Stopping power of SiO2 for 0.2-3.0 MeV He ions

The stopping power of SiO2 for 200 keV-3 MeV He ions has been evaluated by Rutherford backscattering (RBS) and a semiempirical stopping power curve is proposed in this energy range. The curve is parameterized using the Andersen and Zieglers formula, allowing for an easy implementation in any simulation program. The estimated accuracy of the present stopping power curve is of the order of 2%. Samples used for the measurements consist of thin SiO2 films grown by wet thermal oxidation of Si(1 0 0) wafers. The thickness of each sample was independently determined by reflectance spectroscopy. The fitting of the experimental RBS spectra was performed using full Monte Carlo calculation of trajectories in the binary collision approximation.