JPH03107165A - Resist composition - Google Patents

Abstract

PURPOSE:To obtain the compsn. having a high sensitivity, resolution, etching resistance, and preservable stability, by constituting a resist material which can form patterns by irradiation with far UV rays, etc., of a copolymer having a specific constitutional unit and a compd. which can be acid-cloven by the irradiation with active rays. CONSTITUTION:The compd. having the constitutional unit expressed by general formulas I and II in the molecular chain is incorporated into this compsn. In the formulas, R<1> and R<3> are a hydrogen atom or alkyl group; R<2> is an alkyl group. In the formula III and IV, R<4> and R<5> are a hydrogen atom, halogen atom or alkyl group; R<6> are an alkyl group or aryl group. For example, 2- methoxystyrene, etc., are used as the more specific example of the monomer to give the constitutional unit of the formula I. Styrene, etc., are used as the more specific example of the monomer to give the constitutional unit of the formula II. The compd. which can be acid-cloven by the irradiation with active rays, i.e., photoacid generator, is satisfactory if the compd. is the material which generates Brphinsted acid or Lewis acid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a resist composition, and more particularly to a resist material that can be patterned by irradiation with deep ultraviolet rays, KrF excimer laser light, or the like. The resist composition of the present invention is particularly suitable as a positive resist for microfabrication of semiconductor devices.

[Conventional technology]

When manufacturing semiconductor devices through microfabrication using resist, a resist is applied to the surface of a silicon wafer to form a photoresist film, which is irradiated with light to form a latent image, which is then developed to create a negative or positive image. Images (patterns) are obtained using lithography technology. After etching is performed using the resist remaining on the silicon wafer as a protective film, the resist film is removed to complete the microfabrication.

By the way, in recent years, IC, LSI, etc.: VLS
With the increasing integration, density, and miniaturization of semiconductor devices, a technology for forming fine patterns of 1 μm or less is required. However, with conventional photolithography techniques that use near ultraviolet rays or visible light, it is extremely difficult to accurately form fine patterns of 1 μm or less, and the yield is significantly reduced.

For this reason, instead of conventional photolithography that uses light (ultraviolet light with a wavelength of 350 to 450 nm), in order to increase the resolution of exposure, far ultraviolet light (short wavelength ultraviolet light) *K r F excimer laser light with a short wavelength is used. (Wavelength 249
Lithography technology using a krypton fluoride laser (which emits nanometer light) is being researched.

Resist materials, which are central to this lithography technology, are required to have many advanced properties, among which the most important are sensitivity, resolution, etching resistance, and storage stability.

In other words, (1) the resist is required to have good sensitivity to the light used for exposure and radiation from electronic cotton, and the smaller the amount of irradiation required to make the resist visible, the better the sensitivity. It is. (2) The smaller the minimum dimension that can be processed using the resist, the higher the resolution, but for this reason the resist does not swell in the developer, and
It is necessary to have high contrast. (3
) As a protective film, the resist must be resistant to etching, and in particular, it is required to be resistant to dry etching using plasma or accelerated ions. (4) The resist is required to have storage stability and not undergo alteration or deterioration.

However, conventionally developed resist materials do not fully satisfy all of these properties, and there has been a strong desire for improved performance.

For example, negative resists such as polyglycidyl methacrylate have high sensitivity but poor resolution and dry etching resistance. Positive resists such as polymethyl methacrylate have good resolution but poor sensitivity and dry etching resistance.

Furthermore, when a novolac resin-based positive photoresist is exposed to deep ultraviolet rays, the resist itself absorbs too much light, resulting in insufficient sensitivity and resolution, making it impossible to form a good fine pattern.

Recently, increasing the sensitivity of resists using acid catalysts and chemical amplification effects has attracted attention, and for example, resists for microfabrication have been developed that are composed of a three-component system of a base polymer, a light generating agent, and an intoxicant. In this method, an intoxicant reacts with the acid generated by light as a catalyst, and the solubility of the base polymer changes, resulting in a positive or negative resist.

