.

Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an isopropoxycarbonyl group, a t-butoxycarbonyl group and a t-pentyloxycarbonyl group.

Examples of the acyl group include acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, lauriloyl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group and malonyl group. Group, succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacyl group, acryloyl group, propioloyl group, methacryloyl group,
Crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, camphoroyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl Group, thenoyl group, nicotinoyl group, isonicotinoyl group, toluenesulfonyl group, mesyl group and the like.

Examples of the cyclic acid-decomposable group include cyclopropyl group, cyclopentyl group, cyclohexyl group,
Cyclohexenyl group, oxocyclohexenyl group, 4-
Methoxycyclohexyl group, tetrahydropyranyl group,
Tetrahydrofuranyl group, tetrahydrothiopyranyl group, tetrahydrothiofuranyl group, 3-bromotetrahydropyranyl group, 4-methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl group, S, S
-Dioxide group, 2-1,3-dioxolanyl group, 2-
Examples thereof include a 1,3-dithiolanyl group, a benzo-2-1,3-dioxolanyl group, a benzo2-1,3-dithiolanyl group, and the like.

Of these acid-decomposable groups, t-butyl group, benzyl group, t-butoxycarbonyl group, tetrahydropyranyl group, tetrahydrofuranyl group, tetrahydrothiopyranyl group, tetrahydrothiofuranyl group and the like are preferable.

The introduction rate of the acid-decomposable group in the acid-decomposable group-containing resin (the ratio of the number of acid-decomposable groups to the total number of acidic functional groups and acid-decomposable groups in the acid-decomposable group-containing resin) is , Preferably 15 to 100%, more preferably 20 to 10
0%, particularly preferably 20 to 80%.

The polystyrene-equivalent weight average molecular weight (hereinafter referred to as "Mw") of the acid-decomposable group-containing resin measured by gel permeation chromatography is preferably 1,000 to 150,000, and more preferably 3. 1,000 to 100,000.

The acid-decomposable group-containing resin is a resin having one or more acid-decomposable groups, for example, by introducing one or more acid-decomposable groups into one or more preliminarily prepared alkali-soluble resins. It can be produced by polymerization or copolymerization of a monomer or polycondensation or copolycondensation of a polycondensation component having one or more acid-decomposable groups.

The acid-decomposable group-containing resin used in the resist composition (a) has the property of controlling the alkali solubility of the alkali-soluble resin, and is decomposed in the presence of an acid to give the alkali-soluble resin. It has an effect of reducing or eliminating the alkali solubility control effect or an effect of promoting the alkali solubility of the alkali-soluble resin, and is in the category of the dissolution control agent used in the resist composition (b). Is.

These acid-decomposable group-containing resins can be used alone or in admixture of two or more.

The ratio of the radiation-sensitive acid generator to the acid-decomposable group-containing resin in the resist composition (a) is preferably such that the radiation-sensitive acid generator is 100 parts by weight of the acid-decomposable group-containing resin. The amount is 0.05 to 20 parts by weight, more preferably 0.1 to 15 parts by weight, and particularly preferably 0.5 to 10 parts by weight. If the amount of the radiation-sensitive acid generator is less than 0.05 parts by weight, it may be difficult to effectively cause a chemical change due to the catalytic action of the acid generated by irradiation of radiation, and more than 20 parts by weight. If so, there is a possibility that coating unevenness may occur when the resist composition (a) is applied, or scum may occur during development.

Alkali-Soluble Resin The alkali-soluble resin used in the resist composition (b) has a functional group having an affinity with an alkali developing solution, for example, an acidic functional group such as phenolic hydroxyl group and carboxyl group, There is no particular limitation as long as it is soluble in the liquid.

As such an alkali-soluble resin,
For example, hydroxystyrene, hydroxy-α-methylstyrene, vinylbenzoic acid, carboxymethylstyrene,
Cleavage of the polymerizable double bond of at least one monomer having an acidic functional group such as carboxymethoxystyrene, (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid, mesaconic acid and cinnamic acid. Examples thereof include a vinyl resin having a repeating unit and a condensation resin having a repeating repeating unit having an acidic functional group represented by novolak resin.

