JP2000338660A - Positive type electron beam resist composition and production of resist pattern using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a positive type electron beam resist composition having high sensitivity and capable of forming a high definition pattern in a positive type electron beam resist composition containing a novolak resin and a quinonediazide sensitizer as principal components. SOLUTION: The electron beam resist composition contains (1) an alkali- soluble resin, (2) a quinonediazide compound obtained by allowing a polyphenol compound to react with 1,2-naphthoquinonediazide-4-sulfonyl chloride and/or 1,2-naphthoquinonediazide-5-sulfonyl chloride and (3) one or more compounds of the formula as principal components. In the formula, R1 is a 6-15C aryl or aralkyl, R2 and R3 are each H, a 1-15C linear or branched alkyl, an aryl or an aralkyl and R2 and R3 may be the same or different.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive electron beam resist composition used for producing a photolithography mask, a semiconductor integrated circuit, and the like, and a method for producing a resist pattern using the same.

[0002]

2. Description of the Related Art In recent years, as the degree of integration of semiconductor integrated circuits has increased, the sensitivity, resolution, contrast, residual film ratio after development, and dry etching resistance have been increased for positive resists and negative resists used in their manufacture. And the like, and conventional resists are becoming unable to cope.
The same can be said for the production of a photomask used for manufacturing a semiconductor integrated circuit, and a higher-performance radiation-sensitive positive or negative resist is required.

At present, lithography using an electron beam is frequently used for producing a photomask. As for a resist for producing a photomask, an attempt has been made to apply a resist mainly composed of novolak resin / naphthoquinonediazide, which has been conventionally used for lithography of a wafer, as an electron beam resist (Japanese Patent Laid-Open No. 63-1).
15162, JP-A-3-25184, JP-A-4-12357 and the like. This type of resist has high dry etching resistance and is suitable for producing a high-definition pattern.

In a resist containing novolak resin / naphthoquinonediazide as a main component, the structure and molecular weight of the novolak resin used as a binder greatly affect the properties. For example, it is known that in a novolak resin obtained by condensing m- and p-cresol with formaldehyde, increasing the content of p-cresol improves the contrast of the resist. (M. Hanabat
a, Journal of Photopolymer Science and Technology
1989, 2, 383). In addition, the molecular weight of the binder affects the heat resistance of the resist pattern, and when a novolak resin having a low molecular weight is used, sagging of the pattern occurs in a post-baking or dry etching step. However, when a novolak resin having a high p-cresol content or a high molecular weight resin is used, the dissolution rate of the resist film is reduced, the time required for development is increased, and the sensitivity is reduced.

[0005] Similar advantages and disadvantages also occur when the amount of naphthoquinonediazide as a dissolution inhibitor in the above resist is increased. That is, although the contrast of the resist is improved, the development time is increased and the sensitivity is reduced.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a high-sensitivity positive-type electron beam resist composition capable of forming a high-definition pattern for producing a photomask or a semiconductor integrated circuit by improving the above-mentioned disadvantages of the prior art. And a method of manufacturing a resist pattern using the same.

[0007]

Means for Solving the Problems In order to achieve the above object, a positive electron beam resist composition and a method for producing a resist pattern according to the present invention have the following constitutions. That is,
The main components are (1) an alkali-soluble resin, (2) a polyphenol compound and 1,2-naphthoquinonediazide-4.
A quinonediazide compound obtained by reacting -sulfonyl chloride and / or 1,2-naphthoquinonediazide-5-sulfonylchloride; and a positive-type compound comprising at least one compound represented by the general formula (1). An electron beam resist composition and a method for producing a resist pattern using the same.

[0008]

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(R ¹ represents an aryl group or aralkyl group having 6 to 15 carbon atoms, R ² and R ³ represent a hydrogen atom, a linear or branched alkyl group having 1 to 15 carbon atoms, an aryl group, Represents an aralkyl group; R ² and R ³ may be the same or different;

