JPH0362034A - Developer for positive type photoresist - Google Patents

Abstract

PURPOSE:To prevent the occurrence of film residue and the exfoliation of a surface layer at the time of development by adding an alkali-soluble resin and a specified surfactant to a developer for a positive type photoresist. CONSTITUTION:A water soluble organometallic surfactant such as organopolysiloxane contg. a polyoxyalkylene group and an alkali-soluble resin such as novolak resin are added to a developer for a positive type photoresist contg. a basic compd. as an essential component. The amt. of the surfactant added is 0.001-0.5wt.%, preferably 0.003-0.3wt.% of the amt. of the developer. The wt. average mol.wt. of the novolak resin is preferably 500-50,000. The exfoliation of a surface layer and the occurrence of film residue are prevented at the time of developing a positive type photoresist and a resist pattern having a high film remaining rate can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a developer for positive type photoresists. In detail, it relates to a positive photoresist developer consisting of a novolac resin and a 7-toki/nonanod-based photosensitive material, and is used for cattle-specific integrated circuit elements, etc. ! It is useful for the deceased.

``American technology'' The electronic industry has made significant progress in recent years, and with the improvement in the integration density of cattle-specific equipment and the improvement of microfabrication technology, there is a strong demand for high-resolution Renosto used in ring graphs. ing.

For this reason, the type of resist is also shifting from winter-type resists to positive-type resists with excellent resolution.

As a positive type photoresist composition, a composition containing an alkali-soluble resin and a photosensitive material, ie, a monoazide compound, is generally used. For example, USP No. 3,666,473, USP No.
, 115, 128 and LISP-4, 173, 470
``Cresol'' is the most typical example.
Formaldehyde/borac resin/trihydroxybenzo-7-ene-1,2-dianodianodosulfonic acid ester" is an example of Thompson's "Introduction to Microlithography-J (
L, F, Thompson rIntro -
duction to Microlith.

gr aphy J) (AC3 Publishing, N
o, No. 219, P112-121).

Novolac resins as binders are particularly suitable for this application because they can be dissolved in alkaline aqueous solutions without leaching and also provide high resistance to plasma etching, especially when the resulting image is used as an etching mask. Useful. In addition, the 7-toquinone diazide compound used in photosensitive materials itself acts as a dissolution inhibitor that reduces the alkali solubility of the borac resin, but when it is decomposed by light irradiation, it produces alkali-soluble substances and rather
It is different from vf in that it works to increase the alkali solubility of borac resin, and because of its large property change in response to light, it is particularly useful as a positive type 7 otrenost photosensitive material.

From this point of view, many positive photoresists containing a borac resin and a 7-toquinone diacid photosensitive material have been developed and put into practical use.

An alkaline aqueous solution is usually used as a developer for positive photoresists based on diazide, but when manufacturing semiconductor devices etc., an alkaline aqueous solution containing metal ions is used as the developer. Since this adversely affects product properties, developers that do not contain metal ions, such as 4a amine hydroxides such as tetramethylammonium hydroxide and trimethyl(2-hydroxyethyl)ammonium hydroxide, are used.

By the way, the puddle development method is generally used for the development used in the GL fabrication of integrated circuits, but wettability of the developer is important in this method, and in recent years, the degree of integration of integrated circuits has increased, and wafer This is becoming even more important as the diameter becomes larger.

However, due to the poor wettability of a developer that does not contain a surfactant, the exposed areas that should be removed by final development are not sufficiently removed, leaving a slight residue (hereinafter referred to as "film residue").
or peeling of the surface layer of the fine Rennost pattern in the unexposed area (hereinafter referred to as "surface layer peeling"), and this surface layer may adhere to the exposed area, resulting in poor development.

In addition, the technique of adding a surfactant to the developer to increase wettability is known, for example, vfr4R
28, 60-158442, 60-223120,
61-167948, 62-32451, 62-
32453, USP 4374920, etc. However, conventionally known developing solutions containing surfactants tend to generate bubbles, and these bubbles can sometimes cause poor development and increase temperature dependence during development, which can have a negative impact on Lennost sensitivity. There were many. Furthermore, there are few products that are sufficiently effective in preventing film residue and surface layer peeling, and even if they are effective in preventing foaming, film residue, and surface layer peeling, the film loss in unexposed areas is large. In most cases, the dimensional accuracy deteriorates and the cross-sectional shape of the resist tends to become trapezoidal, resulting in a decrease in resolution.

