AlGaN/AlN/GaN high-power microwave HEMT

In this letter, a novel heterojunction AlGaN/AlN/GaN high- electron mobility transistor (KNIT) is discussed. Contrary to normal HEMTs, the insertion of the very thin AIN interfacial layer (similar to1 nm) maintains high mobility at high sheet charge densities by increasing the effective DeltaE(C) and decreasing alloy scattering. Devices based on this structure exhibited good DC and RF performance. A high peak current 1 A/mm at V-GS = 2 V was obtained and an output power density of 8.4 W/mm with a power added efficiency of 28% at 8 GHz was achieved.