Semiconductor device and method for manufacturing the same

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

forming a gate on a semiconductor substrate;

sequentially stacking a first oxide layer, a nitride layer and a second oxide layer on the semiconductor substrate, including the gate;

forming a first photoresist layer pattern on the second oxide layer;

forming a second oxide layer pattern by wet etching the second oxide layer, using the first photoresist layer pattern as a mask;

forming a nitride layer pattern by dry etching the nitride layer, using the second oxide layer pattern as a mask; and

forming a first oxide layer pattern by etching the first oxide layer by using the nitride layer pattern as a mask;

wherein before the step of forming the first oxide layer pattern, the method comprises removing polymers generated on at least one side of the nitride layer pattern by performing a Descum process.

2. The method of claim 1 , wherein before the step of forming the nitride layer pattern, the method further comprises:

forming a second photoresist layer pattern for forming the nitride layer pattern on the second oxide layer pattern, wherein the nitride layer is etched by using the second photoresist layer pattern as a mask.

3. The method of claim 1 , wherein the Descum process is performed by using O 2 and N 2 /H 2 gas.

4. The method of claim 1 , wherein the Descum process is performed at a temperature of 120° C. for 20 seconds.

5. The method of claim 1 , wherein the first oxide layer pattern is formed by wet etching the first oxide layer.

6. A method for manufacturing a semiconductor device, the method comprising the steps of:

forming a gate on a semiconductor substrate;

sequentially stacking a first oxide layer, a nitride layer and a second oxide layer on the semiconductor substrate, including the gate;

forming a first photoresist layer pattern on the second oxide layer;

forming a second oxide layer pattern by selectively etching the second oxide layer using the first photoresist layer pattern as a mask and removing the first photoresist layer pattern;

forming a nitride layer pattern by wet etching the nitride layer, using the second oxide layer pattern as a mask; and

forming a first oxide layer pattern by selectively etching the first oxide layer, using the nitride layer pattern as a mask.

7. The method of claim 6 , wherein before the step of forming the first oxide layer pattern, the method further comprises:

forming a second photoresist layer pattern on the nitride layer pattern for forming the first oxide layer pattern, wherein the first oxide layer is etched using the second photoresist layer pattern as a mask.

8. The method of claim 6 , wherein the second oxide layer pattern is formed by dry etching the second oxide layer.

9. The method of claim 8 , wherein before the step of forming the nitride layer pattern, the method further comprises:

removing polymers generated on at least one side of the second oxide layer pattern by performing a Descum process.

10. The method of claim 9 , wherein the Descum process is performed by using O 2 and N 2 /H 2 gas.

11. The method of claim 9 , wherein the Descum process is performed at a temperature of 120° C. for 20 seconds.

12. The method of claim 6 , wherein the second oxide layer pattern is formed by wet etching the second oxide layer.

13. The method of claim 12 , wherein before the step of forming the nitride layer pattern, the method further comprises:

forming a second photoresist layer pattern for forming the nitride layer pattern on the second oxide layer pattern, wherein the nitride layer is etched by using the second photoresist layer pattern as a mask.

14. The method of claim 6 , wherein the first oxide layer pattern is formed by wet etching the first oxide layer.