JPH0534922A - Resist composition - Google Patents

Abstract

PURPOSE:To provide a resist material having excellent resist characteristics such as sensitivity, resolution and shelf stability and fit for lithography with far UV or KrF excimer laser light. CONSTITUTION:This resist compsn. contains alkali-soluble phenol resin, a compd. capable of producing an acid under irradiation with active rays of light and a compd. which can be crosslinked in the presence of the acid. The alkali-soluble phenol resin is alkali-soluble partially hydrogenated phenol resin and the compd. which can be crosslinked in the presence of the acid is glycoluril-formaldehyde resin contg. >=90wt.% tetralkoxymethyl glycoluril monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist composition, and more particularly to a resist material which can be patterned well by irradiation with far ultraviolet rays, KrF excimer laser light or the like. The resist composition of the present invention is particularly suitable as a negative resist for fine processing of semiconductor devices.

[0002]

2. Description of the Related Art When a semiconductor element is manufactured by fine processing using a resist, 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.
Then, an image (pattern) is obtained by a lithographic technique in which it is developed to form a negative or positive image. The resist remaining on the silicon wafer is used as a protective film, etching is performed, and then the resist film is removed to complete the microfabrication.

By the way, in recent years, IC, LSI and VL
Along with the high integration, high density, and miniaturization of semiconductor devices for SI, there is a demand for a technique for forming a fine pattern of 1 μm or less. However, it is extremely difficult to form a fine pattern of 1 μm or less with high precision by the conventional photolithography technique using near-ultraviolet light or visible light, and the yield is significantly reduced.

Therefore, instead of the conventional photolithography using light (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 (wavelength 200 to 260 nm) and KrF excimer laser light are used. A lithography technique using (a krypton fluoride laser that emits light having a wavelength of 248 nm) or the like has been studied. A number of high-level properties are required for the resist material, which is the center of this lithography technique, and among them, the most important are sensitivity, resolution, etching resistance and storage stability.

However, conventionally developed resist materials are
Not all of these performances are fully satisfied, and improvement in performance has been strongly desired.

For example, a negative resist such as polyglycidyl methacrylate has high sensitivity but is inferior in resolution and dry etching resistance. Further, a positive resist such as polymethylmethacrylate has good resolution but poor sensitivity and dry etching resistance.

In recent years, various proposals have been made for increasing the sensitivity of resists using an acid catalyst and a chemical amplification effect. For example, novolac resin (base polymer), methylolmelamine (crosslinking agent), and photoacid generator (phtoac).
Negative resists having a composition consisting of an id generator have been attracting attention. A negative resist is produced by utilizing the phenomenon that methylolmelamine crosslinks and insolubilizes a novolak resin by using an acid generated by light as a catalyst.

However, when a novolac resin type photoresist is exposed to deep ultraviolet rays, the light absorption of the resist itself is too large, resulting in insufficient sensitivity and resolution, and it is impossible to form a fine pattern. Judging from the high performance standards required by, it is not enough.

Recently, (1) poly (hydroxystyrene), (2) as a cross-linking agent, a 5-membered ring, a 6-membered ring having no carbon-carbon double bond or carbon-nitrogen double bond in its skeleton,
A compound obtained by converting a bicyclo compound into an alcohol
A resist composition having a composition comprising (3) a photo-acid generator is proposed (JP-A-2-15270). However, the sensitivity and resolution of this resist composition are still insufficient. Tetrabutoxymethylolacetylene urea is also shown as a crosslinking agent, but the ratio of mononuclear bodies is not disclosed.

Therefore, there has been a strong demand for the development of a new resist having the above-mentioned performance in balance.

[0011]

An object of the present invention is to provide a resist material having excellent resist properties such as sensitivity, resolution and storage stability.

Another object of the present invention is to provide a resist material suitable for lithography using deep ultraviolet rays having a short wavelength or KrF excimer laser light.

Another object of the present invention is to provide a resist composition which is particularly suitable as a negative resist for fine processing of semiconductor devices.

