JPH0651507A - Positive resist for exposure with deformed light source - Google Patents

Abstract

PURPOSE:To form a resist pattern with high sensitivity without deteriorating image forming performance such as focus latitude or resolution peculiar to exposure with a deformed light source by using a specified compd. as a photosensitive component. CONSTITUTION:This positive resist contains alkali-soluble novolak resin and 1,2-naphthoquinonediazido-4-sulfonic ester as a photosensitive component. The alkali-soluble novolak resin is obtd. by polycondensing phenols with aldehydes. A compd. represented by the formula may be used as the 1,2- naphthoquinonediazido-4-sulfonic ester as a photosensitive component. In the formula, R is a residue of alcohol or phenol and (n) is an integer of >=1, preferably 1-8. The compd. represented by the formula is obtd. by allowing 1,2- naphthoquinonediazido-4-sulfonyl chloride to react with alcohol and/or phenol, preferably phenol in the presence of a basic catalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist for exposure to a modified light source, which contains a photosensitive component composed of a specific 1,2-naphthoquinonediazide compound.

[0002]

2. Description of the Related Art Conventionally, a positive type resist has been widely used in the manufacture of integrated circuits because a resist pattern of high resolution can be obtained. A resist capable of forming a resist pattern having a high yield is desired. In response to such demands, in recent years, conventional i-line (wavelength 365 nm)
In order to apply the lithography using the above to the formation of a resist pattern of sub-half micron order or less, various attempts have been made in terms of optical construction. As one of them, there is a phase shift method, and it is well known that the resolution is improved thereby. However, in the phase shift method, it is somewhat difficult to manufacture an appropriate phase shift mask, there is no simple method for detecting and correcting defects in the mask, and a conventionally known positive resist can be applied. There are problems such as limited patterns. On the other hand, recently, a "deformed light source exposure method" has been attracting attention as a method for solving the above-mentioned problems in the phase shift method. The modified light source exposure method is used to form an image out of light emitted from a light source, as reported in Proceedings of the 52nd Annual Meeting of the Japan Society of Applied Physics (2nd volume), pages 600-603 (1991). This is a method of improving the imaging performance by cutting off a part of the 0th or ± 1st order light that contributes. This modified light source exposure method will be explained separately (see "Formation of resist pattern" and "Exposure device"), but a typical example is that normal incident light is cut and only oblique light is exposed. By doing so, there is a method of improving the contrast at the resolution limit level. It has been clarified that when the modified light source exposure method is applied to the conventional positive type resist, the resolution, focus tolerance and the like can be improved. However, in this method, since a part of the light emitted from the light source is cut, it is unavoidable that the amount of light reaching the resist film per unit time decreases unless the illuminance of the light source is increased. This is the same as the illuminance of the light source eventually decreased, and the time required for the resist to resolve the pattern becomes longer than that in the normal exposure method, and there is a problem that the sensitivity decreases. It was Such a decrease in sensitivity leads to a decrease in productivity of, for example, an integrated circuit, and its solution has been strongly desired.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to use the modified light source exposure method using i-line without substantially impairing the image forming performance such as the original resolution and focus tolerance of the modified light source exposure method. Another object of the present invention is to provide a positive resist capable of forming a resist pattern with high sensitivity.

[0004]

That is, the present invention provides an alkali-soluble novolak resin and 1,2-
The present invention is directed to a positive resist for exposure to a modified light source, which comprises naphthoquinonediazide-4-sulfonic acid ester. Used in the present invention 1,
2-naphthoquinonediazide-4-sulfonic acid ester is exposed to a large amount of light when exposed to i-rays, as shown in the following reaction formula, because not only carboxylic acid groups but also sulfonic acid groups are generated in the exposed portion of the resist. Without irradiating
The rate of dissolution of the resin component in the alkaline aqueous solution can be sufficiently accelerated, and high sensitivity can be achieved.

[Chemical 1] Therefore, by using 1,2-naphthoquinonediazide-4-sulfonic acid ester as a photosensitive component,
Although it is possible to form a pattern with high sensitivity, there is a trade-off relationship between the sensitivity of a resist and the resolution, that is, the resolution decreases as the sensitivity increases, so that the normal exposure method is sufficient. It was not possible to achieve high sensitivity when trying to obtain high resolution. However, according to the present invention, 1,2-naphthoquinonediazide-4
-When a sulfonate ester is applied as a photosensitive component of a positive resist to a modified light source exposure method, the trade-off phenomenon seen in the ordinary exposure method is not expressed and a fine pattern of sub-half micron order or less is enhanced. It became clear that the sensitivity could be obtained.

The present invention will be described in detail below, which will clarify the purpose, constitution and effect of the present invention. Alkali-soluble novolac resin First, the alkali-soluble novolac resin used in the present invention (hereinafter referred to as "resin (A)") is obtained by polycondensing phenols and aldehydes.

Examples of the phenols include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol,
2,5-xylenol, 2,6-xylenol, 3,4
-Xylenol, 3,5-xylenol, 2,3,5-
Trimethylphenol, 3,4,5-trimethylphenol and the like can be mentioned. These phenols are
Used alone or in combination of two or more. Among the phenols, m-cresol, p-cresol,
2,3-xylenol, 2,5-xylenol, 3,4
-Xylenol, 3,5-xylenol and 2,3
5-trimethylphenol is preferred.

In the resin (A), the following are preferable as the combination of phenols and the co-condensation molar ratio of each phenol. m-cresol / p-cresol: 9
5 to 35/5 to 65 (preferably 80 to 40/20 to 6)
0), m-cresol / 2,3-xylenol: 95-
10/5 to 90 (preferably 80 to 20/20 to 8)
0), m-cresol / 2,3-xylenol / 3,4
-Xylenol: 90-10 / 5-85 / 5-60 (preferably 80-20 / 10-70 / 10-50), m-
Cresol / 2,3-xylenol / 2,3,5-trimethylphenol: 90-10 / 5-85 / 5-60
(Preferably 80-20 / 10-70 / 10-50),
m-cresol / p-cresol / 2,3-xylenol: 90-10 / 5-60 / 5-85 (preferably 70)
~ 20/10 to 50/10 to 70), m-cresol /
2,5-xylenol / 3,5-xylenol: 90-
10/5 to 70/5 to 70 (preferably 80 to 20/1
0-60 / 10-60), m-cresol / 2,5-xylenol / 2,3,5-trimethylphenol: 90
-10/5 to 70/5 to 60 (preferably 80 to 20 /
10-60 / 10-50), m-cresol / 3,4-
Xylenol: 95-50 / 5-50 (preferably 90)
-55 / 10-45), m-cresol / 3,4-xylenol / 2,3,5-trimethylphenol: 90-
20/5 to 50/5 to 60 (preferably 80 to 30/1
0-40 / 10-50), m-cresol / 3,5-xylenol: 95-30 / 5-70 (preferably 90-)
40 / 10-60), m-cresol / p-cresol / 3,5-xylenol: 90-15 / 5-60 / 5
70 (preferably 80 to 30/10 to 45/10 to 6)
0), m-cresol / 3,5-xylenol / 2,
3,5-Trimethylphenol: 90-15 / 5-60
/ 5-60 (preferably 80-20 / 10-50 / 10
~ 50), m-cresol / 2,3,5-trimethylphenol: 95-40 / 5-60 (preferably 90-5)
0/10 to 50), m-cresol / p-cresol /
2,3,5-Trimethylphenol: 90-10 / 5
60 / 5-60 (preferably 80-20 / 10-50 /
10-50).

