JP2799610B2 - Radiation-sensitive resin composition - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a radiation-sensitive resin composition containing an alkali-soluble resin, and more particularly, to ultraviolet rays, X-rays, electron beams, molecular beams, γ-rays, and synchrotron radiation. The present invention relates to a radiation-sensitive resin composition which is sensitive to radiation such as tron radiation and proton beam, and is particularly suitable as a resist for producing an integrated circuit.

[Conventional technology]

2. Description of the Related Art A radiation-sensitive resin composition mainly containing an alkali-soluble resin, a radiation-sensitive compound and a solvent is widely used in the production of integrated circuits because a high-resolution resist pattern can be obtained. For example, the radiation-sensitive resin composition is formed on a wafer by applying the radiation-sensitive resin composition, evaporating a solvent to form a radiation-sensitive resin layer on the wafer, partially irradiating the radiation, and developing with a developer. It is done by doing.

(Problems to be Solved by the Invention) However, when a pattern is formed on a wafer using these radiation-sensitive resin compositions, a part of the pattern is peeled off, and a desired resist pattern cannot be formed. May occur. Particularly, in recent years, the size of a pattern to be formed has become smaller, and peeling of a fine pattern has become an important problem.

Therefore, an object of the present invention is to provide a radiation-sensitive resin composition that effectively avoids pattern peeling during pattern formation and is suitable for forming a resist layer.

(Means for Solving the Problems) The present invention has succeeded in achieving the above object by adjusting the content of the acid component to a certain value or less.

That is, according to the present invention, an alkali-soluble resin,
A radiation-sensitive resin composition containing a quinonediazide compound and a solvent, wherein the content of the acid component is adjusted to a range of 1.0 × 10 ⁻³ meq / g or less. Is provided.

Examples of the radiation-sensitive resin composition of the present invention include a composition mainly composed of an alkali-soluble resin, a 1,2-quinonediazide compound and a solvent.

Alkali-soluble resin As the alkali-soluble resin used in the present invention, for example, an alkali-soluble novolak resin (hereinafter, simply referred to as “novolak resin”) can be suitably used. This novolak resin is obtained by polycondensing phenols and aldehydes in the presence of an acid catalyst.

Phenols; Examples of such phenols include phenol,
o-cresol, m-cresol, p-cresol, o
-Ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol, 2,3-xylenol,
2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, p-phenylphenol, hydroquinone, catechol, resorcinol, 2-methylresorcinol, pyrogallol , Α-naphthol, bisphenol A, dihydroxybenzoic acid ester, gallic acid ester and the like. Among these phenols, phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol, 2,3,5-
Trimethylphenol, resorcinol, 2-methylresorcinol and bisphenol A are preferred. These phenols are used alone or in combination of two or more.

Aldehydes; As aldehydes to be polycondensed with phenols,
For example, formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-chlorobenzaldehyde, m- Chlorobenzaldehyde, p-
Chlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde and the like are used. Of these aldehydes, formaldehyde, acetaldehyde and benzaldehyde are preferred. These aldehydes can be used alone or in combination of two or more.

Aldehydes are used in an amount of 0.7 mole per mole of phenols.
３3 mol is preferred, more preferably 0.75-1.3 mol.

Acid catalysts: Acid catalysts used for polycondensation include hydrochloric acid, nitric acid, sulfuric acid,
Formic acid, oxalic acid, acetic acid and the like can be mentioned. The amount of these acid catalysts used is usually based on 1 mole of phenols.
It is 1 × 10 ^{-4 to} 5 × 10 ^-1 mol.

Polycondensation reaction: In the polycondensation, water is usually used as a reaction medium. However, when the phenol used for the polycondensation does not dissolve in the aqueous solution of the aldehyde and becomes a heterogeneous system from the beginning of the reaction, the reaction medium is used. May be used as a hydrophilic solvent. These hydrophilic solvents include, for example, methanol,
Examples include alcohols such as ethanol, propanol and butanol, and cyclic ethers such as tetrahydrofuran and dioxane. The amount of the reaction medium to be used is usually 20 to 1000 parts by weight per 100 parts by weight of the reaction raw material.

The temperature of the polycondensation can be appropriately adjusted according to the reactivity of the reaction raw materials, but is usually 10 to 200 ° C., preferably 7 to 200 ° C.
0-150 ° C.

After completion of the polycondensation, the unreacted raw materials, the acid catalyst and the reaction medium present in the system are removed, and the novolak resin is recovered.

