JPH09230595A - Resist composition and its utilization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resist compsn. retaining high transparency by making polycylic polyolefin resin carry an acid-unstable structure. SOLUTION: This resist compsn. contains at least one kind of resin repeatedly carrying at least one kind of acid-unstable structure on polycyclic polyolefin resin as a base resin and a photosensitive acid generating material as essential components. The acid-unstable structure has a group represented by an acid- unstable group, an acid-labile group, an acid-decomposable group, etc., known in the field of a chemical amplification type resist and the group is decomposed by an acid and increases the alkali solubility of the base resin. The polycyclic polyolefin resin is a known resin such as a polymer obtd. by ring opening polymn. of a monomer having a norbonane skeleton.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist composition used for the production of ICs, LSIs and the like, and its use, and more particularly to radiation such as deep ultraviolet rays such as ArF excimer lasers, X-points, and charged particle beams such as electron beams. The present invention relates to a resist composition suitable as a resist useful for ultrafine processing of a semiconductor device using and a use thereof.

[0002]

2. Description of the Related Art When manufacturing a semiconductor device, a resist is applied to the surface of a silicon wafer to form a photosensitive film, which is irradiated with light to form a latent image, which is then developed to form a negative or positive image. The image is obtained by the lithographic technology. By the way, as semiconductors become highly integrated, highly densified, miniaturized, and speeded up in ICs, LSIs, and VLSIs, demands for microfabrication of elements have increased, and at present, a technique for forming a micropattern of 0.5 μm or less. Is required. However, it is extremely difficult to form such a fine pattern by conventional lithography using near-ultraviolet rays or visible light, and the yield is significantly reduced. Therefore, instead of the conventional photolithography using near-ultraviolet light having a wavelength of 350 to 450 nm, in order to increase the resolution of exposure, far-ultraviolet light having a short wavelength (short-wavelength ultraviolet light),
KrF excimer laser with wavelength 248nm, wavelength 193n
A lithographic technique using an ArF excimer laser of m.

A novolak resin is used as a base polymer for lithography utilizing near-ultraviolet light. Although this resin has good transparency to ultraviolet light having a wavelength of 350 to 450 nm, it has a shorter wavelength. Since the transmittance is extremely deteriorated with respect to light having a short wavelength such as deep ultraviolet rays or KrF or ArF excimer laser, when novolac resin is used as the base polymer, sufficient sensitivity cannot be obtained. It is known that it has a bad shape.

It is a well-known technique to use a polyvinylphenol derivative as a base resin of a chemically amplified resist for KrF excimer laser exposure, and a hydrogenated polyvinylphenol derivative for the purpose of further improving the transmittance is a base polymer. As a method (Japanese Patent Application Laid-Open No. 5-249
673, etc.) are known. Further, in lithography such as ArF excimer laser exposure in which light having a shorter wavelength is used, it is not preferable that an aromatic ring that absorbs a shorter wavelength is present in the resin. For this reason, it has been investigated to use a methacrylic acid ester-based copolymer resin having no aromatic ring (Japanese Patent Laid-Open No. 7-199467). However, research on lithography using an ArF excimer laser has not yet reached a practical level.
The emergence of a new resist is at a stage where it is desired to obtain an excellent balance of resist properties.

Amorphous polycyclic polyolefin resins used as molding materials are known as highly transparent resins (JP-A-1-168725, JP-A-1-311120, JP-A-1). -190
No. 726, No. 3-14882, No. 3
-122137, Japanese Patent Laid-Open No. 4-63807). However, it has not been known to use these resins as base resins for resists.

[0006]

Under the above-mentioned conventional techniques, the inventors of the present invention have earnestly studied to obtain a new resist composition capable of exposing to a wavelength, and as a result, the polycyclic polyolefin resin has acid instability. If a resin supporting the structure is used,
The inventors have found that they retain high transparency even at short wavelengths, particularly at wavelengths of 250 nm or less, and have completed the present invention.

