Quantitative evaluation of sputtering induced surface roughness in depth profiling of polycrystalline multilayers using Auger electron spectroscopy

Abstract Ion sputtering induced roughness during depth profiling of polycrystalline Ni/Cr multilayers using Auger electron spectroscopy (AES) was evaluated by fitting calculated depth profiles to measured ones. The model used for calculation of the depth profile as can be observed upon sputtering accounts for the broadening (‘smearing’) upon AES depth profiling owing to the effects of atomic mixing, surface roughness, escape depth of the Auger electrons, and preferential sputtering. The depth resolution of the measured AES depth profile was calculated directly from the values determined for the fitting parameters in the model. The depth profile recorded from a stationary Ni/Cr multilayered specimen was fitted by assuming, additionally, that the ion sputtering induced roughness increases with the sputter depth, keeping the other fitting parameters (depth independent) equal to those determined for a rotating specimen.