JP2001166479A - Positive type radiation sensitive composition and method for producing resist pattern using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high sensitivity positive type radiation sensitive composition having such a resolution as to attain sub-quarter micron patterning. SOLUTION: The positive type radiation sensitive composition contains (A) a polymer containing structural units of formulae 1 and 2 (where R1 is H, alkyl, cycloalkyl, arylalkyl, alkoxyalkyl, haloalkyl, hydroxyalkyl, silyl, silylalkyl, siloxy or siloxyalkyl; R2 is an organic group of formula 3 or 4; and X is a 1-4C alkyl, halogen or cyano) and (B) an acid generating agent which generates an acid when irradiated. A method for producing a 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. Furthermore, it is difficult to perform such fine processing by lithography using a relatively long-wavelength light source as in the related art.
Lithography using X-rays and electron beams is being studied, and resists corresponding to such light sources are required.

In recent years, in order to cope with such a light source, a chemically amplified resist has been actively studied as a known resist material having high sensitivity and high resolution characteristics. Chemically amplified resists have a mechanism in which an acid is generated in the exposed area by the action of a photoacid generator, and the solubility of the exposed area is changed by the catalytic action of the acid. A resin in which a group is protected by an acid-decomposable group such as a t-butyl ester group or a t-butoxycarbonyl group is used.

[0004]

However, the resist characteristics such as resolution and sensitivity and dry etching resistance are in conflict with each other, and the sensitivity is not sufficient to obtain a resolution for performing sub-quarter micron pattern processing. There were drawbacks such as. Also, particularly when performing electron beam exposure, low sensitivity was a major problem.

[0005]

The present invention relates to (A) a polymer containing structural units represented by the following general formulas (1) and (2) and (B) an acid capable of generating an acid upon irradiation with radiation. A positive radiation-sensitive composition containing a generator and a method for producing a resist pattern using the composition.

[0006]

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[0007]

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[0008] (R ¹ is .R ² representing a hydrogen atom, an alkyl group, a cycloalkyl group, an arylalkyl group, an alkoxyalkyl group, a haloalkyl group, a hydroxyalkyl group, a silyl group, a silyl group, a siloxy group, a siloxy group Is an organic group represented by the following chemical formula (3) or (4), and X represents an alkyl group having 1 to 4 carbon atoms, a halogen atom, and a cyano group.

[0009]

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[0010]

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(E represents an acid leaving group.)

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below.

The positive radiation-sensitive composition of the present invention comprises:
(A) It contains a polymer containing structural units represented by the general formulas (1) and (2).

[0014]

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[0015]

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Here, R ¹ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an arylalkyl group, an alkoxyalkyl group, a haloalkyl group, a hydroxyalkyl group, a silyl group, a silylalkyl group, a siloxy group, or a siloxyalkyl group. X represents an alkyl group having 1 to 4 carbon atoms, a halogen atom, or a cyano group.

The polymer (A) has a sulfone structure (-
SO _2- ). By introducing this structure, the main chain is easily cut at the time of exposure. As a result, the molecular weight of the polymer is reduced in the exposed area, and a high-contrast image is obtained. Such a main chain scission reaction occurs particularly easily when a high energy source such as an electron beam or X-ray is used. Further, when X is an alkyl group having 1 to 4 carbon atoms, a halogen atom, or a cyano group, the main chain is more easily broken than in the case of other substituents.

R ^{2 in the} general formula (2) is represented by the following chemical formula (3)
Or an organic group represented by (4), wherein E represents an acid leaving group.

[0019]

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[0020]

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The acid leaving group mentioned here may be any group as long as it can be eliminated by the acid generated from the acid generator (B) which generates an acid upon irradiation with radiation. Specific examples of the acid leaving group include a methoxymethyl group, a methylthiomethyl group, an ethoxymethyl group, an ethylthiomethyl group,
Methoxyethoxymethyl group, benzyloxymethyl group,
Benzylthiomethyl group, phenacyl group, bromophenacyl group, methoxyphenacyl group, methylthiophenacyl group, α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, promobenzyl group, nitro Benzyl, methoxybenzyl, methylthiobenzyl, ethoxybenzyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, n-propoxycarbonylmethyl, isopropoxycarbonylmethyl, n-butoxycarbonylmethyl, t-butoxycarbonylmethyl Group, propenyl group, 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1-diethoxyethyl group, 1 -Phenoxy Butyl, 1-phenylthioethyl, 1,1-diphenoxyethyl, 1-benzyloxyethyl, 1-benzylthioethyl, 1-cyclopropylethyl, 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-
Methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl group, 3-tetrahydrothiophene-
Examples thereof include 1,1-dioxide.

