JPH09152714A - Photosensitive resin composition and production of resist image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photosensitive resin compsn. having satisfactory sensitivity, resolution and stability as a photosensitive resin compsn. generating an acid in a patterned latent image forming part when patternwise irradiated with radiation such as UV, far UV, X-rays or electron beams, making the solubility of the irradiated part to an alkali developer different from that of the unirradiated part and forming a pattern and to provide a method for producing a resist image by which a resist pattern having satisfactory resolution can be formed. SOLUTION: This compsn. is a chemical amplification type photosensitive resin compsn. contg. a resin soluble in an aq. alkali soln., a compd. which generates an acid when irradiated with active chemical rays, a medium having such reactivity as to vary solubility to the aq. alkali soln. by a reaction with the acid as a catalyst and a solvent. This compsn. is obtd. by filtration after ripening. A coating film of the compsn. is irradiated with active chemical rays and developed to produce the objective resist image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a photosensitive resin composition and a resist image used for microfabrication of a semiconductor device or the like, and particularly to a pattern of radiation such as ultraviolet rays, far ultraviolet rays, X-rays and electron beams. -Like photosensitive resin composition that generates an acid in the pattern latent image forming part by a circular irradiation and changes the solubility of the irradiated part and the non-irradiated part in an alkali developing solution by a reaction using this acid as a catalyst to reveal a pattern. The present invention relates to a product and a method for producing a resist image using the same.

[0002]

2. Description of the Related Art In recent years, integrated circuits have become finer with higher integration, and 64M or 256M DRAM and the like have been required to form a pattern of sub-half micron or less. Therefore, a resist material having excellent resolution can be obtained. Is requested. Conventionally, a reduction projection exposure apparatus has been used for producing an integrated circuit. At present, a pattern having an exposure wavelength or less can be resolved by devising a photomask or the like. However, a resolving power sufficient to support 64M or 256M DRAM has not been obtained.

On the other hand, exposure using X-rays or electron beams can be expected to achieve finer pattern processing than exposure using light. The minimum size of the pattern depends on the beam diameter, and high resolution can be obtained. However, no matter how fine the exposure method is capable of processing, the throughput of wafer processing becomes a problem from the viewpoint of mass production of LSI. As a method for improving throughput, it is important not only to improve the apparatus but also to increase the sensitivity of the resist used.

As a resist material for achieving high sensitivity, for example, a composition containing a highly reactive medium in the presence of an acid catalyst and an acid precursor which generates an acid upon irradiation with actinic radiation is disclosed in US Pat. 3,779,778, JP-A-59-4
The compositions described in JP-A-5439 and JP-A-2-25850 are known. These known examples include compounds or polymers containing an acetal group as a highly reactive medium,
Compounds or polymers containing t-butyl groups are disclosed. Since these media contain an acid-decomposable group, they are converted into a compound or a polymer that changes the solubility in a developer by using an acid generated by irradiation with actinic radiation as a catalyst.

However, in the conventional resist material, the so-called γ value is lowered because the difference in the dissolution rate in the developing solution between the irradiated portion and the non-irradiated portion, which is necessary for obtaining a fine pattern with a good shape, becomes small. There was a problem of (decrease in resolution). When a mixture of an aqueous solution of an alkali aqueous solution and a component that reacts under an acid catalyst is used as a mixture, the heterogeneous two layers are separated, or the micro-layer separation forms a hardly soluble layer on the resist surface, resulting in a pattern shape. There was a very serious problem of getting worse. Further, the chemically amplified resist material has a problem in terms of stability such as bottle life and process stability. As described above, it is difficult for the conventional technique to achieve both high sensitivity, high resolution and stability.

[0006]

According to the first aspect of the present invention, an acid is generated in a pattern latent image forming portion by pattern-like irradiation of radiation such as ultraviolet rays, far ultraviolet rays, X-rays, and electron beams.
The acid-catalyzed reaction changes the solubility of the irradiated part and the unirradiated part in an alkali developing solution, and in a photosensitive resin composition that reveals a pattern, the photosensitive resin composition has good sensitivity, resolution, and stability. A resin composition is provided. The invention according to claim 2 provides a method of manufacturing a resist image capable of forming a resist pattern with high resolution.

