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An Auger depth profile of a layered system is generally evaluated by an interface width. The interface width is expressed as the distance between 16 and 84% (or 84 and 16%) of the intensity change between plateau regions at an interface. However, this method can not be adopted for the analysis of an asymmetric interface profile. J. Fine et al. proposed the Auger depth profiling analysis using the logistic function (LOGIT), including parameters for the interface width and asymmetry, to evaluate an interface profile. Then, We have analyzed the interfaces in Auger depth profiles, for the Ni/Cr multilayer specimen and the GaAs/AlAs superlattice specimen, using curve fitting process by the logistic function. In consequence, the calculated fitted profile curves are in very good agreement with the measured points. Moreover, it has been found that the depth resolution function is expressed by two parameters of the interface-width and the asymmetry. In this report, we recommend that the surface roughening effect and atomic mixing effect are clearly shown using these two parameters. It is shown that the roughening parameter D0 in the logistic function also well correlate with the roughness parameter in the MRI model. |