JPH10232492A - Manufacture of resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance precision in feeding a novolak resin and a quinonediazido derivative photosensitive agent to prepare the resist composition and to elevate the dimensional precision of the resist pattern to be obtained from this composition. SOLUTION: The photoresist composition is manufactured by preparing the organic solvent solution of the quinonediazido derivative photosensitive agent and mixing it with the novolak resin. An alkali-soluble low molecular weight phenol resin may be added to this composition and it is preferred to add to it in the form of an organic solvent solution and it is preferred to add the novolak resin in the form of an organic solvent solution.

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 positive photoresist composition mainly used for fine processing of semiconductors using near ultraviolet rays or far ultraviolet rays.

[0002]

2. Description of the Related Art It is generally known that a compound having a phenolic hydroxyl group is esterified with quinonediazide sulfonic acid, a resist film is formed from a resist composition containing the ester as a photosensitizer, and is used for fine processing of semiconductors. . That is, the composition containing the photosensitive agent having a quinonediazide group and the novolak resin is 300 to 500.
The composition is used as a positive resist by utilizing the fact that the quinonediazide group of the photosensitizer is decomposed by irradiation with light of nm to generate a carboxyl group, and the alkali-insoluble state changes to the alkali-soluble state. This positive resist is
Since it has a feature of having higher resolution than a negative resist, it is used for manufacturing various integrated circuits for semiconductors.

[0003]

A positive photoresist is usually prepared by charging a material thereof, particularly a quinonediazide-based photosensitizer, in the form of a powder. For this reason,
The material preparation accuracy (the ratio of the actual measurement value to the target or standard value of the content of each material in the resist) is about ± 0.5%, and the fluctuations in the accuracy will lead to the size of the resist pattern, etc. In some cases. Therefore,
It has been desired to solve these problems, that is, to improve dimensional accuracy and preparation accuracy.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and improve the accuracy of raw material preparation of a positive type photoresist, thereby improving the dimensional accuracy, and a resist composition suitable for manufacturing an integrated circuit. Is to manufacture.

As a result of intensive studies, the present inventors have found that in preparing a resist composition, by charging the materials in the form of a solution, it is possible to improve the accuracy of charging the materials, thereby improving the dimensional fluctuation and the like. The inventors have found that the performance can be prevented from being deteriorated, and completed the present invention.

[0006]

That is, the present invention provides a method for producing a resist composition by preparing a quinonediazide-based photosensitizer in the form of a solution of an organic solvent and mixing it with a novolak resin. It is. The positive photoresist composition may further contain an alkali-soluble low-molecular-weight phenolic additive in addition to the novolak resin and the quinonediazide-based photosensitizer, and the phenolic additive is also in the form of a solution in an organic solvent. It is preferable to prepare and prepare. The novolak resin is more preferably prepared and charged in the form of a solution of an organic solvent.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The resist composition produced according to the present invention contains a novolak resin and a quinonediazide-based photosensitizer, but the types of these components are not particularly limited, and are usually used in the resist field. be able to.

The quinonediazide-based photosensitizer is usually produced by a condensation reaction between a compound having a phenolic hydroxyl group and quinonediazide sulfonyl halide. The compound having a phenolic hydroxyl group serving as a raw material for the condensation reaction may have at least one phenolic hydroxyl group in the molecule, and particularly preferably has at least two phenolic hydroxyl groups. Examples of the compound having a phenolic hydroxyl group include compounds represented by the following formulas (I) to (IV).

[0009]

In the formula, m represents a number from 0 to 4, R ¹ , R
^{2, R 3, R 4,} R 5, R 6, R 7, R 8, R 9,
One of R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ (however, when m = 0, R ¹ , R ² , R ³ , R ⁴ , R ⁵ ,
One of R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ ) is a hydroxyl group, and the rest are each independently of the other hydrogen, hydroxyl, halogen, alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkoxy, amino , Monoalkylamino, dialkylamino, alkylcarbonylamino,
R ¹⁵ represents an alkylcarbamoyl, an arylcarbamoyl, an alkylsulfamoyl, an arylsulfamoyl, a carboxyl, a cyano, a nitro, a formyl, an alkylcarbonyl, an alkoxycarbonyl, an aryloxycarbonyl or an alkylcarbonyloxy;
R ¹⁶ , R ¹⁷ and R ¹⁸ are each independently hydrogen, a hydroxyl group,
Represents alkyl, cycloalkyl, alkenyl, aryl, aralkyl or alkoxy;

[0011]

Wherein R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R
^{26, R 27, R 28,} R 29, R 30, R 31, R 32, R 33, R 34
And one of R ³⁵ represents a hydroxyl group, and the other independently of one another, hydrogen, hydroxyl, halogen, alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkoxy,
Amino, monoalkylamino, dialkylamino, alkylcarbonylamino, alkylcarbamoyl, arylcarbamoyl, alkylsulfamoyl, arylsulfamoyl, carboxyl, cyano, nitro, formyl, alkylcarbonyl, alkoxycarbonyl, aryloxycarbonyl or alkylcarbonyloxy And R ³⁶ represents hydrogen, hydroxyl, alkyl, cycloalkyl, alkenyl, aryl, aralkyl or alkoxy;

[0013]