When the alkali-soluble resin is the vinyl-based resin, the resin may be composed only of repeating units in which the polymerizable double bond of the monomer having the acidic functional group is cleaved, As long as the above resin is soluble in an alkali developing solution, it may further have other repeating units, if necessary.

Examples of such other repeating units include styrene, α-methylstyrene, vinyltoluene, maleic anhydride, (meth) acrylonitrile, crotonnitrile, malein nitrile, fumaronitrile, mesacone nitrile, citracon nitrile and itacone nitrile. ,
(Meth) acrylamide, crotonamide, maleamide, fumaramide, mesacone amide, citracone amide, itaconamide, vinylaniline, vinylpyridine, vinyl-ε-caprolactam, vinylpyrrolidone,
An example is a unit in which a polymerizable double bond portion of a monomer having a polymerizable double bond such as vinylimidazole is cleaved.

Polymerization or copolymerization for producing the alkali-soluble resin composed of the vinyl resin is carried out by radical polymerization initiator, anionic polymerization catalyst, coordination anionic polymerization catalyst, depending on the kind of the monomer and the reaction medium. A polymerization initiator such as a cationic polymerization catalyst or a polymerization catalyst is appropriately selected, and bulk polymerization, solution polymerization, precipitation polymerization, emulsion polymerization, suspension polymerization, bulk polymerization
It can be carried out in an appropriate polymerization mode such as suspension polymerization.

When the alkali-soluble resin is the condensation resin, the resin may be composed of, for example, only a novolac resin unit, but as long as the produced resin is soluble in the alkali developing solution, It is possible to further have other condensation units. Such a condensation-type resin contains one or more phenols and one or more aldehydes, optionally together with a polycondensation component capable of forming another condensation-type repeating unit, in an aqueous medium in the presence of an acidic catalyst. Alternatively, it can be produced by a polycondensation reaction or a copolycondensation reaction in a mixed medium of water and a hydrophilic solvent.

In this case, examples of the phenols include o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol,
2,5-xylenol, 3,4-xylenol, 3,5
-Xylenol, 2,3,5-trimethylphenol,
Examples of the aldehydes include formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, and 3,4,5-trimethylphenol.
Examples thereof include phenylacetaldehyde.

The content of the repeating unit having an acidic functional group in the alkali-soluble resin cannot be unconditionally defined depending on the kind of other repeating units contained as necessary,
Usually 15 to 100 mol%, more preferably 20 to 1
It is 00 mol%.

The Mw of the alkali-soluble resin varies depending on the desired characteristics of the resist composition (b) or (c), but is preferably 1,000 to 150,000, more preferably 3,000 to 100,000. Is.

When the alkali-soluble resin has a repeating unit containing a carbon-carbon unsaturated bond, it can be used as a hydrogenated product. The hydrogenation rate in this case is usually the carbon-carbon unsaturated bond contained in the repeating unit,
It is 70% or less, preferably 50% or less, more preferably 40% or less. When the hydrogenation rate exceeds 70%, the developing property of the alkali-soluble resin with an alkali developing solution tends to deteriorate.

In the resist compositions (B) and (C), the alkali-soluble resin can be used alone or in combination of two or more kinds.

Dissolution Control Agent Next, the dissolution control agent used in the resist composition (b) has a property of controlling the alkali solubility of the alkali-soluble resin, and is decomposed, for example, hydrolyzed in the presence of an acid. Is a compound having the action of reducing or eliminating the alkali solubility control effect of the alkali-soluble resin, or the action of promoting the alkali solubility of the alkali-soluble resin.

Examples of such a dissolution control agent include acidic functional groups such as phenolic hydroxyl group and carboxyl group.
The compound substituted with the above-mentioned acid-decomposable group, the above-mentioned resin containing an acid-decomposable group and the like can be mentioned.

