Method for fabricating semiconductor device using tungsten as sacrificial hard mask

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

forming a layer on an etch target layer, the etch target layer being an insulation layer;

forming a photoresist pattern on the layer;

etching the layer using a plasma containing CHF 3 gas by using the photoresist pattern as an etch mask to form a sacrificial hard mask; and

etching the etch target layer by using at least the sacrificial hard mask as an etch mask, thereby obtaining a predetermined pattern, wherein the predetermined pattern includes a pattern for forming a contact hole.

2. The method of claim 1 , wherein the predetermined pattern is one of a positive pattern and a negative pattern.

3. The method of claim 1 , wherein the layer is formed by employing a material selected from the group consisting of tungsten (W), tungsten silicide (WSi x ) and tungsten nitride.

4. The method of claim 3 , wherein at the step of forming the sacrificial hard mask, one gas selected from the group consisting of NF 3 , SF 6 and CF 4 is used in addition to the CHF 3 gas.

5. A method for fabricating a semiconductor device, comprising the steps of:

forming a conductive layer on a substrate;

forming an insulation layer on the conductive layer;

forming a tungsten-based layer on the insulation layer;

forming a photoresist pattern on the tungsten-based layer;

etching the tungsten-based layer by using the photoresist pattern as an etch mask to form a sacrificial hard mask;

etching the insulation layer by using at least the sacrificial hard mask as an etch mask along with a plasma containing oxygen gas to form a hard mask; and

etching the conductive layer by using at least the sacrificial hard mask as an etch mask to form a conductive pattern, wherein the conductive pattern includes a stack structure of the hard mask and the conductive layer.

6. The method of claim 5 , wherein the insulation layer is one of a single layer of nitride, a multilayer of nitride and stacked layers of oxide and nitride.

7. The method of claim 5 , wherein the insulation layer has a thickness ranging from approximately 1,500 Å to approximately 3,000 Å.

8. The method of claim 5 , wherein the tungsten-based layer includes one of tungsten (W), tungsten silicide (WSi x ) and tungsten nitride (WN).

9. The method of claim 5 , wherein the conductive pattern is one of a bit line, a word line and a metal line.

10. The method of claim 5 , wherein the step of forming the photoresist pattern proceeds with one of ArF photolithography and F 2 photolithography.

11. The method of claim 5 , wherein at the step of forming the sacrificial hard mask, a plasma containing CHF 3 gas is used.

12. The method of claim 11 , wherein at the step of forming the sacrificial hard mask, one gas selected from the group consisting of NF 3 , SF 6 and CF 4 is used in addition to the CHF 3 gas.

13. A method for fabricating a semiconductor device, comprising the steps of:

forming a conductive layer on a substrate;

forming an insulation layer on the conductive layer;

forming a tungsten-based layer on the insulation layer;

forming an anti-reflective coating layer on the tungsten-based layer;

forming a photoresist pattern on the anti-reflective coating layer;

etching the anti-reflective coating layer by using the photoresist pattern as an etch mask;

etching the tungsten-based layer by using at least the photoresist pattern as an etch mask to form a sacrificial hard mask

etching the insulation layer using a plasma containing O 2 gas by using at least the sacrificial hard mask as an etch mask to form a hard mask; and

etching the conductive layer by using at least the sacrificial hard mask as an etch mask to form a conductive pattern including a stack structure of the hard mask and the conductive layer.

14. The method of claim 13 , wherein the insulation layer is one of a single layer of nitride, a multilayer of nitride and stacked layers of oxide and nitride.

15. The method of claim 13 , wherein the insulation layer has a thickness ranging from approximately 1,500 Å to approximately 3,000 Å.

16. The method of claim 13 , wherein the tungsten-based layer includes one of tungsten (W), tungsten silicide (WSi x ) and tungsten nitride (WN).

17. The method of claim 13 , wherein at the step of forming the conductive pattern, the sacrificial hard mask is removed.

18. The method of claim 13 , after the step of forming the conductive pattern, further including the step of removing the sacrificial hard mask.

19. The method of claim 13 , wherein at the step of forming the sacrificial hard mask, a plasma containing CHF 3 gas is used.

20. The method of claim 19 , wherein at the step of forming the sacrificial hard mask, one gas selected from the group consisting of NF 3 , SF 6 and CF 4 is used in addition to the CHF 3 gas.