Wherein R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R
⁴⁶ , R ⁴⁷ , R ⁴⁸ and R ⁴⁹ independently of one another are hydrogen, hydroxyl, halogen, alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkoxy, amino, monoalkylamino, dialkylamino, alkylcarbonylamino, alkylcarbamoyl, Represents arylcarbamoyl, alkylsulfamoyl, arylsulfamoyl, carboxyl, cyano, nitro, formyl, alkylcarbonyl, alkoxycarbonyl, aryloxycarbonyl or alkylcarbonyloxy;

[0015]

Wherein R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R
Two of ⁵⁶ and R ⁵⁷ represent a hydroxyl group, and the rest independently of one another, hydrogen, hydroxyl, halogen, alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkoxy,
Amino, monoalkylamino, dialkylamino, alkylcarbonylamino, alkylcarbamoyl, arylcarbamoyl, alkylsulfamoyl, arylsulfamoyl, carboxyl, cyano, nitro, formyl, alkylcarbonyl, alkoxycarbonyl, aryloxycarbonyl or alkylcarbonyloxy the stands, one hydroxyl group of R ⁵⁸ and R ^59, the other represents hydrogen, hydroxyl or alkyl having 1 to 4 carbon atoms, R ⁶⁰
And one of R ⁶¹ represents alkyl, alkenyl, cycloalkyl or aryl; the other of R ⁶⁰ and R ⁶¹ ;
R ⁶² , R ⁶³ and R ⁶⁴ independently of one another are hydrogen, alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkoxy, amino, monoalkylamino, dialkylamino, alkylcarbonylamino, alkylcarbamoyl, arylcarbamoyl, alkylsulfa Moyl, arylsulfamoyl, carboxyl, cyano, nitro, alkylcarbonyl, alkoxycarbonyl, aryloxycarbonyl or alkylcarbonyloxy, or R ⁶⁰ and R ⁶¹ together,
And taken together R ⁶² and R ^63, together with the carbon atoms bonded thereto to form a cycloalkane ring having 5 to 8 carbon atoms.

In the above formulas (I) to (IV), the halogen may be fluorine, chlorine, bromine, iodine or the like, and the alkyl having an unspecified number of carbon atoms (alkyl such as alkylcarbonyl) And alkoxy (including alkoxycarbonyl)
Including the case where alkoxy is further bonded to another group)
The cycloalkyl can have about 1 to 10 carbon atoms, the cycloalkyl can have about 5 to 8 carbon atoms, and the alkenyl can have about 2 to 10 carbon atoms. Aryl (including the case where aryl is further bonded to another group such as arylcarbamoyl) is typically phenyl or naphthyl, which may be substituted with a hydroxyl group or an alkyl having about 1 to 4 carbon atoms. The aralkyl is typically benzyl, phenethyl, naphthylmethyl, naphthylethyl, or the like, and these aromatic rings may be substituted with a hydroxyl group or an alkyl having about 1 to 4 carbon atoms.

The compounds included in the formula (I) include, for example, the following.

4- (2,3,4-trihydroxybenzyl) phenol, 2,5- or 2,6-dimethyl-4
-(2,3,4-trihydroxybenzyl) phenol, 2,3,5- or 2,3,6-trimethyl-4-
(2,3,4-trihydroxybenzyl) phenol,
4- or 3- [1- (2,3,4-trihydroxyphenyl) -1-methylethyl] phenol, 4- or 3- [1- (2,4-dihydroxyphenyl) -1-methylethyl] phenol , 4- or 3- [1- (2,4
-Dihydroxy-3-methylphenyl) -1-methylethyl] phenol, 4- [1- (2,4-dihydroxyphenyl) -1-methylethyl] resorcinol, 4-
[1- (2,3,4-trihydroxyphenyl) -1-
Methylethyl] pyrogallol, 4- [1- (2,4-dihydroxy-5-t-butylphenyl) -1-methylethyl] phenol,

2,6-bis (2-hydroxy-5-methylbenzyl) -4-methylphenol, 2,6-bis
(4-hydroxy-3,5- or -2,5-dimethylbenzyl) -4-methylphenol, 2,6-bis (2
-Hydroxy-3,5-dimethylbenzyl) -4-methylphenol, 2,6-bis (2,4-dihydroxybenzyl) -4-methylphenol, 2,6-bis (2
3,4-trihydroxybenzyl) -4-methylphenol, 1,3-dihydroxy-4,6-bis [1- (4
-Or 3-hydroxyphenyl) -1-methylethyl] benzene, 1,3-dihydroxy-2-methyl-
4,6-bis [1- (4- or 3-hydroxyphenyl) -1-methylethyl] benzene,

4,4'-methylenebis [2- (4-hydroxybenzyl) -3,6-dimethylphenol],
4,4'-methylenebis [2- (4-hydroxy-2,
5- or -3,5-dimethylbenzyl) -3,6-dimethylphenol], 4,4'-methylenebis [2-
(2-hydroxy-5-methylbenzyl) -3,6-dimethylphenol], 2,2'-methylenebis [6- (4
-Hydroxy-3-methylbenzyl) -4-methylphenol], 4,4'-methylenebis [2- (4-hydroxy-3- or-2-methylbenzyl) -3,6-dimethylphenol], 4,4 '-Methylenebis [2-
(2,4-dihydroxybenzyl) -3,6-dimethylphenol], 4,4'-methylenebis [2- (4-hydroxy-3- or 2-methylbenzyl) -6-methylphenol], 4,4 '-Methylenebis [2- (4
-Hydroxybenzyl) -6-methylphenol],
4,4'-methylenebis [2- (2-hydroxy-5-
Methylbenzyl) -6-methylphenol], 4,4 '
-Methylenebis [2- (4-hydroxy-2,5- or -3,5-dimethylbenzyl) -6-methylphenol], 1- [1,1-bis (4-hydroxyphenyl)
Ethyl] -4- [1- (4-hydroxyphenyl) -1
-Methylethyl] benzene,

