KR20080011880A - Composition for improving the adhesiveness of the photosensitive organic insulating layer - Google Patents

Abstract

A composition for forming a photosensitive organic insulating layer, and an organic insulating layer prepared by using the composition are provided to improve the adhesion with a substrate remarkably and to enhance sensitivity. A composition for forming a photosensitive organic insulating layer comprises a photosensitive material; an alkali soluble resin; a solvent; and an acrylic copolymer containing a photosensitive group at terminal represented by the formula 1, wherein R, R1, R2 and R3 are independently H, CH3, an alkyl group or an aryl cyclic group; and a, b, c and d are independently an integer of 0-3. Preferably the composition comprises further a thermal acid generator represented by the formula 2, wherein R is an alkyl group or OH.

Description

Composition for improving the adhesiveness of the photosensitive organic insulating layer

1 is a view showing the structure of a thin film transistor formed in each pixel of a liquid crystal display element.

2A is a schematic cross-sectional view of a conventional pixel.

FIG. 2B is a schematic cross-sectional view of a high magnification pixel. FIG.

<Explanation of symbols for the main parts of the drawings>

10: substrate 11: SiNx organic insulating film

12: S / D electrode 13: n + -a-Si layer

14: a-Si layer 15: metal electrode

20: Black matrix 21: Liquid Crystal

22: passivation layer 23: ITO glass

24: column line

25: passivation layer with low dielectric constant

The present invention relates to a composition for forming a photoreactive organic insulating film and an organic insulating film prepared by using the same, and more particularly, to a photosensitive film containing a curing agent having an oxetane group by adding a thermal acid generator to a polymer of an alkali-soluble resin. In the resin composition, the alkali-soluble resin is an acrylic copolymer resin, and the solvent is a photosensitive resin composition characterized by a mixture of diethylene glycol methylethyl ether and a solvent having a vapor pressure at room temperature and normal pressure lower or higher than diethylene glycol methylethyl ether. It relates to an organic insulating film exhibiting solvent resistance in a subsequent photoresist process. In particular, an object of the present invention is to provide a photosensitive resin composition and an organic insulating film using the same, which can significantly improve adhesion by adding an acrylic copolymer containing a photosensitive group to the terminal. TFT-LCD (Thin Film Transistor Liquid Crystal Display) is formed by bonding a glass substrate on which TFT-array is formed and a glass substrate on which color filters are formed to maintain a constant gap, and then injecting liquid crystal between two glass substrates to form a panel. It refers to display by applying electric signal. LCD panels, however, do not actively emit light, so they need a separate light source, which is called a back-light. Among the characteristics of TFT-LCD, it is important to obtain low power consumption and high brightness. The method of achieving low power consumption can be classified into driving circuit technology, back-light technology, and panel technology.Panel related technologies can improve the transmission efficiency of flat plate, improve the transmittance of color filter, It is necessary to increase the aperture ratio of the TFT-array, that is, the area through which light passes. Opening ratio refers to the ratio of open or transparent portions to the total surface area. The recent results for TFT-LCD are focused on the improvement of optical reagent angle and pixel aperture ratio, and the high aperture ratio reduces the power consumption of the back light source by implementing high luminance. Until now, research has been carried out to obtain an aperture ratio of 80% or more, and most are based on the black matrix on TFT-array concept. Various designs and processes are being developed to achieve low power consumption and high brightness by increasing the aperture ratio. To this end, the first generation technology required expensive PECVD and Cry etcher equipment to form SiNx protective layer, but from the second generation technology using organic insulating film, the process can be performed without vacuum equipment, thus reducing the equipment investment cost. As a result, the number of processes progressed was reduced and the productivity of the clean room area was reduced. In order to be used as an organic insulating layer, a material having low electrical conductivity and high breakdown field characteristics is required. Currently used organic insulating films include polyimide (Korean Patent Publication No. 2003-0016981), polyvinyl alcohol (Korean Patent Publication No. 2002-0084427), poly (vinylphenol-maleimide) (Korean Patent Publication No. 2004- 0028010), photoacrylic (US Pat. No. 6,232,157), etc., but did not exhibit the device characteristics to replace the existing inorganic insulating film. In order to compensate for this drawback, the Korean patent application No. 2002-59061 has been improved significantly by providing an insulating polymer having a maleimide copolymer structure, but the problem of melting in the organic solvent used in the subsequent photolithography process still remains Existed. In order to realize a highly efficient organic insulating film, not only an organic active film material development but also an organic insulating film having excellent device characteristics capable of forming a thin film in a simplified process without affecting a substrate and a line processing film is urgently needed. In order to solve this problem, the present inventors mixed a photoacid generator, and in particular, a method of manufacturing an organic insulating film through UV irradiation and heat treatment by adding an acrylic copolymer containing a photosensitive group at the end to remarkably improve adhesion to a substrate. Suggested.

