Epitaxial growth of Sb-doped Ge layers on ferromagnetic Fe3Si for vertical semiconductor spintronic devices

Abstract

By combining solid phase epitaxy and molecular beam epitaxy with Sb doping, we can form n-type Ge layers on one of the ferromagnetic Heusler alloys, Fe3Si. Two-dimensional epitaxial growth of the Sb-doped Ge layers can be achieved on the Si-terminated Fe3Si surface at 175 ◦C. Electrical properties of the Au-Ti/Sb-doped Ge/Fe3Si/p-Ge/Al vertical devices indicate that the Sb-doped Ge layer is an n-type semiconductor. We also show a high-quality CoFe/n-Ge/Fe3Si trilayer structure for vertical semiconductor spintronic devices.