High-Linearity AlGaN/GaN FinFETs for Microwave Power Applications

In this letter, we have proposed a novel AlGaN/GaN FinFET featuring T-shaped gate and extremely linearity of transconductance characteristics (Gm). The formation of AlGaN/GaN nano-fins only in the gate opening region is enabled by a developed fabrication process, which is simple and well compatible with the conventional one. When normalized to effective channel width, the fabricated FinFET delivers a 1.45 times higher current density and a 1.66 times higher output power density as high as 11.3 W/mm at 8 GHz compared with the planar HEMTs, along with clearly improved linearity characteristics thanks to a flatter Gm response afforded by much lower source access resistance. To the best of our knowledge, this is the first demonstration of superior power performance of highlinearity GaN FinFETs, indicating significant advantages of tri-gate configuration over planar HEMTs for microwave power applications.