As a method for improving the non-foaming property, a technique of adding a hydrophilic organic solvent to the developing solution was introduced in vfN4 1977-911.
77, 59-182444, 60-158461,
60-241051, 6139041, 61-2
59523, 61232453, etc., but if the amount added is small, it is not effective against non-foaming properties, film residue, surface layer peeling, etc., and if it is added in a large amount, the amount of film loss in the unexposed area becomes large. There was a problem that the dimensional accuracy deteriorated.

In addition, a non-foaming developer containing oxyalkylene group-containing Olff/polysiloxane is available under USP 3,545,970.
, BP1382901, and JP-A-62-73270, but this alone has no effect on surface/I peeling.

Furthermore, even when a conventional surfactant and an organic solvent are used in combination, all of the properties such as non-foaming property, film residue, surface layer peeling, and prevention of film thinning are not satisfied.

In addition, it is recommended to add a nonionic surfactant of polyoxyethylene condensation type of trihydric or higher alcohol.
-175738, but this has no effect on non-foaming properties.

"Means for Solving the Problems" As a result of extensive studies, the inventors of the present invention have added an alkali-soluble resin and a specific surfactant (non-foaming agent) to the conventional positive photoresist developer. It was discovered that the above-mentioned problems could be solved by adding the above, and the present invention was completed. That is, the object of the present invention is to add an organic surfactant such as a polyoxyalkylene group-containing organopolysimixane and an alkali-soluble resin such as a novolac resin to a positive type 7 otorenest developer containing a basic compound as a main component. 9 was achieved in a positive photoresist developer with VF characteristics.

In the present invention, the developer containing a basic compound as a main component includes, for example, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium phosphate, sodium metasilicate, aqueous ammonia, ethylamine, Primary amines such as n-propylamine, tertiary amines such as noethylamine, non-n-butylamine, tertiary amines such as triethylamine, methylnoethylamine, alcohol amines such as nomethylethylamine, triethylamine, etc. Amides such as formamide and acetamide, tetramethylammonium hydroxide, tri/tyl(2-hydroxyethyl)ammonium hydroxide, tetraethylammonium hydroxide, tributylmethylammonium hydroxide, tetraethanolammonium hydroxide, methyltriethyl Ammonium hydroxide, benzyl methyl ethyl ammonium hydroxide, pennornomethyl ethyl ammonium hydroxide, pennortriethanol ammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc. Examples include aqueous solutions of alkalis such as quaternary ammonium salts, virol, cyclic amines such as piperidine, etc.

Among these, when the use of metal-containing developers becomes a problem, it is preferable to use aqueous solutions of quaternary ammonium salts or cyclic amines, and particularly preferable are tetramethylammonium hydroxide and trimethyl(2- Hydroxyethyl> ammonium hydroxide.

Each of these may be used alone, or 2! IIi or more may be used in combination. Further, its concentration is 1% by weight to 10% by weight, preferably 1.5% by weight to 5.5% by weight.

The polyoxyalkylene group-containing Ol7y/polysiloxane (
There are 8! For metal surfactants, see Surfactant Handbook (published by Kogaku Tosho Co., Ltd.) and Kagaku Kogyo (1966 Hitsuji).
It is described in detail in Volume 19, page 147. Hereinafter, to give some specific examples, compounds such as the following can be mentioned. R of these compounds
and R' each represents a hydrogen atom or an alkyl group or substituted alkyl group containing 1 to 25 carbon atoms e III
tntl is 1-5, and 9yQ is 1-50. In addition to the compounds shown in the above specific examples, the oxyalkylene group-containing organopolysiloxanes include
1-10188, 54-149388, 5 (3-1
39107, 56-139108, 56-1366
09, Special Publication No. 54-43015, USP3233986
, 3250727 and the like can also be used.

The amount of these water-soluble organometallic surfactants to be added is from o, ooi to 0.5% by weight, more preferably from 0.003 to 0.3% by weight, based on the developer.

Examples of the alkali-soluble resin of the present invention added to the positive type 7 otrenost developer include /borac resin, acetone-pyrogallol resin, polyhydroxystyrene, and derivatives thereof.

Among these, Borac resin is preferred, and is obtained by addition-condensing a predetermined moamer as a main component with an aldehyde in the presence of an acidic catalyst.

