JP2000298346A - Positive radiation-sensitive composition and manufacture of resist pattern by using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the positive radiation-sensitive composition having a resolution capable of forming a subquarter micron pattern composition and high in sensitivity. SOLUTION: This positive radiation-sensitive composition is characterized by containing a polymer having structural units each represented by formula I containing A to be decomposed by action of an acid and solubilized in an alkali and formula II and an acid generator to be decomposed by action of an acid and solubilized in an alkali, and the method for manufacturing the resist pattern by using this composition is provided, too. In formulae I and II, X is a halogen atom or a cyano group, and Y is a 1-4C alkyl group or same as X; A is an organic group having >=1 silyl group; and G is a 1-10C haloalkyl or haloaryl or haloaralkyl group.

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. 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 exhibiting relatively good resist performance have protected an alkali-affinity group in an alkali-soluble resin with a t-butyl ester group or a t-butoxycarbonyl group as a resin component. Resin (Tokuhei 2-276)
No. 60), a resin similarly protected by a silyl group (Japanese Patent Publication No. 3-44290), a resin similarly protected by a ketal group (JP-A-7-140666), and a resin similarly protected by an acetal group ( JP-A-2-161436 and JP-A-5-249682), and resists using a resin containing a (meth) acrylic acid component (Japanese Patent Publication No. 4-39665) are known. JP-A-6
Japanese Patent No. 289608 discloses a chemically amplified resist using a tertiary alkyl ester of an acrylic acid derivative.

As a resist material having a high dry etch resistance by introducing a silyl group into a polymer side chain, a polymer obtained by introducing a silyl group into an α-chloroacrylate (Japanese Patent Publication No. 6-82215) ) And the like are known.

[0005]

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. Further, since the above-mentioned silyl group-containing resist is a non-chemically amplified type, the sensitivity and the resolution are not sufficient, and it is necessary to perform development with an organic solvent which is difficult to process.

[0006]

That is, the present invention comprises a polymer containing a structural unit represented by the following general formulas (1) and (2) and an acid generator which generates an acid upon irradiation with radiation. A positive-type radiation-sensitive composition, wherein A in the polymer is an organic group that is decomposed by the action of an acid to generate an alkali-soluble group, and a method for producing a resist pattern using the same.

[0007]

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[0008]

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(X is a halogen atom or a cyano group; Y is an alkyl group having 1 to 4 carbon atoms, a halogen atom or a cyano group; A is an organic group having at least one silyl group; Represents a haloalkyl group, a haloaryl group, or a haloaralkyl group.)

[0010]

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

The positive radiation-sensitive composition of the present invention contains a polymer containing the structural units represented by the general formulas (1) and (2). X in the general formula (1) is a halogen atom or a cyano group; Y in the general formula (2) is an alkyl group having 1 to 4 carbon atoms;
It is a halogen atom or a cyano group. X and Y
Both are preferably a halogen atom or a cyano group, and among them, a chlorine atom and a bromine atom are particularly preferably used. By introducing such a substituent on the α-carbon, the efficiency of cleavage of the main chain is improved.

