An inverted T-shaped vertical tunneling InN/InxGa1-xN heterojunction TFET with high current ratio

Abstract

An inverted T-shaped vertical InN/InGaN tunneling field effect transistor (TFET) with polarization-induced doping and high current ratio is proposed and investigated. An optimal structure of the proposed device is given by comparing on-state current, subthreshold voltage, and on-state/off-state current ratio. The polarization effect in III-N material induces electrons and holes in the source and drain regions, and non-physical doping can avoid random dopant fluctuations (RDFs) and high thermal budget. The InN/InGaN heterojunction TFET shows significant improvement over the homojunction TFET. The inverted T-shaped structure involves line and point tunneling simultaneously, so the proposed device can achieve higher on-state current than the conventional device. In addition, the proposed device shows the suppression of ambipolar current. The simulations reveal that the ION/IOFF of the proposed structure is about 6.91 × 1012. These results indicate that the line tunneling structure is still available in the polarization-induced InN/InGaN TFET.