In addition to the above, a preferable combination of phenols is o-cresol / m-cresol / p.
-Cresol, m-cresol / p-cresol / 3,
4-xylenol, m-cresol / o-cresol /
3,4-xylenol, m-cresol / 2,5-xylenol / 3,4-xylenol, m-cresol / o
-Cresol / 3,5-xylenol, m-cresol / 2,3-xylenol / 3,5-xylenol, m-
Examples thereof include cresol / o-cresol / 2,3,5-trimethylphenol.

The aldehydes to be polycondensed with the phenols include, for example, formaldehyde, acetaldehyde, propyl aldehyde, 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 and the like can be mentioned. Used alone or in combination of two or more. Of the aldehydes, formaldehyde is particularly preferable.

When formaldehyde is used as the aldehyde, examples of the formaldehyde source include formalin, trioxane, paraformaldehyde, and hemiformals such as methyl hemiformal, ethyl hemiformal, propyl hemiformal, butyl hemiformal, and phenyl hemiformal. Can be mentioned. Of these, formalin and butyl hemiformal are particularly preferred.

The amount of the aldehydes used is preferably 0.7 to 3 mol, and more preferably 0.8 to 1.5 mol, based on 1 mol of the phenols.

An acid catalyst is used for the polycondensation of the phenols and the aldehydes. Examples of the acidic catalyst include hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid and the like. The amount of these acidic catalysts used is
Usually 1 × 10 ^{−5 to} 5 × 1 per mol of phenols
It is 0 ^-1 mol.

In the polycondensation of phenols and aldehydes, water is usually used as a reaction medium, but when the phenols used are not dissolved in an aqueous solution of aldehydes and become a heterogeneous system from the beginning of the reaction. It is also possible to use hydrophilic solvents as reaction medium. Examples of the hydrophilic solvent include alcohols such as methanol, ethanol, propanol and butanol, and cyclic ethers such as tetrahydrofuran and dioxane.
The amount of these reaction media used is usually 20 to 1,000 parts by weight per 100 parts by weight of the reaction raw material.

The polycondensation temperature of phenols and aldehydes is appropriately adjusted depending on the reactivity of the reaction raw materials,
It is usually 10 to 200 ° C, preferably 70 to 150 ° C.

As the polycondensation method of phenols and aldehydes, phenols, aldehydes, acidic catalysts and the like are charged all at once, and phenols, aldehydes and optionally added acidic catalysts in the presence of acidic catalysts. A method of gradually adding a catalyst or the like during the reaction can be adopted.

After completion of the polycondensation, in order to remove unreacted raw materials, acidic catalyst, reaction medium and the like existing in the reaction system, the reaction system is generally heated to 130 to 230 ° C. and reduced pressure is applied.
For example, the volatile matter is distilled off under a pressure of about 20 to 50 mmHg to recover the produced resin (A).

The polystyrene reduced weight average molecular weight (hereinafter referred to as "Mw") of the resin (A) used in the present invention is usually 3,000 to 20,000, and particularly 4,000 to 15,000. It is preferable to be within. When the Mw of the resin (A) exceeds 20,000, it may be difficult to uniformly coat the positive resist on the substrate, and the developability and sensitivity tend to be lowered. On the other hand, when Mw is less than 3,000, heat resistance tends to decrease. When a high molecular weight resin (A) is desired, the resin (A) obtained by the polycondensation is dissolved in a good solvent such as ethylene glycol monoethyl ether acetate, dioxane, methanol or ethyl acetate, and then water, n -A poor solvent such as hexane or n-heptane may be mixed, and then the resin solution layer may be separated to recover the fractionated high molecular weight resin (A).

Further, in the present invention, the resin (A) is mixed with a low molecular weight phenol compound (hereinafter,
It is called "compound (B)". ) And can be used in combination, and thereby the alkali solubility of the resin (A) can be improved. The compound (B) is not particularly limited, but preferably has a benzene ring number of about 2 to 6. The amount of the compound (B) used is 100% of the resin (A).
It is usually 70 parts by weight or less, preferably 10 to 50 parts by weight, per part by weight.

Examples of the compound (B) include compounds represented by the following formulas (1) to (8).

[Chemical 2] ,

[Chemical 3] ,

[Chemical 4] ,

[Chemical 5] ,

[Chemical 6] ,

[Chemical 7] ,

[Chemical 8] ,

[Chemical 9] [In the formulas (1) to (8), a, b and c are each an integer of 0 to 3 (provided that each is 0), and x, y and z are 0 to 3 respectively. It is an integer. ]

Photosensitive Component The 1,2-naphthoquinonediazide-4-sulfonic acid ester which is a photosensitive component in the present invention is, for example, a compound represented by the following formula (9) (hereinafter referred to as "compound (C)"). Can be mentioned.

[Chemical 10] [In the formula (9), R is a residue of an alcohol or a phenol, and n is 1 or more, preferably an integer of 1 to 8. ]

The compound (C) can be obtained by reacting 1,2-naphthoquinonediazide-4-sulfonyl chloride with alcohol and / or phenol, preferably phenol, in the presence of a basic catalyst. .

