Two-Dimensional Electron Dynamics in GaN/AlGaN Heterostructures

This report addresses the study of two‐dimensional electron gas (2DEG) transport at low and moderate electric fields. The devices under study are group‐III nitride‐based (AlGaN/GaN) gateless heterostructures grown on sapphire for HEMT applications. The transmission line model (TLM) patterns of different channel lengths L and the same channel width are used. We have developed a simple theoretical model to adequately describe the observed peculiarities in the I–V characteristics measured in steady‐state and pulsed (10—6 s) regimes. The effect of Joule heating of a heterostructure is clearly distinguished. The thermal impedances and the channel temperature rise caused by the Joule self‐heating have been extracted for the devices of different L at different values of dissipated power.