JPH10120968A - Resin composition for resist protection film, resist protection film and pattern producing method using the film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for a resist protection film effective for suppressing PED effect and free from absorption band up to ultraviolet range having short wavelength, to provide a resist protection film made of the composition and to provide a process for producing a pattern having high dimensional accuracy in high workability. SOLUTION: This resin composition for resist protection film and the resist protection film made thereof contain a polyvinylsulfonic acid compound, a water-soluble polymer and water. The pattern-forming process comprises a step to form a resist film on a substrate, a step to expose the resist film in the form of a prescribed pattern and a step to develop the exposed resist. In the above case, a resist protection film is formed on the resist film before the exposure using the composition for resist protection film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resist protective film composition for preventing a change in sensitivity of a photosensitive resin composition used for fine processing of a semiconductor device or the like, a resist protective film, and a pattern manufacturing method using the same.

[0002]

2. Description of the Related Art In recent years, integrated circuits have been miniaturized with higher integration, and resists having excellent resolution have been demanded. Conventionally, an exposure apparatus using ultraviolet light such as g-line (436 nm) or i-line (365 nm) as an exposure light source has been used for forming an integrated circuit. In order to further increase the resolution,
Exposure using far ultraviolet rays having a shorter wavelength and exposure using X-rays or electron beams have been applied and studied. In the exposure method capable of such fine processing, the throughput of wafer processing poses a problem in terms of LSI mass production. As a method of improving the throughput, it is important to improve the sensitivity of the resist used, as well as the improvement of the apparatus, and a highly sensitive resist is required.

As resist compositions for achieving high sensitivity, for example, US Pat. No. 3,779,778, JP-B-2-27660, and JP-A-2-2585.
A chemically amplified resist described in Japanese Patent Publication No. 0 is known.
A chemically amplified resist contains a highly reactive medium under an acid catalyst and an acid precursor that generates an acid when irradiated with radiation such as ultraviolet rays and electron beams. An acid is generated in the part, and the solubility of the irradiated part and the non-irradiated part in the developing solution is changed by a reaction using the acid as a catalyst, and a pattern can be obtained in the developing step.

As a highly reactive medium used in this method, a compound or polymer having a protecting group (for example, an acetal group or a t-butoxycarbonyl group) which is decomposed (deprotected or separated) by an acid catalyst is known. I have. As the acid precursor, according to the description of the above patent document, various diazonium salts, various halogen compounds, diaryliodonium salts, onium salts such as triarylsulfonium salts, esters containing a plurality of phenolic hydroxyl groups and esters of alkyl sulfonic acids Etc. are used. These resist compositions are usually dissolved in an appropriate solvent, applied on a substrate by a spin coating method, and used for pattern formation.

[0005] Like a chemically amplified resist, a resist material utilizing an acid-catalyzed reaction as a reaction mechanism is subjected to pattern formation through processes such as formation of a resist coating film, exposure, baking after exposure, and development. In addition, the acid generated by actinic radiation is inactivated by the reaction with a compound that reacts with an acid such as an amine floating as an impurity in the air, thereby preventing the formation of a resist image or changing the sensitivity. Is known to cause. This is described, for example, in SAMacDonald et al., Proc.SPIE, 31 (1993) 1925.
It is described in. In particular, leaving between exposure and post-exposure bake has a significant adverse effect on resist properties. That is, if the standing time between the exposure and the post-exposure bake becomes long, the PED becomes unable to form a pattern due to a rapid decrease in the resist sensitivity.
The effect (PostExposure Delay effect) is well known.

As one method for reducing the PED effect, for example, a method of coating a polymer film (resist protective film) which is incompatible with a resist film described in Japanese Patent Application Laid-Open No. Hei 4-204848 on the resist film. It has been known. In this method, coating is performed to prevent amines and the like floating in the air from entering the resist film. This method has the disadvantage that the number of steps such as the application step and the removal step of the resist protective film increases, but the design is relatively easy, and it can be used with any resist if it is not compatible with the resist film. Excellent in point.