The novolak resin obtained above was dissolved in a solvent such as ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, or ethyl 2-hydroxypropionate, and after adding a water-soluble alcohol and water to the resin solution and mixing, By separating the aqueous solution into a layer and an aqueous solution layer, a part of the low nuclei can be removed to the aqueous solution layer to adjust the molecular weight. The novolak resin from which some low nuclei have been removed is recovered by collecting the resin layer and heating it under reduced pressure to remove water and the like.

The polystyrene-equivalent weight average molecular weight of the novolak resin used in the present invention is usually from 2,000 to 2,500, preferably from 3,500 to 20,000. If the average molecular weight is less than 2,000, the pattern shape, resolution and developability tend to deteriorate. If it exceeds 25,000, the pattern shape and developability tend to deteriorate, and the sensitivity tends to decrease.

1,2-quinonediazide compound As the 1,2-quinonediazide compound used in the present invention, 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2 -Naphthoquinonediazide-5-sulfonic acid ester.

Specifically, 1,2-(poly) hydroxybenzene such as p-cresol, resorcinol, pyrogallol, phloroglicinol, etc.
Benzoquinonediazide-4-sulfonic acid ester, 1,2
-Naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester; 2,4-dihydroxyphenylpropyl ketone, 2,4-dihydroxyphenyl-n-hexyl ketone, 2,4-dihydroxybenzophenone 2,3,4-trihydroxyphenyl-n-hexyl ketone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2 ,
3,4,2'-tetrahydroxybenzophenone, 2,2 ', 4,
4'-tetrahydroxybenzophenone, 2,2 ', 3,4,6'
-Pentahydroxybenzophenone, 2,3,3 ', 4,4',
5'-hexahydroxybenzophenone, 2,3 ', 4,4',
(Poly) such as 5 ', 6-hexahydroxybenzophenone
1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid of hydroxyphenylalkylketone or (poly) hydroxyphenylarylketone Ester; bis (p-hydroxyphenyl) methane, bis (2,4
-Dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2,2-bis (p-hydroxyphenyl) propane, 2,2-bis (2,4-dihydroxyphenyl) propane, 1,2-benzoquinonediazide-4 of bis [(poly) hydroxyphenyl] alkane such as 2-bis (2,3,4-trihydroxyphenyl) propane
-Sulfonic acid ester, 1,2-naphthoquinonediazide-
4-sulfonic acid ester or 1,2-naphthoquinonediazido-5-sulfonic acid ester; lauryl 3,5-dihydroxybenzoate, phenyl 2,3,4-trihydroxybenzoate, 3,4,5-trihydroxybenzoic acid 1,2- (1) -alkyl (poly) hydroxybenzoate or aryl (poly) hydroxybenzoate such as lauryl, propyl 3,4,5-trihydroxybenzoate and phenyl 3,4,5-trihydroxybenzoate
Benzoquinonediazide-4-sulfonic acid ester, 1,2
-Naphthoquinone azide-4-sulfonic acid ester or
1,2-naphthoquinonediazide-5-sulfonic acid ester; bis (2,5-dihydroxybenzoyl) methane, bis (2,3,4-trihydroxybenzoyl) methane, bis (2,4,6-trihydroxybenzoyl) Methane, p-bis (2,5-dihydroxybenzoyl) benzene, p-bis (2,3,4-trihydroxybenzoyl) benzene, p
1,2-benzoquinonediazido-4-sulfonic acid ester of bis [(poly) hydroxybenzoyl) alkane or bis [(poly) hydroxybenzoyl) benzene such as bis (2,4,6-trihydroxybenzoyl) benzene, 1 1,2-naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester; ethylene glycol-di (3,5-dihydroxybenzoate), polyethylene glycol-di (3,5-dihydroxybenzoate) 1,2-benzoquinonediazide-4-sulfonic acid ester of polyethylene glycol-di [(poly) hydroxybenzoate], such as polyethylene glycol-di (3,4,5-trihydroxybenzoate), 1,2-naphthoquinonediazide- 4-sulfonic acid ester or 1,2-naphthoquino Diazide-5-sulfonic acid ester; and the like can be exemplified. The applicant's Japanese Patent Application Laid-Open
The 1,2-quinonediazide compounds described in JP-A-144463 and JP-A-1-156738 can also be used.

