Surface region of a material under particle bombardment where the chemical state or physical structure is modified by the effects of the bombardment.
Notes: - For silicon bombarded by \(\pu{4 keV}\) \(\ce{O2+}\) at near-normal incidence, after sputtering for a sufficient time to reach a steady state, the surface is converted to stoichiometric \(\ce{SiO2}\) to a depth of around \(\pu{15 nm}\), with lower oxygen concentrations at greater depths. At \(\pu{2 keV}\), this is reduced to \(\pu{7 nm}\), these thicknesses being approximately twice the projected range.
- The observed interface width (depth resolution) in secondary-ion mass spectrometry can be greater or smaller than the altered-layer thickness, depending on the analyte and bombarding-ion species.
Source:
PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1796 (https://doi.org/10.1515/pac-2019-0404)