Epitaxial silicon single photon detector with reduced carrier diffusion effect and picosecond resolution

Single-photon avalanche diodes SPADs are devices with uniform breakdown, operating above the breakdown voltage in the triggered avalanche mode. In this work, two different epitaxial device structures were designed and experimented. The slow component of the time resolution function, due to the diffusion of photogenerated carriers, was strongly reduced. The dependence of the fast component on the breakdown electric field and on the excess bias was investigated. Time resolutions down to 45 picoseconds (full width at half maximum) were obtained.