Large-Periphery ALGaN/GaN High Electron Mobility Transistors for High-Power Operation

We report on AlGaN/GaN high electron mobility transistors (HEMTs) for high-power operation achieved by selective-area growth (SAG) technique based on plasma-assisted molecular beam epitaxy (PAMBE). Significant improvements in current density and on-state resistance were observed when SAG was employed. Maximum current of 1.75A and on-state resistance of 4.76mΩ cm² were demonstrated for a large-periphery HEMT with total gate width of 5.2mm. Low Schottky gate leakage current was also realized by the suppression effect of SAG and the use of Si₃N₄/SiO₂ gate insulators, leading to a high gate breakdown voltage of over 200V at a short gate-to- drain distance of 6μm.