JPH02296248A - Positive type resist composition - Google Patents

Abstract

PURPOSE:To obtain a positive type photoresist superior in various characteristics, such as sensitivity, resolution, residual film rate, heat resistance, and storage stability, and adapted to microfabrication by incorporating an alkali-soluble phenol resin and as a photosensitive agent a specified quinonediazidosulfonic acid ester. CONSTITUTION:The positive type resist composition contains the alkali-soluble phenol resin and as the photosensitive agent the quinonediazidosulfonic acid ester represented by formula I in which each of R<1> - R<5> ks H, halogen, 1 - 4 C alkyl, alkenyl, alkoxy, or hydroxy and A is -S-, -O-, or the like. The alkali- soluble phenol resin to be used is embodied by the condensation reaction products between phenols and aldehydes or ketones and the like, thus permitting various characteristics, such as sensitivity, resolution, residual film rate, heat resistance, and storage stability, and especially adapted to submicron microfabrication.

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 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.

(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 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 a compound represented by the following - Funato (1) is used as the photosensitizer. This is achieved by a positive resist composition characterized by containing a quinonediazide sulfonic acid ester.

R1, R5, hydrogen, halogen, C0 to C4 alkyl group, alkenyl group, alkoxy group or hydroxyl group, provided that at least one is R6, halogen, alkyl group or alkenyl group R7R8
, hydrogen, alkyl group, alkenyl group, or phenyl group n=0.1 or 2 Examples of the alkali-soluble phenol resin used in the present invention include condensation reaction products of phenols and aldehydes, phenols and ketones, etc. Examples include condensation reaction products of, vinylphenol polymers, isopropenylphenol polymers, and hydrogenation reaction products of these phenol resins.

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

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

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

These condensation reactions can be carried out according to conventional methods.

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, 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.

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

These alkali-soluble phenolic resins may be used alone, or 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 has the general formula (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 1.2benzoquinonediazide-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 5-sulfonic acid esters and other sulfonic acid esters of quinonediazide derivatives.

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

CI(3 H C.I.

H H3 ■ The photosensitizer in the present invention can be synthesized by an esterification reaction of the compound represented by the general formula (I) and a quinonediazide sulfonic acid compound, It can be synthesized according to the conventional method described in Molecule J (1980) Kodansha (Tokyo).

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 positive resist composition of the present invention is used by being dissolved in a solvent, and examples of the solvent include acetone, methyl ethyl ketone,
Ketones such as cyclohexanone, cyclopentanone, cyclohexanol, n-propyl alcohol, 1so-
Alcohols such as 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, phthyl oxalate, 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. Esters, 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 glycol monomethyl ether,
Diethylene glycols such as diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methylethyl ethyl, halogenated hydrocarbons such as trichloroethylene, aromatic hydrocarbons such as toluene and xylene, dimethylacetamide, dimethylformamide, N - Polar solvents such as methylacetamide, etc. can be mentioned.

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, and plasticizers, if necessary.

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 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.
30 parts of a quinonediazide compound in which 90% or more of the -○H groups of compound (13) are esters of L2-naphthoquinonediazide-5 sulfonic acid were dissolved in 320 parts of ethyl cellosolve acetate and filtered with a 0.1 μm Teflon filter. A resist solution was prepared.

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 on a g-line stepper N5R-150506E manufactured by Kon Co., Ltd., NA=0.
．． 54) and a test reticle. Next, 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 observed under an electron microscope, lines and spaces of 0°45 μm were resolved. The film thickness of the pattern is 1.15 μm when measured with a film thickness meter Alpha Step 200 (manufactured by Tenco).
Met.

Roughly, the wafer on which this pattern was formed was dry-etched using a DEM-451T (manufactured by Nikkei Anelva Co., Ltd.).
using a power of 300 W, a pressure of 0.03 Torr, and a gas of CF4/H=3/1. When etching was performed at a frequency of 13.56 M11z, it was observed that only the areas where there was no pattern were etched.