Of the 1,2-quinonediazide compounds, especially 2,3,4-
1,2-naphthoquinonediazide-4-sulfonic acid ester of trihydroxybenzophenone or 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfone of 2,4,6-trihydroxybenzophenone 1,2-naphthoquinonediazidosulfonic acid esters of trihydroxybenzophenone such as acid esters or 1,2-naphthoquinonediazide-5-sulfonic acid esters; 1,2 of 2,2 ', 4,4'-tetrahydroxybenzophenone
-Naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,2 of 2,3,4,4'-tetrahydroxybenzophenone
-Naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,2 of 2,3,4,2'-tetrahydroxybenzophenone
-Naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,2-naphthoquinonediazide-4-of 3'-methoxy-2,3,4,4'-tetrahydroxybenzophenone Sulfonate or 1,2-naphthoquinonediazide-5
-1,2-naphthoquinonediazidosulfonic acid esters of tetrahydroxybenzophenone such as sulfonic acid esters.

These 1,2-quinonediazide compounds are used alone or in combination of two or more. The 1,2-quinonediazide compound is a novolak resin of 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester. As described above, a part or the whole thereof may react with the alkali-soluble resin to form a condensate.

The content of the 1,2-naphthoquinonediazide group in the 1,2-quinonediazide compound used in the present invention is usually 4
The number (condensation ratio) of 1,2-naphthoquinonediazidosulfonic acid groups ester-bonded to trihydroxybenzophenone or tetrahydroxybenzophenone is 0 to 90% by weight.
1.5 to 3 on average for naphthoquinonediazidesulfonic acid ester and 2 on average for tetrahydroxybenzophenone / 1,2-naphthoquinonediazidesulfonic acid ester.
To 4 are preferable.

The amount of the 1,2-quinonediazide compound is usually 5 to 100 parts by weight based on 100 parts by weight of the alkali-soluble resin.
Parts by weight, preferably 10 to 50 parts by weight. If the amount is too small, patterning is difficult. On the other hand, if the amount is too large, development with a developer composed of an alkaline aqueous solution may be difficult.

Solvents Solvents used in the present invention include, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, benzyl ethyl ether, ethers such as dihexyl ether, methylcellol acetate propylene glycol monomethyl Ether acetate, ethyl acetate,
Esters such as butyl acetate, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, ethylene carbonate, propylene carbonate, γ-butyrolactone, ethyl 2-oxypropionate, methyl ethyl ketone, cyclohexanone, diisobutyl ketone, acetonylacetone, Examples include ketones such as isophorone, fatty acids such as caproic acid and caprylic acid, alcohols such as 1-octanol, 1-nonanol and benzyl alcohol, and aromatic hydrocarbons such as toluene and xylene. These solvents are used alone or in combination of two or more.

Such a solvent is preferably used in such an amount that the solid content concentration is in the range of 5 to 50% by weight.

Various Compounding Agents In the present invention, various compounding agents such as storage stabilizers, sensitizers, and surfactants can be compounded.

Examples of storage stabilizers include p-phenylphenol, 4,4'-dihydroxydiphenyl, 2,5-di-t-amylhydroquinone, 4,4'-dihydroxydiphenylcyclohexane, 2,2'-methylenebis (4-methyl -6
-T-butylphenol), 2,6-di-t-butyl-p
A phenolic antioxidant such as -cresol, 4,4'-butylidene-bis (6-t-butyl-m-cresol);
Triethanolamine, triethylamine, tributylamine, ethylenediamine, tetramethylethylenediamine, butylamine, tripropylamine, monoethanolamine, cetylamine, dodecyldimethylamine,
Diethanolamine, benzylamine, morpholine,
Nitrogen-containing compounds such as N-ethylmorpholine and piperidine; 2,4-bis (n-octylthio) -6- (4-hydroxy-3,5-t-butylanilide) -1,3,5-triazine and the like And various sulfur-containing antioxidants.

The amount of these storage stabilizers is, for example, in the phenolic antioxidant and the sulfur-containing antioxidant,
10 parts by weight or less based on 100 parts by weight of the alkali-soluble resin, and in the nitrogen-containing compound, the alkali-soluble resin 10
It is preferably 5 parts by weight or less based on 0 parts by weight.

The sensitizer is compounded to improve the sensitivity of the resist. As such a sensitizer, for example, 2H-pyrido- (3,2-b) -1,4-oxazine-3 (Four
H) -ones, 10H-pyrido- (3,2-b)-(1,4) -benzothiazines, urazoles, hydantoins, parbituric acids, glycine anhydrides, 1-hydroxybenzotriazoles, alloxanes And maleimides. The amount of these sensitizers is usually 100 parts by weight or less based on 100 parts by weight of the 1,2-quinonediazide compound.

