Central-cell corrections to the theory of ionized-impurity scattering of electrons in silicon

The central-cell correction to the impurity potential for ionized-impurity scattering has been examined in detail. This was then included with the Coulomb and phonon scattering as calculated by Ito and Herring and Vogt for the anisotropic conduction-band valley to determine the theoretical mobility. The central-cell correction was calculated in the spherical approximation with a potential determined empirically from the bound-state energies of the donor, with many-valley effects included. It is shown that the main part of the strain scattering is included as a small component in this empirical potential. The scattering is calculated with Green's-function methods and accounts for most of the observed resistivity, although a discrepancy remains. Similar calculations are reported for the case of Ge.