Gate Recessed Quasi-Normally OFF Al₂O₃/AlGaN/GaN MIS-HEMT With Low Threshold Voltage Hysteresis Using PEALD AlN Interfacial Passivation Layer

摘要

In this letter, a gate recessed normally OFF AlGaN/GaN MIS-HEMT with low threshold voltage hysteresis using Al₂O₃/AlN stack gate insulator is presented. The trapping effect of Al₂O₃/GaN interface was effectively reduced with the insertion of 2-nm AlN thin interfacial passivation layer grown by plasma enhanced atomic layer deposition. The device exhibits a threshold voltage of +1.5 V, with current density of 420 mA/mm, an off-state breakdown voltage of 600 V, and high on/off drain current ratio of (sim 10^{mathrm {mathbf {9}}}) .