Characterization of GaN HEMT at Cryogenic Temperatures

In this work, 250nm gate length AlGaN/GaN HEMT characterization results are presented at cryogenic temperatures, up to 10 K. Impact of interface and bulk traps on device trans-conductance (Gm) and output conductance (Gds) is analysed with respect to temperature variation. Hysteresis window in transfer as well as output current characteristics is observed which indicates the presence of traps in the device. Hysteresis window is observed to be widened at low temperature due to lower average kinetic energy of the electrons.