The dissolution control agent may be a low molecular weight compound or a high molecular weight compound, but preferred dissolution control agents include polyphenolic compounds such as bisphenol A, bisphenol F and bisphenol S, and carboxylic acid compounds such as hydroxyphenylacetic acid. The compound etc. which introduced the said acid-decomposable group can be mentioned.

Specific examples include compounds represented by the following chemical formula (a) or (b).

[0048]

[Chemical 1]

The acid-decomposable group-containing resin may be used as the polymer dissolution control agent.

In the resist composition (b), the dissolution control agent may be used alone or in admixture of two or more with respect to each of the low molecular weight compound and the high molecular weight compound (that is, the acid-decomposable group-containing resin). It is also possible to use a low molecular compound and a high molecular compound together.

The mixing ratio of the alkali-soluble resin, the radiation-sensitive acid generator and the dissolution control agent in the resist composition (b) is preferably 0.05 to 100 parts by weight of the radiation-sensitive acid generator per 100 parts by weight of the alkali-soluble resin. 20 parts by weight, more preferably 0.1 to 15 parts by weight, particularly preferably 0.
5 to 10 parts by weight, preferably 5 to 1 as a dissolution control agent
The amount is 50 parts by weight, more preferably 5 to 100 parts by weight, and particularly preferably 5 to 50 parts by weight.

When the amount of the radiation-sensitive acid generator is less than 0.05 parts by weight, it may be difficult to effectively cause a chemical change due to the acid catalyst generated by irradiation with radiation, while 20 parts by weight is added. When it exceeds, the resist composition (b)
There is a possibility that coating unevenness may occur when applying the toner, or scum or the like may occur during development. Further, if the amount of the dissolution control agent is less than 5 parts by weight, it is difficult to obtain the desired effect based on the dissolution control agent, and if it exceeds 150 parts by weight, the film-forming property, the film strength, etc. of the resist composition (b), etc. Tends to decrease.

The dissolution control agent is a resist composition (a).
The amount of the dissolution control agent added in this case is preferably 50 parts by weight or less with respect to 100 parts by weight of the acid-decomposable group-containing resin.

Crosslinking Agent Next, the crosslinking agent used in the resist composition (C) is a compound capable of crosslinking the alkali-soluble resin in the presence of an acid, for example, an acid generated by irradiation with radiation. Examples of such a cross-linking agent include compounds having one or more kinds of substituents (hereinafter referred to as "cross-linkable substituents") having cross-linking reactivity with an alkali-soluble resin. Examples of the crosslinkable substituent include

[0055]

[Chemical 2]

(Wherein l is 1 or 2, and when l is 1, X is any one selected from a single bond, --O--, --S--, --CO--O-- and --NH--. , L is 2,
X is trivalent N, Y is -O- or -S-, and m
Is an integer of 0 to 3, n is an integer of 1 to 3, and n + m is 4 or less. )

[0057]

[Chemical 3]

(Here, k is an integer of 0 or 1 or more, Z is any one selected from --O--, --CO--O-- or --CO--, and R ¹ and R ² are the same as each other. They may be different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ³ represents an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 12 carbon atoms or an aralkyl group having 7 to 14 carbon atoms.)

[0059]

[Chemical 4]

(Here, R ⁴ , R ⁵ and R ^{6, which} may be the same or different, each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

[0061]

[Chemical 5]

(Where k is an integer of 0 or 1 or more, R ¹
R ² and R ² may be the same or different from each other, and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁷ and R ⁸ represent an alkylol group having 1 to 5 carbon atoms or an alkoxyalkyl group. )

[0063]

[Chemical 6]

(Here, k is an integer of 0 or 1 or more, R ¹
R ² and R ² may be the same or different from each other, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ⁹ has any hetero atom selected from oxygen, sulfur or nitrogen, 3
Represents a divalent organic group capable of forming an 8-membered ring. ) Etc. can be mentioned.

Specific examples of such crosslinkable substituents include glycidyl ether group, glycidyl ester group, glycidylamino group, methoxymethyl group, ethoxymethyl group, benzyloxymethyl group, dimethylaminomethyl group, diethylaminomethyl group, Examples thereof include a dimethylolaminomethyl group, a diethylolaminomethyl group, a morpholinomethyl group, an acetoxymethyl group, a benzoyloxymethyl group, a formyl group, an acetyl group, a vinyl group and an isopropenyl group.