As a result of intensive studies to solve the problems of the prior art, the inventors of the present invention have found that in a resist composition having a composition of a base polymer, a crosslinking agent and a photo-acid generator, By using an alkali-soluble partially hydrogenated phenol resin as a molecule and a glycoluril formaldehyde resin containing 90% by weight or more of a tetraalkoxymethylglycoluril mononuclear body as a photoacid generator, sensitivity, resolution and It has been found that a resist composition having excellent storage stability and improved process latitude can be obtained.

The resist composition of the present invention has a better transmittance of the specific glycoluril formaldehyde resin itself for far-ultraviolet rays and KrF excimer laser light than methylolmelamine. By combining with a highly hydrogenated partially hydrogenated phenolic resin, the transmittance of the resist itself is significantly improved. Then, the cross-sectional shape (profile) of the resist pattern becomes vertical rather than reverse tapered, and the resolution is improved. The present invention has been completed based on these findings.

[0016]

Thus, according to the present invention, a resist composition containing an alkali-soluble phenolic resin, a compound capable of generating an acid upon irradiation with actinic rays, and a compound capable of crosslinking in the presence of an acid. In, the alkali-soluble phenol resin is an alkali-soluble partially hydrogenated phenol resin, and the compound capable of crosslinking in the presence of an acid is a glycoluril-formaldehyde resin containing 90% by weight or more of tetraalkoxymethylglycoluril mononuclear body. A resist composition is provided.

The present invention will be described in detail below. (Alkali-soluble partially hydrogenated phenol resin) In the present invention, an alkali-soluble partially hydrogenated phenol resin is used as the base polymer. The partially hydrogenated phenolic resin has a better transmittance for far ultraviolet rays and KrF excimer laser light than ordinary alkali-soluble phenolic resins. By using this alkali-soluble partially hydrogenated phenolic resin, sensitivity, resolution, etching resistance and storage stability are improved.

Alkali-soluble partially hydrogenated phenolic resins include, for example, condensation reaction products of phenols and aldehydes, condensation reaction products of phenols and ketones,
It is a resin obtained by hydrogenating an alkali-soluble phenol resin such as a vinylphenol polymer and an isopropenylphenol polymer.

In the hydrogenation, the hydrogenation rate is usually 0.1 to 7
0%, preferably 1 to 50%, more preferably 3 to 40
Perform so that it is within the range of%. If the hydrogenation rate exceeds 70%, the hydrogenated phenol resin becomes insoluble in alkali, which makes it unsuitable as a base polymer for resists. Further, if the hydrogenation rate is too low, the effect of improving the performance by hydrogenation becomes small.

Specific examples of the phenols used here include monohydric phenols such as phenol, cresol, xylenol, ethylphenol, propylphenol, butylphenol and phenylphenol; resorcinol, pyrocatechol, hydroquinone, bisphenol A, pyrogallol and the like. Polyhydric phenols; and the like.

Specific examples of aldehydes include formaldehyde, acetaldehyde, benzaldehyde, terephthalaldehyde and the like. Specific examples of the ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone and the like. These condensation reactions can be performed according to a conventional method.

The vinylphenol polymer is selected from a homopolymer of vinylphenol and a copolymer of vinylphenol and a component copolymerizable with vinylphenol. Specific examples of the copolymerizable component include acrylic acid, methacrylic acid, styrene, maleic anhydride, maleic imide, vinyl acetate, acrylonitrile, and derivatives thereof.

The isopropenylphenol-based polymer is selected from homopolymers of isopropenylphenol and copolymers with a component copolymerizable with isopropenylphenol. Specific examples of the copolymerizable component include acrylic acid, methacrylic acid, styrene, maleic anhydride, maleic imide, vinyl acetate, acrylonitrile, and derivatives thereof.

The hydrogenation reaction of the phenol resin can be carried out by a known method. The phenol resin is dissolved in an organic solvent and hydrogen is introduced in the presence of a homogeneous or heterogeneous hydrogenation catalyst. It is achieved by The concentration of the phenol resin solution in the hydrogenation reaction is 1 to 70% by weight, preferably 1 to 40% by weight. The solvent is not particularly limited as long as it dissolves the phenol resin without adversely affecting the hydrogenation catalyst. The hydrogenation catalyst is not particularly limited as long as it is a metal or non-metal catalyst having an activity of hydrogenation reaction. As specific examples, Fe, Co, Ni, Ru, Rh, Pd, Ir,
Os, Pt, Cr, Te, Mn, Ti, V, Zr, M
o, W-based hydrogenation catalysts. These catalysts
They can be used alone or in combination of two or more.

