KR20120058191A - Positive photoresist composition having good coating uniformity - Google Patents

Abstract

PURPOSE: A positive photo-resist composition is provided to improve film uniformity and film speed and to improve working environment by reducing the generated amount of bad odor. CONSTITUTION: A positive photo-resist composition includes 10-25 weight% of alkali soluble novolak resin, 1-10 weight% of diazide-based compounds as a photo-resist compound, and 65-85 weight% of a solvent. The solvent includes 3-methoxy butyl acetate and diethylene glycol monophenylether at a weight ratio of 9:1 to 5:5. The novolak resin is cresol novolak resin. The diazide-based compounds are phenolic compounds with hydroxyl groups and the ester compounds of the diazide-based compounds.

Description

Positive photoresist composition excellent in coating property {POSITIVE PHOTORESIST COMPOSITION HAVING GOOD COATING UNIFORMITY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to positive photoresist compositions used in the manufacture of microcircuits, such as liquid crystal display circuits and semiconductor integrated circuits.

In order to form a fine circuit pattern, such as a liquid crystal display device circuit or a semiconductor integrated circuit, first, a photoresist composition is uniformly coated or coated on an insulating film or a conductive metal film formed on a substrate and coated in the presence of a mask having a predetermined shape. The resist composition is exposed and developed to form a pattern of the desired shape. The metal film or the insulating film is etched using the patterned photoresist film as a mask, and then the remaining photoresist film is removed to form a fine circuit on the substrate. Such photoresist compositions are classified into a negative type and a positive type according to the change in solubility of the exposed part. Currently, a positive type photoresist composition capable of forming a fine pattern is mainly used.

In the liquid crystal display device manufacturing process, the resist coating method uses a spin coating method when the size of the substrate is small. However, as the substrate becomes larger, the method of coating the resist is changing to a slit coating method. In the case of the slit coating method, since the centrifugal force by the conventional rotary coating method is not applied, it is required to use a solvent and a surfactant having excellent flatness for uniform coating properties.

Various solvents have been developed for improving the physical properties and operational stability of the above-mentioned resist composition, and examples thereof include ethylene glycol monoethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, and the like. However, the above solvents have a disadvantage in that they are harmful to the human body or cause a bad smell in the process, or make it difficult to uniformly coat the adhesion to the substrate.

Accordingly, Korean Patent No. 10-363273 discloses a technique of mixing and mixing propylene glycol methyl ether acetate and methyl methoxy propionate at a predetermined ratio in order to overcome the disadvantage. However, the resist composition of the patent also had a problem of poor coating performance when used in a large substrate.

The present invention has been made to solve the above problems, the present invention has a low amount of odor generation, excellent photosensitivity, residual film rate, development contrast, etc., in particular, coating film uniformity and stain characteristics on a large substrate It is an object to provide this excellent positive photoresist composition.

In order to achieve the above object, the present invention (a) alkali soluble novolak resin; (b) a diazide compound as the photosensitive compound; And (c) a solvent comprising 3-methoxybutyl acetate and diethylene glycol monophenyl ether in a weight ratio of 9: 1 to 5: 5.

Preferably the present invention (a) 10-25% by weight of alkali-soluble novolak resin; (b) 1 to 10% by weight of a diazide compound as the photosensitive compound; And (c) 65 to 85 wt% of a solvent comprising 3-methoxybutyl acetate and diethylene glycol monophenyl ether in a weight ratio of 9: 1 to 5: 5.

Since the positive photoresist composition of the present invention has excellent photosensitivity, residual film ratio, and film uniformity, it can be easily applied to actual industrial sites using large substrates, and the amount of odors is generated so that the working environment is changed well. You can.

Hereinafter, the present invention will be described in detail.

The photoresist composition of this invention contains (a) alkali-soluble novolak resin, (b) diazide type photosensitive compound, and (c) mixed solvent of 3-methoxybutyl acetate and diethylene glycol monophenyl ether.