Examples of the predetermined moamers include cresols such as 7-er/-l, shin-cresol, p-cresol, and 0-cresol;
2,5-xylene/-l, 3,5-xylene/-l, 3,4
-xylenol such as xylene 7-yl, 2,3-xylene/-l, m-ethylphenol, p-ethyl 7-yl,
0-Ethylpheno-/L,,p-t-)f7/
Alkylphenols such as p-7 toxyphenol, -1methoxy 7-ol, 3,5-nomethoxy 7-ol, 2-methoxy-4-methyl 7-ol, and ethoxyphenol , p-ethoxy 7 ethyl/-70
Alkoxyphenols such as boxyphenol, p-propoxy phenol, m-butoxyphenol, p-butoxyphenol, bisalkyl phenol such as 2-methyl-4-isopropylphenol, chlorophenol, Hydroxy aromatic compounds such as p-chloro7el, 0-chlorophenol, dihydroxybiphenyl, bis7eral A1 phenylphenol, resorcinol, naphthol, etc. are used alone or in combination of two or more. However, it is not limited to these.

Examples of aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde,
a-phenylpropylaldehyde, β-phenylpropylaldehyde, O-hydroxybenzaldehyde,
-monohydroxybenzaldehyde, p-hydroxybenzaldehyde, 0-chlorobenzaldehyde, -monochlorobenzaldehyde, p-chlorobenzaldehyde, 0
-nitrobenzaldehyde, -m=trobenzaldehyde, p-nitrobenzaldehyde, 0-methylbenzaldehyde, -monomethylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, p
n-Butylbenzaldehyde, furfural, taloloacetaldehyde and acetals thereof, such as chloroacetaldehyde noethyl acetal, etc. can be used, but among these, formaldehyde is preferably used.

These aldehydes may be used alone or in combination of two or more.

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

The weight average molecular weight of the novolac resin thus obtained is:
It is preferably in the range of 500 to 5oooo. 50
If it is less than 0, the amount of film loss in unexposed areas of the resist will increase, and if it exceeds 5oooo, the effect on surface layer peeling will be reduced. Particularly preferred is a range of 700 to 20,000.

Here, the weight average molecular weight is defined as a polystyrene equivalent value determined by del permeation chromatography.

In the developing solution of the present invention, additives commonly used in conventional developing solutions can be used alone or in combination. In order to improve the performance, a cationic surfactant or a nonionic surfactant may be used in combination, or the following surfactants, hydrophilic solvents, and antifoaming agents may be used to prevent film residue, surface layer peeling, and foaming. It can also be combined with others to create a synergistic effect.

As cationic surfactants, quaternary ammonium salts, pyridinium salts, and picolinium salts are mainly used.
For example, quaternary ammonium salts include tributylmethylammonium chloride, triamylmethylammonium chloride, trihexylmethylammonium chloride, trimethylixadicylammonium chloride, trimethyldodecyl ammonium chloride, and the like.

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

Examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, and polyoxyethylene cetyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene nonylphenyl ether. Polyoxyethylene alkyl allyl ethers, polyoxyethylene/polyoxypropylene block polymers, sorbitan monolaurate, sorbitan monolaurate, sorbitan monostearate, sorbitan monoester, sorbitan trioleate, sorbitan trioleate Sorbitan fatty acid esters such as stearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan mo/palmitate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, etc. Polyoxyethylene sorbitan fatty acid esters, etc.

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. (5-hexanetriol, 1,3,5-
Hexanetriol, 2.3,4-hexanetriol, 2,3.5-hexanetriol, trimethylolethane, 1゜2.3-hebutanetriol, 1.3.7-
Hebutanetriol, 1,4.5-hebutanetriol, 1.4,7-heptanetriol, 2,3,4-hebutanetriol, threitol, erythritol, pentaerythritol, 1,2,3.4-hexane Tetrol, 1,3,5.6-hexanetetrol, 1.3.4
．． Examples include polyoxyalkylene condensates of trihydric or tetrahydric alcohols such as 6-hexanetetrol and 2,3,4.5-hexanetetrol. The amount of these cationic and nonionic surfactants added is 10 to 10,000 pp-
The range is preferably 100 to 5000, particularly preferably 100 to 5000.
It is in the ppm range. These surfactants may be added alone or in combination.

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

Examples of hydrophilic solvents include methanol, ethanol,
■-proper/-ol, improper tool, sec-butanol, tertiary-butanol, n-amyl alcohol, isoamyl alcohol, activated amyl alcohol, 27th mil alcohol, 3-pentanol, 37th mil Alcohol, etc. 1
Hydrolic alcohols, ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl imbutyl ketone, and cyclohexanone, cyclic ethers such as tetrahydro7rane, nooxane, trimethylene oxide, butylene oxide, and acetic acid esters such as ethyl acetate and butyl acetate. Glyfur alkyl ethers such as , ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, noethylene glycol dimethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate Examples include cellosolve esters such as methyl lactate, monooxycarboxylic acid esters such as ethyl lactate, and the like.

