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 elect ron spectroscopy as a real-time probe of film composition during growt h. Excellent short-range and long-range crystallographic order are ach ieved in films grown to a thickness of several hundred angstroms in th e substrate temperature range of 450 degrees C to 750 degrees C. Moreo ver, the films become more laminar as the growth temperature increases , suggesting that MgO grows homoepitaxially by the step-flow growth me chanism at elevated temperature. The surfaces of films grown at 650 de grees and 750 degrees C are smoother than those obtained by cleaving M gO(001).