Examples of the compound (C) include (poly) hydroxybenzene 1, such as p-cresol, resorcinol, pyrogallol and phloroglucinol.
2-naphthoquinonediazide-4-sulfonic acid ester;
2,4-dihydroxyphenyl propyl ketone, 2,4
-Dihydroxyphenyl-n-hexyl ketone, 2,4
-Dihydroxybenzophenone, 2,3,4-trihydroxyphenyl-n-hexylketone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxy Benzophenone, 2,2 ', 3,4-tetrahydroxybenzophenone, 3'-methoxy-2,3,4
4'-tetrahydroxybenzophenone, 2,2 ',
4,4'-tetrahydroxybenzophenone, 2,
2 ', 3,4,6-pentahydroxybenzophenone,
(Poly) hydroxyphenylalkylketone or (poly) hydroxyphenyl such as 2,3 ', 4,4', 5'-pentahydroxybenzophenone, 2,3,3 ', 4,4', 5'-hexahydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid ester of aryl ketone; bis (4-hydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane,
2,2-bis (4-hydroxyphenyl) propane,
Bis [(poly) hydroxyphenyl] such as 2,2-bis (2,4-dihydroxyphenyl) propane and 2,2-bis (2,3,4-trihydroxyphenyl) propane
1,2-naphthoquinonediazide-4-sulfonic acid ester of alkane; 4,4'-dihydroxytriphenylmethane, 4,4 ', 4 "-trihydroxytriphenylmethane, 2,2', 5,5'-tetra Methyl-2 ", 4
4'-trihydroxytriphenylmethane, 3,3 ',
5,5'-tetramethyl-2 ", 4,4'-trihydroxytriphenylmethane, 4,4 ', 5,5'-tetramethyl-2,2', 2" -trihydroxytriphenylmethane, 2 , 2 ', 5,5'-tetramethyl-4,
4 ', 4 "-trihydroxytriphenylmethane, 1,
1,1-tris (4-hydroxyphenyl) ethane,
1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl)-
1,2-naphthoquinonediazide of (poly) hydroxytriphenylalkane such as 4- [1- (4-hydroxyphenyl) -1-methylethyl] -1-phenylethane
4-sulfonic acid ester; lauryl 3,5-dihydroxybenzoate, phenyl 3,5-dihydroxybenzoate,
Lauryl 3,4,5-trihydroxybenzoate, 3,
Propyl 4,5-trihydroxybenzoate, 3,4,5
1,2-naphthoquinonediazide-4-sulfonic acid ester of (poly) hydroxybenzoic acid alkyl ester such as phenyl trihydroxybenzoate or (poly) hydroxybenzoic acid aryl ester; bis (2,5-dihydroxybenzoyl) methane, Bis (2,3,4-trihydroxybenzoyl) methane, bis (2,4,6-trihydroxybenzoyl) methane, p-bis (2,5-
Dihydroxybenzoyl) benzene, p-bis (2,2
1,4-bis ((poly) hydroxybenzoyl] alkane such as 3,4-trihydroxybenzoyl) benzene and p-bis (2,4,6-trihydroxybenzoyl) benzene or 1,2-bis ((poly) hydroxybenzoyl] benzene -Naphthoquinonediazide-4-sulfonic acid ester; ethylene glycol-di (3,5-dihydroxybenzoate), polyethylene glycol-di (3,5-
1,2-naphthoquinonediazide-4-of (poly) ethylene glycol-di [(poly) hydroxybenzoate] such as dihydroxybenzoate), polyethylene glycol-di (3,4,5-trihydroxybenzoate)
Sulfonic acid ester; 2,4,4-trimethyl-2 ',
4 ', 7-trihydroxy-2-phenylflavan,
2,4,4'-trimethyl-2 ', 4', 5 ', 6,7
1,2-naphthoquinonediazide-4-sulfonic acid ester of (poly) hydroxyphenylflavan such as pentahydroxy-2-phenylflavan; phenol novolac resin, phenol / o-cresol novolac resin, phenol / m-cresol. Novolac resin, phenol / p-cresol novolac resin, phenol / m-cresol / p-cresol novolac resin, o-cresol novolac resin, m-cresol novolac resin, p-cresol novolac resin, o-cresol / Contains phenolic hydroxyl groups such as m-cresol novolac resin, m-cresol / p-cresol novolac resin, o-cresol / m-cresol / p-cresol novolac resin, poly (hydroxystyrene) resin 1,2-naphthoquinonediazide-4-sulfonic acid esters of fat, and the like. Further, 1,2-naphthoquinonediazide-4-sulfonic acid ester described in JP-A-1-14463 and JP-A-1-156738 of the present applicant can also be used.

The photosensitive component in the positive resist of the present invention does not mean only a single compound represented by the above formula (9) but a mixture of two or more compounds represented by the formula. You can also For example, when alcohol or phenol is a polyvalent compound, the reaction products of these and 1,2-naphthoquinonediazide-4-sulfonyl chloride differ in the number of 1,2-naphthoquinonediazide-4-sulfonic acid ester groups. It may be obtained as a mixture of two or more compounds. Such a mixture is also included in the photosensitive component in the invention.

Among the compounds (C), particularly preferred compounds are 1,2-naphthoquinonediazide-4-sulfonic acid ester of 2,3,4-trihydroxybenzophenone and 2,3,4,4'-tetrahydroxy. 1,2-naphthoquinonediazide-4-sulfonic acid ester of benzophenone, 3'-methoxy-2,3,4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,2 ' , 5,5'-Tetramethyl-2 ", 4,4'-trihydroxytriphenylmethane 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,1,1-tris (4-hydroxyphenyl) ethane 1,2-naphthoquinonediazide-4
-Sulfonic acid ester, 1,1-bis (4-hydroxyphenyl) -1-phenylethane 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,1-bis (4-hydroxyphenyl) -4- [ 1,2-naphthoquinonediazide-4-sulfonic acid ester of 1- (4-hydroxyphenyl) -1-methylethyl] -1-phenylethane, 2,4,4-trimethyl-2 ′, 4 ′, 7-
1,2-naphthoquinonediazide-4-sulfonic acid ester of trihydroxy-2-phenylflavan, or o-cresol novolac resin, m-cresol novolac resin, p-cresol novolac resin, o-
Hydrogen of phenolic hydroxyl group present in cresol / m-cresol novolac resin, m-cresol / p-cresol novolac resin, o-cresol / m-cresol / p-cresol novolac resin, poly (hydroxystyrene) resin, etc. It is a 1,2-naphthoquinonediazide-4-sulfonic acid ester (average esterification rate = 20 to 100%) in which 20 to 100 mol% of atoms are substituted with a 1,2-naphthoquinonediazide-4-sulfonyl group.

