Reverse-bias Electroluminescence Observation for Reliability Investigations of the InGaN LED

Abstract

The reverse-bias operation of the InGaN LED device can shed a light on device reliability problems. Our goal is to use noninvasive optical characterization techniques including surface temperature measurements, 2D XRF( X-ray fluorescent) element analysis, and 2D electroluminescence measurements to visualize the leakage current distribution and examine the origin of the reverse-bias leakage current. The origin of the reverse-bias emission is attributed to imperfect metal contact caused by process variation. Hot electron induced emission due to the leakage current should be the mechanism of the reverse-bias emission from the surface defect and the imperfect contact. The light emission was proved to be relevant to reliability problems in terms of the leakage current.