III-N polarization-graded transistors for millimeter-wave applications-Understanding and future potential

Abstract

Advanced concepts in polarization engineering of III-N transistor structures are promising for enabling significant improvements in device performance for microwave through millimeter-wave applications. By going beyond the conventional abrupt-interface design concept that has dominated transistor design for decades, dramatic improvements in device linearity, maximum operating voltage, and power-added efficiency through the microwave and mm-wave regimes have been predicted in simulation and experimentally demonstrated. These improvements are enabled by improved physical understanding of electron transport and electrostatics, which can be exploited to enhance carrier velocity and enable intrinsic electric-field management.