The reaction temperature for the hydrogenation reaction is usually 0 to 30.
The temperature is 0 ° C, preferably 20 to 150 ° C. It is possible even at 300 ° C or higher, but it is not preferable because side reactions easily occur. The hydrogen pressure is from atmospheric pressure to 400 kg / cm ² , preferably 5 to 200 kg / cm ² . After the hydrogenation reaction, the catalyst can be removed from the hydrogenation reaction resin solution by reprecipitation purification, precipitation method, centrifugation method, filtration method, or the like.

The alkali-soluble partially hydrogenated phenolic resin may be used alone or in combination of two or more kinds.

In the resist composition of the present invention, in order to improve developability, storage stability, heat resistance, etc., if necessary, for example, a copolymer of styrene and acrylic acid, methacrylic acid or maleic anhydride. , A copolymer of an alkene and maleic anhydride, a vinyl alcohol polymer, a vinylpyrrolidone polymer, rosin, shellac and the like can be added.

The amount of these optional components added is 0 with respect to 100 parts by weight of the alkali-soluble partially hydrogenated phenolic resin.
-50 parts by weight, preferably 5-20 parts by weight.

(Glycoluril formaldehyde resin) In the present invention, a glycoluril formaldehyde resin containing 90% by weight or more of a tetraalkoxymethylglycoluril mononuclear body is used as a compound (crosslinking agent) capable of crosslinking in the presence of an acid. .

The glycoluril formaldehyde resin used in the present invention cross-links the partially hydrogenated phenol resin in the active light irradiation region using an acid derived from a compound (photoacid generator) which produces an acid upon irradiation with active light as a catalyst. To insolubilize and reduce the solubility in an alkaline developer.

Glycoluril formaldehyde resin produced industrially is a relatively large amount of tetraalkoxymethylglycoluril oligomer (2 to 5 nuclide).
And by-products containing a methylol group, catalyst residues, those containing a solvent, even when using such a resin as a cross-linking agent,
It is not possible to obtain sufficiently satisfactory sensitivity, resolution and storage stability.

On the other hand, when a glycoluril formaldehyde resin containing 90% by weight or more of a tetraalkoxymethylglycoluril mononuclear body is used, the resin itself has a good light transmittance in the deep ultraviolet and KrF excimer laser light regions. In comparison with the case where a melamine formaldehyde resin (methylol melamine) is used as a cross-linking agent, the transmittance of the resist itself to far ultraviolet rays and KrF excimer laser light is improved.

In addition, an alkali-soluble partially hydrogenated phenolic resin having a transmittance for far ultraviolet rays and KrF excimer laser light which is better than that of a normal alkali-soluble phenolic resin is used as a base polymer in combination with the above-mentioned specific glycoluril formaldehyde resin. As a result, sensitivity, resolution, residual film thickness, storage stability, etc. are all significantly improved. The resist pattern obtained by using the resist composition of the present invention has a vertical profile rather than an inverse taper profile.

In the present invention, the tetraalkoxymethylglycoluril mononuclear body means a compound represented by the following general formula.

[0035]

[Chemical 1] [In the formula, R represents an alkyl group having 1 to 5 carbon atoms. ]

As the tetraalkoxymethylglycoluril mononuclear body, tetramethoxymethylglycoluril is particularly preferable from the viewpoint of sensitivity and resolution.

The content of the tetraalkoxymethylglycoluril mononuclear body in the glycoluril formaldehyde resin needs to be 90% by weight or more, preferably 93% by weight, more preferably 95% by weight or more. By using the glycoluril formaldehyde resin having such a specific composition, the sensitivity, resolution, storage stability, process latitude (exposure latitude) and the like are improved. When the content of the tetraalkoxymethylglycoluril mononuclear body is less than 90% by weight,
The sensitivity and the residual film thickness are reduced, and the profile of the resist pattern is inversely tapered, so that the resolution is reduced.

