Average Temperature Determination of AlGaN/GaN HEMT Utilizing Pinch-Off Voltage Biasing

In this article, pinch-off voltage biasing was utilized for the first time to determine the average channel temperature of the AlGaN/GaN HEMT, which made it possible to exclude the device’s electrical parameters dependence in the linear operating mode. The theoretical part is focused on the thermal model with temperature-dependent thermal resistance utilization for active area average temperature determination of the HEMT under quasi-static operation. The experimental part deals with drain-to-source current comparison utilizing quasi-static and pinch-off voltage-biased short-pulse output ${I}$ – ${V}$ characteristics and additional isothermal trapping phenomena determined from the threshold voltage shift. The appropriate use and combination of methods for the active area average temperature determination utilizing constant isothermal saturation current or short-pulse current were discussed.