[0007]

Thus, according to the present invention, at least one resin (A) having an acid-labile structure supported on a base resin, and a photosensitive acid-generating substance (B).
There is provided a resist composition comprising as an essential component, wherein the base resin of the resin (A) is a polycyclic polyolefin resin.

Hereinafter, the present invention will be described in detail. The resin (A) used in the present invention is a resin in which at least one kind of acid labile structure is repeatedly carried on a polycyclic polyolefin resin which is a base resin. In the present invention, the acid labile structure is a structure having a group known as an acid labile group, an acid labile group, an acid decomposable group, etc., which is known in the field of chemically amplified resist, and is decomposed by an acid. , A structure containing a group that increases the alkali solubility of the base resin. Specifically, a t-butyl ester group, t-butyl carbonate described in JP-B-2-27660,
A tertiary alkyloxy group such as a tertiary alkyloxy group, a t-amyloxy group and a t-amyloxycarbonyl group described in JP-B-5-69420, a tertiary alkyloxycarbonyl group, a tertiary alkyloxycarbonyloxy group; Acetal structure described in JP-B-5-43451; Ketal structure described in JP-A-2-1641436; 1-alkylcycloalkyloxy group, 1-alkylcycloalkyloxycarbonyl described in Japanese Patent Application No. 6-261054. Group; a substituted allyloxy group having two or more substituents described in Japanese Patent Application No. 7-284583, a substituted allyloxycarbonyl group, a substituted allyloxycarbonyloxy group; and the like. These groups may be directly bonded to the base resin or may be bonded via a divalent or higher valent organic group.

Among such acid labile structures,
a structure containing a t-butyl group (a t-butyloxycarbonyl group, a t-butyloxy group, a t-butyloxycarbonyloxy group and a group in which these are bonded to a base resin through a divalent organic group), t A structure containing an amyl group (t-amyloxy group, t-amyloxycarbonyl group and those bonded to a base resin via a divalent organic group), a 1-alkylcycloalkyloxy group Structure (1-alkylcycloalkyloxy group, 1-alkylcycloalkyloxycarbonyl group and those bonded to the base resin via a divalent organic group), a substituted allyloxy group having two or more substituents Containing structure (substituted allyloxy group having two or more substituents, substituted allyloxycarbonyl group, substituted allyloxycarbonyl group Shea groups and these base resin and 2
(Bonded via a valent organic group) is a preferred example.

The polycyclic polyolefin resin used as the base resin in the present invention is described in JP-A-1-168725.
JP-A-1-311120 and JP-A-1-19072.
No. 6, JP-A-3-14882, and JP-A 3-1.
22137, JP-A-4-63807, and the like. Specifically, the resin is a ring-opening polymer of a monomer having a norbornene skeleton (hereinafter referred to as norbornene-type monomer), its hydrogenated product, or norbornene-type resin. It is an addition polymerization product of a monomer and other olefinic monomers, and is preferably a hydrogenated product of a ring-opening polymer of a norbornene-type monomer. The hydrogenation rate of the hydrogenated product of the ring-opening polymer of the norbornene-type monomer is preferably 80% or more, more preferably 90% or more.
In the case of an addition polymerization product of a norbornene-type monomer and an olefin-based monomer, the amount of the other olefin-based monomer used is 50 mol% or less, preferably 30 mol% or less, and more preferably 20 mol% with respect to the norbornene-type monomer. % Or less.

The weight average molecular weight of the resin (A) used in the present invention is a polystyrene equivalent value measured by GPC (gel permeation chromatography) method, and the lower limit is usually 5,000, preferably 10,000. The upper limit is usually 100,000, preferably 20,000. If it is less than this lower limit range, it becomes brittle, and conversely if it exceeds this upper limit, the resolution may deteriorate.

