APPLICATION OF HEAVY-ION RBS TO COMPOSITIONAL ANALYSIS OF THIN-FILMS

A 8 MeV multicharged carbon or oxygen beam was used for Rutherford Bac kscattering Spectrometry (RBS) compositional analysis. Thin films of C o, Cu, Si, and Ni-Cr of a few nm thickness were deposited on carbon su bstrates by vacuum evaporation or Ar sputtering. The measured results demonstrate that the mass resolution is much better for the heavy-ion RES than for the He-RES analysis. For the compositional analysis, a fi tting function formula is proposed based on a simple model in which th e thin film consists of many islands. The calculated results agree wit h the measured spectra, which show asymmetry of the peaks. Numerical a nalyses using the fitting function give reasonable agreement between t he expected and measured ratios of mass elements in the films. (C) 199 8 Published by Elsevier Science B.V.