Atomically controlled molecular beam epitaxy of ferromagnetic silicide Fe₃Si on Ge

Low-temperature (60 °C) molecular beam epitaxy (MBE) of Fe3 Si layers on Ge substrates was investigated. From x-ray diffraction and transmission electron microscopy measurements, it was shown that Fe3 Si layers including the DO3 type were epitaxially grown on Ge(110) and Ge(111), while polycrystal Fe3 Si was formed on Ge(100). Although the Fe3 SiGe (110) interface was slightly rough (∼1 nm), the Fe3 SiGe (111) interface was atomically flat. Such atomically controlled MBE of Fe3 Si on the Ge(111) substrate can be employed to realize Ge channel spin transistors, which can be integrated with Si large-scale integrated circuits.