The ratio of the acid-labile structure supported in the resin (A) is 100% based on all the repeating structural units in the base resin.
, The number of structural units carried by the acid labile structure is 10 to 100, preferably 20 to 80, more preferably 30 to 70. If the ratio of the acid labile structure is too high, the pattern may become thin due to the deterioration of the image quality.

The monomers as the raw material of the resin (A) described above include (1) norbornene type monomers and (2)
Other olefinic monomers capable of addition polymerization are mentioned,
These can be appropriately mixed and used according to the purpose. When only a monomer having no acid-labile structure is used as a raw material, or when the amount of the monomer having an acid-labile structure used is small, a ratio of the above range is obtained by a modification reaction that introduces an acid-labile structure later. When the resin can support an acid labile structure and a sufficient amount of a monomer as a raw material having an acid labile structure introduced therein is used, it is reacted with other monomer components by a conventional method, if necessary.

Specific examples of the norbornene-type monomer (1) having an acid-labile structure are given in the above-mentioned publication and JP-A-2-
Known monomers such as JP-A-227424 and JP-A-2-276842, which are, for example, norbornene, dicyclopentadiene, dimethanooctahydronaphthalene, dimethanocyclopentadienonaphthalene, and cyclopentadiene 3 to 4 Polymers, adducts of cyclopentadiene and tetrahydroindene; alkyl, alkylidene and aromatic substituted derivatives of these norbornene type monomers;
Substituted or unsubstituted norbornene-type monomer with halogen,
Examples thereof include monomers to which polar groups such as a hydroxyl group, an ester group, an alkoxy group, a cyano group, an amide group, an imide group, and a silyl group are added.

Specific examples of such a monomer include 2-norbornene, 5-methyl-2-norbornene, 5,5-dimethyl-2-norbornene, and 5-norbornene.
Ethyl-2-norbornene, 5-butyl-2-norbornene, 5-ethylidene-2-norbornene, 5-methoxycarbonyl-2-norbornene, 5-cyano-2-norbornene, 5-methyl-5-methoxycarbonyl-2.
-Norbornene, 5-phenyl-2-norbornene, 5
-Phenyl-5-methyl-2-norbornene, 5-hexyl-2-norbornene, 5-octyl-2-norbornene, 5-octadecyl-2-norbornene, etc .; dicyclopentadiene, 2,3-dihydrodicyclopentadiene; A monomer in which one or more cyclopentadiene is added to norbornene, a derivative or substituent similar to the above, for example, 1,4: 5,8-dimethano-2,3-cyclopentadieno-1-1, 2, 3, 4, 4a, 5, 8, 8a-
Octahydronaphthalene, 6-methyl-1,4: 5,8
-Dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 1,4: 5,10: 6,9-trimethano-2,3-cyclopentadieno-1,2, Three
4,4a, 5,5a, 6,9,9a, 10,10a-dodecahydroanthracene, etc .; cyclopentadiene monomer having a polycyclic structure which is polymerized by Diels-Alder reaction, and derivatives and substitutions similar to the above Body, for example, dicyclopetadiene, 2,3-dihydrodicyclopentadiene and the like; adduct of cyclopentadiene and tetrahydroindene and the like, derivatives and substitution products similar to the above, for example, 1,4-methano-1, 4,4a, 4b, 5,8,8
a, 9a-octahydrofluorene, 5,8-methano-
2,3-cyclopentadieno-1,2,3,4,4a,
5,8,8a-octahydronaphthalene and the like; and the like. Among these, 6-methyl-1,4: 5,8
-Dimethano-1,4,4a, 5,6,7,8,8a-dimethanooctahydronaphthalene such as octahydronaphthalene (MTD), dicyclopentadiene (DC
P), 5-ethylidene-2-norbornene (ENB) and mixtures of these two are preferred.

