High-density plasma-induced etch damage of InGaN/GaN multiple quantum well light-emitting diodes

Plasma-induced damage of InGaN/GaN multiple quantum well (MQW) light-emitting diodes (LEDs) has been studied in terms of forward turn-on and reverse breakdown voltages, together with etch rate and surface morphology. The physical degradation of sidewall along with rough surface morphology of n-GaN caused by increased ion scattering induced the deterioration of the forward and reverse voltages. The forward turn-on voltage was relatively independent of the pressure up to 20 mTorr. The reverse breakdown voltage showed the worst degradation at 75% Cl-2 mainly because of a sidewall contamination. It was found that the turn-on voltage is sensitive to the surface roughness of the etched n-GaN and the breakdown voltage is strongly affected by the sidewall contamination. Annealing under nitrogen after the mesa etching improved the electrical properties of the InGaN/GaN MQW LEDs. (C) 2002 American Institute of Physics.