Monte Carlo Simulation of Electrons Backscattered from Surface Carbon Films

We have computed, by a Monte Carlo code, the backscattering coefficient of low-medium energy electron beams (from 250 eV to 10,000 eV) impinging on carbon films deposited on two different substrates (Al and Cu). Investigating the behaviour of the backscattering coefficient as a function of the primary energy for various surface film thicknesses, we have found an interesting property, i.e. the appearance of relative maxima of absorption (and relative minima of backscattering). A characteristic of the relative minima is that their position shifts towards higher energies, while the peaks are broadening, as the film thickness increases. The trend presented can be used as a way to measure the carbon film thickness by a set of measures of the backscattering coefficien