Some aspects of Ge epitaxial growth by solid solution

Epitaxial growth of a germanium layer of 0.4–1.1 μm was obtained at 350 °C by the dissolution and transport of an amorphous semiconductor layer through an aluminum film using the Ge (bulk)/Al (evaporated)/Ge (evaporated) structure. Transport and growth were studied by scanning electron microscopy (SEM) and 4He+ backscattering. Channeling measurements indicate that the grown layer is well aligned with the underlying 〈111〉 substrate. Electrical measurements indicate that the grown layer is heavily doped p type. The sputtering cleaning procedure before evaporation is necessary to provide a proper Ge (bulk)/Al interface for nucleation and growth. This effect was verified by measurements of the dissolution rate of Ge in Al film.