Vertical gallium nitride fin transistors for RF applications

Abstract

This thesis presents the development, fabrication, and characterization of the first vertical gallium nitride fin transistors for radio frequency applications. The basic device design is adapted from vertical fin power transistors with modifications made to improve frequency performance, system integration, and uniformity. Specifically, a new, self-aligned gate process allows for dramatic scaling of gate lengths; a highly uniform planarization process improves device yield and reliability; and layout adjustments reduce parasitics and allow for on-wafer, high-frequency testing of vertical devices. These advancements are a promising step in enabling the next generation of radio frequency electronics powered by gallium nitride.