The alkali-soluble novolak resin used in the photoresist composition of the present invention may be used without limitation as long as it is a novolak resin commonly used in the art. Preferably, the novolak resin may be obtained by addition-condensation reaction between a phenol compound and an aldehyde compound, and the addition-condensation reaction is carried out by a conventional method in the presence of an acid catalyst. Specifically the addition-condensation reaction is carried out in a suitable solvent or in bulk, the reaction temperature is usually 60-250 ° C. and the reaction time is usually 2-30 hours.

At this time, the phenolic compound is phenol, o-, m- and p-cresol, 2,5-xylenol, 3,5-xylenol, 3,4-xylenol, 2,3,5- Trimethylphenol, 4-t-butylphenol, 2-t-butylphenol, 3-t-butylphenol, 3-ethylphenol, 2-ethylphenol, 4-ethylphenol, 3-methyl-6-t-butylphenol, 4-methyl-2-t-butylphenol, 2-naphthol, 1,3-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, etc. are mentioned. In addition, the aldehyde compound is formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylaldehyde, α- and β-phenylpropyl aldehyde, o-, m- and p-hydroxybenzaldehyde, glutaraldehyde, glyc Oxal, o- and p-methylbenzaldehyde and the like. Examples of the acid catalyst include organic acids such as oxalic acid, formic acid, trichloroacetic acid, and p-toluenesulfonic acid; Inorganic acids such as hydrochloric acid, sulfuric acid, perchloric acid, phosphoric acid, and the like; And divalent metal salts such as zinc acetate, magnesium acetate, and the like.

The novolak resin produced by the addition-condensation reaction preferably has a weight average molecular weight of 2,000 to 50,000 in terms of polystyrene.

More preferably, as the novolak resin, cresol novolak resin may be used. For example, a polymer polymer synthesized by reacting formaldehyde with an aromatic alcohol such as phenol, meta and / or para cresol may be used.

In the present invention, the alkali-soluble novolak resin is preferably included in 10 to 25% by weight based on the total amount of the composition. If the novolak resin is included in less than 10% by weight may cause problems in the pattern formation, and when included in excess of 25% by weight, the sensitivity is slow, scum may occur, the appropriate sensitivity is slowed through May cause problems.

The photosensitive compound which can be used in the photoresist composition of the present invention can be used without limitation as long as it corresponds to a diazide compound. Preferably, an ester compound of a phenolic compound having a hydroxy group and a diazide compound is used as the photosensitive compound.

Phenolic compounds having the hydroxy group include 2,3,4,4'-tetrahydroxy benzophenone, trihydroxybenzophenone 2,3,4-trihydroxybenzophenone, 2,3,4,4-tetra Hydroxybenzophenone, 2,3,4,2,4-pentahydroxybenzophenone, tris 4-hydroxy phenylmethane, 1,3,5-tris 4-hydroxy a-dimethylbenzylbenzene, 1,1- Bis-4-hydroxyphenyl-1-4-1-4- hydroxyphenyl 1-methylethyl phenyl ethane, 2- (3,4-dihydroxyphenyl) -2- (4-hydroxyphenyl) propane and the like These can be mentioned, These can be used individually or in mixture of 2 or more types, respectively.

In addition, the diazide compounds include 1,2-naphthoquinone diazide, 2-diazo-1-naphthol-5-sulfonic acid, 2-diazo-1-naphthol-sulfonic acid, and 1,2-naphthoquinonedia Zide-5-sulfonic acid, 1,2-naphthoquinone diazide-4-sulfonic acid, 1,2-benzoquinone diazide-4-sulfonic acid, naphthoquinone-1,2-diazide-5-sulfonyl chloride, etc. For example. These can also be used individually or in mixture of 2 or more types, respectively. Preferably, a quinone diazide sulfonic acid compound or a quinone diazide sulfonyl halide compound is used as the diazide compound. At this time, the halide is preferably chloride.

