Defect passivation and dark count in Geiger mode avalanche photodiodes
J. C. Jackson, G. Healy, P. K. Hurley, A-M. Kelleher, J. Alderman, A. P. Morrison and A. Mathewson

In Proceedings: IEEE IRPS, International Reliability Physics Symposium, Dallas, Texas
Month: April
Year: 2003

Abstract
An experimental study of post metal anneal conditions on dark count in Geiger-mode avalanche photodiodes (GM-APD) has been performed. The GM-APD structure will be shown to be extremely sensitive to post-metal anneals. Dark counts from measured samples decreased by a factor of two for each separate anneal in forming gas using temperatures from 425 C to 450 C. Conversely anneals of 250 C in ambient increased dark count for temperature cycles up to 124 hours. Passivation and de-passivation of defect sites within the shallow junction active area are suspected as mechanisms contributing to the variations in dark count.