Localized states ofp-type inversion layers in semiconductor field-effect transistors

A variational calculation is presented for the electronic configuration of a $p$-type surface accumulation layer of a metal-oxide-semiconductor device. The self-consistent equations show that the criterion for the penetration of a second (light-mass) subband of carriers, after a first (heavy-mass) subband is present depends crucially on the oxide-layer thickness and the transverse mass of the heavy carriers. Agreement with reported experimental results is excellent.