Reliability of InGaAs/InP based separate absorption grading multiplication avalanche photodiodes

An overview over typical defects and reliability aspects regarding the operation of InGaAs/lnP avalanche photodiodes for the use in fiberoptic communication systems is given. Measurements regarding the performance and stability of different types of top illuminated InGaAs/lnP Separate Absorption Grading Multiplication avalanche photodiodes have been compared with special emphasis on the homogeneity of the photoresponse. High resolution scanning optical microscopy measurements at different wavelengths allowed to identify specific technological problems. Guard ring misalignment resulting in increased responsivity of the junction perimeter have been found on devices from one manufacturer. The responsivity images of the active area of some of the investigated photodiodes showed sharp peaks due to microplasma formation. The impact of these microplasmas on dark current and photocurrent of the devices has been investigated in detail. A step-stress test performed at successively increasing temperatures resulted in the catastrophic failure of the tested devices from one family. An analysis of the dark current-voltage characteristics before and after degradation leads to the conclusion that a modification of the semiconductor-insulator interface properties caused a dramatic increase in the surface leakage currents. Copyright (C) 1996 Elsevier Science Ltd.