Al0.64Ga0.36N channel MOSHFET on single crystal bulk AlN substrate

Abstract

We report MOCVD-grown Al0.87Ga0.13N/Al0.64Ga0.36N metal-oxide-semiconductor-heterojunction-field-effect-transistors on single crystal bulk AlN substrate. As compared to control devices on AlN template, thermal impedance for devices on single crystal AlN decreased to 1/3 from 31 to 10 K mm W−1, comparable to SiC and copper heat-sinks. This represents a significant thermo-electric co-design advantage over other semiconductors. As a result, the peak drain saturation current increased from 410 to 610 mAmm−1. A 3-terminal breakdown field of 3.7 MV cm−1 was measured, which to date represents state-of-the-art performance for devices with similar Al x Ga1−xN-channel composition. This translates to a measured Baliga figure of merit of 460 MWcm−2