GaN/AlGaN high electron mobility transistors with f τ of 110 GHz

The performance of 50 nm gate length GaN/AlGaN HEMTs is reported. The device layers were grown by MBE directly onto an SiC substrate. Devices exhibit a maximum drain current density of 1.2 A/mm, an extrinsic fτ of 110 GHz and an fmax of over 140 GHz. The fτ of 110 GHz is the highest reported to date for a GaN/AlGaN HEMT, a nearly 50% increase over the previous record.