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The electron beam resist composition of the present invention
It contains one or more compounds represented by the general formula (1). General formula
By adding the compound represented by (1), the resist
Resist dissolution rate at the same development time
Is improved. R of the general formula (1)¹Has from 6 to 15 carbon atoms
Represents an aryl group or an aralkyl group;^Two, R^ThreeIs hydrogen
Atom, linear or branched alkyl having 1 to 15 carbon atoms
, An aryl group and an aralkyl group. At this time
R^Two, R^ThreeMay be the same or different. General formula
As an example of the compound represented by (1), benzene sulfone
Amide, N-methylbenzenesulfonamide, N-ethyl
Rubenzenesulfonamide, N, N-dimethylbenzene
Sulfonamide, Nn-butylbenzenesulfonamido
, Nt-butylbenzenesulfonamide, N, N-
Di-n-butylbenzenesulfonamide, benzenesulfur
Honanilide, N, N-diphenylbenzenesulfone
Mid, Np-tolylbenzenesulfonamide, No
-Tolylbenzenesulfonamide, Nm-tolylben
Zensulfonamide, N, N-di-p-tolylbenzene
Sulfonamide, p-toluenesulfonamide, N-meth
Tyl-p-toluenesulfonamide, N-ethyl-p-
Toluenesulfonamide, N, N-dimethyl-p-tolu
Ensulfonamide, Nn-butyl-p-toluene
Rufonamide, Nt-butyl-p-toluenesulfone
Amide, N, N-di-n-butyl-p-toluenesulfo
Amide, N-phenyl-p-toluenesulfonamido
, N, N-diphenyl-p-toluenesulfonamido
N, Np-tolyl-p-toluenesulfonamide, N
-M-tolyl-p-toluenesulfonamide, N, N-
Di-p-tolyl-p-toluenesulfonamide, N, N
-Di-m-tolyl-p-toluenesulfonamide, o-
Toluenesulfonamide, N-methyl-o-toluenes
Rufonamide, N-ethyl-o-toluenesulfonami
, N, N-dimethyl-o-toluenesulfonamide,
Nn-butyl-o-toluenesulfonamide, Nt
-Butyl-o-toluenesulfonamide, N, N-di-
n-butyl-o-toluenesulfonamide, N-phenyl
Ru-o-toluenesulfonamide, N, N-diphenyl
-O-toluenesulfonamide, Np-tolyl-o-
Toluenesulfonamide, Nm-tolyl-o-tolue
N, N-di-p-tolyl-o-toluene
Ensulfonamide, N, N-di-m-tolyl-oot
Ruene sulfonamide, naphthalene sulfonamide, N
-Methylnaphthalenesulfonamide, N-ethylnaphtha
Lensulfonamide, N, N-dimethylnaphthalenesul
Honamide, Nn-butylnaphthalenesulfonami
, Nt-butylnaphthalenesulfonamide, N, N
-Di-n-butylnaphthalenesulfonamide, N-fe
Nilnaphthalenesulfonamide, N, N-diphenylna
Phthalenesulfonamide, Np-tolylnaphthalene
Rufonamide, No-tolylnaphthalenesulfonami
, Nm-tolylnaphthalenesulfonamide, N, N
-Di-p-tolylnaphthalenesulfonamide, N, N-
Di-m-tolylnaphthalenesulfonamide, 2,3-di
Methylbenzenesulfonamide, N-methyl-2,3-
Dimethylbenzenesulfonamide, Nn-butyl-
2,3-dimethylbenzenesulfonamide, p-ethyl
Benzenesulfonamide, N-methyl-p-ethylben
Zensulfonamide, N-ethylbenzenesulfonamido
, N, N-dimethylbenzenesulfonamide, Nn
-Butyl-p-ethylbenzenesulfonamide and the like.
I can do it. These compounds may be added alone or in combination.
Numbers may be mixed. Compound represented by the general formula (1)
Chi, R¹Is an aryl group having 6 to 10 carbon atoms, an aralkyl group
Or R^Two, R^ThreeIs hydrogen atom, carbon number 1 to 10
Compounds that are linear or branched alkyl groups up to
It is preferably used. Again, R^Two, R^ThreeAre the same
May also be different. Examples of such compounds include:
Benzenesulfonamide, N-methylbenzenesulfone
Amide, N-ethylbenzenesulfonamide, N, N-
Dimethylbenzenesulfonamide, Nn-butylben
Zensulfonamide, Nt-butylbenzenesulfone
Amide, N, N-di-n-butylbenzenesulfonamido
, P-toluenesulfonamide, N-methyl-p-to
Ruene sulfonamide, N-ethyl-p-toluene sulf
Honamide, N, N-dimethyl-p-toluenesulfone
Amide, Nn-butyl-p-toluenesulfonamido
, Nt-butyl-p-toluenesulfonamide,
N, N-di-n-butyl-p-toluenesulfonami
And o-toluenesulfonamide. Sa
Furthermore, N-methylbenzenesulfonamide, N-ethyl
Benzenesulfonamide, Nn-butylbenzenesulfur
Honamide, N-methyl-p-toluenesulfonamido
, N-ethyl-p-toluenesulfonamide, Nn
-Butyl-p-toluenesulfonamide, Nt-butyl
R such as ru-p-toluenesulfonamide ^Two, R^ThreeNozomi
It is particularly preferable to use a compound in which this is a hydrogen atom.
No.

As a resist using such sulfonamides, a positive photoresist composition disclosed in JP-A-3-28849 is known. However, the substituent (R ² , R ³
Is an aryl group, but in the present invention, it has been found that not only an aryl group but also an alkyl group works well as a composition.

The content of the compound represented by the general formula (1) is from 0.05 to 10 based on the total weight of the resist composition.
%, Preferably 0.1 to 5% by weight. If the content is small, the effect of improving sensitivity and development speed is not exhibited, and if the content is large, uniformity of development may be impaired or the residual film ratio may be extremely reduced.

As the alkali-soluble resin used in the electron beam resist composition of the present invention, polyvinyl phenol and novolak resin are preferable, and novolak resin is particularly preferable.

The novolak resin is obtained by condensing a phenol compound and an aldehyde compound in the presence of an acid catalyst. Examples of phenol compounds include phenol, m-cresol, p-cresol, o-cresol, xylenol, m-ethylphenol, p-ethylphenol, m-methoxyphenol, p-methoxyphenol, o-methoxyphenol, 3, 5-dimethoxyphenol, 2-methoxy-4-methylphenol,
m-ethoxyphenol, p-ethoxyphenol, p
-Chlorophenol, o-chlorophenol, catechol and the like. These phenol compounds may be used alone or as a mixture of two or more. Of these, cresol is preferably used, and a mixture of m-cresol and p-cresol is more preferably used. A preferred mixing ratio of m-cresol / p-cresol is 20/80 to 70/30, more preferably 25/80.
/ 75 to 60/40.

Examples of aldehyde compounds include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-
Chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-
Examples thereof include hydroxybenzaldehyde, p-ethylbenzaldehyde, pn-propylbenzaldehyde, pn-butylbenzaldehyde, furfural, and chloroacetaldehyde. These aldehyde compounds may be used alone or as a mixture of two or more. Among these aldehydes, formaldehyde,
Preferably, paraformaldehyde is used.

The condensation reaction between the phenol compound and the aldehyde compound is generally carried out using an acid catalyst. Examples of the acid catalyst include inorganic or organic acids such as oxalic acid, formic acid, acetic acid, p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, and phosphoric acid.