2,4-bis [2-hydroxy-3- (4
-Hydroxy-2,3,6-trimethylbenzyl) -5
-Methylbenzyl] -3,5,6-trimethylphenol, 2,6-bis [4-hydroxy-3- (4-hydroxy-3- or-2-methylbenzyl) -2,5-dimethylbenzyl] -4 -Methylphenol, 2,6-bis [4-hydroxy-3- (4-hydroxy-2,6-
Dimethylbenzyl) -2,5-dimethylbenzyl] -4
-Methylphenol, 2,6-bis [4-hydroxy-
3- (2-hydroxy-5-methylbenzyl) -2,5-
Dimethylbenzyl] -4-methylphenol, 2,6-
Bis [4-hydroxy-3- (2-hydroxybenzyl) -2,5-dimethylbenzyl] -4-methylphenol, 2,6-bis [4-hydroxy-3- (2-hydroxy-4,5-dimethyl) Benzyl) -2,5-dimethylbenzyl] -4-methylphenol, 1,4-bis [1- {4-hydroxy-3- (4-hydroxybenzyl) -5-methylphenyl} -1-methylethyl] benzene , 1,4-bis [1- {4-hydroxy-3- (2
-Hydroxy-5-methylbenzyl) phenyl} -1-
Methylethyl] benzene, 4,4'-methylenebis [2
-{4-hydroxy-3- (2,4-dihydroxybenzyl) -5-methylbenzyl} -3,6-dimethylphenol] and the like.

The compounds included in the formula (II) include, for example, the following.

4,4 ', 4 "-trihydroxytriphenylmethane, 3,4', 4" -trihydroxytriphenylmethane, 3 ", 4,4 ', 4"-tetrahydroxy-3,3',5,5'-tetramethyltriphenylmethane, 2 ", 3", 4,4 ', 4 "-pentahydroxy-
3,3 ', 5,5'-tetramethyltriphenylmethane, 2 ", 4,4'-trihydroxy-2,2', 5
5'-tetramethyltriphenylmethane, 2,2 ',
2 "-trihydroxy-4,4 ', 5,5'-tetramethyltriphenylmethane, 5,5'-di-t-butyl-
3 ", 4,4 ', 4"-tetrahydroxy-2,2'-
Dimethyltriphenylmethane, 5,5'-di-t-butyl-3 ", 4,4 ', 4" -tetrahydroxy-2,
2'-dimethoxytriphenylmethane, 5,5'-dicyclohexyl-3 ", 4,4 ', 4"-tetrahydroxy-2,2'-dimethyltriphenylmethane,5,5'-
Diisopropyl-3 ", 4,4 ', 4"-tetrahydroxy-2,2'-dimethyltriphenylmethane, 5,
5'-dicyclohexyl-3 ", 4,4 ', 4"-tetrahydroxy-2,2'-dimethoxytriphenylmethane,5,5'-diisopropyl-3",4,4',4"
-Tetrahydroxy-2,2'-dimethoxytriphenylmethane, 5,5'-dicyclohexyl-2 ", 4,4
4 ', 5 "-tetrahydroxy-2,2'-dimethyltriphenylmethane, 5,5'-diisopropyl-2",
4,4 ', 5 "-tetrahydroxy-2,2'-dimethyltriphenylmethane, 5,5'-dicyclohexyl-
2 ", 4,4 ', 5"-tetrahydroxy-2,2'-
Dimethoxytriphenylmethane, 5,5'-diisopropyl-2 ", 4,4 ', 5" -tetrahydroxy-2,
2'-dimethoxytriphenylmethane, 2 ", 4,4 '
-3 ", 4,4'- or 4,4 ', 4"-trihydroxy-3,3',5,5'-tetramethyltriphenylmethane, 4,4 ', 4 "-trihydroxy-3 "-Methoxy-3,3 ', 5,5'-tetramethyltriphenylmethane, 5,5'-dicyclohexyl-2", 4
4'-trihydroxy-2,2'-dimethyltriphenylmethane, 5,5'-diisopropyl-2 ", 4,4 '
-Trihydroxy-2,2'-dimethyltriphenylmethane, 4,4 ', 4 "-trihydroxy-3-methoxytriphenylmethane and the like.

The compounds included in the formula (III) include, for example, the following.

