Numerical study of a novel GaN vertical FinFET with a p-base structure for high switching performance

In this work, a novel GaN-based vertical power FinFET with an embedded p-base structure is proposed and investigated by TCAD simulations. Owing to the p-base region and heavily doped n-GaN channels, the electrical performance is significantly improved. Among performance measures, the threshold voltage exceeds 1.7 V, which increases the compatibility in the system applications. Also, the specific on -resistance and the breakdown voltage reach 0.277 mΩ cm 2 and 881 V, respectively, indicating a high figure of merit of 2.81 GW/cm 2 . Meanwhile, the p-base region is also employed to flatten the electric field beneath the bottom of each trench, ensuring blocking capability even without a source field plate in the proposed device. The source field plate-free structure of the proposed device exhibits smaller capacitance characteristics, resulting in shorter switching time and smaller switching energy loss. In summary, the proposed device combines the advantages of high threshold voltage, high breakdown voltage, low specific on -resistance and better switching performance.