Relaxed SiGe-on-insulator substrates without thick SiGe buffer layers

Abstract
We have developed a technology for relaxing top SiGe layers with low dislocation density on Si substrates, without using thick SiGe buffer structures. By introducing a thin strained SiGe layer and the internal-oxidation (ITOX) process following the separation-by-implanted-oxygen (SIMOX) process, we have experimentally demonstrated relaxed SiGe-on-insulator (SGOI) substrates with the Ge content of 20%, and it has been realized that their dislocation density is a factor of 20 lower than that of SGOI with SiGe buffer layer.