InAlN/AlN/GaN Field-Plated MIS-HEMTs with a Plasma-Enhanced Chemical Vapor Deposition SiN Gate Dielectric

We report the studies of In_0.15Al_0.85N/AlN/GaN metal-insulator-semiconductor (MIS) high electron mobility transistors with a field plate (FP) and a plasma-enhanced chemical vapor deposition (PECVD) SiN layer as the gate dielectric as well as the surface passivation layer (FP-MIS HEMTs). Compared with conventional In_0.15Al_0.85N/AlN/GaN high electron mobility transistors (HEMTs) of the same dimensions, the FP-MIS HEMTs exhibit a maximum drain current of 1211 mA/mm, a breakdown voltage of 120 V, an effective suppression of current collapse, about one order of magnitude reduction in reverse gate leakage, as well as more than five orders of magnitude reduction in forward gate leakage. These results confirm the potential of PECVD SiN in the application of the InAlN/AlN/GaN FP-MIS HEMTs.