The glide and lock-in mechanism of Si magic cluster diffusion on the Si(111)-7x7 surface was investigated using a scanning tunneling microscope. The biased long jumps parallel and normal to the direction of the heating current were determined separately and quantitatively. The tendency of Si magic clusters to detach from the corner step edge of a Si lake on the side of the anode and their subsequent attachment to that at the side of the cathode was studied. The biased detachment of Si magic clusters from Si islands near the cathode side was also observed and studied. The driving force of this anisotropic behavior was significantly stronger than that indicated by current theories.

Biased Diffusion of Si Magic Clusters on Si(111) Surface. M.S.Ho, I.S.Hwang, T.T.Tsong: Journal of Applied Physics, 2005, 97[2], 023522 (5pp)