The condensation reaction is carried out without a solvent or in an organic solvent. Examples of the organic solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol and 1-butanol; cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; cellosolve esters such as methyl cellosolve acetate and ethyl cellosolve acetate; Tetrahydrofuran,
Ethers such as 1,4-dioxane are preferably used.

The novolak resin thus obtained generally contains a low molecular weight component such as a binuclear product obtained by condensing two phenol units and a trinuclear product obtained by condensing three phenol units.
Among such low molecular weight components, there are components that cause scum and deteriorate the pattern shape. When the synthesized novolak contains a large amount of these low molecular weight components, it is preferable to remove them by an appropriate operation to reduce the total content of binuclear and trinuclear bodies to 10% or less.

The following method can be used to remove low molecular weight components from the novolak resin.

(1) Extraction method Novolak resin is pulverized finely, and benzene, toluene,
A low molecular weight component is extracted by stirring at a certain temperature with an organic solvent such as xylene, chlorobenzene and dichlorobenzene, or a mixture of water and an organic solvent such as methanol and ethanol. (2) Reprecipitation method Novolak resin was treated with methanol, ethanol, acetone,
Dissolve in organic solvents such as ethyl cellosolve. Then
A poor solvent such as water, petroleum ether, or hexane is dropped into the novolak solution, or a novolak solution is dropped into the poor solvent to precipitate and separate a novolak resin, followed by drying. (3) Separation method Novolak resin was treated with methanol, ethanol, acetone,
Dissolve in a mixed solvent of a water-miscible organic solvent such as ethyl cellosolve and a water-immiscible organic solvent such as ethyl cellosolve acetate and propylene glycol monomethyl ether acetate, add water dropwise to separate two layers, and separate the organic layer. And concentrate.

The novolak resin preferably used in the electron beam resist composition of the present invention has a weight average molecular weight of 1,000 to 150 by adjusting the degree of polymerization and removing low molecular weight components.
00 is preferable. More preferably 1500 to
10,000. By adjusting the molecular weight and molecular weight distribution of the resin, an electron beam resist composition having a rectangular pattern and high sensitivity can be obtained. The weight average molecular weight is measured by gel permeation chromatography in terms of polystyrene.

The electron beam resist composition of the present invention is obtained by reacting 1,2-naphthoquinonediazide-4-sulfonyl chloride and / or 1,2-naphthoquinonediazide-5-sulfonyl chloride as a photosensitizer with a polyphenol compound. Contains quinonediazide compounds.

The polyphenol compound used may be any aromatic compound having two or more phenolic hydroxyl groups. Examples include polyhydroxybenzenes such as hydroquinone, catechol, resorcinol, pyrogallol, 2,3,4-trihydroxybenzophenone, 2,4,4′-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, , 3,4-Trihydroxy-2'-methylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3,4,3'-tetrahydroxybenzophenone, 2,2 ', 4,4'- Tetrahydroxybenzophenone, 2,2'3,4-tetrahydroxy-
4'-methylbenzophenone, 2,3,4,4'-tetrahydroxy-3'-methoxybenzophenone, 2,
2 ', 3,4,6'-pentahydroxybenzophenone, 2,4,6,3', 4'-pentahydroxybenzophenone, 2,3,4,2 ', 4'-pentahydroxybenzophenone, 2,3 4,2 ′, 5′-pentahydroxybenzophenone, 2,4,6,3 ′, 4 ′, 5 ′
-Hexahydroxybenzophenone, 2,3 ', 4
4 ', 5'6-hexahydroxybenzophenone 2,
Polyhydroxybenzophenones such as 3,4,3 ′, 4 ′, 5′-hexahydroxybenzophenone;
3,4-trihydroxyphenylpentyl ketone, 2,
Polyhydroxyphenyl alkyl ketones such as 3,4-trihydroxyphenylhexyl ketone; bis (2,4
-Dihydroxyphenyl) methane, bis (2,3,4-
Bis (polyhydroxyphenyl) alkanes such as trihydroxyphenyl) methane and bis (2,4-dihydroxyphenyl) propane; gallic acid esters such as methyl gallate, ethyl gallate, propyl gallate and phenyl gallate, bis (2,3,4-trihydroxybenzoyl) methane, bis (3-acetyl-4,5,6-trihydroxyphenyl) methane, bis (2,3,4-trihydroxybenzoyl) benzene, bis (2,4 , 6-
Bis (polyhydroxybenzoyl) alkane or bis (polyhydroxybenzoyl) aryls such as trihydroxybenzoyl) benzene, 2,3,4-biphenyltriol, 3,4,5-biphenyltriol, 3,
5,3′5′-biphenyl terol, 2,2 ′, 4
Polyhydroxybiphenyls such as 4'-biphenylterol, 4,4 ', 3 ", 4" -tetrahydroxy-
3,3 ′, 5,5′-tetramethyltriphenylmethane, 4,4 ′, 2 ″, 3 ″, 4 ″ -pentahydroxy-3,3 ′, 5,5′-tetramethyltriphenyl Examples thereof include methane and polyhydroxytriphenylmethanes such as 2,2′3,3 ′, 4,4′-hexahydroxy-5,5′-diacetyltriphenylmethane. These polyphenol compounds may be used alone or in combination of two or more. Of these polyphenol compounds, gallic esters are preferably used, and alkyl gallate, particularly methyl gallate and ethyl gallate, are particularly preferably used.

