SiGe-on-insulator material fabrication by oxygen implantation into SiGe/Si heterostructure and novel two-step annealing

摘要

Relaxed SiGe-on-insulator (SGOI) is an attractive material to fabricate strained Si structures. Separation-by-implantation-of-oxygen (SIMOX) is a competing method to synthesize SGOI materials. In this work, pseudomorphic SiGe grown directly on Si substrate without any buffer layer SiGe/Si were implanted with 3 x 10~(17) cm~(-2) oxygen ions at 60 kV followed by thermal treatment. Our results show that the sample structure strongly depends on the thermal history. Ge diffusions mainly occur at the beginning stage of the high temperature process. Oxygen segregation and Ge diffusion during the annealing process were investigated using Rutherford backscattering spectroscopy/channeling, high-resolution X-ray diffraction, and high-resolution transmission electron microscopy. We introduce a novel two-step annealing process to reduce Ge loss during the high temperature annealing. Sharp interfaces and good crystal quality SGOI structure was obtained. Our results indicate that the SIMOX process for silicon-on-insulator (SOI) fabrication can be adopted to produce SGOI.