Specific examples of the compound having a crosslinkable substituent include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, novolac resin type epoxy compounds, resole resin type epoxy compounds and poly (hydroxy). styrene)
Epoxy compounds, methylol group-containing melamine compounds,
Methylol group-containing benzoguanamine compound, methylol group-containing urea compound, methylol group-containing phenol compound, alkoxyalkyl group-containing melamine compound, alkoxyalkyl group-containing benzoguanamine compound, alkoxyalkyl group-containing urea compound, alkoxyalkyl group-containing phenol compound, carboxymethyl group-containing Examples thereof include a melamine compound, a carboxymethyl group-containing benzoguanamine compound, a carboxymethyl group-containing urea compound, and a carboxymethyl group-containing phenol compound.

Of these compounds having a crosslinkable substituent, a methylol group-containing phenol compound, a methoxymethyl group-containing melamine compound, a methoxymethyl group-containing phenol compound, an acetoxymethyl group-containing phenol compound and the like are preferable, and more preferable is methoxy. It is a melamine compound containing a methyl group. Commercial products of melamine compounds containing methoxymethyl group include CYMEL300 and CYMEL.
301, CYMEL 303, CYMEL 305 (trade name, manufactured by Mitsui Cyanamid) and the like, and specific examples thereof include a compound (c) represented by the following general formula.

[0068]

[Chemical 7]

As the cross-linking agent, a resin in which the cross-linking substituent is introduced into the acidic functional group in the alkali-soluble resin to give the property as a cross-linking agent is also suitable. In that case, the introduction rate of the crosslinkable substituent is usually 5 to 60 mol%, preferably 10 to 50 mol%, and more preferably 15 to 40 mol% based on all the acidic functional groups in the alkali-soluble resin. Adjusted. When the introduction rate of the crosslinkable substituent is less than 5 mol%, it becomes difficult to cause a sufficient crosslink reaction,
The residual film rate tends to decrease, and the pattern tends to meander or swell. If it exceeds 60 mol%, the alkali solubility of the alkali-soluble resin tends to decrease and the developability tends to deteriorate.

In the resist composition (C), the crosslinking agent may be used alone or in combination of two or more kinds.

The mixing ratio of the alkali-soluble resin, the radiation-sensitive acid generator and the crosslinking agent in the resist composition (C) is preferably 0.05 to 100 parts by weight of the radiation-sensitive acid generator per 100 parts by weight of the alkali-soluble resin. 20 parts by weight, more preferably 0.1 to 15 parts by weight, particularly preferably 0.
5 to 10 parts by weight, preferably 5 to 95
It is preferably 15 to 85 parts by weight, more preferably 20 to 75 parts by weight. If the amount of the radiation-sensitive acid generator is less than 0.05 parts by weight, it may be difficult to effectively cause a chemical change due to the acid catalyst generated by irradiation with radiation, while if it exceeds 20 parts by weight, Uneven coating may occur when the resist composition (C) is applied,
Scum and the like may occur during development. Further, if the amount of the cross-linking agent is less than 5 parts by weight, the crosslinking reaction is usually insufficient, and the residual film rate may be reduced, and the pattern may meander or swell, while if it exceeds 95 parts by weight, The scum tends to increase and the developability tends to decrease.

Solvents used in the resist compositions (a) to (c) are
It is a solvent containing a ketone solvent. Such a solvent imparts excellent storage stability to the resist compositions (A) to (C) and the like, and is excellent even after a long time has passed after the preparation of the resist compositions (A) to (C). It is possible to give a resist pattern shape with good reproducibility.

