Angular distribution of electrons elastically backscattered from amorphousoverlayer systems

Monte Carlo calculations have been performed of the angular distribution of electrons elastically backscattered from amorphous overlayer systems compo sed of thin copper films and semi-infinite silicon substrates. These calcul ations showed that the angular distribution of the elastically reflected in tensity was dependent on film thickness and electron energy. They also show ed 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 f or the contribution from single-scattering events to the angular distributi on of the elastically reflected intensity. Combining this formula and the P i-approximation for multiple scattering, we were able to construct an analy tic formula for the angular distribution of electrons elastically backscatt ered from overlayer systems. Results from this approach were in good agreem ent with those computed using Monte Carlo simulations. (C) 2001 Elsevier Sc ience B.V, All rights reserved.