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

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 SS_avg (∼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.