JPH03200253A - Positive type resist composition - Google Patents

Abstract

PURPOSE:To improve sensitivity,resolution, heat resistance, shelf stability, the rate of a residual film, etc., by incorporating alkali-soluble phenol resin, a quinonediazidosulfonic ester type photosensitive agent and a specified compd. CONSTITUTION:This positive type resist compsn. contains alkali-soluble phenol resin, a quinonediazidosulfonic ester type photosensitive agent and a compd. represented by formula I, wherein each of R<1>-R<4> is H, halogen, 1-4C alkyl, alkenyl or hydroxyl, each of R<5> and R<6> is H, halogen or 1-4C alkyl and each of R<7>-R<10> is H or 1-4C alkyl. Sensitivity, resolution, heat resistance, shelf stability, the rate of a residual film, etc., are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a positive resist composition, and more particularly, to a positive resist composition for microfabrication required for manufacturing semiconductor devices, VA bubble memory devices, integrated circuits, etc. The present invention relates to a mold resist composition.

(Conventional technology) When manufacturing semiconductors, a photoresist film is created by applying cyst to the surface of a silicon wafer, and a latent image is formed by irradiating the film with light.
Semiconductor elements are formed by lithography technology in which the image is then developed to form a negative or positive image.

Conventionally, as a resist composition for forming a semiconductor element, a negative resist composed of cyclized polyisoprene and a bisazide compound is known.

However, since this negative resist is developed with an organic solvent, it has a drawback that it cannot be used in the manufacture of highly integrated semiconductors because it swells significantly and has a limited resolution. on the other hand,
In contrast to this negative resist composition, a positive resist composition has excellent resolution and is therefore considered to be able to sufficiently cope with high integration of semiconductors.

Currently, positive resist compositions commonly used in this field are composed of a novolac resin and a quinonediazide compound.

However, conventional positive resist compositions lack sensitivity,
Satisfactory results have not always been obtained with respect to various properties such as resolution, residual film rate, heat resistance, and storage stability, and improvements in performance are strongly desired. In particular, sensitivity is important for improving the productivity of semiconductors, and it is highly desirable to increase the sensitivity of positive resist compositions.For this purpose, the base material components of positive resist compositions In addition to certain novolac resins and quinonediazide compounds, various compounds have been added.

Examples of compounds, ie, sensitizers, added to increase sensitivity include nitrogen heterocyclic compounds such as halogenated benzotriazole derivatives (Japanese Patent Laid-Open No. 58-376
41) and cyclic acid anhydrides (Japanese Patent Publication No. 56-30850).

However, the addition of these sensitizers eliminates the difference in solubility between the exposed and unexposed areas, resulting in a decrease in the residual film rate and deterioration of resolution. Problems such as a decrease in heat resistance arise.

(Objects to be Solved by the Invention) The objects of the present invention are to solve the above-mentioned drawbacks of the prior art, improve sensitivity,
The object of the present invention is to provide a highly sensitive positive resist composition that has excellent properties such as resolution, residual film rate, heat resistance, and storage stability, and is particularly suitable for microfabrication of 1 μm or less.

(Means for Solving the Problems) This object of the present invention is to provide an alkali-soluble phenolic resin,
This is achieved by a positive resist composition containing a quinonediazide sulfonic acid ester photosensitizer and a compound represented by general formula (1).

R1 to R': H, halogen, C, -C, alkyl group,
Alkenyl group or hydroxyl group R'R', H, halogen or 01-C4 alkyl group R? ~R'', H or C1-C4 alkyl Basic examples of the alkali-soluble phenolic resin used in the invention include condensation reaction products of phenols and aldehydes, condensation reaction products of phenols and ketones, vinyl Examples include phenolic polymers, isopropenylphenol polymers, and hydrogenation reaction products of these phenolic resins.

Here, specific examples of phenols used include phenol, cresol, xylenol, ethylphenol,
Examples include monohydric phenols such as propylphenol, butylphenol, and phenylphenol, and polyhydric phenols such as resorcinol, pyrocatechol, hydroquinone, and bisphenol A1 pyrogallol.

