Fabrication of high Ge content SiGe layer on Si by Ge condensation technique

It is known that Ge condensation is achieved by thermal oxidation of the SiGe layer whereby Si oxidizes faster as compared to Ge, and the Ge atoms are rejected from the oxide into the SiGe layer below. As the Ge diffusion and accumulation varies with gas flow and temperature, detailed investigations are carried out and process conditions are optimized in this work. The accumulation and diffusion mechanism is found to be dependent on the thermal environment. Further to that, SiGe layers with high Ge content with proper interface is also achieved for the first time and presented in this article. SiGe on bulk Si with 30% and above 50% Ge content are fabricated using this technique for the first time