Thermal oxidation kinetics of germanium

Thermal oxidation kinetics of Ge was investigated by the 18O tracing study and re-oxidation experiments of the SiO2/GeO2 stacked oxide-layer. The results suggest that Ge oxidation kinetics is completely different from that expected from the Deal-Grove model and that Ge is oxidized by GeO2 on Ge instead of O2 at the interface. This oxidation process forms large amounts of oxygen vacancies in GeO2, which facilitate the diffusion of oxygen atoms in GeO2. This means that oxygen atoms diffuse through GeO2 with an exchange type of process. Based on experimental results, a possible kinetics for Ge oxidation is discussed.