Here, specific examples of the aldehydes used include formaldehyde, acetaldehyde, benzaldehyde, and terephthalaldehyde.

Here, specific examples of ketones used include acetone,
Examples include methyl ethyl ketone, diethyl ketone, and diphenyl ketone.

These condensation reactions can be carried out according to conventional methods such as bulk polymerization and solution polymerization.

Moreover, the vinylphenol-based polymer is selected from a homopolymer of vinylphenol and a copolymer of vinylphenol and a copolymerizable component. Specific examples of copolymerizable components include acrylic acid derivatives, methacrylic acid derivatives,
Examples include styrene derivatives, maleic anhydride, maleic acid imide derivatives, vinyl acetate, and acrylonitrile.

The isopropenylphenol polymer is selected from a homopolymer of isopropenylphenol and a copolymer of isopropenylphenol and a copolymerizable component. Specific examples of copolymerizable components include acrylic acid derivatives, methacrylic acid derivatives, styrene derivatives, maleic anhydride, maleic acid imide derivatives, vinyl acetate, acrylonitrile, and the like.

The hydrogenation reaction of these phenolic resins can be carried out by any known method, in which the phenolic resin is dissolved in an organic solvent and hydrogen is released in the presence of a homogeneous or heterogeneous hydrogenation catalyst. This can be achieved by introducing

It is also possible to use these alkali-soluble phenol resins whose molecular weight distribution has been controlled by refractionation or the like. Further, these phenol resins can be used alone, but two or more types may be used in combination.

If necessary, the positive resist composition of the present invention may contain, for example, a copolymer of styrene and acrylic acid, methacrylic acid, or maleic anhydride, in order to improve developability, storage stability, heat resistance, etc. Copolymers of alkenes and maleic anhydride, vinyl alcohol polymers, vinyl pyrrolidone polymers, rosin shellac, etc. can be added.

The amount added is 0 to 50 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the alkali-soluble phenol resin.

The photosensitizer used in the present invention is not particularly limited as long as it is a quinonediazide sulfonic acid ester. As specific examples, the ester moiety is 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-benzoquinonediazide-4-sulfonic acid ester,
-naphthoquinonediazide-5-sulfonic acid ester, 2
．． Examples include compounds such as 1-naphthoquinonediazide-4-sulfonic acid ester, 2.1-naphthoquinonediazide-5-sulfonic acid ester, and other sulfonic acid esters of quinonediazide derivatives.

The photosensitizer in the present invention can be synthesized by an esterification reaction of a quinonediazide sulfonic acid compound, and is based on the photosensitive polymer J (1) written by Gentabu Nagamatsu and Hideo Inui.
980) can be synthesized according to the conventional method described in Kodansha (Tokyo), etc.

The photosensitizers in the present invention can be used alone, or two or more types can be used in combination. The amount of the photosensitizer to be blended is 1 to 100 parts by weight, preferably 3 to 40 parts by weight, based on 100 parts by weight of the resin.

If the amount is less than 1 part by weight, it will be impossible to form a pattern;
If the amount exceeds 0.00 parts by weight, afterimages tend to remain.

The aggravating agent used in the present invention is not particularly limited as long as it is a compound represented by -a formula (1).

Specific examples of the compound represented by general formula (1) include the following.

(4) (1) (6) (2) (7) (8) (9) (10) (11) (16) (17) (18) (19) (12) (13) (15) (20 ) (22) (24) (26) (27) (32) (33) (34) (35) (28) (29) (30) (31) (36) The sensitizer in the present invention can also be used alone. However, two or more types may be mixed and used. The blending amount of the sensitizer is 100 parts by weight or less, preferably 2 to 50 parts by weight, based on 100 parts by weight of the resin.

If the amount of the additive exceeds 100 parts by weight, the residual film rate will drop significantly and pattern formation will become difficult.

