OBSERVATION OF DIFFERENT REFLECTED HIGH-ENERGY ELECTRON-DIFFRACTION PATTERNS DURING ATOMIC LAYER EPITAXY GROWTH OF CDTE EPILAYERS

We present the first RHEED observations during atomic layer epitaxy growth of CdTe on GaAs substrates. The evolution of the RHEED pattern shows that, despite the large lattice mismatch, growth becomes two-dimensional after the deposition of a few monolayers. We observe intensity variations of two RHEED spots under surface resonance conditions and show that this new approach is superior to the observation of the specular spot for the measurement of surface coverages and adsorption kinetics. From the variation of the spot intensities with substrate temperature, we deduce that the Cd and Te surface coverages drop to 0.5 at substrate temperatures higher than 315-degrees-C.