Interface morphology of epitaxial growth of Ge on GaAs and GaAs on Ge by molecular beam epitaxy

Interface morphology of the molecular beam epitaxial growth of Ge on (100) GaAs and of GaAs on (100) Ge at 400°C has been studied by reflection high energy electron diffraction. The (100) Ge surface shows a (2×2) reconstruction pattern. A smooth and planar growth of Ge on GaAs is observed; growth of GaAs on Ge, however, shows a rougher surface with a roughness estimated to be several angstroms which is in agreement with our studies on the Ge-GaAs superlattices using other techniques.