The effects of low-energy ion bombardment upon surface diffusion were quantified directly for the first time. The bombardment, of Ge diffusing on Si, with noble-gas ions having energies of between 15 and 65eV affected the diffusion activation energy and pre-exponential factor in a strongly temperature-dependent manner (table 7). The ion-influenced diffusivity fell below the thermal value at temperatures above about 850C.

Direct Measurement of Ion-Influenced Surface Diffusion R.Ditchfield, E.G.Seebauer: Physical Review Letters, 1999, 82[6], 1185-8

Table 7

Surface Diffusion Parameters for Ge on Si

(under 65eV Ar+ ion bombardment, 60º off-normal)