The first direct observations of the surface reconstruction of -SiC(100)-c(4 x 2) were obtained by means of high-resolution scanning tunnelling microscopy. Flat surfaces with long-range order were prepared. Individual Si dimers were identified, and formed a centered pseudo-hexagonal pattern which gave a c(4 x 2) array. Further support for the existence of Si dimers was provided by theoretical scanning tunnelling microscopic image calculations. The results suggested a dimer row model with alternating up and down dimers within the row; in a so-called undulating type of arrangement which reduced the surface stress. The -SiC(100) and Si(100)-c(4 x 2) surface reconstructions were therefore very different.

P.Soukiassian, F.Semond, L.Douillard, A.Mayne, G.Dujardin, L.Pizzagalli, C.Joachim: Physical Review Letters, 1997, 78[5], 907-10