Photoresist coating composition and method for forming fine pattern using the same

1. A method for forming a photoresist pattern, comprising:

(a) coating a photoresist composition on an underlying layer of a semiconductor substrate;

(b) performing a soft-bake onto the resultant structure of (a) to form a photoresist film;

(c) exposing the photoresist film of (b) to light;

(d) performing a post-bake onto the resulting structure of (c);

(e) developing the resulting structure of (d) to form a first photoresist pattern; and

(f) coating the coating composition on the first photoresist pattern to form a second photoresist pattern;

wherein the coating composition consists of i) a water-soluble polymer having a repeating unit represented by the Formula 1, ii) an aqueous solvent and iii) an additive selected from the group consisting of a C 1 -C 10 alkyl alcohols and a C 2 -C 10 alkoxy alkyl alcohols:

wherein R 1 and R 2 are individually selected from the group consisting of H, linear and branched C 1 -C 20 alkyl groups, halogen, and —CN groups; R 3 is selected from the group consisting of methyl, ethyl, propyl, butyl, octyl, octyl phenyl, nonyl, nonyl phenyl, decyl, decyl phenyl, undecyl, undecyl phenyl, dodecyl and dodecyl phenyl; R 4 is selected from the group consisting of Na, NH(R 5 ) 3 and N(R 6 ) 4 wherein R 5 and R 6 are individually selected from the group consisting of methyl, ethyl, propyl, butyl, octyl, octyl phenyl, nonyl, nonyl phenyl, decyl, decyl phenyl, undecyl, undecyl phenyl, dodecyl, and dodecyl phenyl; and n is an integer ranging from 10 to 3000.

2. The method of claim 1 , wherein the light source of (c) is selected from the group consisting of KrF (248 nm), ArF (193 nm), VUV (157 nm), EUV (13 nm), E-beam, X-ray, and ion beam.

3. The method of claim 1 , comprising performing the coating process of (f) by spraying the coating composition on a rotating wafer on which the first photoresist pattern is formed.

4. The method of claim 1 , wherein the size of the second photoresist pattern is smaller by 10% to 30% than that of the first photoresist pattern.

5. The method of claim 1 , wherein the water-soluble polymer of Formula 1 is selected from the group consisting of poly(anetholesulfonic acid, sodium salt), poly(anetholesulfonic acid, triethylamine salt) and poly(anetholesulfonic acid, ammonium salt), and combinations thereof.

6. The method of claim 1 , wherein the water-soluble polymer of Formula 1 is present in an amount ranging from 0.001 to 5 parts by weight based on 100 parts by weight of the aqueous solvent.

7. The method of claim 1 , wherein the aqueous solvent is H 2 O.

8. The method of claim 1 , wherein the additive is a C 1 -C 10 alkyl alcohol selected from the group consisting of methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol, t-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2,2-dimethyl-1-propanol, and combinations thereof.

9. The method of claim 1 , wherein the additive is a C 2 -C 10 alkoxy alkyl alcohol selected from the group consisting of 2-methoxyethanol, 2-(2-methoxyethoxy) ethanol, 1-methoxy-2-propanol, 3-methoxy-1 ,2-propandiol, and combinations thereof.

10. The method of claim 1 , wherein the additive is present in an amount ranging from 1 to 10 parts by weight based on 100 parts by weight of the aqueous solvent.

11. The method of claim 10 , wherein the additive is present in an amount ranging from 1 to 3 parts by weight based on 100 parts by weight of the aqueous solvent.

12. A method for forming a photoresist pattern, comprising:

(a) coating a photoresist composition on an underlying layer of a semiconductor substrate;

(b) performing a soft-bake onto the resultant structure of (a) to form a photoresist film;

(c) exposing the photoresist film of (b) to light;

(d) performing a post-bake onto the resulting structure of (c);

(e) developing the resulting structure of (d) to form a first photoresist pattern; and

(f) coating the coating composition on the first photoresist pattern to form a second photoresist pattern;

wherein the coating composition consists of (i) a water-soluble polymer selected from the group consisting of poly(anetholesulfonic acid, sodium salt), poly(anetholesulfon ic acid, triethylamine salt) and poly(anetholesulfonic acid, ammonium salt), and combinations thereof, (ii) an aqueous solvent and (iii) an additive selected from the group consisting of C 1 -C 10 alkyl alcohols and C 2 -C 10 alkoxy alkyl alcohols.

13. The method of claim 12 , wherein the light source of (c) is selected from the group consisting of KrF (248 nm), ArF (193 nm), VUV (157 nm), EUV (13 nm), E-beam, X-ray, and ion beam.

14. The method of claim 12 , comprising performing the coating process of (f) by spraying the coating composition on a rotating wafer on which the first photoresist pattern is formed.

15. The method of claim 12 , wherein the size of the second photoresist pattern is smaller by 10% to 30% than that of the first photoresist pattern.

16. The method of claim 12 , wherein the water-soluble polymer is present in an amount ranging from 0.001 to 5 parts by weight based on 100 parts by weight of the aqueous solvent.

17. The method of claim 12 , wherein the aqueous solvent is H 2 O.

18. The method of claim 12 , wherein the additive is a C 1 -C 10 alkyl alcohol selected from the group consisting of methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol, t-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2,2-d imethyl-1-propanol, and combination thereof.

19. The method of claim 12 , wherein the additive is a C 2 -C 10 alkoxy alkylalcohol selected from the group consisting of 2-methoxyethanol, 2-(2-methoxyethoxy) ethanol, 1-methoxy-2-propanol, 3-methoxy-1 ,2-propandiol and combination thereof.

20. The method of claim 12 , wherein the additive is present in an amount ranging from 1to 10 parts by weight based on 100 parts by weight of the aqueous solvent.

21. The method of claim 20 , wherein the additive is present in an amount ranging from 1 to 3 parts by weight based on 100 parts by weight of the aqueous solvent.