JP2582901B2 - Positive photoresist developer for semiconductor manufacturing - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a positive photoresist developing solution for semiconductor production. More specifically, the present invention relates to a developer for a positive photoresist for manufacturing a semiconductor comprising a novolak resin and a naphthoquinonediazide-based photosensitive material, and is useful for manufacturing a semiconductor integrated circuit device and the like.

"Prior art" In recent years, the electronics industry has made remarkable progress, and with the improvement in the degree of integration of semiconductor devices and the improvement in microfabrication technology, there is a strong demand for resists used in lithography that have high resolution.

For this reason, the type of resist is shifting from a negative type to a positive type having excellent resolution.

As the positive photoresist composition, a composition containing an alkali-soluble resin and a naphthoquinonediazide compound as a photosensitive material is generally used. For example, US Pat. No. 3,666,473, US Pat. No. 4,115,128 and “Novolak-type phenol resin / naphthoquinonediazide-substituted compound”
U.S. Pat. No. 4,173,470, and the most typical composition of "Novolak resin composed of cresol-formaldehyde / trihydroxybenzophenone-1,2-naphthoquinonediazide sulfonate" is Thompson "Introduction・ Micro lithography ”
(LFThompson "Intro-duction to Microlitho-gr
aphy ") (ACS Publishing, No. 219, pp. 112-121).

Novolak resin as a binder is soluble in an alkaline aqueous solution without swelling, and is particularly useful in this application because it gives high resistance to plasma etching especially when the generated image is used as a mask for etching. It is. Further, the naphthoquinonediazide compound used in the photosensitive material itself acts as a dissolution inhibitor that reduces the alkali solubility of the novolak resin, but when decomposed by irradiation with light, generates an alkali-soluble substance and rather increases the alkali solubility of the novolak resin. It is unique in that it acts to enhance it, and is particularly useful as a photosensitive material for a positive photoresist because of its large property change to light.

From this point of view, many positive photoresists containing a novolak resin and a naphthoquinonediazide-based photosensitive material have been developed and put to practical use.

Generally, an alkaline aqueous solution is used as a developer for the naphthoquinonediazide-based positive photoresist. However, in the case of manufacturing a semiconductor device or the like, if an alkaline aqueous solution containing metal ions is used as a developer, the product characteristics are adversely affected. Therefore, a developer containing no metal ion, for example, a hydroxide of a quaternary amine such as tetramethylammonium hydroxide or trimethyl (2-hydroxyethyl) ammonium hydroxide is used.

By the way, in the development used for the manufacture of integrated circuits, a paddle development method is generally adopted. In this method, the wettability of a developer is important, and in recent years, the degree of integration of integrated circuits has increased, and It is becoming more important as the diameter increases.

However, since the developer containing no surfactant has poor wettability, the exposed portion that should be removed by development is not sufficiently removed, and a slight residue (hereinafter referred to as “film residue”) may be generated. At the same time, the surface layer of the fine resist pattern in the unexposed portion was peeled off (hereinafter referred to as "surface layer peeling"), and this surface layer was adhered to the exposed portion to cause poor development.

Further, a technique for adding a surfactant to a developer for improving wettability is known, and examples thereof include JP-A-58-57128 and JP-A-58-57128.
−158442, 60−223120, 61−167948, 62−3245
1, 62-32453 and US Pat. No. 4,374,920. However, conventionally known surfactant-containing developers are liable to form bubbles, which sometimes cause poor development and increase the temperature dependency during development, adversely affecting resist sensitivity. There were many. Furthermore, there are few film residues and those having a sufficient effect on prevention of surface delamination,
Even if it shows an effect on non-foaming properties, film residue, and surface layer peeling, the film loss in the unexposed area is large, the dimensional accuracy is poor, and the resolution is low because the cross-sectional shape of the resist tends to be trapezoidal Most of what was done.

As one method for improving the non-foaming property, a technique of adding a hydrophilic organic solvent to a developer is disclosed in JP-A-49-91177 and JP-A-49-91177.
9-182444, 60-158461, 60-241051, 61-3904
1, 61-259523, 61-232453, etc., the addition of a small amount has no effect on non-foaming properties, film residue, peeling of the surface layer, etc. However, there has been a problem that the amount of film reduction of the film becomes large and the dimensional accuracy is deteriorated.

Further, a non-foaming developer to which an oxyalkylene group-containing organopolysiloxane is added is disclosed in US Pat.
1. Although disclosed in Japanese Patent Application Laid-Open No. 62-73270, this product alone has no effect on surface layer peeling.

