The atomic structure of SiC(00•¯1)C surface of the 6H polytype was studied in ultra-high vacuum by scanning tunnelling microscopy, low energy electron diffraction and Auger electron spectroscopy. A number of different reconstructions could be reproducibly prepared in ultra-high vacuum by a combination of annealing a sample with and without silicon flux at 450 to 1400C. One of them was identified as SiC (00•¯1)-(3 x 3) structure. A geometrical model of this reconstruction was proposed. In accordance with that, the unit cell consisted of ten atoms bonding to produce 6 dimers and 3 adatoms. The six- and nine-atom rings surround unoccupied sites of the outermost carbon atoms of the SiC substrate. Each unit cell contains five dangling bonds, three of which were associated with adatoms and were responsible for protrusions in filled-state scanning tunnelling microscopy images. The other two were associated with carbon atoms of the substrate. Furthermore, islands with an unreconstructed SiC (00•¯1)-(1 x 1) surface prepared in ultra-high vacuum were observed with atomic resolution for the first time by means of scanning tunnelling microscopy.

Morphology and Atomic Structure of the SiC(00•¯1)-(3 x 3) Surface Reconstruction. H.E.Hoster, M.A.Kulakov, B.Bullemer: Surface Science, 1997, 382[1-3], L658-65