OPTIMIZATION OF CHARGE-TRANSFER TO THE ACTIVE CHANNEL IN DELTA-DOPED HETEROSTRUCTURES

An accurate theoretical model based on the two-band effective-mass-app roximation that includes nonparabolic, strain, finite temperature, man y-body, and deep donor (DX) center effects is used to investigate the electronic proper-ties of delta-modulation-doped semiconductor heteros tructures with the aim of optimizing the active channel density. Inclu sion of the DX centers in the model leads to the saturation of the ele ctronic density with increasing delta-doping concentration for both st ructures doped on one side and structures doped on both sides of the c hannel. The saturation value in the latter case is almost twice as hig h as in the former. The self-consistent calculations show that by usin g a superlattices of superlattices configuration with an appropriately chosen superlattice barrier one can achieve a 50% increase in the max imum charge transfer compared to conventional heterostructures of simi lar design, without increasing impurity scattering in the channel.