Semiconductor device

1. A semiconductor device comprising:

a first MIS transistor; and

a second MIS transistor, wherein:

the first MIS transistor includes:

a first gate insulating film formed on a first active region in a semiconductor substrate, and including a first high-k film made of oxide containing hafnium and silicon;

a first gate electrode including a second metal film formed on the first gate insulating film;

first sidewall spacers formed on side surfaces of the first gate electrode, the first sidewall spacers being insulative; and

a silicon nitride film formed, extending over the side surfaces of the first gate electrode on which the first sidewall spacers are formed and upper surfaces of regions located in the first active region laterally outside the first sidewall spacers,

the second MIS transistor includes:

a second gate insulating film formed on a second active region in the semiconductor substrate, and including a second high-k film made of oxide containing hafnium and silicon;

a second gate electrode including a first metal film formed on the second gate insulating film and a conductive film formed on the first metal film;

second sidewall spacers formed on side surfaces of the second gate electrode, the second sidewall spacers being insulative;

the silicon nitride film formed, extending over the side surfaces of the second gate electrode on which the second sidewall spacers are formed and upper surfaces of regions located in the second active region laterally outside the second sidewall spacers; and

source/drain regions formed in the second active region laterally outside the second sidewall spacers,

the first and second metal films are made of different metal materials,

the silicon nitride film is not formed on any of upper surfaces of the first and second gate electrodes,

the source/drain regions include a silicon mixed crystal layer which is formed in trenches provided in the second active region, and causes first stress in a gate length direction of a channel region in the second active region, and

the silicon nitride film has a thickness smaller than that of the first gate electrode.

2. The semiconductor device of claim 1 , wherein

the first metal film has a thickness smaller than that of the second metal film.

3. The semiconductor device of claim 1 , wherein

the first and second metal films have different work functions.

4. The semiconductor device of claim 1 , wherein

the conductive film is made of the second metal film.

5. The semiconductor device of claim 1 , wherein

the conductive film is made of a silicon film, and

the semiconductor device further comprises a metal silicide film formed on the silicon film.

6. The semiconductor device of claim 1 , wherein

the first and second gate insulating films are made of the same insulating material.

7. The semiconductor device of claim 1 , wherein:

each of the first sidewall spacers is made of a first inner sidewall having an L-shaped cross-section, and

each of the second sidewall spacers is made of a second inner sidewall having an L-shaped cross-section, and the silicon nitride film is formed in contact with surfaces of the first and second inner sidewalls which are bent in an L-shape.

8. The semiconductor device of claim 1 , wherein

the silicon nitride film causes second stress in a gate length direction of a channel region in the first active region.

9. The semiconductor device of claim 8 , wherein:

the first MIS transistor is an n-type MIS transistor, and

the second stress is tensile stress.

10. The semiconductor device of claim 1 , wherein

the second MIS transistor is a p-type MIS transistor,

the silicon mixed crystal layer is made of a SiGe layer, and

the first stress is compressive stress.

11. A semiconductor device comprising:

a first MIS transistor; and

a second MIS transistor, wherein:

the first MIS transistor includes:

a first gate insulating film formed on a first active region in a semiconductor substrate;

a first gate electrode including a second metal film formed on the first gate insulating film;

first sidewall spacers formed on side surfaces of the first gate electrode, the first sidewall spacers being insulative; and

a silicon nitride film formed, extending over the side surfaces of the first gate electrode on which the first sidewall spacers are formed and upper surfaces of regions located in the first active region laterally outside the first sidewall spacers,

the second MIS transistor includes:

a second gate insulating film formed on a second active region in the semiconductor substrate,

a second gate electrode including a first metal film formed on the second gate insulating film and a conductive film formed on the first metal film;

second sidewall spacers formed on side surfaces of the second gate electrode, the second sidewall spacers being insulative; and

the silicon nitride film formed, extending over the side surfaces of the second gate electrode on which the second sidewall spacers are formed and upper surfaces of regions located in the second active region laterally outside the second sidewall spacers,

the first and second metal films are made of different metal materials,

the silicon nitride film is not formed on any of upper surfaces of the first and second gate electrodes,

the conductive film is made of a silicon film,

the semiconductor device further comprises a metal silicide film formed on the silicon film, and

the silicon nitride film has a thickness smaller than that of the first gate electrode.

12. The semiconductor device of claim 11 , wherein

the first metal film has a thickness smaller than that of the second metal film.

13. The semiconductor device of claim 11 , wherein

the first and second metal films have different work functions.

14. The semiconductor device of claim 11 , wherein

the first and second gate insulating films are made of the same insulating material.

15. The semiconductor device of claim 11 , wherein

the first and second gate insulating films are made of different insulating materials.

16. The semiconductor device of claim 11 , wherein:

each of the first sidewall spacers is made of a first inner sidewall having an L-shaped cross-section, and

each of the second sidewall spacers is made of a second inner sidewall having an L-shaped cross-section, and

the silicon nitride film is formed in contact with surfaces of the first and second inner sidewalls which are bent in an L-shape.

17. The semiconductor device of claim 11 , further comprising:

source/drain regions formed in the second active region laterally outside the second sidewall spacers,

wherein the source/drain regions include a SiGe layer which is formed in trenches provided in the second active region.