In order not to impair the properties of the resist material,
The resist protective film composition must be "transparent" to radiation such as X-rays and ultraviolet rays used in the resist process. That is, it is required that the resist protective film composition does not absorb radiation such as X-rays and ultraviolet rays and does not cause side reactions such as insolubilization. However, PE
Many of the substances used in the resist protective film composition that are considered to have the effect of suppressing the D effect do not satisfy the above conditions. For example, a material using a material having a benzene ring in its structure has strong absorption at 300 nm or less. Also,
Those that do not have a benzene ring often produce insolubles that are difficult to remove in the developing step during exposure. This is, for example, the case of H. Ban et al., J. photopolym. Sci. Technol. 7 (1
994) 17-22. As described above, a resist protective film composition that does not have absorption in the short wavelength ultraviolet (about 200 nm) and has an effect of sufficiently suppressing the PED effect has not been found so far.

[0008]

SUMMARY OF THE INVENTION Claim 1 or Claim 2
The described invention has no absorption up to short wavelength ultraviolet,
An object of the present invention is to provide a resin composition for a resist protective film having a high effect of suppressing the D effect. The third aspect of the present invention is to provide a resist protective film which does not absorb ultraviolet rays having a short wavelength and has a high effect of suppressing the PED effect. The invention according to claim 4 or 5 is to provide a method of manufacturing a pattern having excellent workability and high dimensional accuracy.

[0009]

The present invention relates to a resin composition for a resist protective film, comprising a polyvinyl sulfonic acid compound, a water-soluble polymer and water. Further, the present invention provides a resin composition for a resist protective film having a pH of 1.
The present invention relates to a resin composition for a resist protective film having a value of 0 to 3.0. Further, the present invention provides a polyvinyl sulfonic acid compound,
The present invention relates to a resist protective film containing a water-soluble polymer and water.

The present invention also relates to a method of manufacturing a pattern including a step of forming a resist film on a substrate, a step of exposing a predetermined pattern to the resist film, and a step of developing the resist after exposure. The present invention relates to a method for producing a pattern, comprising a step of forming a resist protective film on a film using the resist protective film composition. Further, the present invention relates to a method for producing a pattern in which, after the exposing step and the resist developing step, the resist protective film is removed and the heating step is performed after the exposing step.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the polyvinyl sulfonic acid compound in the present invention include polyvinyl sulfonic acid and a copolymer of vinyl sulfonic acid. Examples of the copolymerizable monomer of the vinyl sulfonic acid copolymer include acrylic acid, methacrylic acid, acrylates such as methyl acrylate, methacrylates such as methyl methacrylate, acrylamide, N-vinylacetamide, N-
And vinylpyrrolidone. The proportion of vinyl sulfonic acid in the copolymer of vinyl sulfonic acid is not particularly limited as long as the polymer is dissolved as a protective film composition to form a uniform solution, and the proportion is not less than 0.1 mol%. The vinyl sulfonic acid content is preferably at least 50 mol% in order to minimize the decrease in sensitivity due to light absorption of the copolymer. As the polyvinyl sulfonic acid-based compound, polyvinyl sulfonic acid is most preferred from the viewpoint of absorption of radiation such as ultraviolet rays and X-rays and acidity.

The water-soluble polymer in the present invention includes:
For example, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, polyethylene oxide, polyvinyl methyl ether, polyacrylamide, vinylpyrrolidone-acrylamide copolymer, vinylpyrrolidone-vinyl acetate copolymer, pullulan and the like, among which coating properties, From the viewpoint of storage stability, polyvinylpyrrolidone, vinylpyrrolidone-acrylamide copolymer and vinylpyrrolidone-vinyl acetate copolymer are preferred, and polyvinylpyrrolidone is more preferred. These water-soluble polymers are selected in a range that is not compatible with the resist film,
The molecular weight is also appropriately determined within a range that gives a uniform composition for a resist protective film and is not compatible with the resist film.

