INTERFACE PROPERTIES OF THIN OXIDES GROWN ON STRAINED GEXSI1-X LAYER

The electrical and chemical properties of the interfaces of thin oxide s grown on strained GexSi1-x layers are analyzed in detail using capac itance-voltage measurements and Auger electron spectroscopy. It is fou nd that the electrical properties (interface states and fixed oxide ch arges) of the interface depend on various parameters such as oxidation temperature, oxidation time, Ge distribution near the interface, and Ge distribution in the entire epilayer. The Ge distribution at the int erface can be described using concentration-dependent diffusivity of G e in the epilayer. The electrical properties are improved with the inc rease in oxidation temperature, but for a given oxidation temperature, the quality of the interface degrades with the increase in oxidation time. At a very high oxidation temperature the Ge distribution in the entire epilayer is altered due to the high diffusivity of Ge.