Analysis of III-V material-based dual source T-channel junction-less TFET with metal implant for improved DC and RF performance

Abstract

In this paper, two III-V material-based junctionless tunnel FET devices, D-1 and D-2, are proposed. The proposed device D-1 has a low bandgap (GaSb-based) dual source and a higher bandgap (GaAs-based) T-channel junctionless, and the proposed device D-2 has the same architecture as D-1 in addition to a metal strip implant in the gate oxide near both source regions. Due to junctionless architecture, the proposed D-1 and D-2 eliminate random dopant fluctuations (RDF), remove the need for high thermal budgeting, and give better performance with less variability. The wide bandgap (GaAs) T-channel and the drain region formed far from the gate fully suppress the ambipolarity for both the proposed D-1 and D-2. The low-bandgap GaSb material in the source improves the ON current for D-1 and D-2. Compared to the conventional junctionless TFET (JL-TFET), the proposed D-2 (even at a lower bias of 0.5 V) improves the ON current by 1.7 times and the ION/IOFF ratio by 216.66 times, with a much-reduced average subthreshold swing value of 32.7 mV/dec compared to 70 mV/dec of the conventional JL-TFET. Furthermore, the proposed D-2 also provides much improved RF performance with a higher transconductance (gm) of 147.8 μs, higher cut-off frequency (fT) of 32.26 GHz, a higher gain-bandwidth product (GBW) of 3.52 GHz, higher transconductance-frequency product (TFP) of 286 GHz, and a lower transit time (τ) of 5 × 10–12 s. Furthermore, we analyze various linearity parameters such as gm2, gm3, VIP2, VIP3, IIP3, and IMD3 for both D-1 and D-2, and our findings indicate that D-2 exhibits improved linearity performance.