Analysis of intrinsic reverse leakage current resulting from band-to-band tunneling in dislocation-free GaN p–n junctions

Abstract

This work examined reverse leakage currents in GaN p–n junctions nearly free of dislocations. Diodes with shallow bevel mesas and breakdown voltages (BVs) in the range of 130–1000 V exhibited avalanche breakdown at the designed voltages. Significant leakage currents were observed in response to reverse bias values far below the BVs and a weak effect of temperature was also evident. The data were explained based on direct band-to-band tunneling (BTBT). The BTBT current was dominant in those devices having BVs of several hundred volts but was far below the detection limit in the case of a 1000 V class diode.