Small-Signal, High Frequency Performance of Vertical GaN FinFETs with fmax = 5.9 GHz

GaN vertical finFETs are capable of high breakdown voltages and large current density without the need for regrowth or p-type doping. These attributes make them a promising candidate for next-generation high-frequency power applications. Here, we demonstrate the first high frequency characterization of vertical GaN finFETs. These devices utilize a highly insulating sapphire substrate and a quasi-vertical design that avoids the expensive bulk-GaN substrates typically used in vertical power applications. Moreover, contacts remain on the top of the wafer, thereby enabling high-frequency characterization and potentially easing future system integration.