Attenuation and escape depths of low-energy electron emission

Electron transport and emission is simulated by two Monte Carlo (MC) progra ms. The first version is based on elastic Mott cross sections and inelastic loss functions with full dispersion DeltaE=h omega (q), including electron impact and subsequent cascading processes. Surface effects like surface pl asmons and the quantum mechanical surface transmittivity have been taken in to account too. Especially for dielectric materials like SiO2 and applied e lectric fields a second MC version is developed based on the electron scatt ering with acoustic and optical phonons, intra- and intervalley scattering and impact valence band ionization. A comparison of both versions results i n a good agreement still in the energy region of several eV but a predomina nce of the phonon-based second version is found for very low electron energ ies, e.g., for hot and ballistic electrons in dielectric materials. (C) 200 1 Elsevier Science BY All rights reserved.