In this paper, a C-shaped pocket tunnel field effect transistor (CSP-TFET) has been designed and optimized based on the traditional double-gate TFETs by introducing a C-shaped pocket region between the source and channel to improve the device performance. A gate-to-pocket overlapping structure is also examined in the proposed CSP-TFET to enhance the gate controllability. The effect of pocket length, pocket doping concentration and gate-to-pocket overlapping structure on the DC and analog/RF characteristics of the CSP-TFET are estimated after calibrating the tunneling model in double-gate TFETs. The DC and analog/RF performance such as on-state current (I on ), on/off current ratio (I on /I off ), subthreshold swing (SS), transconductance (g m ), cut-off frequency (f T ), and gain-bandwidth product (GBP) are investigated. The optimized CSP-TFET device exhibits excellent performance with high I on (9.98×10-4 A/μm), high I on /I off (~1011), as well as low SS (~12 mV/dec). The results reveal that the CSP-TFET device could be a potential alternative for the next generation of semiconductor devices.

In this paper, 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 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. And 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, and this combination design substantially reduces the ambipolar current. The results show that the CSP-DMUN-TFET has excellent performance, including high I on (9.03×10-4 A/μm), high I on/I off (~1011), low SS avg (~13 mV/dec), low I amb (2.15×10-17 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 for next generation of semiconductor devices.