Using complementary surface analysis techniques, a study was made of Ge growth on distinct SiC(00•1) reconstructions, and complex mechanisms occurring by thermal activation were elucidated. Two Si-rich reconstructions, (3 x 3) and (√3 x √3)R30°(√3), and one C-rich, (6√3 x 6√3)R30°(6√3), were considered; upon which Ge was found to grow in Stranski–Krastanov and Volmer–Weber modes, respectively. The best Ge-wetting layer was favoured on the √3 (less Si-rich) because closest to a perfect truncated SiC(00•1) termination. At sufficiently high temperatures, the Ge-wetting layer was organized into the form of a (4 x 4)Ge reconstruction for which a first atomic model was proposed that was based upon the 3 x 3 structure. Annealing Ge on the (3 x 3) and 6√3 surfaces provoked spectacular successive 2D/3D and unusual 3D/2D transitions; not only of Ge but also of Si and C, respectively, coming from the surface initial richness. In both cases, a phase separation was observed either in the 2D or 3D structures, which was unexpected for the Ge/Si binary system and but usual for the Ge/C one. In the case of Ge on 6√3, a special 2D heterostructure graphite/Ge/SiC was achieved at the atomic level. This acted as a Schottky barrier.

Original Ge-Induced Phenomena on Various SiC(0001) Reconstructions. K.Aït-Mansour, D.Dentel, L.Kubler, M.Diani, M.Derivaz, J.L.Bischoff: Journal of Physics D, 2007, 40[20], 6225-41