Disaster Cause I After applying the resist solution of Example 1 onto a silicon wafer using a coater, it was plated at 80°C for 90 seconds to a thickness of 1.
．． A resist film of 2 μm was formed. This wafer was exposed using a g-line stencil N5R-1505G6E and a test reticle.

This wafer was then subjected to PEB (PO) at 110°C for 60 seconds.
3T EXPO5URE BAKING), then 2
．． A positive pattern was obtained by developing with a 38% aqueous tetramethylammonium hydroxide solution at 23°C for 21 minutes using the paddle method.

When the patterned wafer was taken out and observed under 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 1.20 μm.

It was obtained by mixing m-cresol, p-cresol, and 3,5-gislenol in a molar ratio of 50:20:30, adding formalin to this, and condensing it using an oxalic acid catalyst by a conventional method. 100 parts of novolak resin and 33 parts of a quinonediazide compound in which 85% or more of the -〇H groups of compound (13) are esters of L2-naphthoquinonediazide-5-sulfonic acid were dissolved in 300 parts of ethyl lactate and filtered with a 0.1 μm Teflon filter. was filtered 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 exposed using a g-line stepper N5R-150506E (NA=0.54) and a test reticle. Next 2.38
% tetramethylammonium hydroxide aqueous solution
'C: Developed by paddle method for 1 minute to obtain a positive pattern.

When the patterned wafer was taken out and observed under 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 1.16 μm.

Copolymer of vinylphenol and styrene (mole ratio 6:4)
) 100 parts, 80% or more of -〇H groups of compound (13) are 1
, 2-naphthoquinonediazide-5-sulfonic acid ester was dissolved in 320 parts 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 baked at 100'C for 90 seconds to a thickness of 1
．． A resist film of 17 μm was formed. G this wafer
ta stepper N5R-1505G6E (NA=0.5
4) and a test reticle were used for exposure. Next 2
．． 23'C for 1 minute with 38% tetramethylammonium hydroxide aqueous solution. A positive pattern was obtained by development using the paddle method.

When the patterned wafer was taken out and observed under 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 1.10 μm.

100 parts of a copolymer of isopropenylphenol and styrene (molar ratio 7:3), quinonediazide in which 90% or more of the ○H groups of compound (26) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid. 28 parts of the compound was dissolved in 310 parts 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 exposed using a g-line stencil NSR-150506E (NA=0.54) and a test reticle. Next 2.38
% tetramethylammonium hydroxide aqueous solution
℃ for 1 minute 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 0.45 μm were resolved. The film thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 1.10 μm.

A novolac resin 100 obtained by mixing m-cresol and p-cresol in a molar ratio of 4:6, adding formalin to this, and condensing it using an oxalic acid catalyst in a conventional manner.
30 parts of a quinonediazide compound in which 85% or more of -○H groups of compound (26) are esters of 1,2-naphthoquinonediazide-4 sulfonic acid are dissolved in 300 parts of diglyme. A resist solution was prepared by filtering through a 1 μm Teflon filter.

After applying the above resist solution onto a silicon wafer using a coater, it was betatized at lOOoC for 90 seconds to a thickness of 1.2
A resist film of 0 μm was formed. This wafer is transferred to i-line stepper ALS WAFER3TEP 2142i.
(manufactured by GCA, NA=0.54) and a test reticle were used for exposure. Next, with a 2.38% tetramethylammonium hydroxy I.' 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 observed under 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 1.15 μm.

Disaster nail ↑ Co-1fZ combination of vinylphenol and styrene (mo/l/
ratio 6:4) 100 parts, -011 group 85 of compound (26)
A resist solution was prepared by dissolving 30 parts of a quinonediazide compound of which % or more was an ester of 1.2-naphthoquinonediazide-5-sulfonic acid in 300 parts of diglyme and filtering the solution with a 0.1 μm Teflon filter.

