Optimization of charge transfer to the active channel in δ-doped heterostructures

Abstract

An accurate theoretical model based on the two-band effective-mass-approximation that includes nonparabolic, strain, finite temperature, many-body, and deep donor (DX) center effects is used to investigate the electronic properties of δ-modulation-doped semiconductor heterostructures with the aim of optimizing the active channel density. Inclusion of the DX centers in the model leads to the saturation of the electronic density with increasing δ-doping concentration for both structures doped on one side and structures doped on both sides of the channel. The saturation value in the latter case is almost twice as high as in the former. The self-consistent calculations show that by using a superlattices of superlattices configuration with an appropriately chosen superlattice barrier one can achieve a 50% increase in the maximum charge transfer compared to conventional heterostructures of similar design, without increasing impurity scattering in the channel.