JPH06194826A - Positive resist composition and production of color filter using the composition - Google Patents

Abstract

(57) [Summary] [Object] To provide a positive resist composition excellent in various performances such as resolution and heat resistance, and a method for producing a color filter excellent in various performances such as spectral characteristics. A positive resist composition comprising a resin curable by heat or an acid, a quinonediazide compound, a cross-linking agent and a pigment, and after coating the positive resist composition on a substrate, exposing through a mask, A method for producing a color filter, which comprises developing and removing an exposed part to form a positive colored pattern, and then exposing and curing the entire colored pattern which is an unexposed part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist composition used for color filters and a method for producing color filters using the same.

[0002]

2. Description of the Related Art Color filters, particularly color filters for solid-state image pickup devices such as charge-coupled devices (CCD) or liquid crystal display devices (LCD), have three primary color elements (red, green, blue) or three complementary color elements on a transparent or opaque substrate. A method of forming a pattern of (yellow, magenta, cyan), first forming a pattern with a photoresist and then dyeing it, or forming a pattern with a photoresist to which a coloring material such as a dye or pigment is added. It is manufactured using. However, the former method has problems such as complexity of the dyeing process and difficulty of process control.
On the other hand, as the latter method, for example, JP-A-1-152449,
JP-A-1-254918, JP-A-4-153657 and JP-A-4-16
A method using a photoresist or the like in which a pigment is dispersed, as described in Japanese Patent No. 3552, is proposed. This method is not suitable for manufacturing a CCD color filter that requires high resolution because the photoresist is a negative type. Furthermore, the method using a positive photoresist composition containing a novolac resin, a photo-modification dissolution inhibitor and a pigment as described in JP-A-4-175754 requires high temperature / long time heating after pattern formation. Therefore, there are problems such as deformation of the pattern shape and discoloration of the color filter due to the heat resistance of the novolac resin.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and a positive resist composition excellent in various performances such as resolution and heat resistance, and the process control using the same is easy. And a method of manufacturing a color filter having excellent various characteristics such as spectral characteristics.

[0004]

The present invention relates to a positive resist composition containing a heat-curable resin, a quinonediazide compound, a crosslinking agent and a pigment; an acid-curable resin, a quinonediazide compound, and a photoacid generator. A positive resist composition containing an agent, a cross-linking agent, and a pigment; and, after coating them on a substrate, exposing through a mask to develop and remove the exposed portion to form a positive colored pattern, It is a method for producing a color filter, which comprises exposing the above-mentioned colored pattern, which is an unexposed portion, to the entire surface and curing it.

As the resin which can be cured by heat or acid,
For example, a resin having a phenolic hydroxyl group or a carboxyl group, or J. Photopolym. Sci. Technol. Vol.
3, No. 3 (1990), pages 235-247, copolymers containing hydroxystyrene structures, i.e., p-
Examples thereof include a copolymer of hydroxystyrene and p-acetoxymethylstyrene. Examples of the resin having a carboxyl group include a copolymer of polymethacrylate and maleic anhydride. Examples of the resin having a phenolic hydroxyl group include an alkali-soluble phenol resin or novolac resin.
Examples of the novolac resin include those obtained by condensing phenols and aldehydes in the presence of an acid catalyst. Examples of phenols include phenol,
Cresol (m-cresol, p-cresol, etc.), ethylphenol, 2-t-butyl-5-methyl-phenol, butylphenol, xylenol, phenylphenol, catechol, resorcinol, pyrogallol,
Examples thereof include naphthol, bisphenol C, bisphenol A and the like. These phenols may be used alone or in combination of two or more. Examples of aldehydes include formaldehyde, paraformaldehyde,
Aliphatic or aromatic aldehydes such as acetaldehyde, propionaldehyde or benzaldehyde may be mentioned. A resin that can be cured by heat or acid, such as a resin having a phenolic hydroxyl group, may be adjusted in its molecular weight distribution by means such as fractionation, if necessary. Further, phenols such as bisphenol A or bisphenol C may be added to the resin which can be cured by heat or acid.

