Thin-Barrier InAlN/GaN MISHEMTs Using LPCVD Si3N4as Gate Dielectric

In this work, thin-barrier InAlN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MISHEMTs) with high drain current density and low gate leakage are fabricated and analyzed. In order to suppress the gate leakage, wide-bandgap Si3N4 deposited by low pressure chemical vapor deposition (LPCVD) is used as gate dielectric. The device with a gate length of 1.5 $\mu$m demonstrates a drain current of 1.4 A/mm, a gate leakage current of 0.1 $\mu$ A/mm, and a current on/off ratio of $\sim 10^{7}$. In addition, the impact of passivation on the gate leakage of InAlN/GaN MISHEMT is also investigated.