Improved Leakage Current, Output Power, and Electrostatic Discharge Characteristics of GaN LEDs by Chemical Etching

We report the effect of chemical etching of p-GaN using molten KOH:NaOH solution on leakage currents, light output power, and electrostatic discharge ESD characteristics of GaN light-emitting diodes LEDs . Photoluminescence and capacitance–voltage measurement indicated that a deep donor–acceptor pair DDAP was densely concentrated near the p-GaN surface region 18 nm and the defects were effectively removed by a chemical etching process, resulting in a remarkable reduction of defect-assisted leakage current on the forward and reverse bias, and improved light output power due to enhanced injection efficiency in etched GaN LEDs. The negative-voltage ESD characteristics of etched GaN LEDs were also improved due to the decrease in DDAP defects near the surface region of p-GaN. © 2008 The Electrochemical Society. DOI: 10.1149/1.3020765 All rights reserved.