For example, a positive resist consisting of a novolac resin, a light generating agent, and a dissolution inhibitor is known. The dissolution inhibitor has a dissolution inhibiting effect on the novolak resin, and
It reacts with acids and exhibits a dissolution promoting effect. In addition, a type of polymer that blocks the functional groups that control the solubility of the base polymer to make it insoluble, and then removes the block with the acid generated by light to restore the solubility of the polymer base material in the developer. Positive resists are also known.

However, conventional resists are still not sufficient in view of recent high performance standards.

Therefore, there has been a strong desire to develop a new resist with well-balanced performance.

[Problem to be solved by the invention]

An object of the present invention is to provide a resist material that is highly balanced in resist properties such as sensitivity, resolution, etching resistance, and storage stability.

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

Another object of the present invention is to provide a resist composition particularly suitable as a positive resist for microfabrication of semiconductor devices.

As a result of intensive research in order to solve the problems of the above-mentioned conventional technology, the present inventors discovered a resin containing a copolymer having a specific structural unit and an alkali-soluble phenol resin as the base polymer. It has been discovered that a resist composition capable of achieving the above object can be obtained by using a resist composition containing a compound (light generating agent) that can be acid-cleaved by irradiation with actinic rays, and based on this knowledge, The present invention has now been completed.

[Means for Solving the Problems] Thus, according to the present invention, (A) the general formula [
[I]] and a copolymer having a structural unit represented by the general formula (I[); and (B) a compound that can be acid-cleaved by irradiation with actinic rays.

1 (however, In the above formula, R1 and R3 is a hydrogen atom 1 ma or 10-OR', 4 and R6 is a hydrogen atom, Heroge or alkyl group, 8 is an alkyl group or a Represents a lyl group.

) Further, according to the present invention, (A) a copolymer having a structural unit represented by the formula [N and the general formula [117] in the molecular chain, (B) a compound that can be acid-cleaved by irradiation with actinic rays. , and (C) an alkali-soluble phenolic resin.

The present invention will be explained in detail below.

(Copolymer) The copolymer used in the present invention is poorly soluble in alkali,
In addition, the irradiated area is modified by light irradiation, eliminating the dissolution inhibiting effect and functioning as a positive resist that increases alkali solubility.By combining with a light generator, a highly sensitive positive resist can be created. can get.

Specific examples of the monomer providing the structural unit of general formula [11] used in the present invention include 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 2-ethoxystyrene, 3-ethoxystyrene, 4-
Ethoxystyrene, 4-n propoxystyrene, 4-isopropoxystyrene, 4-n butoxystyrene, 4-n
t-butoxystyrene, 2-(2-methoxyphenyl)-
Propene, 2-(3-methoxyphenyl)-propene,
2-(4-methoxyphenyl)-propene, 2-(2
-ethoxyphenyl)-propene, 2-(3-ethoxyphenyl)-propene, 2-(4-ethoxyphenyl)
-propene, 2-(4-n propoxyphenyl)-propene, 2-(4-isopropoxyphenyl)-propene, 2-(4-butoxyphenyl)-propene, 2-
(4-t-butoxyphenyl)-propene, 4-vinylphenyl methylsulfonate, 4-vinylphenyl ethylsulfonate, 4-vinylphenyl n-propylsulfonate, 4-vinylphenyl isopropylsulfonate Esters, n-butylsulfonic acid-4-vinylphenyl ester, t-butylsulfonic acid-4-vinylphenyl ester, phenylsulfonic acid-4-vinylphenyl ester, methylphenylsulfonic acid-4-vinylphenyl ester, methylsulfonic acid -4-isobrobenylphenyl ester, ethylsulfonic acid-4-impropenylphenyl ester, n-propylsulfonic acid-4-isopropenylphenyl ester, isopropylsulfonic acid-4-isopropenylphenyl ester, n-butylsulfonic acid -4-isopropenylphenyl ester, t-butylsulfonic acid-4-isopropenylphenyl ester, phenylsulfonic acid-
4-isopropenylphenyl ester, methylphenylsulfonic acid-4-isopropenylphenyl ester, methyl-4-vinylphenyl carbonate, ethyl-4-
Vinylphenyl carbonate, n-propyl-4-vinylphenyl carbonate, isopropyl-4-vinylphenyl carbonate, n-butyl-4-vinylphenyl carbonate, t-butyl-4-vinylphenyl carbonate, phenyl-4-vinylphenyl carbonate,
Methylphenyl-4-vinylphenyl carbonate, methyl-4-isopropenylphenyl carbonate, ethyl-4-isopropenylphenyl carbonate, n-propyl-4-isopropenylphenyl carbonate, isopropyl-4-impropenylphenyl carbonate, n-butyl Examples include -4-isopropenylphenyl carbonate, t-butyl-4-impropenylphenyl carbonate, phenyl-4-isopropenylphenyl carbonate, methylphenyl-4-impropenylphenyl carbonate.

