We demonstrate methodologies to improve the interface characteristics between a germanium (Ge) substrate and high-k gate dielectrics. GeON and SiOx were investigated as passivating layers on a Ge surface. Smaller hysteresis and interface state density (Dit) were obtained using SiOx interface layer and p-type metal oxide semiconductor field effect transistors (MOSFETs) fabricated with a gate stack of Ge/SiO x/HfSiO/WN showed about two times higher effective mobility compared to universal Si/SiO2 MOSFET. Because the formation of GeOx at the interface resulted in higher hysteresis and equivalent oxide thickness, the effective suppression of growth of unstable GeOx by SiO x interface layer contributed to the good device characteristics of the fabricated devices.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)