JP2002156762A - Positive radiation-sensitive composition, and method for producing resist pattern using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high sensitivity positive radiation-sensitive composition, having resolution which enables subquarter micron patterning. SOLUTION: The positive radiation-sensitive composition contains (a) a compound, having an alkali-soluble group protected with an acid releasable group of formula (1) (wherein R1-R3 are each alkyl, substituted alkyl, cycloalkyl, an aromatic ring or an aromatic ring having an electron donative group, at least one of R1-R3 is the aromatic ring, having an electron donative group, and R1-R3 may each be the same or different) and (b) an acid-generating agent which generates acid, when irradiated with radiation. A method for producing a resist pattern using the composition is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive radiation-sensitive composition used for producing semiconductor integrated circuits, lithography masks and the like.

[0002]

2. Description of the Related Art In recent years, in fields such as the manufacture of semiconductor circuits and lithography masks, patterns have been miniaturized with an increase in the degree of integration. In order to realize this, a higher resolution resist material has been required, and it has become necessary to process a sub-quarter micron pattern of 0.25 μm or less with high sensitivity. With conventional lithography using a light source with a relatively long wavelength, it is difficult to perform such fine processing, and X-rays and electron beams with higher energy,
Lithography using vacuum ultraviolet light is being studied,
There is a demand for resists corresponding to these light sources.

As a well-known resist material corresponding to such an exposure light source and having characteristics of high sensitivity and high resolution, a chemically amplified resist has been actively studied. A chemically amplified resist is a resist having a mechanism in which an acid is generated in an exposed portion by the action of a photoacid generator, and the solubility of the exposed portion is changed by the catalytic action of the acid. Conventionally, among such chemically amplified resists, those showing relatively good resist performance include an alkali-soluble group in an alkali-soluble resin of t-type.
A resin protected with an acid-decomposable group such as a tertiary ester group such as a butyl group, a t-butoxycarbonyl group, or an acetal group is used.

[0004]

However, the resolution and the sensitivity are in a contradictory relationship, and there is a drawback that the sensitivity is not sufficient to obtain a resolution for processing a sub-quarter micron pattern.

[0005]

The present invention comprises a) a compound in which a carboxyl group is protected by an acid leaving group represented by the general formula (1) and b) an acid generator which generates an acid upon irradiation with radiation. And a method of manufacturing a resist pattern using the same.

[0006]

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(R ^{1 to} R ³ are represented by any of an alkyl group, a substituted alkyl group, a cycloalkyl group, an aromatic ring and an aromatic ring having an electron donating group, and at least one of R ^{1 to} R ³ is an electron ring. represented by an aromatic ring having a donating group .R ¹ ~
R ³ may be the same or different. )

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The positive-working radiation-sensitive composition of the present invention contains a) a compound in which an alkali-soluble group is protected by an acid leaving group represented by the following general formula (1).

[0009]

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R ¹ is an aromatic ring having an electron donating group, and R ² and R ³ are each independently an alkyl group, a substituted alkyl group, a cycloalkyl group, an aromatic ring, or an aromatic ring having an electron donating group. .

The electron-donating group referred to here may be any one which has a higher tendency to donate electrons than hydrogen, such as an acyloxy group, an amino group, an alkyl group,
Examples include an alkoxy group. Among them, the electron donating group preferably used is an acyloxy group having 2 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Most preferred. Two or more electron donating groups may be present in one aromatic ring.

Specific examples of R ¹ include 4-acetyloxyphenyl, 4-acetyloxynaphthyl, 3-benzyloxyphenyl, 4-dimethylaminophenyl, 2-dimethylaminophenyl, and 4-aminonaphthyl. Group, p-tolyl group, m-tolyl group, o-tolyl group,
2,4-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4-t-butylphenyl group, 4-methylnaphthyl group, 4-methoxyphenyl group, 2-methoxyphenyl group, 3-ethoxyphenyl group, Examples thereof include a 4-t-butoxyphenyl group, a 4-phenoxyphenyl group, a 4-methoxynaphthyl group, a 3-isopropoxyphenyl group, a 4-methoxy-3-methylphenyl group, and a 3,5-dimethoxyphenyl group. Specific examples of R ² and R ³ include a methyl group, an ethyl group, a propyl group, a butyl group, a methoxymethyl group, an ethoxybutyl group, a hydroxyethyl group, a cyclohexyl group, a phenyl group, a tolyl group, a methoxyphenyl group, and Specific examples of R ¹ include the groups mentioned above. Introducing an electron-donating group into the aromatic ring on the tertiary carbon bonded to oxygen stabilizes the positive charge of the carbocation generated during deprotection, facilitating deprotection and greatly improving resist sensitivity. . Further, as the alkali-soluble group of a), a carboxyl group and a phenolic hydroxyl group are preferable.

