A new gate design combined MIS and p-GaN gate structures for normally-off and high on-current operation

This study proposes a new gate architecture that integrates both a p-GaN gate and a metal-insulator-semiconductor (MIS) structure for a normally-off AlGaN/GaN high electron mobility transistor. Silvaco TCAD simulation software is used to assess the performance of the proposed design. A comprehensive analysis of the device's transfer, output, and breakdown characteristics is carried out and compared with the conventional p-GaN gate AlGaN/GaN HEMT. The findings indicate that incorporating MIS in conjunction with the p-GaN gate leads to an augmentation in the on-state current density and a reduction in on-resistance. The proposed HEMT exhibits superior attributes, with an 80% increase in drain current compared to the conventional p-GaN gate HEMT, but remains similar to threshold voltage and breakdown voltage. Consequently, the proposed HEMT demonstrates elevated current density and enhances gate control over the channel without modifying the threshold voltage compared to the conventional p-GaN gate HEMT.