Absolute differential yields of condensed rare gases sputtered by keV ions

Abstract

Measurements have been made of the total yield and sputtered particle time-of-flight spectra for the sputtering of solid argon, krypton, and xenon films by 33 keV Ne +, Ar +, Kr +, and Xe +. A careful extrapolation for low energy (long flight-time) particles was made and the resulting time-of-flight spectra were normalized to the experimentally determined total yield, giving absolute yields that are differential in the ejected atom energy. The shape and magnitude of these absolute energy spectra were then compared with earlier experiments and models for sputtering. For the high energy end of the energy spectra the absolute yields are smaller than that predicted from collision cascade theory using the standard parameterization even when the total yields greatly exceed the cascade result. Also it is found from the low energy spectra that, for any ejection model, planar binding is not justified even for the lowest yield case studied here.