Refined calculations of effective attenuation lengths for SiO2 film thicknesses by x-ray photoelectron spectroscopy

Abstract

Electron effective attenuation lengths (EALs) for Si O2 films on Si are reported that were obtained from Monte Carlo simulations of substrate Si 2 p32 photoelectron transport for x-ray photoelectron spectroscopy (XPS) with Al Kα and Mg Kα x rays and Si O2 films of varying thicknesses. These EALs show a stronger dependence on Si O2 thickness than previous values found from an approximate algorithm. Since recent XPS data for Si O2 can be analyzed satisfactorily with thickness-independent EALs, the results indicate that intrinsic excitations and/or variations of inelastic-scattering probabilities near surfaces and interfaces appear to be significant in quantitative XPS. © 2006 American Institute of Physics.