JP2002099088A - Radiation sensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation sensitive composition effectively responding to electronic beams and excellent in roughness, etching resistance, and sensitivity and capable of forming a minute pattern highly accurately and stably. SOLUTION: This radiation sensitive composition contains the following (A) and (B): (A) a compound represented by formula (1) (Wherein, R1, R2 and R3 each independently represent an acid-dissociable functional group selected from the group consisting of hydrogen atom or a substituted methyl group, a 1-substituted ethyl group, a 1-substituted-n-propyl group, a 1-branched alkyl group, a silyl group, an acyl group, a 1-substituted alkoxymethyl group and a cyclic acid-dissociable group. At least one of R1, R2 and R3 is an acid- dissociable functional group). (B) a compound generating an acid by irradiation with radioactive rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a radiation-sensitive composition suitable for fine processing. More specifically, the present invention relates to a radiation-sensitive composition particularly suitable for forming a fine pattern by irradiation with an electron beam.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, design rules in lithography have been rapidly miniaturized in order to obtain a higher degree of integration of integrated circuits. The development of a lithography process that can stably perform lithography has been strongly promoted. However, with a conventional method using a KrF or ArF excimer laser, it is difficult to form a fine pattern with a size of 100 nm or less with high accuracy. Therefore, a method using an electron beam has been proposed.

As electron beam resist materials used in such ultrafine processing, (1) methacrylic main chain-cutting positive resists such as PMMA (polymethyl methacrylate), and (2) cross-linking having a chloromethyl group and an epoxy group. Negative resist, (3) a chemically amplified positive resist having a polyhydroxystyrene resin (KrF excimer resin) and a novolak (i-line resin) partially protected with an acid dissociable functional group and an acid generator; (4) Positive and negative resists containing (amorphous) organic low-molecular-weight compounds having a thin film forming ability such as calixarene and fullerene. The positive resist (1) is excellent in resolution, but has problems in etching resistance and sensitivity and is difficult to put into practical use. Poly-t-butyl α-chloromethylstyrene excellent in the balance between resolution and sensitivity (Japanese Patent Application Laid-Open No. 2000-147777), and a patent application in which atoms (N, O, S) which are easily cut by an electron beam at the terminal of the resin are introduced Japanese Unexamined Patent Publication No. Hei 11-29612), and although the sensitivity has been improved, both the sensitivity and the etching resistance have not reached a practical level. The negative resist of (2) has low sensitivity and an increased molecular weight due to electron beam irradiation, and therefore swells in a developing solution and is difficult to apply to a fine process. Although the sensitivity is high in the chemically amplified positive resist (3), since a resin is used, when a fine pattern is formed, film surface roughness (hereinafter referred to as roughness) becomes a problem. Regarding the resist (4), JP-A-11-322656,
JP-A-11-72916 and JP-A-9-236
No. 919 discloses a resist using calixarene. This resist is excellent in etching resistance, but structurally has very strong interaction between molecules and has poor solubility in a developing solution, so that a satisfactory pattern cannot be obtained.

[0004] Japanese Patent Application Laid-Open No.
JP-A-2111862, JP-A-10-282649, JP-A-11-143074 and JP-A-11-118
JP-A-258796 discloses a resist using fullerene. This resist has good etching resistance, but its coatability and sensitivity have not reached practical levels.

[0005] Other than calixarenes and fullerenes, 1,3,5-
Tris [4- (2-t-butoxycarbonyloxy) phenyl] benzene (J. Photo Sci and and
Tech VOL12 No2 375-376 (19
99))) A chemically amplified resist has been proposed, but it has not reached a practical level due to problems in applicability, adhesion to a substrate, resolution, and sensitivity.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a radiation-sensitive composition suitable for fine processing. Another object of the present invention is to provide a radiation-sensitive composition which is excellent in roughness, etching resistance and sensitivity and can form a fine pattern with high accuracy and stability. Still another object of the present invention is to provide a radiation-sensitive composition as a chemically amplified positive resist suitable for an electron beam that effectively responds to an electron beam. Still other objects and advantages of the present invention will become apparent from the following description.

