JP2640382B2 - Positive resist composition - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a positive resist composition, and more particularly, to a positive resist composition for fine processing required for manufacturing semiconductor devices, magnetic bubble memory devices, integrated circuits and the like. The present invention relates to a resist composition.

(Prior Art) When manufacturing a semiconductor, a resist is applied to the surface of a silicon wafer to form a photosensitive film, which is irradiated with light to form a latent image, and then developed to form a negative or positive image. 2. Description of the Related Art A semiconductor element is formed by a lithography technique.

Conventionally, as a resist composition for forming a semiconductor element, a negative resist comprising a cyclized polyisoprene and a bisazide compound has been known. However, since this negative resist is developed with an organic solvent, it has a disadvantage that it cannot cope with the manufacture of a highly integrated semiconductor because it has a large swelling and a limited resolution.

On the other hand, it is considered that the positive resist composition is superior in resolution to the negative resist composition, and therefore can sufficiently cope with high integration of semiconductors. Currently, a positive resist composition generally used in this field comprises a novolak resin and a quinonediazide compound.

However, conventional positive resist compositions have not always achieved satisfactory results in various properties such as sensitivity, resolution, residual film ratio, heat resistance, and storage stability, and there is a strong demand for improved performance. .

(Problems to be Solved by the Invention) An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide excellent properties such as sensitivity, resolution, remaining film ratio, heat resistance, and storage stability, particularly 1 μm or less. An object of the present invention is to provide a positive resist composition suitable for fine processing.

(Means for Solving the Problems) An object of the present invention is to provide a positive resist composition containing an alkali-soluble phenol resin and a photosensitizer, wherein the photosensitizer comprises all phenols of a compound represented by the following general formula (I). This is achieved by a positive resist composition characterized in that 90% or less of the hydroxyl groups contain a quinonediazidesulfonic acid esterified compound.

(A: alkylene group, substituted alkylene group, alkenylene group, substituted alkenylene group, arylene group or substituted arylene group R ^{1 to} R ⁸ : hydrogen, halogen, C _{1 to} C ₄ alkyl group, C _{1 to} C ₄
An alkoxy group, an alkenyl group or a hydroxyl group of C ₁ -C _4, as the alkali-soluble phenolic resin used in may also be) the present invention be the same or different, for example, condensation products of phenols and aldehydes And a condensation reaction product of a phenol and a ketone, a vinylphenol-based polymer, an isopropenylphenol-based polymer, and a hydrogenation reaction product of these phenolic resins.

Here, specific examples of the phenols used include phenol, cresol, xylenol, ethylphenol, propylphenol, butylphenol, phenylphenol, monovalent phenols such as resorcinol, pyrocatechol, hydroquinone, bisphenol A, pyrogallol, and the like. And polyhydric phenols.

Specific examples of aldehydes include formaldehyde, acetaldehyde, benzaldehyde, terephthalaldehyde, and the like.

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

These condensation reactions can be performed according to a conventional method such as bulk polymerization or solution polymerization.

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

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

The hydrogenation reaction products of these phenolic resins can be prepared by any known method, for example, by dissolving the phenolic resin in an organic solvent, and adding a phenolic resin in the presence of a homogeneous or heterogeneous hydrogenation catalyst. , By introducing hydrogen.

As these alkali-soluble phenol resins, those whose molecular weight distribution is controlled by reprecipitation separation or the like can be used. These resins may be used alone or in combination of two or more.

In the positive resist composition of the present invention, if necessary,
In order to improve the resolution, storage stability, heat resistance, etc., for example, a copolymer of styrene and acrylic acid, methacrylic acid or maleic anhydride, a copolymer of alkene and maleic anhydride, vinyl alcohol Coalescence, vinylpyrrolidone polymer, rosin shellac and the like can be added. The amount added is 100% of the alkali-soluble phenol resin.
The amount is 0 to 50 parts by weight, preferably 5 to 20 parts by weight based on parts by weight.