The compounding amount of the compound (C) in the positive resist of the present invention is based on 100 parts by weight of the resin (A).
It is usually 3 to 100 parts by weight, preferably 5 to 50 parts by weight. In this case, the total amount of 1,2-naphthoquinonediazide-4-sulfonyl groups in the positive resist is usually adjusted to 5 to 25% by weight, preferably 10 to 20% by weight.

Additives In the positive resist of the present invention, if necessary, a sensitizer,
Various additives such as a surfactant can be blended. The sensitizer improves the sensitivity of a positive resist, and examples thereof include 2H-pyrido- (3,2-b).
-1,4-Oxazin-3 (4H) -ones, 10H-
Pyrido- (3,2-b) -1,4-benzothiazines,
Examples thereof include urazoles, hydantoins, parbituric acids, glycine anhydrides, 1-hydroxybenzotriazoles, alloxans, maleimides and the like. The compounding amount of these sensitizers is usually 50 parts by weight or less, preferably 30 parts by weight or less, relative to 100 parts by weight of the resin (A).

The above-mentioned surfactant has a function of improving the coatability and developability of the positive type resist, and examples thereof include polyoxyethylene lauryl ether, polyoxyethylene oleyl ether and polyoxyethylene octylphenyl. Nonionic surfactants such as ether, polyoxyethylene nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, KP which is an organopolysiloxane polymer
341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), an acrylic acid-based or methacrylic acid-based polymer, Polyflow No. 341. 7
5, No. 95 (trade name, manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.), and F-top EF30 as a fluorochemical surfactant
1, EF303, EF352 (trade name, manufactured by Shin-Akita Kasei), Megafax F171, F172, F173
(Product name, made by Dainippon Ink), Florard FC430,
FC431 (trade name, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101,
SC-102, SC-103, SC-104, SC-1
05, SC-106 (trade name, manufactured by Asahi Glass) and the like. The content of these surfactants is usually 2 parts by weight or less based on 100 parts by weight of the solid content of the positive resist.

Furthermore, the positive resist of the present invention may contain dyes and pigments and an adhesion aid. The former can visualize the latent image of the exposed portion to suppress the effect of halation during exposure, and the latter can improve the adhesion to the substrate. Further, if necessary, a storage stabilizer, a defoaming agent, etc. may be added.

Preparation of Positive Resist Solution When forming a resist pattern using the positive resist of the present invention, a resin (A), a compound (B), a compound (C), and if necessary, are mixed. The various additives described above are dissolved in a solvent so that the solid content concentration is, for example, 20 to 40% by weight, and filtered through a filter having a pore size of about 0.2 μm to prepare a solution. Therefore, the positive resist of the present invention means, in one aspect, a composition comprising a resin (A), a compound (B), a compound (C), and the above-mentioned various additives which are optionally mixed. In yet another aspect, what is meant is a solution of the above composition in a solvent,
Must be understood.

Solvents used for preparing this solution include, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol. Monomethyl ether acetate, propylene glycol monopropyl ether acetate, toluene, xylene, methyl ethyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethoxy Ethyl acetate, ethyl hydroxyacetate, 2-
Methyl hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3
-Methyl ethoxypropionate, ethyl 3-ethoxypropionate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate and the like can be mentioned. These solvents are used alone or in admixture of two or more.

The solvent is N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethylether. , Dihexyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, carbonic acid It can also be used in combination with a high boiling point solvent such as propylene or ethylene glycol monophenyl ether acetate.

The positive resist of the present invention prepared as a resist pattern forming solution is formed on a substrate such as a silicon wafer or a wafer covered with aluminum by a coating method such as spin coating, cast coating, or roll coating. To form a resist film, irradiate i-line through a predetermined mask pattern, and then develop with a developing solution to form a resist pattern.

The positive resist of the present invention is applied to the formation of a resist pattern using a modified light source exposure method. The modified light source exposure method in the present invention is
By controlling the light source, the shape of the filter or diaphragm, the size of the filter or diaphragm, the light transmittance of the filter or diaphragm, etc., in the exposure apparatus, the light incident obliquely with respect to the optical axis (hereinafter referred to as “oblique incident light”). An exposure method using only) as irradiation light for the resist film. Is defined as. Therefore, the exposure methods called “oblique incidence light irradiation method”, “ring-shaped illumination method”, etc. also belong to the category of this modified light source exposure method. By such a modified light source exposure method, light parallel to the optical axis, such as the 0th order light, is cut.

Various methods have been proposed for obtaining obliquely incident light. For example, a method using a filter as shown in (a) or (b) of FIG. The position of cutting the light in the system is not particularly limited, and the light may be cut at any position between the light source and the reticle, including the light source or the reticle. Further, when using a mask that cuts light in order to obtain obliquely incident light, various shapes such as a dot shape and a cross shape in the optical axis portion have been proposed,
It is not particularly limited.

By using the modified light source exposure method, the resolution, focus allowance, etc. of the positive type resist are remarkably improved as compared with the ordinary exposure method. The principle is as follows. It is described in the proceedings of the academic conference (second volume), pages 600 to 603 (1991).
That is, in the normal exposure method, since the light transmitting portions of the filter and the diaphragm are on the optical axis, the light parallel to the optical axis and the obliquely incident light are imaged on the resist film, and the light flux between the adjacent light beams is increased. The angle was small. On the other hand, in the modified light source exposure method, the light that contributes to the image formation mainly consists of obliquely incident light by cutting or weakening all the light parallel to the optical axis. It can be substantially larger.
In general, the larger the angle between adjacent light fluxes on the resist film, the smaller the pitch of the light interference fringes and the higher the resolution, so the modified light source exposure method has a higher resolution than the ordinary exposure method. is there. On the other hand, regarding the focus allowance, in the normal exposure method, when the resist film shifts from the focus position, the optical path difference between the light parallel to the optical axis and the oblique incident light becomes large. Since it is possible to reduce the optical path difference between them, the depth of focus is improved and the focus admissibility is improved.

When forming a pattern using the positive resist of the present invention, the positive resist is applied as a solution on a substrate, prebaked and exposed by a modified light source, and then 70 to 140 ° C. The effect of the present invention can be further improved by performing a heat treatment operation in step 1, and then developing with a developing solution.

As the developing solution for the positive resist of the present invention, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate,
Ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1 , 8-diazabicyclo- [5,4,0] -7-undecene, 1,5-diazabicyclo- [4,3,0] -5-nonane and the like, the concentration of which is usually 1 to 10% by weight, It is preferable to use an alkaline aqueous solution which is dissolved to have a concentration of 2 to 5% by weight. Further, a proper amount of a water-soluble organic solvent, for example, alcohol such as methanol or ethanol, or a surfactant can be added to the developer. In the case of developing with a developing solution composed of such an alkaline aqueous solution, generally, after development, washing with water and drying.

