Contribution of slow electrons to the inelastic reflection anisotropy

A study was made of the contribution of low-energy (up to 1 keV) electrons to the anisotropy of inelastic electron scattering from a (111) silicon single crystal in the primary electron energy range 12--50 keV. The experimental data on the anisotropy of inelastic electron scattering were obtained in the form of retardation curves for a silicon single crystal (which made it possible to identify electrons with energy up to 1 keV), dependences of the anisotropy of the inelastic scattering of electrons on the primary electron energy for systems comprising single-crystal silicon and amorphous silicon films, and retardation curves of such systems (the film thickness varied from 20 to 2000 A). A phenomenological model was developed to allow for the contribution of slow electrons to the inelastic electron scattering anisotropy: it was assumed that three groups of electrons contributed to the anisotropy and they were elastically and inelastically reflected electrons, slow electrons excited by the primaries, and slow electrons generated by the return flux of the scattered electrons. This model and the experimental results were used to estimate the contribution of various electrons to the anisotropy. It was found that the slow electrons contributed about half the scattering anisotropy and themore » contributions of the two groups of slow electrons were approximately the same.« less