Method for forming fine pattern of semiconductor device

1. A method for forming a pattern for a semiconductor device, the method comprising:

providing a semiconductor substrate including an underlying layer;

forming a first photoresist pattern over the underlying layer;

light exposing the first photoresist pattern to generate acid from the first photoresist pattern;

bleaching the first photoresist pattern to make the first photoresist pattern non-reactive to light exposure;

forming a second photoresist film over the underlying layer and the first photoresist pattern that has been made non-reactive to the light exposure;

light exposing the second photoresist film to form a second photoresist pattern, so that the first and second photoresist patterns are provided over the underlying layer.

2. The method according to claim 1 , wherein the light exposure step for the first photoresist pattern is performed with an exposure energy ranging from about 30 mJ/cm 2 to about 200 mJ/cm 2 .

3. The method according to claim 1 , wherein the light exposure for the first photoresist pattern is performed with an exposure energy ranging from about 80 mJ/cm 2 to about 120 mJ/cm 2 .

4. The method according to claim 1 , wherein the bleaching process for the first photoresist pattern is performed using a basic material with one selected from the group consisting of triethyl amine, Hex Methyl Di-Silane (HMDS), ammonia, methyl amine and combinations thereof.

5. The method according to claim 1 , wherein the bleaching process involves a wet method.

6. The method according to claim 5 , wherein the bleaching process comprises:

inserting the semiconductor substrate including the first photoresist pattern in a bleaching solution for about 50˜70 seconds; and

spin-dehydrating the semiconductor substrate.

7. The method according to claim 1 , wherein the bleaching process involves a dry method.

8. The method according to claim 7 , wherein the dry bleaching process is performed by spraying a bleaching material over the semiconductor substrate at a temperature of about 60° C. or less.

9. The method according to claim 1 , wherein the first photoresist pattern includes a plurality of structures and the second photoresist pattern includes a plurality of structures, wherein the structures of the first photoresist pattern are interweaved with the structures of the second photoresist pattern.

10. The method according to claim 9 , wherein the second photoresist film includes C 4 -C 8 alcohol as a solvent.

11. The method according to claim 10 , wherein the solvent is selected from the group consisting of 1-butanol, 2-butanol, 2-methyl-1-propanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1,2-dimethyl-1-propanol, 1-hexanol, 2-hexanol, 3-hexanol, 2-methyl-pentanol, 3-methylpentanol, 4-methylpentanol, 1,3-dimethylbutanol, 1,2-dimethylbutanol, heptanol, octanol and combinations thereof.

12. The method according to claim 9 , wherein the structures of the first photoresist pattern have a first pitch, and the structures of the second photoresist pattern have substantially the first pitch.

13. The method according to claim 12 , wherein the structures of the first and second photoresist patterns together define a second pitch that is less than the first pitch, wherein the second pitch about ½ of the first pitch.

14. The method according to claim 1 , further comprising a hard mask layer and an anti-reflection film at the interface between the first photoresist pattern and the semiconductor substrate.

15. The method according to claim 1 , wherein the underlying layer is the semiconductor substrate.

16. A method for forming a pattern over a substrate, the method comprising:

providing the substrate including an underlying layer;

forming a first pattern over the underlying layer, the first pattern configured to chemically react when exposed to light, the first pattern having a plurality of first structures having a pitch;

converting the first pattern to a second pattern that does not chemically react when exposed to light, the second pattern having a plurality of second structures having the same pitch as the first structures;

forming a film over the second pattern and the underlying layer, the film configured to chemically react when exposed to light;

light exposing the film to form a third pattern having a plurality of third structures having a pitch, so that the second and third patterns are provided over the underlying layer; and

transferring the second and third patterns to the underlying layer.

17. The method of claim 16 , wherein the second structures and the third structures are provided in an alternating arrangement.

18. The method of claim 16 , wherein the first pattern and the second pattern are photoresist patterns, and the second pattern is the first pattern that has been bleached to be non-reactive to light exposure.

19. The method of claim 16 , wherein the underlying layer is the substrate.

20. The method of claim 16 , wherein the first, second, and third structures have substantially the same pitch.