Two-Stream Model of Monoenergetic Electron-Beam Backscattering: Application to Problems of the Diagnostics of Thin-Film Structures

Abstract

The energy spectra of electrons reflected from individual layers located inside a multilayer thin-film target are calculated as applied to problems of the backscattered electron spectroscopy method (BESM). The structure of analytical expressions describing the distribution of the electron-backscattering coefficient over the sample depth is refined. A formula for the two-dimensional polar-angle distribution of backscattered electrons after their exit from a thin-film target with a given thickness is obtained. An algorithm for calculations required to construct the energy distributions of backscattered electrons is developed for a given angular position of the input diaphragm of an analyzer spectrometer. This makes it possible to bring our calculations closer to the actual conditions for recording backscattered electrons. The results of comprehensive verification of the obtained relations based on comparing our model calculations of the energy distributions of backscattered electrons with the experimental spectra of free films, bulk samples, and a multilayer thin-film sample on a massive substrate are given.