High-sensitivity Rutherford backscattering spectrometry employing an analyzing magnet and silicon strip detector

摘要

Rutherford backscattering spectrometry (RBS) is an analysis method to quantify reference free the atomic areal density of a thin film, in particular sensitive to those cases where the elements of the film are heavier than the substrate. The ultimate sensitivity is determined by the ratio between the signal intensity from the thin film and the background signal originating from e.g. pulse pile-up events related to the scattering from the substrate atoms or dark noise intrinsic to the detector. We demonstrate that the sensitivity of RBS can be improved by reducing the pulse pile-up and dark noise background through the implementation of a magnet sector and a silicon strip detector as combined double energy dispersive analyzer. A limit-of-detection of 3.10(11) Ru/cm(2) on Si is achieved.