Giant Ge-on-Insulator Formation by Si–Ge Mixing-Triggered Liquid-Phase Epitaxy

Abstract

Formation of giant single-crystalline Ge-on-insulator (GOI) with 400 µm length is demonstrated by using seeding lateral liquid-phase epitaxy (L-LPE). High quality (100), (110), and (111) oriented single-crystals are obtained on Si substrates covered with SiO2. A mechanism based on the solidification temperature gradient due to Si–Ge mixing and the thermal gradient due to latent heat at the growth front is proposed. An additional experiment on quartz substrates well supports the importance of Si–Ge mixing as a trigger for giant L-LPE of Ge. This process opens up the possibility of Ge-based fully-depleted field-effect transistors with high electron and hole mobilities.