A in the general formula (1) is an organic group having at least one silyl group and decomposing under the action of an acid to form an alkali-soluble group. Examples of the organic group which is decomposed by the action of an acid to generate an alkali-soluble group include a structure in which a hydrogen atom of an alkali-soluble phenolic hydroxyl group or a carboxyl group is protected by a group which is easily eliminated by the action of an acid. . Examples of the structure of A include an alkyl or arylsiloxy group, an alkoxy group having one or more alkyl or arylsilyl / siloxy groups, an aryloxy group, an alkylamino group, an arylamino group, and the like. As a specific example of A,
Dimethylsiloxy, trimethylsiloxy, diethylsiloxy, triethylsiloxy, di-n-propylsiloxy, tri-n-propylsiloxy, diphenylsiloxy, triphenylsiloxy, methylphenylsiloxy, dimethylphenylsiloxy , Methyldiphenylsiloxy group, t-butylmethylsiloxy group, t
-Butyldimethylsiloxy group, dimethylsilylmethoxy group, trimethylsilylmethoxy group, bis (dimethylsilyl) methoxy group, bis (trimethylsilyl) methoxy group, tris (trimethylsilyl) methoxy group, 1-trimethylsilylethoxy group, 2-trimethylsilylethoxy group, 1 -Trimethylsilyl-n-propoxy group, t-
Butyldimethylsilylmethoxy group, trimethylsilyl-
t-butoxy group, dimethylsilylphenoxy group, trimethylsilylphenoxy group, bis (trimethylsilyl) phenoxy group, dimethylsiloxymethoxy group, trimethylsiloxymethoxy group, triethylsiloxymethoxy group,
Bis (trimethylsiloxy) methoxy group, tris (trimethylsiloxy) methoxy group, 1-trimethylsiloxyethoxy group, 2-trimethylsiloxyethoxy group, 1-
Trimethylsiloxy-n-propoxy group, trimethylsiloxy-t-butoxy group, dimethylsiloxyphenoxy group, trimethylsiloxyphenoxy group, t-butyldimethylsiloxymethoxy group, t-butyldimethylsiloxyphenoxy group, (trimethylsilylmethyl) amino group,
(1-trimethylsilylethyl) amino group, (2-trimethylsilylethyl) amino group, (1-trimethylsilyl-n-propyl) amino group, (t-butyldimethylsilylmethyl) amino group, (trimethylsilylphenyl)
Amino group, [bis (trimethylsilyl) phenyl] amino group, (trimethylsiloxymethyl) amino group, (triethylsiloxymethyl) amino group, [bis (trimethylsiloxy) methyl] amino group, (1-trimethylsiloxyethyl) amino group, (2-trimethylsiloxyethyl) amino group, (1-trimethylsiloxy-n-propyl) amino group, (trimethylsiloxyphenyl) amino group, (t-butyldimethylsiloxymethyl) amino group,
Examples thereof include (t-butyldimethylsiloxyphenyl) amino, but are not limited thereto. Among these organic groups, those having a structure satisfying the general formula (3) are preferably used, and those in which B in the general formula (3) is an oxygen atom are more preferably used. Further, those in which D in the general formula (3) has a tertiary carbon bonded to an oxygen atom and those in which E is an oxygen atom are also extremely easily decomposed by an acid to produce an alkali-soluble group. It is preferably used. Examples of A in which B in the general formula (3) is an oxygen atom include dimethylsiloxy, trimethylsiloxy, triethylsiloxy, tri-n-propylsiloxy, triphenylsiloxy, methylphenylsiloxy, and dimethylphenylsiloxy. Group, methyldiphenylsiloxy group, t-butylmethylsiloxy group, siloxy group such as t-butyldimethylsiloxy group, dimethylsilylmethoxy group, trimethylsilylmethoxy group, 1-trimethylsilylethoxy group, 2-trimethylsilylethoxy group, 1-trimethylsilyl -N-propoxy group, t
Silylalkoxy / aryloxy groups such as -butyldimethylsilylmethoxy group, trimethylsilyl-t-butoxy group, trimethylsilylphenoxy group, dimethylsiloxymethoxy group, trimethylsiloxymethoxy group, triethylsiloxymethoxy group, 1-trimethylsiloxyethoxy group, 2- Trimethylsiloxyethoxy group, 1-trimethylsiloxy-n-propoxy group, trimethylsiloxy-t-butoxy group, dimethylsiloxyphenoxy group,
Siloxyalkoxy / aryloxy groups such as trimethylsiloxyphenoxy group, t-butyldimethylsiloxymethoxy group, and t-butyldimethylsiloxyphenoxy group. Examples of A in the general formula (3) in which D has a tertiary carbon bonded to an oxygen atom include dimethylsilyl-
t-butoxy group, trimethylsilyl-t-butoxy group,
Examples include a dimethylsiloxy-t-butoxy group, a trimethylsiloxy-t-butoxy group, a dimethylphenylsilyl-t-butoxy group, and a dimethylphenylsiloxy-t-butoxy group. Examples of A in which E in the general formula (3) is an oxygen atom include a dimethylsiloxymethoxy group,
Trimethylsiloxymethoxy group, triethylsiloxymethoxy group, 1-trimethylsiloxyethoxy group, 2-trimethylsiloxyethoxy group, 1-trimethylsiloxy-n-propoxy group, trimethylsiloxy-t-butoxy group, trimethylsiloxyphenoxy group, dimethylphenylsiloxy A siloxyalkoxy / aryloxy group such as -t-butoxy group, t-butyldimethylsiloxymethoxy group, t-butyldimethylsiloxyphenoxy group,
(Triethylsiloxymethyl) amino group, (1-trimethylsiloxyethyl) amino group, (2-trimethylsiloxyethyl) amino group, (1-trimethylsiloxy-n
-Propyl) amino group, (trimethylsiloxyphenyl) amino group, (t-butyldimethylsiloxymethyl)
Examples include siloxy group-containing amino groups such as an amino group and (t-butyldimethylsiloxyphenyl) amino group.