2,4-dihydroxybenzophenone,
2,3,4-trihydroxybenzophenone, 2,
2 ', 3-trihydroxybenzophenone, 2,2',
4-trihydroxybenzophenone, 2,2 ', 5-trihydroxybenzophenone, 2,3,3'-trihydroxybenzophenone, 2,3,4'-trihydroxybenzophenone, 2,3', 4-trihydroxybenzophenone, 2,3 ', 5-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone,
2,4 ', 5-trihydroxybenzophenone, 2',
3,4-trihydroxybenzophenone, 3,3 ', 4
-Trihydroxybenzophenone, 3,4,4'-trihydroxybenzophenone, 2,4,4'-trihydroxy-3-methylbenzophenone, 2,3,3 ', 4'
-Tetrahydroxybenzophenone, 2,3,4,4 '
-Tetrahydroxybenzophenone, 2,2 ', 4,
4'-tetrahydroxybenzophenone, 2,2 ',
3,4-tetrahydroxybenzophenone, 2,2 ',
3,4'-tetrahydroxybenzophenone, 2,
2 ', 5,5'-tetrahydroxybenzophenone,
2,3 ', 4', 5-tetrahydroxybenzophenone, 2,3 ', 5,5'-tetrahydroxybenzophenone, 2,2', 4,4'-tetrahydroxy-3
3'-dimethylbenzophenone, 2,2 ', 3,4
4'-pentahydroxybenzophenone, 2,2 ',
3,4,5'-pentahydroxybenzophenone, 2,
2 ', 3,3', 4-pentahydroxybenzophenone, 2,3,3 ', 4,5'-pentahydroxybenzophenone, 2,3,3', 4,4 ', 5'-hexahydroxybenzophenone, , 2 ', 3,3', 4,5 '
-Hexahydroxybenzophenone and the like.

The compounds included in the formula (IV) include, for example, the following.

2,4,4-trimethyl-2 ', 4', 7
-Trihydroxyflavan, 2,4,4-trimethyl-
2 ', 3', 4 ', 7,8-pentahydroxyflavan, 2,3', 4,4,8-pentamethyl-2 ',
4 ', 7-trihydroxyflavan, 4- (1',
2 ', 3', 4 ', 4'a, 9'a-hexahydro-
6'-hydroxyspiro [cyclohexane-1,9'-
Xanthene] -4'a-yl) resorcinol, 4-
(1 ', 2', 3 ', 4', 4'a, 9'a-Hexahydro-6'-hydroxy-5'-methylspiro [cyclohexane-1,9'-xanthene] -4'a-yl)- 2
-Methylresorcinol, 4- (1 ', 2', 3 ',
3'a, 9 ', 9'a-Hexahydro-6'-hydroxyspiro [cyclopentane-1,9'-cyclopenta [b]
Chromene] -3′a-yl) resorcinol and the like.

Such a compound having a phenolic hydroxyl group is esterified by a condensation reaction with quinonediazidosulfonyl halide to form a photosensitizer. The quinonediazidosulfonyl halide used here is usually o-quinonediazidosulfonyl halide, for example, 1,2-
Examples include naphthoquinonediazide-4- or -5-sulfonyl halide, and 1,2-benzoquinonediazide-4-sulfonyl halide.

This condensation reaction is generally performed in an organic solvent. Examples of the organic solvent used include water-miscible solvents such as ethers such as tetrahydrofuran and dioxane, amides such as N, N-dimethylformamide, and sulfoxides such as dimethylsulfoxide, and n-hexane and n-hexane. -Aliphatic hydrocarbons such as heptane, alicyclic hydrocarbons such as cyclohexane and cyclopentane, aromatic hydrocarbons such as toluene and xylene, and halogenated aliphatic hydrocarbons such as dichloromethane and chloroform. , Halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene, esters such as ethyl acetate, butyl acetate, and amyl acetate; ketones such as methyl isobutyl ketone and 2-heptanone;
Solvents that can be separated from water, such as glycol ether esters such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. These reaction solvents can be used alone or in combination of two or more. This condensation reaction is performed in the presence of a dehydrohalogenating agent. Examples of the dehydrohalogenating agent include aliphatic amines such as triethylamine, cyclic amines such as pyridine, and inorganic bases such as sodium hydrogen carbonate. After completion of the reaction, an excess of the dehydrohalogenating agent is usually neutralized by adding an acid such as acetic acid.

In the present invention, a quinonediazide-based photosensitive agent is prepared in the form of a solution of an organic solvent, and is mixed with a novolak resin in that state. For this purpose, the condensation reaction between the compound having a phenolic hydroxyl group and quinonediazide sulfonyl halide is carried out in an organic solvent, and the salt of the dehydrohalogenating agent formed by the reaction and the subsequent neutralization is removed to obtain a quinonediazide-based compound. A method of obtaining a sensitizer as a solution of the organic solvent, a method of adding a different organic solvent after the condensation reaction and exchanging the solvent, and obtaining a quinonediazide-based sensitizer as a solution of the organic solvent added later can be adopted.

It is desirable that the organic solvent solution of the quinonediazide-based photosensitive agent be free of metal components and halogen ions before being mixed with the novolak resin.
For this purpose, it is preferable to use a quinonediazide-based photosensitive agent as an organic solvent solution that can be separated from water, and to wash with water. Washing with water can be performed by mixing a solution of a quinonediazide-based photosensitive agent in an organic solvent with a sufficient amount of water, stirring, and then separating. If necessary, washing with an appropriate amount of water can be repeated a plurality of times. When the condensation reaction between the compound having a phenolic hydroxyl group and the quinonediazidosulfonyl halide is performed in an organic solvent that separates from water, after neutralization, the salt of the dehydrohalogenating agent is removed by filtration or the like, and then water is added. Washing is carried out by stirring. When the condensation reaction between the compound having a phenolic hydroxyl group and the quinonediazidosulfonyl halide is carried out in an organic solvent miscible with water, after neutralization, the salt of the dehydrohalogenating agent is removed by filtration or the like. An organic solvent and water that separates from water are added, and the mixture is stirred and separated, whereby a quinonediazide-based photosensitive agent is extracted into the organic solvent that separates from water, the solvent is exchanged, and washing is performed with water.