Surfactants are compounded to improve the coating properties and developability of the radiation-sensitive resin composition. Examples of such surfactants include polyoxyethylene lauryl ether and polyoxyethylene stearyl ether. ,
Nonionic surfactants such as polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate; F-Top EF301, EF303, EF352
(Manufactured by Shin-Akita Kaseisha), Megafax F171, F172, F173
(Manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-
382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-10
Fluorosurfactants such as 6 (manufactured by Asahi Glass Co.); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); acrylic acid or methacrylic acid (co) weight polyflow N
o.75 and No.95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK).

The content of these surfactants is 100% of the solid content of the composition.
It is usually 2 parts by weight or less per part by weight.

Further, in the present invention, a dye or a pigment can be blended in order to visualize the latent image of the radiation-irradiated portion or to reduce the influence of halation at the time of radiation-irradiation. Auxiliaries can also be included.

Examples of the dye for reducing the influence of halation include compounds having an azo bond, such as CISolvent Yellow 16, CISolvent Yellow 21, C.I.
I.Solvent Red 8, CISolvent Red 100, Yellow HM-1
123, Yellow HM-1124 (trade name, manufactured by Mitsui Toatsu Chemicals),
5-methyl-1-phenyl-4-phenylazopyrazole, 5-ethyl-3-methyl-1-phenyl-4-phenylazopyrazole, 3,5-dimethyl-1-phenyl-
4- (2,5-dichlorophenylazo) pyrazole, 1-
Phenyl-4-phenylazo-5-oxypyrazole,
3-methyl-1-phenyl-4-phenylazo-5-oxypyrazole, 1-phenyl-4- (2,5-dichlorophenylazo) -5-oxypyrazole, 1-ethyl-
3-methyl-4- (4-chloro-2-methylphenylazo) -5-oxypyrazole, 3-methyl-1-p-tolyl-4- (2-methoxy-4-nitrophenylazo)
-5-oxypyrazole, 3-ethyl-1-phenyl-
4- (4-methoxy-2-nitrophenylazo) -5
Oxypyrazole, 3-methyl-1-phenyl-4-
(2,4,5-trichlorophenylazo) -5-oxypyrazole, 3-methyl-1-phenyl-4- (4-chloro-2-nitrophenylazo) -5-oxypyrazole,
1-p-dimethylaminophenyl-3-methyl-4-phenylazo-5-oxypyrazole, 1-p-dimethylaminophenyl-3-methyl-4- (4-methyl-2-
Chlorophenylazo) -5-oxypyrazole, 1-p
-Dimethylaminophenyl-3-methyl-4- (4-methyl-2-nitrophenylazo) -5-oxypyrazole, 1-phenyl-4- (4-methoxyphenylazo)
-5-oxypyrazole, 1-phenyl-4-phenylazo-5-methylimidazole, 1-phenyl-2-methyl-4-phenylazo-5-ethylimidazole, 1
-Phenyl-2-methyl-4- (2,5-dichlorophenylazo) -5-methylimidazole, 1-phenyl-4
-Phenylazo-5-oxyimidazole, 1-phenyl-2-methyl-4-phenylazo-5-oxyimidazole, 1-phenyl-4- (2,5-dichlorophenylazo) -5-oxyimidazole, 1-ethyl-2 -Methyl-4- (5-chloro-2-methylphenylazo)-