The photosensitizer used in the present invention is one of the total phenolic hydroxyl groups of the compound represented by formula (I).
There is no particular limitation as long as 90% or less of the compound is a quinonediazidesulfonic acid esterified compound. As specific examples, 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-5-sulfonic acid ester, and other sulfonic acid esters of quinonediazide derivatives.

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

The photosensitizer in the present invention can be synthesized by an esterification reaction between the compound represented by the general formula (I) and a quinonediazidesulfonic acid compound.
It can be synthesized according to a conventional method described in Hideo Inui, “Photosensitive Polymers” (1980) Kodansha (Tokyo).

The photosensitive agent in the present invention may be used alone or in combination of two or more. The amount of the photosensitive agent 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 is impossible to form a pattern. If the amount exceeds 100 parts by weight, an afterimage tends to remain.

The positive resist composition of the present invention is used by dissolving it in a solvent. As the solvent, ketones such as acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone and cyclohexanol, n-propyl alcohol, is
o-propyl alcohol, alcohols such as n-butyl alcohol, ethylene glycol dimethyl ether,
Ethylene glycol diethyl ether, ethers such as dioxane, ethylene glycol monomethyl ether, alcohol ethers such as ethylene glycol monoethyl ether, propyl formate, butyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, Ethyl butyrate, methyl lactate, esters such as ethyl lactate, cellosolve esters such as cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, butyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether,
Propylene glycol monomethyl ether acetate,
Propylene glycol monoethyl ether acetate,
Propylene glycols such as propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycols such as diethylene glycol methyl ethyl ether, halogenated hydrocarbons such as trichloroethylene, toluene,
Examples thereof include aromatic hydrocarbons such as xylene, polar solvents such as dimethylacetamide, dimethylformamide, and N-methylacetamide. These are 2
You may mix and use more than one type.

The positive resist composition of the present invention may contain, if necessary, compatible additives such as a surfactant, a storage stabilizer, a sensitizer, a striation inhibitor, a plasticizer, and an antihalation agent. Can be.

As the developer of the positive resist composition of the present invention, an aqueous alkali solution is used.Specifically, sodium hydroxide, potassium hydroxide, sodium silicate, inorganic alkalis such as ammonia, ethylamine, propylamine and the like are used. Primary amines, diethylamine, secondary amines such as dipropylamine, trimethylamine, tertiary amines such as triethylamine, diethylethanolamine,
Alcohol amines such as triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, and trimethylhydroxyethylammonium hydroxide. Can be

Further, if necessary, a suitable amount of a water-soluble organic solvent such as methanol, ethanol, propanol, and ethylene glycol, a surfactant, a storage stabilizer, a resin dissolution inhibitor, and the like can be added to the alkaline aqueous solution.

(Example) Hereinafter, the present invention will be described more specifically with reference to examples. The parts and percentages in the examples are on a weight basis unless otherwise specified.

Example 1 m-Gresol and p-cresol were mixed at a molar ratio of 4: 6, to which formalin was added, and a novolak resin 100 obtained by condensation using an oxalic acid catalyst in a conventional manner.
Part of a quinonediazide compound in which 90% of the -OH groups of the compound (14) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid.
And dissolved through a 0.1 μm Teflon filter to prepare a resist solution.

The resist solution was applied on a silicon wafer by a coater, and baked at 100 ° C. for 90 seconds to form a resist film having a thickness of 1.17 μm. This wafer is g-line stepper
Exposure was performed using NSR-1505G6E (manufactured by Nikon Corporation, NA = 0.54) and a test reticle. Next, it was developed with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 1 minute by a paddle method to obtain a positive pattern.

When the wafer on which the pattern was formed was taken out and observed with an electron microscope, a line and space of 0.50 μm was resolved. The film thickness of the pattern was 1.15 μm when measured with a film thickness meter Alpha Step 200 (manufactured by Tenko).

