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

Highlights: • High-quality polycrystalline SiGe thin films are formed using simple solid-phase crystallization process. • Just controlling the deposition temperature of the SiGe precursor dramatically improves the grain size. • The SiGe layers exhibit the highest hole mobilities among SiGe on insulators synthesized at low temperature. The grain size and hole mobility of polycrystalline Si_1-xGe_x 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.