Abstract: A photodiode and method of forming a photodiode has a substrate. An absorption layer is formed on the substrate to absorb lightwaves of a desired frequency range. A multiplication structure is formed on the absorption layer. The multiplication layer uses a low dark current avalanching material. The absorption layer and the multiplication layer are formed into at least one mesa having in an inverted “T” configuration to reduce junction area between the absorption layer and the multiplication layer. A dielectric layer is formed over the at least one mesa. At least one contact is formed on the dielectric layer and coupled to the at least one mesa.

Abstract: A metamorphic avalanche photodetector includes a substrate, and an active structure supported on the substrate. The active structure has a metamorphic absorption structure that absorbs light and responsively produces primary charge carriers, and an avalanche multiplication structure that receives the primary charge carriers from the metamorphic absorption structure and responsively produces secondary charge carriers. An output electrical contact is in electrical communication with the active structure to collect at least some of the secondary charge carriers. A buffer layer lies between the substrate and the active structure, between the active structure and the output electrical contact, or between the metamorphic absorption structure and the avalanche multiplication structure. A lattice parameter of the buffer layer varies with position through a thickness of the buffer layer.

Abstract: An integrated fiber alignment photodetector is provided by forming a plurality of photodiodes on a first substrate. A corresponding plurality of through holes are formed in a second substrate, which is then aligned to the first substrate and bonded thereto to form a fiber alignment photodetector assembly. Individual fiber alignment photodiodes may then be diced from the assembly. The through hole on each individual fiber alignment photodiode provides a guide for the insertion of an optical fiber, which may then be bonded within the through hole to complete a fiber alignment photodetector.

Abstract: An avalanche photodiode having a reduced capacitance is provided. The avalanche photodiode includes a wide band gap layer in its depletion region. The width of the wide band gap layer increases the extent of the depletion region, thereby reducing the capacitance while minimizing the impact on the dark current.