To obtain a glycoluril formaldehyde resin having a tetraalkoxymethylglycoluril mononuclear content of 90% by weight or more, for example, (1) an industrially produced glycoluril formaldehyde resin or an ordinary synthesis method is used. (2) US Pat. No. 3,48, wherein the uricol uriryl formaldehyde resin synthesized by the method described above is purified by distillation, recrystallization, column separation treatment, etc.
There is a method of synthesizing by a special synthesizing method described in No. 8,350.

The amount of the glycoluril formaldehyde resin used in the present invention is usually 0.2 to 8 with respect to 100 parts by weight of the alkali-soluble partially hydrogenated phenol resin.
It is 0 part by weight, preferably 1 to 30 parts by weight. If the amount is less than 0.2 parts by weight, it becomes impossible to form a pattern, and if the amount exceeds 80 parts by weight, undeveloped portions are likely to occur.

(Compound capable of generating an acid upon irradiation with actinic ray) The compound capable of generating an acid upon irradiation with an actinic ray (also referred to as a photo-acid generator or a compound capable of cleaving an acid) used in the present invention is exposure radiation. Is a compound that generates or releases an acid in response to the wavelength of. The photoacid generator is not particularly limited as long as it is a substance that forms a Bronsted acid or a Lewis acid upon irradiation with actinic rays, and various known compounds and mixtures can be used, and examples thereof include onium salts and halogenated compounds. Examples thereof include organic compounds, halogenated organic compounds / organic metal mixtures, o-quinonediazide compounds, organic acid ester compounds, organic acid amide compounds, organic acid imide compounds and the like.

Specific examples of onium salts include diazonium salts, ammonium salts, iodonium salts, sulfonium salts, phosphonium salts, arsonium salts and oxonium salts.

The halogenated organic compound is not particularly limited as long as it is a halide of an organic compound, and various known compounds can be used. Specific examples thereof include a halogen-containing oxadiazole compound and a halogen-containing triazine. Compounds, halogen-containing acetophenone compounds, halogen-containing benzophenone compounds, halogen-containing sulfoxide compounds, halogen-containing sulfone compounds, halogen-containing thiazole compounds, halogen-containing oxazole compounds, halogen-containing trizole compounds, halogen-containing 2-pyrone Examples of various compounds include system compounds, halogen-containing aliphatic hydrocarbon compounds, halogen-containing aromatic hydrocarbon compounds, other halogen-containing heterocyclic compounds, and sulfenyl halide compounds.

Further, as halogenated organic compounds, tris (2,3-dibromopropyl) phosphate, tris (2,3-dibromo-3-chloropropyl) phosphate, chlorotetrabromobutane, hexachlorobenzene, hexabromobenzene, hexa Bromocyclododecane, hexabromobiphenyl, tribromophenyl allyl ether, tetrachlorobisphenol A, tetrabromobisphenol A, bis (bromoethyl ether)
Tetrabromobisphenol A, bis (chloroethyl ether) tetrachlorobisphenol A, tris (2,
3-dibromopropyl) isocyanurate, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxyethoxy-3,5
-Dibromophenyl) propane, etc., compounds used as halogen-based flame retardants; dichlorodiphenyltrichloroethane, benzenehexachloride, 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, ethyl-
4,4-dichlorobenzilate, 2,4,5,4'-tetrachlorodiphenyl sulfide, 2,4,5,4 '
-Compounds used as organic chloro pesticides such as tetrachlorodiphenyl sulfone are also included.

Specific examples of the o-quinonediazide compound include 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester and 1,2-naphthoquinonediazide-5-sulfonic acid ester. Ester, 2,1-naphthoquinonediazide-4-
Sulfonic acid ester, 2,1-naphthoquinonediazide-
5-sulfonic acid ester, sulfonic acid ester of other quinonediazide derivative; 1,2-benzoquinonediazide-4-sulfonic acid chloride, 1,2-naphthoquinonediazide-4-sulfonic acid chloride, 1,2-naphthoquinonediazide-5 Sulfonyl chloride, 2,1-
Naphthoquinonediazide-4-sulfonic acid chloride,
2,1-naphthoquinonediazide-5-sulfonic acid chloride, sulfonic acid chlorides of other quinonediazide derivatives, and the like.

