High-hole mobility Si1-xGex (0.1 ≤ x ≤ 1) on an insulator formed by advanced solid-phase crystallization

The grain size and hole mobility of polycrystalline Si1-xGex thin films formed on glass by solid-phase crystallization were significantly improved after preparing the amorphous precursors by heating the substrate. By just controlling the deposition temperature of the precursors (50-350 °C) for each SiGe composition, the grain size reached over 2 μm across the whole composition range. Reflecting the enlargement of the grain size, the hole mobility values were improved by approximately one order of magnitude. These values are comparable to those of single-crystal SiGe formed by Ge condensation and are the highest among SiGe on insulators synthesized at low temperature (<900 °C). The SiGe on insulator technology obtained in this study will greatly contribute to the development of SiGe-based electronic and optical devices.