The organic solvent that dissolves the quinonediazide-based photosensitizer is preferably a solvent that becomes a solvent for the resist composition, for example, ketones and glycol ether esters that separate from water. By washing with water and liquid separation, an organic solvent solution of a quinonediazide-based photosensitizer is obtained.After that, in order to remove water contained in the solution and to obtain a concentration required for producing a resist composition, generally, Preferably, concentration is performed.

The novolak resin, which is another component of the resist composition, is usually obtained by condensing a phenolic compound and an aldehyde in the presence of an acid catalyst. Examples of the phenolic compound as a raw material of the novolak resin include o-, m- or p-cresol,
2,5-, 3,5- or 3,4-xylenol, 2,
3,5-trimethylphenol, 2-t-butyl-5-
Examples include methylphenol and t-butylhydroquinone. In addition, the aldehyde which is the other raw material of the novolak resin includes formaldehyde, acetaldehyde, aliphatic aldehydes such as glyoxal,
And aromatic aldehydes such as benzaldehyde and salicylaldehyde.

One or two of these phenolic compounds
A novolak resin is obtained by condensing at least one species with one or more aldehydes in the presence of an acid catalyst. Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, organic acids such as oxalic acid, acetic acid, and p-toluenesulfonic acid, and divalent metal salts such as zinc acetate. The condensation reaction can be performed according to a conventional method, for example, at a temperature in the range of 60 to 120 ° C. for about 2 to 30 hours. The reaction may be performed in a bulk or in a suitable solvent. The resulting novolak resin is subjected to, for example, fractionation, and the pattern of the gel permeation chromatography (GPC) (using a detector of UV 254 nm) shows that the area ratio of components having a molecular weight of 900 or less in terms of polystyrene is unreacted. It is preferably 25% or less, and more preferably 20% or less with respect to the entire pattern area excluding the pattern area of the phenolic compound.

In the present invention, it is preferable that the novolak resin is also prepared in the form of a solution of an organic solvent and mixed with the above-mentioned solution of the quinonediazide-based photosensitizer in the organic solvent. The organic solvent for dissolving the novolak resin is also preferably a solvent for the resist composition. When the novolak resin has been subjected to the above-described separation operation, the operation of solvent exchange is then performed as desired, whereby the novolak resin can be obtained as a solution of an arbitrary organic solvent.

In the present invention, an alkali-soluble low molecular weight phenolic additive having a molecular weight of 900 or less, for example, a polyhydric phenol compound having at least two phenolic hydroxyl groups in the molecule can be added to the resist composition. . When such a low molecular weight phenolic additive is blended, this additive is also prepared in the form of a solution of an organic solvent and mixed with the above-mentioned novolak resin and the quinonediazide-based sensitizer prepared in the form of an organic solvent solution. Is preferred. For example, an additive prepared in solid form can be made into a solution by dissolving it in a suitable organic solvent. The organic solvent used here is also preferably a solvent for the resist composition.

The solvent for the resist composition preferably has an appropriate drying rate and gives a uniform and smooth coating film after the solvent has evaporated. Examples of such a solvent include glycol ether esters such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate; cyclohexanone;
Ketones such as heptanone, esters such as n-amyl acetate and the like can be mentioned. These solvents can be used alone or in combination of two or more. If necessary, a small amount of a water-miscible organic solvent such as ethyl lactate or γ-butyrolactone can be contained.

The quinonediazide-based photosensitizer prepared in the form of a solution of an organic solvent is mixed with a novolak resin and, if necessary, an additional solvent and, if desired, a low-molecular-weight phenolic additive and the like. It becomes a resist composition. The resist composition thus prepared can also contain a small amount of other components as additives, such as a dye and a resin other than the novolak resin, if necessary.

In the resist composition produced according to the present invention, the composition ratio of each component is not particularly limited, and may be a value usually employed in this field. The composition ratio varies depending on the type of the quinonediazide-based photosensitizer, the presence or absence of a low-molecular-weight phenolic additive, and the like. In general, the novolak resin is 50% by weight or more based on the total solid content of the resist composition. The amount of the quinonediazide type photosensitizer is in the range of about 10 to 50% by weight, and about 3 to 40% by weight when the low molecular weight phenol type additive is used.

[0041]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The part and density display in the example are
Unless otherwise specified, it is based on weight.

Reference Example (Production of Novolak Resin) In a four-necked flask, 148.5 parts of m-cresol, 121.5 parts of p-cresol, 252 methyl isobutyl ketone
37.0 parts of a 10% aqueous oxalic acid solution and 84.8 parts of a 90% aqueous acetic acid solution, and 129.5 parts of 37.0% formalin were added dropwise over 40 minutes while heating and stirring in an oil bath at 100 ° C. The reaction was continued for another 15 hours. Next, the resultant was washed and dehydrated to obtain 466 parts of a methyl isobutyl ketone solution containing 42.3% of a novolak resin. The weight average molecular weight in terms of polystyrene measured by GPC was 4,300.

450 parts of this solution was charged into a separable flask with a bottom, and 909.6 of methyl isobutyl ketone was further added.
And 996.1 parts of n-heptane at 60 ° C.
After stirring for 0 minutes, the mixture was allowed to stand and separated. 380 parts of 2-heptanone was added to the lower layer mass obtained by liquid separation, and methyl isobutyl ketone and n-heptane were removed by an evaporator to obtain a 2-heptanone solution of a novolak resin. The weight average molecular weight in terms of polystyrene by GPC was 9,000, and the area ratio in the range of 900 or less in terms of molecular weight in terms of polystyrene was 14% with respect to the entire pattern area.