The blending amount of the polyvinyl sulfonic acid compound in the present invention is 0.001 to 0.1 with respect to the total amount of the water-soluble polymer, polyvinyl sulfonic acid compound and water.
% By weight, more preferably 0.001 to 0.05% by weight, and 0.005 to 0.03% by weight.
It is particularly preferable to set the weight%. If the amount is too small, the PED effect tends to be unable to be suppressed. If the amount is too large, the resist film tends to dissolve during the formation of the protective film. The blending amount of the water-soluble polymer in the present invention is preferably 0.1 to 10% by weight, and more preferably 0.1 to 5% by weight, based on the total amount of the water-soluble polymer, polyvinyl sulfonic acid compound and water. More preferably, it is particularly preferably 0.5 to 2% by weight. If the amount of the water-soluble polymer is too small, it tends to be repelled on the resist film and cannot be applied, and if the amount of the water-soluble polymer is too large, the flatness of the resist protective film tends to be impaired.

The pH of the aqueous solution of the resin composition for a resist protective film according to the present invention is particularly preferably from 1.0 to 3.0. If the pH of the aqueous solution is less than 1.0, the tendency of dissolving the resist film becomes strong, and if the pH is 3.0 or more, the PED effect tends to be unable to be suppressed. The pH of the aqueous solution of the resin composition for a resist protective film can be adjusted by adjusting the concentration of the polyvinyl sulfonic acid-based compound, which is an essential component of the composition. Further, the pH can be adjusted with an acidic compound or an alkaline compound. As such an acidic compound or alkaline compound, a compound which gives a uniform solution and does not impair the transparency to radiation is used, and is appropriately selected from, for example, carboxylic acids, sulfonic acids, hydrogen halides, amine compounds and the like.

In addition to the above essential components, a water-soluble surfactant such as a fluorine-based surfactant and an ether-based surfactant can be added to the resin composition for a resist protective film of the present invention. These can be obtained as commercial products, and for example, Florado FC-135 (trade name) manufactured by Sumitomo 3M Limited can be used. The amount used is preferably 0.005 to 0.05% by weight based on the total amount of the resin composition for a resist protective film of the present invention.
In the resin composition for a resist protective film of the present invention, in addition to the polyvinyl sulfonic acid-based compound and the water-soluble polymer, water and other components used as necessary
Used to be 0% by weight.

The resin composition for a resist protective film of the present invention comprises:
It is applied as an aqueous solution on a resist film, dried and used as a resist protective film. This resist protective film is transparent. Usually, the resist protective film contains about 5 to 10% by weight of water. The coating method is not particularly limited, but a spin coating method is usually used.

In the present invention, first, a chemically amplified resist film is formed on a substrate, and then a resist protective film is formed on the resist film using the resist protective film composition of the present invention. Is irradiated (exposed) with actinic radiation. A pattern can be manufactured by developing. Exposure generates an acid catalyst to cause a reaction. Therefore, it is preferable to heat to a temperature that promotes the acid catalytic reaction after exposure (post-exposure gate), and it is preferable to set the temperature to 50 to 150 ° C. Since the resist protective film of the present invention contains an acidic component, the acid component in the resist protective film diffuses into the resist film by heating, which may cause a reduction in film thickness during development. Therefore, it is preferable that the resist protective film is removed after the exposure and before the baking. The removal of the resist protective film can be easily performed by washing with water.

The above substrate is a silicon wafer, glass or the like. There are no limitations on the conditions of irradiation and development, and for example, radiation such as far ultraviolet rays such as excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams are used. At the time of development, examples of the developing solution include inorganic alkalis such as sodium hydroxide, primary amines such as ethylamine, secondary amines such as diethylamine, tertiary amines such as triethylamine, and dimethylethanolamine. And quaternary ammonium salts such as tetramethylammonium hydroxide and choline, or alkaline aqueous solutions in which cyclic amines such as piperidine are dissolved.

The formation of the resist film on the substrate can be carried out by applying the chemical amplification type resist composition on the substrate, particularly by spin coating. The above-described chemically amplified resist composition includes, for example, (a) an alkali aqueous solution-soluble resin,
A photosensitive resin composition containing (b) a compound that generates an acid upon irradiation, (c) a medium having reactivity to change the solubility in an aqueous alkali solution by an acid-catalyzed reaction, and (d) a solvent is used.

