First Experimental Realization of a p-FET Based on Single Crystal GaN Substrate

In this study, we report the first p-type channel field-effect transistors (p-FETs) fabricated on single crystal GaN substrate. The p-GaN/u-GaN/AlN/AlGaN structure on GaN substrate exhibits excellent crystal quality and interface. Due to the decrease of threading dislocations (TDs), there is a significant reduction in N-vacancies. Fewer holes are compensated. The p-FET structure on GaN substrate features higher sheet hole density. Moreover, sharp interface reduces the interface roughness scattering, ensuring no degradation of mobility. The p-FETs based on GaN substrate have higher performance benefit from lower sheet resistivity. Specifically, the saturation current of the p-FET is boosted by 7 times compared to the p-FET on sapphire substrate. These results demonstrate the remarkable potential of GaN substrate for the realization of high-performance p-FET.