PREPARATION AND CHARACTERIZATION OF CARBON-TERMINATED BETA-SIC(001) SURFACES

Carbon-terminated surfaces have been formed on the initially Si-terminated beta-SiC(001)-(2 X 1) surface by exposure to C2H4 at 800-degrees-C-1100-degrees-C. The structure of these surfaces (both as formed and after atomic-H adsorption) has been investigated using Auger and electron-energy-loss spectroscopies, low-energy electron diffraction, and electron-stimulated desorption of H+. A model is proposed for the c(2 X 2) ordered C monolayer consisting of sp3 single-bonded C-C units with each C bridging two nearest-neighbor Si atoms. These species exhibit a high degree of thermal stability, and the single dangling bond remaining on each C is an active site for the thermally reversible adsorption of atomic H. This c(2 X 2) surface is shown to be essentially the same as that formed by thermal desorption of Si from the (2 X 1) surface but is more uniform and well ordered.