The present invention is to remarkably improve the adhesiveness with the above-described problems, in particular, the substrate, by adding an acrylic copolymer containing a photosensitive group at the end to improve the high sensitivity, heat resistance, chemical resistance, adhesion, etc. and improve the electrical properties It is to provide a photoreactive organic insulating film composition.

In addition, the present invention provides a method for manufacturing and evaluating a photosensitive organic insulating film having high sensitivity and excellent pattern formation, excellent etching property and light transmittance while achieving high sensitivity in a photolithography process.

In order to achieve the above object, the present invention provides a composition for forming a photosensitive organic insulating film containing a photosensitive material, an alkali-soluble resin, a solvent and an acrylic copolymer containing a photosensitive group at the terminal represented by the following formula (1).

[Formula 1]

(In Formula 1, R, R ₁ , R ₂ , and R ₃ are each independently any one of H, CH ₃ , an alkyl group, and an aryl cyclic group, and a, b, c, and d are each independently 0). , 1, 2, or 3.)

In addition, the present invention provides a composition for forming a photosensitive organic insulating film further comprising an adhesive aid and a thermal acid generator in the composition.

In addition, the present invention provides a composition for forming a photosensitive organic insulating film, wherein the thermal acid generator includes a compound represented by the following Chemical Formula 2.

[Formula 2]

(In Formula 2, R represents an alkyl group or a hydroxy group.)

The present invention also provides a composition for forming a photosensitive organic insulating film, wherein the photosensitive material is a compound having a quinonediazide group.

The present invention also provides a composition for forming a photosensitive organic insulating film, wherein the photosensitive material is a naphthoquinone diazide compound, and the alkali-soluble resin is an acrylic copolymer resin.

In addition, the present invention provides a composition for forming a photosensitive organic insulating film, the content of the acrylic copolymer containing a photosensitive group at the terminal represented by the formula (1) is 0.004 parts by weight to 0.020 parts by weight based on 100 parts by weight of the total content of the composition.

As the organic insulating film resin component in the present composition, an alkali-soluble resin is preferable, and an acrylic copolymer is particularly preferable. As this alkali-soluble resin, an acrylic copolymer, a polyester copolymer, a polystyrene copolymer, etc. are mentioned, for example. Of these, the methacrylic copolymer, which is an acrylic copolymer, is important. In order to impart chemical resistance and etching resistance as necessary, it is preferable to introduce cyclic hexane which is an allyl cyclyl structure or an epoxy or oxetane structure which is a curing group. Novolac resins made from phenols or cresols and aldehydes, polyvinyl alcohols, polyvinyl alkyl ethers, copolymers of styrene and acrylic acid, copolymers of methacrylic acid and methacrylic acid alkyl esters, polymers of hydroxy styrene, polyvinyl Hydroxy benzoate, polyvinyl hydroxybenzene, and the like. Moreover, the polymer containing the monomeric unit which has a carboxyl group is preferable.

Examples of the monomer having a carboxyl group include unsaturated carboxylic acids having at least one carboxyl group in the molecule, such as unsaturated monocarboxylic acid, unsaturated dicarboxylic acid, and the like. Specific examples thereof include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, and the like. These monomers are compounds having a carbon-carbon unsaturated bond, and can be used alone or in combination of two or more.

The alkali-soluble resin may be a homopolymer composed of a monomer having a carboxyl group, but the polymer is preferably a copolymer composed of a monomer different from a monomer having a carboxyl group. The said other monomer is a monomer which has a carbon-carbon unsaturated bond and can copolymerize with the monomer which has a carboxyl group. Specific examples thereof include aromatic vinyl compounds such as styrene, methylstyrene, vinyltoluene, and the like, unsaturated carboxylate compounds such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate and butyl meta Unsaturated aminoalkyl carboxylate compounds, such as acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, benzyl acrylate, benzyl methacrylate, such as aminoethyl acrylate, and the like Vinyl carboxylate compounds such as glycidyl methacrylate, such as vinyl carboxylate compounds such as vinyl acetate, vinyl propionate, vinyl cyanide compounds such as acrylonitrile, methacrylonitrile, -chloroacrylonitrile and the like Unsaturated oxetane carboxylate compounds, eg Vs 3-methyl-3-acryloxy methyl oxetane, 3-methyl-3-methacryloxy methyl oxetane, 3-ethyl-3-acryloxy methyl oxetane, 3-ethyl-3-methacryloxy methyl oxetane , 3-methyl-3-acryloxy ethyl oxetane, 3-methyl-3-methacryloxy ethyl oxetane, 3-methyl-3-acryloxy ethyl oxetane and 3-methyl-3-methacryloxy ethyl oxetane Etc. can be mentioned. These monomers are used individually or in combination of 2 or more types, respectively.