The above-mentioned alkaline aqueous solution-soluble resin is not particularly limited as long as it is a resin soluble in an alkaline aqueous solution, but a novolak resin obtained by polycondensing a phenol having at least one phenolic hydroxyl group with an aldehyde is preferable. It is. For example, phenol, o-cresol, m
-Cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol,
3,4-xylenol, 3,5-xylenol, 2,
Phenols having one phenolic hydroxyl group such as 3,5-trimethylphenol, phenols having two phenolic hydroxyl groups such as resorcinol and catechol, and phenolic hydroxyl groups such as phloroglucin, pyrogallol and hydroxyhydroquinone. Phenols. These phenols can be used alone or in combination of two or more.

The aldehydes include, for example, formaldehyde, paraformaldehyde and the like. The amount of the aldehyde used is preferably in the range of 0.5 to 1.5 mol per 1 mol of the phenol.

As a catalyst for the polycondensation, an acid catalyst capable of increasing the molecular weight is preferable. Examples of the acid catalyst include inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, and organic acids such as formic acid, oxalic acid, and acetic acid. The amount of the acid catalyst used is preferably in the range of 1 × 10 ^-5 to 1 × 10 ^-1 mol per 1 mol of phenols. The reaction temperature and reaction time of the polycondensation
The reaction temperature can be appropriately adjusted according to the reactivity of the synthesis raw materials, but usually the reaction temperature is 70 to 130 ° C., and the reaction time is 1 to 12 hours. Examples of the polycondensation method include a method in which phenols, aldehydes and a catalyst are charged at a time, and a method in which phenols and aldehydes are added in the presence of a catalyst as the reaction proceeds. After completion of the polycondensation, unreacted raw materials present in the reaction system,
To remove condensed water, catalyst, etc., under reduced pressure, for example, 2
At 0 to 50 mmHg, the temperature in the reaction system is raised to 150 to 200 ° C., and then the resin is recovered.

Examples of the compounds that generate an acid upon irradiation with radiation include onium salts, halogen-containing compounds, quinonediazide compounds, sulfonic acid ester compounds and the like. Examples of the onium salt include an iodonium salt, a sulfonium salt, a phosphonium salt, an ammonium salt, a diazonium salt and the like. Preferably, a diaryliodonium salt, a triarylsulfonium salt, a trialkylsulfonium salt (the carbon number of the alkyl group is 1-4), and the counter anion of the onium salt includes, for example, tetrafluoroboric acid, hexafluoroantimonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, and toluenesulfonic acid. Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound, and preferably include trichloromethyltriazine and bromoacetylbenzene. Examples of the quinonediazide compound include a diazobenzoquinone compound and a diazonaphthoquinone compound.

Examples of the sulfonic acid ester compound include an ester of an aromatic compound having a phenolic hydroxyl group and an alkyl sulfonic acid or an aromatic sulfonic acid. For example, as the aromatic compound having a phenolic hydroxyl group, Is phenol, resorcinol, pyrogallo-
Sulfonic acid, methanesulfonic acid, ethanesulfonic acid, propylsulfonic acid, butylsulfonic acid, and aromatic sulfonic acid such as phenylsulfonic acid and naphthylsulfonic acid. Acids and the like. An ester of an aromatic compound having a phenolic hydroxyl group with an alkylsulfonic acid can be synthesized by a usual esterification reaction. For example, an aromatic compound having a phenolic hydroxyl group can be reacted with an alkyl sulfonic acid or a chloride of an aromatic sulfonic acid under an alkaline catalyst. The synthesized product thus obtained can be purified by a recrystallization method or a reprecipitation method using an appropriate solvent.

The amount of the compound which generates an acid upon irradiation with active actinic radiation is preferably 0.5 to 30 parts by weight, more preferably 2 to 15 parts by weight, based on 100 parts by weight of the aqueous alkali soluble resin. Is preferred. If the amount of the compound that generates an acid by active actinic radiation is too large, the solubility in a solvent is reduced. If the amount is too small, sufficient sensitivity cannot be obtained.

As a medium having a reactivity that changes the solubility in an alkaline aqueous solution by the above-described acid-catalyzed reaction, there are one in which the solubility in an alkaline aqueous solution is increased and one in which the solubility is decreased by an acid-catalyzed reaction.