From the viewpoint of dry etching resistance, the structural unit represented by the general formula (2) preferably has at least one cyclic organic group and / or silyl group, and the cyclic organic group is an aromatic ring. Is more preferable. When an aromatic ring is introduced into a polymer, it is possible to impart higher dry etching resistance than an alicyclic skeleton, and it is generally more cost-effective than an alicyclic skeleton. When exposure is performed with ultraviolet light such as KrF or ArF, the pattern shape may be deteriorated due to light absorption of an aromatic ring. However, exposure with electron beam, X-ray, or the like can obtain a good pattern without such a problem. Can be.

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

[0024]

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[0025]

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It is to be noted that a preferable composition ratio of the structural units represented by the general formulas (1) and (2) is m in the general formula (1) and n in the general formula (2). Then 0.05
<M <0.5, 0.05 <n <0.95, more preferably 0.1 <m <0.5, 0.1 <n <0.9, and still more preferably 0.1 <m <0.5, 0.3 <n <0.
9

The polymer (A) used in the present invention may be a polymer containing only the structural units represented by the general formulas (1) and (2). The copolymer containing other monomer units may be used as long as the above is not impaired. Other monomer structures include acrylic acid, α-chloroacrylic acid, α-bromoacrylic acid,
α-cyanoacrylic acid, methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, methyl α-chloroacrylate, ethyl α-chloroacrylate, isopropyl α-chloroacrylate, n-butyl α-chloroacrylate, t-butyl α-chloroacrylate, phenyl α-chloroacrylate, methyl α-cyanocry Rate, ethyl α-cyanoacrylate, isopropyl α-cyanoacrylate, n-butyl α-cyanoacrylate, styrene, p- Hydroxystyrene, α
-Methylstyrene, α-methyl-p-hydroxystyrene, maleic acid, maleic anhydride, crotonic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, acrylonitrile, methacrylonitrile, crotonnitrile, maleinitrile, fumaronitrile, metaconyl Nitrile,
Examples thereof include citraconitrile, itaconitrile, acrylamide, methacrylamide, crotonamide, maleamide, fumaramide, mesaconamide, citraconamide, itaconamide, vinylaniline, vinylpyrrolidone, and vinylimidazole.

Among these structures, it is more preferable to include a structure represented by the following general formula (5) in terms of sensitivity.
By containing the quaternary carbon having an α hydrogen in the main chain, the main chain is more easily cut by radiation, and the sensitivity is improved.

[0029]

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R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, an alkoxyalkyl group, a haloalkyl group, a hydroxyalkyl group,
Represents an alkoxyaryl group, a haloaryl group, a hydroxyaryl group, a silylalkyl group, a silylaryl group, a silylarylalkyl group, a siloxyalkyl group, or a siloxyaryl group. R ⁵ is an alkyl group, an aryl group, an arylalkyl group, an alkoxyalkyl group, a haloalkyl group, a hydroxyalkyl group, an alkoxyaryl group,
Haloaryl group, hydroxyaryl group, silylalkyl group, silylaryl group, silylarylalkyl group,
Acyloxyalkyl group, a siloxane shear aryl group, R ⁶
Represents an alkyl group, an arylalkyl group, an alkoxyalkyl group, a haloalkyl group, a hydroxyalkyl group, a silylalkyl group, a silylarylalkyl group, or a siloxyalkyl group. R ³ and R ⁵ may be closed.

The general formula (5) contained in the polymer A
The molar ratio p of the structural unit represented by is 0.05 <p <0.
8, more preferably 0.1 <p <0.5.

Specific examples of the structural unit represented by the general formula (5) are shown below.

[0033]

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Further, the following monomer units having an alicyclic skeleton in the main chain and containing an acid-decomposable group may be contained.

[0035]

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The weight average molecular weight of the polymer (A) used in the present invention is 50 in terms of polystyrene measured by GPC.
00 to 1500000, preferably 5000 to 1000
000, more preferably 6,000 to 100,000, most preferably 6,000 to 50,000.