5-oximidazole, 1-p-tolyl-2-methyl-4- (4-methoxy-2-nitrilephenylazo)-
5-oxyimidazole, 1-phenyl-2-ethyl-
4- (4-methoxy-2-nitrophenylazo) -5
Oxiimidazole, 1-phenyl-2-methyl-4-
(3,4,5-trichlorophenylazo) -5-oxyimidazole, 1-phenyl-2-methyl-4- (4-chloro-2-nitrophenylazo) -5-oxyimidazole, 1-p-dimethylamino Phenyl-2-methyl-4
-Phenylazo-5-oxyimidazole, 1-p-dimethylaminophenyl-2-methyl-4- (2-chloro-4-methylphenylazo) -5-oxyimidazole, 1-p-dimethylaminophenyl-2-methyl -4
-(4-methyl-2-nitrophenylazo) -5-oxyimidazole, 1-phenyl-4-methyl-5-phenylazoimidazole, 1-phenyl-2-methyl-4
-Ethyl-5-phenylazoimidazole, 1-phenyl-2,4-dimethyl-5- (2,5-dichlorophenylazo) imidazole, 1-phenyl-4-oxy-5-phenylazoimidazole, 1-phenyl-2 -Methyl-
4-oxy-5-phenylazoimidazole, 1-phenyl-4-oxy-5- (2,5-dichlorophenylazo) imidazole, 1-ethyl-2-methyl-4-oxy-5- (4-chloro-2 -Methylphenylazo) imidazole, 1-p-tolyl-2-methyl-4-oxy-
5- (4-methoxy-2-nitrophenylazo) imidazole, 1-phenyl-2-ethyl-4-oxy-5
(4-methoxy-2-nitrophenylazo) imidazole, 1-phenyl-2-methyl-4-oxy-5- (3,
4,5-trichlorophenylazo) imidazole, 1-phenyl-2-methyl-4-oxy-5- (4-chloro-
2-nitrophenylazo) imidazole, 1-p-dimethylaminophenyl-2-methyl-4-oxy-5-phenylazoimidazole, 1-p-dimethylaminophenyl-2-methyl-4-oxy-5- (2 -Chloro-4
-Methylphenylazo) imidazole, 1-p-dimethylaminophenyl-2-methyl-4-oxy-5- (4
-Methyl-2-nitrophenylazo) imidazole and the like. In addition to the compound having an azo bond, β-
Diketone derivatives can also be used, and such β-
As the diketone derivative, for example, 1,7-bis (4-hydroxyphenyl) -1,6-heptadiene-3,5-dione,
-(4-hydroxyphenyl) -7- (3-methoxy-
4-hydroxyphenyl) -1,6-heptadiene-3,5-
Dione, 1,7-bis- (3-methoxy-4-hydroxyphenyl) -1,6-heptadiene-3,5-dione, 1,7-
Bis- (2,4-dihydroxyphenyl) -1,6-heptadiene-3,5-dione, 1,7-bis- (2,3,4-trihydroxyphenyl) -1,6-heptadiene-3,5 -Zeon, 1
-(4-hydroxyphenyl) -7- (2,3,4-trihydroxyphenyl) -1,6-heptadiene-3,5-dione, 1,7-bis- (3-methoxy-4-hydroxyphenyl) -4,4-dimethyl-1,6-heptadiene-3,5-dione, 1,7-bis- (3-methoxy-4-hydroxyphenyl) -4,4-diethyl-1,6-heptadiene-3, 5−
Dione, 1,7-bis- (3-methoxy-4-hydroxyphenyl) -1,2,6,7-tetramethyl-1,6-heptadiene-3,5-dione, 1,7-bis- (3 -Methoxy-4-hydroxyphenyl) -1,2,4,4 ', 6,7-hexamethyl-
1,6-heptadiene-3,5-dione, 1,7-bis- (3-
Ethoxy-4-hydroxyphenyl) -1,6-heptadiene-3,5-dione, 1,7-bis- (3-butoxy-4-
(Hydroxyphenyl) -1,6-heptadiene-3,5-dione, 1- (3-methyl-4-hydroxyphenyl) -7
-(3-methoxy-4-hydroxyphenyl) -1,6-
Heptadiene-3,5-dione, 1- (3,5-dimethyl-4
-Hydroxyphenyl) -7- (3-methoxy-4-hydroxyphenyl) -1,6-heptadiene-3,5-dione, 1,7-bis- (3-methyl-4-hydroxyphenyl) -1,6 -Heptadiene-3,5-dione and the like.

