JP2631744B2 - 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.

At present, a positive resist composition generally used in this field comprises a nopolak 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. .

(Objects 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, residual film ratio, heat resistance, and storage stability, especially 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) In a positive resist composition containing an alkali-soluble phenol resin and a photosensitizer, a quinonediazidesulfonic acid ester of a compound represented by the following general formula (I) is contained as the photosensitizer. A positive resist composition comprising:

R ^{1 to} R ⁵ : hydrogen, halogen, C _{1 to} C ₄ alkyl, alkenyl, alkoxy, hydroxyl, or However, at least one of R ⁴ or R ⁵ , And the and, -CH ₂ in the formula - relative, (3-
n) —OH are bonded to the ortho position and / or the para position, and the ortho position of the para position —OH is a hydrogen atom.

A; -S-, -O-, R ⁶ ; hydrogen, halogen, alkyl group or alkenyl group, R ⁷ , R ⁸ ; hydrogen, alkyl group or alkenyl group n = 0, 1 or 2 Examples of the alkali-soluble phenol resin used in the present invention include phenols and Examples include condensation reaction products with aldehydes, condensation reaction products of phenols with ketones, vinylphenol polymers, isopropenylphenol polymers, and hydrogenation reaction products 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.

Here, specific examples of the aldehyde used include formaldehyde, acetaldehyde, benzaldehyde,
Terephthalaldehyde and the like.

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

 These condensation reactions can be performed according to a conventional method.

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 of these phenolic resins can be carried out by any known method, and the phenolic resin is dissolved in an organic solvent, and hydrogen is introduced in the presence of a homogeneous or heterogeneous hydrogenation catalyst. Can be achieved by doing

These alkali-soluble phenol resins may be used alone or in combination of two or more.

The positive resist composition of the present invention, if necessary, in order to improve developability, storage stability, heat resistance, etc., for example, a copolymer of styrene and acrylic acid, methacrylic acid or maleic anhydride, A copolymer of an alkene and maleic anhydride, a vinyl alcohol polymer, a vinyl pyrrolidone polymer, rosin, shellac and the like can be added.

The addition amount 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 photosensitive agent used in the present invention is not particularly limited as long as it is a quinonediazidesulfonic acid ester of the compound represented by the general formula (I). 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. However, equation (9) is excluded.

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) and the like.

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, and a plasticizer.

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-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.
30 parts of a quinonediazide compound in which 90% or more of the -OH groups of the compound (13) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid are dissolved in 320 parts of ethyl cellosolve acetate and filtered through a 0.1 μm Teflon filter. Then, a resist solution was prepared.

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 0.45 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 13.56.
When etched at MHz, it was observed that only the portions without the pattern were etched.

Example 2 The resist solution of Example 1 was applied on a silicon wafer by a coater, and baked at 80 ° C. for 90 seconds to a thickness of 1.2 μm.
m of the resist film was formed. The wafer was exposed using a g-line stepper NSR-1505G6E and a test reticle. Next, this wafer is subjected to PEB (POST EXP
(OSURE BAKING), 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, to which formalin was added, and novolak obtained by condensation using an oxalic acid catalyst by a conventional method. 100 parts of resin, 85% or more of -OH group of compound (13)
A resist solution was prepared by dissolving 33 parts of a quinonediazide compound, which is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, in 300 parts of ethyl lactate and filtering through a 0.1 μm Teflon filter.

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 0.45 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 80% or more of the -OH groups of the compound (13) is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, is 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 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 0.45 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 (mole ratio: 7: 3), and 90% or more of the -OH group of the compound (26) was 1,2.
28 parts of a quinonediazide compound, which is an ester of naphthoquinonediazide-5-sulfonic acid, was dissolved in 310 parts of ethyl cellosolve acetate 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 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 0.45 μm 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.
Parts, a quinonediazide compound in which 85% or more of the -OH groups of the compound (26) is an ester of 1,2-naphthoquinonediazide-4-sulfonic acid is dissolved in 300 parts of diglyme and 0.1 µm
Was filtered through a Teflon filter to prepare a resist solution.

