Atomically controlled hetero-epitaxy of Fe3Si/SiGe for spintronics application

Molecular beam epitaxy of the ferromagnetic silicide Fe3Si on Ge and Si substrates was investigated in a wide temperature range (60-400 deg. C). Epitaxial growth of Fe3Si layers was achieved on Ge (110), Ge (111), and Si (111) substrates. Especially, very low value (2.2%) of the minimum scattering yield in RBS measurements was obtained from Fe3Si layers, which were grown on Ge (111) at low temperature (60-130 deg. C) under the stoichiometric condition (Fe:Si = 3:1). Transmission electron microscopy measurements confirmed the formation of DO3-type Fe3Si and atomically flat interface between Fe3Si and Ge (111). In addition, thermal stability of Fe3Si was guaranteed up to 300 deg. C. Such high quality Fe3Si on Ge (111) substrates can be employed to realize Ge channel spin transistors, which can be integrated with Si large-scale integrated circuits