Method for forming patterns of semiconductor device
Provided is a method for forming patterns of a semiconductor device. According to the method, first mask patterns may be formed on a substrate, and second mask patterns may be formed on sidewalls of each first mask pattern. Third mask patterns may fill spaces formed between adjacent second mask patterns, and the second mask patterns may be removed. A portion of the substrate may then be removed using the first and third mask patterns as etch masks.
1. A method for forming a pattern, the method comprising:
forming first mask patterns on a substrate;
forming second mask patterns on sidewalls of the first mask patterns;
forming third mask patterns at least partially filling spaces between adjacent second mask patterns;
removing the second mask patterns, after forming the third mask patterns; and
removing a portion of the substrate using the first and third mask patterns as etch masks, wherein
each of the first mask patterns and the third mask patterns is formed of an organic layer containing silicon, and
each of the second mask patterns is formed of an organic layer without silicon and is removed using oxygen plasma ashing to form a mask layer including the first mask patterns and the third mask patterns, wherein
the first mask patterns are arranged in a striped shape having a pitch,
the second mask patterns are arranged on the sidewalls and an upper surface of the first mask patterns,
forming the third mask patterns includes,
forming a photoresist containing silicon on the first and second mask patterns to fill the spaces between the adjacent second mask patterns, and
removing an upper portion of the photoresist until the second mask patterns on the first mask patterns are exposed, and
the second mask patterns cover an entirety of the sidewalls of the first mask patterns and an entirety of the upper surface of the first mask patterns such that the first mask patterns are protected by the second mask patterns during the removing of the upper portion of the photoresist.
2. The method of claim 1 , wherein removing of the plurality of second mask patterns includes forming a silicon oxide layer on the first and third mask patterns.
3. The method of claim 1 , wherein,
each of the first, second, and third mask patterns is formed of a photoresist;
the second mask patterns have a higher developing speed than a developing speed of the first and third mask patterns; and
the second mask patterns are removed based a difference between the higher developing speed of the second mask patterns and the developing speed of the first and third mask patterns.
4. The method of claim 3 , wherein each of the first and third mask patterns is formed having a first width larger than a target width, and removing the second mask patterns reduces the first width of the first and third mask patterns to the target width.
5. The method of claim 1 , wherein the first mask patterns are arranged in a stripe shape having a pitch.
6. The method of claim 1 , wherein the second mask patterns are formed using chemical absorption.
7. The method of claim 1 , wherein the second mask patterns are formed on the sidewalls of the first mask pattern to have a thickness substantially equal to a width of each of the plurality of first mask patterns.
8. The method of claim 1 , wherein a width between the adjacent second mask patterns is substantially equal to the width of each of the first mask patterns.
9. The method of claim 1 , wherein a width of the spaces between adjacent first mask patterns is three times a width of each of the first mask patterns, and a thickness of the second mask patterns on the sidewalls of the first mask patterns is substantially equal to the width of each of the first mask patterns.
10. The method of claim 1 , further comprising:
forming a fourth organic mask pattern on a region of the substrate, wherein
the removing the portion of the substrate includes etching a portion of the region using the fourth organic mask pattern as an etch mask.
11. The method of claim 1 , further comprising:
curing a surface of the second mask patterns before forming the third mask patterns using at least one of Ar plasma treatment, HBR plasma treatment, UV curing, E-Beam curing, and Ar implantation.
12. The method of claim 1 , wherein forming the third mask patterns comprises:
forming a photoresist containing silicon on the second mask patterns; and
etching an upper portion of the photoresist containing silicon until a height of the photoresist containing silicon is substantially equal to a height of the first mask patterns.
13. The method of claim 12 , wherein etching the upper portion is performed with a surfactant rinse solution that includes an alcohol compound containing ethylene glycol and poly propylene glycol, and the alcohol compound includes one to ten carbons, and has one selected from the group including of mon-, di-, triple-, and multi-alcohol function groups.
14. The method of claim 12 , wherein forming the third mask pattern comprises:
coating a water-soluble layer containing an acid; and
baking the coated water-soluble layer.
15. The method of claim 1 , wherein,
the first mask patterns are photoresist patterns and arranged in a stripe shape having a constant pitch;
the second mask patterns are photoresist patterns having a faster removing speed than a removing speed of the first mask patterns and the third mask patterns;
the third mask patterns are photoresist patterns; and
the second mask patterns are removed using oxygen plasma aching to form a mask layer including the first mask patterns and the third mask patterns.
16. The method of claim 15 , wherein each of the first and third mask patterns is formed having a first width larger than a target width, and removing the second mask patterns reduces the first width of the first and third mask patterns to the target width.
17. The method of claim 1 , wherein removing the second mask patterns includes exposing a portion of substrate between the first mask patterns and the third mask patterns adjacent to each other.
18. The method of claim 1 , wherein forming the third mask patterns is free of an exposure process.
19. The method of claim 1 , further comprising:
forming a first pattern and a second pattern under the first mask pattern and the third mask pattern adjacent to each other, wherein
the first pattern and the second pattern are formed by removing a portion of the substrate using the first and the third mask patterns adjacent to each other as etch masks, and
the first pattern is separated from the second pattern.
20. The method of claim 1 , further comprising:
patterning a photoresist on another region to form fourth mask patterns before the removing of the portion of the substrate, wherein,
the photoresist for the third mask patterns is formed on the another region of the substrate separated from a region of the substrate on which the first, second and third mask patterns are formed,
the removing of the upper portion of the photoresist further includes removing an upper portion of the photoresist on the another region.
21. The method of claim 1 , wherein the forming of the second mask patterns forms the second mask patterns without anisotropic etching.