OXIDE THIN-FILMS FORMED DURING ROTATIONAL AES SPUTTER DEPTH PROFILINGOF NI CR MULTILAYERS USING OXYGEN IONS/

Ni/Cr multilayers composed of 16 alternating Ni and Cr layers with a s ingle-layer thickness of 30 nm on a smooth silicon substrate were AES sputter depth profiled using rastered 6 keV O-2(+) ions. The formation of Ni and Cr oxide thin films was investigated on rotated samples in dependence on the incidence angle of O-2(+) ions in the range between 33 degrees and 77 degrees, The surface concentration of oxygen and the thickness of the oxide thin film decreased with the angle increase, T he quasi-amorphous oxide film with a thickness of a few nanometers, wh ich can diminish the topographical effects, was found only on the samp les that were ion sputtered at lower angles. However, on the rotated s amples depth profiled at grazing incidence angles only the residue of an oxide thin film was found and the improvement of depth resolution i s attributed to the reduction of the other ion-beam-angle-dependent ef fects.