Computer Investigations of Features of RHEED Oscillations for GaAs and for Ge

Abstract

During molecular beam epitaxy regular oscillations of the intensity of the specularly reflected beam often occur. The phenomenon of such oscillations is still theoretically explained only partially. For example it is not clear why usually the oscillation phase depends strongly on the glancing angle of the incident beam. However, quite recently interesting results were shown in the literature on the features of RHEED oscillations observed during the growth of Ge layers. The phase of oscillations practically stays constant for a wide range of angles. So in this paper, we show results of RHEED dynamical calculations for Ge. They are presented together with results of calculations for GaAs to make analysis executed more complete. It is concluded that experimental findings for Ge for off-symmetry azimuths can be explained using dynamical diffraction theory employing the proportional model (for which the scattering potential of the layer is determined as the potential of the completed layer multiplied by the coverage).