Hybrid-Formation of Ge-on-Insulator Structures on Si Platform by SiGe-Mixing-Triggered Rapid-Melting Growth - A Road to Artificial Crystal

摘要

Single-crystal Ge layers on insulating films (GOI) are desired to achieve advanced 3-dimensional large-scale integrated circuits and high-performance thin-film transistors. We have developed the rapid-melting Ge growth seeded from Si substrates, which achieves chip-size (～cm length) GOI structures with (100), (110), and (111) orientations. Driving force to initiate the lateral growth over insulating films is clarified as the solidification temperature gradient originating from melting-induced Si-Ge mixing. Combination with the artificial Si micro-seed techniques and the rapid melting growth enables the formation of hybrid-orientation GOI arrays, i.e., (100), (110), and (111) stripes, on (100) Si platform. High hole mobility (～1000 cm~2/Vs) in hybrid-orientation GOI is also demonstrated.