Simple and Accurate Method to Estimate Channel Temperature and Thermal Resistance in AlGaN/GaN HEMTs

Self-heating effects in AlGaN/GaN high-electron mobility transistors grown on three different substrates have been evaluated for ambient temperatures between 0°C and 225°C. A simple and accurate electrical method for the estimation of channel temperature is proposed. This technique is based on the difference in drain current between dc and short-pulsed conditions. Being an electrical method, neither special geometry nor expensive equipments are required. Simulations have also been performed to confirm the results. We have applied our technique to different device structures and geometries, demonstrating its sensitivity and validity at different ambient temperatures.