AUGER IN-DEPTH PROFILING OF MO-SI MULTILAYERS

Auger in-depth profiles were measured on a Mo-Si multilayer structure, consisting of 45 periods of 3.3 nm molybdenum and 3.6 nm silicon laye rs, by means of Ar ion bombardment with rotated specimen and a glancin g incidence ion beam probe. The relative sputtering yield of Si and Mo is determined in the ranges of 2-6 keV ion energy and 80-degrees-87-d egrees incidence angle with respect to the surface normal. It is shown that the depth resolution depends strongly on the ion energy. The dep th resolution changes immediately when the ion energy is changed. This observation is explained by the fact that the depth resolution in our experiment is limited by ion mixing and not by surface roughening. At tempts to determine the initial structure from the measured profile th rough application of Liau's model on ion sputtering were not completel y successful.