Furthermore, even if a conventional surfactant and an organic solvent are used in combination, they do not satisfy all requirements such as non-foaming properties, film residue, surface layer peeling and film loss prevention.

It is also possible to add a nonionic surfactant of a polyoxyethylene condensation type of a trihydric or higher alcohol.
Although disclosed in -175738, it has no effect on non-foaming properties.

“Means for Solving the Problems” As a result of intensive studies, the present inventors have found that an alkali-soluble resin and a specific surfactant (non-initiating agent) can be added to a conventional positive photoresist developing solution for semiconductor production. Foaming agent) to solve the above problem,
The present invention has been completed. That is, the object of the present invention is:
It is characterized in that an organic metal surfactant such as a polyoxyalkylene group-containing organopolysiloxane and an alkali-soluble resin such as a novolak resin are added to a positive photoresist developing solution for semiconductor production containing a basic compound as a main component. This has been achieved with a positive photoresist developer for semiconductor manufacturing.

Developers containing a basic compound as the main component in the present invention include, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium phosphate, sodium metasilicate, inorganic alkalis such as aqueous ammonia,
Primary amines such as ethylamine and n-propylamine;
Secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcoholamines such as dimethylethanolamine and triethanolamine; amides such as formamide and acetamide; tetramethylammonium hydroxy , Trimethyl (2-hydroxyethyl) ammonium hydroxide, tetraethylammonium hydroxide, tributylmethylammonium hydroxide, tetraethanolammonium hydroxide, methyltriethanolammonium hydroxide, benzylmethyldiethanolammonium hydroxide, benzyldimethylethanolammonium hydroxide , Benzyltriethanolammonium hydroxide, tetrapropylammonium hydroxide Rokishido, quaternary ammonium salts such as tetrabutylammonium hydroxide, pyrrole,
There are aqueous solutions of alkalis such as cyclic amines such as piperidine.

When the use of a metal-containing developer becomes a problem among these, it is preferable to use an aqueous solution of a quaternary ammonium salt or a cyclic amine, and particularly preferable are tetramethylammonium hydroxide and trimethyl (2- (Hydroxyethyl) ammonium hydroxide.

These may be used alone or in combination of two or more. The concentration is 1% by weight.
To 10% by weight, preferably 1.5% to 5.5% by weight.

Examples of the polyoxyalkylene group-containing organopolysiloxane (organometallic surfactant) of the present invention to be added to a positive photoresist developer for semiconductor production include surfactant handbook (published by Kogaku Tosho Co., Ltd.) and Chemical Industry (1966), Vol. 19, p. 147. The following are some specific examples. And the like. The R of these compounds
And R 'each represent a hydrogen atom or an alkyl or substituted alkyl group containing from 1 to 25 carbon atoms. m, n, l is 1
And p and q represent 1 to 50. Oxyalkylene group-containing organopolysiloxanes, in addition to the compounds shown in the above specific examples, for example, JP-A-51-10188, JP-A-54-149388,
56-139107, 56-139108, 56-136609, Tokiko Sho 54
Compounds described in JP-A-43015, US Pat. Nos. 3,339,863 and 3,250,727 can also be used.

The addition amount of these water-soluble organometallic surfactants is 0.001 to 0.5% by weight based on the developer, more preferably,
0.003 to 0.3% by weight.

Examples of the alkali-soluble resin of the present invention to be added to the developer for a positive photoresist for semiconductor production include a novolak resin, an acetone-pyrogallol resin, polyhydroxystyrene and derivatives thereof.

Among them, a novolak resin is particularly preferable, and is obtained by subjecting a predetermined monomer as a main component to addition condensation with an aldehyde in the presence of an acidic catalyst.

Examples of the predetermined monomer include cresols such as phenol, m-cresol, p-cresol, and o-cresol; xylenols such as 2,5-xylenol, 3,5-xylenol, 3,4-xylenol, and 2,3-xylenol Kind,
alkylphenols such as m-ethylphenol, p-ethylphenol, o-ethylphenol, pt-butylphenol, p-methoxyphenol, m-methoxyphenol, 3,5-dimethoxyphenol, 2-methoxy-4- Alkoxyphenols such as methylphenol, m-ethoxyphenol, p-ethoxyphenol, m-propoxyphenol, p-propoxyphenol, m-butoxyphenol, p-butoxyphenol, and bisalkyls such as 2-methyl-4-isopropylphenol Phenols, m-chlorophenol, p-chlorophenol, o-chlorophenol, dihydroxybiphenyl, bisphenol A, phenylphenol,
Hydroxy aromatic compounds such as resorcinol and naphthol can be used alone or in combination of two or more, but are not limited thereto.

