JPH087434B2 - Positive resist composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a positive resist composition, and more specifically, a positive resist for microfabrication 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, which is then developed to form a negative or positive image. A semiconductor element is formed by a lithographic technique.

Conventionally, as a resist composition for forming a semiconductor element, a negative resist composed of cyclized polyisoprene and a bisdiazide compound has been known. However, since this negative resist is developed with an organic solvent, it has a large swelling and a limited resolution, so that it has a drawback that it cannot be applied to the production of highly integrated semiconductors. On the other hand, in contrast to this negative resist composition, the positive resist composition is considered to be sufficiently compatible with high integration of semiconductors because of its excellent resolution.

At present, the positive resist composition generally used in this field comprises a novolac resin and a quinonediazide compound.

However, the conventional positive resist compositions have not always obtained satisfactory results in various characteristics such as sensitivity, residual film rate, resolution, heat resistance, and storage stability, and improvement in performance is desired.

(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 have excellent properties such as sensitivity, residual film rate, resolution, heat resistance, and storage stability. It is to provide a positive resist composition suitable for fine processing.

(Means for Solving the Problems) The object of the present invention is to provide a positive resist composition containing an alkali-soluble phenolic resin and a photosensitizer, and the quinonediazide sulfone of a compound represented by the following general formula (I) as the photosensitizer. It is achieved by a positive resist composition containing an acid ester.

R _1-10 : H, halogen, hydroxyl group, C _{1 to} C ₃ alkyl group or alkenyl group, or C _{1 to} C ₃
And substituted or unsubstituted hydroxyalkyl groups, which may be the same or different.

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, vinylphenol-based polymers, isopropenylphenol-based polymers, Hydrogenation reaction products of these phenolic resins and the like can be mentioned.

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

Specific examples of aldehydes used here include formaldehyde, acetaldehyde, benzaldehyde, and terephthalaldehyde.

Specific examples of the ketones used here include acetone,
Methyl ethyl ketone, diethyl ketone, diphenyl ketone, etc. are mentioned.

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

The vinylphenol polymer is selected from vinylphenol homopolymers and copolymers of vinylphenol and copolymerizable components. Specific examples of the copolymerizable component include acrylic acid, methacrylic acid, styrene,
Examples thereof include maleic anhydride, maleic imide, vinyl acetate, acrylonitrile, and derivatives thereof.

The isopropenylphenol-based polymer is selected from isopropenylphenol homopolymers and copolymers with a component copolymerizable with isopropenylphenol. Specific examples of the copolymerizable component include acrylic acid,
Examples thereof include methacrylic acid, styrene, maleic anhydride, maleic imide, vinyl acetate, acrylonitrile, and derivatives thereof.

When using the hydrogenation reaction product of a phenol resin,
The reaction can be carried out by any known method, and can be achieved by dissolving the phenol resin in an organic solvent and introducing hydrogen in the presence of a homogeneous or heterogeneous hydrogenation catalyst.

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 of addition is 100 above alkali-soluble phenol resin
The amount is 0 to 50 parts by weight, preferably 5 to 20 parts by weight.

The photosensitizer used in the present invention is not particularly limited as long as it is a quinonediazide sulfonic acid ester of the compound represented by the general formula (I),
-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, sulfonic acid ester of other quinonediazide derivatives, etc. To be

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

In the photosensitizer used in the present invention, the ratio of esterification of the quinonediazide compound with respect to the phenol compound represented by the general formula (I) is not particularly limited, but is preferably 50 to 100 mol%. Particularly preferably 7
It is in the range of 0 to 95 mol%. When the esterification ratio is low, the pattern shape and resolution are deteriorated, and when the esterification ratio is high, the sensitivity is deteriorated, which is not preferable.

