Fabrication of GeSn-On-Insulator (GSOI) to enable monolithic 3D co-integration of logic and photonics

In this work, we demonstrate the low temperature fabrication of high quality GeSn-On-Insulator (GSOI) which forms the crucial module for monolithic 3DIC. The use of GeSn and Ge overcomes many challenges of monolithic 3D integration, including the need for Si-compatible high-mobility and direct gap materials. Furthermore, we introduce excellent passivation of the semiconductor/buried oxide (BOX) interface which is crucial to the high performance of devices on the stacked layers.