Specific examples of the organic acid ester include carboxylic acid ester and sulfonic acid ester.

Specific examples of the organic acid amide include carboxylic acid amide and sulfonic acid amide.

Specific examples of the organic acid imide include carboxylic acid imide and sulfonic acid imide.

These photoacid-generating compounds can be used alone or in admixture of two or more.
The compounding amount of the photo-acid generating compound is usually 0.01 to 5 with respect to 100 parts by weight of the alkali-soluble partially hydrogenated phenol resin.
It is 0 part by weight, preferably 0.2 to 20 parts by weight.
If it is less than 0.01 parts by weight, pattern formation becomes impossible,
If the amount exceeds 50 parts by weight, a development residue tends to occur, and in any case, the resist performance is deteriorated.

(Resist Composition) The resist composition of the present invention is usually used by dissolving it in a solvent to apply it to a substrate to form a resist film.

Examples of the solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, cycloheptanone and butyrolactone; alcohols such as n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol and t-butyl alcohol. Ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dioxane; alcohol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; propyl formate, butyl formate , Propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, etc. Monooxycarboxylic acid esters such as methyl 2-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, etc. cellosolve esters;
Propylene glycols such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ethyl 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, diethylene glycol Diethylene glycols such as methyl ethyl ether; halogenated hydrocarbons such as trichloroethylene; aromatic hydrocarbons such as toluene and xylene; dimethylacetamide, dimethylformamide, N
-Methyl acetamide, a polar solvent such as N-methylpyrrolidone; and the like. You may use these individually or in mixture of 2 or more types.

The resist composition of the present invention may contain additives such as a surfactant, a storage stabilizer, a sensitizer, a striation inhibitor, a plasticizer and an antihalation agent, if necessary.

As a developer for the resist composition of the present invention, an aqueous alkali solution is used. Specifically, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium silicate, and ammonia; ethylamine, propylamine, etc. Primary amines; secondary amines such as diethylamine and dipropylamine; tertiary amines such as trimethylamine and triethylamine; alcohol amines such as diethylethanolamine and triethanolamine; tetramethylammonium hydroxide, tetraethylammonium hydroxy And quaternary ammonium salts such as trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide and trimethylhydroxyethylammonium hydroxide; It is.

Further, if necessary, an appropriate amount of a water-soluble organic solvent such as methanol, ethanol, propanol or ethylene glycol, a surfactant, a storage stabilizer, a resin dissolution inhibitor and the like can be added to the above alkaline aqueous solution.

The resist composition of the present invention can be used to form a resist film by applying the solvent solution thereof to the surface of a substrate such as a silicon wafer by a conventional method and then removing the solvent by drying. As the coating method, spin coating is particularly preferred.

For the exposure, a fine pattern can be formed by irradiating short wavelength ultraviolet light or KrF excimer laser light using a deep ultraviolet irradiation device or an excimer laser device in which krypton / fluorine gas is enclosed.

By performing a heat treatment (post-exposure bake) after the light irradiation, the reaction between the acid and the cross-linking agent (acid-catalyzed reaction) is promoted, and the sensitivity can be further increased.

[0057]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The parts and% in the examples and comparative examples are based on weight unless otherwise specified.

The content of tetraalkoxymethylglycoluril mononuclear body in glycoluril formaldehyde resin is a value measured by the following measuring method.

<Measurement Method of Mononuclear Body Content> Measurement was carried out by the GPC method (gel permeation chromatography) under the following conditions. Column: TSKgel G2000HLX and TSKg
el G3000HLX in-series column temperature: 40 ° C. developing solution: tetrahydrofuran flow rate: 0.8 ml / min detector: differential refractometer sample concentration: 0.5% by weight

Reference Example 1 A glycoluril formaldehyde resin was synthesized from glycoluril, formalin and methanol according to a conventional method. The mononuclear body content ratio of this resin was measured by the GPC method under the above-mentioned conditions to be 7
It was 5.6%.

The obtained resin was purified by the recrystallization method,
A glycoluril formaldehyde resin having an improved mononuclear content was obtained. Recrystallization was performed as follows.