[0007]

Means for Solving the Problems The present invention comprises: (a) an alkali aqueous solution-soluble resin; (b) a compound which produces an acid upon irradiation with active actinic radiation; and (c) an acid-catalyzed reaction to change the solubility in an alkali aqueous solution. The present invention relates to a chemically amplified photosensitive resin composition containing a reactive medium and a solvent (d), which is obtained by filtering after aging. The present invention also relates to a method for producing a resist image, which comprises irradiating a coating film of the photosensitive resin composition with active actinic rays and then developing the resist image.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, as the alkali aqueous solution soluble resin used, for example, novolac resin, acrylic resin, copolymer of styrene and acrylic acid, polymer of hydroxystyrene, polyvinylphenol.
And the like.

The alkali aqueous solution-soluble resin used in the present invention is not particularly limited as long as it is a resin that is soluble in an alkali aqueous solution, but phenols having one or more phenolic hydroxyl groups are used with aldehydes. Polycondensed novolac resins are preferred. For example, phenol, o-cresol, m-cresol, p-cresol, 2,3-
Xylenol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol
Phenol, such as 2,3,5-trimethylphenol
Group having one hydroxyl group, resorcinol
Examples thereof include phenols having two phenolic hydroxyl groups such as phenol and catechol, and phenols having three phenolic hydroxyl groups such as phloroglucin, pyrogallol and hydroxyhydroquinone. These phenols are
Each can be used alone or in combination of two or more. 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 the catalyst for 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 mol of the phenols. The reaction temperature and reaction time for polycondensation are
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
The temperature in the reaction system is raised to 150 to 200 ° C. at 0 to 50 mmHg, and then the resin is recovered.

Examples of the compound that produces an acid upon irradiation with active actinic radiation used in the present invention include onium salts, halogen-containing compounds, quinonediazide compounds and sulfonate compounds. As the onium salt, for example,
Iodonium salts, sulfonium salts, phosphonium salts, ammonium salts, diazonium salts and the like can be mentioned, and preferably diaryl iodonium salts, triarylsulfonium salts, trialkylsulfonium salts (wherein the alkyl group has 1 to 4 carbon atoms), 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 esters of an aromatic compound having a phenolic hydroxyl group with an alkylsulfonic acid or an aromatic sulfonic acid. For example, as an 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 synthetic product thus obtained can be purified by a recrystallization method or a reprecipitation method using an appropriate solvent.

From the viewpoint of providing sufficient sensitivity to active actinic radiation, the amount of the compound that produces an acid upon irradiation with active actinic radiation is set to 5 with respect to 100 parts by weight of the aqueous solution of alkali solution.
It is preferably from 30 to 30 parts by weight, and further from 5 to 15 parts by weight.
It is preferably in parts by weight. . 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 an acid-catalyzed reaction, there are those that have an increased solubility and a reduced solubility in an alkaline aqueous solution by the 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 the alkaline aqueous solution is promoted by hydrolysis of the above reactive medium by an acid-catalyzed reaction.

As an example of the above-mentioned reactive medium which is hydrolyzed by an acid-catalyzed reaction, a novolac resin, an acrylic resin,
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 capable of dissociating 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, and 1-ethoxy. Examples thereof include ethyl group, methoxybenzyl group, t-butyl group, methoxycarbonyl group, ethoxycarbonyl group, t-butoxycarbonyl group, trimethylsilyl group, triethylsilyl group and phenyldimethylsilyl group. Of these, a tetrahydropyranyl group, a tetrahydrofuranyl group, a t-butoxycarbonyl group, a 1-ethoxyethyl group, a triethylsilyl group and the like are preferable. The substitution ratio of the group capable of dissociating in the presence of an acid to hydrogen of the phenolic hydroxyl group or the carboxyl group is 15 to 10
It is preferably 0%, and more preferably 30 to 100%.