[0038]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. [Synthesis of Resin (A)] Synthesis Example 1 60.6 g (0.56 mol) of m-cresol, 2,3
5-Trimethylphenol 19.1 g (0.14 mol), 37 wt% formaldehyde aqueous solution 49.5 g
(Formaldehyde: 0.61 mol), oxalic acid dihydrate 4.41 g (0.035 mol), water 58.5 g, and dioxane 269 g were charged into an autoclave, and then the autoclave was immersed in an oil bath to prepare a reaction solution. While maintaining the temperature of 140 ° C under stirring, polycondensation was performed for 6 hours. After the reaction, the mixture was cooled to room temperature and the contents were taken out in a beaker. After separating into two layers in a beaker, the lower layer (resin solution layer) was taken out, concentrated, dehydrated and dried to recover the resin (A). This resin is called resin (A1).

Synthesis Example 2 45.4 g (0.42 mol) of m-cresol, 2,3-
Xylenol 25.7 g (0.21 mol), 3,4-xylenol 8.55 g (0.07 mol), 37 wt% formaldehyde aqueous solution 55.7 g (formaldehyde:
0.69 mol), oxalic acid dihydrate 4.41 g (0.0
35 mol), 54.52 g of water, and dioxane 269
g was charged into an autoclave, then the autoclave was immersed in an oil bath, and polycondensation was carried out for 1.5 hours while stirring while maintaining the temperature of the reaction solution at 140 ° C. Then, the temperature of the reaction solution was lowered to 130 ° C., and polycondensation was further performed for 6.5 hours. After the reaction, the resin (A) was recovered in the same manner as in Synthesis Example 1. This resin is referred to as resin (A2).

Synthesis Example 3 45.4 g (0.42 mol) of m-cresol, 2,3-
Xylenol 25.7 g (0.21 mol), 2,3,5
-Trimethylphenol 9.54 g (0.07 mol),
37% by weight aqueous formaldehyde solution 52.3 g (formaldehyde: 0.64 mol), oxalic acid dihydrate 4.4
1 g (0.035 mol), 57.8 g of water, and 272 g of dioxane were charged into an autoclave, and then the autoclave was immersed in an oil bath, and the temperature of the reaction solution was 110 ° C.
Polycondensation was carried out for 1.5 hours with stirring while maintaining the temperature at 10.
Then, the temperature of the reaction solution was raised to 130 ° C., and polycondensation was further performed for 6.5 hours. After the reaction, the resin (A) was recovered in the same manner as in Synthesis Example 1. This resin is
3).

Synthesis Example 4 60.6 g (0.56 mol) of m-cresol, 2,3-
8.55 g (0.07 mol) of xylenol, 8.55 g (0.07 mol) of 3,4-xylenol, 51.1 g of 37% by weight formaldehyde aqueous solution (formaldehyde:
0.63 mol), oxalic acid dihydrate 4.41 g (0.0
35 mol), 55.7 g of water, and 262 g of dioxane.
Was charged into an autoclave and polycondensation was carried out for 8 hours.
Thereafter, the resin (A) was recovered in the same manner as in Synthesis Example 1. This resin is referred to as resin (A4).

Synthesis Example 5 A flask equipped with a stirrer, a condenser and a thermometer was charged with m-
Cresol 60.6 g (0.56 mol), 3,4-xylenol 7.33 g (0.060 mol), 37 wt% formaldehyde aqueous solution 73.0 g (formaldehyde:
0.90 mol), and 1.26 g of oxalic acid dihydrate.
(0.010 mol) was charged, then the flask was immersed in an oil bath, and polycondensation was carried out for 1 hour under stirring while maintaining the temperature of the reaction solution at 100 ° C. Then, 15.1 g (0.14 mol) of m-cresol and 29.3 g (0.24 mol) of 3,4-xylenol were added, and polycondensation was further performed for 2 hours. After the reaction, increase the temperature of the oil bath to 180
Up to ° C, and at the same time, 30-50 mmHg in the flask
The pressure was reduced to volatiles to remove volatiles. Then, the molten resin (A) was cooled to room temperature and recovered. This resin is
5).

Synthesis Example 6 Resin (A5) was dissolved in methyl 3-methoxypropionate so that the solid content was 20% by weight, and 0.9 times the amount of toluene and 0. After adding 5-fold amount of n-hexane and stirring, the mixture was left standing. The lower layer (resin solution layer) separated into two layers by standing was taken out, concentrated, dehydrated and dried to recover the resin (A). This resin is designated as resin (A6).

Synthesis Example 7 m-Cresol 32.4 was placed in the same flask as in Synthesis Example 5.
g (0.30 mol), 37 wt% formaldehyde aqueous solution 77.1 g (formaldehyde: 0.95 mol), and oxalic acid dihydrate 1.26 g (0.010 mol),
Then, the flask was immersed in an oil bath, and polycondensation was carried out for 15 minutes while stirring while maintaining the temperature of the reaction solution at 100 ° C. Then, p-cresol 43.3 g
(0.40 mol), and 32.4 g of m-cresol.
(0.30 mol) was added, and polycondensation was further performed for 80 minutes. After the reaction, the resin (A) was recovered in the same manner as in Synthesis Example 5. This resin is referred to as resin (A7).

Synthesis Example 8 Resin (A7) was dissolved in methyl 3-methoxypropionate to a solid content of 30% by weight, and 0.7 times the amount of toluene and 0.1% by weight of the resin solution was dissolved. After adding 35-fold amount of n-hexane and stirring, the mixture was left standing. Then, the resin (A) was recovered in the same manner as in Synthesis Example 6. This resin is designated as resin (A8).

Examples 1 to 6 and Comparative Examples 1 to 2 Resin (A), compound (B), compound (C) and solvent having the compositions shown in Table 1 (where parts are parts by weight) are mixed. Then, a uniform solution was prepared and then filtered through a membrane filter having a pore size of 0.2 μm to prepare a resist solution. The measuring method of Mw of each resin (A) is as follows. Mw: Toso Corp. GPC column (G2000H _xL 2
Gel, G3000H _xL, 1 G4000H _xL, 1), gel permeation chromatograph using monodisperse polystyrene as standard under analysis conditions of liquid volume 1.0 ml / min, elution solvent tetrahydrofuran, column temperature 40 ° C. It was measured by the method.