The component (a) may be a low molecular weight compound or a polymer, but is preferably a polymer. More preferred as the component (a) is a polymer containing a structural unit represented by the following general formula (2) or (3).

[0014]

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R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, or a halogen. R ⁵ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, a halogen. Y
Is an acid leaving group represented by the general formula (1). In order to obtain such a polymer, for example, a monomer having a structure in which a carboxyl group of acrylic acid or methacrylic acid or a hydroxyl group of p-hydroxystyrene is protected by an acid leaving group represented by the general formula (1) is synthesized, It may be polymerized with azobisisobutyronitrile or the like.

Specific examples of the structural unit represented by the general formula (2) or (3) are shown below.

[0017]

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[0018]

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[0019]

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The polymer containing the structural unit represented by the general formula (2) or (3) may be a polymer containing only the structural unit represented by the general formula (2) or (3), A copolymer containing other monomer units may be used as long as the characteristics as a chemically amplified resist are not impaired. Other monomer structures include acrylic acid, methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, hydroxyethyl acrylate, isopropyl methacrylate, n- Butyl methacrylate, t-butyl methacrylate, methyl α-chloroacrylate, ethyl α-chloroacrylate, hydroxyethyl α-chloroacrylate, isopropyl α
-Chloroacrylate, n-butyl α-chloroacrylate, t-butyl α-chloroacrylate, methyl α-
Cyanoacrylate, ethyl α-cyanoacrylate, hydroxyethyl α-cyanoacrylate, isopropyl α-cyanoacrylate, n-butyl α-cyanoacrylate, styrene, p-hydroxystyrene, α-methylstyrene, α-methyl-p-hydroxy Styrene, maleic acid, maleic anhydride, crotonic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, acrylonitrile, methacrylonitrile, crotonitrile, maleinitrile, fumaronitrile, metaconitrile, citraconitrile, itaconitrile, acrylamide, methacrylic Amides, crotonamides, maleamides, fumaramides, mesaconamides, citraconamides, itaconamides, vinylanilines, vinylpyrrolidones, vinylimidazoles, etc. It can gel. When another monomer unit has an alkali-soluble group, the alkali-soluble group can be protected with an acid leaving group. Specific examples of acid leaving groups include methoxymethyl, methylthiomethyl, ethoxymethyl, ethylthiomethyl, methoxyethoxymethyl, benzyloxymethyl, benzylthiomethyl, phenacyl, bromophenacyl, methoxy Phenacyl group, methylthiophenacyl group,
α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, ethoxybenzyl group, methoxycarbonylmethyl group, ethoxy Carbonylmethyl group, n-propoxycarbonylmethyl group, isopropoxycarbonylmethyl group, n-butoxycarbonylmethyl group, t-butoxycarbonylmethyl group, propenyl group, 1-methoxyethyl group, 1-methylthioethyl group, 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-ben Ruchioechiru group, 1-cyclopropylethyl group, 1-phenylethyl, 1,1-diphenylethyl group, 1-methoxycarbonylethyl group,
1-ethoxycarbonylethyl group, 1-n-propoxycarbonylethyl group, 1-isopropoxycarbonylethyl group, 1-n-butoxycarbonylethyl group, 1-t
-Butoxycarbonylethyl group, isopropyl group, s-
Butyl group, t-butyl group, 1,1-dimethylbutyl group,
Trimethylsilyl, ethyldimethylsilyl, methyldiethylsilyl, triethylsilyl, isopropyldimethylsilyl, methyldiisopropylsilyl, triisopropylsilyl, t-butyldimethylsilyl, methyldi-t-butylsilyl, tri-t- Butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group, triphenylsilyl group, methoxycarbonyl group, ethoxycarbonyl group, isopropoxycarbonyl group, t-butoxycarbonyl group, acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl Group, valeryl group, pivaloyl group, isovaleryl group, lauryloyl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group, malonyl group, succinyl group,
Glutaryl, adipoyl, piperoyl, suberoyl, azelaoil, sebacoil, acryloyl, propyloyl, methacryloyl, crotonoyl, oleoyl, maleoyl, fumaroyl, mesaconoyl, benzoyl, phthaloyl, isophthaloyl Group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, furoyl group, tenoyl group, nicotinoyl group, isonicotinoyl group, p-toluenesulfonyl group, mesyl group, cyclopropyl group, cyclopentyl group , Cyclohexyl, cyclohexenyl, 4-methoxycyclohexyl, tetrahydropyranyl, tetrahydrofuranyl, tetrahydrothiopyranyl, tetrahydrothiofuranyl, 3-butane Mote tiger tetrahydropyranyl group, 4-
Examples thereof include a methoxytetrahydropyranyl group and a 4-methoxytetrahydrothiopyranyl group.

