GaN Power Schottky Diodes

Metalorganic Chemical Vapor Deposition (MOCVD) GaN films were grown simultaneously on multiple substrates ranging in threading dislocation density from 10(3) to 10(10) cm(-2). GaN power Schottky diodes were fabricated on these films to examine the role of crystalline defects on the performance of these devices. For films grown on each of the four substrates, the breakdown voltages did not approach the theoretical limit of approximate to 1600 V. This was an unexpected result, in particular for films grown on the truly bulk GaN which demonstrated superior crystallinity as indicated by x-ray diffraction. We speculate that point defects, possibly carbon, are playing a role in the performance of these devices.