[0007]

According to the present invention, the above objects and advantages of the present invention are as follows: (A) The following formula (1)

[0008]

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(Wherein R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituted methyl group, a 1-substituted ethyl group, a 1-substituted n-propyl group, a 1-branched alkyl group,
An acid dissociable functional group selected from the group consisting of a silyl group, an acyl group, a 1-substituted alkoxymethyl group, and a cyclic acid dissociable group. However, at least one of R ¹ , R ² and R ³ is an acid dissociable functional group. And (B) a compound capable of generating an acid upon irradiation.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. (A) Specific Compound The specific compound used in the present invention has at least one compound.
It is a compound having two acid dissociable functional groups. The acid dissociable functional group is a substituted methyl group, a 1-substituted ethyl group, a 1-substituted n-propyl group, a 1-branched alkyl group, a silyl group,
An acyl group, a 1-substituted alkoxyl group or a cyclic acid dissociable group.

Specific examples of the substituted methyl group include methoxymethyl, methylthiomethyl, ethoxymethyl, ethylthiomethyl, methoxyethoxymethyl, benzyloxymethyl, benzylthiomethyl, phenacyl, and 4-bromophenacyl. Group, 4-methoxyphenacyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, i-propoxycarbonylmethyl group, n-butoxycarbonylmethyl group, t-butoxycarbonylmethyl group, etc. Can be mentioned.

Specific examples of the 1-substituted ethyl group include 1-substituted ethyl group.
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-cyclopentyloxyethyl group, 1-cyclohexyloxyethyl group, 1-phenylethyl group and 1,1-diphenylethyl group.

The 1-substituted n-propyl group includes, for example, a 1-methoxy-n-propyl group and a 1-ethoxy-n-propyl group. Examples of the 1-branched alkyl group include an i-propyl group, sec-
Examples thereof include a butyl group, a t-butyl group, a 1,1-dimethylpropyl group, a 1-methylbutyl group and a 1,1-dimethylbutyl group. Examples of the silyl group include a trimethylsilyl group, an ethyldimethylsilyl group, a methyldiethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a t-butyldiethylsilyl group,
-Butyldiphenylsilyl group, tri-t-butylsilyl group and triphenylsilyl group.

As the acyl group, for example, an acetyl group,
Phenoxyacetyl group, propionyl group, butyryl group,
Examples include a heptanoyl group, a hexanoyl group, a valeryl group, a pivaloyl group, an isovaleryl group, a lauryloyl group, an adamantyl group, a benzoyl group and a naphthoyl group. Examples of the 1-substituted alkoxymethyl group include, for example, 1-cyclopentylmethoxymethyl,
Cyclopentylethoxymethyl, 1-cyclohexylmethoxymethyl, 1-cyclohexylethoxyethyl, 1
-Cyclooctylmethoxymethyl and 1-adamantylmethoxymethyl groups.

Further, examples of the cyclic acid dissociable group include cyclopentyl, cyclohexyl, cyclohexenyl, 4-methoxycyclohexyl, tetrahydropyranyl, tetrahydrofuranyl, tetrahydrothiopyranyl, and tetrahydrothiofuranyl. Group, 4-methoxytetrahydropyranyl group and 4-methoxytetrahydrothiopyranyl group. Among these acid dissociable groups, a t-butoxycarbonylmethyl group,
Preferred are a 1-methoxyethyl group, a 1-ethoxyethyl group, a 1-cyclohexyloxyethyl group, a t-butyl group, a trimethylsilyl group, a tetrahydropyranyl group and a 1-cyclohexylmethoxymethyl group.

Further, the radiation-sensitive composition of the present invention includes a compound (hereinafter, also referred to as “other compound”) corresponding to a compound in which R ¹ , R ² and R ³ are all hydrogen atoms in the above formula (1). ) May be included. R ¹ and R ² of the specific compound
And R ^1, the proportion of acid-dissociable functional group of the specific compound in the whole group corresponding to R ² and R ³ in R ³ and the other compounds is preferably at 1 to 99 mol%, more preferably 5 To 85 mol%, particularly preferably 10 to 7 mol%.
5 mol%. If the amount is less than 1 mol%, the resolution as a resist may decrease.
The sensitivity as a resist, the resolution, and the adhesiveness to the substrate may be reduced.