Specific examples of the other addition-polymerizable olefinic monomer (2) include ethylene, propylene and 1-
Butene, 3-methyl-1-butene, 1-pentene, 3-
Methyl-1-pentene, 4-methyl-1-pentene, 1
Α-olefins such as hexene and 1-octene; alicyclic olefins such as cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, and 2- (2-methylbutyl) -1-cyclohexene; 3a, 5 , 6,7a-Detrahydro-4,7-methano-1H-indene and other non-norbornene type formula olefins; 1,4-hexadiene, 1,6-octadiene,
2-methyl-1,5-hexadiene, 6-methyl-1,
Non-conjugated dienes such as 5-heptadiene, 7-methyl-1,6-octadiene, cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 1,5-hexadiene, norbornadiene; 2-propenyl-
Trienes such as 2,5-norbornadiene, 1,3,5-octatriene, and 1,4,9-decatriene,
Aromatic olefinic monomers are exemplified.

An acid labile structure is introduced into each of these monomers by a conventional method, and a monomer in which an acid labile structure is introduced is used. JP-A-1-168725 and JP-A-1-16825
311120, JP-A-1-190726,
JP-A-3-14882, JP-A-3-122137
The resin (A) used in the present invention can be obtained by synthesizing the resin by the method described in JP-A No. 4-63807. The monomer having the acid labile structure introduced is, for example, 2
-Carbonyloxymethyl propene was prepared according to a conventional method.
It can be obtained by introducing an acid labile group (oxycarbonyl type) by a transesterification reaction, an acid halide reaction with an alcohol, or a reaction of esterifying a carboxyl group with a dehydration condensing agent. When a polycyclic compound is synthesized by reacting it with a norbornene-type monomer such as pentadiene, a norbornene-type monomer having an acid labile structure introduced therein can be obtained.

The photosensitive acid-generating substance (B) (hereinafter referred to as PAG) used in the present invention is not particularly limited as long as it is a substance capable of generating Bronsted acid or Lewis acid when exposed to activating radiation. , Onium salts, halogenated organic compounds, quinonediazide compounds, α, α′-bis (sulfonyl) diazomethane compounds, α-carbonyl-α′-sulfonyldiazomethane compounds, sulfone compounds, organic acid ester compounds, organic acid amide compounds, Known compounds such as organic acid imide compounds can be used. Examples of onium salts include diazonium salts, ammonium salts, iodonium salts such as diphenyliodonium triflate, sulfonium salts such as triphenylsulfonium triflate, phosphonium salts, arsonium salts, and oxonium salts.

As the halogenated organic compound, a halogen-containing oxadiazole compound, a halogen-containing triazine compound, a halogen-containing acetophenone compound, a halogen-containing benzophenone compound, a halogen-containing sulfoxide compound, a halogen-containing sulfone compound,
Halogen-containing thiazole compounds, halogen-containing oxazole compounds, halogen-containing triazole compounds, halogen-containing 2-pyrone compounds, other halogen-containing heterocyclic compounds, halogen-containing aliphatic hydrocarbon compounds,
Examples thereof include halogen-containing aromatic hydrocarbon compounds and sulfenyl halide compounds. Specifically, tris (2,
3-dibromopropyl) phosphate, tris (2,3
-Dibromo-3-chloropropyl) phosphate, tetrabromochlorobutane, hexachlorobenzene, hexabromobenzene, hexabromocyclododecane, hexabromobiphenyl, allyltribromophenyl ether, tetrachlorobisphenol A, tetrabromobisphenol A, tetrachlorobisphenol A bis (chloroethyl) ether, tetrabromobisphenol A bis (bromoethyl) ether, bisphenol A bis (2,3-dichloropropyl) ether, bisphenol A bis (2,3-dibromopropyl) ether, tetrachlorobisphenol A's screw (2,3-
Dichloropropyl) ether, bis (2,3-dibromopropyl) ether of tetrabromobisphenol A,
Tetrachlorobisphenol S, tetrabromobisphenol S, tetrachlorobisphenol S bis (chloroethyl) ether, tetrabromobisphenol S bis (bromoethyl) ether, bisphenol S bis (2,3-dichloropropyl) ether, bisphenol S bis (2,3-dibromopropyl) ether,
Tris (2,3-dibromopropyl) isocyanurate, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4- (2-hydroxyethoxy) -3,5- Halogen-based flame retardants such as dibromophenyl) propane, dichlorodiphenyltrichloroethane, pentachlorophenol, 2,4,6-trichlorophenyl 4-nitrophenyl ether, 2,4
-Dichlorophenyl 3'-methoxy-4'-nitrophenyl ether, 2,4-dichlorophenoxyacetic acid,
4,5,6,7-tetrachlorophthalide, 1,1-bis (4-chlorophenyl) ethanol, 1,1-bis (4
-Chlorophenyl) -2,2,2-trichloroethanol, 2,4,4 ', 5-tetrachlorodiphenyl sulfide, 2,4,4', 5-tetrachlorodiphenyl sulfone and other organic chloro-based pesticides are exemplified. It