Examples of the aldehydes include 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, furfural, chloroacetaldehyde and their acetal forms, such as chloroacetaldehyde diethylacetal, can be used, but among these, formaldehyde is preferred.

These aldehydes are used alone or in combination of two or more.

As the acidic catalyst, hydrochloric acid, sulfuric acid, formic acid, acetic acid, oxalic acid and the like can be used.

The weight average molecular weight of the thus obtained novolak resin is preferably in the range of 500 to 50,000. If it is less than 500, the amount of film reduction in the unexposed resist becomes large,
If it exceeds 0, the effect on surface delamination is reduced. Particularly preferred is the range from 700 to 20,000.

Here, the weight average molecular weight is defined as a value in terms of polystyrene of gel permeation chromatography.

In the developer of the present invention, additives commonly used in conventional developers can be used alone or in combination. For example, a cationic surfactant or a nonionic surfactant may be used in combination in order to improve the dissolution selectivity between the exposed part and the unexposed part of the positive photoresist film,
In order to prevent film residue, surface layer peeling, and foaming, a synergistic effect can be exhibited by combining with the following surfactants, hydrophilic solvents, defoamers, and the like.

As cationic surfactants, quaternary ammonium salts, pyridinium salts and picolinium salts are mainly used. For example, as quaternary ammonium salts, tributylmethylammonium chloride, triamylmethylammonium chloride, trihexylmethylammonium chloride , Trimethylixadecyl ammonium chloride,
And trimethyldodecylammonium chloride.

Examples of the pyridinium salt include dodecylpyridinium chloride, and examples of the picolinium salt include dodecylpicolinium chloride.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, and polyoxyethylene nonyl phenyl ether. Polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, etc. Sorbitan aliphatic esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxy Chile Nso sorbitan monostearate, polyoxyethylene sorbitan trioleate,
There are polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan tristearate.

Furthermore, 1,1,1-ethanetriol, 1,1,1-propanetriol, 1,2,3-propanetriol, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,3 , 3-Butanetriol, 1,2,3-pentanetriol, 1,2,5-pentanetriol, 1,3,4-pentanetriol, 1,3,5-
Pentanetriol, 2,3,4-pentanetriol, trimethylolethane, 1,2,3-hexanetriol, 1,
2,6-hexanetriol, 1,3,5-hexanetriol, 2,3,4-hexanetriol, 2,3,5-hexanetriol, trimethylolpropane, 1,2,3-heptanetriol, 1,3 1,7-heptanetriol, 1,4,5-heptanetriol, 1,4,7-heptanetriol, 2,3,4-heptanetriol, threitol, erythritol, pentaneerythritol, 1,2,3,4-hexane Polyoxyalkylenes of trihydric or tetrahydric alcohols such as tetrol, 1,3,5,6-hexane tetrol, 1,3,4,6-hexane tetrol, and 2,3,4,5-hexane tetrol And condensates. The addition amount of these cationic and nonionic surfactants is preferably in the range of 10 to 10,000 ppm, and particularly preferably in the range of 100 to 5000 ppm. These surfactants may be added alone or in some combination.

These conventionally used additives can be added in the range of 1 to 30% by weight, preferably 1 to 5% by weight, based on the surfactant of the present invention.

Examples of the hydrophilic solvent include methanol, ethanol, n-propanol, isopropanol, secondary butanol, tertiary butanol, n-amyl alcohol, isoamyl alcohol, activated amyl alcohol, secondary amyl alcohol, 3-pentanol, and tertiary amyl Monohydric alcohols such as alcohol, acetone, methyl ethyl ketone,
Ketones such as diethyl ketone, methyl isobutyl ketone and cyclohexanone; cyclic ethers such as tetrahydrofuran, dioxane, trimethylene oxide and butylene oxide; acetates such as ethyl acetate and butyl acetate; ethylene glycol monomethyl ether; ethylene glycol monoethyl ether Glycol glycol ethers such as ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether and diethylene glycol dimethyl ether; cellosolve esters such as methyl cellosolve acetate and ethyl cellosolve acetate; monooxycarboxylic acids such as methyl lactate and ethyl lactate Acid esters and the like.

These hydrophilic solvents are used in an amount of 0.
It can be added in the range of 05 to 30% by weight, preferably 0.1 to 5% by weight.

