Elastic Backscattering of Ions for Compositional Analysis

Abstract

AbstractBS (elastic backscattering spectrometry, either RBS or EBS) using MeV beams is used to obtain elemental depth profiles of thin films up to ∼10 mm thick. Depth resolution degrades with depth but can be ∼1 nm at the surface. Various ion beams and various beam energies can be selected to obtain the optimal analytical conditions for particular samples.We will briefly mention the use of microbeams since many samples are small or laterally non‐homogeneous. We will also briefly mention the use of ion channelling geometries for characterizing defects in single crystal samples. We should also mention that LEIS and MEIS are both RBS techniques, but they use low energy beams and will not be covered in this article.We treat all the IBA techniques synergistically. The present article considers the details of analysis using a particle detector placed in the backscattering direction. We explicitly distinguish between RBS and EBS, even though in any particular BS spectrum there may be (and often are) both RBS and EBS signals, since there is a philosophical difference of treatment between a signal resulting from a Coulomb interaction and one resulting from an interaction that must be treated quantum mechanically.