Nanosecond timescale thermal dynamics of AlGaN/GaN electronic devices

Time-resolved Raman thermography, with a temporal resolution of similar to 10 ns, was used to study the thermal dynamics of AlGaN/GaN electronic devices (high-electron mobility transistors and ungated devices). Heat diffusion from the device active region into the substrate and within the devices was studied. Delays in the thermal response with respect to the electrical pulse were determined at different locations in the devices. Quasi-adiabatic heating of the AlGaN/GaN devices is illustrated within the first similar to 70 ns of device operation. The temperature of devices on SiC was found to reach similar to 25% of the dc temperature when operated with 200-ns-long electrical pulses.