Patent ID: 7429770

Claim:
A semiconductor device, comprising a CMIS transistor which includes: a p-type MIS transistor including (a1) a first gate insulating film formed over a semiconductor substrate, (a2) a first gate electrode formed over said first gate insulating film, and (a3) a first source region and a first drain region formed in said semiconductor substrate; and an n-type MIS transistor including (b1) a second gate insulating film formed over said semiconductor substrate, (b2) a second gate electrode formed over said second gate insulating film, and (b3) a second source region and a second drain region formed in said semiconductor substrate, wherein said first gate electrode includes a first metal silicide film, and said first metal silicide film is also formed over said first source region, said first drain region, said second source region, and said second drain region, wherein said second gate electrode includes a second metal silicide film which is different from said first metal silicide film, wherein said first metal silicide film has a work function approximate to the valence band of silicon, wherein said second metal silicide film has a work function approximate to the conduction band of silicon, and wherein said first metal silicide film has a sheet resistance smaller than a sheet resistance of said second metal silicide film.