The compounds (B), compounds (C) and solvents in Table 1 are as follows. Compound (B) (B1): 1,1,3-tris (2,5-dimethyl-4)
-Hydroxyphenyl) propane (B2): 1,1-bis (4-hydroxyphenyl)-
γ-phenylethane (B3): 1,1,1-tris (4-hydroxyphenyl) ethane (B4): 1,1-bis (2,5-dimethyl-4-hydroxyphenyl) -1- (2-hydroxy Phenyl) methane

Compound (C) (C1): 1,1,1-tris (4-hydroxyphenyl) ethane (1 mol) and 1,2-naphthoquinonediazide-4
-Condensation product with sulfonyl chloride (2.5 mol) (C2): 1,1-bis (4-hydroxyphenyl)-
Condensate of 1 mol of 4- [1- (4-hydroxyphenyl) -1-methylethyl] -1-phenylethane and 2.3 mol of 1,2-naphthoquinonediazide-4-sulfonyl chloride (C3): 1, 1-bis (4-hydroxyphenyl)-
Condensate of 1 mol of 4- [1- (4-hydroxyphenyl) -1-methylethyl] -1-phenylethane and 2.7 mol of 1,2-naphthoquinonediazide-4-sulfonyl chloride (C4): 2, 4,4-trimethyl-2 ', 4', 7-
1 mol of trihydroxy-2-phenylflavan and 1,2
-Naphthoquinonediazide-4-sulfonyl chloride 2.
Condensate with 5 moles (C5): m-clasol novolac resin (Mw =
2,300) and 1,2-naphthoquinonediazide-4-sulfonyl chloride condensate (average esterification rate = 25
%) (C6): 1,1-bis (4-hydroxyphenyl)-
Condensation product of 1 mol of 4- [1- (4-hydroxyphenyl) -1-methylethyl] -1-phenylethane and 2.7 mol of 1,2-naphthoquinonediazide-5-sulfonyl chloride

Solvent (α): Ethylene glycol monoethyl ether acetate (β): Methyl 3-methoxypropionate (γ): Ethyl 2-hydroxypropionate

Each of the obtained resist solutions was applied onto a silicon wafer having a silicon oxide film by using a spinner, and then 90 ° C (however, 100 ° C only in Example 5).
Prebaked on a hot plate for 2 minutes to a thickness of 1.2
A μm resist film was formed. Next, these resist films were exposed by an i-ray having a wavelength of 365 nm through a reticle using the following exposure device, and then post-exposure baking was performed on a hot plate at 110 ° C. for 1 minute. Then, development, washing and drying were performed to obtain a resist pattern.

Exposure device As an exposure device, NSR-1505i6A manufactured by Nikon Corporation
A reduction projection exposure machine (lens numerical aperture: 0.45) was used.
At this time, in the case of the normal exposure method, the exposure was performed as it was, but in the case of the modified light source exposure method, the central part of the aperture of the optical path was
It was shielded with a horizontally long mask (hatched portion) of b / a = 1/5 having the shape shown in FIG. FIG. 3 shows the traveling states of light distributed in the length direction of the mask in the ordinary exposure method and the modified light source exposure method. In FIG. 3, 1 is an aperture part, 2 is a mask, 3 is a reticle, 4 is a projection lens, 5 is a wafer, a (dashed line) is light transmitted through the center of the aperture, and b (solid line) is transmitted through the mask edge part. Light and c (solid line) are light that passes through the aperture edge portion. In the normal exposure method, the light b which goes straight through the center of the aperture also contributes to image formation, but in the modified light source exposure method, the light b which goes straight through this center of the aperture is cut, and the light b Only C and the like are incident.

Based on the resist patterns, various characteristics of each resist were evaluated by the following methods. The evaluation results are shown in Table 2. Sensitivity Using the above-mentioned exposure device, exposure was performed while changing the exposure time. Then, a 2.4% by weight aqueous solution of tetramethylammonium hydroxide was used for development at 25 ° C. for 60 seconds, followed by washing with water and drying to form a resist pattern on the substrate. In this case, the exposure amount per unit area (hereinafter referred to as “optimum exposure amount”) for forming a 0.5 μm line-and-space pattern (hereinafter referred to as “ILIS pattern”) in a width of 1: 1. I asked.
The smaller the optimum exposure amount is, the better the sensitivity is. Resolution The minimum dimension of the resist pattern resolved when exposed with the optimum exposure amount was defined as the resolution. A focus permissible scanning electron microscope was used to measure the range of focus deviation (hereinafter referred to as “focus range”) when a good pattern was formed for an ILIS pattern of 0.5 μm. The larger the focus range, the better the focus tolerance. Remaining film ratio For the resist pattern exposed with the optimum exposure amount, the pattern thickness T ₁ after development and the resist film thickness T before development
₂ ratio of T ₁ / T ₂ (unit%), was residual film rate. The scum and undeveloped degree of the resist pattern after development developer was evaluated developability. The pattern shape scanning electron microscope was used to measure the lower side width W ₁ and the upper side width W _{2 of the} rectangular cross section of the ILIS pattern of 0.5 μm which was resolved when the exposure was performed at the optimum exposure amount. ≤W
_{When 2} / W ₁ ≦ 1, the pattern shape was considered to be good. However, if the bottom side of the pattern has a hem or the pattern shape is inversely tapered, W ₂ / W ₁
Regardless of, the pattern shape is not good. The substrate on which the heat-resistant resist pattern was formed was placed in a clean oven to raise the temperature, and the heat resistance was evaluated by the temperature at which the shape of the pattern began to collapse.

[0053]

[Table 1]

[0054]

[Table 2]

As is clear from Table 2, the positive resist of the present invention can be applied to the modified light source exposure method to form a pattern having high sensitivity and high resolution and excellent focus tolerance. In addition, the residual film rate, developability, pattern shape and heat resistance are good. On the other hand, 1,2-, which is a kind of naphthoquinone diazide sulfonic acid ester, like the photosensitive component of the present invention.
In the case of using naphthoquinonediazide-5-sulfonic acid ester (Comparative Example 1), when the modified light source exposure method is used for exposure, the sensitivity is particularly lowered, and the above-mentioned problems of the modified light source exposure method cannot be solved. However, the resolution and focus tolerance are rather reduced. On the other hand, in the ordinary exposure method (Comparative Example 2), even when 1,2-naphthoquinonediazide-4-sulfonic acid ester is used as a photosensitive component, when a pattern of sub-half micron order or less is formed, resolution and focus allowance are obtained. The property is remarkably deteriorated and it is impossible to form a fine pattern. Therefore, the action and effect of the present invention obtained by applying a positive resist containing an alkali-soluble novolac resin and 1,2-naphthoquinonediazide-4-sulfonic acid ester as a photosensitive component, particularly to a modified light source exposure method is completely unexpected. It is a thing.

