Depth profiling of multilayer inhomogeneous ultra-thin films with a sub-nanometer resolution

A comprehensive in situ method of non-destructive quantitative chemical phase depth profiling of multilayer multicomponent ultra-thin films on various substrates is proposed, within sub-nanometer accuracy, for depth up to few tens nanometers, based on angle-resolved X-ray photoelectron spectroscopy and photoelectron energy losses spectroscopy. Chemical phase depth profiling of air-oxidized ultra-thin niobium and niobium nitride films has been performed.