Examples of such copolymers include 3-ethyl-3-methacryloxy methyl oxetane / benzyl methacrylate / methacrylic acid copolymer, 3-ethyl-3-methacryloxy methyl oxetane / benzyl methacrylate / methacryl Acid / styrene copolymer, 3-ethyl-3-methacryloxy methyl oxetane / methyl methacrylate / methacrylic acid copolymer, 3-ethyl-3-methacryloxy methyl oxetane / methyl methacrylate / methacryl Acid / styrene copolymer etc. are mentioned.

Such a copolymer is preferably used 5 to 50% by weight. If the amount of the copolymer is less than 5% by weight, the obtained copolymer is hardly dissolved in the aqueous alkali solution. If the amount is more than 50% by weight, the solubility of the copolymer obtained in the aqueous alkali solution tends to be too high, leading to a decrease in the residual film ratio. Because it can cause. More preferably 10 to 30% by weight to use.

In the composition of the present invention, as the photosensitive material, any of those conventionally used as the photosensitive compound in the composition consisting of the resin component and the photosensitive compound can be used. Any photosensitive compound having a known quinonediazide can be used, but naphthoquinone-1,2-diazide-5-sulfonylchloride or naphthoquinone-1,2-diazide-4-sulfonylchloride Compounds having a functional group that can be condensed with may be used in combination, and such compounds are preferably phenol, paramethoxy phenol, hydroxyphenone, 2,4-dihydroxybenzophenone, aniline, and the like. Particular preference is given to compounds.

In the present invention, it is preferable to use the components of the composition dissolved in a solvent. As such a solvent, cellosolve tetrahydrofuran, such as a ketone solvent methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, such as acetone, methyl ethyl ketone, cyclopentanone, and cyclohexanone Propylene solvents, such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and ether solvents such as ethylene glycol monoethyl ester and ethylene glycol monoethyl ether such as diethylene glycol dimethyl ether and ethylene glycol monomethyl ether Lactic acid esters, such as glycol monoalkyl ether acetates methyl lactate and ethyl lactate, Aromatic hydrocarbons, such as toluene and xylene, etc. are preferable. These solvents may be used alone or in combination of two or more.

In order to significantly improve the adhesion in the composition of the present invention, an acrylic copolymer containing a photosensitive group at the terminal represented by the following formula (1) is used.

[Formula 1]

However, in Formula 1, R, R ₁ , R ₂ , and R ₃ are each independently any one of H, CH ₃ , an alkyl group, and an aryl cyclic group, and a, b, c, and d are each independently 0, 1, 2, or 3.

It is preferable to include 0.004 parts by weight to 0.020 parts by weight of the acrylic copolymer containing a photosensitive group at the terminal of Formula 1 based on 100 parts by weight of the total composition. When the content thereof is less than 0.004 parts by weight, it is difficult to see the effect of improving the adhesion without deteriorating the sensitivity. When the content thereof exceeds 0.020 part by weight, it is difficult to obtain the effect of increasing the adhesion in proportion to the increased content.

As an adhesive adjuvant component used for improving the adhesiveness with a board | substrate in the composition of this invention, the silane coupling agent which has reactive substituents, such as a carboxyl group, a methacrylyl group, an isocyanate group, an epoxy group, can be used. Specifically, trimethoxysilyl benzoic acid, γ-methacrylic propylpropyl methoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatepropyltriethoxysilane, γ-clisidoxypropyltrimethoxy Silane, β- (3,4-epoxy cyclohexyl) ethyltrimethoxysilane, and the like.

The thermal acid generator will be described as a component constituting the resin composition of the present invention. The thermal acid generator used in the present invention generates an acid by heating to promote an acid catalyst polymerization reaction. Preferred thermal acid generators include sulfonic compounds represented by the following general formulas.

[Formula 2]

(However, in the formula 2, R means an alkyl group or a hydroxy group.)

The thermal acid generator is used 0.1 to 5 parts by weight based on the total composition, more preferably 0.5 to 3 parts by weight. If the content is less than 0.1 part by weight, the effect of the thermal acid generator does not appear, and if it exceeds 3 parts by weight, it is difficult to control the flowability, the adhesiveness is poor, and the residual film rate is lowered. In the photosensitive resin composition of the present invention, the thermal acid generator in the composition serves to accelerate the curing of the film by generating an acid when performing the heat treatment process for thermal curing.

Example

Hereinafter, the present invention will be described in detail by way of examples. However, the scope of the present invention is not limited to these examples.

