Power Performance of AlGaN/GaN High‐Electron‐Mobility Transistors with AlN Buffer on SiC Substrate at 3.5 GHz

Herein, a 3.5 GHz (S‐band) power performance is reported on an AlGaN/GaN high‐electron‐mobility transistor (HEMT) with AlN buffer on SiC substrate. A 4 inch epi‐wafer is grown by high‐temperature metal–organic chemical vapor deposition. The fabricated devices with a 400 nm gate and direct current and radio‐frequency (RF) characteristics are examined. These device shows a transconductance of 233 mS mm −1 and a maximum drain current of 820 mA mm −1 . The pulsed current–voltage ( I–V ) characteristic shows a low slump ratio with a 0.36% and 2.2% for Z 1 and Z 2 , respectively. The power performance shows output power = 5.5 W mm −1 with 54.3% power added efficiency, and V DS was 50 V. The potential of an AlN buffer HEMT is demonstrated by the results for use in next‐generation high‐power RF devices.