Preparation Example 1 (Production of Photosensitive Agent Solution)

[0045]

4- (1 ', 2', 3 ',
4 ', 4'a, 9'a-Hexahydro-6'-hydroxy-5'-methylspiro [cyclohexane-1,9'-
Xanthene] -4'a-yl) -2-methylresorcinol (1 mol) and 1,2-naphthoquinonediazide-5-sulfonyl chloride (2 mol) were completely dissolved in dioxane (4.72 liters), and triethylamine (2.4 mol) was added to the solution. Was added dropwise and reacted until 1,2-naphthoquinonediazide-5-sulfonyl chloride was no longer detected. After completion of the reaction, 0.6 mol of acetic acid was added and stirred for 1 hour.
The precipitate (amine salt) was filtered. The filtrate was washed by adding 6 liters of 2-heptanone and 3 liters of ion-exchanged water to remove metals and chloride ions. After liquid separation,
The 2-heptanone layer was taken out and concentrated until the solid content became about 20% to obtain a 2-heptanone solution of a photosensitive agent.

Preparation Examples 2 to 6 (Preparation of Another Photosensitive Agent Solution) Instead of the compound of the formula (a) used in Preparation Example 1, 4,4'-methylenebis [2- ( 4-
Hydroxybenzyl) -3,6-dimethylphenol]
(Formula (b): Preparation Example 2), 2,4,4-trimethyl-
2 ', 4', 7-trihydroxyflavan (the following formula (c):
Preparation Example 3), 2,3,4,4'-tetrahydroxybenzophenone (the following formula (d): Preparation Example 4), 4,4'-methylenebis [2- (2-hydroxy-5-methylbenzyl)
-3,6-dimethylphenol] (the following formula (e): Preparation Example 5) or 2,6-bis [4-hydroxy-3- (2-
Hydroxy-5-methylbenzyl) -2,5-dimethylbenzyl] -4-methylphenol (the following formula (f): Preparation Example 6) was used in the same manner as in Preparation Example 1 except that the same molar amount was used. Containing about 20% of each photosensitizer
-A heptanone solution was obtained.

[0048]

Preparation Example 7 (Preparation of Photosensitizer Solution by Another Method) The same 4- (1 ′, 2 ′, 3 ′,
4 ', 4'a, 9'a-Hexahydro-6'-hydroxy-5'-methylspiro [cyclohexane-1,9'-
Xanthen] -4'a-yl) -2-methylresorcinol (1 mol) and 1,2-naphthoquinonediazide-5-sulfonyl chloride (2 mol) are completely dissolved in 4-heptanone (4 liters), and triethylamine (2.4 mol) is added to the solution. Was added dropwise and reacted until 1,2-naphthoquinonediazide-5-sulfonyl chloride was no longer detected. After completion of the reaction, 0.6 mol of acetic acid was added and the mixture was stirred for 1 hour, and then the precipitate (amine salt) was filtered. Deionized water 3 in the filtrate
One liter was added for washing, and a treatment for removing metals and chloride ions was performed. After liquid separation, the solid content of the 2-heptanone layer was about 2%.
After concentration to 0%, a 2-heptanone solution of the same photosensitizer as obtained in Preparation Example 1 was obtained.

Preparation Examples 8 to 12 (Preparation of another photosensitive agent solution) 4- (1 ', 2', 3 ', 4', 4 'used in Preparation Example 7
a, 9'a-Hexahydro-6'-hydroxy-5'-
Instead of methylspiro [cyclohexane-1,9'-xanthene] -4'a-yl) -2-methylresorcinol, the same 4,4 'as used in Preparation Examples 2 to 6, respectively.
-Methylenebis [2- (4-hydroxybenzyl)-
3,6-dimethylphenol] (Preparation Example 8), 2,4
4-trimethyl-2 ', 4', 7-trihydroxyflavan (Preparation Example 9), 2,3,4,4'-tetrahydroxybenzophenone (Preparation Example 10), 4,4'-methylenebis [2- (2 -Hydroxy-5-methylbenzyl)-
3,6-dimethylphenol] (Preparation Example 11) or 2,6-bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -2,5-dimethylbenzyl]
Except that the same molar amount of -4-methylphenol (Preparation Example 12) was used, the same operation as in Preparation Example 7 was carried out to obtain about 20 photosensitive agents similar to those obtained in Preparation Examples 2 to 6, respectively. %
A 2-heptanone solution containing the same in concentration was obtained.

Preparation Example 13 (Comparison: Production of Powder Photosensitive Agent) The same 4- (1 ′, 2 ′, 3 ′,
4 ', 4'a, 9'a-Hexahydro-6'-hydroxy-5'-methylspiro [cyclohexane-1,9'-
Xanthene] -4'a-yl) -2-methylresorcinol (1 mol) and 1,2-naphthoquinonediazide-5-sulfonyl chloride (2 mol) are completely dissolved in dioxane (4.72 liters), and triethylamine (2.4 mol) is added to the solution. Was added dropwise and reacted until 1,2-naphthoquinonediazide-5-sulfonyl chloride was no longer detected. After completion of the reaction, 0.6 mol of acetic acid was added and the mixture was stirred for 1 hour, and then the precipitate (amine salt) was filtered. The filtrate was put into a 1% aqueous acetic acid solution, and the precipitate was filtered. This filtrate was thoroughly washed with ion-exchanged water to remove metals and chloride ions. This was dried to obtain a powdered photosensitive agent.

