THEORY OF THE ELECTRONIC-PROPERTIES OF DELTA-DOPED LAYERS WITH DX CENTERS IN SEMICONDUCTOR HETEROSTRUCTURES

We attempt to build a flexible and accurate theoretical model for the electronic properties of selectively doped semiconductor heterostructu res based on a two-band k . p effective-mass-approximation Hamiltonian that includes nonparabolicity, stress, piezoelectric, finite-temperat ure, many-body, and DX-center effects. We present quantitative self-co nsistent results for a variety, of delta-modulation-doped semiconducto r heterostructures with the aim of optimizing the electronic density i n the active region as a function of configuration, including [001] an d [111] interfaces for device applications. The presence of DX centers leads to the prediction of saturation of the carrier density with a c haracteristic capacitance discontinuity as the 6-doping concentration is increased. Calculated differential capacitance C-V curves indicate that spatial charge-density inhomogeneities, but not subband depopulat ion, lead to sharp steps in the capacitance as the gate voltage is inc reased.