The specific compound used in the present invention is
In the formula (1), R¹, R^TwoAnd R ^ThreeOne of
Is a compound in which two compounds are acid dissociable functional groups
Is preferred from the viewpoint of the ability to form(B) Acid generator The (B) acid generator used in the present invention is suitable for radiation
More direct or indirect (Ionized by electron beam irradiation
(E.g., reactions involving electrons generated from contaminated substances)
Consists of a compound that grows. As such an acid generator,
Although not limited to, for example, onium salt compounds, sulfonium
Honimide compounds, disulfone compounds, oximes
Sulfonate compounds and the like can be mentioned. these
(B) Examples of the acid generator are shown below. Examples of the onium salt compound include the following formula (2):
(3)

[0018]

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[0019]

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(In the formulas (2) and (3), R ^{4 to} R ¹⁸
Is the same or different and represents a hydrogen atom, a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkoxy group, a hydroxyl group or a halogen atom.
X represents an alkyl group, an aryl group, a halogen-substituted alkyl group or a halogen-substituted aryl group).

Specific examples of the onium salt compound include the following compounds. a. Sulfonium salt triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, diphenyl-4-t- Butylphenylsulfonium trifluoromethanesulfonate, diphenyl-2,
4,6-trimethylphenylsulfonium trifluoromethanesulfonate, diphenyl-4-t-butoxyphenylsulfonium trifluoromethanesulfonate,
Diphenyl-4-t-butoxyphenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-4
-Hydroxyphenylsulfonium trifluoromethanesulfonate, bis (4-fluorophenyl) -4-hydroxyphenylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium nonafluoro-n-butanesulfonate, bis (4-hydroxyphenyl) -phenylsulfonium Trifluoromethanesulfonate, tri (4-methoxyphenyl) sulfonium trifluoromethanesulfonate, tri (4-fluorophenyl) sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfoniumbenzenesulfonate, diphenyl-2,4,6- Trimethylphenyl-p-toluenesulfonate, diphenyl-2,4,6-trimethyl Phenylsulfonium-2-trifluoromethylbenzenesulfonate, diphenyl-
2,4,6-trimethylphenylsulfonium-4-trifluoromethylbenzenesulfonate, diphenyl-
2,4,6-trimethylphenylsulfonium-2,4-
Difluorobenzenesulfonate, diphenyl-2,4,
6-trimethylphenylsulfonium hexafluorobenzenesulfonate, diphenylnaphthylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium-p-toluenesulfonate, triphenylsulfonium 10-camphorsulfonate and diphenyl-4-hydroxyphenylsulfonium 10-camphorsulfonate.

B. Iodonium salt bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium par Fluoro-n-octanesulfonate, bis (4-t-
Butylphenyl) iodonium p-toluenesulfonate, bis (4-t-butylphenyl) iodoniumbenzenesulfonate, bis (4-t-butylphenyl) iodonium-2-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) Iodonium-
4-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium-2,4 difluorobenzenesulfonate, bis (4-t-butylphenyl) iodonium hexafluorobenzenesulfonate, bis (4-t-butylphenyl) Iodonium 1
0-camphorsulfonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium benzenesulfonate, diphenyliodonium 10-camphorsulfonate,
Diphenyliodonium-2-trifluoromethylbenzenesulfonate, diphenyliodonium-4-trifluoromethylbenzenesulfonate, diphenyliodonium-2,4 difluorobenzenesulfonate, diphenyliodonium hexafluorobenzenesulfonate, di (4-trifluoromethylphenyl) iodonium trifluoro Romethanesulfonate, di (4-trifluoromethylphenyl) iodonium nonafluoro-n
-Butanesulfonate, di (4-trifluoromethylphenyl) iodonium perfluoro-n-octanesulfonate, di (4-trifluoromethylphenyl) iodonium p-toluenesulfonate, di (4-trifluoromethylphenyl) iodoniumbenzenesulfonate and Di (4-trifluoromethylphenyl) iodonium 10-camphorsulfonate. Sulfonimide compound: the following formula (4)

[0023]

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(In the formula (4), V is an alkylene group,
R ¹⁹ represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group, or a halogen-substituted aryl group. ).

