Scanning tunneling microscopy evidence of background contamination-induced 2×1 ordering of the β-SiC(100) c(4×2) surface

Abstract

We use atom-resolved scanning tunneling microscopy (STM) to investigate in the real space, the effects of slight contamination on the β-SiC(100) surface structure. We find that a 2×1 surface ordering is induced by background surface contamination of the c(4×2) surface reconstruction. This results from the disruption of the latter having alternately up- and down-dimer (AUDD) ordering, with all dimers coming at the same height, leading to adsorbate-induced electronic redistribution. This work, which stresses the very high surface sensitivity of the β-SiC(100) c(4×2) surface reconstruction, is especially relevant in achieving high quality “well defined” β-SiC(100) surfaces.