Observations of beta-SiC Formation on Reconstructed Si Surfaces

Minute amounts of carbon present on Si surfaces during the UHV anneal necessary to produce the characteristic Si{111}-7 x 7 and Si{001}-2 x 2 ec superlattices, lead to the formation of beta-Sic crystallites on these superlattice surfaces. The presence of these crystals cannot be observed by low energy diffraction (LEED). However, reflection high energy diffraction (RHEED) and Auger spectroscopy are both sensitive enough to detect the corresponding Laue patterns and C-spectra respectively. Energy loss transitions characteristic of the chemical state of Si in beta-Sic are observable with high-resolution Auger spectroscopy.