Examples of the cross-linking agent include the following formula-(CH ₂ ) _s OR (wherein R represents a hydrogen atom or a lower alkyl group, s
Represents an integer of 1 to 4. And a melamine having a group represented by the formula (1). As the compound having a group represented by the above formula, for example, the following formula

[0007]

[Chemical 1]

[In the formula, Z represents —NR ₁ R ₂ or a phenyl group. R _{1 to} R ₆ are each a hydrogen atom, — (CH ₂ ) _s OH, provided that at least one of them represents — (CH ₂ ) _s OH or — (CH ₂ ) _s OR _7.
Or - it represents a (CH _{2) s} OR _7. R ₇ represents a lower alkyl group. s represents an integer of 1 to 4. ] The compound shown by the following, or the following formula

[0009]

[Chemical 2]

[0010]

[Chemical 3]

Examples thereof include compounds represented by The lower alkyl group represented by R and R ₇ includes a methyl, ethyl, n-propyl or n-butyl group, and the preferred alkyl group includes a methyl or ethyl group. Each of the compounds represented by formulas (i) to (ii) can be produced by condensing p-cresol or t-butylphenol with formaldehyde under basic conditions. Further, the compounds represented by the formulas (iii) to (vi) are disclosed in JP-A-1-
It is a known compound described in Japanese Patent No. 293339. Formula- (C
Preferred compounds having a group represented by H ₂ ) _s OR include, for example, hexamethoxymethylolated melamine,
Hexamethoxyethylol melamine, hexamethoxypropyrolated melamine and the like can be mentioned.

The photoacid generator is not particularly limited as long as it can generate an acid directly or indirectly by light. For example, a trihalomethyltriazine-based compound described in JP-A-4-163552, disulfone compounds described in 1-57777 JP, the _{formula, R 8 -SO 2 -SO 2 -R} 9 -SO 2 -SO 2 -R 10 ( wherein, R ₈ and R ₁₀ are each independently A compound represented by optionally substituted aryl, aralkyl, alkyl, cycloalkyl or heterocyclic group, and R ₉ represents optionally substituted aryl), JP-A-1-2933.
No. 39, a photoacid generator containing a sulfonic acid ester group, represented by the following formula CF ₃ —SO ₂ O— (CH ₂ ) _n —Y (wherein Y represents an aryl group which may be substituted). n is 0
Or represents 1. ), A compound represented by the formula: CF ₃ —SO ₂ O— [C (Y ₁ ) (Y ₂ )] _m —C
(O) -Y ₃ (wherein, Y ₁ and Y ₂ are each independently optionally substituted by alkyl, alkoxy or aryl group, Y ₃
Is an optionally substituted aryl group, and m is 1 or 2
Are respectively represented. ), A compound represented by the formula: CF ₃ —SO ₂ O—N (Y ₄ ) —C (O) —Y ₅ (wherein Y ₄ represents an optionally substituted alkyl group, and
₅ represents an aryl group which may be substituted, respectively. ), A compound represented by the formula: CF ₃ —SO ₂ O—N═C (Y ₆ ) (Y ₇ ) (wherein Y ₆ represents a hydrogen atom or an optionally substituted alkyl or aryl group, Y ₇ Each represents an optionally substituted aryl group), a compound represented by the following formula:

[0013]

[Chemical 4]

Examples include onium salts represented by:

Examples of the quinonediazide compound include o
-Naphthoquinone diazide-5-sulfonic acid ester or sulfonic acid amide, or o-naphthoquinone diazide-
4-sulfonic acid ester, sulfonic acid amide, etc. are mentioned. These esters or amides are represented by the general formula (I) in JP-A-2-84650 and JP-A-3-49437.
It can be produced by a known method using the phenol compound described in 1.

The pigment is preferably an organic pigment such as azo, phthalocyanine, indigo, anthraquinone, dioxazine, quinacridone, isoindolinone, phthalone, methine, azomethine, metal complex or condensed polycyclic ring. Pigments such as CI Pigment Color described in the color index of the system. Examples of the solvent include methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol dimethyl ether, ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether, N, N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, cyclohexanone. , Ethyl acetate, n-butyl acetate,
Examples include propylene glycol monoethyl ether acetate, methyl lactate, ethyl lactate, ethyl pyruvate, dimethylformamide and the like. These solvents alone
Alternatively, they may be used in combination of two or more.

