Investigation of Novel Z-shaped Gate TFET with Improved Device Characteristics

Abstract

This paper proposes a novel Z-shaped gate TFET (ZG-TFET) to enhance the device switching characteristics. The gate terminal is elevated above the N+ pocket region to amplify the electric filed at source-pocket interface. In addition to this, the elevated gate terminal initiates the line tunneling to be occurred in both vertical and lateral direction of the source-pocket interface, which eventually improves the BTBT rate of charges into the channel region of ZG-TFET. The proper optimization of doping concentration and thickness of N+ pocket reduces the tunneling barrier-width at source/channel interface and thereby, increases ION (1.19×10-6A/µm at Vgs=1.2V). As per the obtained TCAD simulation results, the proposed device achieves approximately one order increment in ION, two order increment ION /IOFF ratio and twenty percent improvement in SS as compared to conventional L-shaped TFET. Hence, improvement in switching characteristics helps the proposed ZG-TFET to become more suitable for digital circuit applications.