Electrostatic discharge induced degradation of GaInAsP/InP laser diodes caused by argon ion irradiation in facet coating

The ESD induced degradation is one of the most important reliability characteristics of GaInAsP/InP LDs. We clarified the ESD induced degradation mechanism caused by the argon ion irradiation in the facet coating. By the angle resolved XPS analysis of ion-irradiated InP (100) surface, the lack of phosphors and oxidation were found. It means the generation of the dangling bonds and increase of the surface recombination. Then we investigated the ion irradiation effects before and during the facet coating on 1.31 μm GaInAsP/InP DFB-LD. The increase of the surface recombination current and enhancement of the ESD induced degradation was observed by extending the ion irradiation time before the coating. And the ion irradiation during the coating did not affect the ESD degradation. These results indicate the facet condition before the coating is most important and the ion irradiation increases the surface recombination and accelerates the ESD induced degradation.