As a reaction mechanism in which the solubility in the alkaline aqueous solution is lowered, there is a mechanism in which the solubility in the alkaline aqueous solution is inhibited by the polymerization and the condensation reaction in the above-mentioned reactive medium by the acid catalyst reaction. 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 undergoing a crosslinking reaction. Specific examples of the crosslinkable substituent include a glycidyl ether group, a glycidyl ester group, a glycidylamino group, a methoxymethyl group, an ethoxymethyl group, a benzyloxymethyl group, a dimethylaminomethyl group, and a benzoyloxymethyl group. Examples of compounds having these substituents include bisphenol A epoxy compounds, bisphenol F epoxy compounds, nopolak epoxy compounds, methylol group-containing phenol compounds, alkyl ether group-containing melamine compounds, and carboxymethyl group-containing melamine compounds. Is mentioned. 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.

Further, the amount of the medium having the reactivity which changes the solubility in the alkaline aqueous solution by the acid-catalyzed reaction has a sufficient resist residual film ratio and a high γ value, that is, a high resolution. The amount is preferably 5 to 30 parts by weight, and more preferably 5 to 20 parts by weight, based on 100 parts by weight of the soluble resin. 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 used in the present invention include glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate, and diethylene glycol monomethyl ether. Diethylene glycols such as tellurium, propylene glycol methyl ether acetate such as propylene glycol alkyl ether acetates, aromatic hydrocarbons such as toluene, ketones such as cyclohexanone, and 2-hydroxypropionic acid such as Esters can be used. The amount of the solvent used is preferably 50 to 95% by weight, and more preferably 70 to 95% by weight, based on the photosensitive resin composition. If the amount of the solvent is too small, the solvent is not sufficiently soluble in the resist material. If the amount of the solvent is too large, a sufficient film thickness cannot be obtained when the resist film is used.

The photosensitive resin composition of the present invention has a coating property,
For example, in order to prevent striation (unevenness in film thickness) and improve developability, a surfactant can be added. As the surfactant, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, and commercially available products are Megafax F171 and F173 (Dainippon Ink and Chemicals, Inc.). Product name), Florard FC430, FC43
1 (trade name of Sumitomo 3M Ltd.), organosiloxane polymer KP341 (trade name of Shin-Etsu Chemical Co., Ltd.) and the like. Further, the photosensitive resin composition of the present invention may optionally contain a storage stabilizer, a dissolution inhibitor, and the like.

The step of preparing the chemically amplified photosensitive resin composition usually has a resin that is soluble in an aqueous alkali solution, a compound that produces an acid upon irradiation with actinic radiation, and a reactivity that changes the solubility in an aqueous alkali solution through an acid-catalyzed reaction. Charge the medium and other additives and solvents to the synthesis kettle. Then
The composition is dispersed and dispersed in a solvent by mixing, stirring, heating, ultrasonic exposure, etc., and the chemically amplified photosensitive resin composition is made into a uniform solution, and then filtered using a membrane filter, cartridge filter, etc. Then, the fine particles present in the chemically amplified photosensitive resin composition are removed, and then the bottle is filled with a canister or the like. In the present invention, the composition is diffused and dispersed in a solvent, and after confirming that it is dissolved and in a uniform state by visual observation or the like, in order to sufficiently react or associate the unstable factor existing in the solution, ,further,
Aging such as heating, stirring, and leaving.

The aging method is not particularly limited as long as it is a method of sufficiently reacting or associating the unstable factor existing in the solution. Heating, for the chemically amplified photosensitive resin composition confirmed to be dissolved and in a uniform state,
For example, it is preferably performed at a temperature of 30 to 70 ° C. In addition, stirring can be performed to promote the reaction or association of the unstable factor. When the unstable factor influences not only the generation of fine particles but also the sensitivity and the resolution, it is preferable not to perform heating but to leave it at a low temperature of 0 to 30 ° C., for example. As the aging method, at least one of heating, stirring and leaving can be adopted, and these can be appropriately combined.

As described above, the aging method is adopted in consideration of the reactivity of the compound used to generate an acid upon irradiation with active actinic radiation and the medium having a reactivity that changes the solubility in an alkaline aqueous solution by an acid-catalyzed reaction. be able to. In addition, the aging time is preferably a time when a sufficiently unstable factor can be reacted or associated. In that case, it is preferable to select the aging time by an aging method such as heating, stirring, and leaving, and for example, the aging time is preferably 1 to 240 hours.

