High-hole-mobility single-crystalline ge thin films formed on insulating substrates by SiGe mixing-triggered directional melting growth

The development of high-carrier-mobility Ge-channel thin-film transistors (TFTs) is desired to realize advanced system-in-displays. To achieve the development of single-crystalline Ge films on insulating substrates, we have developed the directional melting growth process of amorphous Ge by using polycrystalline Si islands as growth seeds. Defect-free single-crystalline Ge stripes of 400 mm length are realized, and high-holemobilities of more than 1000 cm2 V^-1 s^-1 are demonstrated in the entire lateral growth region. This method opens up the possibility of fabricating high-speed Ge-channel TFTs for system-in-displays.