Π-shape Gate Structure Design for MOS Combined with p-GaN AlGaN/GaN HEMTs

GaN as a typical third generation wide-bandwidth semiconductor material is widely used in various power devices and sensor devices. However, depletion devices are conventional GaN-based HEMTs, and in practical applications, additional negative gate voltage is usually required to turn off the channel, which leads to an increase in system power consumption, for this reason enhanced HEMT devices need to be developed. In order to enhance the functionality of enhanced GaN-based HEMTs, Al- GaN/GaN hetero structured HEMT with Π-shape p-type gate GaN combined with MOS structure is designed in this paper. A comprehensive analysis was carried out to compare the output characteristics, transfer characteristics, transconductance and breakdown characteristics of the devices with those of common p-type GaN gate structure AlGaN/GaN HEMT devices. The results show that the hybrid structure of Π-shape p-type gate and MOS is able to increase the current density, the on-resistance is reduced, which greatly improves the output current of the device, but the break down voltage is almost equal, in addition, the gate control of the channel is enhanced at almost the same threshold voltage.