By using density-functional theory together with scanning tunnelling microscopy, it was demonstrated that a thin metallic film on a semiconductor surface may open an efficient and hitherto unexpected diffusion channel for lateral adatom transport: adatoms may prefer diffusion within the metallic layer to that on top of the surface. Recent experiments were interpreted on the basis of this concept. It was explained why and when In acted as a surfactant on GaN surfaces, why Ga acted as an auto-surfactant and how this mechanism could be used to optimize group-III nitride growth.

Adatom Kinetics On and Below the Surface - the Existence of a New Diffusion Channel. J.Neugebauer, T.K.Zywietz, M.Scheffler, J.E.Northrup, H.Chen, R.M.Feenstra: Physical Review Letters, 2003, 90[5], 056101 (4pp)