On the double channel engineering of dual gate AlGaN/GaN HEMTs for heavy ion sensing applications

Abstract

This work investigates the influence of Single Event Transient (SET) effect on Double Channel Dual Gate (DC-DG) AlGaN/GaN HEMT using TCAD simulations. Both Single Channel (SC) and Double Channel HEMT have been calibrated with reported experimental results and further extended by introducing a second gate in the structures to analyze its sensitivity towards heavy ion strike. The effective gate length has been optimized in such a way that the saturation currents and threshold voltage of dual gate devices is similar to that of the single gate devices. The DC-DG HEMT improves the heavy ion sensitivity, thus making it a more viable device for sensing application (mainly radiation). Different biases and gate materials have been used to observe the influence of SET on the DC-DG AlGaN/GaN HEMT. Further, the impact of the graded AlGaN barrier on the device current as well as on the sensitivity of the DC-DG HEMT towards SET is studied. To ascertain the performance of DC-DG HEMT for dosimeter applications, its sensitivity toward heavy ion impact in switched mode is monitored. Investigation reveals that the device current returns to its original order of magnitude after every ion impact, and therefore can be effectively used as a dosimeter.