Highly reliable operation of InGaAlAs mesa-waveguide photodiodes in humid ambient

摘要

Reliability of InGaAlAs mesa-waveguide photodiodes suitable for low-cost surface integration modules applied to access network systems is investigated. A passivation technique including silicone-based polymer encapuslation was used to ensure high reliability. Under a non-humidity condition of 200 deg C/10 V, a 9,600-hour stable operation was observed, and the estimated median lifetime is more than 100 years at the field service temperature of 85 deg C. A measured slight change in the dark current is explained in terms of hole accumulation at the semiconductor-insulator interface. Under a humid condition of 85 deg C/85percent RH/10V, there was no change in the dark current over 10,000 hours. The observed median lifetime at 135 deg C/85percent RH/10 V of 1,500 hours would lead to an estimated median lifetime at 45 deg C/50percent RH of about 50 years. These results suggest that the WG-PD is applicable to low-cost non-hermetic optical modules for optical access networks.