GaN-Based Submicrometer HEMTs With Lattice-Matched InAlGaN Barrier Grown by MBE

GaN-based high electron mobility transistors (HEMTs) with a nearly strain-free high-Al-content quaternary barrier and electron mobilities up to 1590 cm²/Vs have been grown on 4H-SiC using molecular beam epitaxy (MBE). The processed devices with 150-nm gate length exhibit a high dc performance with a maximum current density of 2.3 A/mm and an extrinsic transconductance up to 675 mS/mm that is among the highest values reported until now for any III-N transistor. We further present, to our knowledge, the first power measurements at 10 GHz of MBE-grown GaN HEMTs with nearly lattice-matched InAlGaN barrier achieving 47% power-added efficiency at 10 V and an output power density of 5.6 W/mm at 30-V bias.