GaN/AlN p-channel HFETs with I max >420 mA/mm and ~20 GHz f T / f MAX

A strong need exists for a wide-bandgap p-type transistor counterpart of the n-channel GaN HEMTs for power electronics and novel RF circuits. In this work, the first p-channel nitride transistors that break the GHz speed barrier are demonstrated. By leveraging the unique single-channel high-density polarization-induced 2D hole gas of the GaN/AlN heterostructure, best-in-class contact resistances, and scaled T-gate design, p-channel transistor on-currents of 428 mA/mm are observed, with cutoff frequencies in the 20 GHz regime. These observations demonstrate the unique enabling role of the polarization discontinuity at the GaN/AlN semiconductor heterojunction and offer significant hope for a new high-speed and high-voltage wide-bandgap CMOS device platform for applications in RF and power electronics domains.