A simple and reliable wafer-level electrical probing technique for III-nitride light-emitting epitaxial structures

We report an easy-to-implement wafer-level electroluminescence characteriza tion technique for InGaN/GaN light-emitting diodes (LED's) epi-wafers by me ans of multiple electrical probes. By first damaging the p-n junctions of t he LED epilayer at localized spots, diode-like current versus voltage chara cteristics and emission spectra can be obtained at injection currents as hi gh as 100 mA. This alows a relative but reliable comparison of device-relat ed parameters such as differential quantum efficiency, leakage current, and series resistance among LED epi-wafers.