AUGER-ELECTRON SPECTROSCOPY DEPTH PROFILING OF METAL/OXIDE MULTILAYER STRUCTURES

In order to study the different influence of crystalline and amorphous structures on depth resolution, DELTA(z) and its dependence on the sputtered depth z a new multilayer structure composed of chromium, nickel, NiO and Cr2O3 layers with a total thickness of about 475 nm was sputter deposited onto a smooth silicon substrate. Auger electron spectroscopy depth profiles of these samples obtained with 3 keV Ar+ ion sputtering at two different ion beam incidence angles (36-degrees and 73-degrees) were compared with the corresponding profiles of Cr/Ni multilayers with about the same single layer thicknesses. The results show the beneficial influence of an amorphous oxide sandwich layer on DELTA(z): after sputtering through the oxide layer, the depth resolution at the oxide-metal interface was always improved with respect to the previous metal oxide interface at lower depth. The observed effect is explained by reduction of the sputtering induced surface roughness during sputtering through the amorphous oxide layer.