Investigation of gate-all-around tunnel-FETs with drain doping and high-density layer for RF figure of merit

In this work, we investigate the impact of drain doping and a high-density layer (HDL) at the source-channel interface of a Gate All Around Tunnel Field-Effect Transistor (GAA-TFET) on the radio frequency (RF) performance. Results depict that a lateral asymmetric doping profile in the drain region suppresses ambipolar conduction, OFF current (I_OFF = 1.51 × 10⁻²⁰ A μm⁻¹), and the capacitance of the gate to drain (C_GD). Additionally, the HDL at the source-channel junction reduces the overall depletion area, enhancing the ON current (I_ON = 1.52 × 10⁻⁵ A μm⁻¹) and low subthreshold slope (SS) of 40 mV dec⁻¹ achieved due to high band gap strip (GaAs) at the drain channel. Here, we also investigate the impact of lateral asymmetric drain doping and HDL on RF performance for GAA-TFET for different channel lengths. In addition, we analyze the transconductance (g_m), unity-gain cut-off frequency (f_T), gain bandwidth product, and maximum oscillation frequency (f_max) to evaluate the RF figure of merit (FoM) for the GAA-TFET using the Silvaco TCAD tool.