Thermal modeling and measurements of AlGaN/GaN HEMTs including thermal boundary resistance

In this paper an analysis of thermal behavior of microwave power AlGaN/GaN HEMTs has been carried out through pulsed current–voltage (PIV) measurements and small signal [S] parameters. A special care about trapping effects has been followed where it is shown that the thermal resistance of the device can be accurately determined provided that some assumptions on the trapping behavior of the device are verified. The values obtained have been checked by three dimensional finite element (3D-FE) simulations. Finally, the thermal boundary resistance (TBR) between GaN/SiC has been extracted and compared to literature. The results we have obtained are in line with what can be found. In addition to this first set of results, a second 3D-FE analysis of a larger transistor has been performed and checked thanks to liquid crystal measurements.

► In this study pulse IV measurements are performed to determine thermal behavior of power AlGaN/GaN HEMT.
► Trapping effects are taken into account during the measurement process.
► A cross validation between measurement and finite elements simulation allows us to determine the thermal boundary resistance of GaN/SiC.