AlScN/GaN HEMTs Grown by Metal-Organic Chemical Vapor Deposition With 8.4 W/mm Output Power and 48 % Power-Added Efficiency at 30 GHz

We report on DC and RF measurement results of AlScN/GaN high electron mobility transistors (HEMTs) grown by metal-organic chemical vapor deposition (MOCVD). Comparing the properties with those of a wafer grown with the same MOCVD tool but featuring an AlGaN barrier, the sheet carrier density ( $\text {n}_{\text {s}}$ ) of $1.50\times 10^{{13}}$ cm $^{-{2}}$ measured on the AlScN/GaN wafer is around 60 % higher. This translates to a power density ( $\text {P}_{\text {out}}$ ) of 8.4 W/mm at a frequency of 30 GHz and a drain bias of 30 V. Also, a high power-added efficiency (PAE) of 48.9% and 46.1% is reached, when biased at 25 V and 30 V, respectively. These early results illustrate the great potential AlScN/GaN devices carry for improving on the achievable output power on device level at millimeter-wave (mmWave) frequencies.