In Situ Junction Temperature Measurement and Thermal Resistance Extraction of AlGaN/GaN HEMTs Using Schottky Diode-Integrated Sensor

This paper presents a new method for real-time in-situ temperature measurement and thermal resistance extraction of AlGaN/GaN high electron mobility transistors (HEMTs) based on Schottky diode integrated sensors for the first time. Through an innovative structure design, the independent Schottky diode sensor is integrated near the gate of the HEMT, and the fabrication process is fully compatible with the standard electrode manufacturing process. Experimental results show that the sensor has a temperature sensitivity of 4.192 mV/°C (testing current = 1.0 μA) and a time resolution of microsecond is achieved, which can realize transient temperature monitoring without affecting the operation state of the device. It shows high temperature sensitivity without measurement delay time caused by circuit switching. Meanwhile, it does not require the damage to package which is necessary in the optical methods. It can accurately capture the transient temperature change of the hot spot near the gate and construct the structure function, so as to extract the thermal resistance of each layer of the package device. The integrated sensor provides an effective characterization method for the thermal management optimization of power devices, and shows an important application value in the field of reliability analysis and heat dissipation design. This method can also serve as a benchmark for evaluating alternative temperature-measurement techniques.