The nonlocal dynamics of electrons in pseudomorphic AlGaAs/GaAs/InGaAs heterostructures with double-sided donor-acceptor doping of AlGaAs barriers and additional digital potential barriers of short-period AlAs/GaAs superlattices around the doped regions has been theoretically studied. For the studied heterostructures, the introduction of digital barriers significantly, by 30–40%, increases the electrons drift velocity overshot when they enter the region of a strong field. The effect of localization of hot electrons on the states in AlAs/GaAs superlattices along the edges of the InGaAs quantum well is revealed. It is shown that taking this effect into account significantly increases the electrons drift velocity overshot, bringing it closer to the maximum theoretical limit for the model used – the drift velocity overshot in the undoped InGaAs bulk material.

The processes of nonlocal electron heating in transistor heterostructures based on gallium nitride and gallium arsenide were compared. It has been shown that, in the case of GaAs double doped pseudomorphic heterostructures, the real space transfer of electrons significantly reduces their drift velocity overshot in the region of a strong field as compared with pure bulk GaAs, while in GaN-based heterostructures the decrease in the drift velocity overshot does not exceed 30% in the studied cases. Keywords: Real space transfer, field-effect transistor, gain factor

The nonlocal dynamics of electrons in pseudomorphic AlGaAs/GaAs/InGaAs heterostructures with double-sided donor-acceptor doping of AlGaAs barriers and additional digital potential barriers of short-period AlAs/GaAs superlattices around the doped regions has been theoretically studied. For the studied heterostructures, the introduction of digital barriers significantly, by 30-40%, increases the electrons drift velocity overshot when they enter the region of a strong field. The effect of localization of hot electrons on the states in AlAs/GaAs superlattices along the edges of the InGaAs quantum well is revealed. It is shown that taking this effect into account significantly increases the electrons drift velocity overshot, bringing it closer to the maximum theoretical limit for the model used --- the drift velocity overshot in the undoped InGaAs bulk material. Keywords: potential barriers, digital barriers, heterostructures, electrons drift velocity overshot.

We report on the results of investigations of the millimeter-wave field-effect transistors with a 0.14‑μm T-shaped gate with pseudomorphic Al0.3Ga0.7As–In0.22Ga0.78As–Al0.3Ga0.7As heterostructures with additional potential barriers based on a two-sided donor–acceptor channel doping. At a frequency of 40 GHz in a wide gate voltage range, the maximum stable gain of more than 15 dB has been obtained. The maximum oscillation frequency of the device is about 250 GHz, the open-channel specific current density is about 0.7 A/mm, and the gate–drain breakdown voltage is 22–31 V for different versions.