A MODEL FOR ANALYSIS AND QUANTIFICATION OF ION-SCATTERING SPECTROSCOPY DATA

An improved model has been developed for numerically fitting experimental ion scattering spectroscopy data. This model is a combination of the models described previously by Nelson [J. Vac. Sci. Technol. A 4 (1986) 1567] and Young and Hoflund [Anal. Chem. 60 (1988) 269]. It allows for quantification of the neutralization decay rate, accurate fitting of the different elemental peak shapes, extracting information which is usually difficult to obtain due to poor mass resolution, subtraction of the inelastic background and providing a measure of the composition of the outermost atomic layer. The model has been used to analyze ISS spectra obtained from isotopically pure 24Mg and Mg of natural abundance (79% 24Mg, 10% 25Mg and 11% 26Mg). The factors which influence spectral (mass) resolution have been examined using the model, and calculated results show that both the width of the scattering angle and the energy spread of the primary ion beam significantly affect resolution. © 1990.