R ^{1 to} R ³ in the general formula (3) are a hydrogen atom or an alkyl or aryl group having 1 to 10 carbon atoms. R ¹
To R ³ may be the same or different. From the viewpoint of solubility in a developer, R ^{1 to} R ³ are more preferably a hydrogen atom or an alkyl or aryl group having 1 to 7 carbon atoms.

G in the general formula (2) is a haloalkyl group, haloaryl group or haloaralkyl group having 1 to 10 carbon atoms. Among these, high sensitivity is obtained when an organic group substituted with fluorine is used. Examples of such a fluorine-substituted organic group include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a hexafluoroisopropyl group, a 3,3,3
-Trifluoropropyl group, 2,2,3,3-tetrafluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, 1-trifluoromethylethyl group,
Fluoroalkyl groups such as 1-bis (trifluoromethyl) ethyl group, fluoroaryl groups such as 4-fluorophenyl group and pentafluorophenyl group, phenylbis (trifluoromethyl) methyl group, 1-phenyl-1-trifluoro Examples include, but are not limited to, a fluoroaralkyl group such as a methylethyl group.

The copolymerization ratio of the structural units represented by the general formulas (1) and (2) is not particularly limited, but the copolymerization ratio of the structural unit represented by the general formula (1) is 10% or more. Is preferred. Further, the polymer used in the present invention may be a polymer containing only the structural units represented by the general formulas (1) and (2), but other polymers may be used as long as the characteristics as a chemically amplified resist are not impaired. May be a copolymer containing the above monomer unit. 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-hydroxystyrene, maleic acid, maleic anhydride, crotonic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, acrylonitrile, methacrylonitrile, crotononitrile, maleinonitrile, fumaronitrile, metaconnitrile, citraconitrile , Itaconitrile, acrylamide, methacrylamide, crotonamide, maleamide, fumaramide, mesaconamide, citraconamide, itaconamide, vinylaniline, vinylpyrrolidone, vinylimidazole and the like. When the other monomer structure has an acidic functional group, it may include a monomer unit having a structure in which a hydrogen atom of the acidic functional group is substituted with an acid leaving group such as A described above.

The weight-average molecular weight of the polymer containing the structural units represented by the general formulas (1) and (2) used in the present invention is from 5,000 to 5,000 in terms of polystyrene measured by GPC.
1500000, more preferably 10,000 to 1000
000.

The positive radiation-sensitive composition of the present invention contains an acid generator that 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 herein may be any as long as it can decompose a group that decomposes under the action of the acid of the general formula (1) by the generated acid. Onium salts, halogen-containing compounds,
Examples thereof include a diazoketone compound, a diazomethane compound, a sulfone compound, a sulfonate compound, and a sulfonimide compound.

