A model study of field-dependent dynamical screening due to mobile electrons in submicron semiconductor devices

Abstract

A previously obtained generalised field-dependent screening function involving one-electron Wigner distributions and spectral functions is studied under various model approximations. The field dependence of the screening arises from the action of a (constant) electric field within duration of a collision process (estimated from the uncertainty relations) and has the effect of reducing the screening efficiency. This field-induced descreening effect is studied analytically and numerically for a range of electric field strengths and electron temperatures and densities in both three- and two-dimensional non-degenerate electron assemblies. The model assumed allows the influences of displaced Maxwellian distribution functions and finite electron quasiparticle lifetimes to be considered.