Preparation Examples 14 to 18 (Comparison: Production of Another Powder Photosensitive Agent) The 4- (1 ', 2', 3 ', 4',
4'a, 9'a-Hexahydro-6'-hydroxy-
In place of 5'-methylspiro [cyclohexane-1,9'-xanthen] -4'a-yl) -2-methylresorcinol, the same as used in Preparation Examples 2 to 6, respectively.
4,4'-methylenebis [2- (4-hydroxybenzyl) -3,6-dimethylphenol] (Preparation Example 14),
2,4,4-trimethyl-2 ', 4', 7-trihydroxyflavan (Preparation Example 15), 2,3,4,4'-tetrahydroxybenzophenone (Preparation Example 16), 4,4 '
-Methylenebis [2- (2-hydroxy-5-methylbenzyl) -3,6-dimethylphenol] (Preparation Example 1
7) or 2,6-bis [4-hydroxy-3- (2
-Hydroxy-5-methylbenzyl) -2,5-dimethylbenzyl] -4-methylphenol (Preparation Example 18), except that the same molar amount was used. The agent was obtained in powder form.

Preparation Example 19 (Production of phenolic additive solution) A solution containing 2.5 mol of 2,6-xylenol and 1 mol of salicylaldehyde in 400 g of methanol was charged with 0.2 mol of p-toluenesulfonic acid. Stir until no salicylaldehyde is detected. After the completion of the reaction, 200 g of ion-exchanged water was added to sufficiently precipitate crystals, followed by filtration. After the filtrate was rinsed with a 60% aqueous methanol solution, it was dissolved in 500 g of 2-heptanone and washed with ion-exchanged water to remove metal components. Next, concentration and charging of 2-heptanone were repeated so that the water content was 0.1% or less, and the concentration of the reaction product was finally adjusted to 25%. Thus, 4,4 '-(2-hydroxybenzylidene) di-2, having the structure of the following formula (g),
A solution of 6-xylenol in 2-heptanone was obtained.

[0054]

Preparation Example 20 (Preparation of another phenolic additive solution) The same procedure as in Preparation Example 19 was carried out except that the starting materials were changed to 1.2 mol of resorcinol and 1 mol of cyclohexanone, to obtain the following formula (h) 4- (1 ', 2', 3 ',
4 ', 4'a, 9'a-Hexahydro-6'-hydroxyspiro [cyclohexane-1,9'-xanthene]-
A 2-heptanone solution containing 25% of 4'a-yl) resorcinol was obtained.

[0056]

Preparation Examples 21 and 22 (Preparation of Alternative Phenolic Additive Solutions) Commercially available 1,1 having the structure of the following formula (i) or (j)
1-bis (4-hydroxyphenyl) cyclohexane (Preparation Example 21) or 9,9-bis (4-hydroxyphenyl) fluorene (Preparation Example 22) was dissolved in 2-heptanone, and the same procedure as in Preparation Example 19 was performed after washing with water. Perform the operation,
A 2-heptanone solution containing 25% of each compound was obtained.

[0058]

Preparation Example 23 (Production of Another Phenol Additive Solution) A mixed solution containing 2.1 mol of p-isopropenylphenol and 1 mol of 2-methylresorcinol in 400 g of toluene was added with 0.01% aqueous hydrochloric acid solution. And at 40 ° C 2
Stirred for hours. After the completion of the reaction, the solid was filtered, rinsed with toluene, and then dissolved in 2-heptanone. After washing with water, the same operation as in Preparation Example 19 was performed to give 4,6-bis [1- (4-hydroxyphenyl) having the structure of the following formula (k).
-1-methylethyl] -2-methylresorcinol
A 2-heptanone solution containing 5% was obtained.

[0060]

Preparation Example 24 (Preparation of Another Phenol Additive Solution) Preparation Example 24 except that the starting materials were changed to 2.1 mol of resorcinol and 1 mol of 2,2'-m-phenylenebis (2-propanol). A 2-heptanone solution containing 25% of 1,3-bis [1- (2,4-dihydroxyphenyl) -1-methylethyl] benzene having the structure of the following formula (1) by performing the same operation as in Example 23. I got

[0062]

Preparation Example 25 (Comparison: Production of Powdered Phenolic Additive) A solution containing 2.5 mol of 2,6-xylenol and 1 mol of salicylaldehyde in 400 g of methanol was added with 0.2 mol of p-toluenesulfonic acid. The mixture was charged in mole and stirred until salicylaldehyde was not detected. After the completion of the reaction, 200 g of ion-exchanged water was added to sufficiently precipitate crystals, followed by filtration. After the filtrate was rinsed with a 60% methanol aqueous solution, it was dissolved in a mixed solution of 200 g of ethyl acetate and 500 g of toluene, and washed with ion-exchanged water to remove metals. After concentrating until the concentration of ethyl acetate became 5% or less, toluene was added only by distillation to precipitate crystals sufficiently, followed by filtration. The filtrate is dried to obtain 4,4 '-(2-hydroxybenzylidene) di-2,6 having the structure of the above formula (g).
-Xylenol was obtained as a powder.