Specific examples of the ester compound of the phenolic compound having a hydroxy group and the quinonediazide sulfonic acid compound include a phenolic polyhydroxy compound having at least three hydroxyl groups, and naphthoquinone-1,2-diazide-5-sulfonyl Preference is given to ester compounds of chloride, 1,2-naphthoquinonediazide-5-sulfonic acid, 1,2-naphthoquinonediazide-4-sulfonic acid or 1,2-benzoquinonediazide-4-sulfonic acid.

The ester compound may be obtained by reacting a phenolic compound having a hydroxy group with a diazide compound, preferably quinonediazidesulfonyl halide, in the presence of a base such as triethylamine in a solvent such as toluene or heptanol. have. After completion of the reaction, suitable post-treatment may be performed to separate the desired quinonediazide sulfonic acid ester. However, it is not necessarily limited thereto.

In the present invention, the photosensitive compound, that is, the diazide compound, is preferably included in an amount of 1 to 10% by weight based on the total amount of the composition. If the diazide compound is included in less than 1% by weight, the pattern may not be formed and a problem may occur in that the resist is mostly dissolved. If the diazide compound is included in excess of 10% by weight, there is a problem in that scum and the like may exist between the patterns. .

The solvent used in the photoresist composition of the present invention includes a mixture of 3-methoxybutyl acetate and diethylene glycol monophenyl ether in a weight ratio of 9: 1 to 5: 5. If the mixing weight ratio of 3-methoxybutyl acetate and diethylene glycol monophenyl ether is out of the range of 9: 1 to 5: 5, the coating performance of the resist may be poor, and there may be a problem in storage safety. have.

More preferably, the solvent includes a mixture of 3-methoxybutyl acetate and diethylene glycol monophenyl ether in a weight ratio of 8: 2 to 6: 4, and such solvents may further be used in terms of residual film ratio and film uniformity. Excellent effect.

In the present invention, the solvent is included in the remaining amount relative to the total amount of the composition, specifically, it is preferably included in 65 to 85% by weight. When the solvent is contained in less than 65% by weight, the viscosity is increased, the film thickness is excessively increased and the sensitivity is lowered. When the solvent is contained in excess of 85% by weight, the viscosity of the composition is lowered, resulting in a thinner film and a worse residual film ratio. There is a problem.

In some cases, in addition to the solvents described above, one or more other solvents commonly used in the art may be further included.

In addition, the photoresist composition of the present invention is one or two or more other additives commonly used in the art, for example, additives such as colorants, dyes, anti-scratching agents, plasticizers, adhesion promoters, speed promoters, surfactants, etc. It may include. By further including such an additive, it is possible to improve the performance according to the characteristics of the individual process when coating the substrate.

The photoresist composition of the present invention configured as described above may be applied to a substrate by a conventional method including dipping, spraying, rotating and spin coating, slit coating, and the like. For example, in the case of spin coating, a coating having a desired thickness can be formed by appropriately changing the solids content of the photoresist solution according to the type and method of the spinning apparatus. The substrate may include silicon, aluminum, silicon dioxide, doped silicon dioxide, silicon nitride, tantalum, copper, polysilicon, ceramics, aluminum / copper mixtures, and various polymerizable resins. However, it is not necessarily limited thereto.

The photoresist composition coated on the substrate by the method described above is heated to a temperature of 20 ° C to 150 ° C to perform a soft bake process. This treatment is carried out to evaporate the solvent without pyrolyzing the solid component in the photoresist composition. In general, it is desirable to minimize the concentration of the solvent through a soft bake process, so the treatment is performed until most of the solvent has evaporated and a thin coating of the photoresist composition remains on the substrate.

Next, a pattern having a desired shape is formed by exposing the substrate on which the photoresist film is formed to light, particularly ultraviolet light, using a suitable mask or template.