As a reaction mechanism for increasing the solubility in an alkaline aqueous solution, there is a mechanism in which the solubility in an alkaline aqueous solution is promoted by hydrolysis of the reactive medium by an acid-catalyzed reaction.

Examples of the reactive medium hydrolyzed by an acid-catalyzed reaction include novolak resins, acrylic resins,
Dissociates hydrogen atoms such as phenolic hydroxyl group and carboxyl group of styrene-acrylic acid copolymer, hydroxystyrene polymer, alkaline aqueous solution soluble resin such as polyvinylphenol (same as above) in the presence of acid. And a compound substituted with a group capable of being substituted.

Specific examples of the group which can be dissociated in the presence of an acid include a methoxymethyl group, a methoxyethoxymethyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a benzyloxymethyl group, a 1-methoxyethyl group, 1-ethoxyethyl group, methoxybenzyl group, t-
Butyl group, methoxycarbonyl group, ethoxycarbonyl group, t-butoxycarbonyl group, trimethylsilyl group,
Examples thereof include a triethylsilyl group and a phenyldimethylsilyl group. Among them, a tetrahydropyranyl group, a tetrahydrofuranyl group, a t-butoxycarbonyl group, a 1-ethoxyethyl group, a triethylsilyl group and the like are preferable. The substitution rate of a phenolic hydroxyl group or a carboxyl group of a group capable of dissociation in the presence of an acid with hydrogen is preferably 15 to 100%, and more preferably 30 to 100%.
It is preferably from 100% to 100%.

As a reaction mechanism for reducing the solubility in an alkaline aqueous solution, there is a mechanism in which the solubility in an alkaline aqueous solution is inhibited by polymerization or condensation reaction by an acid-catalyzed reaction in the reactive medium. As a mechanism for realizing this mechanism, for example, a crosslinking agent which is polymerized or condensed by an acid-catalyzed reaction itself or polycondensed with the above-described alkali aqueous solution-soluble resin is exemplified.

The crosslinking agent is not particularly limited as long as it is a compound having a substituent capable of performing a crosslinking reaction. Specific examples of the substituent capable of crosslinking reaction include a glycidyl ether group,
Glycidyl ester group, glycidylamino group, methoxymethyl group, ethoxymethyl group, benzyloxymethyl group, dimethylaminomethyl group, benzoyloxymethyl group, and the like. Compounds having these substituents include, for example, bisphenol A-based compounds. Epoxy compounds, bisphenol F-based epoxy compounds, nopolak-based epoxy compounds, methylol group-containing phenol compounds, alkyl ether group-containing melamine compounds, carboxymethyl group-containing melamine compounds, and the like. In this system, a cross-linking reaction of the reactive medium itself occurs due to polymerization and condensation reaction by an acid-catalyzed reaction, and the solubility in an aqueous alkaline solution is reduced.

The addition amount of a medium having a reactivity that changes the solubility in an aqueous alkali solution by an acid catalyzed reaction is selected from the viewpoints of providing a sufficient resist remaining film ratio and providing a high γ value, that is, a high resolution. Aqueous soluble resin 1
It is preferably from 3 to 300 parts by weight, more preferably from 5 to 200 parts by weight, per 100 parts by weight. If the addition amount of the medium having the reactivity to change the solubility in the alkaline aqueous solution by the acid catalyzed reaction is too large, the irradiation part may increase the solubility in the alkaline aqueous solution by the acid catalyzed reaction in the system in which the solubility is increased with respect to the developing solution. The dissolution rate tends to decrease, and the resolution tends to decrease in a system in which the irradiated part has a reduced solubility in an aqueous alkali solution due to an acid catalyzed reaction. Further, if the amount of the medium having the reactivity to change the solubility in the aqueous alkali solution by the acid catalyzed reaction is too small, the irradiated portion may increase the solubility in the aqueous alkali solution by the acid catalyzed reaction. Film loss is increased, and sensitivity tends to decrease in a system in which the irradiated portion has reduced solubility in an aqueous alkali solution due to an acid catalyzed reaction.