The positive radiation-sensitive composition of the present invention contains an acid generator which generates an acid upon irradiation with radiation. This enables a pattern to be formed by a chemical amplification mechanism in addition to the main chain cleavage, and a high-sensitivity, high-resolution pattern can be obtained. The acid generator used here may be any as long as it can decompose the acid-decomposable organic group of the general formula (1) by the generated acid. Onium salts, halogen-containing compounds, diazoketone compounds, diazomethane compounds, sulfone compounds,
Sulfonate compounds, sulfonimide compounds and the like can be mentioned as examples.

Specific examples of 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- (campanylsulfonyloxy) succinimide, N- (campanylsulfonyloxy)
Phthalimide, N- (campanylsulfonyloxy)
Diphenylmaleimide, N- (campanylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-
2,3-dicarboximide, N- (campanylsulfonyloxy) -7-oxabicyclo [2.2.1]
Hept-5-ene-2,3-dicarboximide, N
-(Campanylsulfonyloxy) bicyclo [2.
2.1] Heptane-5,6-oxy-2,3-dicarboximide, N- (campanylsulfonyloxy)
Naphthyl dicarboximide, 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)
Naphthyl dicarboximide, 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-
Examples thereof include 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.

The positive radiation-sensitive composition of the present invention may contain a dissolution inhibitor. The dissolution inhibitor has a group that is decomposed by the action of an acid and becomes alkali-soluble. The dissolution inhibitor, when added to the composition, has the effect of reducing the rate of alkali dissolution of the composition until it is affected by an acid, and the alkali-soluble group is decomposed by the action of an acid, thereby reducing the composition. A compound that has the effect of increasing the alkali dissolution rate of a substance. As the dissolution inhibitor, for example, a compound containing an acidic functional group such as a phenolic hydroxyl group, a carboxyl group, and a sulfoxy group, in which a hydrogen atom of the acidic functional group is substituted with an acid leaving group, can be used. Examples of the compound having an acidic functional group used herein include hydroquinone, catechol, bisphenol A, hydroxyphenylacetic acid, 4-hydroxybenzenesulfonic acid, and the like. Examples of the acid leaving group include methoxymethyl, methylthiomethyl, ethoxymethyl, ethylthiomethyl, methoxyethoxymethyl, benzyloxymethyl, benzylthiomethyl, phenacyl, bromophenacyl, methoxyphenacyl, methylthio Phenacyl 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-
Methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl group, 3-terolahydrothiophene-
1,1-dioxide and the like can be mentioned.

As the dissolution inhibitor used in the present invention, a high molecular compound can also be used. As the polymer dissolution inhibitor, those in which a hydrogen atom of a hydroxy group or a carboxyl group of a polymer having a hydroxy group or a carboxyl group is substituted by the above-mentioned acid leaving group are used. Specific examples of the polymer having a hydroxyl group or a carboxyl group include hydroxystyrene, α-methylhydroxystyrene, α-chlorohydroxystyrene, vinylbenzoic acid, carboxymethylstyrene, carboxymethoxystyrene, acrylic acid, methacrylic acid, and croton. Examples include at least one polymer of a monomer having a polymerizable double bond such as an acid, maleic acid, itaconic acid, and cinnamic acid, and a condensation polymer represented by a novolak resin. Specific examples of the acid leaving group include the aforementioned acid leaving groups.

The dissolution inhibitor is used in an amount of 0 to 150 parts by weight, preferably 5 to 100 parts by weight, more preferably 5 to 100 parts by weight based on 100 parts by weight of the polymer containing the structural unit represented by the general formula (1).
50 parts by weight.

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 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-type 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. The thin film is subjected to pattern exposure using radiation such as ultraviolet rays, far ultraviolet rays, electron beams, X-rays, etc., followed by baking and development after exposure to obtain a fine pattern. In particular, the effect is large in the case of pattern exposure using an electron beam or X-ray, and the effect is more remarkable in the case of using an electron beam.

The radiation-sensitive composition of the present invention can be developed 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.

[0053]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Note that the measurement of the weight average molecular weight in this example was performed using G
PC (gel permeation chromatography) based on polystyrene. In addition, the copolymerization ratio of each structural unit is determined by an NMR spectrum (measurement apparatus: JNM).
-EX-270 (JEOL) Determination solvent: determined by dimethyl sulfoxide d6) and elemental analysis.