These hydrophilic solvents have a 0.0.
It can be added in an amount of 0.05 to 30% by weight, preferably 0.1 to 5% by weight.

Additives can be added to the developer of the present invention in order to promote dissolution of the positive photoresist composition in the developer. Additives include polyhydroxy compounds,
Preferred polyhydroxy compounds include, for example, hydroquinone, resorcinol, catechol, pyrogallol, 2
-Methyl resorcinol, 70 loglucin, 1,2.4
-) lyhydroxybenzene, 6,7-dihydroxy-4
-Methylcoumarin, methylenebis-p-cresol, 2
．． 3.4-) Lyhydroxybenzophenone, 2°4.4
'-) Lihydroxybenzophenone, 2.4゜6-trihydroxybenzophenone, 2,3.4-trihydroxy-2'-methylbenzo7ene, 2.3,4,4'-
Tetrahydroxybenzophenone, 2.2°, 4.4'
-tetrahydroxybenzo7en/ene, 2,4,6,3'
, 4'-pentahydroxybenzo7en/ene, 2,3,4
,2°,4°-pentahydroxybenzo7ene/ene,2,
3,4.2',5'-pentahydroxybenzo7ene, 2,4,6.3',4',5'hexahydroxybenzo7ene, 2,3,4,3'4 Polyhydroxybenzophenones such as ',5'-hexahydroxybenzo7ene/2,3.4-)lyhydroxyacetophenone, 2
, 3.4-) dihydroxyphenylbentyl ketone, 2
, 3.4-) Polyhydroxyphenylalkyl ketones such as dihydroxyphenylhexyl ketone, bis(2°4-dihydroxyphenyl)methane, bis(2°3.4)
-) dihydroxyphenyl>methane, bis(2,4-dihydroxyphenyl)propane-1, bis(2,3,4
-trihydroxyphenyl)propane-1, bis((poly)hydroxyphenyl>alkanes such as nordihydroguaiaretic acid, 3.4.5-)propyl hydroxybenzoate, 2゜3.4-)rihydroxy Polyhydroxybenzoic acid esters such as phenyl benzoate, phenyl 3,4゜5-trihydroxybenzoate, bis(2,3,
4-trihydroxybenzoyl)methane, bis(3-acetyl-4,5,6-trihydroxyphenyl)-methane, bis(2,3,4-trihydroxybenzoyl)
Bis(polyhydroxybenzoyl) such as benzene, bis(2,4,(3-)lyhydroxybenzoyl)benzene
Alkanes or bis(polyhydroxybenzoyl)aryls, ethylene glycol (3,5-dihydroxybenzoate), ethylene glycol (3,4,5
-) dihydroxybenzoate), etc.
polyhydroxybenzoates), 2,3.4-biphenyltriol, 3,4.5-biphenyltriol,
3,5.3', 5'-biphenyltetrol, 2,4°2', 4'-biphenyltetrol, 2,4,6.3'
5゛-Biphenylbentol, 2,4,6,2'', 4゛6゛-Biphenylhexol, 2.3.4.2', 3
Polyhydroxybiphenyls such as '4'-biphenylhexol, bis(polyhydroxy) sulfides such as 4,4'-thiobis(1,3-dihydroxy)benzene, 2,2',4,4'-tetrahydroxyno Bis(polyhydroxyphenyl) ethers such as phenyl ether, bis(polyhydroxyphenyl)sulf 7 oxides such as 2.2', 4.4'-tetrahydroxynophenyl sulf 7 oxide, 2°t) l, 4, Bis(polyhydroxyphenyl) such as 41-diphenylsulfone
Sulfone M, 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'-noacetyltriphenylmethane, 2.3
．． 4.2',3',4'3'',4''-octahydroxy-5,5'-noacetyltriphenylmethane, 2,4,6.2',4',6'-hexahydroxy-5 , 5″-polyhydroxytriphenylmethane such as noprobionyltriphenylmethane, 3.3.3′,
3′-tetramethyl-1゜1゛-spirobee bean-5,6,5′,6′-tetrol, 3,3.3′,
3'-tetramethyl-1,1'-spirobee green bean-
5, 6, 7, 5', 6', 7' all, 3.
3.3',3'-tetramethyl-1.1'-spirobin bean-4,5,6,4',5'6'-hequinol,3,3.3',3'-tetramethyl-1, 1゛-
Spirobee bean-4,5,6,5'6°, 7'-hequinol and other polyhydroxysubibe beans,
3,3-bis(dihydroxyphenyl)7thalide, 3,
Polyhydroxy 7-thallides such as 3-bis(2,3,4-trihydroxyphenyl) 7-thallide, 3', 4', 5.6'-tetrahydroxyspiro[7-thallido 3'9'-xanthine J, or 7 lab/pigments such as morin, keratin, rutin, etc. can be used.