The positive resist composition of the present invention is used after being dissolved in a solvent, and examples of the solvent include acetone, methyl ethyl ketone,
Ketones such as cyclohexanone and cyclopentanone,
Alcohols such as n-propyl alcohol, 1so-propyl alcohol, n-butyl alcohol, and cyclohexanol, ethers such as ethylene gelcol dimethyl ether, ethylene glycol diethyl ether, and dioxane, ethylene glycol monomethyl ether,
Alcohol ether chains such as ethylene glycol monoethyl ether, esters such as propyl formate, butyl formate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl lactate, ethyl lactate, cellosolve acetate, Cellosolve esters such as methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, butyl cellosolve acetate, propylene glycols such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether , diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene gelcol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, halogenated hydrocarbons such as trichloroethylene, aromatic hydrocarbons such as toluene and xylene, dimethylacetamide , dimethylformamide, N-methylacetamide, and other polar solvents. These may be used alone or in combination of two or more.

The positive resist composition of the present invention contains compatible additives such as a surfactant, a storage stabilizer, a sensitizer, an IJ anyion inhibitor, a plasticizer, and an antihalation agent, as necessary. can be done.

As the developer for the positive resist composition of the present invention, an alkaline aqueous solution is used. Specifically, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium silicate, ammonia, ethylamine, propylamine, etc. Primary amines, tertiary amines such as diethylamine and dipropylamine, tertiary amines such as trimethylamine and triethylamine, alcohol amines such as diethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide , trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, and other quaternary ammonium salts.

Furthermore, if necessary, add methanol or
Appropriate amounts of water-soluble organic solvents such as ethanol, propatool, and ethylene glycol, surfactants, storage stabilizers, resin dissolution inhibitors, and the like can be added.

(Example) The present invention will be described in more detail with reference to Examples below.

Soil comparison ■ Novolac resin 100 obtained by mixing m-cresol and p-cresol at a molar ratio of 4=6, adding formalin to this, and condensing it using an oxalic acid catalyst in a conventional manner.
By weight, 75% of 2,3,4.4'-tetrahydroxybenzophenone is 1,2-naphthoquinonediazide-5-
Quinonediazide compound 28, which is an ester of sulfonic acid
Parts by weight were dissolved in 350 parts by weight of ethyl cellosolve acetate and filtered through a 0.1 μm Teflon filter to prepare a resist solution.

After applying the above resist solution onto a silicon wafer using a coater, it was betatized at 100°C for 90 seconds to a thickness of 1.1
A resist film of 7 μm was formed. This wafer was transferred to a G-line stepper N5R-xsosc6t <manufactured by Nikon Corporation, N
A=0.54) and a test reticle. Next, it was heated with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23°C for 1 minute.

A positive pattern was obtained by development using the paddle method.

When the sensitivity was evaluated, it was 120 s+J/cJ, and when the film thickness of the pattern was measured with a film thickness meter Alpha Step 200 (manufactured by Tenko Corporation), it was 1.12 μm.

1 for 100 parts by weight of resin in the resist solution of Comparative Example 1
A resist solution was prepared by adding and dissolving a sensitizer of formula (31) at a ratio of 0 parts by weight, and filtering with a 0.1 μm Teflon filter.

This resist solution was processed in the same manner as in Comparative Example 1 to obtain a positive pattern.

When the patterned wafer was taken out and the sensitivity was evaluated, it was 80 mJ/c+fl, and when observed with an electronic W4 microscope, lines and spaces of 0.45 μm were resolved. The film thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 1.13 μm. It was found that the sensitivity was improved compared to the resist of Comparative Example 1.

Furthermore, the wafer with this pattern formed thereon was etched using a dry etching device DEM-45IT (manufactured by Nichiden Anelva).
When etching was performed using a power of 300 W, pressure of 0.03 Torr, gas CF, /H=3/l, and frequency of 13.56 MHz, it was observed that only the areas where there was no pattern were etched.

After applying the resist solution of Example 1 onto a silicon wafer using a coater, it was baked at 90°C for 90 seconds to form a layer with a thickness of 1 m.
．． A resist film of 17 μm was formed.

