Analytical modeling of subband quantization and quantum transport in very Low-dimensional dual metal double gate TFET

Abstract

We present a novel and comprehensive quantum analytical modeling of a sub-20 nm Dual Metal Double Gate (DMDG) Tunnel Field Effect Transistor (TFET) for the first time in literature. Owing to structural confinement at sub-20 nm regime, the energy states at channel are quantized and carrier propagation is regulated by quantum transport. We address such quantization aspects (viz. subband quantization, bandgap shifting, tunneling through barrier etc.) and incorporate them in analytical modeling using self-consistent solution of Schrödinger-Poisson's equation. As a result of work function difference at gate, we observe creation of quantum well, followed by a tunneling barrier, along the channel. Energy states in the quantum well are derived from Schrodinger equation, whereas, transmission coefficients are derived for each tunneling barrier. Finally, current density is obtained using ‘Landauer formula for quantum transport’. We methodically study the effects of structural confinement on device performances and observe significant shift from classical counterpart. Moreover, we note that quantization in DMDG TFET can be optimized that will lead to superior device performance. The results are verified with simulation data in each occasion to substantiate analytical models.