Abstract
Using in situ electron microscopy, we have measured the structure of during annealing in vacuum. Above , an additional SiC bilayer forms on the surface that changes the polytype from hexagonal () to cubic (). The interaction with surface steps prevents the cubic layer from growing thicker: the new phase does not wet the steps of the underlying substrate. Instead, the cubic layer expands laterally, accelerating step bunching in the surrounding hexagonal regions. During SiC homoepitaxy, this lack of step edge wetting leads to the growth of twins separated by deep grooves.
- Received 11 August 2009
DOI:https://doi.org/10.1103/PhysRevLett.103.256101
©2009 American Physical Society