Impact of Dielectric Material Selection on Electrical Characteristics of High-k/Ge Devices

Abstract

The impact of high-k material selection on the electrical characteristics of high-k/Ge MIS capacitors is investigated. The Y2O3/Ge can maintain good electrical characteristics even after annealing at 600{degree sign}C, while HfO2/Ge seriously degrades. The Ge diffusion into Y2O3 occurs during the annealing, but the characteristics of MIS capacitors do not change even by an intentional doping of Ge into high-k films. The Ge substrate quality is not significantly affected by metal diffusion, neither. These results clearly show that the critical difference between HfO2/Ge and Y2O3/Ge systems is, the ability to form a high quality interface through interface reaction.