The influences of low-energy ion bombardment on surface diffusion have been quantified directly for the first time. Bombardment of germanium diffusing on silicon by noble gas ions between 15 and 65 eV affects the diffusional activation energy and preexponential factor in a strongly temperature-dependent way. Curiously, above about 850 °C the ion-influenced diffusivity actually falls below the thermal value. The results have significant implications for thin film growth by ion-assisted deposition processes.

• Received 28 September 1998

DOI:https://doi.org/10.1103/PhysRevLett.82.1185