The amount of the photosensitizer used in the present invention with respect to the resin component is not particularly limited, but is preferably 5 to 50 parts by weight with respect to 100 parts by weight of the resin. Particularly preferably, 10-40
The range is parts by weight. If the compounding amount is small, a sufficient residual film ratio cannot be obtained, which leads to deterioration of resolution, and if the compounding amount is large, sensitivity,
It is not preferable because it causes deterioration of heat resistance.

The photosensitizer used in the present invention can be used alone or as a mixture with another kind of photosensitizer. The other type of photosensitizer to be mixed is not particularly limited, and any sulfonate of general quinonediazide can be used.
Specific examples include cresol, xylenol, resorcin, catechol, hydroquinone, pyrogallol, phloroglucinol, phloroglucide, 2,3,4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,3,4, 4'-tetrahydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone,
2,2 ', 3,4,4'-pentahydroxybenzophenone, 2,
2 ', 3,4,5'-pentahydroxybenzophenone, 2,3,
3 ', 4,5'-pentahydroxybenzophenone, 2,3,
3 ', 4,4', 5'-hexahydroxybenzophenone, 2,
3 ', 4,4', 5 ', 6-hexahydroxybenzophenone,
Methyl gallate, ethyl gallate, propyl gallate,
2,2-bis (4-hydroxyphenyl) propane, 2,2-
Of bis (2,4-dihydroxyphenyl) propane, 2,2-bis (2,3,4-trihydroxyphenyl) propane, cresol novolac resin, resorcin-acetone resin, pyrogallol-acetone resin, polyvinylphenol resin and vinylphenol Examples thereof include quinone diazide sulfonic acid esters such as copolymers.

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, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol are used. , Alcohols such as cyclohexanol, 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 butyrate, Ethyl butyrate, methyl lactate, esters such as ethyl lactate, cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, cellosolve esters such as butyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether,
Propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol such as propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol such as diethylene glycol methyl ethyl ether, Examples thereof include halogenated hydrocarbons such as trichloroethylene, aromatic hydrocarbons such as toluene and xylene, polar solvents such as dimethylacetamide, dimethylformamide, N-methylacetamide, and the like. These are 2 alone
You may mix and use 1 or more types.

The positive resist composition of the present invention may contain compatible additives such as dyes, surfactants, storage stabilizers, sensitizers, anti-striation agents, and plasticizers, if necessary. .

As the developer of the positive resist composition of the present invention, an aqueous solution of alkali is used, and specifically, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium silicate, and ammonia, ethylamine, propylamine, etc. Primary amines, secondary amines such as diethylamine and dipropylamine, tertiary amines such as trimethylamine and triethylamine, alcohol amines such as dimethylmethanolamine and triethanolamine,
Examples thereof include quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide and trimethylhydroxyethylammonium hydroxide.

Furthermore, if necessary, an appropriate amount of an aqueous solution organic solvent such as methanol, ethanol, propanol, or 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% in the examples are by weight unless otherwise specified.

Example 1 m-cresol, p-cresol and 3,5-xylenol were mixed at a molar ratio of 50:30:20, and formalin was added to the mixture, which was condensed by an ordinary method using an oxalic acid catalyst to give novolak. A resin was obtained. A compound (of the above formula) and this-
1,2-Naphthoquinonediazide 5-sulfonyl chloride corresponding to 75 mol% of OH groups was dissolved in dioxane, and triethylamine was added to this to effect esterification to obtain a photosensitizer.

100 parts of the above resin and 30 parts of the photosensitizer are dissolved in 350 parts of ethyl lactate to make 0.1 μm polytetrafluoroethylene (PTFE)
A resist solution was prepared by passing through a filter.

After coating the above resist solution on a silicon wafer with a coater, bake at 100 ° C for 90 seconds to give a thickness of 1.17μ.
m resist film was formed.

This wafer was exposed using a g-line stepper NSR1505G6E (manufactured by Nikon Corporation, NA = 0.54) and a test reticle. Then, it was developed with a 2.38% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 1 minute by a paddle method to form a positive pattern.