The resist solution was applied on a silicon wafer with 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
Exposure was performed using ALS WAFERSTEP 2142i (NA = 0.54, manufactured by GCA) 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 0.45 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) 100 parts, 30 parts of a quinonediazide compound in which 85% or more of the -OH groups of the compound (26) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid are dissolved in 300 parts of diglyme.
The solution was filtered through a 0.1 μm Teflon filter to prepare a resist solution.

The resist solution was applied on a silicon wafer with 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
Exposure was performed using ALS WAFERSTEP 2142i (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 0.45 μm was resolved. The film thickness of the pattern was 1.15 μm as measured by a film thickness meter Alpha Step 200.

Example 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.
28 parts of a quinonediazide compound in which 90% or more of the -OH groups of the compound (28) are 1,2-naphthoquinonediazide-5-sulfonic acid esters are dissolved in 320 parts of ethyl cellosolve acetate and filtered through a 0.1 μm Teflon filter. Then, a resist solution was prepared.

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 0.45 μm was resolved. The film thickness of the pattern was 1.15 μm as measured by a film thickness meter Alpha Step 200.

Example 9 Novolak resin 100 obtained by mixing m-cresol and p-cresol at a molar ratio of 6: 4, adding formalin thereto, and condensing by an ordinary method using an oxalic acid catalyst.
Of a quinonediazide compound in which 80% or more of the -OH groups of the compound (28) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid are dissolved in 300 parts of ethyl lactate to obtain a solution of 0.1 μm
Was filtered through a 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. Then, a 2.38% aqueous solution of tetramethylammonium hydroxide was developed 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 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 10 100 parts of a hydrogenation reaction product of a vinylphenol polymer (hydrogenation ratio: 35%) and 85% or more of -OH groups of compound (28)
A resist solution was prepared by dissolving 30 parts of a quinonediazide compound, which is an ester of 1,2-naphthoquinonediazide-4-sulfonic acid, in 300 parts of diglyme and filtering through a 0.1 μm Teflon filter.

The resist solution was applied on a silicon wafer by a coater and baked at 100 ° C. for 90 seconds to form a 1.00 μm thick resist film. This wafer was exposed using an excimer laser device C2926 (manufactured by Hamamatsu Photonics) containing krypton / fluorine and a test mask.
Next, an aqueous solution of tetramethylammonium hydroxide 23
Developed by paddle method at ℃ for 1 minute to obtain 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. When the film thickness of the pattern was measured by a film thickness meter Alpha Step 200, it was 0.95 μm.

Example 11 100 parts of a hydrogenation reaction product of a vinylphenol polymer (hydrogenation ratio: 30%), and 90% or more of the -OH group of compound (13)
A resist solution was prepared by dissolving 28 parts of a quinonediazide compound, which is an ester of 1,2-naphthoquinonediazide-4-sulfonic acid, in 300 parts of diglyme and filtering through a 0.1 μm Teflon filter.

The resist solution was applied on a silicon wafer by a coater and baked at 100 ° C. for 90 seconds to form a 1.00 μm thick resist film. The wafer was exposed using a far ultraviolet irradiation apparatus PLA-521FA (manufactured by Canon Inc.) and a test mask. Next, it was developed with a tetramethylammonium hydroxide aqueous 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 0.40 μm was resolved. The film thickness of the pattern was 0.92 μm when measured with 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.

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Claims (1)

(57) [Claims] 1. A positive resist composition containing an alkali-soluble phenol resin and a photosensitizer, characterized in that the photosensitizer contains a quinonediazidesulfonic acid ester of a compound represented by the following general formula (I). Positive resist composition. R ^{1 to} R ⁵ : hydrogen, halogen, C _{1 to} C ₄ alkyl, alkenyl, alkoxy, hydroxyl, or However, at least one of R ⁴ or R ⁵ , And the and, -CH ₂ in the formula - relative, (3-
n) —OH are bonded to the ortho position and / or the para position, and the ortho position of the para position —OH is a hydrogen atom. A; -S-, -O-, R ⁶ : hydrogen, halogen, alkyl group or alkenyl group, R ⁷ , R ⁸ ; hydrogen, alkyl group or alkenyl group n = 0, 1 or 2