“…Due to the rapid advances in the hydride vapour phase epitaxy (HVPE) technique, free-standing GaN substrates are commercially available and open the possibility of developing GaN-based vertical power diodes and transistors like trench MOSFETs [1]. As compared to the high-electron mobility transistors (HEMTs) made-up on heterostructures grown on foreign substrates, the vertical Schottky barrier diodes (SBDs) on homoepitaxial GaN substrate offer several advantages such as latticed matched epilayer, absence of thermal expansion coefficient (TCE) mismatching, reduced dislocation density (< 10 7 cm -2 ) in the active volume, less sensitivity to the surface trapping effects (as the current flows through the vertical direction), and better device scalability [1][2][3][4]. The vertical GaN-on-GaN SBDs can deliver high on-state current, low leakage current density, and improved breakdown voltage than the lateral diodes.…”