Design and TCAD Study of p-GaN Gate HEMT With a Nanowire Structure for Stable VTH and Self-Clamped Gate Leakage

In this article, a novel p-GaN HEMT is proposed based on an Ohmic p-GaN nanowire gate structure. The p-GaN nanowire structure behaves as a normally on p-FET with MIS-gate characteristics, enabling the device to feature self-clamped ${I}_{\text {G}}$ , large ${g}_{\text {m}}$ , and a stable ${V}_{\text {TH}}$ . The proto-type device is successfully fabricated, featuring a stable ${V}_{\text {TH}}$ . With the help of TCAD simulation, an in-depth analysis of the operation principle, including ${I}_{\text {G}}$ self-clamp effect, ${V}_{\text {TH}}$ recovery process, and sidewall protection is conducted. Scaling down of the p-GaN nanowire structure is analyzed and proved to be an effective way to optimize its performance, where the trade-off relation between the clamping effect of ${I}_{\text {G}}$ and ${V}_{\text {TH}}$ recovery speed is revealed.