The effects of low-energy ion bombardment upon surface diffusion were quantified directly here 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:

low temperatures:     D (cm2/s) = 2.0 x 103 exp[-2.44(eV)/kT]

high temperatures:     D (cm2/s) = 3.0 x 10-4 exp[-0.96(eV)/kT]

R.Ditchfield, E.G.Seebauer: Physical Review Letters, 1999, 82[6], 1185-8