Photoresist composition, method of patterning thin film using the same, and method of manufacturing liquid crystal display panel using the same

1. A photoresist composition used in a display device, comprising:

an alkali-soluble phenol polymer in an amount of 10 to 70 parts by weight, including at least one unit of Formula 1;

a photo-acid generator in an amount of 0.5 to 10 parts by weight;

a dissolution inhibitor in an amount of 5 to 50 parts by weight, including at least one unit of Formula 2; and

a solvent in an amount of 10 to 90 parts by weight,

wherein the amounts of the foregoing components is based on a total of 100 parts by weight of alkali-soluble phenol polymer, photo-acid generator, dissolution inhibitor, and solvent;

wherein R is a methyl group,

wherein at least one of R 1 , R 2 and R 3 is a t-butyl vinyl ether protective group.

2. The photoresist composition according to claim 1 , wherein the alkali-soluble phenolic polymer comprises a hydroxyl group, wherein the alkali-soluble phenol polymer comprises: an alkali-soluble novolak formed by condensing an aldehyde with a substituted phenol selected from ortho-cresol, meta-cresol, para-cresol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, or a mixture comprising at least one of the foregoing substituted phenols; a poly (vinyl phenol), including poly (para-hydroxy-styrene), poly (para-hydroxy-alphamethylstyrene), a copolymer comprising at least one of para-hydroxy-styrene, para-hydroxy-alphamethylstyrene, or acetoxystyrene, an acrylic acid/methacrylic acid copolymer, a hydroxyphenylalkylcarbonyl polymer, or a novolak/poly (vinyl phenol) copolymer; or a combination comprising at least one of the foregoing alkali-soluble phenol polymers.

3. The photoresist composition according to claim 1 , wherein the photo-acid generator is selected from a diazonium salt, an iodonium salt, a sulfonium salt, a diazosulfonyl compound, a sulfonyloxyimide, a nitrobenzyl sulfonate ester, a triazine, an oxazole, an oxadiazole, a thiazole, a phenolsulfonic acid ester, a bis-sulfonylmethane, a bis-sulfonyldiazomethane, triphenylsulfonium tris (trifluoromethylsulfonyl) methide, diphenyl iodonium bis(trifluoromethylsulfonyl) imide, or a mixture comprising at least one of the foregoing photo-acid generators.

4. The photoresist composition according to claim 1 , wherein the dissolution inhibitor is obtained by dissolving trihydroxybenzophenone and t-butyl vinyl ether in acetone and reacting at room temperature in the presence of a base to convert the t-butyl vinyl ether to the t-butyl vinyl ether protective group, wherein the conversion of t-butyl vinyl ether to t-butyl vinyl ether protective group is 60 to 95%, as calculated on a per-mole basis.

5. The photoresist composition according to claim 1 , further comprising a basic additive for suppressing an undercut phenomenon in an amount of 1 to 9.99 parts by weight based on a total of 100 parts by weight of alkali-soluble phenol polymer, photo-acid generator, dissolution inhibitor, and solvent.

6. The photoresist composition according to claim 5 , wherein the basic additive is an amine, ammonium hydroxide, a photosensitive base, tetrabutyl ammonium hydroxide, triethanol amine, diethanol amine, trioctyl amine, n-octyl amine, trimethylsulfonium hydroxide, or triphenylsulfonium hydroxide.

7. A method of patterning a thin film, comprising:

forming a thin film on a substrate;

forming on the thin film a photoresist layer which includes an alkali-soluble phenol polymer in an amount of 10 to 70 parts by weight including at least one unit of Formula 1, a photo-acid generator in an amount of 0.5 to 10 parts by weight, a dissolution inhibitor in an amount of 5 to 50 parts by weight, including at least one unit of Formula 2, and a solvent in an amount of 10 to 90 parts by weight, wherein the amounts of the foregoing components is based on a total of 100 parts by weight of alkali-soluble phenol polymer, photo-acid generator, dissolution inhibitor, and solvent;

forming a photoresist pattern by patterning the photoresist layer by exposure and developing processes; and

etching the thin film by using the photoresist pattern as a mask;

wherein R is a methyl group,

wherein at least one of R 1 , R 2 and R 3 is a t-butyl vinyl ether protective group.

