Effective Metal Work Function of Pt Gate Electrode in Ge Metal Oxide Semiconductor Device

Abstract

We fabricated Ge and Si metal oxide semiconductor devices with gate stacks and investigated their structural and electrical properties. Postmetallization annealing in ambient reduced the accumulation capacitance more significantly in Si devices than in Ge devices due to the increase in the thickness of a low- interfacial layer in between the film and Si substrate. Ge devices exhibited lower effective work function values for a Pt gate electrode than Si devices owing to the presence of a large number of positively charged dipoles caused by a strong Fermi-level pinning at the Ge surface.