GROWTH OF SINGLE-CRYSTAL GE FILMS ON GAAS AND INGAP AND HIGHLY ORIENTED AU FILMS ON GE

Single crystal germanium films were deposited on (100) GaAs and InGaP substrates, and highly oriented gold films were deposited on the germanium films by ultrahigh vacuum E-beam evaporation. They were characterized by double crystal x-ray diffraction (DXRD), transmission electron microscopy (TEM), Rutherford backscattering spectroscopy (RBS), Auger electron spectroscopy (AES), and scanning electron microscopy (SEM). The germanium film grew epitaxially with a smooth, abrupt interface, and the highly oriented gold film formed a smooth interface with the germanium and had a (100)Au parallel-to (100)Ge and (001)Au parallel-to [011]Ge or [001]Au parallel-to [0-1 1]Ge orientation relationship. Large grains with one or the other orientation relationship could be distinguished in the SEM. TEM micrographs show that the grains have a periodic dislocation pattern indicative of heteroepitaxy, and the grain boundaries appear to have a low energy. No contamination was detected in the gold film away from the interface with the germanium, and there was significant channeling of the RBS beam when it was normal to the gold film.