An additive can be added to the developer of the present invention to promote the dissolution of the positive photoresist composition for semiconductor production in the developer. Examples of the additive include a polyhydroxy compound, and preferred polyhydroxy compounds include:
For example, hydroquinone, resorcinol, catechol,
Pyrogallol, 2-methylresorcylaire, phloroglucin, 1,2,4-trihydroxybenzene, 6,7-dihydroxy-4-methylcoumarin, methylenebis-p-cresol, 2,3,4-trihydroxybenzophenone, 2,4,4 ′
-Trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,4-trihydroxy-2'-
Methylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,4,6,3', 4'-pentahydroxy Benzophenone, 2,3,4,2 ', 4'-pentahydroxybenzophenone, 2,3,4,2', 5'-pentahydroxybenzophenone, 2,4,6,3 ', 4 Polyhydroxybenzophenones such as', 5'-hexahydroxybenzophenone, 2,3,4,3 ', 4', 5'-hexahydroxybenzophenone, and 2,3,4-
Polyhydroxyphenylalkyl ketones such as trihydroxyacetophenone, 2,3,4-trihydroxyphenylbentyl ketone, and 2,3,4-trihydroxyphenylhexyl ketone; bis (2,4-dihydroxyphenyl); Enyl) methane, bis (2,3,4-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) propane
1, bis (2,3,4-trihydroxyphenyl) propane-1, bis ((poly) hydroxyphenyl) alkanes such as nordihydroguaiaretic acid, propyl 3,4,5-trihydroxybenzoate Polyhydroxybenzoic esters such as phenyl 2,3,4-trihydroxybenzoate and phenyl 3,4,5-trihydroxybenzoate; bis (2,
3,4-trihydroxybenzoyl) methane, bis (3-
Bis (polyhydroxybenzoyl) such as acetyl-4,5,6-trihydroxyphenyl) -methane, bis (2,3,4-trihydroxybenzoyl) benzene and bis (2,4,6-trihydroxybenzoyl) benzene ) Alkanes or bis (polyhydroxybenzoyl) aryls, alkylene-di (polyhydroxybenzoates) such as ethylene glycol-di (3,5-dihydroxybenzoate), ethylene glycol-di (3,4,5-trihydroxybenzoate) , 2,3,4-biphenyltriol, 3,
4,5-biphenyltriol, 3,5,3 ', 5'-biphenyltetrol, 2,4,2', 4'-biphenyltetrol, 2,
4,6,3 ', 5'-biphenylbenthol, 2,4,6,2', 4 ',
Polyhydroxybiphenyls such as 6'-biphenylhexol, 2,3,4,2 ', 3', 4'-biphenylhexol, 4,
Bis (polyhydroxy) sulfides such as 4'-thiobis (1,3-dihydroxy) benzene, bis (polyhydroxyphenyl) ethers of 2,2 ', 4,4'-tetrahydroxydiphenyl ether, 2 Bis (polyhydroxyphenyl) sulfoxides such as 2,2 ', 4,4'-tetrahydroxydiphenylsulfoxide and bis (polyhydroxyphenyl) such as 2,2', 4,4'-diphenylsulfon )
Sulfones, 4,4 ', 3 ", 4" -tetrahydroxy-3,
5,3 ', 5'-tetramethyltriphenylmethane, 4,4',
2 ", 3", 4 "-pentahydroxy-3,5,3 ', 5'-tetramethyltriphenylmethane, 2,3,4,2', 3 ', 4'-hexahydroxy-5,5' -Diacetyltriphenylmethane, 2,3,4,2 ', 3', 4 ', 3 ", 4" -octahydroxy-
5,5'-diacetyltriphenylmethane, 2,4,6,2 ',
Polyhydroxytriphenylmethanes such as 4 ', 6'-hexahydroxy-5,5'-dipropionyltriphenylmethane;3,3,3',3'-tetramethyl-1,1'-spiropy-
Indan-5,6,5 ', 6'-tetrol, 3,3,3', 3'-tetramethyl-1,1'-spiropyindane-5,6,7,5 ',
6 ', 7'-hexol, 3,3,3', 3'-tetramethyl-
1,1'-spiropy-indane-4,5,6,4 ', 5', 6'-hexol, 3,3,3 ', 3'-tetramethyl-1,1'-spiropy-indane-4, Polyhydroxyspiropyindanes such as 5,6,5 ', 6', 7'-hexol, 3,3-bis (dihydroxyphenyl) phthalide, 3,3-bis (2,3,4-trihydroxy Phenyl) phthalide, 3 ', 4', 5 ', 6'-
Polyhydroxyphthalides such as tetrahydroxyspiro [phthalide-3,9'-xanthene], or morin;
Flavono dyes such as quercetin and rutin can be used.