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.

A dissolution inhibitor can be added to the positive radiation-sensitive composition of the present invention. 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-telorahydrothiophene-
1,1-dioxide and the like can be mentioned.

A high molecular compound can also be used as a dissolution inhibitor used in the present invention. 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 100 parts by weight of the polymer containing the structural units represented by the general formulas (1) and (2).
It is 150 parts by weight, preferably 5 to 100 parts by weight, more preferably 5 to 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 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.

[0033]

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.

Synthesis Example 1 α-Chloromethacrylic acid and an equimolar amount of trimethylsilylmethanol were dissolved in toluene. After adding sulfuric acid as a catalyst, water was removed while distilling off, and the mixture was reacted for 20 hours. The solvent and unreacted raw materials were distilled off from the obtained toluene solution to obtain γ-trimethylsilyl-α-chloroacrylate.

Synthesis Example 2 α-bromoacrylic acid was reacted with thionyl chloride in tetrahydrofuran to obtain α-bromoacrylic acid chloride. The obtained α-bromoacrylic acid chloride was reacted with equimolar 4-aminophenol in tetrahydrofuran in the presence of triethylamine to obtain α-bromoacrylic acid-4-hydroxyphenylamide. Further, the obtained α-bromoacrylic acid-4-hydroxyphenylamide was reacted with equimolar amounts of trimethylsilyl chloride and triethylamine in tetrahydrofuran to obtain α-bromoacrylic acid-4-trimethylsiloxyphenylamide.

Synthesis Example 3 2-dimethylphenylsilylethyl-α-chloroacrylate was obtained in the same manner as in Synthesis Example 1 except that 2-dimethylphenylsilylethanol was used instead of trimethylsilylmethanol.

Synthesis Example 4 2,3-Dichloropropionic acid, equimolar p-hydroxyphenethyl alcohol and a catalytic amount of p-toluenesulfonic acid were dissolved in toluene, water was removed while distilling off, and the reaction was carried out for 20 hours. . The obtained toluene solution was washed with water, dried, and toluene was distilled off to obtain p-hydroxyphenethyl-2,3-dichloropropionate.
Triethylamine was allowed to act on the obtained p-hydroxyphenethyl-2,3-dichloropropionate in tetrahydrofuran to obtain p-hydroxyphenethyl-α-chloroacrylate. p-hydroxyphenethyl-
Equimolar amounts of trimethylchlorosilane and triethylamine were allowed to act on α-chloroacrylate in tetrahydrofuran to obtain p-trimethylsiloxyphenethyl-α-chloroacrylate.

Synthesis Example 5 Trimethylsilyl-t-butyl-α-chloroacrylate was obtained in the same manner as in Synthesis Example 1 except that trimethylsilyl-t-butanol was used instead of trimethylsilylmethanol.

Example 1 γ-trimethylsilylmethyl methacrylate and 2,2-
Dichloroethyl-α-cyanoacrylate copolymer (copolymerization ratio 45:55, weight average molecular weight 39000)
3 g, triphenylsulfonium triflate 150 m
g was 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, it was heated at 90 ° C. for 2 minutes,
A resist film having a thickness of 0.5 μm was obtained. The resist film was irradiated with an electron beam in a pattern at an acceleration voltage of 20 kV using an electron beam exposure apparatus, heated at 90 ° C. for 3 minutes, and then developed with an aqueous solution of tetramethylammonium hydroxide. At an exposure of 4.5 μC / cm ² , a pattern of 0.26 μm was obtained.

