BISMUTH ON GAAS(110) - CHARACTERIZATION OF GROWTH MODE AND SCHOTTKY-BARRIER FORMATION AT LOW AND ROOM-TEMPERATURE

The Bi/GaAs(110) interface formation and the growth of the Bi overlayer were investigated in situ by Raman spectroscopy, elastic light scattering, and LEED. Additionally, current-voltage (I-V) measurements were carried out. Deposition was performed at substrate temperatures of 90 and 300 K with coverages from the submonolayer range up to 1000 ML. Different growth modes were observed depending on overlayer thickness and deposition temperature: at 300 K Bi clusters are observed at low coverages, followed by two different crystalline phases, whereas at 90 K first an amorphous and then a crystalline phase occurs. The Schottky barrier in the GaAs interface, as determined by Raman scattering, shows an increase in the submonolayer region, followed by strong variations beyond a few ML Bi on n-type GaAs. For coverages above 100 ML the Schottky barriers are 0.61 eV on n-type and 0.85 eV on p-type samples. © 1989.