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

Abstract

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 un doped GaAs quantum wire in Al2O3 matrix surrounded by a cylindrical metallic gate. A technique for determ in ing the optimal variation of the semiconductor quantum wire diam eter along its axis has been developed. The optimal dependence of the nanowire diam eter 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 quan tum 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 displacem ent of electron energy levels.