Infrared vertically-illuminated photodiode for chip alignment feedback
  We report on vertically-illuminated photodiodes fabricated in the GlobalFoundries 45nm 12SOI node and on a packaging concept for optically-interconnected chips. The photodiodes are responsive at 1180 nm, a wavelength currently used in chip-to-chip communications. They have further a wide field-of-view which enables chip-to-board positional feedback in chip-board assemblies. Monolithic integration enables on-chip processing of the positional data. 
Luca Alloatti, Rajeev Jagga Ram
physics.ins-det physics.optics