GaN based transistors for high temperature applications

We review theoretical and experimental results for GaN-based field effect transistors (FET) and discuss their potential for high temperature applications. We demonstrate that a decrease in ionized impurity scattering with an increase in temperature makes AlGaN-GaN DC-HFET to be superior candidates for high temperature applications. In these devices, a large sheet carrier concentration in the device channel allows us to obtain a relatively low parasitic series resistance and to achieve superior dc and ac performance (with the cutoff frequency times gate length product of 18.3 GHz × μm demonstrated recently by our group at room temperature).