Improvements in electrostatic discharge performance of InGaAsP semiconductor lasers by facet passivation

Chemically treating laser facets with aqueous sulfides can significantly improve the electrostatic discharge (ESD) performance of InGaAsP semiconductor lasers. Commercial lasers free of internal defects were subjected to forward-biased Human Body Model ESD stress pulses. Devices passivated with sulfides exhibited a mean ESD failure voltage more than 400% higher than that of the untreated control group. Subsequent accelerated aging experiments suggest that a thick layer of oxide covering the laser facets, largely removed by the sulfide treatment, is responsible for the low ESD failure voltage on untreated devices. This suggests that sulfide passivation followed by facet encapsulation in a robust dielectric could result in permanent protection against ESD failure