Specific examples of the quinonediazide compound include:
1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,1-naphthoquinonediazide-4-sulfonic acid ester Ester, 2,1-benzoquinonediazide-5
Sulfonic acid ester of quinonediazide derivative such as sulfonic acid ester, 1,2-benzoquinone-2-diazide-4-sulfonic acid chloride, 1,2-naphthoquinone-2-diazide-4-sulfonic acid chloride, 1,2-
Sulfonic acid of quinonediazide derivative such as naphthoquinone-2-diazide-5-sulfonic acid chloride, 1,2-naphthoquinone-1-diazide-6-sulfonic acid chloride and 1,2-benzoquinone-1-diazide-5-sulfonic acid chloride Examples include chloride.

The α, α-bis (sulfonyl) diazomethane compounds include unsubstituted, symmetrically or asymmetrically substituted alkyl group, alkenyl group, aralkyl group,
Examples include α, α-bis (sulfonyl) diazomethane having an aromatic group or a heterocyclic group. Specific examples of the α-carbonyl-α-sulfonyldiazomethane compound include an α- having an unsubstituted, symmetrically or asymmetrically substituted alkyl group, alkenyl group, aralkyl group, aromatic group, or heterocyclic group. Carbonyl-α-
Examples thereof include sulfonyldiazomethane. Specific examples of the sulfone compound include a sulfone compound having an unsubstituted, symmetrically or asymmetrically substituted alkyl group, alkenyl group, aralkyl group, aromatic group, or heterocyclic group, a disulfone compound, and the like. Examples of the organic acid ester include carboxylic acid ester, sulfonic acid ester, and phosphoric acid ester, and examples of the organic acid amide include carboxylic acid amide, sulfonic acid amide, and phosphoric acid amide. Examples thereof include carboxylic acid imide, sulfonic acid imide, and phosphoric acid imide.

The PAG as described above is also used as a resist for KrF excimer laser, but among them, it does not have an aromatic ring and absorbs light near the wavelength of ArF excimer laser (185.5 to 220 nm). Compounds having a small amount, for example, compounds described in the formulas (II) or (III) in columns 9 to 10 of JP-A-7-199467 and specific examples thereof, that is, cyclohexylmethyl (2-oxocyclohexyl) Sulfonium trifluoromethane sulfonate, dicyclohexyl (2-oxocyclohexyl) sulfonium trifluoromethane sulfonate,
Examples thereof include dicyclohexylsulfonylcyclohexanone, dimethyl (2-oxocyclohexyl) sulfonyltrifluoromethanesulfonate, triphenylsulfonium trifluoromethanesulfonate, diphenyliodonium trifluoromethanesulfonate, and N-hydroxysuccinimide trifluoromethanesulfonate.