The heat-curable or acid-curable resin and the cross-linking agent are usually dissolved in a solvent at a proportion of about 2 to 50 and 2 to 30% by weight, respectively. The amounts of the quinonediazide compound, the photoacid generator and the pigment to be used are usually added in proportions of about 2 to 30, 2 to 30 and 2 to 50% by weight, respectively, with respect to the solution of the resin and the crosslinking agent. In addition, various additives commonly used in the art, such as a smoothing agent for imparting uniform coating properties or a dispersant for dispersing a pigment, can be added to the positive resist composition. .

The positive resist is one in which the exposed portion is removed and the unexposed portion remains as a positive colored pattern by utilizing the difference in solubility in an alkali developing solution due to exposure. That is, the quinonediazide compound is decomposed by exposure and becomes soluble in the alkali developing solution, while the unexposed portion acts to suppress the dissolution of the resin in the alkali developing solution. When the unexposed area is entirely exposed, the remaining quinonediazide compound is decomposed. On the other hand, when the photoacid generator is contained, it has an action of generating an acid to cure the positive type colored pattern. . For the exposure, for example, ultraviolet rays such as a mercury lamp, deep ultraviolet rays, electron beams or X-rays are used.

1 to 4 show one embodiment of the method of the present invention.
After applying a composition containing an acid-curable resin, a quinonediazide compound, a photoacid generator, a crosslinking agent, a pigment and a solvent to a substrate, the solvent is evaporated (see FIG. 1). The quinonediazide compound and the photo-acid generator in the exposed area are decomposed by exposure through a mask (see FIG. 2). After development, a positive type colored pattern of the unexposed area is obtained (see FIG. 3). The positive type colored pattern of the unexposed portion is entirely exposed to cure (see FIG. 4). The method of the present invention in which the entire surface is exposed to cure the pattern enhances the solvent resistance of the color filter.

[0020]

EXAMPLES Next, the present invention will be described more specifically by way of examples. In the examples, "part" means "part by weight". The common conditions in the following examples are as follows. A positive resist containing a quinonediazide compound, a pigment, a resin curable by heat or an acid, a cross-linking agent, a photo-acid generator (not necessary when cured by heat) and a solvent on a silicon wafer or a quartz wafer when manufacturing a color filter. After spin-coating the composition and evaporating the solvent by heating, the composition was exposed to light through a mask to decompose the quinonediazide compound. Then, after development, the entire surface was exposed to obtain a color filter. Exposure is made by Hitachi Ltd. i-line exposure stepper
It was performed by HITACHI LD-5010-i (NA = 0.40). As the developing solution, SOPD manufactured by Sumitomo Chemical Co., Ltd. was used.

Reference Example 1 20 parts of CIPigment Red 177 and CIPigment Yellow 83 mixture (75/25), 5 parts of sorbitan-based dispersant and 75 parts of ethyl cellosolve acetate were pre-kneaded, and then a red pigment dispersion was prepared by a bead mill method. did. Reference Example 2 CIPigment Red 177 and CIPigment Yellow 83 Instead of the mixture, CIPigment Green 7 and CIPigment Yellow
A green pigment dispersion liquid was prepared in the same manner as in Reference Example 1 except that the 83 mixture (90/10) was used. Reference Example 3 CIPigment Blue 15 and CIPigment Violet instead of CIPigment Red 177 and CIPigment Yellow 83 mixture
A blue pigment dispersion liquid was prepared in the same manner as in Reference Example 1 except that the 23 mixture (95/5) was used.

Example 1 3.4 parts of cresol novolac resin (polystyrene-equivalent weight average molecular weight 4300) obtained from a mixture of m-cresol / p-cresol / formaldehyde (reaction molar ratio = 5/5 / 7.5).

