Lateral AlGaN/GaN diode with MIS-gated hybrid anode for high-sensitivity zero-bias microwave detection

A zero-bias microwave detector using an AlGaN/GaN-on-Si lateral diode featuring a recessed metal/Al₂O₃/III-nitride (MIS) gated hybrid anode (MG-HAD) is experimentally demonstrated. The forward turn-on voltage of the MG-HAD is determined by the threshold-voltage of the 2DEG channel beneath the recessed MIS-gate, and thus the nonlinearity of the device at zero bias can be flexibly modulated by gate recessing. The optimal trench depth of the MIS-gate for zero-bias detection was designed and experimentally determined to be ~23 nm, which enables a high-curvature coefficient of 78 V^-1 at zero bias. The first-order voltage sensitivity, β_V, is as high as 7.8 mV/μW. To the best of the authors´ knowledge, these values are the highest reported for GaN-based zero-bias detectors to date.