The structure of the (v3 x v3)R30º Si-terminated (00•1) surface of 6H-type material was investigated by using grazing-incidence X-ray diffraction under ultra-high vacuum. It was found that a simple adatom structure, with one Si atom per reconstructed unit cell sitting in a T4 site over the top SiC bilayer, was the only one which was compatible with the data. This ruled out other models which involved Si adatoms in H3 sites, Si trimers, C adatoms or Si vacancies, and supported recent theoretical predictions. The predominance of 3 bilayer steps, with an A-type termination of the bulk stacking, was confirmed. It was also shown that varying the preparation conditions changed the density of faulted boundaries in the reconstructed surface, but maintained an unique atomic structure within the (v3 x v3)R30º ordered domains.

(v3 x v3) R30º Reconstruction of the 6H-SiC (0001) Surface - a Simple T4 Si Adatom Structure Solved by Grazing-Incidence X-Ray Diffraction A.Coati, M.Sauvage-Simkin, Y.Garreau, R.Pinchaux, T.Argunova, K.Aïd: Physical Review B, 1999, 59[19], 12224-7