The quinonediazide compound obtained from alkyl gallate and naphthoquinonediazidosulfonyl chloride is generally one of the hydrogens of the hydroxyl group of alkyl gallate.
Component (monoester) in which two of them are substituted with a naphthoquinonediazidosulfonyl group, component (diester) in which two of the hydrogens in the hydroxyl group are replaced with a naphthoquinonediazidosulfonyl group, and all three hydrogen atoms in the hydroxyl group are substituted with a naphthoquinonediazidosulfonyl group. It becomes a mixture of the components (triesters). The content of the triester in the quinonediazide compound is 30 to 65% by weight.
Is preferred. When the content of the triester increases beyond this range, the sensitivity decreases. In addition, when the size becomes smaller, the film loss of the unexposed portion becomes larger, and the pattern shape is deteriorated. The content of the entire quinonediazide compound in the resist solids is preferably 10 to 25% by weight.

The electron beam resist composition of the present invention preferably contains, as an additive, a compound having 2 to 20 phenol nuclei in the molecule and having a molecular weight of 200 to 2,000. Among these compounds, it is more preferable to use the compound represented by the general formula (2) and / or a phenol novolak resin. The compound represented by the general formula (2) and the phenol resin may be used alone or simultaneously, and the combination is not particularly limited. R ⁴ , R ⁵ and R ^{6 in the} general formula (2) represent one selected from the group consisting of a hydrogen atom, an alkyl group, an aralkyl group and an aryl group;
R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R
¹⁴ represents one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, and an alkyl group. R ^{7 to} R ¹⁴ may be the same or different. m represents 0 to 3 and n represents 0 to 1.

[0026]

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Examples of the compound represented by the general formula (2) are shown below, but the present invention is not limited thereto.

[0028]

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[0029]

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The phenol novolak resin preferably used as an additive in the electron beam resist composition of the present invention includes:
It is obtained by condensing an unsubstituted phenol and an aldehyde compound using an acid catalyst. The aldehyde compound used here may be any compound as long as it can condense with an unsubstituted phenol to form a resin. Examples include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m
-Chlorobenzaldehyde, p-chlorobenzaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde,
Examples thereof include p-ethylbenzaldehyde, pn-propylbenzaldehyde, pn-butylbenzaldehyde, furfural, and chloroacetaldehyde. These aldehyde compounds may be used alone or as a mixture of two or more. Among these aldehyde compounds, it is preferable to use formaldehyde and paraformaldehyde.

Examples of the acid catalyst used in the condensation reaction between the phenol and the aldehyde compound include oxalic acid, formic acid, acetic acid,
p-Toluenesulfonic acid, hydrochloric acid, sulfuric acid, phosphoric acid and the like.

The phenol novolak resin preferably used as an additive in the present invention has a binuclear content of 1 to 10% by weight and a trinuclear content of 20% by weight in the resin.
That is all. In order to obtain such a phenol novolak resin, first, a phenol is mixed at a ratio of about 4 to 30 mol times with respect to the aldehyde compound, an acid catalyst is added thereto, and the mixture is heated to carry out a condensation reaction. obtain. The condensate is subjected to distillation under reduced pressure to remove binuclear substances and to remove 2
The desired phenol novolak resin can be obtained by controlling the content of the core. Although the phenol novolak resin thus obtained can be used as it is, a phenol having an arbitrary molecular weight and satisfying the ratio of the polynuclear is obtained by further adding an aldehyde compound to the resin and performing a condensation reaction. Novolak resins can also be obtained.

The phenol novolak resin used as an additive in the present invention contains a tetranuclear or higher component.
It is preferable that the content of tetranuclear is 5 to 20% by weight, and that the content of trinuclear is 2 to 15 times the content of tetranuclear by weight ratio. Components with four or more nuclei are effective for improving the residual film ratio.

The content of the additive in the resist solids is 5
-25% by weight, more preferably 10-25% by weight. Further, it is preferable to use an addition amount smaller than the addition amount of the alkali-soluble resin used as the binder.

The electron beam resist composition of the present invention can be obtained by dissolving the above components in a solvent. The solvent is not particularly limited as long as it has good coatability on the substrate to be processed and high solubility of the resist solids. Examples of preferably used solvents include ethyl acetate, butyl acetate, amyl acetate, methyl propionate, ethyl propionate,
Esters such as methyl butyrate, ethyl butyrate, methyl benzoate, methyl lactate, ethyl lactate, γ-butyrolactone, cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve, cellosolve esters such as methyl cellosolve acetate, ethyl cellosolve acetate and butyl cellosolve acetate , Propylene glycol ether esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and ethers such as 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 1,4-dioxane, and anisole Ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone; Solvent selected from the emissions polar solvent or these solvents solvent plurality mixed, and the like. The amount of the solvent used is not particularly limited, but is generally 65 to 95% by weight based on the whole resist composition.

A surfactant, an adhesion improver and the like can be added to the electron beam resist composition of the present invention as needed.

A fine pattern is formed by applying the electron beam resist composition of the present invention on a substrate to be processed, exposing the pattern with an electron beam, and developing with an alkali developing solution.

The developer used for developing the electron beam resist composition of the present invention includes, for example, alkali metal hydroxides, carbonates, phosphates, silicates, metasilicates, borates and the like. Inorganic alkalis, propylamine, dipropylamine, dibutylamine, methyldiethylamine,
Pyrrole, 2,2-dimethylpyrrole, β-picoline,
Amines such as collidine, piperidine, piperazine, triethylenediamine, 2-diethylaminoethanol, 2-aminoethanol and diethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide and choline; and bases such as ammonia. An aqueous solution containing one or more kinds is exemplified. Among these, a developer containing an alkali metal ion, a weak acid ion and an amine is particularly preferably used. By using this developer for developing the electron beam resist composition of the present invention, a resist pattern free from uneven development and scum can be obtained.

A surfactant can be added to the developer used for developing the electron beam resist composition of the present invention, if necessary, for improving wettability and preventing uneven development.

As a developing method, a known method, for example, an immersion developing method, a spray developing method, a paddle developing method, or the like can be used. Further, the development temperature is not particularly limited.
The temperature is generally 30 ° C., and it is generally preferable to develop at a constant temperature of about 20 ° C.

