Comment on “Optimization of a Pocketed Dual-Metal-Gate TFET by Means of TCAD Simulations Accounting for Quantization-Induced Bandgap Widening”

Abstract

In this comment, we assess the validity of the simulation approach implemented by Beneventi et al. to account for the effects of subband discretization of conduction and valence bands in pocketed dual-metal-gate (DMG) tunnel field-effect transistors (TFETs). To do so, the authors develop a technique compatible with TCAD simulations that allows them to optimize the so far proposed semiclassical DMG-TFET configuration in terms of performance. However, we herein demonstrate analytically that their proposed technique results in increased band-to-band tunneling (BTBT) distances that notably deviate from the actual ones. This discrepancy is expected to entail a significant impact on the current levels of the device given the exponential dependence of BTBT processes on the thickness of the forbidden barrier.