Further, the polymer containing a structural unit represented by the above general formula (2) or (3) preferably used in the present invention has the following ring structure in the main chain for improving dry etching resistance and the like. May be included.

[0022]

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Formula (2) preferably used in the present invention
Alternatively, the weight average molecular weight of the polymer containing the structural unit represented by (3) is 4 in terms of polystyrene measured by GPC.
000 to 1,000,000, preferably 5000 to 100
000, more preferably 5,000 to 50,000.

The aromatic ring having an electron donating group contained in the acid leaving group of the component a) is preferably a structure represented by the following general formula (4).

[0025]

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R ⁶ , R ⁸ and R ¹⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and at least one of them represents the above-mentioned alkyl group or alkoxy group. Represent. R ⁷ and R ⁹ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. By introducing an electron-donating group at the ortho or para position, higher sensitivity is exhibited.

The positive radiation-sensitive composition of the present invention comprises b)
Contains an acid generator that generates an acid upon irradiation with radiation. Thus, a pattern can be formed by the chemical amplification mechanism, and a high-sensitivity, high-resolution pattern can be obtained. The acid generator used herein may be any acid generator that increases the dissolution rate of the component (a) in an aqueous alkali solution by the generated acid, and includes an onium salt, a halogen-containing compound, a diazoketone compound, Examples thereof include a diazomethane compound, a sulfone compound, a sulfonate compound, and a sulfonimide compound.

Specific examples of the onium salts include diazonium salts, ammonium salts, iodonium salts, sulfonium salts, phosphonium salts, oxonium salts and the like. Preferred onium salts include diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate And the like.

Specific examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound. Preferred halogen-containing compounds include 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, and 2-naphthyl-4,6. -Bis (trichloromethyl)
-S-triazine and the like.

Specific examples of the diazoketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, and a diazonaphthoquinone compound. Preferred diazoketone compounds are 1,2-naphthoquinonediazido-4-sulfonic acid and 2,2,3,4,4 '
Esters with tetrahydroxybenzophenone, 1,
2-naphthoquinonediazide-4-sulfonic acid and 1,1,
Examples thereof include esters with 1-tris (4-hydroxyphenyl) ethane.

Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane,
Bis (phenylsulfonyl) diazomethane, bis (p-
Tolylsulfonyl) diazomethane, bis (2,4-xylylsulfonyl) diazomethane, bis (p-chlorophenylsulfonyl) diazomethane, methylsulfonyl-p
-Toluenesulfonyldiazomethane, cyclohexylsulfonyl (1,1-dimethylethylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, phenylsulfonyl (benzoyl) diazomethane and the like.

Specific examples of the sulfone compound include β
-Ketosulfone compounds, β-sulfonylsulfone compounds and the like. Preferred compounds include 4-trisphenacylsulfone, mesitylphenacylsulfone,
Bis (phenylsulfonyl) methane and the like can be mentioned.

Examples of the sulfonic acid ester compound include:
Examples thereof include alkylsulfonic acid esters, haloalkylsulfonic acid esters, arylsulfonic acid esters, and iminosulfonates. Specific examples of the sulfonic acid compound include benzoin tosylate, pyrogallol trimesylate, and nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate.

