Analysis of trapping effects in AlGaN/GaN HEMTs based on near zero bias output conductance

Abstract

AbstractA simple model is developed for characterization of current collapse caused by electron trapping in AlGaN/GaN HEMTs. Threshold voltages are extracted from near‐zero drain bias output conductance characteristics with respect to gate bias based on 0.2 μs pulsed I –V characteristics at different quiescent bias points. Other device parameters such as effective gate length and electron mobility are also estimated by fitting to a model equation. The results show that a higher negative electric field between gate and drain contacts cause a higher threshold voltage shift in the positive direction and a longer effective gate length, resulting in a larger current dispersion due to trapping of more electrons. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)