Further, the wafer on which this pattern was formed was subjected to dry etching equipment DEM-451T (manufactured by Nidec Anelva), power 300 W, pressure 0.03 Torr, gas CF ₄ / H = 3/1, frequency
When etching was performed at 13.56 MHz, it was observed that etching was performed only where there was no pattern.

Example 2 The resist solution of Example 1 was applied on a silicon wafer by a coater, and baked at 90 ° C. for 90 seconds to obtain a thickness of 1.2 μm.
m of the resist film was formed. This wafer was exposed using a g-line stepper NSR-1505G6E and a test reticle. Next, this wafer is subjected to PEB (POST EXP
(OSUREBAKING), and developed with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 1 minute by a paddle method to obtain a positive pattern.

When the wafer on which the pattern was formed was taken out and observed with an electron microscope, a line and space of 0.40 μm was resolved. The film thickness of the pattern was 1.20 μm when measured with a film thickness meter Alpha Step 200.

Example 3 m-cresol, p-cresol and 3,5-xylenol were mixed at a molar ratio of 50:20:30, formalin was added thereto, and novolak obtained by condensation using an oxalic acid catalyst in a conventional manner. 100 parts of resin, 80% of -OH group of the compound (16)
Is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, 32 parts of quinonediazide compound
And dissolved through a 0.1 μm Teflon filter to prepare a resist solution.

The resist solution was applied on a silicon wafer by a coater and baked at 90 ° C. for 90 seconds to form a resist film having a thickness of 1.17 μm. This wafer is converted to g-line stepper NSR
Exposure was performed using -1505G6E (NA = 0.54) and a test reticle. Next, the 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 by a paddle method to obtain a positive pattern.

When the wafer on which the pattern was formed was taken out and observed with an electron microscope, a line and space of 0.45 μm was resolved. The film thickness of the pattern was 1.16 μm as measured by a film thickness meter Alpha Step 200.

Example 4 Copolymer of vinylphenol and styrene (molar ratio 6:
4) 100 parts, 28 parts of a quinonediazide compound in which 90% of the -OH groups of the compound (13) are esters of 1,2-naphthoquinone azide-5-sulfonic acid, was treated with ethyl cellosolve acetate.
It was dissolved in 320 parts and filtered through a 0.1 μm Teflon filter to prepare a resist solution.

The resist solution was applied on a silicon wafer by a coater and baked at 90 ° C. for 90 seconds to form a resist film having a thickness of 1.17 μm. This wafer is converted to g-line stepper NSR
Exposure was performed using -1505G6E (NA = 0.54) and a test reticle. Next, the 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 by a paddle method to obtain a positive pattern.

When the wafer on which the pattern was formed was taken out and observed with an electron microscope, a line and space of 0.50 μm was resolved. The film thickness of the pattern was 1.10 μm when measured with a film thickness meter Alpha Step 200.

Example 5 100 parts of a copolymer of isopropenylphenol and styrene (molar ratio 7: 3), wherein 90% of the -OH groups of the compound (1) were 1,
A resist solution was prepared by dissolving 32 parts of a quinonediazide compound which is an ester of 2-naphthoquinonediazide-5-sulfonic acid in 310 parts of ethyl cellosolve acetate and filtering through a 0.1 μm Teflon filter.

The resist solution was applied on a silicon wafer with a coater and baked at 80 ° C. for 90 seconds to form a resist film having a thickness of 1.17 μm. This wafer is converted to g-line stepper NSR
Exposure was performed using -1505G6E (NA = 0.54) and a test reticle. Next, PEB this wafer at 110 ° C for 60 seconds,
2.38% aqueous solution of tetramethylammonium hydroxide
Developing by a paddle method at 23 ° C. for 1 minute to obtain a positive pattern.

When the wafer on which the pattern was formed was taken out and observed with an electron microscope, a 0.55 μm line & space was resolved. The film thickness of the pattern was 1.10 μm when measured with a film thickness meter Alpha Step 200.

