Electron transport and impact ionization in SiO/sub 2/

Ionizing collisions occurring in low energy (E/spl ges/E/sub gap/) electron transport in SiO/sub 2/ must be considered in floating gate technologies modeling and descriptions of Si/SiO/sub 2/ interface degradation. Underlying theories disagree and result in uncertain predictions of impact ionization. Development of a model for scattering in SiO/sub 2/ of electrons in the energy range /spl sim/5-60 eV that can adequately describe the transition from the electron-phonon interaction to coulomb field scattering has not yet been accomplished. Two considerations which have impeded this effort are: (a) potential asymmetry for single electron scatter by the SiO/sub 2/ unit cell; and (b) uncertainty of appropriate values for the SiO/sub 2/ deformation potential and first Brillouin zone boundary energy.<
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