Patent ID: 8395219

Claim:
A semiconductor device comprising a first transistor and a second transistor formed in a semiconductor substrate, the first transistor comprising: a first gate insulating film formed on the semiconductor substrate; and a first gate electrode formed on the first gate insulating film, the second transistor comprising: a second gate insulating film formed on the semiconductor substrate; a cap film formed on the second gate insulating film; and the first gate electrode formed on the cap film, wherein the first gate insulating film includes a first insulating material with a first metal element diffused therein, the cap film includes a second metal element which is different from the first metal element, the second gate insulating film includes a second insulating material, both of the first and second insulating materials include silicon and a third metal element, and the third metal element is different from the first and second metal elements, and the first and second metal elements are not silicon.