MONTE-CARLO SIMULATIONS IN LOW-VOLTAGE SCANNING ELECTRON-MICROSCOPY

The calculation of image contrast of 1-5 keV electrons by Monte Carlo simulations needs extended scattering models. Mott-scattering cross-se ctions are essential for the elastic scattering. A comparison of metho ds using approximations and fitting parameters for Mott cross-sections shows that exact differential cross-sections should be preferred. Ine lastic scattering and energy losses along the electron trajectories ca n be considered by a modified Bethe formula for the stopping power. Ho wever, detailed electron energy-loss spectra (EELS) are needed for the consideration of straggling and the calculation of the energy spectra of backscattered and transmitted electrons, for example.