M. Dubey et al., GROWTH OF SINGLE-CRYSTAL GE FILMS ON GAAS AND INGAP AND HIGHLY ORIENTED AU FILMS ON GE, Applied physics letters, 64(20), 1994, pp. 2697-2699
Single crystal germanium films were deposited on (100) GaAs and InGaP
substrates, and highly oriented gold films were deposited on the germa
nium films by ultrahigh vacuum E-beam evaporation. They were character
ized 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, a
nd the highly oriented gold film formed a smooth interface with the ge
rmanium 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. Lar
ge grains with one or the other orientation relationship could be dist
inguished in the SEM. TEM micrographs show that the grains have a peri
odic dislocation pattern indicative of heteroepitaxy, and the grain bo
undaries appear to have a low energy. No contamination was detected in
the gold film away from the interface with the germanium, and there w
as significant channeling of the RBS beam when it was normal to the go
ld film.