Investigation on the interface trap characteristics in a p-channel GaN MOSFET through temperature-dependent subthreshold slope analysis

In this paper, a simple method based on subthreshold slopes was proposed to investigate the interface trap characteristics in a p-channel GaN MOSFET with a p-GaN/AlGaN/GaN structure on Si. The energy distribution of the interface trap density has been extracted from the analysis of the transfer characteristics in the subthreshold region of operation. The interface trap densities and respective energy distribution at both room temperature and 150 °C were also calculated from the ac conductance measurements at corresponding applied biases. Both characterization methods show similar results of trap densities and energy levels.