Thermally grown SiO2layers on Si were bombarded with He+, Ar+, and Xe+ions at energies between 0.5 and 2 keV and subsequently studied by XPS. Chemical shifts of the Si 2pand O 1speaks were not observed as a result of sputtering. Apparently, the oxide is not reduced by ion bombardment. However, the widths of the Si 2pand O 1speaks increase with ion dose and ion energy. A steady state peak width was obtained at each energy for ion doses above 2×1017cm−2. Steady state peak width dependence on ion species and energy is explained by a model based on the mean‐projected ion range. Peak broadening can be explained by an increase in disorder that results from changes in the Si–O bond angle distribution within the ion range.