When this wafer was taken out and observed with an electron microscope, a 1: 1 line & space pattern of 0.65 μm was formed according to the design dimensions at an exposure dose of 350 msec.
The line and space of μm was resolved. Also, the exposure amount is 39
The line and space of 0.45 μm resolved at 0 m sec.
This pattern was vertical and had a good shape. The film thickness of the pattern was 1.14 μm.

Example 2 A compound (of the above formula) and 1,2-naphthoquinonediazide-5-sulfonyl chloride corresponding to 70 mol% of this —OH group were dissolved in dioxane, and triethylamine was added thereto to effect esterification. I got a photosensitizer.

100 parts of the resin used in Example 1 and 30 parts of the above photosensitizer were dissolved in 360 parts of ethyl lactate and passed through a 0.1 μm PTFE filter to obtain a resist solution.

The resist solution was patterned in the same manner as in Example 1. Observation with an electron microscope revealed that a 1: 1 line & space pattern of 0.65 μm was formed according to the design dimensions at an exposure dose of 360 msec, at which time a line & space of 0.5 μm was resolved. Also, the exposure amount is 400 m sec
The 0.45 μm line and space was resolved at. This pattern was vertical and had a good shape. The film thickness of the pattern was 1.14 μm.

Example 3 m-cresol and p-cresol were mixed at a molar ratio of 5: 5, to which formalin was added and condensed by an ordinary method using an oxalic acid catalyst to obtain a novolak resin. A compound (of the above formula) and corresponding to 90 mol% of this --OH group
1,2-naphthoquinonediazide-5-sulfonyl chloride was dissolved in dioxane, and triethylamine was added to this to effect esterification to obtain a photosensitizer.

100 parts of the above resin and 30 parts of the photosensitizer were dissolved in 350 parts of ethyl lactate and passed through a 0.1 μm PTFE filter to prepare a resist solution.

After coating the above resist solution on a silicon wafer, it was baked at 90 ° C. for 90 seconds to form a resist film having a thickness of 1.17 μm. This wafer is g-line stepper NSR1505G6E
Exposure was performed using a test reticle (manufactured by Nikon Corporation, NA = 0.54). Next, PEB the wafer at 110 ° C for 60 seconds.
After (POST EXPOSURE BAKING), it was developed with a 2.38% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 1 minute by a paddle method to form a positive pattern.

When the above wafer was taken out and observed with an electron microscope, a 1: 1 line & space pattern of 0.65 μm with an exposure dose of 400 m sec was formed according to the design dimensions.
The line and space of μm was resolved. Also, the exposure amount 43
The line and space of 0.40 μm resolved at 0 m sec.
This pattern was vertical and had a good shape.

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

Example 4 A compound (of the above formula) and 1,2-naphthoquinonediazide-5-sulfonyl chloride corresponding to 90 mol% of this -OH group were dissolved in dioxane, and triethylamine was added thereto to effect esterification. I got a photosensitizer.

100 parts of the resin used in Example 3 and 30 parts of the above-mentioned photosensitizer were dissolved in 360 parts of ethyl lactate and passed through a 0.1 μm PTFE filter to obtain a resist solution.

The resist solution was patterned in the same manner as in Example 3. Observation with an electron microscope revealed that a 1: 1 line & space pattern of 0.65 μm was formed according to the design dimension at an exposure dose of 430 msec, at which time a line & space of 0.45 μm was resolved. Also, the exposure amount is 480 m sec
The line and space of 0.40 μm were resolved. This pattern was vertical and had a good shape.

Example 5 A compound (of the above formula) and 1,2-naphthoquinonediazide-5-sulfonyl chloride corresponding to 85 mol% of this —OH group were dissolved in dioxane, and triethylamine was added thereto to effect esterification. I got the medicine.

100 parts of the resin used in Example 1 and 30 parts of the above photosensitizer were dissolved in 360 parts of ethyl lactate and passed through a 0.1 μm PTFE filter to obtain a resist solution.

