Simulation of a quasi-ballistic quantum-barrier field-effect transistor based on GaAs quantum wire

A new constructive solution of field-effect transistor (FET) with a Schottky barrier in a conducting channel has been identified. The FET is a quasi-ballistic quantum-barrier transistor based on a cylindrical undoped GaAs quantum wire in Al$_2$O$_3$ matrix surrounded by a cylindrical metallic gate. A technique for determining the optimal variation of the semiconductor quantum wire diameter along its axis has been developed. The optimal dependence of the nanowire diameter on the spatial coordinate along its axis has been determined providing the possibility of both the elimination of quantum barrier for electrons by the positive gate voltage and the minimization of transistor channel electrical resistance in contrast to a typical FET with a Schottky barrier in its conducting channel. The current-voltage characteristics of the transistor based on GaAs quantum wire with an optimal cross-section have been calculated within the framework of a developed combined physico-mathematical model describing the electron transport in the transistor channel. This model takes into account the nonparabolicity of the semiconductor band structure, the quantum-dimensional effects, and such secondary quantum effects as the collisional broadening and displacement of electron energy levels.