The amount of the polyhydroxy compound added can be appropriately selected by those skilled in the art.

"Effects of the Invention" The developer of the present invention does not cause surface layer peeling or film residue during development of a positive photoresist, and can obtain a Renost pattern with a high residual film rate.

In addition, the developer of the present invention has good wettability to the resist, so there is no wastage of the developer, and since it has good permeability, good development can be performed even when creating ultra-fine patterns, and clear resist patterns can be obtained. Obtainable.

Furthermore, since the developer of the present invention has excellent non-foaming properties,
It does not cause development defects.

"Examples" Examples of the present invention are shown below, but the present invention is not limited thereto. Unless otherwise specified, % is
Indicates weight %.

Examples 1 to 9 and Comparative Examples 1 to 6 -1-cresol 40g% p-cresol 60g 137%
Three Lof flasks were charged with 49 g of formalin aqueous solution and 0.13 g of chef's acid, heated to 100° C. with stirring, and reacted for 15 hours.

After that, the temperature was increased to 200℃ and gradually 5tnIIIH
Water, unreacted monomers, formaldehyde, oxalic acid, and the like were removed by reducing the pressure to 1.5 g. The molten alkali-soluble/borac resin was then returned to room temperature and collected. The obtained novolac resin had a weight average molecular weight of 117,100 (polystyrene exchanged IT).

Next, 2.3 g of this novolac resin was added as a photosensitizer.
1.2- of 4.4'-tetrahydroxybenzo7ene
Su7toki/Nnoanodo 5-sulfonic acid ester 1.2
Add 5 g, dissolve in 15 g of ethyl cellosolve acetate, filter using a 0.2μ microfilter,
A photoresist composition was prepared. This photoresist composition was applied to a 4-inch silicon wafer using a spinner and heated to 90”C1 in a convection oven under nitrogen $Bλ.
After drying for 30 minutes, a Renost film with a film thickness of 1.5 μω was obtained.

For this film, we used a reduction projection exposure device made by Kon Co., Ltd. N5R1505G.
) and then paddle developed for 1 minute at 23°C using a developer prepared by adding the additives shown in Table 1 to a 2.38% aqueous solution of tetramethylammonium hydroxide, followed by 30 seconds. Washed with water and dried.

The Rennost pattern thus obtained on the silicon wafer was observed using a scanning electron microscope, and the sensitivity, resolution,
Developability (layer peeling and film residue in 2) and film remaining rate were measured.

The results are shown in Table-2.

As comparative examples, Table 2 also shows the results when additives other than the additives of the present invention shown in Table 1 were added, and when no additives were added.

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

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

Regarding surface layer peeling and film residue, ◯ indicates good condition with no observed, × indicates a large amount observed, and Δ indicates a small amount observed.

Regarding wettability, ○ indicates that the developer is impatient and remains wet,
× represents a case where residual wetness occurred.

At this time, the developer was 13cc.

Regarding non-foaming property, ○ indicates that no bubbles are generated in the developer;
× indicates that bubbles were generated, and Δ indicates that a small amount of bubbles were generated.

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

-Hand If6zjP'F B orthography (spontaneous)

Claims (3)

[Claims] (1) A positive photoresist developer, which is characterized by adding an alkali-soluble resin and an oxyalkylene group-containing organosiloxane to a positive photoresist developer containing a basic compound as a main component. (2) A positive photoresist according to claim (1), wherein the basic compound is at least one selected from tetramethylammonium hydroxide and trimethyl(2-hydroxyethyl)ammonium hydroxide. developer solution. (3) A positive photoresist developer according to claim (1), wherein the alkali-soluble resin is at least one selected from novolac resin, acetone-pyrogallol resin, polyhydroxystyrene, and derivatives thereof. liquid.