Example 2 A copolymer of α-bromoacrylic acid-4-trimethylsiloxyphenylamide obtained in Synthesis Example 2 and 2,2,2-trifluoroethyl methacrylate (copolymerization ratio: 32:
68, 3 g of weight average molecular weight 22000) and 150 mg of triphenylsulfonium triflate were dissolved in propylene glycol monomethyl ether acetate to give 0.1 g.
The mixture was filtered through a μm filter to obtain a resist composition. Using the obtained resist composition, a resist film was obtained in the same manner as in Example 1, and was developed by irradiation with an electron beam. 4.7μ
A pattern of 0.26 μm was obtained at an exposure dose of C / cm ² .

Example 3 A copolymer of 2-dimethylphenylsilylethyl-α-chloroacrylate obtained in Synthesis Example 3 and 1,1-bis (trifluoromethyl) ethyl-α-chloroacrylate (copolymerization ratio: 73 : 27, weight average molecular weight 41000)
3 g, triphenylsulfonium triflate 150 m
g was dissolved in propylene glycol monomethyl ether acetate and filtered through a 0.1 μm filter to obtain a resist composition. Using the obtained resist composition, a resist film was obtained in the same manner as in Example 1, and was irradiated with an electron beam and developed. 0.24 μm at 3.5 μC / cm ² exposure
Was obtained.

Example 4 A copolymer of p-trimethylsiloxyphenethyl-α-chloroacrylate obtained in Synthesis Example 4 and 1-phenyl-1-trifluoromethylethyl-α-chloroacrylate (copolymerization ratio 51:49) , Weight average molecular weight 2900
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. Using the obtained resist composition, a resist film was obtained in the same manner as in Example 1, and irradiated with an electron beam.
Development was performed. 0.21 at 3.4 μC / cm ² exposure
A μm pattern was obtained.

Example 5 Trimethylsilyl-t-butyl-α obtained in Synthesis Example 5
3 g of a copolymer of -chloroacrylate and 2,2,3,3-tetrafluoropropyl-α-chloroacrylate (copolymerization ratio 55:45, weight average molecular weight 28000),
150 mg of triphenylsulfonium triflate was dissolved in propylene glycol monomethyl ether acetate, and filtered with a 0.1 μm filter to obtain a resist composition. Using the obtained resist composition, a resist film was obtained in the same manner as in Example 1, and was developed by irradiation with an electron beam. A pattern of 0.21 μm was obtained with an exposure of 3.2 μC / cm ² .

Example 6 The same experiment as in Example 5 was performed except that an i-line stepper was used as an exposure apparatus. 0.3 at an exposure of 30 mJ / cm ² .
A pattern of 4 μm was obtained.

Comparative Example 1 Poly (t-butyl-α-chloroacrylate) (weight average molecular weight 280) was used in place of the copolymer used in Example 1.
A resist film was obtained in the same manner as in Example 1 except that (00) was used, and the film was developed by irradiation with an electron beam. 6.5 μC / c
A pattern of 0.35 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 copolymer of γ-trimethylsilyl-α-chloroacrylate and methyl methacrylate obtained in Synthesis Example 1 (copolymerization ratio: 40: 6)
0, a weight average molecular weight of 36000), and a resist film was obtained in the same manner as in Example 1 and developed by irradiating an electron beam. A pattern of 0.36 μm was obtained at an exposure amount of 6.8 μC / cm ² , which was not sufficient in terms of sensitivity and resolution.

Comparative Example 3 The same experiment as in Comparative Example 2 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 55 μm was obtained, and the characteristics were not sufficient in terms of sensitivity and resolution.

Comparative Example 4 Poly (2,2,2) was used in place of the copolymer used in Example 1.
A resist film was obtained in the same manner as in Example 1 except that 3,3-tetrafluoropropyl-α-chloroacrylate) (weight average molecular weight 32,000) was used, and was developed by irradiation with an electron beam. The pattern was not resolved even at an exposure dose of 50 μC / cm ² .

[0049]

As described above, the positive-type radiation-sensitive composition of the present invention contains a polymer containing a specific acrylate monomer unit and an acid generator that generates an acid upon irradiation with radiation. By using a positive radiation-sensitive composition, it has become possible to obtain a composition with high resolution and high sensitivity.

