Fermi-level oscillation in n -type δ -doped Si : A self-consistent tight-binding approach

We have used the empirical tight-binding method within the antibonding orbital model to compute the self-consistent potential profile and Fermi level position in n -type δ -doped Si . This model describes the six valleys in the Si conduction band adequately. We include exchange-correlation effects under the local density approximation. The comparison of our results to empirical pseudopotential calculations shows very good agreement, while effective mass approximation calculations agree only in the low doping regime. At ultra high densities, an oscillatory behavior of the Fermi-level position as a function of the doping concentration is predicted.