Specific examples of such a sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, and N- ( Trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthylimide,
N- (10-camphorsulfonyloxy) succinimide, N- (10-camphorsulfonyloxy) phthalimide, N- (10-camphorsulfonyloxy)
Diphenylmaleimide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-
2,3-dicarboximide, N- (10-camphorsulfonyloxy) naphthylimide, N- (n-octanesulfonyloxy) bicyclo [2.2.1] hept-5
-Ene-2,3-dicarboximide, N- (n-octanesulfonyloxy) naphthylimide, N- (p-toluenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3- Dicarboximide, N- (p-
Toluenesulfonyloxy) naphthylimide, N- (2
-Trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (2-trifluoromethylbenzenesulfonyloxy) naphthylimide, N- (4- Trifluoromethylbenzenesulfonyloxy) bicyclo [2.
2.1] Hept-5-ene-2,3-dicarboximide, N- (4-trifluoromethylbenzenesulfonyloxy) naphthylimide, N- (perfluorobenzenesulfonyloxy) bicyclo [2.2.1] Hept-5
Ene-2,3-dicarboximide, N- (perfluorobenzenesulfonyloxy) naphthylimide, N-
(1-Naphthalenesulfonyloxy) bicyclo [2.2.
1] hept-5-ene-2,3-dicarboximide,
N- (1-naphthalenesulfonyloxy) naphthylimide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-
Dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) naphthylimide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.
1] Hept-5-ene-2,3-dicarboximide and N- (perfluoro-n-octanesulfonyloxy) naphthylimide. Disulfone compound: the following formula (5)

[0026]

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(In the formula (5), R ²⁰ and R ²¹ may be the same or different, and may be a linear, branched or cyclic alkyl group which may be substituted, an aryl group which may be substituted, A heteroaryl group which may be substituted or an aralkyl group which may be substituted). Specific examples of the disulfone compound include diphenyldisulfone, di (4-methylphenyl) disulfone, dinaphthyldisulfone, di (4-t-butylphenyl) disulfone, di (4-hydroxyphenyl) disulfone, and di (3- (Hydroxynaphthyl) disulfone, di (4-fluorophenyl) disulfone,
Di (2-fluorophenyl) disulfone and di (4
-Trifluoromethylphenyl) disulfone and the like. Oxime sulfonate compound The following formula (6)

[0028]

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(In the formula (6), R ²² and R ²³ are an optionally substituted linear, branched or cyclic alkyl group,
An optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted aralkyl group].

Specific examples of such oxime sulfonate compounds include α- (methylsulfonyloxyimino)
-Phenylacetonitrile, α- (methylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α-
Examples thereof include (propylsulfonyloxyimino) -4-methylphenylacetonitrile and α- (methylsulfonyloxyimino) -4-bromophenylacetonitrile.

The acid generator (B) in the present invention may be used alone or in combination of two or more. In the present invention, the amount of the acid generator used is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, and still more preferably 1 to 15 parts by weight, per 100 parts by weight of the specific compound (A). Parts by weight.

If the amount is less than 0.1 part by weight, sensitivity and resolution tend to decrease, while if it exceeds 30 parts by weight, the pattern cross-sectional shape as a resist tends to decrease. Acid Diffusion Control Agent In the present invention, further, acid diffusion having an action of controlling an undesired chemical reaction in an unexposed region by controlling a diffusion phenomenon of an acid generated from an acid generator by irradiation with radiation in a resist film. It is more preferable to add a control agent. By using such an acid diffusion controller, the storage stability of the resist composition is improved, the resolution is improved, and the storage time before electron beam irradiation (PCD),
It is possible to suppress a change in the line width of the resist pattern due to a change in the withdrawal time (PED) after the electron beam irradiation, and the process stability is extremely excellent. Examples of such an acid diffusion controller include electron beam radiolytic base compounds such as a basic compound containing a nitrogen atom, a basic sulfonium compound, and a basic iodonium compound. As such a nitrogen-containing organic compound, for example, the following formula (7)

[0033]

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(In the formula (7), R ²⁴ , R ²⁵ and R
²⁶ independently represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and the alkyl group, the aryl group and the aralkyl group may be substituted with a functional group such as a hydroxy group. ) (Hereinafter referred to as “nitrogen-containing compound (I)”), a diamino compound having two nitrogen atoms in the same molecule (hereinafter “nitrogen-containing compound (I)”).
I) ". ), A diamino polymer having three or more nitrogen atoms (hereinafter, referred to as “nitrogen-containing compound (III)”), an amide group-containing compound, a urea compound, a nitrogen-containing heterocyclic compound, and the like.

