TCAD simulation of a double L-shaped gate tunnel field-effect transistor with a covered source-channel

Abstract

In this work, the authors propose and simulate a double L-shaped gate tunnel field-effect transistor (DLG-TFET) with the covered source-channel. The proposed structure improves the ON-state current by increasing the linear tunnelling area and has excellent subthreshold characteristics. The simulation focuses on the performance improvement of the device under different longitudinal gate length Lg, interlayer silicon thickness Tsi, gate and source overlap length Lov, and covered source depth Ls. For optimal parameters, the ON-state current of the proposed DLG-TFET increases up to 3.53 × 10−5 A/μm, and the current switch ratio(Ion/Ioff) is 4.28 × 1011 at room temperature, moreover, a minimum subthreshold swing (SSmin) and an average subthreshold swing (SSave) are as low as 32.2 and 52.9 mV/Dec, respectively. Meanwhile, this work uses mixed device-circuit simulations to predict the performance of the inverter circuit implemented with proposed DLG-TFET.