Current conduction paths in GaN

Abstract

Studies current conduction using C-AFM on a variety of GaN samples grown by MBE and HVPE on sapphire, both before and after performing chemical etches to delineate defect structures. Samples employed both side ohmic contacts and a conventional Schottky barrier configuration. The results indicate that the major current conduction paths in forward direction below the threshold of the metal-semiconductor junction turn-on are associated with prismatic planes. The same is true for the reverse current case. The Schottky barrier experiments indicate the planarized surfaces exhibit much lower excess current.