Why GeO2 growth on Ge is suppressed and GeO2/Ge stack is much improved in high pressure O2 oxidation?

摘要

This paper reports for the first time a new kinetic model of thermal oxidation of Ge that considers both O-vacancy and atomic O diffusion as a function of O₂ pressure. The model is based on newly obtained results that Ge oxidation is described by kinetics completely different from the Deal-Grove model and that it exhibits anomalous O₂ pressure dependence. Furthermore, new experimental results have been obtained in the oxidation of SiO₂/GeO₂/Ge, GeO₂/SiO₂/Si and GeO₂/SiO₂/Ge stacks. They also strongly support new kinetic model of Ge oxidation. This is critically important for high quality Ge gate stacks, as the Deal-Grove model have played a significant role in Si technology.