A mechanism was proposed in order to describe previous measurements of surface diffusion, in the Ge/Si(111) system, under low-energy ion bombardment. It was shown that direct ion-induced motion of diffusing atoms (supposed to be important in ion beam-assisted deposition) could not account for these observations. The results were instead explained in terms of processes in which the ions created long-lived surface vacancies or spatially extended defects that healed continuously during bombardment. These concepts rationalized several previously-unexplained aspects of the experimental data; including the appearance of ion effects at very low ion fluxes, a simple Arrhenius behavior of the diffusivity, the magnitudes of the observed energy thresholds and the ion-induced inhibition of diffusion at high temperatures.

Semiconductor Surface Diffusion: Effects of Low-Energy Ion Bombardment. R.Ditchfield, E.G.Seebauer: Physical Review B, 2001, 63[12], 125317 (9pp)