JPH02296249A - 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> is H, halogen, 1 - 4 C alkyl, alkenyl, alkoxy, or hydroxy. 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 quinonediazide sulfone of a compound represented by the following general formula (1) is used as the photosensitizer. This is achieved using a positive resist composition characterized by containing an acid ester.

1J R3R4 R1 to R5, hydrogen, haloken, alkyl group, alkenyl group, alkoxy group, or hydroxyl group of 01 to c4, provided that at least one is R6, R? , halogen, alkyl group or alkenyl 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, condensation reaction products of phenols and ketones, etc. products, vinylphenol polymers, isopropenylphenol polymers, 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, 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, and diphenyl ketone.

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-based polymer is selected from a homopolymer of isopropenylphenol, 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

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 (1)
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.

0■ ■ CI (3 0■ C11゜0H H It can be synthesized according to the conventional method described in "Photosensitive Polymer" by Hideo Inui (1980), 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 positive resist composition of the present invention is used after being dissolved in a solvent, and examples of the solvent include ketones such as acetin, methyl ethyl ketone, cyclohexanone, cyclopentanone, and cyclohexanol, n-propyl alcohol, and isopropyl alcohol.
~Alcohols such as propyl alcohol and n-butyl alcohol, ethylene glycol dimethyl ether,
Ethylene glycol diethyl ether, ethers such as dioxane, ethylene glycol diethyl ether,
Alcohol ethers such as ethylene glycol monoethyl ether, esters such as propyl formate, butyl formate, 6M propyl, 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 glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, halogenated hydrocarbons such as trichloroethylene, aromatic hydrocarbons such as toluene and xylene, dimethyl acetamide, dimethyl Examples include polar solvents such as formamide 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, 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 , quaternary ammonium salts such as trimethylhydroxymethylammonium hydroxide, 1-ethylhydroxymethylammonium hydroxide, and trimethylhydroxymethylammonium hydroxide.

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.

Implementation ■Novolac resin 100 obtained by mixing soil m-cresol and p-cresol at a molar ratio of 6=4, adding formalin to this, and condensing it using an oxalic acid catalyst in a conventional manner.
30 parts of a quinonediazide compound in which 90% or more of the -○H groups of compound (9) 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. A resist solution was prepared by filtration.

After applying the above resist solution onto 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-1505G6B 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.

Furthermore, the wafer with this pattern formed thereon was etched using a dry etching device DEM-451T (manufactured by Nikkei Anelva Co., Ltd.) at a power of 300 W, a pressure of 0.03 Torr, and a gas C.
I? When etching was performed at a 4/H=3/15 frequency of 13.56 MHz, it was observed that only the areas where there was no pattern were etched.

After coating the resist solution of Example 1 on a silicon wafer with a coater, it was betatized at 80°C for 90 seconds, and the resist solution of Example 1 was coated with a thickness of 1
．． A resist film of 2 μm was formed. This wafer was exposed using a g-line stepper N5R-1505G6E and a test reticle.

This wafer was then subjected to PEB (PO) at 110”C for 60 seconds.
3T EXPO3URHBAKING), then 2.
A positive pattern was obtained by developing with a 38% aqueous solution of tetramethylammonium hydroxide 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 1.20 μm.

Disaster ■Main M-cresol, p-cresol, and 3.5-xylenol were mixed in a molar ratio of 50:20:30, formalin was added to this, and the mixture was condensed using an oxalic acid catalyst in a conventional manner. 100 parts of novolac resin, compound (9)
33 parts of a quinonediazide compound in which 85% or more of the -〇H groups are esters of 1,2-naphthoquinonediazide-5-sulfonic acid are dissolved in 300 parts of ethyl lactate. ]μm
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 100'C for 90 seconds to a thickness of 1
．． A resist film of 17 μm was formed. G this wafer
Line stepper N5R-150506E (NA=0.54
) and a test reticle. Next 2.
A positive pattern was obtained by developing with a 38% aqueous solution of tetramethylammonium hydroxide 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. The film thickness of the pattern was 1.16 μm when measured using a film thickness meter Alpha Step 200.

Copolymer of 111 vinylphenol and styrene (mole ratio 6:4)
), 100 parts of compound (9)(7)-0HHBO2 or more is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, and 28 parts of a quinonediazide compound were dissolved in 320 parts of ethyl cellosolve acetate and filtered with a 0.1 um Teflon filter. A resist solution was prepared by filtration.