Specific examples of the 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) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] Heptane-5,6
-Oxy-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthyldicarboximide, N- (camphorsulfonyloxy) succinimide, N- (camphorsulfonyloxy) phthalimide, N- (camphorsulfonyloxy) Diphenylmaleimide, N- (camphorsulfonyloxy)
Bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-
Ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N
-(Camphorsulfonyloxy) naphthyldicarboximide, N- (4-methylphenylsulfonyloxy) succinimide, N- (4-methylphenylsulfonyloxy) phthalimide, N- (4-methylphenylsulfonyloxy) diphenylmaleimide, N- (4-
Methylphenylsulfonyloxy) bicyclo [2.2.
1] Hept-5-ene-2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) -7
-Oxabicyclo [2.2.1] hept-5-ene-
2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide,
N- (4-methylphenylsulfonyloxy) naphthyldicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) succinimide, N- (2
-Trifluoromethylphenylsulfonyloxy) phthalimide, N- (2-trifluoromethylphenylsulfonyloxy) diphenylmaleimide, N- (2-trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene -2,3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) -7-oxabicyclo [2.2.1]
Hept-5-ene-2,3-dicarboximide, N
-(2-trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) naphthyldicarboxyl Imide, N- (4-fluorophenylsulfonyloxy) succinimide, N- (2-fluorophenylsulfonyloxy) phthalimide, N- (4-fluorophenylsulfonyloxy) diphenylmaleimide, N-
(4-Fluorophenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) -7-oxabicyclo [2.2. 1] Hept-5
-Ene-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.2.
1] Heptane-5,6-oxy-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) naphthyldicarboximide and the like.

These acid generators can be used alone or in combination of two or more. The amount of the acid generator to be added is generally 0.01 to 50% by weight, more preferably 0.1 to 10% by weight, based on the polymer. 0.01% by weight
If the amount is less than 50%, the pattern cannot be formed.
If the amount is larger than the above, affinity with the developing solution is lowered, and poor development occurs.

If necessary, additives such as a surfactant, a sensitizer, a stabilizer, an antifoaming agent and an acid diffusion inhibitor can be added to the positive-type radiation-sensitive composition of the present invention.

The positive radiation-sensitive composition of the present invention can be obtained by dissolving the above components in a solvent. The amount of the solvent used is not particularly limited, but is adjusted so that the solid content is 5 to 35% by weight. Preferred solvents used are ethyl acetate, butyl acetate, amyl acetate, ethyl propionate, methyl butyrate, methyl benzoate, methyl lactate, ethyl lactate, ethyl pyruvate, methyl β-isobutyrate, methyl 3-methoxypropionate, -Ethyl ethoxypropionate, esters such as γ-butyrolactone, cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve esters such as methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol Propylene glycol esters such as monoethyl ether acetate, 1,2-dimethoxyethane, 1,2
-Diethoxyethane, tetrahydrofuran, ethers such as anisole, methyl ethyl ketone, methyl isobutyl ketone, methyl-n-amyl ketone, cyclohexanone, ketones such as isophorone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, sulfolane and the like Solvents selected from aprotic polar solvents, or composite solvents thereof.

The positive-working radiation-sensitive composition of the present invention is applied on a substrate to be processed, dried, and usually used as a thin film having a thickness of 0.2 μm to 2 μm. An electron beam, X
A fine pattern can be obtained by pattern exposure using radiation such as a line or vacuum ultraviolet ray, and baking and developing after exposure. In particular, the effect becomes more remarkable when an electron beam is used.

The development of the radiation-sensitive composition of the present invention can be carried out using a known developer. Examples include inorganic alkalis such as hydroxides, carbonates, phosphates, silicates and borates of alkali metals, amines such as 2-diethylaminoethanol, monoethanolamine and diethanolamine, and tetramethylammonium hydroxide. And aqueous solutions containing one or more quaternary ammoniums such as choline and choline.

[0040]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The weight average molecular weight in this example is a GPC (gel permeation chromatography) measurement value in terms of polystyrene. For GPC measurement, GPC columns “KF-804” and “KF-8” manufactured by Showa Denko K.K.
03 "and" KF-802 "are connected and used, and tetrahydrofuran is used as a mobile phase at a flow rate of 0.8 ml / min.
And The sample concentration was 0.2% by weight and the sample injection amount was 0.1
0 ml. A differential refractometer was used as a detector.

