Design Optimization of Double-Gate Isosceles Trapezoid Tunnel Field-Effect Transistor (DGIT-TFET)

Micromachines (Basel). 2019 Mar 30;10(4):229. doi: 10.3390/mi10040229.

Abstract

Recently, tunnel field-effect transistors (TFETs) have been regarded as next-generation ultra-low-power semi-conductor devices. To commercialize the TFETs, however, it is necessary to improve an on-state current caused by tunnel-junction resistance and to suppress a leakage current from ambipolar current (IAMB). In this paper, we suggest a novel TFET which features double gate, vertical, and trapezoid isosceles channel structure to solve the above-mentioned technical issues. The device design is optimized by examining its electrical characteristics with the help of technology computer-aided design (TCAD) simulation. As a result, double-gate isosceles trapezoid (DGIT) TFET shows a much better performance than the conventional TFET in terms of ON-state current (ION), IAMB, and gate-to-drain capacitance (CGD). It is confirmed that an inverter composed of DGIT-TFETs can operate with less than 1 ns intrinsic delay time and negligible voltage overshoot.

Keywords: FinFET; ambipolar current; scaling; subthreshold swing; tunnel field-effect transistors (TFETs).