Calibration of the high-doping induced ballistic band-tails tunneling current with In0.53Ga0.47As Esaki diodes

I. Introduction The growing demand for power efficient devices has accelerated the research into the use of the tunnel field-effect transistor (TFET) in future ultra-low power applications because of its promising potential for sub-60 mV/dec subthreshold swing achieved through quantum mechanical band-to-band tunneling (BTBT) [1]-[3]. Unfortunately, a significant gap between theoretical predictions and experiments remains to be bridged [2]. Considerable efforts are being made to develop models for some of the main causes of suboptimal TFET performance such as trap-assisted tunneling (TAT) [4], [5], phonon-assisted tunneling (PAT) [6], and Auger generated leakage currents [7]. However, aside from qualitative analyses [8] and purely predictive work on the device impact of tunneling transitions involving high-doping induced band-tails states in InSb nanowire TFETs [9] and 2D-TFETs [10], no attempts have been made to calibrate these contributions. This work aims to fill this gap by developing and calibrating an approximate ballistic semi-classical (SC) model for high-doping induced band-tails using the experimental I-V data of In0.53Ga0.47As p-i-n Esaki diodes [11]. The hypothesis is posited that the mismatch between measurement and simulation in the negative differential resistance regime (see Fig. 1), which cannot be explained by SC TAT models, is caused by ballistic band-tails tunneling. The calibration thus gives an upper limit to the band-tails current. Lastly, the impact of band-tails on the performance of a p-n-i-n TFET is investigated.