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 °C), middle (700-800 °C), and high (> 800 °C) temperature regions. Very thin SiO2 layers (< 150 nm) were formed during low (< 680 °C) temperature oxidation. Thus, the Ge fractions at the SiO2/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 SiO2 (> 200 nm) was formed during high (> 800 °C) temperature oxidation. Thus, the oxidation rate was limited by the diffusion process of O in SiO2. 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 SiO2/SiGe interfaces.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry