The basal surfaces of hexagonal SiC exhibited a large variety of surface reconstructions that develop under a similarly rich variety of sample preparations. A subset of these surface phases, which were investigated in structural detail using scanning tunnelling microscopy and quantitative low-energy electron diffraction, was described and shown to offer the scope to be used for the formation of SiC-based semiconductor devices. The phases discussed were the (3 x 3) and (√3 x √3)R30° reconstructions for the (00•1) surfaces of 4H- and 6H-SiC and the oxygen-uptake-driven (√3 x √3)R30°-SiOx reconstructions of these polytypes for both the (00•1) and the (00•¯1) surface orientations. It was shown that the (3 x 3) reconstruction corresponds to a highly passivated surface that facilitated hexagonal single-crystal growth, while suitable preparation of the (√3 x √3)R30° reconstruction favours a switch to cubic growth and hence to the formation of a heterojunction.

Functional Surface Reconstructions of Hexagonal SiC. K.Heinz, J.Bernhardt, J.Schardt, U.Starke: Journal of Physics - Condensed Matter, 2004, 16[17], S1705-20