Examples of the solvent include glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate, diethylene glycols such as diethylene glycol monomethyl ether, and propylene glycol alkyl ether acetate such as propylene glycol methyl ether acetate. , Aromatic hydrocarbons such as toluene, ketones such as cyclohexanone, esters such as 2-hydroxypropionic acid, n-propyl acetate, isopropyl acetate, isopropenyl acetate and n-acetic acid.
Butyl, isobutyl acetate, t-butyl acetate, n-pentyl acetate, isopentyl acetate, s-pentyl acetate, t-acetic acid
-Pentyl, n-hexyl acetate, 2-hexenyl acetate,
Examples include 5-hexenyl acetate, n-heptyl acetate, 6-heptenyl acetate, and phenyl acetate having 5 to 9 carbon atoms. These solvents may be used alone or in combination of two or more.

The amount of the solvent used is preferably from 50 to 95% by weight, more preferably from 70 to 95% by weight, based on the total amount of the photosensitive resin composition containing the solvent.

A surfactant may be added to the photosensitive resin composition in order to prevent coatability, for example, striation (unevenness in film thickness) and improve developability. Examples of the surfactant include polyoxyethylene uralyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene octyl phenol ether. Commercially available products include Megafax F171 and F173 (Dainippon Ink Co., Ltd.) ) Product name), Florado FC430, FC431
(Trade name, manufactured by Sumitomo 3M Limited), and organosiloxane polymer KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.). Further, the above-mentioned photosensitive resin composition may contain, if necessary, a storage stabilizer, a dissolution inhibitor and the like.

[0036]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Synthesis Example 1 In a separable flask equipped with a stirrer, a cooling tube and a thermometer, 328.1 g of m-cresol and p-cresol 4 were added.
00.9 g, 361.2 g of 37% by weight formalin and 2.2 g of oxalic acid were charged, the separable flask was immersed in an oil bath, and polycondensation was performed for 3 hours while stirring at an internal temperature of 97 ° C. Thereafter, the internal temperature was raised to 180 ° C., and simultaneously the pressure in the reaction vessel was reduced to 10 to 20 mmHg to remove unreacted phenols, formaldehyde, water and oxalic acid.
Next, the molten resin was poured into a metal vat to collect the resin. Hereinafter, this resin is referred to as resin A.

Synthesis Example 2 Poly (p-vinylphenol) (trade name: Linker-M, Maruzen Petrochemical Co., Ltd.) was placed in a separable flask equipped with a stirrer.
20 ml) and 300 ml of ethyl acetate.
℃) to dissolve. Then, in the flask,
105 g of 4-dihydro-2H-pyran, 12N hydrochloric acid 0.1 g.
5 ml was added, and the mixture was stirred at room temperature for 1 hour.
Left for days. Next, 160 ml of a 2.38% by weight aqueous solution of tetramethylammonium hydroxide was added to the reaction solution, and the mixture was stirred well, and the organic layer was taken out. The obtained organic layer solution was washed three times with 300 ml of distilled water, and then the organic layer was dried and concentrated by an evaporator. Concentrated solution 5
Reprecipitation was performed using 500 ml of petroleum ether for 0 ml. After repeating the reprecipitation operation twice, the product was dried in a vacuum dryer (3 mmHg, 40 ° C.) for 8 hours, and poly (p-vinylphenol) in which hydroxyl hydrogen was substituted by 95% tetrahydropyranyl group. 22 g were obtained.

Synthesis Example 3 Pyrogallol (18.9 g) and pyridine (200 ml) were charged into a separable flask equipped with a stirrer, a condenser and a thermometer, and dissolved by stirring at room temperature (25 ° C.). Next, 69 g of ethanesulfonyl chloride was added to the flask at 50 ° C.
Add dropwise little by little so as not to exceed. After dropping ethanesulfonyl chloride, the mixture is stirred at room temperature for 3 hours. After the reaction,
Pour the reaction solution into 1000 ml of water and precipitate the product. After sufficiently washing the precipitate with water, the recrystallization operation was repeated twice with a mixed solvent of acetone and methanol, and the product was dried for 8 hours in a vacuum dryer (3 mmHg, 40 ° C.), and pyrogallol triethane sulfone was obtained. 10 g of the acid ester were obtained.