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[Procedure amendment]

[Submission date] April 19, 2000 (2004.1.
9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0002

[Correction method] Change

[Correction contents]

[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 vacuum ultraviolet rays, X-rays and electron beams is being studied, and resists corresponding to such light sources are required.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

The positive radiation-sensitive composition of the present invention contains a polymer containing the structural units represented by the general formulas (1) and (2). X in the general formula (1) is a halogen atom or a cyano group; Y in the general formula (2) is an alkyl group having 1 to 4 carbon atoms;
It is preferably a halogen atom or a cyano group, and among them, a chlorine atom and a bromine atom are particularly preferably used. The introduction of such substituent on the α- carbon, dew
The efficiency of the polymer main chain cleavage reaction in the optical part is improved
You. As a result, the molecular weight is lower than in the unexposed area,
An image of the trust is obtained. Such a backbone cleavage reaction
Is a high energy line such as electron beam, vacuum ultraviolet ray, X-ray
It occurs particularly easily when using a source.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

The weight-average molecular weight of the polymer containing the structural units represented by the general formulas (1) and (2) used in the present invention is from 5,000 to 5,000 in terms of polystyrene measured by GPC.
1500000, more preferably 5000 to 10000
00, more preferably 6,000 to 50,000.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

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. This thin film is subjected to pattern exposure using radiation such as ultraviolet rays, far ultraviolet rays, vacuum ultraviolet rays , electron beams, X-rays, and the like, and a fine pattern can be obtained by baking and developing after exposure. Especially electron beam, vacuum
The effect is large in the case of pattern exposure using ultraviolet rays and X- rays, and the effect becomes more pronounced in the case of using an electron beam.

Continued on the front page F term (reference) 2H025 AA01 AA02 AB08 AB16 AD03 BE00 BE10 CB14 CB15 CB34 CB41 CB52 EA04 EA10 FA03 FA17

Claims (9)

[Claims] 1. A polymer containing a structural unit represented by the following general formulas (1) and (2) and an acid generator that generates an acid upon irradiation with radiation, wherein A in the polymer is an acid. A positive-type radiation-sensitive composition, characterized in that the composition is an organic group that is decomposed by an organic group to generate an alkali-soluble group. Embedded image Embedded image (X is a halogen atom or a cyano group, Y is a C 1-4
Is an alkyl group, a halogen atom or a cyano group. A
Is an organic group having at least one silyl group, and G is a group having 1 to 1 carbon atoms.
0 represents a haloalkyl group, a haloaryl group, or a haloaralkyl group. ) 2. The positive radiation-sensitive composition according to claim 1, wherein Y in the general formula (2) is a halogen atom or a cyano group. 3. The positive radiation-sensitive composition according to claim 1, wherein A in the general formula (1) is an organic group represented by the following general formula (3). (B is an oxygen atom or a nitrogen atom, D is a single bond or an alkylene group or an arylene group having 1 to 10 carbon atoms, E is a single bond or an oxygen atom, R ^{1 to} R ³ are a hydrogen atom or an alkyl having 1 to 10 carbon atoms. Group, an aryl group, and R ^{1 to} R ³
May be the same or different. ) 4. The positive radiation-sensitive composition according to claim 3, wherein B in the general formula (3) is an oxygen atom. 5. The positive radiation-sensitive composition according to claim 4, wherein D in the general formula (3) is an organic group having a tertiary carbon bonded to an oxygen atom. 6. The positive radiation-sensitive composition according to claim 3, wherein E in the general formula (3) is an oxygen atom. 7. The positive radiation-sensitive composition according to claim 1, wherein G in the general formula (2) is an organic group substituted with fluorine. 8. A positive radiation-sensitive composition according to any one of claims 1 to 6, which is applied onto a substrate to be processed, dried, exposed,
Manufacturing method of the pattern to be developed. 9. The method according to claim 7, wherein the exposure is performed by an electron beam.