[0023]

[Chemical 5]

O-naphthoquinonediazide-5-sulfonic acid ester prepared by using a phenolic compound represented by the formula (on average, two hydroxyl groups are esterified) 1.8
Parts, hexamethoxymethylolated melamine 0.8 parts, ethyl cellosolve acetate 7 parts and 6 parts of the pigment dispersion obtained in Reference Example 1 were mixed and then pressure-filtered using a membrane filter to obtain a red positive resist composition. .

Example 2 A green positive resist composition was obtained in the same manner as in Example 1 except that the pigment dispersion liquid obtained in Reference Example 2 was used in place of the pigment dispersion liquid obtained in Reference Example 1.

Example 3 A blue positive resist composition was obtained in the same manner as in Example 1 except that the pigment dispersion liquid obtained in Reference Example 3 was used in place of the pigment dispersion liquid obtained in Reference Example 1.

Example 4 A silicon wafer was spin-coated with the red positive resist composition obtained in Example 1, and after exposure, an alkaline developer SOPD was used.
To obtain a colored pattern having a resolution of 5 μm. This colored pattern was exposed on the entire surface and then heat-cured at 150 ° C. for 10 minutes to obtain a red color filter. This color filter had sharp edges and did not show pattern collapse even when heated at 200 ° C. for 20 minutes.

Example 5 A green color filter was obtained in the same manner as in Example 1 except that the green positive resist composition obtained in Example 2 was used instead of the red positive resist composition obtained in Example 1. . This color filter has sharp edges and 20 more
The pattern did not collapse even after heating at 0 ° C for 20 minutes.

Example 6 A blue color filter was obtained in the same manner as in Example 1 except that the blue positive resist composition obtained in Example 3 was used instead of the red positive resist composition obtained in Example 1. . This color filter has sharp edges and 20 more
The pattern did not collapse even after heating at 0 ° C for 20 minutes.

Example 7 The following formula

[0031]

[Chemical 6]

A red positive resist composition was obtained in the same manner as in Example 1 except that 0.2 part of the photo-acid generator represented by was newly added.

Example 8 A quartz wafer was spin-coated with the positive resist composition obtained in Example 7, and then the solvent was evaporated. After exposing this silicon wafer, develop it with alkaline developer SOPD to 5μ
A positive colored pattern having a resolution of m was obtained. This was exposed on the entire surface and then heated at 120 ° C. for 5 minutes to obtain a red color filter.

[0034]

The positive resist composition of the present invention is excellent in various properties such as resolution and heat resistance. Further, according to the method of the present invention, a color filter excellent in various properties such as spectral characteristics can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a positive resist composition applied to a substrate.

FIG. 2 shows a state in which a quinonediazide compound and a photoacid generator in an exposed area have disappeared.

FIG. 3 is a positive type colored pattern after development.

FIG. 4 is a color filter that is cured after exposure on the entire surface.

[Explanation of symbols]

 1 Positive resist composition 2 Quinonediazide compound 3 Pigment 4 Photo acid generator 5 Substrate 6 Mask 7 Color filter

Claims (6)

[Claims] 1. A positive resist composition comprising a heat-curable resin, a quinonediazide compound, a crosslinking agent and a pigment. 2. A positive resist composition comprising an acid-curable resin, a quinonediazide compound, a photoacid generator, a crosslinking agent and a pigment. 3. The positive resist composition according to claim 1, wherein the resin curable by heat is a novolac resin, and the quinonediazide compound is an o-naphthoquinonediazide compound. 4. The positive resist composition according to claim 2, wherein the acid-curable resin is a novolac resin and the quinonediazide compound is an o-naphthoquinonediazide compound. 5. A cross-linking agent is represented by the following formula: — (CH ₂ ) _s OR (wherein R represents a hydrogen atom or a lower alkyl group, s
Represents an integer of 1 to 4. The positive resist composition according to any one of claims 1 to 4, which comprises a compound having a group represented by the formula (4). 6. A positive resist composition according to claim 1 is applied on a substrate, exposed through a mask, and the exposed portion is developed and removed to form a positive colored pattern. A method for producing a color filter, which comprises exposing and curing the entire colored pattern which is an unexposed portion.