Impact of Channel Thickness on the Performance of GaAs and GaSb DG-JLMOSFETs: An Atomistic Tight Binding Based Evaluation

Abstract

In this paper, the performance of GaAs and GaSb based sub-10 nm double-gate junctionless metal-oxide-semiconductor field-effect transistors (DG-JLMOSFETs) have been studied for high-performance switching applications. The quantum transmitting boundary method (QTBM) has been considered for electron transport, and the band structures are accounted for sp3d5s* tight-binding modeling. The channel thickness, tch is varied from 1.7 to 4.7 nm to evaluate the device figure of merits (FOMs). The thinner channel’s device shows a lower OFF-state current, while the ticker channel device allows a higher ON-state current. The threshold voltage is approximately 0.4 V for GaAs DG-JLMOSFETs with tch = 1.7 nm, whereas it reduces to ~0.05 V for that of tch = 4.7 nm. Similar characteristics have been shown in GaSb devices. Besides, a significant impact of tch on the subthreshold swing (SS) and drain-induced barrier lowering (DIBL) is found in GaSb DG-JLMOSFETs compared with those of GaAs devices. The devices show a higher leakage-power dissipation in both channel materials and low-intrinsic delay for thicker tch due to a substantial amount of energy drop. The above results indicate that III-V-based DG-JLMOSFETs are very promising for next-generation high-performance switching technology.

Keywords

• GaAs
• GaSb
• double gate
• junctionless MOSFETs
• nano-scaled device
• short-channel effects (SCEs)