Beyond 100 GHz AlN/GaN HEMTs on silicon substrate

A report is presented on high-speed 100 nm AlN/GaN high-electron-mobility transistors (HEMTs) grown on (111) high-resistive silicon substrate. The device delivers an extrinsic peak transconductance g_m=530=mS/mm, a maximum current of 1.74=A/mm, and current gain and maximum oscillation cutoff frequencies of f_t=103=GHz and f_max=162=GHz, which represent the highest cutoff frequencies for AlN/GaN HEMTs on silicon substrate. The results show the outstanding potential of this material system grown on silicon for low-cost high-power millimetre-wave applications.