These PAGs may be used alone or in combination of two or more. The blending amount of these PAGs is usually 0.01 part by weight, preferably 0.2 part by weight, with respect to 100 parts by weight of the resin used in the present invention.
The upper limit is usually 50 parts by weight, preferably 30 parts by weight.
If it is less than 0.01 parts by weight, it becomes impossible to form a pattern. If the amount exceeds 50 parts by weight, problems such as easy occurrence of undeveloped residue and deterioration of pattern shape occur, and in any case, it is not preferable in terms of resist performance.

In the present invention, the resist composition comprising the resin and PAG is used by dissolving it in a solvent. As the solvent, those generally used as a solvent for a resist composition can be used, and specific examples thereof include ketones such as acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, cyclopentanone, cyclohexanone; n-propanol. , I-propanol, n-
Alcohols such as butanol, i-butanol, t-butanol, cyclohexanol; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dioxane; ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol mono Alcohol ethers such as ethyl ether; Esters such as propyl formate, butyl formate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate; 2-
Oxycarboxylic acid esters such as methyl oxypropionate, ethyl 2-oxypropionate, methyl 2-methoxypropionate and ethyl 2-methoxypropionate; cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, butyl cellosolve acetate. Propylene glycols such as propylene glycol, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, etc .; diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, etc. The di Tylene glycols; halogenated hydrocarbons such as trichloroethylene; aromatic hydrocarbons such as toluene and xylene; polarities such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylacetamide, N-methylpyrrolidone Examples thereof include solvents, and these may be used alone or in combination of two or more.

In the present invention, those generally added to resist compositions as additives, for example, silicon-based or fluorine-based surfactants, storage stabilizers, sensitizers, stres, which are generally added to resist compositions, are used. A compatible additive such as an anti-relation agent may be contained.

In the composition of the present invention, the resin (A)
Is affected by the action of an acid that suppresses the acid generator upon irradiation with radiation, and the solubility of the irradiated portion changes. The composition of the present invention acts as a positive resist by using an alkaline developer. By using the polycyclic polyolefin resin as the base resin, resist characteristics such as dry etching resistance, resolution, and dissolution inhibiting effect are improved.

Among the resist compositions of the present invention, the resist composition of the present invention in which the amount of the photo-sensitive acid generator (PAG) is 3 parts by weight is applied to a film thickness of 7,000 angstroms. When the film is irradiated with light having a wavelength of 193 nm, the light transmittance is 20% or more, preferably 30.
% Or more, more preferably 40% or more is practical. The light transmittance measured here is 1 m in thickness.
This is the light transmittance (%) measured by applying a resist to a quartz plate of m with a film thickness of 7,000 Å and irradiating far ultraviolet rays of 193 nm.

The resist composition of the present invention usually uses an alkaline aqueous solution as a developing solution, and specific examples thereof include an aqueous solution of an inorganic alkali such as sodium hydroxide, potassium hydroxide, sodium silicate, and ammonia; ethylamine,
Aqueous solution of primary amines such as propylamine; Aqueous solution of secondary amines such as diethylamine and dipropylamine;
Aqueous solutions of tertiary amines such as trimethylamine and triethylamine; Aqueous solutions of alcohol amines such as diethylethanolamine and triethanolamine; tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide , An aqueous solution of a quaternary ammonium hydroxide such as trimethyl hydroxyethyl ammonium hydroxide. If necessary, a water-soluble organic solvent such as methanol, ethanol, propanol, and ethylene glycol, a surfactant, and a resin dissolution inhibitor may be added to the aqueous alkali solution.

In the pattern forming method of the present invention, the above-mentioned resist composition of the present invention is applied onto a substrate by a method such as spin coating to give an arbitrary film thickness (usually 0.01 μ in dry film thickness).
m to 1 μm) and a wavelength of 190 to
Exposure is performed using a light source having a wavelength of 250 nm. Further, after the film is formed, before exposure, the temperature is in a range where the resist is not deteriorated by heat, usually 90 to 190 ° C., preferably 1
It is better to bake at 20 to 170 ° C. If the temperature exceeds this range and is low, a surface hardly soluble layer is generated, and conversely, if it is high, thermosetting or thermal decomposition may occur, which is not preferable. A that can be exposed through a mask as an exposure light source
When using rF excimer laser light, the effects of the present invention are particularly exhibited. Further, it is usual to perform a bake after the exposure, but this bake after the exposure is at a normal temperature, that is, 70 to
It is 180 ° C. For the development, the developer described above may be used.

