A THEORETICAL-ANALYSIS OF BALLISTIC-ELECTRON-EMISSION MICROSCOPY - BAND-STRUCTURE EFFECTS AND ATTENUATION LENGTHS

Using a quantum mechanical approach, we compute the ballistic electron emission microscopy current distribution in reciprocal space to compa re experimental and theoretical spectroscopic I(V) curves. In the elas tic limit, this formalism is a ''parameter-free'' representation of th e problem. At low voltages, low temperatures, and for thin metallic la yers, the elastic approximation is enough to explain the experiments ( ballistic conditions). At low temperatures, inelastic effects can be t aken into account approximately by introducing an effective electron-e lectron lifetime as an imaginary part in the energy. Ensemble Monte Ca rlo calculations were also performed to obtain ballistic electron emis sion microscopy currents in good agreement with the previous approach.