Measurement and Modeling of GaN HEMTs Operating at 500 °C

Device characterization and modeling, including RF performance, of AlGaN/GaN high-electron-mobility transistors (HEMTs) from 22 °C to 500 °C are presented in this paper. The HEMTs measured achieved a maximum drain current density of 580 mA/mm at 500 °C which is less than 50% reduction from 22 °C. Small-signal on-wafer measurement shows f
T
/f
MAX
values of 18.8/14.1 GHz at 22 °C and 5.3/3.3 GHz at 500 °C. An MIT Virtual Source GaN FET (MVSG) model is extracted and optimized to capture the device behavior. The device operation at high-temperature is studied and analyzed. Adding a temperature dependent extrinsic RC network to the MVSG model greatly improved small-signal modeling for devices in extreme environments.