High-mobility defect-free ge single-crystals by rapid melting growth on insulating substrates

Single-crystal Ge films on insulating substrates are desired to achieve advanced 3-dimensional large-scale integrated circuits (3D-LSIs) and thin-film transistors (TFTs). We have developed the rapid-melting Ge growth seeded from Si substrates, which achieves giant Ge on insulator (GOI) structures with (100), (110), and (111) orientations. Driving force to initiate the lateral growth is clarified as the solidification temperature gradient originating from melting induced Si-Ge mixing. Combination with the artificial Si micro-seed technique and the rapid melting growth enables the single-crystal defect-free Ge on transparent insulating substrates. High hole mobility exceeding 1000 cm
²
/Vs is also demonstrated.