Preparation Example 26 (Comparison: Production of another powdery phenolic additive) The same procedure as in Preparation Example 25 was carried out except that the starting materials were changed to 1.2 mol of resorcinol and 1 mol of cyclohexanone, to obtain the above compound. 4- (1 ', 2', 3 ',
4 ', 4'a, 9'a-Hexahydro-6'-hydroxyspiro [cyclohexane-1,9'-xanthene]-
4'a-yl) resorcinol was obtained as a powder.

Preparation Example 27 (Comparison: Production of another powdery phenolic additive) A mixture containing 2.1 mol of p-isopropenylphenol and 1 mol of 2-methylresorcinol in 400 g of toluene was mixed with a 1% aqueous hydrochloric acid solution. 0.02 mol, and at 40 ° C 2
Stirred for hours. After the completion of the reaction, the solid was filtered and rinsed with toluene.
g of the mixture and washed with ion-exchanged water to remove metal components. After concentrating until the concentration of ethyl acetate became 5% or less, toluene was added only by distillation to precipitate crystals sufficiently, followed by filtration. The filtrate was dried to obtain 4,6-bis [1- (4-hydroxyphenyl) -1-methylethyl] -2-methylresorcinol having the structure of the above formula (k) as a powder.

Preparation 28 (Comparative: Preparation of another powdered phenolic additive) Except that the starting materials were changed to 2.1 mol of resorcinol and 1 mol of 2,2'-m-phenylenebis (2-propanol) By performing the same operation as in Preparation Example 27, 1,3-bis [1- (2,4-dihydroxyphenyl) -1-methylethyl] benzene having the structure of the above formula (1) was obtained as a powder. .

Example 4,4 'having the structure of the above formula (e) obtained in Preparation Example 5
7 parts of a solution of quinonediazidesulfonic acid ester of -methylenebis [2- (2-hydroxy-5-methylbenzyl) -3,6-dimethylphenol] in terms of solid content, the above formula (h) obtained in Preparation Example 20 4- having the structure of
(1 ′, 2 ′, 3 ′, 4 ′, 4′a, 9′a-hexahydro-6′-hydroxyspiro [cyclohexane-1,
3.1 parts of a solution of 9'-xanthen] -4'a-yl) resorcinol in terms of solid content, 1,1-bis (4-hydroxy) having the structure of the above formula (i) obtained in Preparation Example 21 A solution of phenyl) cyclohexane was converted to a solid content of 1.1.
And 2-heptanone, and then 10.13 parts of a novolak resin solution having a weight average molecular weight of 9,000 obtained in Reference Example in terms of solid content was charged and stirred. 2-Heptanone was adjusted to be 60 parts in total. After homogenization,
After microfiltration, a positive photoresist was obtained.

The above operation was repeated several times to produce a plurality of basically the same positive photoresists. Each lot was coated on a silicon wafer, dried, exposed through a predetermined mask, and developed with an alkaline developer to form a positive pattern. As a result, the positive pattern obtained from each lot has a dimension of 0.35 ±
It was within the standard of 0.015 μm. Also, the raw material charging accuracy could be kept within ± 0.15% of the target value.

In the case of various combinations using the components obtained in Preparation Examples 1 to 12 and 19 to 24, almost the same results as in the above Examples were obtained, and the effect of improvement was recognized.

Comparative Example 4 having the structure of the above formula (e) obtained in Preparation Example 17
Preparation Example 2 7 parts of quinonediazidesulfonic acid ester of 4'-methylenebis [2- (2-hydroxy-5-methylbenzyl) -3,6-dimethylphenol] (powder)
4- (1 ', having the structure of the formula (h) obtained in
2 ', 3', 4 ', 4'a, 9'a-hexahydro-
6'-hydroxyspiro [cyclohexane-1,9'-
Xanthene] -4'a-yl) resorcinol (powder)
3.1 parts, commercially available 1,1-bis (4-hydroxyphenyl) cyclohexane (powder) having the structure of the above formula (i)
Was added, and then a solution of a novolak resin having a weight average molecular weight of 9,000 obtained in Reference Example was charged and stirred with 10.13 parts in terms of solid content. 2-Heptanone was adjusted to be 60 parts in total. After homogenization, the solution was precision filtered to obtain a positive photoresist.

The above operation was repeated several times to produce a plurality of basically the same positive photoresists. Each lot was coated on a silicon wafer, dried, exposed through a predetermined mask, and developed with an alkaline developer to form a positive pattern. As a result, the positive pattern obtained from each lot has a dimension of 0.35 ±
It was distributed at 0.02 μm. Also, the accuracy of raw material preparation is
It was ± 0.5% of the target value.

[0072]

According to the present invention, it is possible to improve the accuracy of charging the raw material of the positive photoresist and the dimensional accuracy of the resist pattern formed therefrom. Therefore, the method of the present invention is particularly useful for the production of a positive photoresist requiring high accuracy, and for the formation of a resist pattern using the same.

Claims (3)

[Claims] 1. A method for producing a resist composition comprising a novolak resin and a quinonediazide-based photosensitive agent dissolved in a solvent, comprising preparing the quinonediazide-based photosensitive agent in the form of a solution of an organic solvent, And a method for producing a resist composition. 2. The resist composition further comprises an alkali-soluble low molecular weight phenolic additive, and the phenolic additive is also prepared in the form of a solution of an organic solvent and mixed with other components. The described method. 3. The method according to claim 1, wherein the novolak resin is also prepared in the form of a solution of an organic solvent.