Microwave performance of AlGaN/GaN metal insulator semiconductorfield effect transistors

摘要

Metal-insulator semiconductor field effect transistors (MISFETs)from surface-passivated undoped AlGaN/GaN heterostructures werefabricated on sapphire using a gate-window process that does notseverely impact its performance. Measured static output characteristicsinclude full channel currents (I_max) of roughly 750 mA/mm andpeak transconductances (g_m) of 100-110 mS/mm. With evidencefor reduced DC-to-RF dispersion from gate-lag measurements, thesedevices at 4 GHz with 28.0 V bias generated maximum output powerdensities of 4.2 W/mm and 36% power added efficiency. The process whenapplied to 2-inch wafers produced with high yield 0.6-μm MISFETsexhibiting consistent static performance over the whole wafer with amean I_max value of 754 mA/mm and a mean g_m valueof 66 mS/mm at an impressive standard deviation <5%