Example 1 Using azobisisobutyronitrile as an initiator, sulfone and α-methyl-p- (tetrahydropyranyloxy) styrene were polymerized in toluene at 70 ° C., and the chemical formula (6) shown below was obtained. ) Was obtained.

[0055]

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The weight average molecular weight of this polymer was 12,000.
Met. 3 g of this polymer and 150 mg of triphenylsulfonium triflate were dissolved in propylene glycol monomethyl ether acetate, and filtered through a 0.1 μm filter to obtain a resist composition. After spin-coating the obtained resist composition on a silicon wafer, 1
Heating was performed at 00 ° C. for 2 minutes to obtain a 0.5 μm-thick resist film. The resist film is irradiated with an electron beam in a pattern at an acceleration voltage of 20 kV using an electron beam exposure apparatus.
After heating for 2 minutes, development was performed with an aqueous solution of tetramethylammonium hydroxide. At an exposure of 4.8 μC / cm ² , a pattern of 0.24 μm was obtained.

Example 2 A polymer represented by the following chemical formula (7) (weight average molecular weight: 14) was obtained in the same manner as in Example 1 except that sulfone and 2-phenyl-2-propyl α-chloroacrylate were used as raw materials.
000) and 150 mg of triphenylsulfonium triflate were dissolved in propylene glycol monomethyl ether acetate, and filtered through a 0.1 μm filter to obtain a resist composition.

[0058]

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Example 1 Using the Resist Composition Obtained
The same experiment was performed. A pattern of 0.23 μm was obtained at an exposure amount of 4.3 μC / cm ² .

Example 3 A polymer of the following chemical formula (8) (weight average molecular weight 1400) obtained in the same manner as in Example 1 except that sulfone and α-methyl-4-trimethylsiloxystyrene were used as raw materials
0) 3 g, triphenylsulfonium triflate 15
0 mg was dissolved in propylene glycol monomethyl ether acetate and filtered through a 0.1 μm filter to obtain a resist composition.

[0061]

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Example 1 Using the Resist Composition Obtained
The same experiment was performed. A pattern of 0.24 μm was obtained at an exposure amount of 4.5 μC / cm ² .

Example 4 Sulfone, 2-methylnorbornene and 2
3 g of a polymer of the following chemical formula (9) (weight average molecular weight: 19000) and 150 mg of triphenylsulfonium triflate obtained in the same manner as in Example 1 except that -ethoxyethoxy-α-methylstyrene was used, was converted to propylene glycol monomethyl ether acetate. Dissolve, 0.1 μm
To obtain a resist composition.

[0064]

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Example 1 Using the Resist Composition Obtained
The same experiment was performed. A pattern of 0.23 μm was obtained at an exposure of 3.7 μC / cm ² .

Example 5 The same experiment as in Example 1 was performed except that an i-line stepper was used as an exposure apparatus. 0.3 at an exposure of 36 mJ / cm ² .
A pattern of 36 μm was obtained.

Comparative Example 1 Instead of the polymer used in Example 1, the following chemical formula (10)
The same experiment as in Example 1 was performed except that the polymer (weight average molecular weight 15,000) was used.

[0068]

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0.33 μm at an exposure of 6.8 μC / cm ²
m patterns were obtained, and the characteristics were not sufficient in terms of sensitivity and resolution.

Comparative Example 2 The same experiment as in Comparative Example 1 was performed except that an i-line stepper was used as an exposure apparatus. 0.1 at an exposure of 50 mJ / cm ² .
A pattern of 48 μm was obtained, and the characteristics were not sufficient in terms of sensitivity and resolution.

Comparative Example 3 The following chemical formula (11) was used in place of the polymer used in Example 1.
The same experiment as in Example 1 was conducted except that the polymer (weight average molecular weight 14,000) was used.

[0072]

Embedded image

0.35 μm at an exposure of 5.7 μC / cm ²
m patterns were obtained, and the characteristics were not sufficient in terms of sensitivity and resolution.

Comparative Example 4 The following chemical formula (12) was used instead of the polymer used in Example 1.
The same experiment as in Example 1 was conducted except that the polymer (weight average molecular weight: 60000) was used.

[0075]

Embedded image

0.31 μm at an exposure of 8.2 μC / cm ²
m patterns were obtained, and the characteristics were not sufficient in terms of sensitivity and resolution.