[0056]

The positive resist for exposure to modified light source according to the present invention has remarkably excellent sensitivity and substantially impairs the image forming performance such as resolution and focus tolerance, which are the original advantages of the modified light source exposure method. Therefore, a fine resist pattern having a good shape can be formed with high efficiency. Therefore, it is extremely useful as a resist or the like for manufacturing an integrated circuit, which is expected to have higher integration in the future.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a filter for obtaining obliquely incident light.

FIG. 2 is a plan view of a mask for obtaining obliquely incident light.

FIG. 3 is a diagram showing a traveling state of light in a modified light source exposure method and a normal exposure method.

[Explanation of symbols]

 1 Aperture part 2 Mask 3 Reticle 4 Projection lens 5 Wafer I Light that passes through the center of the aperture B Light that passes through the mask edge part Light that passes through the aperture edge part

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 10, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

Examples of the compound (B) include compounds represented by the following formulas (1) to (8). [In the formulas (1) to (8), a, b and c are each an integer of 0 to 3 (provided that each is 0), and x, y and z are 0 to 3 respectively. It is an integer. ]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

The compound (C) can be obtained by reacting 1,2-naphthoquinonediazide-4-sulfonyl chloride with an alcohol and / or a phenol, preferably a phenol, in the presence of a basic catalyst.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

Examples of the compound (C) include (poly) hydroxybenzene 1, such as p-cresol, resorcinol, pyrogallol and phloroglucinol.
2-naphthoquinonediazide-4-sulfonic acid ester;
2,4-dihydroxyphenyl propyl ketone, 2,4
-Dihydroxyphenyl-n-hexyl ketone, 2,4
-Dihydroxybenzophenone, 2,3,4-trihydroxyphenyl-n-hexylketone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxy Benzophenone, 2,2 ', 3,4-tetrahydroxybenzophenone, 3'-methoxy-2,3,4
4'-tetrahydroxybenzophenone, 2,2 ',
4,4'-tetrahydroxybenzophenone, 2,
2 ', 3,4,6-pentahydroxybenzophenone,
(Poly) hydroxyphenylalkylketone or (poly) hydroxyphenyl such as 2,3 ', 4,4', 5'-pentahydroxybenzophenone, 2,3,3 ', 4,4', 5'-hexahydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid ester of aryl ketone; bis (4-hydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane,
2,2-bis (4-hydroxyphenyl) propane,
Bis [(poly) hydroxyphenyl] such as 2,2-bis (2,4-dihydroxyphenyl) propane and 2,2-bis (2,3,4-trihydroxyphenyl) propane
1,2-naphthoquinonediazide-4-sulfonic acid ester of alkane; 4,4'-dihydroxytriphenylmethane, 4,4 ', 4 "-trihydroxytriphenylmethane, 2,2', 5,5'-tetra Methyl-2 ", 4
4'-trihydroxytriphenylmethane, 3,3 ',
5,5'-tetramethyl-2 ", 4,4'-trihydroxytriphenylmethane, 4,4 ', 5,5'-tetramethyl-2,2', 2" -trihydroxytriphenylmethane, 2 , 2 ', 5,5'-tetramethyl-4,
4 ', 4 "-trihydroxytriphenylmethane, 1,
1,1-tris (4-hydroxyphenyl) ethane,
1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl)-
1,5-naphthoquinonediazide-4-sulfonic acid ester of (poly) hydroxytriphenylalkane such as 1- [4- {1- (4-hydroxyphenyl) -1-methylethyl} phenyl] ethane; Lauryl dihydroxybenzoate, phenyl 3,5-dihydroxybenzoate, lauryl 3,4,5-trihydroxybenzoate,
Propyl 3,4,5-trihydroxybenzoate, 3,
(Poly) such as phenyl 4,5-trihydroxybenzoate
1,2-naphthoquinonediazide-4-sulfonic acid ester of hydroxybenzoic acid alkyl ester or (poly) hydroxybenzoic acid aryl ester; bis (2,5
-Dihydroxybenzoyl) methane, bis (2,3,4)
-Trihydroxybenzoyl) methane, bis (2,4,4
6-trihydroxybenzoyl) methane, p-bis (2,5-dihydroxybenzoyl) benzene, p-bis (2,3,4-trihydroxybenzoyl) benzene, p-bis (2,4,6-trihydroxybenzoyl) ) 1,2-naphthoquinonediazide-4-sulfonic acid ester of bis [(poly) hydroxybenzoyl] alkane such as benzene or bis [(poly) hydroxybenzoyl] benzene; ethylene glycol-di (3,5-
1 of (poly) ethylene glycol-di [(poly) hydroxybenzoate] such as dihydroxybenzoate), polyethylene glycol-di (3,5-dihydroxybenzoate), polyethylene glycol-di (3,4,5-trihydroxybenzoate) , 2-naphthoquinonediazide-4-sulfonic acid ester; 2,4,4-trimethyl-2 ', 4', 7-trihydroxy-2-phenylflavan, 2,4,4'-trimethyl-2 ', 4' ，
1,2-of (poly) hydroxyphenyl flavans such as 5 ', 6,7-pentahydroxy-2-phenyl flavan
Naphthoquinonediazide-4-sulfonic acid ester; phenol novolac resin, phenol / o-cresol novolac resin, phenol / m-cresol novolac resin, phenol / p-cresol novolac resin, phenol / m-cresol / p-cresol・
Novolac resin, o-cresol novolac resin, m
-Cresol novolac resin, p-cresol novolac resin, o-cresol / m-cresol novolac resin, m-cresol / p-cresol novolac resin, o-cresol / m-cresol / p-cresol novolac resin, Examples thereof include 1,2-naphthoquinonediazide-4-sulfonic acid ester of a phenolic hydroxyl group-containing resin such as poly (hydroxystyrene) resin. Further, 1,2-naphthoquinonediazide-4-sulfonic acid ester described in JP-A-1-14463 and JP-A-1-156738 of the present applicant can also be used.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