8. The method according to claim 7 , wherein the alkali-soluble phenol polymer comprises an alkali-soluble phenol polymer binder resin including a hydroxyl group selected from: an alkali-soluble novolak polymer comprising an aldehyde condensed with a substituted phenol including ortho-cresol, meta-cresol, para-cresol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, or a mixture comprising at least one of the foregoing substituted phenols; a poly (vinyl phenol) polymer selected from, poly (para-hydroxy-styrene), poly (para-hydroxy-alphamethylstyrene), a copolymer comprising at least one of para-hydroxy-styrene, para-hydroxy-alphamethylstyrene, or acetoxystyrene, an acrylic acid/methacrylic acid copolymer, a hydroxyphenylalkylcarbonyl polymer, or novolak/poly (vinyl phenol) copolymer; or a combination comprising at least one of the foregoing alkali-soluble phenol polymers.

9. The method according to claim 7 , wherein the photo-acid generator is selected from a diazonium salt, an iodonium salt, a sulfonium salt, a diazosulfonyl compound, a sulfonyloxyimide, a nitrobenzyl sulfonate ester, a triazine, an oxazole, an oxadiazole, a thiazole, a phenolsulfonic acid ester, a bis-sulfonylmethane, a bis-sulfonyldiazomethane, triphenylsulfonium tris (trifluoromethylsulfonyl) methide, diphenyl iodonium bis (trifluoromethylsulfonyl) imide, or a mixture comprising at least one of the foregoing photo-acid generators.

10. The method according to claim 7 , wherein the dissolution inhibitor is obtained by dissolving trihydroxybenzophenone and t-butyl vinyl ether in acetone and reacting at room temperature in the presence of a base to convert the t-butyl vinyl ether to the t-butyl vinyl ether protective group, wherein the conversion of t-butyl vinyl ether to t-butyl vinyl ether protective group is 60 to 95%, as calculated on a per-mole basis.

11. The method according to any one of claims 7 to 10 , wherein the photoresist further includes a basic additive for suppressing an undercut phenomenon in an amount of 1 to 9.99 parts by weight, based on a total of 100 parts by weight of alkali-soluble phenol copolymer, photo-acid generator, dissolution inhibitor, and solvent.

12. The method according to claim 11 , wherein the basic additive is an amine, ammonium hydroxide, a photosensitive base, tetrabutyl ammonium hydroxide, triethanol amine, diethanol amine, trioctyl amine, n-octyl amine, trimethylsulfonium hydroxide, or triphenylsulfonium hydroxide.

13. A method of manufacturing a liquid crystal display panel, comprising:

forming a thin film transistor substrate, including a thin film transistor so formed as to be connected to a gate line and a data line on a lower substrate, a passivation layer for protecting the thin film transistor, and a pixel electrode connected to the thin film transistor on the passivation layer; and

forming a color filter substrate, wherein the color filter substrate includes a black matrix for dividing a pixel region on an upper substrate which faces the lower substrate with liquid crystals disposed therebetween, a color filter formed in the pixel region, and a common electrode for forming an electric field with the pixel electrode;

wherein at least one of the thin film transistor, the passivation layer, the pixel electrode, the black matrix, the color filter, and the common electrode is formed by a patterning process using a photoresist which includes an alkali-soluble phenol polymer in an amount of 10 to 70 parts by weight including at least one unit of Formula 1, a photo-acid generator in an amount of 0.5 to 10 parts by weight, a dissolution inhibitor in an amount of 5 to 50 parts by weight and including at least one unit of Formula 2, and a solvent in an amount of 10 to 90 parts by weight, wherein the amounts of the foregoing components is based on a total of 100 parts by weight of alkali-soluble phenol polymer, photo-acid generator, dissolution inhibitor, and solvent, wherein Formulas 1 and 2 have the following structures;

wherein R is a methyl group,

wherein at least one of R 1 , R 2 and R 3 is a t-butyl vinyl ether protective group.

14. The method according to claim 13 , wherein the photoresist further comprises a basic additive for suppressing an undercut phenomenon in an amount of 1 to 9.99 parts by weight based on a total of 100 parts by weight of alkali-soluble phenol polymer, photo-acid generator, dissolution inhibitor, and solvent.

15. The method according to claim 14 , wherein the basic additive is an amine, ammonium hydroxide, a photosensitive base, tetrabutyl ammonium hydroxide, triethanol amine, diethanol amine, trioctyl amine, n-octyl amine, trimethylsulfonium hydroxide, or triphenylsulfonium hydroxide.

16. The photoresist composition according to claim 1 , wherein R 1 , R 2 and R 3 are the same or different and are hydrogen or a t-butyl vinyl ether protective group.

17. The method according to claim 7 , wherein R 1 , R 2 and R 3 are the same or different and are hydrogen or a t-butyl vinyl ether protective group.

18. The method according to claim 13 , wherein R 1 , R 2 and R 3 are the same or different and are hydrogen or a t-butyl vinyl ether protective group.