Apparatus and method for single-photon avalanche-photodiode detectors with reduced dark count rate

An avalanche photodiode comprising:

• a first diffused region of a first diffusion type;
• the first diffused region overlying at least in part a second diffused region of a second diffusion type;
• and
• a first minority carrier sink region disposed within the first diffused region, the first minority carrier sink region being of the second diffusion type;
• further comprising a second minority carrier sink region, disposed within the second diffused region, the second minority carrier sink region being of the first diffusion type, and electrically connected to the second diffused region;
• wherein the first and second diffused regions are configured such that a depletion zone having avalanche multiplication characteristics forms between the first diffused region and the second diffused region when under bias;
• wherein the first minority carrier sink region is electrically connected to the first diffused region.

A method of detecting photons comprising:

• providing a reverse bias to an avalanche photodiode having an N region and a P region, and thereby forming a depletion zone between the N region and P region;
• attracting minority carriers to a P-type first minority carrier sink from portions of the N region opposite the depletion zone and attracting minority carriers to an N-type second minority carrier sink from the P region opposite the depletion zone;
• receiving photons and forming carrier pairs;
• amplifying the carrier pairs in the depletion zone to produce a detectable current-flow;
• quenching current flow;
• and
• re-biasing the N and P regions.

A method of detecting photons comprising:

• providing a reverse bias to an avalanche photodiode having an N region and a P region, and thereby forming a depletion zone between the N region and P region;
• attracting minority carriers to minority carrier sinks from portions of the N region and the P region opposite the depletion zone;
• receiving photons and forming carrier pairs;
• amplifying the carrier pairs in the depletion zone to produce a detectable current-flow;
• quenching current flow;
• and
• re-biasing the N and P regions;
• wherein a first minority carrier sink is a shallow P type region embedded in the N region of the photodiode, the first minority carrier sink is electrically connected to the N region of the photodiode and embedded in a portion of the N region of the photodiode opposite from the depletion zone;
• and
• wherein a second minority carrier sink is an N-type region embedded in the P region of the photodiode.