Cross-talk and RTS Noise Characterization of 1- and 2-tier CMOS SPADs in a 150 nm Process

This paper presents the results from the characterization of single-tier and dual-tier single photon avalanche diode (SPAD) arrays fabricated in a 150 nm CMOS technology. The chips under test contain SPADs with different size and active area and different avalanche quenching network, either passive or active. The tests were focused on the measurement of the dark count rate, with emphasis on the effects of optical cross-talk, in different operating conditions. Random telegraph signal (RTS) fluctuations in the dark count rate, and their dependence on the SPAD bias voltage, were also investigated.