OPTICAL CONSTANTS OF GE NANOLAYERS IN OXIDATION OF SIGE ALLOYS DETERMINED BY ELLIPSOMETRY

Abstract

We investigatd the oxidation behavior of Si_(1-x)Ge_(x)alloys (x=0.005,0.02,0.05,0.15 and 0.25). A new ellipsometric method was used for generating and measuring Ge nanostructures in oxidation of SiGe alloys. The fundamental optical constants of Ge nanolayers in the sample were determined by ellipsometry. The thickness and origin of the Ge bi-nanolayer was found out. A new peak in PL spectra was discovered, which relatd to the Ge bi-nanolayer (thickness: 0.8～1.4nm). Some suitable model and calculating formula can be provided with the UHFR method and quantum confinement analysis to interprete the PL spectrum and the nanostructure mechanism in the oxide.