Monte Carlo simulations of coaxial backscattered electrons in SEM

We simulate the trajectories of backscattered electrons within a SEM of par ticular detection geometry which is adapted to topographic contrast attenua tion and Z atomic number contrast enhancement. The calculations are perform ed choosing the different experimentally possible conditions as regards the primary electron energy, the detector aperture angle and the energy window of the detected electrons. From such simulations, it is possible to deduce the backscattering coefficient and consequently the conditions which optim ize the Z analysis, particularly in order to avoid confusion between Z and topographic contrast. (C) 1999 Elsevier Science B.V. All rights reserved.