Further, as specific examples of the monomer providing the structural unit of formula (II), for example, styrene, 2-tetrarostyrene,
3-chlorostyrene, 4-chlorostyrene, 2.4-di-chlorostyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3
-ethylstyrene, 4-ethylstyrene, α-methylstyrene, α-ethylstyrene, α-methyl-2-chlorostyrene, α-methyl-3-chlorostyrene, α-methyl-4-chlorostyrene, and the like.

The copolymer used in the present invention may be a copolymer that further contains another monomer copolymerizable with the above monomer as a copolymer component.

Other monomers are not particularly limited as long as they are copolymerizable monomers, but specific examples include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, and acrylic acid. Examples include acrylic acid derivatives such as glycidyl, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylic acid derivatives such as glycidyl methacrylate, maleic anhydride derivatives, vinyl acetate, vinylpyridine, and acrylonitrile.

The other copolymerizable monomers mentioned above can be copolymerized within a range (usually 0 to 50 mol %) that does not impair alkali developability.

The copolymer of the present invention can be obtained by conventional polymerization methods such as radical polymerization and ionic polymerization, and the molecular weight of the copolymer is usually in the range of 1,000 to 1.000,000.

(Compound that can be acid-cleaved by irradiation with actinic rays) The compound (light generator) which can be cleaved by acid by irradiation with actinic rays used in the present invention is a substance that generates Brønsted acid or Lewis acid when irradiated with actinic rays. There are no particular limitations, and various known compounds and mixtures can be used, such as onium salts, halogenated organic compounds, halogenated organic compound/organometallic mixtures, 0-quinonediazide compounds, and the like.

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

Specific examples of halogenated organic compounds include JP-A-54-
No. 74728, JP-A-54-24113, JP-A-55
-77742, JP-A-60-3626, JP-A-60
Haloalkyl group-containing oxadiazole compounds described in No.-138539, etc.; JP-A-48-3628
No. 1, JP-A-53-133428, JP-A-54-74
No. 887, JP-A-62-175735, JP-A-63-
No. 68831, JP-A-63-70243, JP-A-63
Haloalkyl group-containing triazine compounds described in JP-A-153542, JP-A No. 63-298339, JP-A-64-35548, etc.; JP-B No. 49-21601
Haloalkyl group-containing acetophenone compounds, haloalkyl group-containing sulfoxide compounds, haloalkyl group-containing sulfone compounds, haloalkyl group-containing aliphatic hydrocarbon compounds, haloalkyl group-containing aromatic hydrocarbon compounds, haloalkyl group-containing heterologous compounds listed in the No. Examples include various compounds such as cyclic compounds and sulfenyl halide compounds.

In addition, as a halogenated organic compound, tris (β
-chloroethyl) phosphate, tris(2,3-dichloropropyl) phosphate, tris(2,3-dibromopropyl) phosphate, tris(2,3-dichloropropyl) phosphate, chlorotetrabromobutane, hexa Chlorobenzene, hexabromobenzene, hexabromocyclododecane, hexabromobiphenyl, tribromophenyl allyl ether, tetrachlorobisphenol A, tetrabromobisphenol A
, bis(bromoethyl ether)tetrabromobisphenol A, bis(chloroethyl ether)tetrachlorobisphenol A, I-lis(2,3-dibromopropyl)in cyanurate, 2,2-bis(4-hydroxy-3, Halogen-containing compounds commonly used as flame retardants such as 5-dibromophenyl)propane and 2,2-bis(4-hydroxyethoxy-3,5-dibromophenyl)propane; dichlorodiphenyltrichloroethane, benzene hexachloride, Pentachlorophenol, 2,4.6-dolichlorophenyl-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,
Generally organic compounds such as 2,2-trichloroethanol, ethyl-4,4-dichlorobenzilate, 2,4,5,4'-tetrachlorodiphenyl sulfide, 2,4,5,4'-tetrachlorodiphenyl sulfone, etc. Examples include halogen-containing compounds used as chloro-based pesticides.

