Confinement-induced InAs/GaSb heterojunction electron-hole bilayer tunneling field-effect transistor

Abstract

Electron-Hole Bilayer Tunneling Field-Effect Transistors are typically based on band-to-band tunneling processes between two layers of opposite charge carriers where tunneling directions and gate-induced electric fields are mostly aligned (so-called line tunneling). However, the presence of intense electric fields associated with the band bending required to trigger interband tunneling, along with strong confinement effects, has made these types of devices to be regarded as theoretically appealing but technologically impracticable. In this work, we propose an InAs/GaSb heterostructure configuration that, although challenging in terms of process flow design and fabrication, could be envisaged for alleviating the electric fields inside the channel, whereas, at the same time, making quantum confinement become the mechanism that closes the broken gap allowing the device to switch between OFF and ON states. The utilization of induced doping prevents the harmful effect of band tails on the device performance. Simulation results lead to extremely steep slope characteristics endorsing its potential interest for ultralow power applications.