Using isopropyl alcohol as a solvent, the above resin was dissolved at 40 to 60 ° C., and this was recrystallized by cooling. The precipitated crystals were filtered with a Buchner funnel, washed several times with a recrystallization solvent, and then vacuum dried for 24 hours. With respect to the glycoluril formaldehyde resin thus obtained, the mononuclear body content ratio was measured by the GPC method.

By changing the solution concentration, the dissolution temperature, the cooling temperature and the number of recrystallizations of the above resins, glycoluril formaldehyde resins shown in Table 1 having different mononuclear body contents were obtained.

[0064]

[Table 1]

Example 1 Hydrogenated polyvinylphenol (hydrogenation rate = 8%, weight average molecular weight = 4900) 1
Reference Example 1 as a compound capable of crosslinking in the presence of 00 parts of acid
Each glycoluril formaldehyde resin prepared in 1
2 parts of 5 parts, 1.7 parts of bisphenol S-2,3-dibromopropyl ether, and 0.01 parts of fluorochemical surfactant.
Dissolve in 380 parts of ethyl methoxypropionate to give 0.1
Each resist solution was prepared by filtering with a μm polytetrafluoroethylene filter (manufactured by Millipore).

After coating each of the above resist solutions on a silicon wafer with a spinner, baking is performed at 90 ° C. for 90 seconds,
A resist film having a thickness of 1.0 μm was formed. The far-ultraviolet irradiation device (PL made by Canon Inc., PL
A-521FA) and a test mask were used for exposure. Then, after exposing and baking at 130 ° C. for 60 seconds,
A pattern was obtained by developing with an aqueous tetramethylammonium hydroxide solution (concentration 2.38%) at 23 ° C. for 1 minute by a dipping method.

Each wafer on which a pattern was formed was taken out and evaluated for sensitivity and residual film thickness. The residual film thickness was calculated from the film thickness measured with a film thickness meter (Alpha Step 200, manufactured by Tenko Co., Ltd.). The measurement results are shown in Table 2. In Table 2,
The resist numbers 1 and 2 are comparative examples.

As can be seen from Table 2, the higher the content ratio of mononuclear body in the glycoluril formaldehyde resin is,
The sensitivity and the residual film thickness were improved.

[0069]

[Table 2]

Example 2 Hydrogenated polyvinylphenol (hydrogenation rate = 12%, weight average molecular weight = 4800)
100 parts, 20 parts of each glycoluril formaldehyde resin prepared in Reference Example 1 as a compound that can be crosslinked in the presence of an acid, tetrabromobisphenol S diallyl ether 1.5 parts, 0.01 parts of a fluorochemical surfactant and propylene glycol. Each resist solution was prepared by dissolving in 390 parts of monomethyl ether acetate and filtering with a 0.1 μm polytetrafluoroethylene filter.

Each of the above resist solutions was applied on a silicon wafer by a spinner and then baked at 90 ° C. for 90 seconds,
A resist film having a thickness of 1.0 μm was formed. KrF excimer laser stepper NSR is applied to the resist film of each wafer.
Exposure was performed using 1505EX (manufactured by Nikon Corporation, NA = 0.42) and a test mask. Next, after exposure at 110 ° C. for 60 seconds and baking, it was developed with an aqueous tetramethylammonium hydroxide solution at 23 ° C. for 1 minute by a dipping method and rinsed with ultrapure water to obtain a negative pattern.

Each wafer on which a pattern was formed was taken out and observed with an electron microscope to evaluate the resolution. The evaluation results are shown in Table 3. The resist numbers 6 to 7 in Table 3 are comparative examples.

As can be seen from Table 3, the higher the mononuclear content of the glycoluril formaldehyde resin,
The pattern profile becomes vertical and the resolution is improved.

[0074]

[Table 3]

Example 3 Hydrogenated polyvinylphenol (hydrogenation rate = 10%, weight average molecular weight = 4800)
100 parts, 20 parts of each glycoluril formaldehyde resin prepared in Reference Example 1 as a compound capable of crosslinking in the presence of an acid (synthetic only resin or recrystallized product D), tetrabromobisphenol A-2,3-dibromopropyl ether 2.5 parts and 0.01 part of a fluorine-containing surfactant were dissolved in 390 parts of propylene glycol monomethyl ether acetate, and filtered through a 0.1 μm polytetrafluoroethylene filter to prepare each resist solution.

