JPH041653A - Positive type resist composition - Google Patents

Abstract

PURPOSE:To improve various characteristics, such as sensitivity, resolution, residual film rate, heat resistance, and preservable stability by incorporating the quinonediazide sulfonate of a specific compd. as a photosensitive agent into the above compsn. CONSTITUTION:The quinonediazide sulfonate of the compd. expressed by formula I is incorporated as the photosensitive agent into this compsn. In the formula I, A denotes an alkylene group, substd. alkylene group alkenyl group or substd. alkenyl group; R<1> to R<6> denote hydrogen, halogen, 1 to 4C alkyl group, 1 to 4C alkoxy group or hydroxyl group. The positive type resist compsn. which excels in the various characteristics, such as sensitivity, resolution, residual film rate, heat resistance, and preservable stability and is suitable for fine working particularly for <=1mum is obtd. in this way.

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 necessary for manufacturing semiconductor devices, magnetic bubble memory devices, integrated circuits, etc. The present invention relates to a resist composition.

(Prior art) When manufacturing semiconductors, a resist is applied to the surface of a silicon wafer to create a photoresist film, 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 superior resolution and is therefore considered to be able to sufficiently cope with high integration of semiconductors. Currently, the positive resist compositions commonly used in this field are:
It consists of novolak resin and quinonediazide compound.

However, conventional positive resist compositions lack sensitivity,
Satisfactory results have not always been obtained in terms of resolution, residual film rate, heat resistance, storage stability, and other properties, and improvements in performance are strongly desired.

(Problems to be Solved by the Invention) The purpose of the present invention is to solve the above-mentioned drawbacks of the prior art, improve sensitivity,
The object of the present invention is to provide a 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 a positive resist composition containing an alkali-soluble phenol resin and a photosensitizer, in which quinonediazide sulfone of a compound represented by the following general formula (I) is used as the photosensitizer. This is achieved using a positive resist composition characterized by containing an acid ester.

(A: Alkylene group, substituted alkylene group, alkenyl group or substituted alkenyl group R1, R1, hydrogen, halogen, CI"" C4 alkyl group, CI-C4 alkoxy group or hydroxyl group, which may be the same or different ) The alkali-soluble phenolic resin used in the present invention includes, for example, condensation reaction products of phenols and aldehydes, condensation reaction products of phenols and ketones, vinylphenol polymers, isopropenylphenol polymers, etc. and hydrogenation reaction products of these phenolic resins.

Here, specific examples of phenols used include phenol, cresol, xylenol, ethylphenol,
-valent phenols such as propylphenol, butylphenol, phenylphenol, redulucinol,
Pyrocatechol, hydroquinone, bisphenol A1
Examples include polyhydric phenols such as pyrogallol.

Further, specific examples of aldehydes include formaldehyde, acetaldehyde, benzaldehyde, and terephthalaldehyde.

Furthermore, specific examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone, and the like.

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

Also, vinyl phenol! Combined Ha, l:'2/L/
7 enol homopolymers and copolymers of vinylphenol and copolymerizable components. 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 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.

These phenolic resin hydrogenation reaction products can be prepared by any known method, such as by dissolving the phenolic resin in an organic solvent and in the presence of a homogeneous or heterogeneous hydrogenation catalyst. can be prepared by introducing hydrogen.

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

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 resolution, storage stability, heat resistance, etc., as necessary. Copolymers, copolymers of alkenes and maleic anhydride, vinyl alcohol polymers, vinyl pyrrolidone polymers, rosin shellac, etc. can be added. The amount added is 100% of the above alkali-soluble phenolic resin.
The amount is 0 to 50 parts by weight, preferably 5 to 20 parts by weight.

The photosensitizer used in the present invention has the above-mentioned maximum (I)
It is not particularly limited as long as it is a quinonediazide sulfonic acid ester of a compound represented by the formula. As a specific example, the ester moiety is 1,2-benzoquinonediazide-
4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester, 2,1-naphthoquinonediazide-4-sulfonic acid ester, 2,1-naphthoquinonediazide Examples include compounds such as quinonediazide-5-sulfonic acid ester and other sulfonic acid esters of quinonediazide derivatives.

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

H C.I.

The photosensitizer in the present invention is produced by an esterification reaction between a compound represented by (I) and a quinone diazitosulfonic acid compound. It is easily synthesized according to the conventional method described in Gentabe Nagamatsu and Hideo Inui, "Photosensitive Polymer" (1980), Kodansha (Tokyo), etc.

The photosensitizer in the present invention can be used alone.
A mixture of more than one species may be used. The total amount of 6 units of photosensitizer is
The amount 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 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, cyclopentanone, cyclohexanol, n-propyl alcohol, 1
Alcohols such as so-propyl alcohol and n-butyl alcohol, ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and dioxane, alcohol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, propyl formate, butyl formate , esters such as propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl lactate, ethyl lactate, cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, butyl cellosolve acetate, etc. Propylene glycols such as cellosolve esters, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol motubutyl ether, diethylene glycol 7-methyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol Examples include diethylene glycols such as diethyl ether and diethylene glycol methyl ethyl ether, halogenated hydrocarbons such as trichloroethylene, aromatic hydrocarbons such as toluene and xylene, and polar solvents such as dimethylacetamide, dimethylformamide, and N-methylacetamide. .

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

The positive resist composition of the present invention may contain compatible additives such as surfactants, storage stabilizers, sensitizers, anti-striation agents, plasticizers, and antihalation agents, as necessary. I can do it.

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. Note that parts and percentages in the examples are based on weight unless otherwise specified.