Examples 1-6 and Comparative Examples 1, 2

As the photosensitive material, a naphthoquinone diazide compound, an acrylic copolymer as an alkali-soluble resin component, and diethylene glycol methyl ethyl ether (EDM) as a solvent are blended, and an acrylic copolymer containing a photosensitive group at the terminal is added. As shown in Table 1, the composition was mixed while changing the composition ratio to prepare a photoresist composition. This composition was a h, g, i-ray photosensitive organic insulating film composition, which was filtered using a filter having a 0.2 mu m pore size.

The silicon wafer was spin-coated each photoresist composition in which the content of the acrylic copolymer containing the photosensitive group was changed at the terminal of the formula (1), and preliminarily dried at 100 ° C. for 120 seconds on a hot plate to obtain a film thickness of 0.95 μm. A photoresist film was formed. The wafer on which this film was formed was mask-exposed using the I-ray stepper. It is developed for 40 seconds in 0.4 wt% tetramethyl ammonium hydroxide (TMAH) aqueous solution, and after development, the residual film rate and adhesion are measured, and after exposing the entire surface with a mask aligner exposure machine, it is 220 ° C. in a dry oven. The cross section of the pattern after Hard Bake was observed under an electron microscope for time, and the residual film rate and transmittance were measured.

The results are shown in Table 1 below.

In Table 1, the effective sensitivity represents the exposure amount at which the CD size is matched in a dot pattern of 2.0 mu m. Adhesion was observed in the dot pattern on the silicon wafer not HMDS treatment, showing the degree of separation from the substrate, OO: very good, O: good, C: normal and X: bad.

TABLE 1

 Photosensitive material (parts by weight)  Resin component (parts by weight)  Solvent (parts by weight)  Compound of Formula 1 (parts by weight)  Effective Sensitivity (msec)  Post-development residual rate (%)  Adhesion  Compound components  Naphthoquinone diazide compound  Acrylic Copolymer (Alkali Soluble Resin)  EDM (1)  Acrylic copolymers containing photosensitive groups at the ends (2006.01) Example 1 4 16 80 0.004 112 74.30 O Example 2 4 16 80 0.006 123 78.00 O Example 3 4 16 80 0.008 145 82.00 O Example 4 4 16 80 0.010 165 86.40 O Example 5 4 16 80 0.020 165 95.20 OO Example 6 4 16 80 0.040 320 96.00 OO Comparative Example 1 4 16 80 - 179 95.9 X Comparative Example 2 6 16 78 - 190 97.7 X

1) EDM in (1) means diethylene glycol methylethyl ether.

2) The content of the photosensitive group-containing acrylic copolymer at the end of (2) at the end is a relative value with respect to 100% of the total content of the photosensitive material, the resin component and the solvent.

As can be seen in Table 1, the composition of Examples 1 to 6 of the present invention containing 0.004% to 0.020% of the photosensitive group-containing acrylic copolymer at the terminal of the formula (1) relative to 100 parts by weight of the total content of the composition While the effective sensitivity and the adhesion and heat resistance are very good, the compositions of Comparative Examples 1 and 2 without the content of the acrylic copolymer containing a photosensitive group at the terminal of Formula 1 have good effective sensitivity and residual film ratio after development. It can be seen that the adhesion is all poor.

As described above, in the present invention, by containing the acrylic copolymer containing a photosensitive group at the terminal of the formula (1), not only can the high sensitivity and low after-development residual film ratio be obtained, By improving, the organic insulating film for display liquid crystal display elements, H, G, I-line photoresist, etc. can be applied widely.

Claims (7)

A composition for forming a photosensitive organic insulating film containing a photosensitive material, an alkali-soluble resin, a solvent, and an acrylic copolymer containing a photosensitive group at the terminal represented by the following formula (1). [Formula 1]

However, in Formula 1, R, R ₁ , R ₂ , and R ₃ are each independently any one of H, CH ₃ , an alkyl group, and an aryl cyclic group, and a, b, c, and d are each independently 0, 1, 2, or 3. The composition for forming a photosensitive organic insulating film according to claim 1, further comprising an adhesion aid and a thermal acid generator. 3. The composition of claim 2, wherein the thermal acid generator comprises a compound represented by the following Chemical Formula 2. 4. [Formula 2]

However, in Formula 2, R is an alkyl group or a hydroxy group. The composition for forming a photosensitive organic insulating film according to any one of claims 1 to 3, wherein the photosensitive material is a compound having a quinone diazide group. The composition for forming a photosensitive organic insulating film according to any one of claims 1 to 3, wherein the photosensitive material is a naphthoquinone diazide compound, and the alkali-soluble resin is an acrylic copolymer resin. According to any one of claims 1 to 3, wherein the content of the acrylic copolymer containing a photosensitive group at the terminal represented by the formula (1) is 0.004 parts by weight to 0.020 parts by weight relative to 100 parts by weight of the total content of the composition A composition for forming a photosensitive organic insulating film. It produced using the composition in any one of Claims 1-3, The organic insulating film characterized by the above-mentioned.

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