Ambipolar performance improvement of the C-shaped pocket TFET with dual metal gate and gate–drain underlap

Abstract

Dual-metal gate and gate–drain underlap designs are introduced to reduce the ambipolar current of the device based on the C-shaped pocket TFET(CSP-TFET). The effects of gate work function and gate–drain underlap length on the DC characteristics and analog/RF performance of CSP-TFET devices, such as the on-state current (I on), ambipolar current (I amb), transconductance (g m), cut-off frequency (f T) and gain–bandwidth product (GBP), are analyzed and compared in this work. Also, a combination of both the dual-metal gate and gate–drain underlap designs has been proposed for the C-shaped pocket dual metal underlap TFET (CSP-DMUN-TFET), which contains a C-shaped pocket area that significantly increases the on-state current of the device; this combination design substantially reduces the ambipolar current. The results show that the CSP-DMUN-TFET demonstrates an excellent performance, including high I on (9.03 × 10−9 A/μm), high I on/I off (∼1011), low SSavg (∼13 mV/dec), and low I amb (2.15 × 10−2 A/μm). The CSP-DMUN-TFET has the capability to fully suppress ambipolar currents while maintaining high on-state currents, making it a potential replacement in the next generation of semiconductor devices.