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
A positive pattern was obtained by development using the paddle method at .degree. C. for 1 minute.

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 80% or more of the OH groups of compound (13) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid. 28 parts of the compound was dissolved in 31 (l) of ethyl cellosolve acetate and filtered through a 0.1 μm Teflon filter to prepare a resist solution.

The resist solution was applied onto a silicon wafer using a coater, and then betatized for 90 seconds at IoO'C to form a resist film with a thickness of 1.17 μm. This wafer was transferred to a g-line stepper N5R-1505G6E (NA=0.5
4) and a test reticle were used for exposure. Next 2
．． A positive pattern was obtained by developing with a 38% aqueous solution of tetramethylammonium hydroxide at 23°C for 1 minute using the 2-buddle 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.

Novolac resin 100% obtained by mixing m-cresol and p-cresol at a molar ratio of 426, adding formalin to this, and condensing it using an oxalic acid catalyst in a conventional manner.
85% or more of -〇 H groups of compound (13) are 1,2-
A resist solution was prepared by dissolving 30 parts of a quinonediazide compound, which is an ester of naphthoquinonediazide-4 sulfonic acid, in 300 parts of diglyme 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 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 an i-line stesiver - ALS WAFER3TEP 2142i
(manufactured by GCA, NA=0.54) and a test reticle were used for exposure.

Next, a positive pattern was obtained by developing with a 2.38% aqueous tetramethylammonium hydroxide 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. The film thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 1.15 μm.

Implementation ■1 Copolymer of vinylphenol and styrene (mole ratio 6:4
) 100 parts, 80% or more of the -OH groups of compound (9) are 1,
30 parts of a quinonediazide compound, which is an ester of 2-naphthoquinonediazide-5-sulfonic acid, was dissolved in 300 parts of diglyme and filtered through a 0.1 μm Teflon filter to prepare a Regis i 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.
A resist film of 20 μm was formed. This wafer is transferred to i-line stepper ALS WAFER3TEP 2142.
Exposure was performed using i (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 was measured with a film thickness meter Alpha Step 200 and was found to be 1.15 μm.

Example ■ Novolac resin 100 obtained by mixing m-cresol and p-cresol at a molar ratio of 6=4, adding formalin to this, and condensing it using an oxalic acid catalyst in a conventional manner.
28 parts of a quinonediazide compound in which 85% or more of the -○H groups of compound (15) 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. A resist solution was prepared by filtration.

After applying the above resist solution onto 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 exposed using a g-line stencil N5R-1505G6E (NA=0.54) and a test reticle. Next 2.38
% tetramethylammonium hydroxide aqueous solution
A positive pattern was obtained by developing at °C for 1 minute using the 2-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.

Novolac resin 100 obtained by mixing m-cresol and p-cresol at a molar ratio of 4=6, adding formalin to this, and condensing the mixture in a conventional manner using an oxalic acid catalyst.
20 parts of a quinonediazide compound in which 60% or more of the -○H groups of compound (14) 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 1.1
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
A positive pattern was obtained by development using the paddle method at .degree. C. for 1 minute.

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 a hydrogenation reaction product (hydrogenation rate 35%) of a vinyl phenol polymer, 85% or more of the OH groups of compound (9) are esters of 1,2-naphthoquinonediazide-4-sulfonic acid. A resist solution was prepared by dissolving 30 parts of a certain quinonediazide compound in 300 parts of diglyme 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 betatized at 100'C for 90 seconds to a thickness of 1
．． A resist film of 00 μm was formed. An excimer laser device C2 that seals this wafer with krypton/fluorine
Exposure was performed using 926 (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 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 was measured with a film thickness meter Alpha Step 200 and was found to be 0.95 μm.

100 parts of the hydrogenation reaction product (hydrogenation rate 30%) of the vinyl phenol polymer on the implementation plate, 90% or more of the OH groups of compound (9) are esters of 1,2-naphthoquinonediazide-4-sulfonic acid. A resist solution was prepared by dissolving 28 parts of a quinonediazide compound in 300 parts of diglyme and filtering the solution through a 0.111 m Teflon filter.

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 1.0
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 is measured using a film thickness meter Alpha Step 200. :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, 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) 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. etc. ▼ R^6, R^7: Halogen, alkyl group or alkenyl group n = 0, 1 or 2