(100) orientation-controlled Ge giant-stripes on insulating substrates by rapid-melting growth combined with Si micro-seed technique

Orientation-controlled single-crystal Ge stripes on insulating substrates are desired to achieve high-performance thin-film transistors. The rapidmelting growth process of amorphous Ge has been examined by using polycrystalline Si islands as the growth seed. Rotational growth is found for Ge stripes initiated from (110) and (111) orientations, however, the lateral-growth initiated from the (100) orientation propagates continuously keeping its orientation. Based on these findings, an advanced rapid-melting growth method is developed by combining with the Si(100) micro-seed technique. This enables single-crystal Ge(100) giant-stripes with 400 μm length on insulating substrates. High hole mobility exceeding 1000 cm² V^-1 s^-1 is also demonstrated.