The ketone solvent used in the present invention is a monoketone having 5 to 10 carbon atoms, and specifically, methyl butyl ketone, methyl isobutyl ketone, methyl amyl ketone, methyl isoamyl ketone, methylhexyl ketone, methyl octyl. Ketone, methyl decyl ketone,
Examples include ethyl propyl ketone, ethyl butyl ketone, ethyl pentyl ketone, dipropyl ketone, diisopropyl ketone, dibutyl ketone, dipentyl ketone, cyclopentanone, cyclohexanone, cyclooctanone, and the like, more preferably methyl amyl ketone, methyl. Examples thereof include isoamyl ketone and methylhexyl ketone.

In the present invention, the ketone solvent is preferably used in the same manner whether it is a single type or a mixture of several types of ketone compounds having different structures with respect to the type of alkyl group and the type of isomer. You can

In the present invention, another solvent is added to the ketone solvent, for example, less than 70% by weight, preferably 5% by weight of the total amount of the solvent.
It is possible to mix in the range of less than 0% by weight, particularly preferably less than 30% by weight.

Examples of the other solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and other ethylene glycol monoalkyl ethers; ethylene glycol monomethyl ether acetate, ethylene glycol. Ethylene glycol monoalkyl ether acetates such as monoethyl ether acetate; Diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether; propylene glycol monomethyl ether, propylene glycol monoethyl ether Propylene glycol monopropyl ether, propylene glycol monobutyl ether,
Propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether and other propylene glycol alkyl ethers; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate and other propylene glycol alkyl Ether acetates;
Methyl formate, ethyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, methyl propionate, ethyl propionate, butyl propionate, butanoic acid Methyl (methyl butyrate), ethyl butanoate (ethyl butyrate), propyl butanoate (propyl butyrate), isopropyl butanoate (isopropyl butyrate), ethyl 2-hydroxypropionate, 2-
Ethyl hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy-
Methyl 3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutylacetate, 3
-Methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3
-Methoxybutyl butyrate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, etc .; aromatic hydrocarbons such as toluene, xylene; N-methylpyrrolidone, N, N-dimethylformamide, N Examples include amide solvents such as -methylformamide and N, N-dimethylacetamide.

These solvents can be used alone or in admixture of two or more.

The amount of all the solvents to be added is usually 20 to 3000 parts by weight, preferably 50 to 3000, based on 100 parts by weight of the acid-decomposable group-containing resin or alkali-soluble resin.
Parts by weight, more preferably 100 to 2000 parts by weight.

If necessary, various additives such as a surfactant and a sensitizer may be added to the resist compositions (A) to (C).

The above-mentioned surfactant exhibits an action of improving the coating property and striation of the radiation-sensitive resin composition, the developability of the resist and the like. Examples of such a surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether,
In addition to polyoxyethylene glycol dilaurate and polyoxyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No.
75, No95 (manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.), F-top EF301, EF303, EF352 (Tochem Products), Megafac F171, F172, F173.
(Manufactured by Dainippon Ink and Chemicals), Florard FC430,
FC431 (Sumitomo 3M), Asahi Guard AG7
10, Surflon S-382, SC-101, SC-1
02, SC-103, SC-104, SC-105, S
C-106 (manufactured by Asahi Glass) and the like can be mentioned.

The content of the surfactant is usually 2 parts by weight or less per 100 parts by weight of all the resin components in the radiation sensitive resin composition.

The sensitizer absorbs the energy of radiation and transmits the energy to the radiation-sensitive acid generator,
It has the effect of increasing the amount of acid produced by it,
It has the effect of improving the sensitivity of the resist obtained using the composition of the present invention. Preferred specific examples of the sensitizer include acetone, benzene, acetophenones, benzophenones, naphthalene, biacetyl, eosin, rose bengal, pyrenes, anthracenes, and phenothiazines.

The compounding amount of the sensitizer is usually 50 parts by weight or less, preferably 30 parts by weight or less, per 100 parts by weight of all the resin components in the radiation-sensitive resin composition.

By adding a dye or a pigment, the effect of halation during irradiation of radiation can be mitigated, and by adding an adhesion aid, the adhesion to the substrate can be improved. Furthermore, examples of other additives include antihalation agents such as azo compounds and amine compounds, storage stabilizers, defoamers, and shape improvers.

