Abstract :
In order to test structure models of the c(2 × 2)-reconstruction, angle-integrated valence band spectra at c(2 × 2) and (2 × 1) 3Csingle bondSiC(100) surfaces are reported. The surfaces are characterised by X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED). Two different preparation techniques for the c(2 × 2)-reconstruction are compared, and it is shown that both methods yield the same well-defined ultraviolet photoemission (UPS) spectra. On the (2 × 1)-surface, we find emission from an occupied surface state. On the c(2 × 2)-surface, no unambiguous evidence for a true surface state could be found. However, we find a surface resonance below the valence band maximum. Band bending and work function results for the two reconstructions and the effect of atomic hydrogen on the c(2 × 2)-surface are also reported.
