Radiation-Sensitive AlGaN/GaN MOS-HEMT-Based Dosimeter

An AlGaN/GaN MOS-HEMT (metal oxide semiconductor–high electron mobility transistor)-based dosimeter has been proposed to demonstrate and evaluate the impact of absorbed doses of radiations by virtue of interface trap charges at the interface of SiO2/AlGaN. The effect of various radiation doses induced (Nt = − 3 × 1012cm−2 to + 3 × 1012cm−2) has been studied in terms of various electrical parameters, such as channel conductance (gd), drain current (Ids), transconductance (gm), and threshold voltage(Vth). Variations in the drain current and channel potential, and a significant shift in the threshold voltage, have been observed. Threshold voltage and drain current increase proportionally to the radiation dose induced due to the addition of positive charges on the surface, leading to increased charge carrier concentration in two-dimensional electron gas (2DEG). Modifying the electron mobility/or density by the effects of induced radiation affects the functionality of the 2DEG-based device. The maximum changes in output conductance, drain current, threshold voltage change, drain-on sensitivity, and transconductance observed for the proposed sensor are 69%, 0.073 A, 593 mV, 0.314, and 0.018 S, respectively. The effects of variation in gate length on the threshold voltage sensitivity and sensor drain current have been studied.