Noise and Breakdown Characterization of SPAD Detectors with Time-Gated Photon-Counting Operation

Being ready-to-detect over a certain portion of time makes the time-gated single-photon avalanche diode (SPAD) an attractive candidate for low-noise photon-counting applications. A careful SPAD noise and performance characterization, however, is critical to avoid time-consuming experimental optimization and redesign iterations for such applications. Here, we present an extensive empirical study of the breakdown voltage, as well as the dark-count and afterpulsing noise mechanisms for a fully integrated time-gated SPAD detector in 0.35-mu m CMOS based on experimental data acquired in a dark condition. An effective SPAD breakdown voltage is introduced to enable efficient characterization and modeling of the dark-count and afterpulsing probabilities with respect to the excess bias voltage and the gating duration time. The presented breakdown and noise models will allow for accurate modeling and optimization of SPAD-based detector designs, where the SPAD noise can impose severe trade-offs with speed and sensitivity as is shown via an example.

Automated summary

An empirical study on breakdown voltage, dark-count, and afterpulsing noise mechanisms of a fully integrated time-gated SPAD detector in 0.35μm CMOS was conducted based on experimental data acquired in dark conditions. An effective SPAD breakdown voltage was introduced to enable efficient characterization and modeling of dark-count and afterpulsing probabilities with respect to excess bias voltage and gating duration time. The presented breakdown and noise models will allow for accurate modeling and optimization of SPAD-based detector designs, showing potential trade-offs between noise, speed, and sensitivity.