EXAMPLE 1 A 60:40 (molar ratio) mixture of 2- (4-methoxyphenyl) -2-propyl methacrylate and itaconic anhydride was started with azobisisobutyronitrile in 1,4-dioxane. Polymerized at 70 ° C as an agent, the following chemical formula (5)
(Weight average molecular weight 9700) was obtained. 3 g of this polymer, triphenylsulfonium triflate 300
mg in methyl cellosolve acetate, 0.2 μl
The mixture was filtered through a filter of m to obtain a resist composition.

The obtained resist composition was spin-coated on a HMDS-treated silicon wafer, and then heated at 100 ° C.
For 2 minutes to obtain a resist film having a thickness of 0.5 μm.
An acceleration voltage of 2 was applied to this resist film using an electron beam exposure apparatus.
The pattern was irradiated with an electron beam at 0 kV, heated at 90 ° C. for 2 minutes, and then developed with a 2.38% tetramethylammonium hydroxide aqueous solution (ELM-D manufactured by Mitsubishi Gas Chemical Co., Ltd.) for 1 minute. At an exposure of 1.6 μC / cm ^2, the
A pattern of 19 μm was obtained.

[0043]

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Example 2 A resist film was obtained in the same manner as in Example 1 except that a copolymer represented by the following chemical formula (6) (weight average molecular weight: 19000) was used instead of the copolymer used in Example 1. Irradiation was carried out for development. At an exposure of 1.9 μC / cm ² , a pattern of 0.20 μm was obtained.

[0045]

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Example 3 A resist film was obtained in the same manner as in Example 1 except that a polymer (weight average molecular weight: 11,000) represented by the following chemical formula (7) was used instead of the copolymer used in Example 1. And developed. At an exposure of 1.4 μC / cm ² ,
A pattern of 0.20 μm was obtained.

[0047]

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Example 4 A resist film was obtained in the same manner as in Example 1 except that a copolymer (weight average molecular weight: 4500) represented by the following chemical formula (8) was used instead of the copolymer used in Example 1. Irradiation was carried out for development. A pattern of 0.24 μm was obtained at an exposure amount of 3.0 μC / cm ² .

[0049]

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Example 5 A resist film was obtained in the same manner as in Example 1 except that a copolymer (weight average molecular weight: 56,000) represented by the following chemical formula (9) was used instead of the copolymer used in Example 1. Irradiation was carried out for development. A pattern of 0.23 μm was obtained with an exposure of 3.5 μC / cm ² .

[0051]

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Example 6 Instead of the copolymer used in Example 1, the following chemical formula (1) was used.
A resist film was obtained in the same manner as in Example 1 except that the copolymer (0) (weight average molecular weight 18,000) was used, and the film was developed by irradiation with an electron beam. A pattern of 0.21 μm was obtained at an exposure amount of 2.4 μC / cm ² .

[0053]

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Example 7 Instead of the copolymer used in Example 1, the following chemical formula (1) was used.
A resist film was obtained in the same manner as in Example 1 except that the copolymer (1) (weight average molecular weight: 25,000) was used, and the resist film was irradiated with an electron beam and developed. A pattern of 0.20 μm was obtained at an exposure of 1.7 μC / cm ² .

[0055]

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Example 8 The same experiment as in Example 1 was performed except that an i-line stepper was used as an exposure apparatus. 0.1 at an exposure of 29 mJ / cm ² .
A pattern of 31 μm was obtained.

Comparative Example 1 Instead of the copolymer used in Example 1, poly (t-butyl-α-chloroacrylate) (weight average molecular weight 210
A resist film was obtained in the same manner as in Example 1 except that (00) was used, and the resist film was irradiated with an electron beam and developed. 6.2 μC / c
A pattern of 0.33 μm was obtained with an exposure amount of m ^{2, and} the characteristics were not sufficient in terms of sensitivity and resolution.

Comparative Example 2 Instead of the copolymer used in Example 1, the following chemical formula (1)
A resist film was obtained and evaluated in the same manner as in Example 1 except that the copolymer (2) (weight average molecular weight 12,000) was used.

[0059]

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0.25 μm at an exposure of 5.8 μC / cm ²
m pattern was obtained, and both the sensitivity and the resolution were not sufficient characteristics.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

[0064]

As described above, the positive-type radiation-sensitive composition of the present invention has high resolution by using a compound having a specific protective group and an acid generator which generates an acid upon irradiation with radiation. And it became possible to obtain a highly sensitive composition.