With the photosensitive resin composition of the present invention, a resist image is produced by forming a resist film on a substrate such as a wafer or glass and irradiating with active actinic rays and developing. As the method, a conventionally well-known method can be adopted. There are no particular restrictions on the conditions of irradiation with actinic radiation and development. For example, radiation such as far ultraviolet rays such as excimer lasers, X-rays such as synchrotron radiation, and charged particle beams such as electron beams are used.

Examples of the developer for the photosensitive resin composition of the present invention include inorganic alkalis such as sodium hydroxide, primary amines such as ethylamine, secondary amines such as diethylamine, and secondary amines such as triethylamine. Tertiary amines,
Alkaline aqueous solutions in which alcohol amines such as dimethylethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide and choline, or cyclic amines such as piperidine are dissolved are used.

[0026]

[Function] A chemically amplified resist material utilizing an acid-catalyzed reaction contains a naphthoquinonediazide-based photosensitizer and an alkali-soluble resin because it contains a medium that reacts with a small amount of acid and a compound that generates an acid with a small amount of energy. It is considered that the bottle life is worse than that of the resist material containing the main component. In particular, in a chemically amplified resist material, a gel-like substance that reacts with or associates in the resist material due to the above-mentioned highly reactive and unstable factors and is generated in a bottle filled with the resist material. There is a problem that the number of fine particles in the liquid increases. In order to prevent them, it is possible to remove impurities such as acids and alkalis that are present in trace amounts in the resist material, but the impurities that are taken into the matrix or attached to the reactive functional groups are added to the bottle life. It is difficult to remove until it has no effect. Further, from an industrial point of view, it is not practical because it requires a high cost for refining the material. The present inventors have found that in the process of preparing a chemically amplified photosensitive resin composition, the composition is dissolved in a solvent and then filtered, and then aging such as heating, stirring, and leaving is carried out, so that the resist material may not be contained in the resist material. By sufficiently reacting or associating stably existing factors and then removing them by filtration, an increase in the number of fine particles in the liquid in the bottle filled with the resist material can be suppressed,
The bottle life can be improved.

[0027]

The present invention will be described below with reference to examples. Synthesis Example 1 m-cresol 328.1 g and p-cresol 4 were placed in a separable flask equipped with a stirrer, a condenser and a thermometer.
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 95% of the hydroxyl groups in the polymer were replaced with tetrahydropyranyl groups to replace the hydrogen. 22 g of (p-vinylphenol) was obtained.

Synthesis Example 3 Silver trifluoromethanesulfonate (25 g) was dissolved in tetrahydrofuran (200 ml), and trimethylsulfonium iodide (20 g) was added thereto and the mixture was stirred. After reacting at room temperature for about 1 day, the precipitated silver iodide is removed by filtration. The filtrate was concentrated, and the obtained crude product was recrystallized using ethyl alcohol to obtain 17 g of trimethylsulfoniotrifluoromethanesulfonate.

Example 1 In a separable flask equipped with a stirrer, 92 g of Resin A obtained in Synthesis Example 1 and poly (p-vinylphenol) 8 having the hydroxyl group obtained in Synthesis Example 2 protected with a tetrahydropyranyl group 8
g, 5 g of trimethylsulfoniotrifluoromethanesulfonate obtained in Synthesis Example 3 as a compound which generates an acid upon irradiation with actinic radiation, and methylcellosolve acetate 300.
After visually confirming that g was charged and dissolved to form a uniform solution, the solution was immersed in a water bath at 40 ° C. and stirred for 30 hours. Then, the solution was filtered through a membrane filter having a pore size of 0.1 μm to prepare a resist solution. 0.3 of the obtained resist solution
The number of fine particles in liquid having a diameter of μm or more was measured using a fine particle number measuring device KL-20 manufactured by Rion Co., Ltd.
/ ml.