These dyes and pigments are usually
It is blended at 0.5 to 10 parts by weight per 0 parts by weight.

Preparation of the composition of the present invention The composition of the present invention is prepared by dissolving a predetermined amount of an alkali-soluble resin, a 1,2-quinonediazide compound, various compounding agents and the like in the above-mentioned solvent, and filtering through a filter having a pore size of about 0.2 μm. Prepared.

What is important in the present invention is that the concentration of the acid component in the composition is 1.0 × 10 ⁻³ meq / g or less, preferably 0.8 × 10
^-3 meq / g or less. In general, if the concentration of the acid component is reduced to about 0.1 × 10 ⁻³ meq / g, the effect of the present invention is sufficiently exhibited.

That is, in a radiation-sensitive resin composition containing a general alkali-soluble resin, an acid component is contained at a relatively high concentration. This is because an acidic compound is used as a catalyst in the production of an alkali-soluble resin. This is because the decomposition or removal is not performed sufficiently.

However, according to the study of the present inventors, when the concentration of such an acid component is high, a large amount of peeling of the pattern occurs at the time of forming the pattern, and the peeling of the pattern is controlled by controlling the concentration to the above-mentioned low range. Has been found to be able to be effectively avoided.

In the present invention, the reduction of the concentration of the acid component in the composition is performed so that an acid compound is not generated or the acid compound is sufficiently removed when synthesizing the alkali-soluble resin as a main component of the composition. You can do this by doing For example, in the case of novolak resin, when synthesizing and recovering novolak resin, the internal temperature is 150 to 2 under reduced pressure.
00 ° C., preferably 160 to 190 ° C., for 1 to 7 hours,
Preferably, a method of heating for 1.5 to 5 hours to remove the acid catalyst, unreacted raw materials and reaction medium can be mentioned. If the internal temperature is less than 150 ° C. or the heating time is less than 1.5 hours, the removal of the acid catalyst becomes insufficient, and the internal temperature becomes 200 ° C.
If the temperature exceeds 0 ° C. or the heating time exceeds 7 hours, the novolak resin will deteriorate.

Further, in the present invention, in order to further reduce the acid component concentration of the composition, a neutralization treatment can be performed using an appropriate basic compound. Examples of the basic compound used in the neutralization treatment include primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-propylamine; and triamines such as triethylamine and methyldiethylamine. Tertiary amines; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide and choline; cyclic amines such as pyrrole and piperidine; Usually, up to 1 part by weight, preferably up to 0.1 part by weight, is added per 100 parts by weight of the composition to be treated.

Pattern formation The composition of the present invention forms a radiation-sensitive layer by applying the composition to a substrate such as a silicon wafer, a silicon wafer coated with aluminum or an aluminum alloy by spin coating, flow coating, roll coating, etc. The radiation-sensitive layer is irradiated with radiation through a predetermined mask pattern and developed with a developer to form a pattern.

Developer As the developer of the composition of the present invention, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine,
n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine,
Dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8-diazabicyclo- (5,4,0) -7-undecene, 1,5-diazabicyclo- ( An aqueous alkali solution obtained by dissolving (4,3,0) -5-nonane or the like is used. Further, a suitable amount of a water-soluble organic solvent, for example, an alcohol such as methanol or ethanol or a surfactant may be added to the developer.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

In the examples, evaluation was made using a silicon wafer on which aluminum was deposited.

The quantitative determination of the acid contained in the composition and the evaluation of the peeling of the resist were performed by the following methods.

Determination of acid; 50 g of the composition was put into a separating funnel, 30 ml each of ethyl acetate, diethyl ether and ultrapure water were added, and the mixture was shaken and allowed to stand. The aqueous layer was placed in an Erlenmeyer flask. Further, ethyl acetate and ultrapure water were added to the remaining composition layer in a volume of 20 ml each, and the mixture was shaken and allowed to stand.The aqueous layer was taken as an extract in an Erlenmeyer flask. Titration is carried out with an aqueous sodium hydroxide solution using phenolphthalein as an indicator to determine the acid content.

Evaluation of peeling: The composition applied on the wafer is exposed by a GCA 4800DSW reduction projector. Next, using a 2.4% by weight aqueous solution of tetraammonium hydroxide, development was performed at 25 ° C. for 60 seconds, rinsed with water, dried, and then observed with an optical microscope to see how a linear pattern having a width of 1 μm was peeled off. . Observation was performed at 50 places, and the degree of peeling was represented by the number of places where peeling occurred.

Synthesis Example 1 In a flask equipped with a stirrer, a cooling tube and a thermometer,
182 g (1.69 mol) of m-cresol, 594 g of p-cresol
(5.5 mol), 770 g (9.488 mol) of a 37% by weight aqueous solution of formaldehyde (formalin) and oxalic acid dihydrate 0.4
Charge 5 g (0.00357 mol), immerse the flask in an oil bath,
The mixture was stirred for 1 hour while maintaining the internal temperature at 100 ° C.
Thereafter, 304 g (2.81 mol) of m-cresol was further added, and the mixture was further reacted for 2 hours.

Then, the temperature of the oil bath was raised to 180 ° C. and maintained for 1 hour to remove unreacted formaldehyde and water. Further, while maintaining the oil bath temperature at 180 ° C., the pressure in the flask was reduced to 2 hours. M-cresol, p-cresol, formaldehyde and oxalic acid in the reaction were removed, and the novolak resin was recovered. The obtained resin is referred to as "novolak resin A".

