MOLECULAR-BEAM HOMOEPITAXIAL GROWTH OF MGO(001)

We describe homoepitaxial growth and detailed in situ characterization of MgO(001). We have used, for the first time, high-speed Auger electron spectroscopy as a real-time probe of film composition during growth. Excellent short-range and long-range crystallographic order are achieved in films grown to a thickness of several hundred angstroms in the substrate temperature range of 450 degrees C to 750 degrees C. Moreover, the films become more laminar as the growth temperature increases, suggesting that MgO grows homoepitaxially by the step-flow growth mechanism at elevated temperature. The surfaces of films grown at 650 degrees and 750 degrees C are smoother than those obtained by cleaving MgO(001).