Temperature monitoring of short-gate length AlGaN/GaN HEMT via an integrated sensor

This paper describes a new method to measure AlGaN/GaN High Electron Mobility Transistors (HEMTs) operating temperature in devices dedicated to RF application. A resistive nickel temperature sensor is integrated into HEMT active area. The technological process development permits to integrate the sensor close to the transistor hot spot providing HEMT temperature under operation. A maximal temperature of 68°C is extracted for a dissipated power of 3.5 W/ mm corresponding to a thermal resistance of 10.6 Kmm/W. This new method shows the capability to monitor component self-heating in real time and to predict its failure. Furthermore, it is shown that the sensor has no influence on DC HEMT electrical behavior and its impact on current and power cutoff frequencies is negligible.