Theory of bound states associated withn-type inversion layers on silicon

Abstract

The ground state and two excited states of an electron bound to a charged impurity located at the interface between silicon and silicon dioxide have been investigated. The interface was taken to be parallel to a (001) plane and a static electric field perpendicular to the surface was assumed. Calculations of the electron binding energies as functions of electric field were made for a bare charged impurity with screening by free carriers neglected. In addition, the oscillator strength for electric-dipole transitions was calculated. It was found that the binding energy increases with increasing electric field and approaches that of the corresponding state of a two-dimensional hydrogenlike atom in the limit of infinite electric field.