Partial intensity analysis (PIA) for quantitative electron spectroscopy

Abstract

AbstractAn approach is developed to separate the spectral contributions of electrons that have experienced a certain number of inelastic collisions and together constitute the observable lineshape in AES/XPS. The only assumption concerning the emission process that is made in this general approach is that energy losses and deflections occur separately. This means that the method can account for elastic scattering with arbitrary sophistication, while it can also be applied to spectra from samples exhibiting surface roughness or specimens with an arbitrary depth profile and even single crystals where diffraction effects dominate the peak intensities. If the details of the emission process are properly understood, such a so‐called partial intensity analysis may serve to assess the structural characteristics of an unknown specimen. Conversely, if the sample structure is known, it can be employed to assess experimentally the details of the emission process (elastic scattering, roughness, diffraction). At any rate, a partial intensity analysis allows proper background correction of the spectral lineshape to be performed if this is the ultimate aim of analysis. This again holds true without regard to the emission process and is possible without any kind of fitting or ad hoc assumptions. On a very similar basis, a method is derived to gain accurate information about the inelastic transport characteristics from reflection experiments in the case when the other quantities governing the particle transfer are known. The results are general in that the starting point of the method, i.e. the yield equation, in principle also describes the fundamentals of other techniques employing particle–solid interaction.