The resist solution was patterned in the same manner as in Example 3. Observation with an electron microscope revealed that a 1: 1 line & space pattern of 0.65 μm was formed according to the design dimension at an exposure dose of 450 msec, at which time a line & space of 0.45 μm was resolved. Also, the exposure amount is 500 m sec
The line and space of 0.40 μm were resolved. This pattern was vertical and had a good shape.

Example 6 A novolak resin was obtained by mixing m-cresol and p-cresol at a molar ratio of 4: 6, adding formalin thereto, and condensing the mixture with an oxalic acid catalyst by a conventional method. A compound (of the above formula) and corresponding to 90 mol% of this --OH group
1,2-naphthoquinonediazide-5-sulfonyl chloride was dissolved in dioxane, and triethylamine was added to this to effect esterification to obtain a photosensitizer.

100 parts of the resin and 25 parts of the photosensitizer were dissolved in 360 parts of ethyl lactate and passed through a 0.1 μm PTFE filter to obtain a resist solution.

The resist solution was patterned in the same manner as in Example 3. Observation with an electron microscope revealed that a 1: 1 line & space pattern of 0.65 μm was formed according to the design dimension at an exposure dose of 360 msec, at which time a line & space of 0.45 μm was resolved. Also, the exposure amount is 410 m sec
The line and space of 0.40 μm were resolved. This pattern was vertical and had a good shape.

Example 7 A compound (of the above formula) and 1,2-naphthoquinonediazide-5-sulfonyl chloride corresponding to 95 mol% of this -OH group were dissolved in dioxane, and triethylamine was added thereto to effect esterification. I got a photosensitizer.

100 parts of the resin used in Example 6 and 20 parts of the above-mentioned photosensitizer were dissolved in 360 parts of ethyl lactate and passed through a 0.1 μm PTFE filter to obtain a resist solution.

The resist solution was patterned in the same manner as in Example 3. Observation with an electron microscope revealed that a 1: 1 line & space pattern of 0.65 μm was formed according to design dimensions at an exposure dose of 300 msec, at which time a line & space of 0.5 μm was resolved. Also, the exposure amount is 500 m sec
The 0.45 μm line and space was resolved at. This pattern was vertical and had a good shape.

Example 8 100 parts of the resin of Example 3 and 20 parts of the photosensitizer of Example 3 were dissolved in 350 parts of ethyl lactate and passed through a 0.1 μm PTFE filter to prepare a resist solution.

The above resist solution was coated on a silicone wafer with a coaster and baked at 90 ° C. for 90 seconds to form a resist film having a thickness of 1.2 μm. This wafer is an i-line stepper
Exposure was performed using ALS WAFERSTEP 2142i (manufactured by General Signal Company) and a test reticle. Next this wafer
After PEB (POST EXPOSURE BAKING) at 110 ℃ for 60 seconds, 2.
23% with 38% tetramethylammonium hydroxide aqueous solution
It was developed by a paddle method at 1 ° C. for 1 minute to form a positive pattern.

When this wafer was taken out and observed with an electron microscope, a 1: 1 line & space pattern of 0.70 μm was formed according to the design dimensions at an exposure dose of 340 msec.
The line and space of μm was resolved. Also, the exposure amount is 37
The line and space of 0.45 μm resolved at 0 m sec.
This pattern was vertical and had a good shape.

Example 9 100 parts of the resin of Example 3 and 20 parts of the photosensitizer of Example 4 were dissolved in 350 parts of ethyl lactate and filtered through a 0.1 μm PTFE filter to obtain a resist solution.

A pattern was formed from the resist solution in the same manner as in Example 8. Observation with an electron microscope revealed that a 0.70 μm 1: 1 line & space pattern was formed according to the design dimensions at an exposure of 360 msec, at which time a 0.5 μm line & space was resolved. Also, the exposure amount is 400 m sec
The 0.45 μm line and space was resolved at. This pattern was vertical and had a good shape.

