Patent ID: 8076193

Claim:
A semiconductor device fabrication method comprising: forming a first gate electrode via a first gate insulating film on a P-type semiconductor region formed in a surface portion of a semiconductor substrate, and forming a second gate electrode via a second gate insulating film on an N-type semiconductor region formed in the surface portion of the semiconductor substrate; forming a first insulating film on side surfaces of the first gate electrode and the first gate insulating film, and forming a second insulating film on side surfaces of the second gate electrode and the second gate insulating film; forming a mask having a pattern corresponding to the P-type semiconductor region; etching away the second insulating film by using the mask; removing the mask; and forming a first gate electrode sidewall insulating film on the side surfaces of the first insulating film, and forming a second gate electrode sidewall insulating film on the side surfaces of the second gate electrode and the second gate insulating film, such that an interface insulating film is formed at an interface between the second gate electrode and the second gate insulating film concurrently with the forming of the second gate electrode sidewall insulating film.