[0077]

[Table 1]

[0078]

[Table 2]

[0079]

As described above, the positive-type radiation-sensitive composition of the present invention comprises a polymer containing a sulfone structure and a specific structure having an acid-decomposable group, and an acid capable of generating an acid upon irradiation with radiation. By using a positive-type radiation-sensitive composition containing a generator, a composition having high resolution and high sensitivity can be obtained.

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[Procedure amendment]

[Submission date] December 1, 2000 (200.12.
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0025

[Correction method] Change

[Correction contents]

[0025]

Embedded image

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

The polymer (A) used in the present invention may be a polymer containing only the structural units represented by the general formulas (1) and (2). The copolymer containing other monomer units may be used as long as the above is not impaired. Other monomer structures include acrylic acid, α-chloroacrylic acid, α-bromoacrylic acid,
α-cyanoacrylic acid, methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, methyl α-chloroacrylate, ethyl α-chloroacrylate, isopropyl α-chloroacrylate, n-butyl α-chloroacrylate, t-butyl α-chloroacrylate, phenyl α-chloroacrylate, methyl α-cyanocry Rate, ethyl α-cyanoacrylate, isopropyl α-cyanoacrylate, n-butyl α-cyanoacrylate, styrene, p- Hydroxystyrene, α
-Methylstyrene, α-methyl-p-hydroxystyrene, maleic acid, maleic anhydride, crotonic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, itacone
Acid anhydride, acrylonitrile, methacrylonitrile, crotonitrile, maleinitrile, fumaronitrile,
Examples include metaconnitrile, citraconitrile, itaconitrile, acrylamide, methacrylamide, crotonamide, maleamide, fumaramido, mesaconamide, citraconamide, itaconamide, vinylaniline, vinylpyrrolidone, and vinylimidazole.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA01 AA02 AA09 AB08 AB16 AC06 AD03 BE00 BE10 BF23 BG00 CB08 CB14 CB17 CB19 CB34 CB41 2H096 AA24 AA25 BA11 EA06 GA08 4J030 BA09 BA47 BB23 BB24 BB25 BC02 BC02 BC02

Claims (6)

[Claims] 1. A polymer containing (A) a polymer containing structural units represented by the following general formulas (1) and (2) and (B) an acid generator that generates an acid upon irradiation with radiation. Positive radiation-sensitive composition. Embedded image Embedded image (R ¹ is a hydrogen atom, an alkyl group, a cycloalkyl group, an arylalkyl group, an alkoxyalkyl group, a haloalkyl group, a hydroxyalkyl group, a silyl group, a silyl group, siloxy group, .R ² representing the acyloxyalkyl group is represented by the following formula (3) or an organic group represented by (4), wherein X represents an alkyl group having 1 to 4 carbon atoms, a halogen atom, and a cyano group. Embedded image (E represents an acid leaving group.) 2. The positive radiation-sensitive composition according to claim 1, wherein the structural unit represented by the general formula (2) has at least one cyclic organic group and / or silyl group. 3. The positive radiation-sensitive composition according to claim 1, wherein the structural unit represented by the general formula (2) has at least one aromatic ring. 4. The polymer of (A) is a polymer containing structural units represented by the general formulas (1), (2) and (5). 3. The positive-type radiation-sensitive composition according to item 1. Embedded image (R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, an alkoxyalkyl group, a haloalkyl group, a hydroxyalkyl group, an alkoxyaryl group, a haloaryl group, a hydroxyaryl group, a silylalkyl group, a silyl R ⁵ represents an aryl group, a silylarylalkyl group, a siloxyalkyl group, or a siloxyaryl group, and R ⁵ represents an alkyl group, an aryl group, an arylalkyl group, an alkoxyalkyl group, a haloalkyl group,
Hydroxyalkyl group, alkoxyaryl group, haloaryl group, hydroxyaryl group, silylalkyl group,
Represents a silylaryl group, a silylarylalkyl group, a siloxyalkyl group, a siloxyaryl group, and R ⁶ represents an alkyl group, an arylalkyl group, an alkoxyalkyl group,
Represents a haloalkyl group, a hydroxyalkyl group, a silylalkyl group, a silylarylalkyl group, or a siloxyalkyl group. R ³ and R ⁵ may be closed. ) 5. 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. 6. The method according to claim 5, wherein the exposure is performed by an electron beam.