Determination of the Junction Temperature under Load Current in GaN Power Devices with Schottky Gate Leakage Current as TSEP

The junction temperature of power semiconductor devices is an important parameter for power system design and reliability determination. In lateral GaN power devices, no pn-junction is present in the load current path and the commonly used V-CE (T) method cannot be applied. For Schottky p-GaN devices, the forward gate leakage current of the Schottky barrier can be used as temperature sensitive electrical parameter (TSEP). By monitoring the gate current at constant gate voltage, a load current independent temperature sensing is applicable. In this paper the I-G (T)-method is used for thermal impedance measurement.