Avalanche Breakdown Timing Statistics for Silicon Single Photon Avalanche Diodes

Silicon-based single photon avalanche diodes (SPADs) are widely used as single photon detectors of visible and near infrared photons. There has, however, been a lack of models accurately interpreting the physics of impact ionization (the mechanism behind avalanche breakdown) for these devices. In this paper, we present a statistical simulation model for silicon SPADs that is capable of predicting breakdown probability, mean time to breakdown, and timing jitter. Our model inherently incorporates carriers' dead space due to phonon scattering and allows for nonuniform electric fields. Model validation included avalanche gain, excess noise factor, breakdown voltage, breakdown probability, and timing statistics. Simulating an n-on-p and a p-on-n SPAD design using our model, we found that the n-on-p design offers significantly improved mean time to breakdown and timing jitter characteristics. For a breakdown probability of 0.5, mean time to breakdown and timing jitter from the n-on-p design were 3 and 4 times smaller compared to those from the p-on-n design. The data reported in this paper are available from the ORDA digital repository (DOI: 10.15131/shef.data.4823248).