Depth of origin of sputtered atoms

Estimates are given for the distribution of the depth of origin of sputtered atoms in the low-fluence limit, as well as the corresponding distribution of atoms sputtered into a given energy interval. The former distribution is well described by an exponential profile, with the characteristic depth being consistent with previous results. The latter distribution is characterized by an energy-dependent depth scale and a shape that varies from exponential at low sputtered-atom energies to inverse-power form at higher energies.