Reliability of mesa and planar InGaAs PIN photodiodes

InGaAs planar-structure PIN photo-diodes fabricated from MOVPE material have been demonstrated to have outstanding reliability. The predicted random failure rate at 20°C is less than 0.3 FITs, and the mean time to failure is estimated to be 1011 hours at 20°C. By contrast, the reliability of mesa-structure photodiodes is unacceptable because of an instability of the dark current. A similar kind of instability has been observed in commercially available mesa photodiodes. Extensive life testing of planar-structure and mesa-structure PINs made by several manufacturers shows that the reliability of mesa-structure PINs is inferior in all cases.