Optimization of depth resolution parameters in AES sputter profiling of GaAsrAlAs multilayer structures

Depth resolution, roughness and atomic mixing parameters in sputter depth profiling with AES were studied on GaAsrAlAs multilayers in dependence of the type of sputtering gas Ar, Xe, SF6., the ion energy and the ion incidence angle, using the mixing–roughness–information depth MRI.model for profile quantification and determination of the roughness and the mixing length. Both parameters were found to decrease with decreasing ion energy and increasing incidence angle. For some samples, the surface roughness was additionally measured by atomic force microscopy AFM. after profiling. The lowest mixing length was obtained for 500 eV energy and 808 incidence angle and was 1.4, 0.8 and 0.4 nm for the ions of Ar, Xe and SF6, respectively. The very low mixing length for SF6can be explained by the low impact energy of the atoms sharing the total energy of the ionized molecule. q1999 Elsevier Science B.V. All rights reserved.