Electro-thermal modeling of multifinger AlGaN/GaN HEMT device operation including thermal substrate effects

AlGaN/GaN high electron mobility transistor (HEMT) device operation was modeled from the sub-micrometer scale to the substrate using a combination of an electro-thermal device model for the active device with realistic power dissipation within the device and a coupled three dimensional thermal model to account for the substrate. Temperatures for various points within a device were determined as a function of biasing conditions, substrate thickness and temperature, number of fingers, and gate length and pitch. As an example, we have used our model to show that life test results of industry-relevant devices can be significantly affected by the exact testing technique used.