Examples of the nitrogen-containing compound (I) include, for example, triethylamine, tri-n-propylamine, tri-n
-Butylamine, tri-n-pentylamine, tri-n
-Hexylamine, tri-n-heptylamine, tri-
n-octylamine, tri-n-nonylamine, tri-
n-decylamine, triethanolamine, dimethyl-
Trialkylamines such as n-dodecylamine and dicyclohexylmethylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine And aromatic amines such as triphenylamine and 1-naphthylamine.

As the nitrogen-containing compound (II), for example,
Ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetrakis (2-hydroxypropyl) ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis (4'-aminophenyl) propane, 2- (3'-aminophenyl) -2 −
(4'-aminophenyl) propane, 2- (4'-aminophenyl) -2- (3'-hydroxyphenyl) propane, 2- (4'-aminophenyl) -2- (4'-hydroxyphenyl) propane 1,4-bis [1 ′-(4 ″-
Aminophenyl) -1′-methylethyl] benzene and 1,3-bis [1 ′-(4 ″ -aminophenyl) -1 ′
-Methylethyl] benzene and the like.

Examples of the nitrogen-containing compound (III) include polymers of polyethyleneimine, polyallylamine, and dimethylaminoethylacrylamide. Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone and N-methylpyrrolidone. Can be mentioned. As urea compounds,
For example, urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea and tri-n-
Butylthiourea and the like can be mentioned.

Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, benzimidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole and 2-phenylbenzimidazole; pyridine, 2-methylpyridine, -Methylpyridine, 2-
Ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, ^2,2, 2 ^,, - Toripirijin, nicotine,
In addition to pyridines such as nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline and acridine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethyl Piperazine and 1,4-diazabicyclo [2.2.2] octane and the like can be mentioned. Examples of the radiolytic base compound include compounds represented by the following formulas (8) and (9).

[0039]

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[0040]

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In the formula (8), R ^{27 to} R ²⁹ may be the same or different and represent a hydrogen atom, an alkyl group, an alkoxyl group, a hydroxyl group or a halogen atom. In the formula (9), R ^{30 to} R ³¹ may be the same or different and represent a hydrogen atom, an alkyl group, an alkoxyl group or a halogen atom. Z ^- is a hydroxyl group, salicylate, or RCOO ^-
(R = C ¹ -C ¹⁰ alkyl, aryl or alkylaryl).

Specifically, triphenylsulfonium hydroxide, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium salicylate, bis (4-t-butylphenyl) iodonium salicylate and 4-t- Butylphenyl-
4-hydroxyphenyliodonium salicylate and the like can be mentioned. The acid diffusion controllers can be used alone or in combination of two or more.

The amount of the acid diffusion controller in the present invention is as follows:
(A) Per 100 parts by weight of the specific compound, preferably
0.001 to 10 parts by weight, more preferably 0.005 to 5 parts by weight
Parts by weight, more preferably 0.01 to 3 parts by weight.
In this case, if the compounding amount of the acid diffusion controller is less than 0.001 parts by weight, the resolution, pattern shape, dimensional fidelity, etc. tend to be deteriorated depending on the process conditions, and furthermore, radiation irradiation such as electron beam irradiation is likely. Baking after irradiation (hereinafter,
It is called "bake after irradiation". ) (Po)
If the st Exposure Time Delay is long, the pattern shape tends to deteriorate in the upper layer portion of the pattern. On the other hand, when the compounding amount of the basic compound exceeds 10 parts by weight, the sensitivity as a resist, the developability of an unexposed portion, and the like tend to decrease. Additives Further, the radiation-sensitive composition of the present invention includes a dissolution controlling agent,
Various additives such as a dissolution promoter, a sensitizer, and a surfactant can be blended.