Those skilled in the art can appropriately select the amount of the polyhydroxy compound to be added.

[Effects of the Invention] The developer of the present invention can provide a resist pattern having a high residual film ratio without causing surface layer peeling or film residue during development of a positive photoresist in semiconductor production.

Further, since the developer of the present invention has good wettability to the resist, there is no waste of the developer, and good development can be performed even when an ultrafine pattern is formed because of good permeability,
A clear resist pattern can be obtained.

Further, since the developer of the present invention has excellent non-foaming properties, it does not induce poor development.

"Examples" Examples of the present invention will be described below, but the present invention is not limited thereto. In addition,% indicates weight% unless otherwise specified.

Examples 1 to 9 and Comparative Examples 1 to 6 40 g of m-cresol, 60 g of p-cresol, 49 g of 37% aqueous solution of formalin and 0.13 g of oxalic acid were charged into a three-necked flask, and the temperature was raised to 100 ° C. while stirring. Allowed to react for hours.

Thereafter, the temperature was raised to 200 ° C., and the pressure was gradually reduced to 5 mmHg to remove water, unreacted monomers, formaldehyde, oxalic acid, and the like. Next, the molten alkali-soluble novolak resin was returned to room temperature and recovered. The obtained novolak resin had a weight average molecular weight of 7,100 (in terms of polystyrene).

Next, 2,3,4,
1.25 g of 1,2-naphthoquinonediazide-5-sulfonic acid ester of 4'-tetrahydroxybenzophenone was added,
It was dissolved in 15 g of ethyl cellosolve acetate and filtered using a 0.2 μm microfilter to prepare a photoresist composition. This photoresist composition was applied to a 4-inch silicon wafer using a spinner, dried in a convection oven under a nitrogen atmosphere at 90 ° C. for 30 minutes, and dried at a film pressure of 1.5 μm.
A resist film was obtained. This film was exposed using a reduction projection exposure apparatus (NSR1505G manufactured by Nikon Corporation), and then heated at 23 ° C. using a developer prepared by adding an additive shown in Table 1 to a 2.38% aqueous solution of tetramethylammonium hydroxide. For 1 minute, washed with water for 30 seconds and dried.

The resist pattern on the silicon wafer thus obtained was observed with a scanning electron microscope, and the sensitivity, resolution, developability (surface layer peeling, film residue) and residual film ratio were measured. Table 2 shows the results.

In addition, as a comparative example, the results when the additives other than the additives of the present invention shown in Table 1 were added and when the additives were not added are also shown in Table 2.

The sensitivity was defined as the reciprocal of the exposure amount for reproducing a mask pattern of 2.0 μm, and was shown as a relative value of the sensitivity of Comparative Example 1.

 The residual film ratio was expressed as a percentage of the ratio of unexposed portions before and after development.

Regarding surface layer peeling and film residue, ○ indicates a case where no observation was observed, favorable, × indicates a case where many were observed, and Δ indicates a case where a little was observed.

Regarding the wettability, ○ indicates that there is no residual wetting of the developer.
X represents the case where the residual wetness occurs.

 At this time, the developer was 13 cc.

Regarding non-foaming properties, ○ indicates that no bubbles were generated in the developer, X indicates that bubbles were generated, and Δ indicates that some were generated.

As can be seen from Table 2, the developer of the present invention was excellent in the residual film ratio, did not cause surface layer peeling or film residue, and was excellent in both wettability and non-foaming properties.

Claims (3)

(57) [Claims] 1. A positive photoresist for semiconductor production, comprising adding an alkali-soluble resin and an oxyalkylene group-containing organosiloxane to a developer for a positive photoresist for semiconductor production containing a basic compound as a main component. Developer for resist. 2. The semiconductor manufacturing method according to claim 1, wherein said basic compound is at least one selected from tetramethylammonium hydroxide and trimethyl (2-hydroxyethyl) ammonium hydroxide. For positive photoresist. 3. The method according to claim 1, wherein the alkali-soluble resin is a novolak resin, an acetone-pyrogallol resin,
A developer for a positive photoresist for semiconductor production, which is at least one selected from polyhydroxystyrene and derivatives thereof.