Angular distribution of electrons elastically backscattered from amorphous overlayer systems

Monte Carlo calculations have been performed of the angular distribution of electrons elastically backscattered from amorphous overlayer systems composed of thin copper films and semi-infinite silicon substrates. These calculations showed that the angular distribution of the elastically reflected intensity was dependent on film thickness and electron energy. They also showed that elastically backscattered electrons were due substantially to one, two and three scatterings with single-scattering events contributing about half of the intensity. Based on these findings, we have derived a formula for the contribution from single-scattering events to the angular distribution of the elastically reflected intensity. Combining this formula and the P₁-approximation for multiple scattering, we were able to construct an analytic formula for the angular distribution of electrons elastically backscattered from overlayer systems. Results from this approach were in good agreement with those computed using Monte Carlo simulations.