Mesoscopic scale study of lateral dynamics of Sn-intercalation of the buffer layer on SiC

The dynamics of Sn intercalation of the buffer layer on SiC was investigated with a frozen-in diffusion front using Kelvin Probe Force Microscopy. The technique allows to laterally distinguish between intercalated regions and the pristine buffer layer. Comparing topography features with the surface potential on the mesoscopic scale confirms that surface steps act as transport barriers. The results show a distinct pin hole mechanism for the material flow from terrace to terrace of the vicinal substrate surface. Nucleation and the formation of tin intercalated phase on terraces happen at steps. This results in a mesoscopic growth against the macroscopic diffusion direction.