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 1.2
A resist film of 0 μm was formed. This wafer is transferred to i-line stepper ALS WAFER3TEP 2142i.
(NA=O154) and a test reticle were used for exposure. Next, a positive pattern was obtained by developing with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23°C for 21 minutes by the pathol method.

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

Novolac resin 100 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.
Quinonediazide compound 28, in which 90% or more of the -〇H groups of compound (28) are esters of 1,2-naphthoquinonediazide-53sulfonic acid
1 part was dissolved in 320 parts of ethyl cellosolve acetate and 0
．． A resist solution was prepared by filtering through a 1 μm Teflon filter.

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 exposed using a g-line stepper N5R-1505G6E (NA=0.54) and a test reticle. Next 2.38
% tetramethylammonium hydroxide aqueous solution
"C. Developed for 1 minute 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 0.45 μm were resolved. The film thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 1.15 μm.

Novolac resin 100 obtained by mixing m-cresol and p-cresol at a molar ratio of 6=4, adding formalin to this, and condensing the mixture using an oxalic acid catalyst in a conventional manner.
20 parts of a quinonediazide compound in which 80% or more of the -○H groups of compound (28) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid are dissolved in 300 parts of ethyl lactate and filtered with a 0.1 μm Teflon filter. A resist solution was prepared.

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 1.17 cm.
A resist film of μm thickness was formed. This wafer was exposed using a g-line stepper N5R-1505C; 6E (NA=0.54) and a test reticle. Next 2.38
% tetramethylammonium hydroxide aqueous solution
'C: Developed by paddle method for 1 minute to obtain a positive pattern.

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

- 100 parts of hydrogenation reaction product of vinylphenol polymer [hydrogenation rate 35%], -〇H group 85 of compound (28)
A resist solution was prepared by dissolving 30 parts of a quinonediazide compound of which % or more was an ester of 1.2-naphthoquinonediazide-4-sulfonic acid in 300 parts of diglyme and filtering the solution with a 0.1 μm Teflon filter.

After coating the above resist solution on a silicon wafer with coke, it was betatized at 100°C for 90 seconds to a thickness of 1.0
A resist film of 0 μm was formed. Eximer laser device C = 29 which sealed this wafer with krypton/fluorine
26 (manufactured by Hamamatsu Photonics) and a test mask. Next, a positive pattern was obtained by developing with a tetramethylammonium hydroxide aqueous solution at 23°C for 1 minute using the paddle method.

When the patterned wafer was taken out and observed under an electron microscope, lines and spaces of 0.45 μm were resolved. When the film thickness of the pattern was measured with a film thickness meter Alpha Step 200, it was 0.95 μm. On the test chamber: 100 parts of hydrogenation reaction product of vinyl phenol polymer (hydrogenation rate 30%), compound (13) -〇H group 90
A resist solution was prepared by dissolving 28 parts of a quinonediazide compound of which % or more was an ester of 1.2-naphthoquinonediazide-4-sulfonic acid in 300 parts of diglyme and filtering the solution with a 0.1 μm Teflon filter.

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 1.0
A resist film of 0 μm was formed. This wafer was exposed to light using a far ultraviolet irradiation device PLA-521FA (manufactured by Canon) and a test mask. Next, a positive pattern was obtained by developing with a tetramethylammonium hydroxide aqueous solution at 23°C for 1 minute using the paddle method.

When the patterned wafer was taken out and observed under an electron microscope, lines and spaces of 0.40 μm were resolved. The film thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 0.92 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, so it is particularly suitable for microfabrication of 1 μm or less.

Patent applicant: Zeon Corporation

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) R^1~R^5; Hydrogen, halogen, C_1~C_4 alkyl groups, alkenyl groups, alkoxy groups, or hydroxyl groups, provided that at least one of them is ▲Mathematical formulas, chemical formulas, tables, etc. There are ▼ A; -S-, -O-, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, Chemical formula,
There are tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ R^6; Halogen, alkyl group or alkenyl group R^7
, R^8; hydrogen, alkyl group, alkenyl group or phenyl group n=0, 1 or 2