Synthesis Example 2 In a flask similar to that used in Synthesis Example 1, 17.8 g (0.165 mol) of m-cresol and 53.4 g of 3,5-xylenol (0.
438 mol), p-cresol 44.4 g (0.411 mol), formalin 137.3 g (1.692 mol) and oxalic acid dihydrate 0.1
46 g (0.00116 mol) was charged, and the flask was immersed in an oil bath.
After stirring and reacting for 30 minutes while maintaining the internal temperature at 100 ° C, 71.0 g (0.657 mol) of m-cresol, 3,5-
13.4 g (0.110 mol) of xylenol was added and allowed to react for another 45 minutes.

Then, the temperature of the oil bath was raised to 180 ° C. and maintained for 1 hour to remove unreacted formaldehyde and water. Further, while maintaining the oil bath temperature at 180 ° C., the pressure in the flask was reduced to 2 hours. Removing the reaction m-cresol, p-cresol, 3,5-xylenol and oxalic acid,
The novolak resin was recovered. The obtained resin is referred to as "novolak resin B".

Synthesis Example 3 In a flask similar to that used in Synthesis Example 1, m-cresol 20.0 g (0.1854 mol), 3,5-xylenol 83.7 g
(0.6847 mol), 130.3 g (1.605 mol) of formalin and 0.731 g (0.0058 mol) of oxalic acid dihydrate, and the flask was immersed in an oil bath and stirred for 35 minutes while maintaining the internal temperature at 100 ° C. After letting it further, 80.1 g of m-cresol
(0.7417 mol) and 20.9 g of 3,5-xylenol (0.1712
Mol) was added and reacted for an additional 90 minutes.

Then, the temperature of the oil bath was raised to 180 ° C. and maintained for 1 hour to remove unreacted formaldehyde and water. Further, while maintaining the oil bath temperature at 180 ° C., the pressure in the flask was reduced to 2 hours. M-cresol, 3,5-xylenol and oxalic acid in the reaction were removed, and the novolak resin was recovered. The obtained resin is referred to as "novolak resin C".

Synthesis Example 4 In a flask similar to that used in Synthesis Example 1, 81.5 g (0.755 mol) of m-cresol, 21.0 g (0.1545 mol) of 2,3,5-trimethylphenol, 125.3 g (1.544 mol) of formalin and 1.558 g (0.012 mol) of acid dihydrate was charged, the flask was immersed in an oil bath, and the mixture was stirred and reacted for 1 hour while maintaining the internal temperature at 100 ° C., and then 20.4 g (0.189 mol) of m-cresol and 84.2 g (0.6181 mol) of 2,3,5-trimethylphenol was added, and the mixture was further reacted for 2 hours.

Next, the temperature of the oil bath was raised to 180 ° C. and maintained for 2 hours to remove unreacted formaldehyde and water. Further, while maintaining the oil bath temperature at 180 ° C., the pressure in the flask was reduced to 3 hours. M-cresol of the reaction, 2,3,5-
Trimethylphenol and oxalic acid were removed, and the novolak resin was recovered. The obtained resin is referred to as "novolak resin D".

Synthesis Example 5 In a flask similar to that used in Synthesis Example 1, 82.4 g (0.763 mol) of m-cresol, 11.8 g (0.087 mol) of 2,3,5-trimethylphenol, 37.6 g (0.348 mol) of p-cresol , 127.0 g (1.565 mol) of formalin and 1.578 g (0.0125 mol) of oxalic acid dihydrate were placed, the flask was immersed in an oil bath, and the mixture was stirred for 1 hour while maintaining the internal temperature at 100 ° C., and then further reacted. 20.6 g (0.191 mol) of m-cresol and 47.3 g (0.348 g) of 2,3,5-trimethylphenol
Mol) was added, and the mixture was further reacted for 100 minutes.

Then, the temperature of the oil bath was raised to 180 ° C. and maintained for 2 hours. Unreacted formaldehyde and water were distilled off. Further, while maintaining the oil bath temperature at 180 ° C., the pressure in the flask was reduced to 2 hours. M-cresol of the reaction, 2,3,5-
Trimethylphenol, p-cresol and oxalic acid were removed, and the novolak resin was recovered. The obtained resin is referred to as "novolak resin E".

Synthesis Example 6 In a flask similar to that used in Synthesis Example 1, m-cresol 86.4 g (0.80 mol) and 2,5-xylenol 12.2 g (0.1
0 mol), 27.2 g (0.20 mol) of 2,3,5-trimethylphenol, 146.1 g (1.8 mol) of formalin and oxalic acid 2
The hydrate was charged with 1.814 g (0.0144 mol), the flask was immersed in an oil bath, and reacted while stirring at an internal temperature of 100 ° C. for 2 hours. Thereafter, m-cresol 21.6 g (0.20 mol), 2, 12.2-g (0.10 mol) of 5-xylenol and 2,3,
109.0 g (0.80 mol) of 5-trimethylphenol was added, and the mixture was further reacted for 4 hours.

