DIELECTRIC LOSS FUNCTION OF SI AND SIO2 FROM QUANTITATIVE-ANALYSIS OF REELS SPECTRA

A recently proposed model for quantitative analysis of reflection electron energy-loss spectra (REELS) has been applied to evaluate the dielectric loss function of Si and SiO2 in the 4-100 eV energy range, and to determine inelastic scattering properties for these materials for low-energy electrons (500-10 000 eV). Appropriate trial energy-loss functions (i.e. Im{1/epsilon}) are used and the best loss function is found from the criterion that a satisfactory quantitative agreement is obtained between the simulated and experimental inelastic scattering cross-sections at several primary electron energies. The fact that the energy-loss functions determined in this work agree remarkably well with optical data gives some confidence in the applied procedure. In addition, the effective inelastic mean free paths of the electrons as a function of the primary energy and the path travelled inside the medium have also been determined in terms of the respective energy-loss functions.