Stacking Transformation from Hexagonal to Cubic SiC Induced by Surface Reconstruction: A Seed for Heterostructure Growth

Abstract

Promoted by Si enrichment during the formation of the reconstructed $(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})R30\ifmmode^\circ\else\textdegree\fi{}$ phase on hexagonal SiC(0001) a cubic stacking sequence develops at the surface. The reconstruction is ultimately resolved to consist of Si adatoms in ${T}_{4}$ sites as found by quantitative LEED crystallography. Prior to the $(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})R30\ifmmode^\circ\else\textdegree\fi{}$ phase evolution mesalike structures with various atomic periodicities are observed by STM. Smoothening of 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.