SURFACE CORE LEVELS OF THE 3C SIC(001)3X2 SURFACE - ATOMIC ORIGINS AND SURFACE RECONSTRUCTION

The Si-rich 3 C-SiC(001)3 X 2 surface has been studied by high-resolut ion core-level photoemission. Well resolved Si 2p and C 1s core-level spectra were measured at a temperature of similar to 120 K. Three diff erent Si 2p surface components are clearly identified with binding ene rgy shifts of -0.58+/-0.03, -0.92+/-0.03, and -1.27 +/-0.03 eV, respec tively. The presence of these components and their intensity ratios ar e consistent with a structure model with 2 monolayer (ML) of additiona l Si dimers but incompatible with another model with only 1/3 ML of Si dimers. Assignments have been made of the atomic origins of the Si 2p surface core levels and the line shape of the C is core level 1s disc ussed.