Effect of Pocket Intrinsic Doping on Double and Triple Gate Tunnel Field Effect Transistors

Abstract

Band-to-band tunneling at the source–channel junction of multigate tunnel field effect transistors (TFETs) plays a major role to boost ON current for eliminating short channel effects (SCE). In this paper, the conventional double gate TFET structure (DG-TFET) is designed and modified by applying gate engineering to design triple gate TFET (TG-TFET). The work mainly focuses on drain current (ION) assessment, fast switching ratio (ION/IOFF), and subthreshold swing (SS) by comparing between conventional DG-TFET and proposed TG-TFET with pocket intrinsic layers. The variation of drain current for different pocket intrinsic doping conditions on TFET performance has been reviewed and demonstrated with SILVACO TCAD simulator. The pocket intrinsic triple gate TFET shows a higher ION and better ION/IOFF ratio of 5.51 for source and pocket doping of 1 ×1020 cm−3 and 1 × 1015 cm−3. This provides 68.51% fast switching ratio as compared to other non-conventional tunnel FETs. But the subthreshold swing (SS) is limited by variation of pocket doping from 100 to 1018 cm−3 for TG-PI-TFET, since DG-PI-TFET provides better subthreshold swing of 23.93 mV/dec (≪60 mV/dec) considering the leakage current for low-power applications.