Stacking transformation from hexagonal to cubic SiC induced by surface reconstruction: A seed for heterostructure growth

Promoted by Si enrichment during the formation of the reconstructed (root 3 x root 3)R30 degrees phase on hexagonal SiC(0001) a cubic stacking sequenc e develops at the surface. The reconstruction is ultimately resolved to con sist of Si adatoms in T-4 sites as found by quantitative LEED crystallograp hy. Prior to the (root 3 x root 3)R30 degrees phase evolution mesalike stru ctures with various atomic periodicities are observed by STM. Smoothening o f this rough and Si enriched state provides the material for the formation of the modified stacking sequence which could serve as seed for preparation of SiC polytype heterostructures.