Double-mesa thin-film reach-through silicon avalanche photodiodes with large gain-bandwidth product

Design criteria for a broadband high gain-bandwidth-product silicon avalanche photodiode are given. The structure and fabrication steps of a diode are presented, which meet these criteria. It is a thin-silicon-film structure, which uses a highly reflecting back contact to increase the internal quantum efficiency. The temporal and wavelength response are given. The measurements confirm the expected excellent characteristic.