Method for forming a device having multiple silicide types

1. A method for fabricating a device on a semiconductor substrate, comprising:

depositing a first metal layer on a first region and a second region, wherein the first metal layer comprises at least a first metal;

depositing a second metal layer on the first region and the second region, wherein the second metal layer comprises at least a second metal;

selectively removing one of the first metal layer and the second metal layer from the second region; and

subsequent to the selectively removing, forming a first silicide comprising the first and second metals on the first region, and forming a second silicide comprising the first or second metal that was not removed from the second region.

2. The method of claim 1 further comprising removing an un-reacted portion of the first metal and the second metal after forming the first silicide and the second silicide.

3. The method of claim 1 wherein forming the first silicide and the second silicide includes high temperature processing.

4. The method of claim 1 wherein the first region comprises a first gate stack with a first source/drain opposite and adjacent to the first gate stack, and wherein the second region comprises a second gate stack with a second source/drain opposite and adjacent to the second gate stack.

5. The method of claim 1 wherein one of the first region and the second region is a NMOS and the other is a PMOS.

6. The method of claim 1 wherein the first metal is nickel and the second metal is cobalt.

7. The method of claim 1 wherein depositing the first metal layer and the second metal layer comprises sputtering.

8. The method of claim 1 wherein depositing the first metal layer and the second metal layer comprises physical vapor deposition (PVD), plating, chemical vapor deposition (CVD), or a combination thereof.

9. The method of claim 1 wherein CVD comprises plasma enhanced CVD (PECVD), atmospheric pressure CVD (APCVD), low pressure CVD (LPCVD), high density plasma CVD (HDPCVD), atomic layer CVD (ALCVD), or combination thereof.

10. The method of claim 1 wherein selectively removing comprises:

photolithography processing; and

etching.

11. A method for fabricating a device on a semiconductor substrate, the method comprising:

depositing a hard mask layer on a first region and a second region;

selectively removing the hard mask layer from the first region;

depositing a first metal layer on the first region and the second region, wherein the first metal layer comprises a first metal;

forming a first silicide comprising the first metal on the first region;

removing an unreacted portion of the first metal from the first region and the second region;

removing the hard mask from the second region;

depositing a second metal layer on the first region and the second region, wherein the second metal layer comprises a second metal that is different from the first metal; and

forming a second silicide comprising the first metal and the second metal on the first region, and forming a third silicide comprising the second metal on the second region.

12. The method of claim 11 wherein the hard mask layer is selected from a group consisting silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, high k material, and a combination thereof.

13. The method of claim 11 wherein forming the hard mask layer comprises PVD, CVD, high temperature reaction, or a combination thereof.

14. The method of claim 11 wherein forming the hard mask layer comprises reacting dichlorosilane (SiCl 2 H 2 ) and ammonia (NH 3 ).

15. The method of claim 11 wherein depositing the first metal layer and the second metal layer comprises sputtering.

16. The method of claim 11 wherein depositing the first metal layer and the second metal layer comprises CVD.

17. A method for fabricating a device on a semiconductor substrate, the method comprising:

depositing a first metal layer on first and second regions, wherein the first metal layer comprises a first metal;

depositing a second metal layer on the first and second regions, wherein the second metal layer comprises a second metal;

depositing a third metal layer on the first and second regions, wherein the third metal layer comprises the first metal;

selectively removing one of the first metal layer and the third metal layer from the second region; and

forming a first silicide comprising the first metal and the second metal on the first region and a second silicide comprising the first metal and the second metal on the second region, wherein the first silicide has a greater percentage of the first metal than does the second silicide.

18. The method of claim 17 wherein selectively removing one of the first metal layer and the third metal layer from the second region includes selectively removing the first metal layer prior to depositing the second metal layer.

19. The method of claim 17 wherein selectively removing one of the first metal layer and the third metal layer from the second region includes selectively removing the third metal layer after depositing the third metal layer.

20. The method of claim 17 wherein one of the first metal and the second metal is nickel and the other is cobalt.

21. The method of claim 17 wherein depositing the first metal layer, depositing the second metal layer, and depositing the third metal layer comprises sputtering.

22. The method of claim 17 wherein depositing the first metal layer, depositing the second metal layer, and depositing the third metal layer comprises CVD.