Patent ID: 8809959

Claim:
A semiconductor device comprising a first MISFET and a second MISFET formed over a semiconductor substrate, the first MISFET comprising: a first gate insulation film including a first lower layer film including silicon, oxygen, and nitrogen formed over the semiconductor substrate, and a first upper layer film including hafnium formed over the first lower layer film; and a first gate electrode formed over the first gate insulation film, and the second MISFET comprising: a second gate insulation film including a second lower layer film including silicon, oxygen, and nitrogen formed over the semiconductor substrate, and a second upper layer film including hafnium formed over the second lower layer film; and a second gate electrode formed over the second gate insulation film, wherein the concentration of hafnium in the second upper layer film is smaller than the concentration of hafnium in the first upper layer film, and wherein the concentration of nitrogen in the second lower layer film is smaller than the concentration of nitrogen in the first lower layer film, wherein both of the first MISFET and the second MISFET are of a p channel type.