[0041]

The present invention will be specifically described below with reference to examples.

Example 1 (1) Preparation of Novolak 40 parts of m-cresol, 60 parts of p-cresol and 0.5 part of oxalic acid were placed in a three-necked flask equipped with a reflux condenser, heated to 100 ° C., and stirred. While reacting, 46 parts of 37% formalin was added dropwise. After completion of dropping, 4 at 100 ° C
After stirring for an hour, a reaction mixture was obtained. The reaction mixture was heated to 160 ° C. under atmospheric pressure to distill off water and a small amount of raw materials, and then distilled to 10 mmHg and a final temperature of 220 ° C. to remove unreacted raw materials to obtain a novolak resin.

Gel permeation chromatography (column: Shodex KF-804 + KF-8
03 + KF-802, solvent: tetrahydrofuran, detector: photodiode array detector), the weight average molecular weight (in terms of polystyrene) of this novolak was 225.
9, the number average molecular weight was 1015, the molecular weight dispersion was 2.23, the binuclear content was 10.5% by weight, and the trinuclear content was 5.7% by weight. One part of this novolak was taken, dissolved in 4.5 parts of methanol, and 1.9 parts of water was added dropwise with stirring to precipitate the novolak. Remove the supernatant,
The precipitated novolak was taken out and vacuum dried at 50 ° C. for 24 hours. 0.51 part of novolak was obtained.

The weight-average molecular weight (in terms of polystyrene) of this novolak determined by gel permeation chromatography was 2,750, the number-average molecular weight was 14,10, the molecular weight dispersion was 1.95, and the binucleate content was 6.1. %, The trinuclear content was 3.0% by weight. It was confirmed that this novolak had a lower molecular weight content than the initial novolak. This is designated as novolak resin A.

(2) Preparation of quinonediazide compound 15.0 g (81 mmol) of methyl gallate and 1,2-
Naphthoquinonediazide-4-sulfonyl chloride 41.
0 g (153 mmol) was dissolved in 220 ml of dioxane and heated to 40 ° C. To this solution, a mixture of 15.4 g (153 mmol) of triethylamine and 65 ml of dioxane was added dropwise, and the mixture was stirred for 5.5 hours. The reaction mixture was poured into water, and the precipitate was collected by filtration, washed, and dried under vacuum to obtain 41.0 g of a yellow powder. The content of triester was determined by high performance liquid chromatography to be 48%. This is designated as quinonediazide compound a.

(3) Preparation of resist composition The following raw materials were mixed to prepare a resist solution. 9.9 parts of novolak resin A prepared in (1) 2.3 parts of quinonediazide compound a prepared in (2) 2.3 parts of propylene glycol monometer ether acetate
67.2 parts N, N, -dimethylformamide 20 parts Nn-butyl-p-toluenesulfonamide 0.6
Part of surfactant "Troysol" 366 (TOROY CH
EMICAL) 0.03 parts.

(4) Resist process and evaluation The resist composition prepared in (3) was applied to a chrome blank using a spinner, baked in an oven at 100 ° C. for 10 minutes, and a 0.5 μm-thick coated film sample was obtained. Produced. An acceleration voltage of 2 was applied to the coating film sample using an electron beam exposure apparatus.
0.5 mm x 0.5 mm at 0 kV and irradiation current of 0.1 nA
Were subjected to scanning exposure while sequentially changing the exposure time. Then, development was carried out with a developer DVL MA-50 (manufactured by Toray Industries, Inc.) for 1 minute, rinsed with pure water, and dried.

The resist film thickness of the unexposed portion and the exposed rectangular region of the sample was sequentially measured. For each exposed portion, calculate the amount of exposure (ie, the value obtained by dividing the product of the irradiation current and the exposure time by the area) and the remaining film ratio (the value obtained by dividing the exposed portion film thickness by the coating film thickness), and calculate the remaining film ratio. A sensitivity curve was plotted against the log of the exposure. From this sensitivity curve, the exposure amount at which the residual film ratio became 0 was determined as the sensitivity value. A smaller value indicates higher sensitivity. The unexposed portion residual film ratio was determined from the ratio between the coating film thickness and the unexposed portion film thickness after development. Furthermore, a tangent was drawn at the intersection of the sensitivity curve and the X axis, and the contrast γ was calculated from the slope.

The sensitivity was 4.7 μC / cm ² , the residual film ratio in the unexposed area was 90%, and γ was 3.1, indicating high sensitivity.
Further, a 0.5 μm line-and-space pattern was prepared, and the cross section thereof was observed using a scanning electron microscope. As a result, a good rectangular pattern (resist profile) having no footing or scum of the pattern was formed.

Example 2 (1) Preparation of phenol novolak resin 500 g of phenol and 43.2% aqueous 37% formalin solution
g of oxalic acid, and 1.4 g of oxalic acid dihydrate were added thereto.
The reaction was performed at 0 ° C. for 4 hours. The reaction product mixture is then heated to 160 ° C. under atmospheric pressure to remove water and a small amount of phenol, and to a final 20 mm Hg, 170
Heated to ° C. to separate unreacted phenol. Thereafter, the mixture was heated to 6 mmHg and 210 ° C. to remove phenol. Next, distillation was performed to 3 mmHg and a final temperature of 250 ° C. using a device equipped with a McMahon packing having a diameter of 15 mm and a height of 20 mm to obtain a bottom product. 40g of this canned product and 37
Oxalic acid by mixing with 2.4 g of a 0.2% aqueous solution of formalin.
11 g was added and reacted at 100 ° C. for 2 hours. Then, the obtained reaction product was heated to 100 to 150 ° C. under atmospheric pressure to dehydrate it, and further heated to 280 mmHg and 170 ° C. to remove water to obtain a desired phenol novolak resin. The binuclear body of this phenol novolak resin, 3
The contents of the nucleolus and the tetranuclear were 7.3% by weight and 37.
9% by weight and 9.5% by weight. The content of each polynuclear was determined by gel permeation chromatography (column: Tosoh G4000HXL + G2500HXL + G2
000HXL + G2000HXL, solvent: tetrahydrofuran, detector: differential refractometer).

