A (2 x 2) reconstruction was obtained on the (00•¯1) surface of 6H-type material by annealing. The structure was denoted, (2 x 2)C, in order to distinguish it from another (2 x 2) periodic structure on the same surface. The reconstruction was characterized by a single Si adatom per unit cell which occupied a 3-fold coordinated hollow site (H3). The results of low-energy electron diffraction analyses were consistent with scanning tunnelling microscopic images which showed a single protrusion per unit cell and a slightly Si-enriched stoichiometry with respect to the bulk SiC; as identified by means of Auger electron spectroscopy. This surface tended to be terminated by an hexagonal stacking. That is, on 60% of the surface the stacking switch which was characteristic of 6H-type material was located below the first bilayer.

Atomic Structure of 6H-SiC(0001)-(2 x 2) J.Bernhardt, A.Seubert, M.Nerding, U.Starke, K.Heinz: Materials Science Forum, 2000, 338-342, 345-8