The substrate thus exposed is sufficiently immersed in an alkaline developing aqueous solution, and then left until all or almost all of the photoresist film in the portion exposed to light is dissolved. Suitable developing aqueous solutions include aqueous solutions containing alkali hydroxide, ammonium hydroxide or tetramethylammonium hydroxide (TMAH) and the like. The exposed part is removed and removed from the developer, and then heat treated again to perform a hard bake process to enhance adhesion and chemical resistance of the photoresist film. Such heat treatment is preferably carried out at a temperature below the softening point of the photoresist film, more preferably at a temperature of about 100 to 150 ℃.

The developed substrate is treated with a corrosion solution or a gas plasma to treat the exposed substrate. At this time, the unexposed portion of the substrate is protected by the photoresist film. After the substrate is treated in this manner, a photoresist film is removed with an appropriate stripper to form a fine circuit pattern on the substrate.

Hereinafter, the present invention will be described in more detail with reference to Examples and Test Examples. However, the following examples are illustrated to illustrate the present invention in detail and do not limit the scope of the present invention.

Examples 1-5 and Comparative Examples 1-3: Preparation of Positive Photoresist Composition

The components shown in Table 1 below were mixed according to the indicated contents to prepare the positive photoresist compositions of Examples 1 to 5 and Comparative Examples 1 to 3.

Test Example: Evaluation of Characteristics of Positive Photoresist Composition

The photoresist compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were added dropwise onto a 4 inch bare glass, respectively, and rotated at a constant rotational speed. A film film was formed. After mounting a mask having a predetermined shape on the film film, and irradiated with ultraviolet rays, and then immersed in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds to remove the portion exposed to ultraviolet rays to remove the photoresist pattern Formed. The following characteristics were evaluated and the results are shown in Table 1.

end. Speed

Effective sensitivity: The exposure amount when the cross section of a 5.0 micrometer line-and-space pattern is 1: 1.

After baking at 110 ° C., exposure and development were carried out and measurement was performed.

I. Residual rate

After baking at 110 ° C., the film was developed in a 2.38% by weight aqueous solution for 60 seconds without exposure, and the film thicknesses before and after the development were compared.

Residual film ratio = (film thickness after development / film thickness before development)

[97% or more: ◎, 94-97%: ○, 90-93%: △, 90% or less: X]

All. Film thickness uniformity

The photoresist was coated on a glass substrate having a size of 370 × 470 mm, the baking process was performed, and the film thickness of the coated resist was measured by about 30 points to evaluate the film uniformity.

Film uniformity = (maximum value-minimum value) / (2 X average value)

Less than 1%: ◎, 1-2%: ○, 3-5%: △, 5% or more: X]

division Suzy Photosensitizer Solvent Speed
(msec) Residual rate Membrane uniformity Example 1 18.49
(A / B = 60/40) 5.31
(C / D = 50/50) 76.2
(MBA / PhDG = 90/10) 39.7 ○ ○ Example 2 18.49
(A / B = 60/40) 5.31
(C / D = 50/50) 76.2
(MBA / PhDG = 80/20) 40.0 ◎ ◎ Example 3 18.49
(A / B = 60/40) 5.31
(C / D = 50/50) 76.2
(MBA / PhDG = 70/30) 40.0 ◎ ◎ Example 4 18.49
(A / B = 60/40) 5.31
(C / D = 50/50) 76.2
(MBA / PhDG = 60/40) 40.0 ◎ ◎ Example 5 18.49
(A / B = 60/40) 5.31
(C / D = 50/50) 76.2
(MBA / PhDG = 50/50) 39.8 ○ ○ Comparative Example 1 18.49
(A / B = 60/40) 5.31
(C / D = 50/50) 76.2
(MBA / PhDG = 40/60) 39.6 △ ○ Comparative Example 2 18.49
(A / B = 60/40) 5.31
(C / D = 50/50) 76.2
(MBA / PhDG = 100/0) 38.0 △ △ Comparative Example 3 18.49
(A / B = 60/40) 5.31
(C / D = 50/50) 76.2
(MBA / PhDG = 95/5) 39.7 ○ △

