Patent ID: 8129794

Claim:
A semiconductor device comprising: a first MIS transistor; and a second MIS transistor having a threshold voltage higher than that of the first MIS transistor, wherein the first MIS transistor includes: a first channel region formed in a first active region of a semiconductor substrate; a first gate insulating film made of a high-k insulating film formed on the first channel region in the first active region; and a first gate electrode having a first conductive portion provided on and contacting the first gate insulating film and a second conductive portion formed on the first conductive portion, the second MIS transistor includes: a second channel region formed in a second active region of the semiconductor substrate, and having the same conductivity type as that of the first channel region; a second gate insulating film made of the high-k insulating film formed on the second channel region in the second active region; and a second gate electrode having a third conductive portion provided on and contacting the second gate insulating film, and a fourth conductive portion formed on the third conductive portion, and the third conductive portion has a film thickness smaller than that of the first conductive portion, and has the same composition ratio as that of the first conductive portion.