Next, the temperature of the oil bath was raised to 180 ° C. and maintained for 2 hours to remove unreacted formaldehyde and water. Further, while maintaining the oil bath temperature at 180 ° C., the pressure in the flask was reduced to 3 hours. M-cresol of the reaction, 2,3,5-
Trimethylphenol, 2,5-xylenol, p-cresol and oxalic acid were removed, and the novolak resin was recovered. The obtained resin is referred to as "novolak resin F".

Synthesis Example 7 In a flask similar to that used in Synthesis Example 1, 182 g (1.69 mol) of m-cresol, 594 g (5.5 mol) of p-cresol, 770 g (9.488 mol) of formalin and oxalic acid 2
The hydrate was charged with 0.45 g (0.00357 mol), the flask was immersed in an oil bath, and the reaction was carried out for 1 hour with stirring while maintaining the internal temperature at 100 ° C., and then 304 g (2.81 mol) of m-cresol was further added.
Was added, and the mixture was further reacted for 2 hours.

Then, the oil bath temperature was raised to 180 ° C. and maintained for 30 minutes to remove unreacted formaldehyde and water. Further, while maintaining the oil bath temperature at 180 ° C., the pressure in the flask was reduced to 2 hours. M-cresol, p-cresol and oxalic acid in the reaction were removed, and the novolak resin was recovered. The obtained resin is referred to as "novolak resin A '".

Synthesis Example 8 In a flask similar to that used in Synthesis Example 1, 17.8 g (0.165 mol) of m-cresol and 53.4 g of 3,5-xylenol (0.
438 mol), p-cresol 44.4 g (0.411 mol), formalin 137.3 g (1.692 mol) and oxalic acid dihydrate 0.1
46 g (0.00116 mol) was charged, and the flask was immersed in an oil bath.
After stirring and reacting for 30 minutes while maintaining the internal temperature at 100 ° C, 71.0 g (0.657 mol) of m-cresol and 3,3
13.4 g (0.110 mol) of 5-xylenol was added and another 45
Allowed to react for minutes.

Then, the oil bath temperature was raised to 170 ° C. and maintained for 30 minutes to remove unreacted formaldehyde and water.Furthermore, while maintaining the oil bath temperature at 170 ° C., the inside of the flask was depressurized, and over 30 minutes, Removing the reaction m-cresol, p-cresol, 3,5-xylenol and oxalic acid,
The novolak resin was recovered. The obtained resin is referred to as "novolak resin B '".

Example 1 100 g of the novolak resin A obtained in Synthesis Example 1 and 2,2
1 mol of 3,4,4'-tetrahydroxybenzophenone and 1,2
-Naphthoquinonediazide-5-sulfonic acid chloride 2.5
Ethyl cellosolve acetate 301 g with mole condensate 29 g
And filtered with a membrane filter having a pore size of 0.2 μm to prepare the composition of the present invention.

The acid concentration of this composition was 6.20 × 10 ⁻⁴ meq / g of composition.

Further, the obtained composition was applied on a wafer using a spinner, and then prebaked on a hot plate kept at 90 ° C. for 1 minute to form a resist film having a dry film thickness of about 1.8 μm.

The resist film was exposed and developed, and the presence or absence of peeling was observed. As a result, no peeling occurred.

Examples 2 to 8, Comparative Examples 1 to 3 A composition was prepared in the same manner as in Example 1 except that the content of the composition was changed as shown in Table 1, and the acid concentration was measured. It was measured and peeling was evaluated. The results are shown in Table 1 together with Example 1.

(Effect of the Invention) According to the present invention, in forming a resist pattern, peeling of the pattern is effectively prevented, and an extremely fine resist pattern can be formed.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takao Miura 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-60-125841 (JP, A) JP-A Sho 62-270951 (JP, A) JP-A-63-237053 (JP, A) JP-A-1-154145 (JP, A) JP-A-2-47656 (JP, A) JP-A-2-132442 (JP, A A) (58) Field surveyed (Int. Cl. ⁶ , DB name) G03F ^7/ 00-7/18

Claims (1)

(57) [Claims] 1. A radiation-sensitive resin composition containing an alkali-soluble resin, a 1,2-quinonediazide compound and a solvent, wherein the content of an acid component is adjusted to a range of 1.0 × 10 ⁻³ meq / g or less. A radiation-sensitive resin composition.