Example 6 Novolak resin 100 obtained by mixing m-cresol and p-cresol at a molar ratio of 4: 6, adding formalin thereto, and condensing by an ordinary method using an oxalic acid catalyst.
Part, a quinonediazide compound in which 80% of the -OH groups of the compound (14) are esters of 1,2-naphthoquinonediazide-4-sulfonic acid was dissolved in 300 parts of diglyme, and 0.1 µ
Then, the solution was filtered through a Teflon filter of m to prepare a resist solution.

The resist solution was applied on a silicon wafer with a coater, and baked at 90 ° C. for 90 seconds to form a resist film having a thickness of 1.20 μm. This wafer is i-line stepper AL
Exposure was performed using SWAFERSTEP2142i (NA = 0.54, manufactured by GCA) and a test reticle.

Next, the 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 by a paddle method to obtain a positive pattern.

When the wafer on which the pattern was formed was taken out and observed with an electron microscope, a line and space of 0.45 μm was resolved. The film thickness of the pattern was 1.15 μm as measured by a film thickness meter Alpha Step 200.

Example 7 Copolymer of vinylphenol and styrene (molar ratio: 6:
4) A 0.1 μm Teflon filter prepared by dissolving 100 parts of a quinonediazide compound in which 85% of the —OH groups of the compound (16) are 1,2-naphthoquinonediazide-5-sulfonic acid esters in 300 parts of diglyme. To prepare a resist solution.

The resist solution was applied on a silicon wafer by a coater, and baked at 100 ° C. for 90 seconds to form a resist film having a thickness of 1.20 μm. This wafer is i-line stepper AL
Exposure was performed using S WAFERSTEP2142i (NA = 0.54) and a test reticle. Next, the wafer is heated at 110 ° C for 60 seconds.
After the EB, it was developed with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 1 minute by a paddle method to obtain a positive pattern.

When the wafer on which the pattern was formed was taken out and observed with an electron microscope, a 0.55 μm line & space was resolved. The film thickness of the pattern was 1.15 μm as measured by a film thickness meter Alpha Step 200.

Example 8 m-cresol and p-cresol were mixed at a molar ratio of 6: 4, to which formalin was added, and a novolak resin 100 obtained by condensation using an oxalic acid catalyst in a conventional manner.
Part of a quinonediazide compound in which 85% of the -OH groups of the compound (17) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid.
And dissolved through a 0.1 μm Teflon filter to prepare a resist solution.

The resist solution was applied on a silicon wafer by a coater, and baked at 100 ° C. for 90 seconds to form a resist film having a thickness of 1.17 μm. This wafer is g-line stepper
Exposure was performed using NSR-1505G6E (NA = 0.54) and a test reticle. Next, it was developed with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 1 minute by a paddle method to obtain a positive pattern.

When the wafer on which the pattern was formed was taken out and observed with an electron microscope, a line and space of 0.50 μm was resolved. The film thickness of the pattern was 1.15 μm as measured by a film thickness meter Alpha Step 200.

(Effect of the Invention) The resist composition of the present invention has sensitivity, resolution, residual film ratio,
Since it has excellent properties such as heat resistance and storage stability, it is particularly suitable for fine processing of 1 μm or less.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Noriyuki Sanpeira 1-1-2, Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa Pref. JP-A-63526 (JP, A) JP-A-60-134235 (JP, A) JP-A-3-179353 (JP, A)

Claims (1)

(57) [Claims] 1. A positive resist composition comprising an alkali-soluble phenol resin and a photosensitizer, wherein the photosensitizer comprises 90% or less of quinonediazide sulfone in all phenolic hydroxyl groups of the compound represented by the following general formula (I). A positive resist composition comprising an acid esterified compound. (A: alkylene group, substituted alkylene group, alkenylene group, substituted alkenylene group, arylene group or substituted arylene group R ^{1 to} R ⁸ : hydrogen, halogen, C _{1 to} C ₄ alkyl group, C _{1 to} C ₄
An alkoxy group, an alkenyl group or a hydroxyl group of C ₁ -C _4, may be the same or different)