AlGaN/GaN HEMTs on silicon carbide substrates for microwave power operation

Results from technology and microwave characterization of large periphery AlGaN/GaN power HEMTs on insulating SiC substrates are presented. The influence of processing steps on device performance is discussed. DC characteristics reveal current densities above 1.2 A/mm and extrinsic transconductances of 275 mS/mm. A power density of 5.2 W/mm @ 2 GHz is obtained for devices up to 2 mm gate width. The maximum power level achieved on-wafer is 13.8 W @ 2 GHz for 4 mm wide devices. A hybrid amplifier using packaged 4 mm devices delivers 15.1 W.