Long-Lived (GaAl)As DH Lasers Bonded with In Produced by Eliminating Deterioration of In Solder

Abstract
Long-lived (GaAl)As DH lasers bonded with In solder have been produced using Mo as a barrier metal. The amount of Au on the Mo was reduced to much less than the amount of In solder to eliminate the deterioration of the latter. The intermetallic formation between In and Au was investigated using a simulation method. An accelerated reliability test at 50 and 70°C, gave the activation energy of degradation as 0.52 eV. The mean time required for a 50 mA driving current increase in these long-lived devices was estimated to be 1.9×106 hours at 25°C in operation at 5 mW/facet.