The radiation-sensitive resin composition of the present invention contains a solution having a solid content of 5 to 50% by weight, for example, a pore size of 0.2.
It is prepared by filtering with a filter of about μm.

When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition is spin-coated,
A resist coating is formed by applying it onto a substrate such as a silicon wafer or a wafer covered with aluminum by means such as cast coating or roll coating, and the resist coating is irradiated with radiation so as to form a desired pattern. Irradiate. The radiation used at that time depends on the type of the radiation-sensitive acid generator used, i.e. ultraviolet rays such as i-rays; far-ultraviolet rays such as excimer lasers; x-rays such as synchrotron radiation; charged particle rays such as electron beams. Is appropriately selected and used.
Further, the radiation irradiation conditions such as the radiation dose are appropriately selected according to the compounding composition of the radiation sensitive resin composition, the kind of additives and the like.

In forming a resist pattern using the radiation-sensitive resin composition of the present invention, a protective film is formed on the resist film in order to prevent the influence of basic impurities contained in the working atmosphere. It can also be provided.

Further, in the present invention, in order to improve the apparent sensitivity of the resist film, it is preferable to perform baking after irradiation with radiation. The heating condition is usually 30 to 200 ° C., preferably 50 to 150 ° C., although it varies depending on the composition of the radiation-sensitive resin composition, the type of additives and the like.

Next, by developing with an alkali developing solution, a predetermined resist pattern is formed. Examples of the alkaline developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine,
Triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8
-Diazabicyclo- [5,4,0] -7-undecene,
An alkaline aqueous solution prepared by dissolving an alkaline compound such as 1,5-diazabicyclo- [4,3,0] -5-nonene to a concentration of usually 1 to 10% by weight, preferably 2 to 5% by weight is used. To be done.

Further, a proper amount of a water-soluble organic solvent such as methanol and ethanol and a surfactant can be added to the developing solution. When a developing solution composed of an alkaline aqueous solution is used, it is generally washed with water after development.

[0091]

EXAMPLES The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. In the examples, various characteristics were evaluated as follows.

Mw Tosoh Corp. GPC column (2 G2000H _XL ,
G3000H _XL 1 piece, G4000 _XL 1 piece)
The flow rate was 1.0 ml / min, the elution solvent was tetrahydrofuran, and the column temperature was 40 ° C. The coatable radiation-sensitive resin composition was spin-coated on a 6-inch silicon wafer and baked at 90 ° C. for 2 minutes, and then the formed resist film was observed. The case where there was no coating unevenness, cloudiness and foreign matter and the surface smoothness was high was defined as good. The sensitivity was defined as the radiation dose at which a line-and-space pattern with a sensitivity of 0.5 μm could be formed as designed. The unit is mJ / cm ² . The amount of film loss was calculated by measuring the film thickness of the resist film before and after development with α-step manufactured by Tencor.

Synthesis Example 1 30 g of polyhydroxystyrene was dissolved in tetrahydrofuran, 10 g of potassium t-butoxide was added, and di-t-butyl dicarbonate 60 was added under stirring at 0 ° C.
g was added dropwise and reacted for 4 hours. After the reaction was completed, this solution was dropped into water, and the precipitated resin was dried in a vacuum dryer at 50 ° C.
Dried overnight. The resin obtained has an Mw of 15,000.
From the result of NMR measurement, it was a structure in which 29% of hydrogen atoms of the phenolic hydroxyl group were substituted with t-butoxycarbonyl group. This resin is called resin (I).

Synthesis Example 2 300 g of pt-butoxystyrene, 30 g of styrene and 1.6 g of azobisisobutyronitrile were added to dioxane 3
It was dissolved in 30 and reacted for 12 hours in a nitrogen atmosphere while maintaining the internal temperature at 70 ° C. After the reaction, reprecipitation treatment is performed to remove unreacted monomers, and poly (pt-butoxystyrene-
A styrene) copolymer resin was obtained. Subsequently, this resin was hydrolyzed with an acid to obtain 180 g of a poly (p-hydroxystyrene-styrene) copolymer resin having an Mw of 18,000. When the copolymerization ratio was determined by NMR, it was p-hydroxystyrene: styrene = 85: 15 (molar ratio).
This resin is called resin (II).

