High-Power Ka-Band Performance of AlInN/GaN HEMT With 9.8-nm-Thin Barrier

We report the first CW Ka-band radio-frequency (RF) power measurements at 35 GHz from a passivated Al_0.82In_0.18N/GaN high-electron mobility transistor on SiC with 9.8-nm-thin barrier. This device delivered a maximum of 5.8 W/mm with a power-added efficiency of 43.6% biased at V_DS = 20 V and 10% I_DSS when matched for power at CW. The device was grown by metal-organic chemical vapor deposition with 2.8-??m source-drain spacing and a gate length of 160 nm. An excellent ohmic contact was obtained with an R_c of 0.62 ????mm. The maximum extrinsic transconductance was 354 mS/mm with an I_DSS of 1197 mA/mm at a V_GS of 0 V, an ft of 79 GHz, and an f_max of 113.8 GHz.