Double scattering in RBS analysis of PtSi thin films on Si

We present an analytical model for calculation of double scattering in RBS spectra. We show that, in grazing angle of incidence or detection, events with small scattering angle must be taken into account, as long as they lead to paths that are significantly different from the corresponding single scattering event. The effect of lateral spread due to multiple scattering is also taken into account, but in most cases it is not important. We apply the model to thin PtSi films on Si. Excellent results are obtained, except for ultra-thin films measured at extremely grazing angle of incidence, where the analytical model breaks down.