Evaluation of size influence on performance figures of a single photon avalanche diode fabricated in a 180 nm standard CMOS technology

We present the performance characteristics of a single photon avalanche diode (SPAD) fabricated in a 180 nm standard CMOS image sensor technology. The SPAD structure was implemented in 8 different diameters between 5 and 40 μm to determine the influence of size variation on the SPAD performances in terms of dark count rate, afterpulsing, efficiency and time resolution. The measurements show a dark count rate below 10 kHz at 15 °C with a low afterpulsing probability (0.2 % at an excess bias of 300 mV), a good Photodetection efficiency (~20 %) and a very good time resolution (<70 ps FWHM at 450 nm) .