Transistors having semiconductor-metal composite gate electrodes containing different thickness interfacial dielectrics and methods of making thereof

Abstract

A semiconductor structure, such as a CMOS device, includes a first field effect transistor and a second field effect transistor. The first field effect transistor includes a first composite gate electrode containing a first vertical stack of a p-doped semiconductor gate electrode, a first interfacial dielectric layer, and a first metallic gate electrode. The second field effect transistor includes a second composite gate electrode containing a second vertical stack that includes an n-doped semiconductor gate electrode and a second metallic gate electrode. A second interfacial dielectric layer having a second thickness that is thinner than the first interfacial dielectric layer may, or may not, be present in the second composite gate electrode.