When the solubility of the specific compound (A) in a developing solution such as an alkali is too high, the dissolution controlling agent controls the solubility to appropriately reduce the dissolution rate of the low-molecular compound during development. It is a component which has. As such a dissolution controlling agent, a dissolution controlling agent that does not chemically change in the steps of baking, irradiation of radiation, development and the like of the resist film is preferable. Examples of the dissolution controlling agent include aromatic hydrocarbons such as naphthalene, phenanthrene, anthracene, and acenaphthene; ketones such as acetophenone, benzophenone, and phenylnaphthyl ketone; sulfones such as methylphenyl sulfone, diphenyl sulfone, and dinaphthyl sulfone; Can be mentioned. These dissolution controlling agents can be used alone or in combination of two or more.

The amount of the dissolution controlling agent used is (A)
The amount is appropriately adjusted depending on the type of the specific compound, but is preferably 30 parts by weight or less, more preferably 10 parts by weight or less, per 100 parts by weight of the specific compound (A). When the solubility of the specific compound (A) in a developing solution such as an alkali is too low, the dissolution promoter enhances the solubility of the specific compound to appropriately increase the dissolution rate of the low-molecular compound during development. It is. As such a dissolution accelerator, one that does not chemically change in steps such as baking of a resist film, electron beam irradiation, and development is preferable.

Examples of the dissolution promoter include low-molecular-weight phenolic compounds having about 2 to 6 benzene rings, and specific examples thereof include bisphenols and tris (hydroxyphenyl) methane. Can be mentioned. These dissolution promoters can be used alone or in combination of two or more. The amount of the dissolution promoter is appropriately adjusted depending on the type of the specific compound (A) used.
Preferably, it is at most 30 parts by weight, more preferably at most 10 parts by weight.

The sensitizer has the function of absorbing the energy of the irradiated radiation and transmitting the energy to the acid generator, thereby increasing the amount of acid generated, thereby improving the apparent sensitivity of the resist. It is a component that causes Such sensitizers include, for example, benzophenones, biacetyls,
Pyrenes, phenothiazines, fluorenes and the like can be mentioned. These sensitizers can be used alone or
More than one species can be used together. The amount of the sensitizer is preferably 30 parts by weight or less, more preferably 10 parts by weight or less, per 100 parts by weight of the specific compound (A). The surfactant is a component having an effect of improving the coating property, striation, developability as a resist, and the like of the radiation-sensitive composition of the present invention.

As such a surfactant, any of anionic, cationic, nonionic and amphoteric surfactants can be used. Among these, preferred surfactants are nonionic surfactants. Examples of nonionic surfactants include polyoxyethylene higher alkyl ethers, polyoxyethylene higher alkyl phenyl ethers, higher fatty acid diesters of polyethylene glycol, and the like, as well as FPTOP (Tochem Products). ), Megafac (Dainippon Ink and Chemicals), Florard (Sumitomo 3M), Asahi Guard, Surflon (from Asahi Glass), Pepole (Toho Chemical), KP (Shin-Etsu Chemical) And Polyflow (manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.).

The amount of the surfactant is preferably 2 parts by weight or less as an active ingredient of the surfactant per 100 parts by weight of the specific compound (A). In addition, by blending a dye or a pigment, the latent image in the exposed area can be visualized, and the effect of halation at the time of exposure can be reduced.By blending an adhesion aid, the adhesion to the substrate can be improved. it can. Solvent When the radiation-sensitive composition of the present invention is used, it is dissolved in a solvent such that the solid content concentration is preferably 1 to 20% by weight, and then, for example, filtered through a filter having a pore size of about 0.2 μm. To prepare a resist solution.

Examples of the solvent used in the radiation-sensitive composition include ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether. Ethylene glycol monoalkyl ethers such as ether, propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether. Lactate esters such as methyl lactate and ethyl lactate ; Methyl acetate, ethyl acetate, propyl acetate, such as aliphatic carboxylic acid esters of butyl acetate; methyl 3-methoxypropionate, 3-methoxy propionic acid ethyl, methyl 3-ethoxypropionate,
Other esters such as ethyl 3-ethoxypropionate; aromatic hydrocarbons such as toluene and xylene;
Examples thereof include ketones such as heptanone, 3-heptanone, 4-heptanone, and cyclohexanone, and cyclic ethers such as tetrahydrofuran and dioxane. These solvents can be used alone or in combination of two or more. When forming a resist pattern from the radiation-sensitive composition of the formation the present invention resist pattern, the solution of the radiation-sensitive composition, spin coating, cast coating, by an appropriate application method roll coating, e.g. After coating on a substrate such as a silicon wafer or a wafer coated with aluminum to form a resist film, drawing is performed with radiation, preferably an electron beam.

