Cmos (complementary metal oxide semiconductor) devices having metal gate nfets and poly-silicon gate pfets

Abstract

A semiconductor structure. The semiconductor structure includes: a first semiconductor region and a second semiconductor region; a first gate dielectric region on the first semiconductor region; a second gate dielectric region on the second semiconductor region, wherein the second semiconductor region includes a first top surface shared by the second semiconductor region and the second gate dielectric region, and wherein the first top surface defines a reference direction perpendicular to the first top surface and pointing from inside to outside of the second semiconductor region; an electrically conductive layer on the first gate dielectric region; a first poly-silicon region on the electrically conductive layer; a second poly-silicon region on the second gate dielectric region; a first hard mask region on the first poly-silicon region; and a second hard mask region on the second poly-silicon region.