A study of the failure of GaN-based LEDs submitted to reverse-bias stress and ESD events

This paper describes an extensive analysis of the degradation of InGaN-based LEDs submitted to reverse-bias stress and Electrostatic Discharge events. Results described within the paper indicate that: (i) reverse-bias current flows through localized leakage paths, related to the presence of structural defects; (ii) the position of these paths can be identified by means of emission microscopy; (iii) reverse-bias stress can induce a degradation of the electrical characteristics of the devices (decrease in breakdown voltage); (iv) degradation is due to the injection of highly accelerated carriers through the active region of the LEDs, with the subsequent generation/propagation of point defects; (v) the localized leakage paths responsible for reverse-current conduction can constitute weak regions with respect to reverse-bias ESD events.