The drawing conditions and the like are appropriately selected according to the composition of the radiation-sensitive composition and the like. In the present invention, in order to stably form a high-precision fine pattern in radiation drawing, it is preferable to perform baking after drawing. The heating conditions vary depending on the composition of the radiation-sensitive composition and the like, but are preferably 40 to 200C, more preferably 50 to 150C. Next, a predetermined resist pattern is formed by developing the drawn resist film with an alkaline developer.

Examples of the alkali developer include mono-, di- or tri-alkylamines, mono-,
Di- or tri-alkanolamines, heterocyclic amines, at least one of alkaline compounds such as tetramethylammonium hydroxide, choline and the like, preferably 1 to 10% by weight, more preferably 1 to 5% by weight. An alkaline aqueous solution dissolved to a concentration is used. Further, an appropriate amount of an alcohol such as methanol, ethanol, or isopropyl alcohol or a surfactant can be added to the alkali developer. When using a developer composed of such an alkaline aqueous solution,
Generally, after development, it is washed with water.

[0053]

Embodiments of the present invention will be described below more specifically with reference to examples. However, the present invention is not limited to these embodiments.

[0054]

EXAMPLES (A) Synthesis of Specific Compound

Synthesis Example 1 Pyridinium-p-toluenesulfonate (0.05 g) was added to a solution of 3 g of 1,3,5-tris (4-hydroxyphenyl) benzene (manufactured by Aldrich) in 20% by weight of propylene glycol monomethyl ether acetate to obtain a homogeneous solution. did. 1.00 g of ethyl vinyl ether was added dropwise to the solution, and the mixture was stirred at room temperature for 10 hours. After adding 0.02 g of triethylamine to the reaction solution, reprecipitation purification was repeated with a large amount of water. Finally, drying under reduced pressure was performed to obtain 3.9 g of a compound (A-1) in which a hydroxy group was 49% ethoxyethylated.

Synthesis Example 2 To a solution of 3 g of 1,3,5-tris (4-hydroxyphenyl) benzene (manufactured by Aldrich) in 20% by weight of butyl acetate, 0.36 g of tetrabutylammonium bromide was added.
An aqueous solution in which 1.59 g of potassium carbonate was dissolved in 15 g of ion-exchanged water was slowly added with stirring at room temperature. 2.2 g of t-butyl bromoacetate was added thereto, followed by stirring at 70 ° C. for 6 hours. After cooling, the lower layer was extracted and discarded. The upper layer was added to a large amount of water, and reprecipitation purification was repeated. Finally, drying under reduced pressure was performed to obtain 4.0 g of a compound (A-2) in which the hydroxy group was 40% t-butoxycarbonylmethylated.

Synthesis Example 3 Pyridinium-p-toluenesulfonate (0.05 g) was added to a solution of 3 g of 1,3,5-tris (4-hydroxyphenyl) benzene (manufactured by Aldrich) in 20% by weight of propylene glycol monomethyl ether acetate to obtain a homogeneous solution. did. Cyclohexyl vinyl ether 1.1 in solution
g was added dropwise and stirred at room temperature for 10 hours. After adding 0.02 g of triethylamine to the reaction solution, reprecipitation purification was repeated with a large amount of water. Finally, drying under reduced pressure is carried out to reduce the number of hydroxy groups to 2
8% cyclohexyloxyethylated compound (A-
2.8 g of 3) was obtained.

Synthesis Example 4 A solution of 3 g of 1,3,5-tris (4-hydroxyphenyl) benzene (manufactured by Aldrich) in 20% by weight of pyridine was added with t.
0.8 g of -butyl chloride was added dropwise, and the mixture was stirred at room temperature for 3 hours. The reaction solution was repeatedly purified by reprecipitation with a large amount of water. Lastly, drying under reduced pressure was performed to obtain 2.7 g of a compound (A-4) in which the hydroxy group was 32% t-butylated.