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[Procedure amendment]

[Submission date] November 8, 2001 (2001.11.
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

R ^{1 to} R ³ are an alkyl group, a substituted alkyl group,
Aroma with cycloalkyl group, aromatic ring, electron donating group
Represented by any of rings, at least one of R ^{1 to} R ³
Is represented by an aromatic ring having an electron donating group. R ^{1 to} R ³ are
Each may be the same or different.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

Specific examples of R ^{1 to} R ³ include a 4-acetyloxyphenyl group, a 4-acetyloxynaphthyl group,
-Benzyloxyphenyl, 4-dimethylaminophenyl, 2-dimethylaminophenyl, 4-aminonaphthyl, p-tolyl, m-tolyl, o-tolyl, 2,4-dimethylphenyl, 2, , 4,6-trimethylphenyl group, 4-t-butylphenyl group, 4-methylnaphthyl group, 4-methoxyphenyl group, 2-methoxyphenyl group, 3-ethoxyphenyl group, 4-t-butoxyphenyl group, 4 - phenoxyphenyl group, 4-methoxynaphthyl group, 3-isopropoxyphenyl group, 4-methoxy-3-methylphenyl group, 3,5-dimethoxyphenyl group, ethyl group, propyl group, butyl group, methoxy methyl group, an ethoxy butyl group, a hydroxyethyl group, a cyclohexyl group, and etc. phenyl group. Introducing an electron-donating group into the aromatic ring on the tertiary carbon bonded to oxygen stabilizes the positive charge of the carbocation generated during deprotection, facilitating deprotection and greatly improving resist sensitivity. . Further, as the alkali-soluble group of a), a carboxyl group and a phenolic hydroxyl group are preferable.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08L 101/02 C08L 101/02 H01L 21/027 H01L 21/30 502R F-term (Reference) 2H025 AA01 AA02 AB03 AB16 AC08 AD03 BE00 BE10 CB14 CB17 CB41 CB43 FA10 4J002 BC121 BG041 BG051 BG071 BG111 EB106 EN136 EQ016 EV216 EV266 EV296 EW176 FD206 GP03 4J100 AB07P AL08P AL26P AM05P BA02P BA04P BA05P BA06P BA10P BA31P BC31

Claims (10)

[Claims] 1. A positive electrode comprising: a) a compound in which an alkali-soluble group is protected by an acid leaving group represented by the general formula (1); and b) an acid generator that generates an acid upon irradiation with radiation. Type radiation-sensitive composition. Embedded image (R ^{1 to} R ³ are represented by any of an alkyl group, a substituted alkyl group, a cycloalkyl group, an aromatic ring and an aromatic ring having an electron donating group, and at least one of R ^{1 to} R ³ is an electron donating group And R ^{1 to} R ³ may be the same or different.) 2. The positive radiation-sensitive composition according to claim 1, wherein the alkali-soluble group of a) is a carboxyl group. 3. The positive radiation-sensitive composition according to claim 1, wherein the alkali-soluble group in a) is a phenolic hydroxyl group. 4. A positive radiation-sensitive composition according to claim 1, wherein the compound of a) is a polymer. 5. The positive radiation-sensitive composition according to claim 1, wherein a) is a polymer containing a structural unit represented by the general formula (2). Embedded image (R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, or a halogen. Y is an acid leaving group represented by the general formula (1).) 6. The positive radiation-sensitive composition according to claim 1, wherein a) is a polymer containing a structural unit represented by the general formula (3). Embedded image (R ⁵ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, or a halogen. Y is an acid leaving group represented by the general formula (1).) 7. The method according to claim 1, wherein the aromatic ring having an electron donating group has a structure represented by the general formula (4).
The positive-type radiation-sensitive composition as described in the above. Embedded image (R ⁶ , R ⁸ and R ¹⁰ each independently represent a hydrogen atom,
Represents an alkyl group having 4 to 4 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, at least one of which represents the alkyl group or the alkoxy group. R ⁷ and R ⁹ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. ) 8. The positive radiation-sensitive composition according to claim 1, wherein the electron donating group is an alkoxy group having 1 to 6 carbon atoms. 9. A method for producing a pattern wherein the positive-type radiation-sensitive composition according to claim 1 is applied onto a substrate to be processed, dried, exposed and developed. 10. The method according to claim 9, wherein the exposure is performed by an electron beam.