Methods for depositing fluorine/carbon-free conformal tungsten

1. A processing method comprising:

forming a tungsten containing film comprising sequentially exposing a substrate to a first reactive gas comprising a tungsten-containing compound comprising a compound with the empirical formula W x Cl 5x and a second reactive gas to form a tungsten-containing film having a thickness in the range of about 10 Å to about 30 Å; and

treating the tungsten-containing film by sequential exposure to TiCl 4 and ammonia to deposit less than about 1 Å of titanium nitride.

2. The method of claim 1 , wherein the second reactive gas comprises a hydrogen-containing compound and the tungsten-containing film is a tungsten film.

3. The method of claim 1 , wherein the second reactive gas comprises a nitrogen-containing compound and the tungsten-containing film comprises tungsten nitride.

4. The method of claim 1 , wherein the second reactive gas comprises a silicon-containing compound and the tungsten-containing film comprises tungsten silicide (WSi x ).

5. The method of claim 4 , wherein the second reactive gas further comprises hydrogen.

6. The method of claim 1 , wherein the second reactive gas comprises a mixture of a silicon-containing compound and a nitrogen-containing compound and the tungsten-containing film comprises tungsten-silicon-nitride (WSi x N y ).

7. The method of claim 1 , wherein the substrate is maintained at a temperature less than about 475° C.

8. The method of claim 2 , wherein the tungsten-containing film consists essentially of tungsten.

9. The method of claim 8 , wherein the substrate comprises a work function metal.

10. The method of claim 8 , wherein there is no intervening layer between the work function metal and the film consisting essentially of tungsten.

11. The method of claim 8 , wherein there is an intervening layer between the work function metal and the film consisting essentially of tungsten, the intervening layer having a thickness of less than about 5 Angstroms.

12. A processing method comprising

positioning a substrate in a processing chamber;

sequentially exposing at least a portion of the substrate to a first reactive gas and a second reactive gas at a temperature less than or equal to about 475° C. to form a tungsten-containing film having a thickness in the range of about 10 Å to about 30 Å, the first reactive gas comprising one or more of tungsten pentachloride, a compound with the empirical formula W x Cl 5x or tungsten hexachloride;

depositing a TiN film having a thickness less than about 1 Å on the tungsten-containing film; and

optionally repeating formation of a tungsten-containing film on the TiN film.

13. The method of claim 12 , wherein the second reactive gas comprises a hydrogen-containing compound and the tungsten-containing film is a tungsten film.

14. The method of claim 12 , wherein the second reactive gas comprises a nitrogen-containing compound and the tungsten-containing film comprises tungsten nitride.

15. The method of claim 12 , wherein the second reactive gas comprises a silicon-containing compound and the tungsten-containing film comprises tungsten silicide (WSi x ).

16. The method of claim 15 , wherein the second reactive gas further comprises hydrogen.

17. The method of claim 12 , wherein the second reactive gas comprises a mixture of a silicon-containing compound and a nitrogen-containing compound and the tungsten-containing film comprises tungsten-silicon-nitride (WSi x N y ).

18. The method of claim 12 , wherein prior to deposition of the tungsten-containing film, the substrate comprises a metallic layer.

19. The method of claim 12 , wherein prior to deposition of the tungsten-containing film, the substrate comprises an oxide layer and the method further comprises soaking the substrate with disilane or a mixture of hydrogen and silane at a partial pressure in the range of about 5 to about 20 Torr.

20. The method of claim 12 , wherein the tungsten containing film grows at a rate in the range of about 0.2 Å/cycle and about 3 Å/cycle.