Synthesis Example 5 Polyhydroxystyrene (VP8000 Nippon Soda Co., Ltd.)
Mw 9000 Mw / Mn = 1.1) Pyridinium-p-toluenesulfonate was added to 10 g of a 20% by weight solution of propylene glycol monomethyl ether acetate.
15 g was added to make a homogeneous solution. 1.8 g of ethyl vinyl ether was added dropwise to the solution, and the mixture was stirred at room temperature for 10 hours. After adding 0.05 g of triethylamine to the reaction solution, reprecipitation purification was repeated with a large amount of water. Lastly, the compound (A-) in which the hydroxy group was ethoxyethylated at 30% was dried under reduced pressure.
5) was obtained in an amount of 11.5 g.

Examples 1 to 6 and Comparative Example 1 After mixing the components shown in Table 1 (parts are based on weight) to obtain a uniform solution, a 0.2 μm-pore-size Teflon (registered trademark) membrane filter was used. Then, the mixture was filtered to remove foreign substances, thereby preparing a radiation-sensitive composition.

Each of the obtained radiation-sensitive compositions was spin-coated on a 6-inch diameter silicon wafer,
By baking at 100 ° C., a resist film having a thickness of 0.3 μm was formed, and the resist film was exposed to an electron beam using a simple electron beam direct writing apparatus (50 keV, current density 4.5 amps). . After the exposure, baking (PEB) is performed at 50 to 100 ° C. for 1 minute, and development is performed at 23 ° C. for 60 seconds by a paddle method using a 2.38 wt% aqueous solution of tetramethylammonium hydroxide. For 30 seconds and dried to form a positive resist pattern. Table 2 shows the evaluation results of the obtained resist patterns.
Shown in

Each measurement and evaluation in Examples and Comparative Examples was performed by the following methods. The exposure for forming a line-and-space pattern (1L1S) having a sensitivity design dimension of 0.15 μm with a line width of 1: 1 was defined as the optimum exposure, and the sensitivity was evaluated based on the optimum exposure. Resolution The dimension of the smallest resist pattern that was resolved when exposed at the optimal exposure was measured and defined as the resolution. For a line-and-space pattern (1L1S) having a designed surface roughness of 0.15 μm, the cross-sectional dimension of the line pattern was measured with a scanning electron microscope, and the minimum dimension was Lin,
The maximum dimension is Lout, and (Lout-Lin) is Ld
Was evaluated according to the following criteria according to the value of Ld.

Ld is less than 0.01 μm: good Ld is 0.01 μm or more: bad Each component used in Examples and Comparative Examples is as follows. (B) Acid generator B-1: triphenylsulfonium trifluoromethanesulfonate, B-2: diphenyliodonium trifluoromethanesulfonate, B-3: N- (trifluoromethylsulfonyloxy)
Naphthylimide, acid diffusion controller C-1: ^{trioctylamine, C-2: 2,2, 2} ,, - Toripirijin, solvent D-1: Propylene glycol monomethyl ether acetate, D-2: ethyl lactate,

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

EFFECT OF THE INVENTION The radiation-sensitive composition of the present invention has excellent sensitivity and resolution, has a small surface roughness, and has a line-and-
For both the space pattern and the isolated pattern, a fine pattern can be formed with high accuracy and stability. The radiation-sensitive composition of the present invention can be very suitably used as a chemically amplified positive resist in the manufacture of semiconductor devices in which miniaturization is expected to proceed in the future.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiaki Kadota 3-5-19-1 Senriyama Higashi, Suita-shi, Osaka Yuniwa Excel 410 (72) Inventor Toshiyuki Kai 1-4-303 Morikayamacho, Yokkaichi-shi, Mie F-term (Reference) 2H025 AA03 AB16 AC04 AC08 AD03 BE00 BE07 BE10 BF29 BG00 CB45 FA17

Claims (1)

[Claims] (A) The following formula (1): (Wherein, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituted methyl group, a 1-substituted ethyl group, a 1-substituted n-propyl group, a 1-branched alkyl group, a silyl group, an acyl group Group, a 1-substituted alkoxymethyl group and a cyclic acid-dissociable group, provided that at least one of R ¹ , R ² and R ³ is an acid-dissociable functional group A radiation-sensitive composition comprising a compound represented by the formula (I): (B) and a compound capable of generating an acid upon irradiation with radiation.