(2) Preparation of resist A resist solution was prepared by mixing the following raw materials. 7.8 parts of novolak resin A prepared in Example 1 (1) Quinonediazide compound a prepared in Example 1 (2)
2.2 parts Phenol novolak resin synthesized in (1) 2.2 parts Propylene glycol monometer ether acetate
66.6 parts N, N dimethylformamide 20 parts N-ethyl-p-toluenesulfonamide 1.2 parts Surfactant "Troysol" 366 (TOROY CH)
EMICAL) 0.03 parts.

(3) Resist Process and Evaluation Evaluation was performed in the same process as in Example 1. The sensitivity is 3.
8 μC / cm ² , the remaining film ratio of the unexposed portion is 91%, and γ is 3.
0, indicating a very high sensitivity. 0.5 μm
A line and space pattern was prepared, and its cross section was observed using a scanning electron microscope. As a result, the resist profile was good.

Example 3 (1) Preparation of Novolak A novolak resin was obtained in the same manner as in Example 1 from 30 parts of m-cresol, 70 parts of p-cresol, 0.5 part of oxalic acid, and 49 parts of 37% formalin. . The weight average molecular weight (in terms of polystyrene) of this novolak determined by gel permeation chromatography was 2130, the number average molecular weight was 790, the molecular weight dispersion was 2.69, the binuclear substance content was 11.5% by weight, Trinuclear content: 5.9% by weight
Met. Take 1 part of this novolak and add methanol 4.
The mixture was dissolved in 7 parts, and 1.9 parts of water was added dropwise with stirring to precipitate novolak. The supernatant was removed, and the precipitated novolak was taken out and vacuum-dried at 50 ° C. for 24 hours.
0.51 part of novolak was obtained.

The weight average molecular weight (in terms of polystyrene) of this novolak determined by gel permeation chromatography was 2520, the number average molecular weight was 1240, the molecular weight dispersion was 2.03, and the binuclear content was 6.8. %, The trinuclear content was 3.2% by weight. It was confirmed that this novolak had a lower molecular weight content than the initial novolak. This is referred to as novolak resin B.

(2) Preparation of Resist A resist solution was prepared by mixing the following raw materials. 7.5 parts of novolak resin B prepared in (1) Quinonediazide compound a prepared in Example 1 (2)
2.0 parts Phenol novolak resin prepared in Example 2 (1)
2.2 parts propylene glycol monometer ether acetate
77.5 parts N, N-dimethylformamide 10.0 parts N, N-dimethylbenzenesulfonamide 0.3 parts Surfactant "Troysol" 366 (TOROY CH)
EMICAL) 0.03 parts.

(3) Resist Process and Evaluation Evaluation was performed by the same process as in Example 1. The sensitivity is 5.
3 μC / cm ² , the remaining film ratio of the unexposed portion is 93%, and γ is 2.
Nine. Further, a 0.5 μm line-and-space pattern was prepared, and its cross section was observed using a scanning electron microscope. As a result, the resist profile was good.

Example 4 (1) Preparation of novolak A novolak resin was obtained in the same manner as in Example 1 from 45 parts of m-cresol, 55 parts of p-cresol, 0.5 part of oxalic acid and 46 parts of 37% formalin. . The weight-average molecular weight (in terms of polystyrene) of this novolak determined by gel permeation chromatography was 2050, the number-average molecular weight was 900, the molecular weight dispersion was 2.27, the binucleate content was 9.5% by weight, The trinuclear content was 6.6% by weight.

One part of the novolak was taken, dissolved in 4.5 parts of methanol, and 1.9 part of water was added dropwise with stirring to precipitate the novolak. The supernatant was removed, and the precipitated novolak was taken out and vacuum-dried at 50 ° C. for 24 hours. 0.54 parts of novolak were obtained. The weight average molecular weight (in terms of polystyrene) of this novolak determined by gel permeation chromatography was 2890,
The number average molecular weight is 1460, the molecular weight dispersion is 1.98, the binuclear content is 6.1% by weight, and the trinuclear content is 3.
It was 0% by weight. It was confirmed that this novolak had a lower molecular weight content than the initial novolak. This is designated as novolak resin C.

(2) Preparation of resist composition The following raw materials were mixed to prepare a resist solution. 7.8 parts of novolak resin C prepared in (1) Quinonediazide compound a prepared in Example 1 (2)
2.2 parts Phenol novolak resin prepared in Example 2 (1)
2.2 parts propylene glycol monometer ether acetate
66.8 parts N, N-dimethylformamide 20 parts p-Toluenesulfonanilide 1.0 part Surfactant "Troysol" 366 (TOROY CH)
EMICAL) 0.03 parts.

(3) Resist Process and Evaluation A coating film sample was prepared in the same manner as in Example 1, and was exposed, developed, and evaluated. The sensitivity was 5.2 μC / cm ² , the residual film ratio in the unexposed area was 82%, and γ was 2.8.

Further, a 0.5 μm line-and-space pattern was prepared, and its cross section was observed using a scanning electron microscope. As a result, the resist profile was good.

