Elastic electron backscattering from silicon surfaces: effect of charge‐carrier concentration

Abstract

Silicon wafers, p-and n-doped with different free-carrier charge concentrations, were selected as model materials to study a possible influence of charge-carrier concentrations (or electrical conductivity) on measured elastic electron backscattering probabilities and electron inelastic mean free paths determined by elastic peak electron spectroscopy. This research is motivated by contrast changes frequently observed in scanning electron microscopy of semiconductor structures with different types of doping (p-and/or n-) and/or different electrical conductivities. The results show that the measured elastic electron backscattering probabilities and the inelastic mean free paths differ only within experimental uncertainties. They are independent of the type (p-and/or n-) of doping and the free-carrier charge concentration.