Feasibility Analysis of Parameter-Based Temperature Estimation of pGaN Power HEMTs Under Consideration of Charge Carrier Trapping

In this paper, several typical temperature sensitive electrical parameters are investigated regarding their applicability in Schottky-contact and Gate-Injection GaN HEMTs. In addition, the effect of charge carrier trapping on the temperature behavior of the threshold voltage and gate current is analyzed. It is found that the drain-source on-resistance, the drain-source capacitance, and the transconductance can all be exploited for temperature estimation. On the other hand, shifting of the threshold voltage due to gate voltage stresses obfuscates any shifting caused by temperature changes in Schottky-contact device and the ohmic-contact device to a smaller degree. The gate current of the Schottky-contact device is also stress-dependent around the threshold voltage, but stabilizes at higher gate-source voltage values. In contrast, the gate current of the ohmic-contact device is unaffected by gate stress in the transistor on-state.