8×8 flipchip assembled InGaAs detector arrays for optical interconnect

The design and performance of detector arrays for optical interconnect are reported. These arrays consist of an InGaAs/InP heterostructure planar pin photodiode with optical access through the substrate. A selfaligned flipchip solder bond assembly process has been used to provide mechanical attachment and direct electrical connection to an electrical backplane or silicon integrated circuit. Arrays with up to 64 elements have been fabricated with mean dark current densities of 500 nA cm−2, with assembly yields in excess of 99.85% and submicrometre alignment accuracy.