High-Performance AlN/GaN MIS-HEMT With Dual-Nitridation GeON Dielectric

In this letter, AlN/GaN MIS-HEMT with dual-nitridation GeON dielectric is reported. The gate trench and barrier surface were pretreated by N plasma pulses, after which Ge was evaporated and converted into GeON by additional N plasma treatment. Thanks to the high-quality GeON dielectric and optimized interface, the MIS-HEMT exhibits excellent performance, including effective suppressed current collapse, reduced gate leakage, and improved breakdown voltage. The MIS device achieves an 80 GHz cut-off frequency (fT) and 128 GHz maximum oscillation frequency (fMAX). At 30 GHz, the devices show Psatof 1.08/1.63/1.90 W/mm with peak PAE of 46.4/48.1/50.4% and linear gain of 12.5/14.2/14.8 dB at low drain voltages of 3.5/5/6 V, respectively. These results demonstrate the significant potential of this MIS device for high-power, high-efficiency, low-voltage RF applications.