Semiconductor device and method of manufacturing the same

1. A method of manufacturing a semiconductor device, comprising:

forming first patterns on a workpiece layer;

forming second patterns containing a first metal on side faces of the first patterns;

removing the first patterns after forming the second patterns;

forming third patterns on side faces of the second patterns by a chemical change of the first metal after removing the first patterns;

removing the second patterns after forming the third patterns; and

processing the workpiece layer by using the third patterns as a mask after removing the second patterns.

2. The method of claim 1 , wherein the chemical change of the first metal is oxidation of the first metal.

3. The method of claim 2 , wherein the first metal is oxidized by ashing with an oxygen gas.

4. The method of claim 3 , wherein the ashing of the first metal is performed with the oxygen gas and a nitrogen gas.

5. The method of claim 1 , wherein the second patterns are formed of an elemental metal layer containing the first metal.

6. The method of claim 1 , wherein the third patterns are formed to form a first gap between first side faces of the third patterns and to form a second gap between second side faces of the third patterns, the second faces being more inclined than the first side faces, a width of a bottom face of the first gap and a width of a bottom face of the second gap being 0.5 to 1.5 times of a width of bottom faces of the second patterns.

7. The method of claim 1 , further comprising:

forming a first film on the third patterns after forming the third patterns,

planarizing a surface of the first film to expose the second patterns from the third patterns, and

removing the exposed second patterns and the first film.

8. A method of manufacturing a semiconductor device, comprising:

forming first patterns on a workpiece layer;

forming second patterns containing a first metal on side faces of the first patterns;

removing the first patterns after forming the second patterns;

forming third patterns on side faces of the second patterns by a chemical change of the first metal after removing the first patterns;

forming fourth patterns containing a second metal between the third patterns;

removing the third patterns after forming the fourth patterns; and

processing the workpiece layer by using the second and fourth patterns as a mask after removing the third patterns.

9. The method of claim 8 , wherein the chemical change of the first metal is oxidation of the first metal.

10. The method of claim 9 , wherein the first metal is oxidized by ashing with an oxygen gas.

11. The method of claim 10 , wherein the ashing of the first metal is performed with the oxygen gas and a nitrogen gas.

12. The method of claim 8 , wherein the second patterns are formed of an elemental metal layer containing the first metal.

13. The method of claim 8 , wherein the second metal is a same metal as the first metal.

14. The method of claim 8 , wherein the second metal is a different metal from the first metal.

15. The method of claim 8 , wherein the third patterns are formed to form a first gap between first side faces of the third patterns and to form a second gap between second side faces of the third patterns, the second faces being more inclined than the first side faces, a width of a bottom face of the first gap and a width of a bottom face of the second gap is 0.5 to 1.5 times of a width of bottom faces of the second patterns.

16. The method of claim 8 , further comprising:

forming a first film on the third patterns after forming the third patterns, and

planarizing a surface of the first film to expose the second patterns from the third patterns and to form the fourth patterns of the first film.