Synthesis Example 3 15 g of bisphenol A was dissolved in tetrahydrofuran, 2 times the amount of di-t-butyl dicarbonate and 0.3 times the amount of triethylamine were added to the total number of acid groups, and the mixture was refluxed under reflux. Reacted for hours. Then, the reaction solution was added dropwise to water, and the resulting precipitate was dried in a vacuum dryer at 50 ° C. overnight. In this way, a dissolution control agent (a) shown later was obtained.

Synthesis Example 4 In the same manner as in Synthesis Example 3, instead of bisphenol A, a compound represented by a dissolution control agent (b) shown later in which t-butoxycarbonyl group is a hydrogen atom was used in Synthesis Example 3. The dissolution control agent (b) illustrated later was obtained by performing the operation of.

Examples 1 to 7 and Comparative Examples 1 to 4 The solvent shown in Table 1 was mixed with the other components shown in Table 1, dissolved, and microfiltered with a 0.2 μm filter to remove foreign matters. After removal, a radiation sensitive resin composition was obtained. The obtained radiation-sensitive resin composition was spin-coated on a 6-inch silicon wafer, baked at 100 ° C. for 2 minutes, and the formed resist film having a thickness of 1 μm was irradiated with radiation through a mask. Here, a KrF excimer laser irradiation device (MBK-400TL-N) manufactured by Admon Science Co. was used for irradiation. Thereafter, baking was performed at 110 ° C. for 2 minutes, development was performed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution for 60 seconds at 23 ° C., and then rinsed with water for 30 seconds to form a resist pattern. The formation of the resist pattern using the radiation-sensitive resin composition,
The same composition was tested immediately after preparation and 30 days after preparation. The obtained results are shown in Table 1.

The mixing ratio (weight ratio) of each component and solvent in each example is as follows. Examples 1 and 5 and Comparative Example 1: Resin 100, radiation-sensitive acid generator 3, solvent 420 Examples 2 to 4, 6 to 7 and Comparative Examples 2 to 4: Resin 100,
Radiation-sensitive acid generator 3, dissolution control agent or cross-linking agent 35, solvent 400 Further, the radiation-sensitive acid generator, dissolution control agent, cross-linking agent and solvent in Table 1 are as follows. Radiation-sensitive acid generator Triphenylsulfonium triflate Methoxyphenyl-bistrichloromethyl-s-triazine Dissolution control agent

[0099]

[Chemical 1]

Crosslinking agent

[0101]

[Chemical 7]

Solvent MAK: Methyl amyl ketone MIAK: Methyl isoamyl ketone PGDME: Propylene glycol dimethyl ether PGMEA: Propylene glycol monomethyl ether acetate BA: Butyl acetate EL: Ethyl lactate ECA: Ethylene glycol monoethyl ether acetate

[0103]

[Table 1]

[0104]

Industrial Applicability The radiation-sensitive resin composition of the present invention is excellent in sensitivity, resolution and the like, and is particularly excellent in coating properties by spin coating on a substrate having a large diameter, and is capable of stably performing fine processing. It is suitable as a chemically amplified resist composition that can be formed, has excellent storage stability, and forms a resist film that gives a good pattern shape. Further, the radiation-sensitive resin composition of the present invention can be applied to any of radiation such as ultraviolet rays such as i-rays, far ultraviolet rays such as excimer lasers, X-rays such as synchrotron radiation, and charged particle rays such as electron beams, It can be advantageously used as a radiation-sensitive resin composition for semiconductor device production, which is expected to be further miniaturized in the future.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area H01L 21/027

Claims (1)

[Claims] 1. A resist formed by dissolving an acid in a solvent by generating an acid by irradiation with radiation and changing the solubility of the irradiation portion in a developing solution by a chemical change due to the catalytic action of the acid. The radiation-sensitive resin composition, wherein the solvent is a solvent containing a monoketone compound having 5 to 10 carbon atoms.