Suppressed gate leakage and enlarged gate over-drive window of E-mode p-GaN gate double channel HEMTs

A 600-V p-GaN gate double channel HEMT (DC-HEMT) is presented with a systematic investigation of the gate characteristics, including the leakage current, breakdown, and reliability under forward bias stress. It is found that the gate leakage of the DC-HEMT is substantially lower than that of the p-GaN single channel HEMT (SC-HEMT) owing to suppressed electron spillover that stems from hole storage in the quantum well upper channel. Consequently, the gate breakdown voltage of the DC-HEMT is improved to 14.7 V compared to 12.2 V of the SC-HEMT. Besides, the gate operating voltage margin of the DC-HEMT is expanded to 4.2 V compared to 3.3 V of the SC-HEMT according to the gate lifetime evaluation.