Specific examples of 0-quinonediazide compounds 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, 2.1-naphthoquinonediazide-5-sulfonic acid ester, sulfonic acid ester of other quinonediazide derivatives, 1. 2-benzoquinonediazide-4=sulfonic acid chloride, l,2-naphthoquinonediazide-4
-Sulfonic acid chloride, l,2-naphthoquinonediazide-5-sulfonic acid chloride, 2.1-naphthoquinonediazide-4-sulfonic acid chloride, 2.1-naphthoquinonediazide-5-sulfonic acid chloride, sulfone of other quinonediazide derivatives Examples include acid chloride, and these may be used alone or in combination of two or more.

The compounding ratio of these compounds that can be acid-cleaved by irradiation with actinic rays is 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight, more preferably 2 to 20 parts by weight, based on 100 parts by weight of the alkali-soluble phenol resin. If the blending ratio is less than 0.1 part by weight, it is virtually impossible to form a pattern, and if it exceeds 50 parts by weight, development residues are likely to occur.

(Alkali-soluble phenolic resin) Examples of the alkali-soluble phenolic resin used in the present invention include condensation reaction products of phenols and aldehydes, condensation reaction products of phenols and ketones, vinylphenol polymers, Examples include isopropenylphenol polymers and hydrogenated products of these phenolic resins.

Specific examples of phenols used here include -valent phenols such as phenol, cresol, xylenol, ethylphenol, and phenylphenol; polyvalent phenols such as resorcinol, pyrocatechol, hydroquinone, bisphenol A, and pyrogallol. ;
Examples include.

Specific examples of aldehydes include formaldehyde, acetaldehyde, benzaldehyde, and terephthalaldehyde.

Specific examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone, and the like.

These condensation reactions can be carried out according to conventional methods.

Further, the vinylphenol-based polymer is selected from a homopolymer of vinylphenol and a copolymer of vinylphenol and a copolymerizable component.

Specific examples of copolymerizable components include acrylic acid and its derivatives, methacrylic acid and its derivatives, styrene and its derivatives, maleic anhydride, vinyl acetate, acrylonitrile, and the like.

Further, the isopropenylphenol-based polymer is selected from a homopolymer of isopropenylphenol and a copolymer of isopropenylphenol and a copolymerizable component.

Specific examples of copolymerizable components include acrylic acid and its derivatives, methacrylic acid and its derivatives, styrene and its derivatives, maleic anhydride, vinyl acetate, and acrylonitrile.

These hydrogenated products of phenolic resin can be obtained by a known hydrogenation reaction. Specifically, a phenolic resin is dissolved in a solvent, and in the presence of a homogeneous or heterogeneous hydrogenation catalyst, Produced by introducing hydrogen. Hydrogenation is usually carried out at a hydrogenation rate of 0.1 to 70
% range.

These alkali-soluble phenolic resins can be used alone, or two or more types can be used in combination.

By blending alkali-soluble phenolic resin,
Developability, storage stability, heat resistance, etc. can be improved.

The blending ratio of these alkali-soluble phenolic resins is 0 to 700 parts by weight, based on 100 parts by weight of the copolymer.
Preferably it is 0 to 300 parts by weight.

(Resist Composition) The resist composition of the present invention is usually used after being dissolved in a solvent in order to form a resist film by applying it to a substrate.

