Oxidation of SiGe/SOI (Ge fraction: 0-50%) structures was investigated in a wide temperature range. Different oxidation features were observed for samples oxidized in low (<680 degrees C) middle (700-800 degrees C), and high (>800 degrees C) temperature regions. Very thin SiO(2) layers (<150 nm) were formed during low (<680 degrees C) temperature oxidation. Thus, the Ge fractions at the SiO(2)/SiGe interfaces were almost the same as the initial Ge fractions (<50%). Therefore, the initial Ge fraction dependent enhanced oxidation was observed. On the other hand, very thick SiO(2) (>200 nm) was formed during high (>800 degrees C) temperature oxidation. Thus, the oxidation rate was limited by the diffusion process of O in SiO(2). Therefore, the oxidation rate did not depend on the Ge fraction. At middle temperatures, the oxidation rate does not depend on the temperature for samples with high initial Ge fractions (>20%). This is due to that increase in oxidation rate by increasing temperature was cancelled by the retardation of oxidation due to high Ge fractions (>50%) piled-up at the SiO(2)/SiGe interfaces. (c) 2008 Elsevier B.V. All rights reserved.