Effects of multiple elastic and inelastic scattering on energy-resolved contrast in Kikuchi diffraction

Energy-resolved Kikuchi patterns for silicon crystals were measured for 30 keV electrons in a reflection geometry. The amount of contrast seen depends strongly on both the geometry and the energy loss. For geometries where the outgoing trajectory is glancing with the surface, the contrast is maximum for zero loss, decreases with larger energy losses and for energy losses over 1 keV, a reversal of the contrast is observed. For geometries where the incoming beam is glancing, the contrast first gradually increases with energy loss and decreases slowly for losses larger than 100 eV. Under these conditions contrast reversal was not seen. These observations are modelled using the cross sections of the various elastic and inelastic processes involved.