Example 5 (1) Preparation of novolak A novolak resin was obtained in the same manner as in Example 1 from 40 parts of m-cresol, 60 parts of p-cresol, 0.5 part of oxalic acid and 46 parts of 37% formalin. . The weight average molecular weight (in terms of polystyrene) of this novolak determined by gel permeation chromatography was 6,780, the number average molecular weight was 1,260, the molecular weight dispersion was 5.38, the binucleate content was 10.1% by weight, The trinuclear content was 5.6% by weight.

One part of this novolak was taken, dissolved in 5.0 parts of methanol, and 2.2 parts of water was added dropwise with stirring to precipitate the novolak. The supernatant was removed, and the precipitated novolak was taken out and vacuum-dried at 50 ° C. for 24 hours. 0.49 parts of novolak were obtained. The weight-average molecular weight (in terms of polystyrene) of this novolak determined by gel permeation chromatography was 8250,
The number average molecular weight is 3,600, the molecular weight dispersion is 2.29, the binuclear content is 6.5% by weight, and the trinuclear content is 3.
It was 2% by weight. It was confirmed that this novolak had a lower molecular weight content than the initial novolak. This is referred to as novolak resin D.

(2) Preparation of quinonediazide compound The hydroxyl group of 2,3,4,4'-tetrahydroxybenzophenone was converted to naphthoquinone-1,2-diazide-4-sulfonic acid in the same manner as in (2) of Example 1. A 53% esterified quinonediazide compound b was prepared.

(3) Preparation of Resist A resist solution was prepared by mixing the following raw materials. 7.8 parts of novolak resin D prepared in (1) 2.2 parts of quinonediazide compound b prepared in (2) 2.2 parts of the following compound (3) 2.2 parts propylene glycol monomethyl ether acetate
66.3 parts N, N-dimethylformamide 20 parts Nn-butyl-p-toluenesulfonamide 1.5
Part of surfactant "Troysol" 366 (TOROY CH
EMICAL) 0.03 parts.

[0066]

Embedded image

(4) Resist Process and Evaluation A coating film sample was prepared in the same manner as in Example 1, and was exposed, developed, and evaluated. The sensitivity was 3.9 μC / cm ² , the residual film ratio in the unexposed area was 90%, and γ was 3.1. Further, a 0.5 μm line-and-space pattern was prepared, and its cross section was observed using a scanning electron microscope. As a result, the resist profile was good.

Example 6 (1) Preparation of novolak A novolak resin was obtained in the same manner as in Example 1 from 55 parts of m-cresol, 45 parts of p-cresol, 0.5 part of oxalic acid and 46 parts of 37% formalin. . The weight-average molecular weight (in terms of polystyrene) of this novolak determined by gel permeation chromatography was 2270, the number-average molecular weight was 900, the molecular weight dispersion was 2.58, the binucleate content was 9.8% by weight, The trinuclear content was 6.9% by weight.

One part of the novolak was taken, dissolved in 4.0 parts of methanol, and 2.4 parts of water was added dropwise with stirring to precipitate the novolak. The supernatant was removed, and the precipitated novolak was taken out and vacuum-dried at 50 ° C. for 24 hours. 0.56 parts of novolak were obtained. The weight average molecular weight (in terms of polystyrene) of this novolak determined by gel permeation chromatography was 2970,
The number average molecular weight is 1395, the molecular weight dispersion is 2.13, the binuclear content is 6.2% by weight, and the trinuclear content is 2.
It was 6% by weight. It was confirmed that this novolak had a lower molecular weight content than the initial novolak. This is called novolak resin E.

(2) Preparation of resist composition The following raw materials were mixed to prepare a resist solution. 7.6 parts of novolak resin E prepared in (1) Quinonediazide compound a prepared in Example 1 (2)
3.0 parts Phenol novolak resin prepared in Example 2 (1)
1.6 parts propylene glycol monometer ether acetate
65.8 parts N-methyl-p-toluenesulfonamide 2.0 parts N, N-dimethylformamide 20 parts Surfactant "Troysol" 366 (TOROY CH)
EMICAL) 0.03 parts.

(3) Resist Process and Evaluation A coating film sample was prepared in the same manner as in Example 1, and was exposed, developed, and evaluated. The sensitivity was 4.5 μC / cm ² , the residual film ratio in the unexposed area was 93%, and γ was 3.4. Further, a 0.5 μm line-and-space pattern was prepared, and its cross section was observed using a scanning electron microscope. As a result, the resist profile was good.

Example 7 (1) Preparation of Resist Composition A resist solution was prepared by mixing the following raw materials. 7.6 parts of novolak resin E prepared in Example 6 (1) Quinonediazide compound a prepared in Example 1 (2)
3.0 parts Phenol novolak resin prepared in Example 2 (1)
1.6 parts propylene glycol monometer ether acetate
59.8 parts N-methyl-p-toluenesulfonamide 8.0 parts N, N-dimethylformamide 20 parts Surfactant "Troysol" 366 (TOROY CH)
EMICAL) 0.03 parts.

(2) Resist Process and Evaluation Coating samples were prepared in the same manner as in Example 1, and were exposed, developed, and evaluated. The sensitivity was 4.5 μC / cm ² , the residual film ratio in the unexposed area was 89%, and γ was 2.8. Further, a line and space pattern of 0.5 μm was formed, and the cross section thereof was observed using a scanning electron microscope. As a result, the resist profile was good.

Example 8 (1) Preparation of resist composition N-ethyl-p-toluenesulfonamide was replaced with N
A resist solution was prepared in the same manner as in Example 2 except that -ethyl-1-naphthalenesulfonamide was used. (2) Resist process and evaluation A coating film sample was prepared in the same manner as in Example 1, and was exposed, developed, and evaluated. The sensitivity was 5.8 μC / cm ² , the remaining film ratio in the unexposed area was 94%, and γ was 3.0. Further, a line and space pattern of 0.5 μm was formed, and the cross section thereof was observed using a scanning electron microscope. As a result, the resist profile was good.