Among the compounds (C), particularly preferred compounds are 1,2-naphthoquinonediazide-4-sulfonic acid ester of 2,3,4-trihydroxybenzophenone and 2,3,4,4'-tetrahydroxy. 1,2-naphthoquinonediazide-4-sulfonic acid ester of benzophenone, 3'-methoxy-2,3,4,4'-tetrahydroxybenzophenone 1,2-naphthoquinonediazide-4-sulfonic acid ester, 2,2 ' , 5,5'-Tetramethyl-2 ", 4,4'-trihydroxytriphenylmethane 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,1,1-tris (4-hydroxyphenyl) ethane 1,2-naphthoquinonediazide-4
-Sulfonic acid ester, 1,1-bis (4-hydroxyphenyl) -1-phenylethane 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,1-bis (4-hydroxyphenyl) -1- [ 4- {1- (4-
Hydroxyphenyl) -1-methylethyl} phenyl]
1,2-naphthoquinonediazide-4-sulfonic acid ester of ethane, 2,4,4-trimethyl-2 ', 4', 7
-1,2-naphthoquinonediazide-4-sulfonic acid ester of trihydroxy-2-phenylflavan, or o-cresol novolac resin, m-cresol
Novolac resin, p-cresol novolac resin, o
-Cresol / m-cresol novolak resin, m-
Cresol / p-cresol novolac resin, o-cresol / m-cresol / p-cresol novolac resin, poly (hydroxystyrene) resin, etc. A 1,2-naphthoquinonediazide-4-sulfonic acid ester substituted with a naphthoquinonediazide-4-sulfonyl group (average esterification rate = 20 to 100%).

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0037

[Correction method] Change

[Correction content]

As the developing solution for the positive resist of the present invention, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate,
Ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1 , 8-diazabicyclo- [5,4,0] -7-undecene, 1,5-diazabicyclo- [4,3,0] -5-nonene, etc., in a concentration of usually 1 to 10% by weight, It is preferable to use an alkaline aqueous solution which is dissolved to have a concentration of 2 to 5% by weight. Further, a proper amount of a water-soluble organic solvent, for example, alcohol such as methanol or ethanol, or a surfactant can be added to the developer. In the case of developing with a developing solution composed of such an alkaline aqueous solution, generally, after development, washing with water and drying.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction content]

Examples 1 to 6 and Comparative Examples 1 to 2 Resin (A), compound (B), compound (C) and solvent having the compositions shown in Table 1 (where parts are parts by weight) are mixed. Then, a uniform solution was prepared and then filtered through a membrane filter having a pore size of 0.2 μm to prepare a resist solution. The measuring method of Mw of each resin (A) is as follows. Mw: Tosoh Corp. GPC column (G2000H _xL
Two, G3000H _xL 1 this, G4000H _xL 1 pcs.)
Was measured by a gel permeation chromatographic method using monodisperse polystyrene as a standard under the analysis conditions of a flow rate of 1.0 ml / min, an elution solvent of tetrahydrofuran, and a column temperature of 40 ° C.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction content]

Compound (C) (C1): 1,1,1-tris (4-hydroxyphenyl) ethane (1 mol) and 1,2-naphthoquinonediazide-4
-Condensation product with sulfonyl chloride (2.5 mol) (C2): 1,1-bis (4-hydroxyphenyl)-
Condensate of 1- [4- {1- (4-hydroxyphenyl) -1-methylethyl} phenyl] ethane with 2.3 mol of 1,2-naphthoquinonediazide-4-sulfonyl chloride (C3): 1,1 -Bis (4-hydroxyphenyl)-
Condensate of 1- [4- {1- (4-hydroxyphenyl) -1-methylethyl} phenyl] ethane and 2.7 mol of 1,2-naphthoquinonediazide-4-sulfonyl chloride (C4): 2,4 , 4-trimethyl-2 ', 4', 7-
1 mol of trihydroxy-2-phenylflavan and 1,2
-Naphthoquinonediazide-4-sulfonyl chloride 2.
Condensate with 5 moles (C5): m-clasol novolac resin (Mw =
2,300) and 1,2-naphthoquinonediazide-4-sulfonyl chloride condensate (average esterification rate = 25
%) (C6): 1,1-bis (4-hydroxyphenyl)-
Condensation product of 1- [4- {1- (4-hydroxyphenyl) -1-methylethyl} phenyl] ethane and 2.7 mol of 1,2-naphthoquinonediazide-5-sulfonyl chloride

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction content]

Based on the resist patterns, various characteristics of each resist were evaluated by the following methods. The evaluation results are shown in Table 2. Sensitivity Using the above-mentioned exposure device, exposure was performed while changing the exposure time. Then, a 2.4% by weight aqueous solution of tetramethylammonium hydroxide was used for development at 25 ° C. for 60 seconds, followed by washing with water and drying to form a resist pattern on the substrate. In this case, an exposure amount per unit area (hereinafter, referred to as "optimal exposure amount") for forming a 0.5 μm line-and-space pattern (hereinafter, referred to as "1L1S pattern") in a width of 1: 1. I asked.
The smaller the optimum exposure amount is, the better the sensitivity is. Resolution The minimum dimension of the resist pattern resolved when exposed with the optimum exposure amount was defined as the resolution. A focus tolerance scanning electron microscope was used to measure a focus swing range (hereinafter, referred to as “focus range”) when a good pattern was formed for a 0.5 μm 1L1S pattern. The larger the focus range, the better the focus tolerance. Residual film rate Regarding the resist pattern exposed with the optimum exposure amount, the pattern thickness T ₁ after development and the resist film thickness T before development
₂ ratio of _T 1 / _{T 2} (unit%), was residual film rate. The scum and undeveloped degree of the resist pattern after development developer was evaluated developability. The pattern shape scanning electron microscope was used to measure the lower side width W ₁ and the upper side width W _{2 of the} rectangular cross section of the ₁ L1S pattern of 0.5 μm which was resolved at the time of exposure with the optimum exposure amount, and was measured to be 0.85. ≤W
The case where ₂ / W ₁ ≦ 1 was determined to have a good pattern shape. However, if the bottom of the pattern has a hem or the pattern has an inverse taper shape, W ₂ / W
Regardless of ₁ , the pattern shape is not good. The substrate on which the heat-resistant resist pattern was formed was placed in a clean oven to raise the temperature, and the heat resistance was evaluated by the temperature at which the shape of the pattern began to collapse.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takao Miura 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. A positive resist for exposure to a modified light source, which comprises an alkali-soluble novolac resin and 1,2-naphthoquinonediazide-4-sulfonic acid ester as a photosensitive component.