As a solvent, acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, cyclohexanol,
Ketones such as butyrolactone: Alcohols such as n-propyl alcohol, 1so-propyl alcohol, n-butyl alcohol, t-butyl alcohol; Ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dioxane; ethylene glycol monomethyl Alcohol ethers such as 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, esters such as methyl 2-oxydipropionate, ethyl 2-oxidipropionate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, monooxycarboxylic acid esters such as cellosolve acetate, methyl cellosolve acetate , ethyl cellosolve acetate, propyl cellosolve acetate, butyl cellosolve acetate, and other cellosolve esters; propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl nityl acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, and other propylene glycols ; Diethylene glycols such as diethylene glycol methyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether;
Examples include halogenated hydrocarbons such as trichloroethylene; aromatic hydrocarbons such as toluene and xylene; polar solvents such as dimethylacetamide, dimethylformamide, N-methylacetamide, and N-methylpyrrolidone; and the like. These may be used alone or in combination of two or more.

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

The resist composition of the present invention may also contain, if necessary, a copolymer of styrene and acrylic acid, methacrylic acid, or maleic anhydride to improve developability, storage stability, heat resistance, etc. Copolymers of alkenes and maleic anhydride, vinyl alcohol polymers, vinyl pyrrolidone polymers, rosin, shellac, etc. can be added.

As a developer for the resist composition of the present invention, an alkaline aqueous solution is used. Specifically, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium silicate, and ammonia; 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 hydroxide, and trimethyl Examples include quaternary ammonium salts such as hydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, and trimethylhydroxyethylammonium hydroxide.

Further, if necessary, a suitable amount of a water-soluble organic solvent such as methanol, ethanol, propatool, or ethylene glycol, a surfactant, a storage stabilizer, a resin dissolution inhibitor, etc. can be added to the aqueous alkaline solution.

The resist composition of the present invention can be applied to the surface of a substrate such as a silicon wafer by a conventional method using a solvent solution thereof, and then a resist film can be formed by drying and removing the solvent. In particular, spin coating is preferred.

Further, for exposure, a fine pattern can be formed by irradiating short wavelength ultraviolet rays or KrF excimer laser light using a deep ultraviolet irradiation device or an excimer laser device filled with krypton/fluorine gas.

By performing heat treatment (post-exposure bake) after light irradiation, the acid catalytic reaction is promoted and sensitivity can be further increased.

(The following is a blank space) [Example] The present invention will be described in more detail with reference to Examples below. In addition, parts and percentages in each example are based on weight unless otherwise specified.

100 parts of a copolymer of 4-t-butoxystyrene and α-methylstyrene (molar ratio 8:2), 4. as a light generating agent;
2 parts of 4'-di-t-butyldiphenyliodonium fluorophosphate and 0.01 part of fluorosurfactant were added to 2-
Dissolved in 400 parts of ethyl methoxypropionate, 0.1
A resist solution was prepared by filtration through a μm polytetrafluoroethylene filter.

After applying the above resist solution onto a silicon wafer using a spinner, it was baked at 85°C for 90 seconds to a thickness of 1.0 μm.
A resist film was formed. This wafer was exposed to light using a far ultraviolet irradiation device PLA-521FA and a test mask, and then developed in a tetramethylammonium hydroxide aqueous solution at 23° C. for 1 minute using the immersion method to obtain a positive pattern. .

When the patterned wafer was taken out and observed under an electron microscope, a high-contrast pattern was resolved. The patterned wafer was taken out and measured using a film thickness meter Alpha Step 200 (manufactured by Tenko Co., Ltd.), and the film thickness was 0.96 parts m.

Using the resist solution prepared in Example 1, exposure was carried out in the same manner as in Example 1. Next, 60℃ at 110℃
After second exposure, baking was performed, and development was performed using a dipping method at 23° C. for 1 minute in a tetramethylammonium hydroxide aqueous solution to obtain a positive pattern.

When the patterned wafer was taken out and observed under an electron microscope, a high-contrast pattern was resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 2
When measured at 0.00, it was 0.96 μm.

Furthermore, the patterned wafer was etched using a dry etching device DEM-451T (manufactured by Nichiden Anelva Co., Ltd.) at a power of 300 W, a pressure of 0.03 Torr, and a gas CF4.
When etching was performed at /H, = 30/10 and a frequency of 13.56 MHz, only the areas where there was no pattern were etched, and it was confirmed that the film had excellent dry etching resistance.