[0030]

As described above, according to the present invention, a resist composition having excellent resist characteristics such as sensitivity and resolution can be obtained.
Further, the resist composition of the present invention sufficiently transmits short-wavelength light such as far-ultraviolet light and ArF excimer laser light and electron beams, so that a finely processed semiconductor element can be obtained.

[0031]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The parts and percentages in each example are based on weight unless otherwise specified. The light transmittance is measured when a resist composition prepared by adjusting the amount of a photosensitive acid generator (PAG) to 3 parts by weight is applied to a resist film having a film thickness of 7,000 Å and irradiating light having a wavelength of 193 nm. Is a value obtained by measuring the transmittance (%) of.

(Synthesis Example) Hydrogenated poly 8-methyl-8
-T-butoxycarbonyltetracyclo [4,4,0,
1 ^2,5, 1 ^7,10] -3-dodecene t- butyl alcohol 1mol, dried dimethylaniline 1mol dissolved in dry ether 200 ml, with stirring under ice-cooling, was added dropwise methacrylic chloride 1mol. After stirring for another 2 hours after the completion of dropping, water was added to dissolve the solid, and the mixture was extracted with ether. The ether layer after extraction was washed with a 10% sulfuric acid aqueous solution and then dried. The solvent was distilled off under reduced pressure, the residue was distilled, and t-butyl methacrylate was purified. 0.15 mol of t-butyl methacrylate thus obtained and dicyclopentadiene 0.15 mol
Mol was mixed and stirred at -20 ° C for 2 hours to obtain 5-butoxycarbonyl-5-methoxy-2-norbornene (yield 96%). Further, the obtained 5-methoxy-5-
t-butoxycarbonyl-2-norbornene 0.1mo
1 and 0.05 mol of dicyclopentadiene are mixed,
Hydroquinone WP 0.005mol as polymerization inhibitor
In addition, the mixture was reacted at 200 ° C. for 3 hours to give 8-methyl-8-
t-Butoxycarbonyltetracyclo [4,4,0,1]
^2,5, to obtain a 1 ^7,10] -3-dodecene.

[0033] In the polymerization vessel, 8-methyl -8-t-butoxide was obtained by the above method butoxycarbonyl tetracyclo [4,4,0,1 ^2,5, 1 ^7,10] -3-dodecene 100
mol was dissolved in toluene so as to have a monomer concentration of 10% by weight, and 0.70 mol of 1-hexene as a molecular weight regulator and diethyl aluminum chloride of 0.1.
25 mol and tungsten hexachloride 0.15 mol were added in this order, and the mixture was reacted at 70 ° C. for 1 hour. After the reaction, coagulate and dry with isopropyl alcohol to give poly 8-methyl-
8-t-butoxycarbonyltetracyclo [4,4,
0,1 ^2,5, to give the 1 ^{7,1 0]} -3-dodecene. Subsequently, a 20% by weight aqueous solution of triethanolamine was added to half of the obtained polymer solution, and after stirring, the aqueous layer was separated,
The organic layer was transferred into a pressure resistant reactor, and palladium-carbon (palladium on activated carbon: Pd concentration 5%) 1 was used as a catalyst.
0 parts by weight was added, and under hydrogen gas pressure of 10 kg / cm ² ,
The mixture was reacted at 150 ° C. for 4 hours and hydrogenated. After cooling the obtained reaction liquid, the catalyst was filtered off from the reaction system, and methanol was added to the filtrate to coagulate and dry the polymer. The resulting hydrogenated poly 8-methyl -8-t-butoxycarbonyl-tetracyclo [4,4,0,1 ^2,5, 1 ^7,10] -3
The hydrogenation rate of dodecene was about 95% from the ¹ H-NMR spectrum.

