JP2709508B2 - 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 drawback that it cannot cope with the manufacture of a highly integrated semiconductor because the swelling is large and the resolution is limited. 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. .

(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) An object of the present invention is to provide a positive resist composition containing an alkali-soluble phenol resin and a photosensitive agent, wherein the photosensitive agent is a quinonediazide sulfone of a compound represented by the following general formula (I). This is achieved by a positive resist composition comprising an acid ester.

R ¹ ~R ^6; H, halogen, alkyl of C ₁ -C _4, an alkenyl group, or a hydroxyl group R ^7, R ^8; H, alkyl halogen or ^{_{C 1 ~C 4 R 9, R}} 14; C 1 ~ Examples of the alkali-soluble phenolic resin used in the alkyl group present invention C _6, for example, condensation products of phenols and aldehydes, condensation reaction products of a phenol and a ketone, vinylphenol polymers, isopropenyl Examples include phenolic polymers and hydrogenation products of these phenolic resins.

Specific examples of phenols used here include phenol, cresol, xylenol, ethylphenol,
Monohydric phenols such as propylphenol, butylphenol, and phenylphenol; polyhydric phenols such as resorcinol, pyrocatechol, hydroquinone, bisphenol A, and pyrogallol.

Specific examples of the aldehyde used here include formaldehyde, acetaldehyde, benzaldehyde, terephthalaldehyde and the like.

Specific examples of ketones used here include acetone,
Examples thereof include methyl ethyl ketone, diethyl ketone, and diphenyl ketone.

 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 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 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.

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, pattern formation becomes impossible, and if it exceeds 100 parts by weight, development residue tends to occur.

The positive resist composition of the present invention is used by dissolving in a solvent. Examples of the solvent include acetone, methyl ethyl ketone, cyclohexane, cyclopentanone, ketones such as cyclohexanol, n-propyl alcohol, and iso.
-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 formate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl acetate, ethyl acetate, methyl lactate, esters such as ethyl lactate, cellosolve acetate, Cellosolve esters such as methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate and butyl cellosolve acetate; propylene glycols such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and propylene glycol monobutyl ether , Diethylene glycol monomethyl ether, diethylene glycol Over monoethyl ether, diethylene glycol such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, halogenated hydrocarbons such as trichlorethylene, toluene, aromatic hydrocarbons such as xylene, dimethylacetamide,
And polar solvents such as 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, 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 Primary amines, diethylamine, secondary amines such as dipropylamine, trimethylamine, tertiary amines such as triethylamine, diethylethanolamine, alcoholamines such as triethanolamine,
And quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, and trimethylhydroxyethylammonium hydroxide.

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 aqueous alkali 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 80% or more of the -OH groups of the compound (9) is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid was dissolved in 320 parts of ethyl cellosolve acetate, and the solution was filtered through a 0.1 μm Teflon filter. Then, a resist solution was prepared.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.17 μm.
Was formed. The wafer was exposed using a g-line stepper 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
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 80 ° C. for 90 seconds to 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
(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 observed 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 (9)
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 passing through a 0.1 μm Teflon filter.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.17 μm.
Was formed. The wafer was exposed using a g-line stepper 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 group of the compound (9) is 1,2-naphthoquinonediazide-5-sulfonic acid ester, was treated with ethyl cellosolve acetate 32.
It was dissolved in 0 parts and passed through a 0.1 μm Teflon filter to prepare a resist solution.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.17 μm.
Was formed. The wafer was exposed using a g-line stepper 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 80% or more of the -OH group of the compound (9) was 1,2.
28 parts of a quinonediazide compound, which is a naphthoquinonediazide-5-sulfonic acid ester, was dissolved in 310 parts of ethyl cellosolve acetate and passed through a 0.1 μm Teflon filter to prepare a resist solution.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.17 μm.
Was formed. The wafer was exposed using a g-line stepper 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 0.45 μm line & space was resolved. Measure the film thickness of the pattern
It was 1.10 μm when measured at 0.

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 (9) are esters of 1,2-naphthoquinonediazide-4-sulfonic acid are dissolved in 300 parts of diglyme, and 0.1 μm
Was passed through a Teflon filter to prepare a resist solution.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.20 μm.
Was formed. This wafer was exposed using an i-line stepper ALS WAFERSTEP2142i (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) Dissolve 100 parts, 30 parts of a quinonediazide compound in which 60% or more of the -OH groups of the compound (9) are 1,2-naphthoquinonediazide-5-sulfonic acid ester in 300 parts of diglyme and 0.1
The solution was passed through a μm Teflon filter to prepare a resist solution.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.20 μm.
Was formed. The wafer was exposed using an i-line stepper ALS WAFERSTEP2142i (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 70% or more of the -OH groups of the compound (12) is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid was added to ethyl cellosolve acetate 32.
It was dissolved in 0 parts and passed through a 0.1 μm Teflon filter to prepare a resist solution.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.17 μm.
Was formed. The wafer was exposed using a g-line stepper 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 m-cresol 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.
And 20 parts of a quinonediazide compound in which 60% or more of the -OH groups of the compound (14) are esters of 1,2-naphthoquinonediazide-5-sulfonic acid are dissolved in 300 parts of ethyl lactate to give 0.1 μm.
Was passed through a Teflon filter to prepare a resist solution.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.17 μm.
Was formed. The wafer was exposed using a g-line stepper 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 10 100 parts of a hydrogenation reaction product of a vinylphenol polymer (hydrogenation ratio: 35%), and 85% or more of -OH groups of compound (9)
30 parts of a quinonediazide compound, which is 1,2-naphthoquinonediazide-4-sulfonic acid ester, was dissolved in 300 parts of diglyme and passed through a 0.1 μm Teflon filter to prepare a resist solution.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.00 μm.
Was formed. Krypton /
Exposure was performed using an excimer laser device C2926 (manufactured by Hamamatsu Photonics) containing fluorine 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 0.45 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 (hydrogenation rate: 30%) of a vinylphenol polymer, and 90% or more of -OH groups of compound (9)
28 parts of a quinonediazide compound, which is 1,2-naphthoquinonediazide-4-sulfonic acid ester, was dissolved in 300 parts of diglyme and passed through a 0.1 μm Teflon filter to prepare a resist solution.

After applying the above resist solution on a silicone wafer with a coater, it was baked at 100 ° C. for 90 seconds to a thickness of 1.00 μm.
Was formed. This wafer was exposed using an ultraviolet irradiation apparatus PLA-521FA (manufactured by Canon Inc.) 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.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-57-63526 (JP, A)

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 ~R ^6; H, halogen, alkyl of C ₁ -C _4, an alkenyl group or a hydroxyl group R ^7, R ^8; H, alkyl group R ⁹ halogen or ^{_{C 1 ~C 4 ~R 14; C}} 1 ~ C ₆ alkyl group