Synthesis Example 4 In Synthesis Example 3, 69 g of ethanesulfonyl chloride was used.
Was synthesized in the same manner as in Synthesis Example 3 except that 95 g of phenylsulfonyl chloride was used instead of As a result, pyrogallol triphenylsulfonate 12
g was obtained.

Example 1 90 g of the resin A obtained in Synthesis Example 1, 10 g of poly (p-vinylphenol) obtained by reacting a hydroxyl group with a tetrahydropyranyl group obtained in Synthesis Example 2, and pyrogallol obtained in Synthesis Example 3 1 g of ethanesulfonic acid ester of isopentyl acetate 40
After dissolving in 0 g, the solution was filtered through a membrane filter having a pore size of 0.2 μm to prepare a positive resist composition. On the other hand, poly (vinylpyrrolidone) (number average molecular weight 400,
000, 1 g of Kanto Chemical Co., Ltd.) and 2 g of 1% by weight aqueous solution of polyvinyl sulfonic acid (number average molecular weight: 50,000, measured by gel permeation chromatography and converted using a standard polystyrene calibration curve) 97
g, and filtered through a 0.5 μm filter to obtain a resin composition for a resist protective film comprising an aqueous polymer solution.
The pH of the resin composition for a resist protective film was 1.3.

The positive resist composition obtained above was spin-coated on a silicon wafer to form a 0.35-0.36 μm resist film. Next, the resin composition for a resist protective film was coated on the resist film using an automatic coating device D-SPIN636 of Dainippon Screen Mfg. Co., Ltd.
The composition was applied at a rotation speed of 0 rpm for 30 seconds and dried on a hot plate at 90 ° C. for 120 seconds to form a resist protective film. The obtained substrate is used as an electron beam lithography system H manufactured by Hitachi, Ltd.
Pattern drawing was performed using L-600. The substrate after drawing was left in the air. The standing time was 0.1 hour and 6 hours, respectively. The substrate after a predetermined standing time was washed with water for 30 seconds and spin-dried for 30 seconds. Subsequently, heating was performed at 90 ° C. for 120 seconds, followed by tetramethyl ammonium hydroxide.
Paddle development was performed for 90 seconds using a 38% by weight aqueous solution. Thereafter, the substrate was rinsed with pure water for 10 seconds and spin-dried for 30 seconds to obtain a resist pattern.

The obtained resist pattern having a size of 1.0 μm was measured using a length measuring electron microscope S-6000 manufactured by Hitachi, Ltd., and subsequently, an electron microscope S-6000 manufactured by Hitachi, Ltd. was measured.
The cross section of the pattern was observed using 500. As a result,
Within the range of 0.1 to 6 hours after drawing, the resist sensitivity and the resist cross-sectional shape do not change at all, and the resin composition for a protective film of Example 1 has an extremely excellent effect of suppressing the PED effect. I understood.

Example 2 1.0 g of pullulan (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2 g of a 1% aqueous solution of polyvinyl sulfonic acid were dissolved in 97 g of water.
The solution was filtered through a μm filter to obtain a resin composition for a resist protective film comprising an aqueous polymer solution. The pH of the resin composition for a resist protective film was 1.3. Using this resin composition for a resist protective film, a resist protective film was produced in the same manner as in Example 1, and a pattern was produced. The cross section of the obtained resist pattern having a dimension of 1.0 μm was observed in the same manner as in Example 1. As a result, the resist sensitivity and the cross-sectional shape of the resist did not change at all within the range of 0.1 to 6 hours after the drawing, and the resin composition for a resist protective film of Example 2 had an effect of suppressing the PED effect. It turned out to be very good.

Example 3 Polyvinyl methyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) 10
% Aqueous solution 10g, polyvinyl sulfonic acid 1% aqueous solution 2g
Was dissolved in 88 g of water and filtered through a 0.5 μm filter to obtain a resin composition for a resist protective film composed of an aqueous polymer solution. The pH of the resin composition for a resist protective film was 1.3.
Met. Using this resist protective film resin composition,
A resist protective film was formed in the same manner as in Example 1, and a pattern was formed. The cross section of the obtained resist pattern having a dimension of 1.0 μm was observed in the same manner as in Example 1. As a result, within the range of 0.1 to 6 hours after the drawing, the resist sensitivity and the resist sectional shape did not change at all,
It was found that the resin composition for a resist protective film of Example 3 had an extremely excellent effect of suppressing the PED effect.