Shiran ■Yu 100 parts of copolymer of 4-t-butoxystyrene and α-methylstyrene (molar ratio 8:2), 2 parts of tribromomethylphenyl sulfone as a finishing agent, 0.01 part of fluorosurfactant Ethyl 2-methoxypropionate 400
Dissolved in 0.0 parts. A resist solution was prepared by filtering through a 1 μm polytetrafluoroethylene filter.

After applying the above resist solution onto a silicon wafer using a spinner, it was baked at 90°C for 90 seconds to a thickness of 1.0 μm.
A resist film was formed. Transfer this wafer to krypton/
Excimer laser device C292 filled with fluorine gas
6 (Hamamatsu Photonics 11J) and a test mask. Next, a post-exposure bake was performed at 100° C. for 60 seconds, and a positive pattern was obtained by developing with an aqueous tetramethylammonium hydroxide solution at 23° C. for 1 minute by a dipping method.

When the patterned wafer was taken out and observed under an electron microscope, a high-contrast pattern was resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 2
When measured at 0.00, it was 0.97 μm.

Fukyuto A 100 parts of copolymer of 4-t-butoxystyrene and α-methylstyrene (molar ratio 8:2), 3 parts of tris(2,3-dibromopropyl)isocyanurate as a finished generator, fluorine-based interface A resist solution was prepared by dissolving 0.01 part of the activator in 400 parts of ethyl 2-methoxypropionate and filtering through a 0.1 μm polytetrafluoroethylene filter.

After applying the above resist solution onto a silicon wafer using a spinner, it was baked at 85°C for 90 seconds to a thickness of 1.0 μm.
A resist film was formed. This wafer was exposed to light using a far ultraviolet irradiation device PLA-521FA and a test mask. Next, a post-exposure bake was performed at 100° C. for 60 seconds, and a positive pattern was obtained by developing with an aqueous tetramethylammonium hydroxide solution at 23° C. for 1 minute by a dipping method.

When the patterned wafer was taken out and observed under an electron microscope, a high-contrast pattern was resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 2
When measured at 0.00, the diameter was 0.96 μm.
A resist solution was prepared by dissolving 2 parts of t-butyl diphenyliodonium fluorophosphate and 0.01 part of a fluorosurfactant in 400 parts of ethyl 2-methoxypropionate, and filtering through a 0.1 μm polytetrafluoroethylene filter. did.

After applying the above resist solution onto a silicon wafer using a spinner, it was baked at 85°C for 90 seconds to a thickness of 1.0 part m.
A resist film was formed. This wafer was exposed to light using a far ultraviolet irradiation device PLA-521FA and a test mask. Next, a post-exposure bake was performed at 100° C. for 60 seconds, and a positive pattern was obtained by developing with an aqueous tetramethylammonium hydroxide solution at 23° C. for 1 minute by a dipping method.

When the patterned wafer was taken out and observed under an electron microscope, a high-contrast pattern was resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 2
When measured at 0.00, it was 0.97 μm.

Mitate■ Ethylsulfonic acid-4-vinylphenyl ester and α-
100 parts of methylstyrene copolymer (molar ratio 8:2),
As a finished generator, 2 parts of 4.4'-di-t-butyldiphenyliodonium fluorophosphate and 0.01 part of a fluorosurfactant were added to 40 parts of ethyl 2-methoxypropionate.
A resist solution was prepared by dissolving the resist solution in 0 parts and filtering through a 0.1 μm polytetrafluoroethylene filter.

After applying the above resist solution onto a silicon wafer using a spinner, it was baked at 90°C for 90 seconds to a thickness of 1°0 μm.
A resist film was formed. Transfer this wafer to krypton/
Excimer laser device C292 filled with fluorine gas
6 and the 0th order exposed using a test mask, 1
A post-exposure bake was performed at 10° C. for 60 seconds, and a positive pattern was obtained by developing with an aqueous tetramethylammonium hydroxide solution at 23° C. for 1 minute by dipping.

When the patterned wafer was taken out and observed under an electron microscope, a high-contrast pattern was resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 2
When measured at 0.00, it was 0.96 μm.