Example 10 A compound (of the above formula) and 1,2-naphthoquinonediazide-4-sulfonyl chloride corresponding to 90 mol% of this -OH group are dissolved in dioxane, to which an aqueous sodium hydrogen carbonate solution is added to form an ester. To obtain a photosensitizer.

100 parts of the resin of Example 6 and 25 parts of the above photosensitizer were mixed with 3 parts of ethyl lactate.
It was dissolved in 50 parts and filtered through a 0.1 μm PTFE filter to obtain a resist solution.

The resist solution was patterned in the same manner as in Example 8. Observation with an electron microscope revealed that a 0.71 μm line and space pattern of 0.70 μm was formed according to the design dimensions at an exposure dose of 300 msec, at which time a 0.5 μm line and space was resolved. Also, the exposure amount is 340 m sec
The 0.45 μm line and space was resolved at.

Example 11 2,3,4,4'-Tetrahydroxybenzophenone and 1,2-naphthoquinonediazide-5-sulfonyl chloride corresponding to 95 mol% of this -OH group were dissolved in dioxane, and triethylamine was added thereto. In addition, esterification was performed to obtain a photosensitizer.

100 parts of the resin of Example 3, 20 parts of the photosensitizer of Example 3 and 10 parts of the photosensitizer were dissolved in 360 parts of ethyl lactate to give 0.1 micron.
The resist solution was obtained by passing through a PTFE filter.

The resist solution was patterned in the same manner as in Example 3. Observation with an electron microscope revealed that a 1: 1 line & space pattern of 0.65 μm was formed according to the design dimension at an exposure dose of 360 msec, at which time a line & space of 0.45 μm was resolved. Also, the exposure amount is 400 m sec
The line and space of 0.40 μm were resolved. This pattern was vertical and had a good shape.

Example 12 Phloroglucinol and 1,2-naphthoquinonediazide-5-sulfonyl chloride corresponding to 90 mol% of this —OH group were dissolved in dioxane, and triethylamine was added thereto to effect esterification. I got it.

100 parts of the resin of Example 3, 20 parts of the photosensitizer of Example 3 and 10 parts of the photosensitizer were dissolved in 360 parts of ethyl lactate to give 0.1 micron.
The resist solution was obtained by passing through a PTFE filter.

The resist solution was patterned in the same manner as in Example 3. Observation with an electron microscope revealed that a 1: 1 line & space pattern of 0.65 μm was formed according to the design dimension at an exposure dose of 330 msec, at which time a line & space of 0.45 μm was resolved. Also, the exposure amount is 380 m sec
The line and space of 0.40 μm were resolved. This pattern had a vertical shape.

Example 13 100 parts of a hydrogenation reaction product of a vinylphenol polymer (hydrogenation rate 35%) and 25 parts of the photosensitizer of Example 10 were dissolved in 320 parts of diglyme and passed through a 0.1 μm PTFE filter to obtain a resist solution. .

The resist solution was coated on a silicon wafer with a coater and baked at 100 ° C. for 90 seconds to form a resist film having a thickness of 1.0 μm. This wafer was exposed using a KrF excimer laser device C2926 (Hamamatsu Photonics KK) and a test mask. Next, it was developed with a 2.0% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 1 minute by a paddle method to obtain a positive pattern.

When the patterned wafer was taken out and observed with an electron microscope, a line & space pattern of 0.45 μm was resolved at an exposure dose of 220 mJ / cm ² .

(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, it is particularly suitable for fine processing of 1 μm or less.

Claims (1)

[Claims] 1. A positive resist composition containing an alkali-soluble phenol resin and a photosensitizer, wherein the photosensitizer contains a quinonediazide sulfonic acid ester of a compound represented by the following general formula (I). Type resist composition. R _1-10 : H, halogen, hydroxyl group, C _{1 to} C ₃ alkyl group or alkenyl group, or C _{1 to} C ₃
And substituted or unsubstituted hydroxyalkyl groups, which may be the same or different.