This wafer is transferred to a G-line stepper NSR-1505G6B.
Exposure was performed using a test reticle. Next, this wafer was subjected to FEB (POSTEXP) at 110°C for 60 seconds.
OSURE BAKING), then heat at 23°C with 2.38% tetramethylammonium hydroxide aqueous solution.
A positive pattern was obtained by developing for 1 minute using the paddle method.

When the patterned wafer was taken out and the sensitivity was evaluated, it was 70 mJ/cj, and when observed with an electron microscope, lines and spaces of 0.40 μm were resolved. The film thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 1.14 μm.

・l~7゛ゝm-cresol, p-cresol, and 3.5-xylenol were mixed at a molar ratio of 50=20:30, formalin was added to this, and the mixture was mixed using an oxalic acid catalyst in a conventional manner. 100 parts by weight of novolac resin obtained by condensation, 2,3
, 95% of 4,4'-tetrahydroxybenzophenone
28 parts by weight of a quinonediazide compound, which is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, and 5 parts by weight of the sensitizer shown in Table 1 were dissolved in 360 parts by weight of ethyl lactate, and a 0.1 um Teflon filter was prepared. A resist solution was prepared by filtration.

After applying the above resist solution onto a silicon wafer with a coater, it was baked at 90°C for 90 seconds to a thickness of 1.17 mm.
A resist film of μm thickness was formed. This wafer was exposed using a g-line stepper NSR-1505G6B and a test reticle. Next, this wafer was subjected to PEB at 110°C for 60 seconds, and then developed with a 2.38% aqueous tetramethylammonium hydroxide solution at 23°C for 1 minute using the paddle method to obtain a positive pattern.

Table 1 shows the results of evaluation after taking out the patterned wafer.

Table 1 〃425 〃514 〃 6 17 〃 7 24 90 1.11 125 1.14 125 1.14 110 1.11 0.40 0.40 0.45 0.40 m-cresol and p-cresol in moles Novolac resin 100 obtained by mixing at a ratio of 8:2, adding formalin to this, and condensing it using an oxalic acid catalyst in a conventional manner.
Part by weight was dissolved in 400 parts by weight of ethyl cellosolve acetate, and this was dropped into 30,001 parts by weight of toluene to precipitate the resin. After filtering the precipitated resin, heat at 60°C.
It was vacuum dried for 30 hours. 100 parts by weight of vacuum-dried resin.

2.3.4.28 parts by weight of a quinonediazide compound in which 95% of 4'-tetrahydroxybenzophenone is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, and 10 parts by weight of an exacerbant represented by formula (lO) were added to lactic acid. ethyl 38
A resist solution was prepared by dissolving 0 parts by weight and filtering through a 0.1 μm Teflon filter.

After applying the above resist solution onto a silicon wafer with a coater, it was baked at 90°C for 90 seconds to a thickness of 1.17 mm.
A resist film of μm thickness was formed. This wafer was exposed using a g-line stepper NSR-1505G6E and a test reticle. Next, this wafer was heated at 110°C for 6
After performing PEB for 0 seconds, it was developed with a 2.38% tetramethylammonium hydroxide aqueous solution at 23°C for 1 minute using the paddle method to obtain a positive pattern.

When the patterned wafer was taken out and the sensitivity was evaluated, it was found to be 90 sJ/c-, and when observed with an electron microscope, lines and spaces of 0.45 μm were resolved. The film thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 1.12 μ-.

Novolak resin 100 obtained by mixing m-cresol and p-cresol at a molar ratio of 7=3, adding formalin to this, and condensing it using an oxalic acid catalyst in a conventional manner.
Parts by weight, Trisphenol PA (manufactured by Mitsui Petrochemicals) 9
35 parts by weight of a quinonediazide compound of which 0% is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, (
13) 7 parts by weight of the aggravating agent shown in formula 13) was dissolved in 350 parts by weight of ethyl cellosolve acetate and filtered through a 0.1 am Teflon filter to prepare a resist solution.

