N-Polar AlGaN/GaN MIS-HEMTs on SiC with a 16.7 W/mm power density at 10 GHz using an Al2O3 based etch stop technology for the gate recess

This paper presents the X-band and C-band power performance of MOCVD grown N-polar AlGaN/GaN MIS-HEMTs grown on semi-insulating SiC substrates. Additionally, an AI₂O₃ based etch stop technology was demonstrated for improving the manufacturability of N-polar GaN HEMTs with Si_xN_y passivation. The reported output power densities of 16.7 W/mm at 10 GHz and 20.7 W/mm at 4 GHz represent the highest reported values so far for an N-polar device, at both of these frequencies.