Example 4 1.0 g of a vinylpyrrolidone-vinyl acetate copolymer (PVP / VAS630, trade name of GAF) and 2 g of a 1% aqueous solution of polyvinyl sulfonic acid were dissolved in 97 g of water and filtered with a 0.5 μm filter. A resin composition for a resist protective film comprising an aqueous polymer solution was obtained. PH of this resin composition for resist protective film
Was 1.3. Using this resin composition for a resist protective film, a resist protective film was produced in the same manner as in Example 1, and a pattern was produced. Obtained dimensions 1.0
The cross section of the μm resist pattern was observed in the same manner as in Example 1. As a result, the resist sensitivity and the cross-sectional shape of the resist did not change at all within the period of 0.1 to 6 hours after the drawing, and the resin composition for a resist protective film of Example 4
It was found that the effect of suppressing the ED effect was very excellent.

Example 5 Poly (vinylpyrrolidone) (number average molecular weight: 40,000)
0, manufactured by Kanto Chemical Co., Ltd.) 1 g, polyvinyl sulfonic acid 1%
0.5 g of the aqueous solution was dissolved in 98.5 g of water and filtered through a 0.5 μm filter to obtain a resin composition for a resist protective film composed of an aqueous polymer solution. The pH of the resin composition for a resist protective film was 2.6. Using this resin composition for a resist protective film, a resist protective film was produced in the same manner as in Example 1, and a pattern was produced. The cross section of the obtained resist pattern having a dimension of 1.0 μm was observed in the same manner as in Example 1. As a result, the resist sensitivity and the cross-sectional shape of the resist did not change at all in the range of 0.1 to 6 hours after the drawing, and the resin composition for a resist protective film of Example 5 had an effect of suppressing the PED effect. It turned out to be very good.

Comparative Example 1 A pattern was prepared and the cross section of the obtained resist pattern having a dimension of 1.0 μm was observed in the same manner as in Example 1 except that the resist protective film was not formed. As a result,
In order to obtain a pattern shape equivalent to that of a substrate left for 0.1 hours, a substrate left for 6 hours after drawing requires about twice the amount of electron beam irradiation as compared to a substrate left for 0.1 hour. Do you get it. That is, the PED effect could not be suppressed without a resist protective film.

[0049]

According to the first or second aspect of the present invention, the resin composition for a resist protective film does not absorb radiation such as ultraviolet rays and X-rays, and furthermore, when a chemically amplified resist substrate is left in the air after drawing. It is excellent in suppressing the PED effect and is suitable for high-precision pattern production. Claim 3
The resist protective film in (1) does not absorb radiation such as ultraviolet rays and X-rays, and is excellent in the effect of suppressing the PED effect seen when a chemically amplified resist substrate is left in the air after drawing, and produces a highly accurate pattern. It is suitable for. The method according to claim 4 or 5 is excellent in workability and can produce a highly accurate pattern.

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C09D 139/06 C09D 139/06 171/02 171/02 201/00 201/00 G03F 7/11 501 G03F 7/11 501 H01L 21/027 H01L 21/30 575 (72) Inventor: Tatsuru Hashimoto 4-13-1, Higashicho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Chemical Co., Ltd. Yamazaki Plant

Claims (5)

[Claims] 1. A resin composition for a resist protective film, comprising a polyvinyl sulfonic acid compound, a water-soluble polymer, and water. 2. The resin composition for a resist protective film according to claim 1, wherein the pH is 1.0 to 3.0. 3. A resist protective film comprising a polyvinyl sulfonic acid compound, a water-soluble polymer and water. 4. A method of manufacturing a pattern, comprising the steps of: forming a resist film on a substrate, exposing a predetermined pattern to the resist film, and developing the resist after exposure. A method for producing a pattern, comprising a step of forming a resist protective film using the composition for a resist protective film according to claim 1 or 2. 5. The method for producing a pattern according to claim 4, wherein after the step of exposing, before the step of developing the resist, a step of removing the resist protective film and a step of heating thereafter are performed.