Semiconductor device and method for manufacturing the same

1. A semiconductor device, comprising an n-channel field effect transistor and a p-channel field effect transistor formed on a semiconductor substrate, wherein:

a gate electrode of one of the n-channel field effect transistor and the p-channel field effect transistor includes a metal-containing layer in contact with a gate insulating film, and a first silicon-containing layer formed on the metal-containing layer;

a gate electrode of the other one of the n-channel field effect transistor and the p-channel field effect transistor includes a second silicon-containing layer in contact with a gate insulating film, a conductive oxide layer formed on the second silicon-containing layer, another metal-containing layer formed on the conductive oxide layer, and a third silicon-containing layer formed on the other metal-containing layer;

the metal-containing layer and the other metal-containing layer are formed by a same metal-containing film;

the first silicon-containing layer and the third silicon-containing layer are formed by a same silicon-containing material film,

an offset spacer is formed on a side surface of the gate electrode of the other one of the n-channel field effect transistor and the p-channel field effect transistor, and

a width of a lower portion of the offset spacer in the gate length direction is smaller than that of an upper portion of the offset spacer in the gate length direction.

2. The semiconductor device of claim 1 , wherein:

another offset spacer is formed on a side surface of the gate electrode of the one of the n-channel field effect transistor and the p-channel field effect transistor; and

the another offset spacer is a multi-layer film of a first offset film and a second offset film formed outside the first offset film.

3. The semiconductor device of claim 2 , wherein

a part of the offset spacer formed on a side surface of a multi-layer structure of the second silicon-containing layer and the conductive oxide layer is a single-layer film of the second offset film, and

a part of the offset spacer formed on a side surface of a multi-layer structure of the other metal-containing layer and the third silicon-containing layer is a multi-layer film of the first offset film and the second offset film.

4. The semiconductor device of claim 1 , wherein:

a width of the multi-layer structure of the second silicon-containing layer and the conductive oxide layer is larger than that of the multi-layer structure of the other metal-containing layer and the third silicon-containing layer; and

a width of the offset spacer on the side surface of the multi-layer structure of the second silicon-containing layer and the conductive oxide layer is smaller than that of the offset spacer on the side surface of the multi-layer structure of the other metal-containing layer and the third silicon-containing layer.

5. The semiconductor device of claim 1 , wherein at least an upper portion of each of the first silicon-containing layer and the third silicon-containing layer is a silicide layer containing at least one of Ni, Co, Ti, W and Pt.

6. The semiconductor device of claim 1 , wherein the second silicon-containing layer is of a material obtained by doping polysilicon, amorphous silicon or silicon germanium with at least one impurity selected from P (phosphorus), As (arsenic), B (boron), In (indium), N (nitrogen), C (carbon) and F (fluorine).

7. A semiconductor device, comprising an n-channel field effect transistor and a p-channel field effect transistor formed on a semiconductor substrate, wherein:

a gate electrode of one of the n-channel field effect transistor and the p-channel field effect transistor includes a metal-containing layer in contact with a gate insulating film, a conductive oxide layer formed on the metal-containing layer, and a silicon-containing layer formed on the conductive oxide layer;

a gate electrode of the other one of the n-channel field effect transistor and the p-channel field effect transistor includes another silicon-containing layer in contact with a gate insulating film;

the silicon-containing layer and the other silicon-containing layer are formed by a same silicon-containing material film,

an offset spacer is formed on a side surface of the gate electrode of the one of the n-channel field effect transistor and the p-channel field effect transistor, and

a width of a lower portion of the offset spacer in the gate length direction is smaller than that of an upper portion of the offset spacer in the gate length direction.

8. The semiconductor device of claim 7 , wherein an entirety of the other silicon-containing layer is a silicide layer.

9. The semiconductor device of claim 7 , wherein at least an upper portion of each of the silicon-containing layer and the other silicon-containing layer is a silicide layer containing at least one of Ni, Co, Ti, W and Pt.

10. The semiconductor device of claim 7 , wherein:

another offset spacer is formed on a side surface of the gate electrode of the other one of the n-channel field effect transistor and the p-channel field effect transistor;

the another offset spacer is a multi-layer film of a first offset film and a second offset film formed outside the first offset film.

11. The semiconductor device of claim 10 , wherein

a part of the offset spacer formed on a side surface of a multi-layer structure of the metal-containing layer and the conductive oxide layer is a single-layer film of the second offset film, and

a part of the offset spacer formed on a side surface of the silicon-containing layer is a multi-layer film of the first offset film and the second offset film.

12. The semiconductor device of claim 7 , wherein:

a width of the multi-layer structure of the metal-containing layer and the conductive oxide layer is larger than that of the silicon-containing layer; and

a width of the offset spacer on the side surface of the multi-layer structure of the metal-containing layer and the conductive oxide layer is smaller than that of the offset spacer on the side surface of the silicon-containing layer.

13. The semiconductor device of claim 2 , wherein the first offset film and the second offset film are each a silicon oxide film, a silicon nitride film, a silicon carbide film, a silicon oxide nitride film or a silicon oxide carbide film.

14. The semiconductor device of claim 1 , wherein the conductive oxide layer is of an oxide containing at least one of Ir and Ru.

15. The semiconductor device of claim 1 , wherein the metal-containing layer and the other metal-containing layer is a metal film of at least one metal selected from a group consisting of Ni, Pd, Pt, Co, Rh, Ru, Cu, Ag and Au, or a film of a silicide or a carbide of at least one metal selected from the group of metals.

16. The semiconductor device of claim 1 , wherein the metal-containing layer and the other metal-containing layer is a metal film of at least one metal selected from a group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W, or a film of a nitride, a silicide or a carbide of at least one metal selected from the group of metals.

17. The semiconductor device of claim 1 , wherein the gate insulating film is a single-layer film of an insulating film selected from the group consisting of an SiO 2 film, an HfO 2 film, an HfAl x O y film, an HfSi x O y film and a film obtained by adding nitrogen to one of these films, or a multi-layer insulating film including at least one insulating film selected from the group of insulating films.

18. The semiconductor device of claim 10 , wherein the first offset film and the second offset film are each a silicon oxide film, a silicon nitride film, a silicon carbide film, a silicon oxide nitride film or a silicon oxide carbide film.

19. The semiconductor device of claim 7 , wherein the conductive oxide layer is of an oxide containing at least one of Ir and Ru.

20. The semiconductor device of claim 7 , wherein the metal-containing layer is a metal film of at least one metal selected from a group consisting of Ni, Pd, Pt, Co, Rh, Ru, Cu, Ag and Au, or a film of a silicide or a carbide of at least one metal selected from the group of metals.

21. The semiconductor device of claim 7 , wherein the metal-containing layer is a metal film of at least one metal selected from a group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W, or a film of a nitride, a silicide or a carbide of at least one metal selected from the group of metals.

22. The semiconductor device of claim 7 , wherein the gate insulating film is a single-layer film of an insulating film selected from the group consisting of an SiO 2 film, an HfO 2 film, an HfAl x O y film, an HfSi x O y film and a film obtained by adding nitrogen to one of these films, or a multi-layer insulating film including at least one insulating film selected from the group of insulating films.