Each of these resists was heat-aged at 40 ° C., and the sensitivity was measured by the same method as in Example 1. The resist using a synthetic glycoluril formaldehyde resin as a cross-linking agent showed a change in sensitivity with the lapse of time such as 3 days and 7 days. However, as a cross-linking agent,
The resist using the recrystallized product D of No. 1 did not show any change in sensitivity even after aging for 7 days.

Example 4 Hydrogenated polyvinylphenol (hydrogenation rate = 7%, weight average molecular weight = 7000) 1
Reference Example 1 as a compound capable of crosslinking in the presence of 00 parts of acid
15 parts of the glycoluril formaldehyde resin (recrystallized product C) prepared in 4 above, 4.0 parts of p-toluenesulfonic acid phenyl ester, and 0.01 part of a fluorochemical surfactant were added to propylene glycol monomethyl ether acetate 390.
Part, and filtered through a 0.1 μm polytetrafluoroethylene filter to prepare a resist solution.

The resist solution was applied onto a silicon wafer with a spinner and baked at 90 ° C. for 90 seconds to form a resist film having a thickness of 1.0 μm. The resist film on this wafer is used as a KrF excimer laser stepper NS.
Exposure was performed using R 1505EX (manufactured by Nikon Corporation, NA = 0.42) and a test mask. Next, 130 ℃
After exposure for 60 seconds and baking, it was developed with an aqueous tetramethylammonium hydroxide solution at 23 ° C. for 1 minute by an immersion method and rinsed with ultrapure water to obtain a negative pattern.

The wafer on which the pattern was formed was taken out and observed with an electron microscope to evaluate the resolution. As a result, a 0.45 μm pattern having a substantially vertical shape was resolved.

Example 5 Hydrogenated polyvinylphenol (hydrogenation rate = 12%, weight average molecular weight = 4900)
100 parts, 15 parts of glycoluril formaldehyde resin (recrystallized product C) prepared in Reference Example 1 as a compound capable of crosslinking in the presence of an acid, bisphenol A-2,3-dibromopropyl ether 2.0 parts, fluorine-based interface 0.01 part of the activator was dissolved in 390 parts of propylene glycol monomethyl ether acetate, and filtered through a 0.1 μm polytetrafluoroethylene filter to prepare a resist solution.

The resist solution was applied onto a silicon wafer with a spinner and baked at 90 ° C. for 90 seconds to form a resist film having a thickness of 1.0 μm. The resist film on this wafer is used as a KrF excimer laser stepper NS.
Exposure was performed using R 1505EX (manufactured by Nikon Corporation, NA = 0.42) and a test mask. Next, 110 ℃
After exposure for 60 seconds and baking, it was developed with an aqueous tetramethylammonium hydroxide solution at 23 ° C. for 1 minute by an immersion method and rinsed with ultrapure water to obtain a negative pattern.

The wafer on which the pattern was formed was taken out and observed with an electron microscope to evaluate the resolution. As a result, a 0.40 μm pattern having a substantially vertical shape was resolved.

[0083]

According to the present invention, a resist composition having a good balance of sensitivity, resolution, residual film thickness, storage stability and the like can be obtained. The resist composition of the present invention is a pattern forming material suitable for lithography using short wavelength light,
In particular, it is suitable as a negative resist for fine processing of semiconductor elements.

Claims (3)

[Claims] 1. In a resist composition containing an alkali-soluble phenol resin, a compound capable of generating an acid upon irradiation with actinic rays, and a compound capable of crosslinking in the presence of an acid, the alkali-soluble phenol resin is an alkali-soluble partially hydrogenated compound. A resist composition, which is a phenol resin and a compound capable of crosslinking in the presence of an acid is a glycoluril formaldehyde resin containing 90% by weight or more of a tetraalkoxymethylglycoluril mononuclear body. 2. A glycoluril formaldehyde resin containing tetraalkoxymethyl glycoluril mononuclear compound
The resist composition according to claim 1, which contains 3% by weight or more. 3. The resist composition according to claim 1, wherein the tetraalkoxymethylglycoluril mononuclear body is tetramethoxymethylglycoluril mononuclear body.