Monolithic integration of enhancement/depletion-mode high electron mobility transistors using hydrogen plasma treatment

Abstract

We demonstrate a planar technique of hydrogen plasma treatment for monolithic integration of enhancement/depletion (E/D)-mode GaN high electron mobility transistors (HEMTs). By hole compensation mechanism, E-mode and D-mode HEMTs based on p-GaN/AlGaN/GaN heterojunctions are simultaneously realized on the same wafer. The fabricated direct-coupled FET logic inverter with a driver/load ratio of 10 exhibits a large output logic swing of 4.78 V, wide noise margins, an ultralow threshold hysteresis of 13 mV, and good temperature stability up to 300 °C, while the fabricated 11-stage ring oscillator shows a propagation delay of 0.8 ns/stage at VDD = 5 V.