Temperature effects on Ge condensation by thermal oxidation of SiGe-on-insulator structures

Abstract

The Ge depth profile and generation of dislocations associated with oxidation of SiGe-on-insulator (SGOI) substrates are examined from the viewpoint of the temperature dependence. It is found that Ge profiles in SGOI layers after oxidation are strongly dependent on the oxidation temperature. This fact is explained by the competitive process between the accumulation of Ge atoms at the SiGe/thermal oxide interface, determined by the oxidation rate, and Ge diffusion toward substrates during oxidation of SGOI substrates. While the abrupt Ge profile obtained by low-temperature oxidation causes the generation of dislocations, SGOI layers with high Ge content and no dislocations can be achieved by high-temperature oxidation.