Example 9 (1) Preparation of resist composition The following raw materials were mixed to prepare a resist solution. 7.6 parts of novolak resin E prepared in Example 6 (1) Quinonediazide compound a prepared in Example 1 (2)
3.0 parts Phenol novolak resin prepared in Example 2 (1)
1.6 parts propylene glycol monometer ether acetate
52.8 parts N-methyl-p-toluenesulfonamide 15.0 parts N, N-dimethylformamide 20 parts Surfactant "Troysol" 366 (TOROY CH)
EMICAL) 0.03 parts.

(2) Resist Process and Evaluation Coating samples were prepared in the same manner as in Example 1, and were exposed, developed, and evaluated. The sensitivity was 5.3 μC / cm ² , the residual film ratio in the unexposed area was 83%, and γ was 2.6. Further, a line and space pattern of 0.5 μm was formed, and the cross section thereof was observed using a scanning electron microscope. As a result, the resist profile was good.

Example 10 (1) Preparation of resist composition A resist solution was prepared in the same manner as in Example 4 except that N-dodecyl-benzenesulfonamide was used instead of p-toluenesulfonanilide. (2) Resist process and evaluation A coating film sample was prepared in the same manner as in Example 1, and was exposed, developed, and evaluated. The sensitivity was 6.1 μC / cm ² , the remaining film ratio in the unexposed portion was 94%, and γ was 2.8.

Further, a 0.5 μm line-and-space pattern was formed, and its cross section was observed using a scanning electron microscope. As a result, the resist profile was good.

Comparative Example 1 (1) Preparation of Resist Composition A resist solution was prepared in the same manner as in Example 2, except that N-ethyl-p-toluenesulfonamide was not used. (2) Resist process and evaluation A coating film sample was prepared in the same manner as in Example 1, and was exposed, developed, and evaluated. The sensitivity was 16 μC / cm ² , the residual film ratio of the unexposed portion was 97%, and γ was 2.7, which was a low value of sensitivity. Further, a 0.5 μm line-and-space pattern was drawn and developed, and its cross section was observed using a scanning electron microscope. As a result, the pattern exposed portion was not completely removed, and a good pattern could not be obtained.

Comparative Example 2 (1) Preparation of Resist Composition A resist solution was prepared in the same manner as in Example 6, except that N-methyl-p-toluenesulfonamide was not used. (2) Resist process and evaluation A coating film sample was prepared in the same manner as in Example 1, and was exposed, developed, and evaluated. The sensitivity was 19 μC / cm ² , the residual film ratio of the unexposed portion was 98%, and γ was 2.5, indicating that the sensitivity was very low.
Further, a 0.5 μm line-and-space pattern was drawn and developed, and its cross section was observed using a scanning electron microscope. As a result, the pattern exposed portion was not completely removed, and a good pattern could not be obtained.

Table 1 shows the resist compositions and evaluation results of Examples 1 to 10 and Comparative Examples 1 and 2. Good results were obtained when the compound represented by the general formula (1) according to the present invention was used.

[0082]

[Table 1]

The PAC in the table is a quinonediazide compound, P
GMA is propylene glycol monoethyl ether acetate, DMF is dimethylformamide, THDMP is 1,1,2-tris (4-hydroxy-3,5-dimethylphenyl) propane, BTSA is Nn-butyl-p
-Toluenesulfonamide, ETSA is N-ethyl-p
-Toluenesulfonamide, DMBSA is N, N-dimethylbenzenesulfonamide, TSAN is p-toluenesulfonanilide, MTSA is N-methyl-p-toluenesulfonamide, ENSA is N-ethyl-1-naphthalenesulfonamide, BPPac is 2,3,4,4'-
This represents a quinonediazide compound obtained by esterifying the hydroxyl group of tetrahydroxybenzophenone by 53% with naphthoquinone-1,2-diazide-4-sulfonic acid. Although not shown in the table, all the resist compositions prepared in Examples and Comparative Examples contain 0.03 parts by weight of a surfactant "Troysol" 366.

[0084]

By using the positive type electron beam resist composition of the present invention, a high definition pattern can be formed with a low exposure dose and a short development time.

Claims (6)

[Claims] 1. The reaction of (1) an alkali-soluble resin and (2) a polyphenol compound with 1,2-naphthoquinonediazido-4-sulfonyl chloride and / or 1,2-naphthoquinonediazide-5-sulfonyl chloride as main components. A positive electron beam resist composition comprising: a quinonediazide compound obtained by the above method; and (3) at least one compound represented by the general formula (1). Embedded image (R ¹ represents an aryl group or aralkyl group having 6 to 15 carbon atoms, and R ² and R ³ represent a hydrogen atom, a linear or branched alkyl group having 1 to 15 carbon atoms, an aryl group, or an aralkyl group. R ² and R ³ may be the same or different.) Wherein R ² in the compound represented by the general formula (1)
And / or R ³ is a hydrogen atom or a group having 1 to 10 carbon atoms.
2. The positive electron beam resist composition according to claim 1, wherein the alkyl group is a straight-chain or branched alkyl group. 3. The positive electron according to claim 1, wherein the content of the compound represented by the general formula (1) is 0.05 to 10% by weight based on the total weight of the resist composition. Radiation resist composition. 4. The positive electron beam resist composition according to claim 1, wherein a novolak resin is used as the alkali-soluble resin. 5. An additive comprising a phenol nucleus in the molecule.
2. The positive electron beam resist composition according to claim 1, wherein the composition comprises from 20 to 20 compounds having a molecular weight of from 200 to 2,000. 6. A method for producing a resist pattern, wherein the positive electron beam resist composition according to claim 1 is applied onto a substrate, dried, exposed and developed.