Novolac resin 100 is obtained by mixing m-cresol and p-cresol at a molar ratio of 6=4, adding formalin to this, and condensing the mixture in a conventional manner using an oxalic acid catalyst.
32 parts of a quinonediazide compound in which 80% of the -OH groups of the compound (1) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid were dissolved in 320 parts of ethyl cellosolve acetate and filtered with a 0.1 μm Teflon filter. was filtered to prepare a resist solution.

After applying the above resist solution on a silicon wafer with a coater, it was baked at 100"C for 90 seconds to a thickness of 1.1
A resist film of 7 μm was formed. This wafer was placed in a g-line stepper N5R-1505G6B manufactured by Kon Co., Ltd., N^=
0.54) and 0 exposed using a test reticle.
Next, a positive pattern was obtained by developing with a 2.38% aqueous tetramethylammonium hydroxide solution at 23° C. for 11 minutes using the paddle method.

When the patterned wafer was taken out and observed under an electron microscope, lines and spaces of 0.50 pm were resolved. When the film thickness of the pattern was measured using a film thickness meter Alpha Step 200 (manufactured by Tenco), it was 1.15.
It was μm.

Furthermore, the wafer with this pattern formed thereon was etched using a dry etching device OEM-4517 (manufactured by Nichiden Anelva Co., Ltd.) at a power of 300 W, a pressure of 0.03 Torr, a gas CF, /H=3/1, and a frequency of 13.56 M)lz.
When etching was performed, it was observed that only the areas where there was no pattern were etched.

After coating the resist solution of Comparative Example 1 on a silicon wafer with a coater, it was baked at 80°C for 90 seconds to give a thickness of 1
．． A resist film of 2 μm was formed. Is this wafer a G-line stepper NSI? Exposure was performed using -1505G6E and a test reticle. Next, rotate this wafer at 110°
FEB for 60 seconds at C (PO5T EχPO5UREBI
KrNG) and then developed using a 2.38% aqueous solution of tetramethylammonium hydroxide at 23° C. for 11 minutes using the paddle method to obtain a positive pattern.

When the patterned wafer was taken out and observed under an electron microscope, lines and spaces of 0.40 gm were resolved. The M thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 1.20 μm.

A novolak obtained by mixing m-cresol, p-cresol, and 3,5-xylenol in a molar ratio of 50:20:30, adding formalin to this, and condensing the mixture using an oxalic acid catalyst in a conventional manner. 100 parts of resin, the above compound (
30 parts of a quinonediazide compound in which 80% of one group in 3)-〇) is an ester of 1.2-naphthoquinonediazide-5-sulfonic acid is dissolved in 300 parts of ethyl lactate to give a 0.1μ
A resist solution was prepared by filtration with a Teflon filter.

After applying the above resist solution onto a silicon wafer using a coater, it was betatized at 90°C for 90 seconds to a thickness of 1.17 μm.
A resist film of m was formed. This wafer was exposed using a g-line stepper N5R-1505G6E (N^-0,54) and a test reticle. Next, this wafer was subjected to PEB at 110°C for 60 seconds, and then heated to 23°C with a 2.38% tetramethylammonium hydroxide aqueous solution.
A positive pattern was obtained by developing for 21 minutes by the paddle method.

When the patterned wafer was taken out and observed under an electron microscope, lines and spaces of 0.50 μm were resolved. The film thickness of the pattern was 1.16 μm when measured using a film thickness meter Alpha Step 200.

Pig 1■ Evinylphenol and styrene copolymer (mole ratio 6:4
) 100 parts, 75% of the compound (3)(7)-08 group
A resist solution was prepared by dissolving 35 parts of a quinonediazide compound, which is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, in ethyl cellosolve acetate 320 and filtering the solution through a 0.1 μm Teflon filter.

After applying the above resist solution onto a silicon wafer using a coater, it was baked at 90°C for 90 seconds to a thickness of 1.17 μm.
A resist film was formed. This wafer was exposed using a g-line stepper N5R4505G6E (NA=0.54) and a test reticle. Next, this wafer was subjected to PHB at 110'C for 60 seconds, and then heated at 23°C with a 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 observed under 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 1.10 μm.

Novolak 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.
28 parts of a quinonediazide compound in which 78% of the -○H groups of the compound (1) are esters of 1.2-naphthoquinonediazide-4-sulfonic acid were dissolved in 300 parts of diglyme and filtered with a 0.1 μm Teflon filter. A resist solution was prepared by filtration.

After applying the above resist solution onto a silicon wafer using a coater, it was baked at 90°C for 90 seconds to a thickness of 1.20 mm.
A resist film of μm thickness was formed. This wafer was transferred to an i-line stepper ALS WAFER5TEP 2142i (GC
Exposure was performed using a test reticle (NA 0.54) manufactured by Company A.

Next, after PEBing this wafer at 110'C for 60 seconds,
A positive pattern was obtained by developing with a 2.38% aqueous tetramethylammonium hydroxide solution at 23° C. for 11 minutes using the paddle method.

When the patterned wafer was taken out and observed under 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 1.15 μm.

(Effects of the Invention) The resist composition of the present invention has excellent properties such as sensitivity, resolution, residual film rate, heat resistance, and storage stability, and is therefore particularly suitable for microfabrication of 1 μm or less.

Claims (1)

[Claims] (1) A positive resist composition containing an alkali-soluble phenol resin and a photosensitizer, which is characterized by containing a quinonediazide sulfonic acid ester of a compound represented by the following general formula (I) as the photosensitizer. Resist composition. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (A: Alkylene group, substituted alkylene group, alkenyl group, or substituted alkenyl group R^1~R^6: Hydrogen, halogen, alkyl group of C_1~C_4, C_1~ C_4 alkoxy group or hydroxyl group, which may be the same or different)