Patent ID: 8836066

Claim:
An avalanche photodiode, comprising: silicon crystal doped with impurities, wherein the doping profile of the silicon crystal comprises a smoothly arcing donor-acceptor concentration curve decreasing with respect to distance into the interior of the silicon crystal that is interrupted by a narrower peak of increased concentration in the interior of the silicon crystal prior to further decreasing with respect to distance along the smoothly arcing donor-acceptor concentration curve, wherein the doping profile is between 10 15 and 10 16 donor-acceptor concentration per square meter at the surface of the silicon crystal and decreases to less than 10 10 donor-acceptor concentration per square meter at a distance of less than 5×10 −7 meters into the interior of the silicon crystal, wherein the ionization ratio of the avalanche photodiode is 0.02 or less.