100 nm T-gate GaN-on-Si HEMTs Fabricated with CMOS-Compatible Metallization for Microwave and mm-Wave Applications

100 nm T-gate GaN-on-Si HEMTs fabricated using CMOS-compatible Au-free Ta/Al ohmic and Ti/Al gate contacts are reported in this work. The device exhibited a maximum drain current of 1.82 A/mm, a peak transconductance of 489 mS/mm, a cut-off frequency $f_{\mathrm{T}}$ of 102 GHz, and a maximum oscillation frequency $f_{\max}$ of 114 GHz. Good RF performance comparable to their counterparts with Au-contained processes is achieved, demonstrating its potential for cost-effective microwave and mm-wave applications.