A: Cresol novolak resin obtained by condensation reaction of oxalic acid and formaldehyde to a mixture of 36 mol% of m-cresol and 64 mol% of p-cresol

B: Cresol novolak resin obtained by condensation reaction of oxalic acid and formaldehyde to a mixture of 57 mol% of m-cresol and 43 mol% of p-cresol

C: 1 mole of 2,3,4,4'-tetrahydroxybenzophenone and 2.3 moles of naphthoquinone-1,2-diazide-5-sulfonyl chloride

D: 1 mole of 2,3,4,4'-tetrahydroxybenzophenone and 1.5 moles of naphthoquinone-1,2-diazide-5-sulfonyl chloride

MBA: 3-methoxybutyl acetate

PhDG: diethylene glycol monophenyl ether

From Table 1, the composition of the Example which mixes 3-methoxy butyl acetate and diethylene glycol monophenyl ether in the weight ratio of 9: 1-5: 5, and has the photosensitivity, residual film rate, and film | membrane than the composition of the comparative example which are not It can be seen that the results are excellent in all aspects of uniformity.

Claims (7)

Alkali soluble novolak resins;
Diazide compounds as photosensitive compounds; And
Solvent containing 3-methoxybutyl acetate and diethylene glycol monophenyl ether in a weight ratio of 9: 1 to 5: 5
Positive photoresist composition comprising a.
The method according to claim 1,
Regarding the total weight of the composition,
10-25 weight% of alkali-soluble novolak resins;
1-10 weight% of diazide compounds as a photosensitive compound; And
65-85 weight% of solvents containing 3-methoxybutyl acetate and diethylene glycol monophenyl ether in the weight ratio of 9: 1-5: 5
Positive photoresist composition comprising a.
The method according to claim 1,
The solvent is a positive photoresist composition comprising 3-methoxybutyl acetate and diethylene glycol monophenyl ether in a weight ratio of 8: 2 to 6: 4.
The method according to claim 1,
The novolac resin is a positive photoresist composition, characterized in that the cresol novolac resin.
The method according to claim 1,
The diazide compound is a positive photoresist composition, characterized in that the ester compound of the phenolic compound having a hydroxy group and the diazide compound.
The method according to claim 5,
The phenolic compound having a hydroxy group is 2,3,4,4'-tetrahydroxy benzophenone, trihydroxy benzophenone 2,3,4-trihydroxybenzophenone, 2,3,4,4-tetrahydrate Hydroxybenzophenone, 2,3,4,2,4-pentahydroxybenzophenone, tris 4-hydroxy phenyl methane, 1,3,5-tris 4-hydroxy a-dimethylbenzylbenzene, 1,1-bis 4-hydroxyphenyl-1-4-1-4- hydroxyphenyl consisting of 1-methylethyl phenyl ethane and 2- (3,4-dihydroxyphenyl) -2- (4-hydroxyphenyl) propane 1 or 2 or more types selected from the group,
The diazide compound may be 1,2-naphthoquinone diazide, 2-diazo-1-naphthol-5-sulfonic acid, 2-diazo-1-naphthol-sulfonic acid, 1,2-naphthoquinone diazide- Group consisting of 5-sulfonic acid, 1,2-naphthoquinonediazide-4-sulfonic acid, 1,2-benzoquinonediazide-4-sulfonic acid and naphthoquinone-1,2-diazide-5-sulfonylchloride Positive photoresist composition, characterized in that one or two or more selected from.
The method according to claim 1,
The composition is a positive photoresist composition further comprises one or two or more additives selected from the group consisting of colorants, dyes, anti-scratches, plasticizers, adhesion promoters, speed promoters and surfactants.