After applying the above resist solution onto a silicon wafer using a coater, it was betatized at 100"C for 90 seconds to a thickness of 1.1
A resist film of 7 μm was formed. This wafer was transferred to an i-line stepper N5R-1505i6A manufactured by Kon Co., Ltd., NA
= 0.45) and a test reticle, this wafer was subjected to PEB at 110'C for 60 seconds, and then exposed to 2.38% tetramethylammonium hydroxide aqueous solution at 23°C for 1 minute.

A positive pattern was obtained by development using the paddle method.

When the patterned wafer was taken out and the sensitivity was evaluated, it was found to be 140 mJ/cd, and when observed with an electron microscope, lines and spaces of 0.40 μm were resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 200.
When measured, it was 1.15 μm.

Koushi■ Copolymer of high-grade vinylphenol and styrene (molar ratio 5:5
) 100 parts by weight, 36 parts by weight of a quinonediazide compound in which 90% of trisphenol PA (manufactured by Mitsui Petrochemical) is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, 5 parts by weight of a sensitizer shown in formula (10) Diglyme part 3
A resist solution was prepared by dissolving 20 parts by weight and filtering through a 0.1 tIm Teflon filter.

After applying the above resist solution onto a silicon wafer using a coater, it was baked at 100'C for 90 seconds to a thickness of 1.
A resist film of 17 μm was formed. This wafer was exposed to light using an i-line stepper N5R-1505i6A and a test reticle.
After performing PEB for 60 seconds, a positive pattern was obtained by developing with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23° C. for 21 minutes using the paddle method.

When the patterned wafer was taken out and the sensitivity was evaluated, it was found to be 90 mJ/c, and when observed with an electron microscope, lines and spaces of 0.50 μm were resolved. The film thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 1.12 μm.

"Sword 1 Doctor" - Novolak resin 100 obtained by mixing m-cresol and p-cresol at a molar ratio of 5:5, adding formalin to this, and condensing it using an oxalic acid catalyst in a conventional manner.
Part by weight, 95% of 2.3,4.4'-tetrahydroxybenzophenone is 1,2-naphthoquinonediazide-
14 parts by weight of a quinonediazide compound which is an ester of 5-sulfonic acid, trisphenol PA (manufactured by Mitsui Petrochemical)
18 parts by weight of a quinonediazide compound, of which 90% is an ester of 1,2-nafdoquinonediazide-4-sulfonic acid.

10 parts by weight of the sensitizer shown in formula (19) was added to 380 parts by weight of ethyl lactate.
A resist solution was prepared by dissolving the solution in parts by weight and passing it through a 0.1μ Teflon filter.

After applying the above resist solution onto a silicon wafer using a coater, it was betatized at lOO''C for 90 seconds to a thickness of 1.1
A resist film of 7 μm was formed. This wafer was exposed using an i-line stepper N5R-1505i6A and a test reticle. Next, this wafer was subjected to PEB at 110°C for 60 seconds, and then developed with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23°C for 1 minute using the paddle method to obtain a positive pattern.

When the patterned wafer was taken out and the sensitivity was evaluated, it was 120 mJ/cd, and when observed with an electron microscope, lines and spaces of 0.40 μm were resolved. Measure the film thickness of the pattern using a film thickness meter Alpha Step 200.
When measured, it was 1.14 μm.

(Effects of the Invention) The positive resist composition of the present invention has excellent sensitivity, resolution, residual film rate, heat resistance, storage stability, etc.
Highly useful for microfabrication of μm or less.

Claims (1)

[Claims] (1) A positive resist composition comprising an alkali-soluble phenol resin, a quinonediazide sulfonic acid ester photosensitizer, and a compound represented by general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) R^1~R^4; H, halogen, alkyl group, alkenyl group or hydroxyl group of C_1~C_4 R^5, R^6; H, halogen or C_1~ C_4 alkyl group R^7 to R^1^0; H or C_1 to C_4 alkyl group