The obtained resist solution was applied on a silicon wafer and heat-treated at 120 ° C. for 10 minutes to obtain a resist film having a thickness of 1.0 μm. An electron beam writer with an acceleration voltage of 50 kV was used to draw a hole pattern on the resist at a dose of 3.5 μC / cm ² and then heat treated at 100 ° C. for 10 minutes to remove the latent image portion of the resist. It promoted a reaction that increased the solubility in aqueous alkaline solutions. After this heat treatment, 2.38% by weight of tetramethylammonium hydroxide
The resist film on which a latent image was formed was developed for 120 seconds using an aqueous solution to obtain a positive resist pattern. 0.4 μm
As a result of observing the cross-sectional shape of the hole pattern of No. 1 with an electron microscope, the resist pattern was rectangular and good. The amount of film reduction after development was 0.02 μm, which was good. After this resist solution was stored at room temperature for 90 days, the number of fine particles in a liquid having a diameter of 0.3 μm or more was measured by the same method as above, it was 20 particles / ml, and no increase in the number of fine particles was observed. Bottle life was good.

Example 2 In Example 1, instead of 5 g of trimethylsulfoniotrifluoromethanesulfonate as a compound which produces an acid upon irradiation with active actinic radiation, a trisubstituted ester of pyrogallol and methanesulfonic acid (Midori Chem. Strain), trade name Pyrogallol trimesylate) 2 g
A resist was prepared in the same manner as in. The number of fine particles in the liquid having a diameter of 0.3 μm or more of the obtained resist solution was measured using a liquid fine particle number measuring device KL-20 manufactured by Rion Co., Ltd., and it was 15 particles / ml. Further, a resist pattern was formed in the same manner as in Example 1, and a 0.4 μm thick hole was formed.
As a result of observing the cross-sectional shape of the leu pattern with an electron microscope, the resist pattern was rectangular and good. The amount of film reduction after development was 0.02 μm, which was good. After storing this resist solution at room temperature for 90 days, 0.3 μm
When the number of fine particles in the liquid having a diameter or more was measured by the same method as above, it was 15 particles / ml, and no increase in the number of fine particles was observed.
Bottle life was good.

Example 3 In a separable flask equipped with a stirrer, 100 g of Resin A obtained in Synthesis Example 1 and 1-hydroxy-4-bromo-2 were used.
25 g of bromoacetylnaphthalene, 15 g of amino resin (Cymel 303, manufactured by Mitsui Cyanamid Co., Ltd.) and propylene glycol monomethyl ether acetate 40
After 0 g was charged and it was visually confirmed that the solution was dissolved to form a uniform solution, the solution was allowed to stand at room temperature for 200 hours. Then, the solution was filtered through a membrane filter having a pore size of 0.1 μm to prepare a resist solution. The number of fine particles in the liquid having a diameter of 0.3 μm or more of the obtained resist solution was measured using a liquid fine particle number measuring device KL-20 manufactured by Rion Co., Ltd., and it was 50 particles / ml.

The resulting resist solution was applied onto a silicon wafer and heat-treated at 100 ° C. for 10 minutes to obtain a resist film having a thickness of 1.0 μm. After drawing a line & space pattern on the resist with an irradiation amount of 7.0 μC / cm ² using an electron beam drawing device with an acceleration voltage of 50 kV on this substrate, 90
Heat treatment was performed at 10 ° C. for 10 minutes to accelerate the reaction of decreasing the solubility of the latent image portion of the resist in the aqueous alkaline solution. After this heat treatment, 2.
The resist film on which a latent image was formed was developed for 300 seconds using a 38% by weight aqueous solution to obtain a negative resist pattern.
As a result of observing the cross-sectional shape of the 0.4 μm line & space pattern with an electron microscope, the resist pattern was rectangular and good. The amount of film loss after development was 0.05 μm, which was favorable. This resist solution is used at room temperature for 90
After storage for a day, the number of fine particles in liquid having a diameter of 0.3 μm or more was measured by the same method as above, and it was 50 particles / ml. No increase in the number of fine particles was observed and the bottle life was good.

