Analog/RF Performance of T-Shape Gate Dual-Source Tunnel Field-Effect Transistor

Abstract

In this paper, a silicon-based T-shape gate dual-source tunnel field-effect transistor (TGTFET) is proposed and investigated by TCAD simulation. As a contrastive study, the structure, characteristic, and analog/RF performance of TGTFET, LTFET, and UTFET are discussed. The gate overlap introduced by T-shape gate can enhance the efficiency of tunneling junction. The dual-source regions in TGTFET can increase the on-state current (I_ON) by offering a doubled tunneling junction area. In order to further improve the device performance, the n+ pocket is introduced in TGTFET to further increase the band-to-band tunneling rate. Simulation results reveal that the TGTFET’s I_ON and switching ratio (I_ON/I_OFF) reach 81 μA/μm and 6.7 × 10¹⁰ at 1 V gate to source voltage (V_g). The average subthreshold swing of TGTFET (SS_avg, from 0 to 0.5 V V_g) reaches 51.5 mV/dec, and the minimum subthreshold swing of TGTFET (SS_min, at 0.1 V V_g) reaches 24.4 mV/dec. Moreover, it is found that TGTFET have strong robustness on drain-induced barrier lowering (DIBL) effect. The effects of doping concentration, geometric dimension, and applied voltage on device performance are investigated in order to create the TGTFET design guideline. Furthermore, the transconductance (g_m), output conductance (g_ds), gate to source capacitance (C_gs), gate to drain capacitance (C_gd), cut-off frequency (f_T), and gain bandwidth (GBW) of TGTFET reach 232 μS/μm, 214 μS/μm, 0.7 fF/μm, 3.7 fF/μm, 11.9 GHz, and 2.3 GHz at 0.5 V drain to source voltage (V_d), respectively. Benefiting from the structural advantage, TGTFET obtains better DC/AC characteristics compared to UTFET and LTFET. In conclusion, the considerable good performance makes TGTFET turn into a very attractive choice for the next generation of low-power and analog/RF applications.