Applicability of magic angle for angle-resolved X-ray photoelectron spectroscopy of corrugated SiO2/Si surfaces: Monte Carlo calculations

In several earlier works, the “magic angle” has been introduced in overlayer thickness estimation from angle-resolved X-ray photoelectron spectra as a practical tool for suppressing experimental errors induced by surface corrugation. We analyse the applicability of the “magic angle” in Monte Carlo calculations of random as well as non-random corrugated silicon surfaces covered by thin silicon dioxide films, accounting for (a) electron inelastic and elastic scattering events, (b) the shadowing of photoelectrons, and (c) the differences between microscopic and macroscopic electron emission geometry. It is shown that the “magic angle” value varies with the type of surface roughness, overlayer thickness, surface contamination, an uneven overlayer thickness and electron inelastic surface excitations.