Method for Estimation of the Channel Temperature of GaN High Electron Mobility Transistors

A quick and reliable method to estimate the channel temperature of GaN high electron mobility transistors is extremely important in order to understand the physical degradation mechanisms as well as to extract a meaningful life time of the device. In this work, we present a simple yet powerful method to electrically measure the channel temperature of GaN HEMTs with a synchronized pulsed I-V setup. To validate the technique, we extract thermal resistance a) on the same device, multiple times, b) on multiple identical devices on the same wafer, c) on devices with different geometries and d) on identical devices with different level of degradation.