! 100 parts of a copolymer of t-butyl-4-vinyl carbonate and α-methylstyrene (molar ratio 8:2), 4,4'-di-t-butyldiphenyliodonium fluorophosphate as a finishing agent. 2 parts, fluorine thread surfactant o, o
Part i was dissolved in 400 parts of ethyl 2-methoxypropionate and filtered through a 0.1 μm polytetrafluoroethylene filter to prepare a resist solution.

After applying the above resist solution onto a silicon wafer using a spinner, it was baked at 90°C for 90 seconds to a thickness of 1.0 μm.
A resist film was formed. Transfer this wafer to krypton/
Excimer laser device C292 filled with fluorine gas
Exposure was performed using No. 6 and a test mask. Next, 1
A post-exposure bake was performed at 10° C. for 60 seconds, and a positive pattern was obtained by developing with an aqueous tetramethylammonium hydroxide solution at 23° C. for 1 minute by dipping.

When the patterned wafer was taken out and observed under an electron microscope, a high-contrast pattern was resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 2
When measured at 0.00, it was 0.98 μm.

100 parts of a copolymer of t-butyl-4-vinyl carbonate and α-methylstyrene (molar ratio 8:2), 3 parts of tris(2,3-dibromopropyl)in cyanurate as a finishing agent. , 0.01 part of fluorosurfactant was dissolved in 400 parts of ethyl 2-methoxypropionate, and 0.1 μm
A resist solution was prepared by filtration through a polytetrafluoroethylene filter.

After applying the above resist solution onto a silicon wafer using a spinner, it was baked at 85°C for 90 seconds to a thickness of 1.0 μm.
A resist film was formed. This wafer was exposed to light using a far ultraviolet irradiation device PLA-521FA and a test mask. Next, a post-exposure bake was performed at 110° C. for 60 seconds, and a positive pattern was obtained by developing with an aqueous tetramethylammonium hydroxide solution at 23° C. for 1 minute by a dipping method.

When the patterned wafer was taken out and observed under an electron microscope, a 0.45 μm pattern was resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 200.
When measured, it was 0.97 μm.

and 100 parts of a copolymer of 4-t-butoxystyrene and α-methylstyrene (molar ratio 8:2) in one dish, 4.
2 parts of 4'-di-t-butyldiphenyliodonium fluorophosphate, a copolymer of vinylphenol and styrene (molar ratio 7:3) as an alkali-soluble phenolic resin.
) and 0.01 part of a fluorosurfactant were dissolved in 1150 parts of ethyl 2-methoxypropionate. 1
A resist solution was prepared by filtration through a μm polytetrafluoroethylene filter.

After applying the above resist solution onto a silicon wafer using a spinner, it was betatized at 85°C for 90 seconds to a thickness of 1.0 μm.
A resist film was formed. This wafer was exposed to light using a far ultraviolet irradiation device PLA-521FA and a test mask. Next, a post-exposure bake was performed at 110° C. for 60 seconds, and a positive pattern was obtained by developing with an aqueous tetramethylammonium hydroxide solution at 23° C. for 1 minute by a dipping method.

When the patterned wafer was taken out and observed under an electron microscope, a high-contrast pattern was resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 2
When measured at 0.00, it was 0.96 μm.

(Hereinafter in the margin) [Effects of the Invention] According to the present invention, a resist composition with an excellent balance of sensitivity, resolution, etching resistance, storage stability, etc. can be obtained. The resist composition of the present invention is useful as a pattern forming material suitable for lithography using short wavelength light, and is particularly suitable as a positive resist for microfabrication of semiconductor elements.

Claims (2)

[Claims] (1) (A) General formula [I] and general formula [
II], and (B
) A resist composition containing a compound that can be acid-cleaved by irradiation with actinic rays. ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[II] (However, in the above formula, R^1 and R^3 are hydrogen atoms or alkyl groups, R^2 is an alkyl group, -S-R^6 or -C-OR^6, R^4 and R^5 are hydrogen atoms,
Halogen or an alkyl group, R^6 represents an alkyl group or an aryl group. ) (2) (A) a copolymer having structural units represented by general formula [I] and general formula [II] in the molecular chain; (B)
A compound that can be acid-cleaved by irradiation with actinic light, and (C
) A resist composition characterized by containing an alkali-soluble phenolic resin.