Mechanism of extraordinary gate-length dependence of quantum dot operation in isoelectronic-trap-assisted tunnel FETs

Abstract

Current characteristics in quantum dot devices based on isoelectronic-trap-assisted tunnel field-effect transistors (TFETs) were investigated employing device simulations. It was clarified that in the case of devices with small gate lengths, the quantum-dot-intermediated tunneling distance is almost identical to the gate length, thereby causing gate-length-dependent current intensity. Furthermore, devices with larger gate lengths probabilistically lack quantum dots in the narrow desirable location, thereby hindering the operation of TFETs as quantum dot devices. This study clarifies an important operating mechanism of quantum dot devices based on TFETs and provides the design guidelines for high-temperature operating quantum bit devices.