10 A/567 V normally off p-GaN gate HEMT with high-threshold voltage and low-gate leakage current
Normally off p-gallium nitride (GaN) gate high-electron-mobility transistors (HEMTs) on silicon substrate were fabricated with hydrogen plasma treatment technology, which features a high-resistivity cap layer (HRCL) at the access region. With hydrogen plasma treatment at the access region, the normally off operation was obtained with a threshold voltage of +2.5 V based on the linear extrapolation of the transfer curve. The fabricated HRCL-HEMT with a gate width of 49.7 mm exhibits a maximum drain current of 10 A at V GS = 8 V and a high off-state breakdown voltage of 567 V at V GS = 0 V with substrate grounded. Meanwhile, the HRCL-HEMT also shows low-gate leakage current of 1.3 × 10−7 and 3.3 × 10−10 A/mm at V GS = 8 V and = −30 V, respectively. The positive threshold voltage, high drain current, high-breakdown voltage and low-gate leakage show the potential of HRCL-HEMT for power switching applications.