A 20% by weight aqueous solution of triethanolamine was added to half of the remaining polymer solution, and after stirring, the aqueous layer was separated, the organic layer was transferred into a pressure resistant reaction vessel, and palladium-carbon (palladium on activated carbon supported as a catalyst) was used. : Pd concentration 5%) 10 parts by weight was added, and the hydrogen gas pressure was 10 kg / cm.
^{Under 2} conditions, the mixture was reacted at 110 ° C. for 3 hours and hydrogenated. After cooling the obtained reaction liquid, the catalyst was filtered off from the reaction system, and methanol was added to the filtrate to coagulate and dry the polymer. The resulting hydrogenated poly 8-methyl -8-t-butoxycarbonyl-tetracyclo [4,4,0,1 ^2,5, 1
The hydrogenation rate of ^7,10 ] -3-dodecene was about 80% from the ¹ H-NMR spectrum.

(Examples 1 to 5 and Comparative Examples 1 to 3) The resin and the photosensitive acid generating substance were dissolved in cyclohexanone according to the formulation shown in Table 1 so that the resin concentration was 14% by weight, and then 0 A resist solution was prepared by filtering with a 0.2 μm polytetrafluoroethylene filter (manufactured by Millipore). This resist solution was spin-coated on a silicon wafer and then baked at 120 ° C. for 60 seconds to form a resist film having a film thickness of 7,000 Å. This wafer is used as an ArF excimer stepper (N
A = 0.55) and a test reticle were used for exposure. Subsequently, each wafer was immersed in a tetramethylammonium hydroxide aqueous solution for 1 minute to obtain a positive pattern. The transmittance and resolution of the obtained resist film were as shown in Table 1.

[0036]

[Table 1]

[Resin column] What is the resin in the examples? This is the resin obtained in the synthesis example. -The resin of Comparative Example 1 is a copolymer of 4-hydroxyvinylphenol and t-butyl methacrylate at a molar ratio of 57:43 (charge ratio). -The resin of Comparative Example 2 is 5 of 4-hydroxyvinylphenol and 3-methyl-2-butenyl methacrylate.
It is a copolymer of 4:46 (molar ratio charged). -The resin of Comparative Example 3 is a copolymer of 4-hydroxyvinylphenol and 4- (t-butyloxycarbonylmethyl) vinylphenol in a ratio of 50:50 (molar ratio charged). [Column of Acid Generator] PAG1 = triphenyl sulfonate triflate PAG2 = the following formula (1)

Embedded image PAG3 = Equation (2)

Embedded image

From these results, it can be seen that if the transmittance is low, a sufficient pattern cannot be obtained by ArF excimer laser exposure.

Claims (4)

[Claims] 1. A resist composition comprising, as essential components, at least one resin (A) having an acid-labile structure supported on a base resin and a photosensitive acid-generating substance (B). A resist composition, wherein the base resin (A) is a polycyclic polyolefin resin. 2. The polycyclic polyolefin resin is a ring-opening polymer of a monomer having a norbornene skeleton, a hydrogenated product thereof, or an addition polymer of a monomer having a norbornene skeleton and other olefinic monomers. The resist composition described. 3. The light transmittance at a wavelength of 193 nm of the resist film coated on the substrate so that the thickness becomes 7,000 angstrom when the amount of the photosensitive acid-generating substance (B) in the resist composition is 3 parts by weight. Is 40% or more, The resist composition according to claim 1 or 2. 4. A step of applying the resist composition according to claim 1 onto a substrate, and a wavelength of 190 to 2
A pattern forming method comprising a step of exposing using a light source having a wavelength of 50 nm.