High Sn-Content GeSn on Insulator Grown By Rapid Melting Growth

Abstract

GeSn is an attractive semiconductor for group IV photonics and microelectronics due to its special energy band structure and the compatibility with complementary metal oxide semiconductor (CMOS) processes. Unfortunately, epitaxial growth of GeSn is a difficult work. Recently, non-equilibrium grown GeSn at low temperature is an effective technology to grow high Sn-content GeSn on Ge or Si substrate by suppress segregation of Sn. However, because of the larger lattice of GeSn than Ge and Si, high crystal quality, high Sn-content, and strain relaxation are paradox in GeSn film grown on Ge or Si substrate. It is a great challenge to grow tensile strained defect-free high Sn-content GeSn. In this work, tensile strained defect-free high Sn-content GeSn on insulator (GSOI) was laterally grown on an insulator using rapid melting growth. The gradient of Sn-content was created along the GeSn stripes by growing process. The Sn-content distribution is in good agreement with calculated results from the Scheil equation. The Sn-contents at the end of GSOI are depend on the length of the GSOI stripes. The highest Sn-content of the GSOI is increase to 14%, which is high enough to transform the GeSn to a direct bandgap material. No dislocation or stacking fault was observed in TEM image, which indicated the high-crystal quality of the GSOI. Metal-semiconductor-metal photodetectors and P-channel MOSFETs were fabricated on this GSOIs. The optical and electrical characteristics of the GSOIs were studied.