A 3-kV GaN MISHEMT With High Reliability and a Power Figure-of-Merit of 685 MW/cm2

In this letter, GaN metal-insulator-semiconductor high electron mobility transistors(MISHEMTs) are fabricated on Si substrates with an ultra-high breakdown voltage of over 3 kV usinga 90-nm in situ SiNX layer as both the gate dielectric and surface passivation. The devices exhibitlow off-state leakage current (on/off ratio of 10(9)), high forward gate breakdown voltage (>122 V), andstate-of-the-art figure of merit (685 MW/cm(2)). Moreover, the reliability of the in situ SiNX dielectric isevaluated through the high-temperature gate bias test. The results are fitted with a Weibull distribution,estimating a 10-year estimation of 100 ppm. The maximum gate-source voltage of over 70 V is obtained.This letter presents a strategy for mass producing GaN-on-Si MISHEMTs with high breakdown voltageand reliability