Patent ID: 7391085

Claim:
A semiconductor device comprising: a semiconductor substrate; an nMISFET formed on the semiconductor substrate, the nMISFET including a first dielectric formed on the semiconductor substrate and a first metal gate electrode formed on the first dielectric; and a pMISFET formed on the semiconductor substrate, the pMISFET including a second dielectric formed on the semiconductor substrate and a second metal gate electrode formed on the second dielectric and made of the same material as that of the first metal gate electrode, at least a portion of the second dielectric facing the second metal gate electrode being made of an insulating material different from that of at least a portion of the first dielectric facing the first metal gate electrode, wherein a relation: (χ B−χA )×( dA+dB )≧3.9 is satisfied by electronegativity (χA) and an atomic radius (dA, a unit thereof is Å) of a metal element constituting the first metal gate electrode and the second metal gate electrode and by electronegativity (χB) and an atomic radius (dB) of an element having the highest binding energy to combine with the metal element constituting the second metal gate electrode among elements constituting the portion of the second dielectric of the pMISFET facing the second metal gate electrode.