Direct On-Wafer Non-Invasive Therm Power HFETs Under Microwave

Abstract- For the first time, we report direct on-wafer non-invasive temperature distribution measurements of AlGaN/GaN HFETs grown on Si substrates under microwave large-signal conditions. An infrared camera and a load-pull measurement system coupled to a probe station enable us to produce surface temperature maps with micronic resolution. Results include the impact of the RF drive, differences between RF and DC drive, as well as impact of reduced power added efficiency on the surface temperature of the device. Index Terms- GaN, HFETs, infra-red spectroscopy, reliability, temperature, thermal effects. I