A Simple Method to Extract the Thermal Resistance of GaN HEMTs from De-trapping Characteristics

This paper proposes a new method for extracting the thermal resistance of GaN-based HEMTs using pulse recovery data. After the device temperature and trapping state are established from different quiescent power dissipations for several base-plate temperatures, the recovery profile of the drain current is measured. The recovery time is then used as a temperature-sensitive electrical parameter to extract the thermal resistance of the device. The proposed method has been applied to a Schottky-gate HEMT on SiC, for which a thermal resistance of 15.7 °C-mm/W was extracted, a value in good agreement with others reported for similar devices. Comparison with the one obtained from a step response is also done. Finally, the uncertainties of the proposed method related to the pulse width, temperature, percentage of the drain current recovery time, and averaging procedure are discussed.