18. The semiconductor device of claim 11 , wherein

the first and second gate insulating films include a high-k film made of a metal oxide having a relative dielectric constant of 10 or more.

19. A semiconductor device comprising:

a first MIS transistor; and

a second MIS transistor, wherein:

the first MIS transistor includes:

a first gate insulating film formed on a first active region in a semiconductor substrate, and including a first high-k film made of oxide containing hafnium and silicon;

a first gate electrode including a second metal film formed on the first gate insulating film;

first sidewall spacers formed on side surfaces of the first gate electrode, the first sidewall spacers being insulative; and

a silicon nitride film formed, extending over the side surfaces of the first gate electrode on which the first sidewall spacers are formed and upper surfaces of regions located in the first active region laterally outside the first sidewall spacers,

the second MIS transistor includes:

a second gate insulating film formed on a second active region in the semiconductor substrate, and including a second high-k film made of oxide containing hafnium and silicon;

a second gate electrode including a first metal film formed on the second gate insulating film and a conductive film formed on the first metal film;

second sidewall spacers formed on side surfaces of the second gate electrode, the second sidewall spacers being insulative; and

the silicon nitride film formed, extending over the side surfaces of the second gate electrode on which the second sidewall spacers are formed and upper surfaces of regions located in the second active region laterally outside the second sidewall spacers,

the first and second metal films are made of different metal materials,

the silicon nitride film is not formed on any of upper surfaces of the first and second gate electrodes, and

the first metal film is made of titanium nitride.

20. The semiconductor device of claim 19 , wherein

the first metal film has a thickness smaller than that of the second metal film.

21. The semiconductor device of claim 19 , wherein

the first and second metal films have different work functions.

22. The semiconductor device of claim 19 , wherein

the silicon nitride film has a thickness smaller than that of the first gate electrode.

23. The semiconductor device of claim 19 , wherein:

each of the first sidewall spacers is made of a first inner sidewall having an L-shaped cross-section, and

each of the second sidewall spacers is made of a second inner sidewall having an L-shaped cross-section, and

the silicon nitride film is formed in contact with surfaces of the first and second inner sidewalls which are bent in an L-shape.

24. The semiconductor device of claim 19 , further comprising:

source/drain regions formed in the second active region laterally outside the second sidewall spacers,

wherein the source/drain regions include a SiGe layer which is formed in trenches provided in the second active region.

25. A semiconductor device comprising:

a first MIS transistor; and

a second MIS transistor, wherein:

the first MIS transistor includes:

a first gate insulating film formed on a first active region in a semiconductor substrate;

a first gate electrode including a second metal film formed on the first gate insulating film;

first sidewall spacers formed on side surfaces of the first gate electrode, the first sidewall spacers being insulative; and

a silicon nitride film formed, extending over the side surfaces of the first gate electrode on which the first sidewall spacers are formed and upper surfaces of regions located in the first active region laterally outside the first sidewall spacers,

the second MIS transistor includes:

a second gate insulating film formed on a second active region in the semiconductor substrate;

a second gate electrode including a first metal film formed on the second gate insulating film and a conductive film formed on the first metal film;

second sidewall spacers formed on side surfaces of the second gate electrode, the second sidewall spacers being insulative; and

the silicon nitride film formed, extending over the side surfaces of the second gate electrode on which the second sidewall spacers are formed and upper surfaces of regions located in the second active region laterally outside the second sidewall spacers,

the first and second metal films are made of different metal materials,

the silicon nitride film is not formed on any of upper surfaces of the first and second gate electrodes, and

the silicon nitride film causes first stress in a gate length direction of a channel region in the first active region.

26. The semiconductor device of claim 25 , wherein

the first metal film has a thickness smaller than that of the second metal film.

27. The semiconductor device of claim 25 , wherein

the first and second metal films have different work functions.

28. The semiconductor device of claim 25 , wherein

the silicon nitride film has a thickness smaller than that of the first gate electrode.

29. The semiconductor device of claim 25 , wherein

the conductive film is made of the second metal film.

30. The semiconductor device of claim 25 , wherein:

the conductive film is made of a silicon film, and

the semiconductor device further comprises a metal silicide film formed on the silicon film.

31. The semiconductor device of claim 25 , wherein

the first and second gate insulating films are made of the same insulating material.

32. The semiconductor device of claim 25 , wherein

the first and second gate insulating films are made of different insulating materials.

33. The semiconductor device of claim 25 , wherein:

each of the first sidewall spacers is made of a first inner sidewall having an L-shaped cross-section,

each of the second sidewall spacers is made of a second inner sidewall having an L-shaped cross-section, and

the silicon nitride film is formed in contact with surfaces of the first and second inner sidewalls which are bent in an L-shape.

34. The semiconductor device of claim 25 , further comprising:

source/drain regions formed in the second active region laterally outside the second sidewall spacers,

wherein the source/drain regions include a SiGe layer which is formed in trenches provided in the second active region.

35. The semiconductor device of claim 25 , wherein

the first and second gate insulating films include a high-k film made of a metal oxide having a relative dielectric constant of 10 or more.