Influence of Varying Recessed Gate Height on Analog/RF Performances of a Novel Normally-Off Underlapped Double Gate AlGaN/GaN-based MOS-HEMT

Abstract

Current transistor technology has issues with off-state current which reduces power efficiency. The paper presents a novel Normally-off Underlapped Dual Gate (U-DG) AlGaN/GaN MOS-HEMT device to tackle these issues. A novel dual recessed gate technology is implemented in the device which deepens the depletion region, creating a strong barrier that prevents current flow at negative gate voltage. The study investigates various recessed gate heights’ impact on analog and RF performance. Key parameters like drain and gate Currents, transconductance, and transconductance generation factor were analyzed, alongside intrinsic capacitance, gate capacitance, intrinsic resistance and maximum oscillation frequency. Results indicate that a 19 nm recessed gate height offers optimal performance. It is the only one to achieve a normally off state and a substantial 45% increase in transconductance compared to other heights. This research provides crucial insights into designing efficient Normally-off U-DG AlGaN/GaN MOS-HEMT devices, particularly relevant for low-power applications.