Comparative Example 1 A positive resist was prepared in the same manner as in Example 1 except that filtration was carried out immediately after confirming that the solution was dissolved and became a uniform solution in Example 1. The number of fine particles in the liquid having a diameter of 0.3 μm or more of the obtained resist solution was measured using a liquid fine particle number measuring device KL-20 manufactured by Rion Co., Ltd., and it was 20 particles / ml. Further, the obtained resist solution was applied onto a silicon wafer and heat-treated at 120 ° C. for 10 minutes to obtain a resist film having a film thickness of 1.0 μm. Using an electron beam drawing device with an acceleration voltage of 50 kV on this substrate, 3.5
After drawing the hole pattern on the resist with a dose of μC / cm ² ,
A heat treatment was performed at 100 ° C. for 10 minutes to accelerate the reaction of increasing the solubility of the latent image portion of the resist in the alkaline aqueous solution. After this heat treatment, the resist film on which the latent image was formed was developed for 120 seconds using a 2.38 wt% aqueous solution of tetramethylammonium hydroxide to obtain a positive resist pattern. As a result of observing the cross-sectional shape of the hole pattern of 0.4 μm with an electron microscope, the resist pattern was rectangular and good. The amount of film loss after development is 0.02 μm,
It was good. However, this resist solution was added at room temperature to 1
After storing for 0 days, the number of fine particles in the liquid having a diameter of 0.3 μm or more was measured by the same method as above, and it was 8,000 particles / ml, and an increase in the number of fine particles was observed, and the bottle life was unstable. .

Comparative Example 2 A positive type resist was prepared in the same manner as in Example 1 except that filtration was carried out immediately after it was confirmed that the solution was dissolved and became a uniform solution in Example 3. The number of fine particles in the liquid having a diameter of 0.3 μm or more of the obtained resist solution was measured using a liquid fine particle number measuring device KL-20 manufactured by Rion Co., Ltd., and it was 50 particles / ml. Further, the obtained resist solution was applied onto a silicon wafer and heat-treated at 100 ° C. for 10 minutes to obtain a resist film having a film thickness of 1.0 μm. An electron beam drawing device with an acceleration voltage of 50 kV was used on this substrate to obtain 7.0
After the hole pattern was drawn on the resist with a dose of μC / cm ^2, the resist was heat treated at 90 ° C. for 10 minutes to promote the reaction of decreasing the solubility of the latent image portion of the resist in the alkaline aqueous solution. After this heat treatment, the resist film on which the latent image was formed was developed for 300 seconds using a 2.38 wt% aqueous solution of tetramethylammonium hydroxide to obtain a negative resist pattern. As a result of observing the cross-sectional shape of the 0.4 μm line & space pattern with an electron microscope, the resist pattern was rectangular and was good. The amount of film loss after development is 0.
It was 05 μm, which was good. After this resist solution was stored at room temperature for 10 days, the number of fine particles in the liquid having a diameter of 0.3 μm or more was measured by the same method as above.
The number of fine particles was increased, and the bottle life was unstable.

[0037]

The photosensitive resin composition according to claim 1 is
An acid is generated in the pattern image forming part by pattern irradiation of radiation such as ultraviolet rays, far ultraviolet rays, X-rays, electron beams, etc., and by the reaction using the acid as a catalyst, the alkali developing solution for the irradiated part and the unirradiated part A photosensitive resin composition that changes the solubility and reveals a pattern has good sensitivity, resolution, and storage stability. By the method of manufacturing a resist image according to the second aspect, a resist pattern with high resolution can be formed.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical indication location H01L 21/027 H01L 21/30 502R 569F (72) Inventor Michiaki Hashimoto 4 Higashimachi, Ibaraki Prefecture No. 13-1 Hitachi Chemical Co., Ltd. Yamazaki Factory

Claims (2)

[Claims] 1. An (a) aqueous solution of an alkali aqueous solution, (b) a compound which produces an acid upon irradiation with active actinic radiation, (c) a medium having a reactivity to change the solubility in an aqueous alkali solution by an acid-catalyzed reaction, and (d) ) A chemically amplified photosensitive resin composition containing a solvent, which is obtained by filtering after aging. 2. A method for producing a resist image, which comprises irradiating a coating film of the photosensitive resin composition according to claim 1 with active actinic rays and then developing the resist image.