2.57GW/cm2 normally-off composite stepped gate GaN-based HEMT with p-GaN buried layer and field plate

This article proposes for the first time the use of a stepped channel to increase the threshold voltage(V th ). At the same time, its working mechanism was explained and the step height was optimized. However, the stepped channel has a limited ability to increase V th . Through structural improvement, a composite stepped gate is proposed and the threshold voltage can be as high as 3.5V.In addition, to expand the application range of the device, a p-GaN buried layer and a field plate are introduced to form a composite stepped gate GaN-based HEMT with p-GaN buried layer and field plate to reduce leakage current and adjust the electric field distribution of the device. Through structural optimization, the breakdown voltage of the device can reach 2440V, and the figure of merit (FOM) is as high as 2.57GW/cm 2 . It shows that the composite stepped gate GaN-based HEMT with p-GaN buried layer and field plate has great potential in the field of high-power devices. In addition, it also has great advantages in communication system applications by RF linearity analysis.