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CMOS single-photon avalanche diodes (SPADs) have broken into the mainstream by enabling the adoption of imaging, timing, and security technologies in a variety of applications within the consumer, medical and industrial domains. The continued scaling of technology nodes creates many benefits but also obstacles for SPAD-based systems. Maintaining and/or improving upon the high-sensitivity, low-noise, and timing performance of demonstrated SPADs in custom technologies or well-established CMOS image sensor processes remains a challenge. In this paper, we present SPADs based on DPW/BNW junctions in a standard Bipolar-CMOS-DMOS (BCD) technology with results comparable to the state-of-the-art in terms of sensitivity and noise in a deep sub-micron process. Technology CAD (TCAD) simulations demonstrate the improved PDP with the simple addition of a single existing implant, which allows for an engineered performance without modifications to the process. The result is an 8.8 µm diameter SPAD exhibiting ∼2.6 cps/µm 2 DCR at 20 • C with 7 V excess bias. The improved structure obtains a PDP of 62 % and ∼4.2 % at 530 nm and 940 nm, respectively. Afterpulsing probability is ∼0.97 % and the timing response is 52 ps FWHM when measured with integrated passive quench/active recharge circuitry at 3V excess bias. Index Terms-Single-photon avalanche diodes (SPADs), Photon counting, depth-sensing, BCD, time-correlated single-photon counting(TCSPC), LIDAR, three-dimensional (3-D) ranging, FLIM, QRNG I. INTRODUCTION L ARGE-FORMAT single-photon avalanche diode (SPAD) arrays [1]-[3] are becoming ubiquitous in the timeresolved imaging domain for their utility in applications such as fluorescence lifetime imaging microscopy (FLIM),

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The radiation hardness of 180 nm complementary metal–oxide–semiconductor (CMOS) and 55 nm bipolar–CMOS–double-diffused MOS single-photon avalanche diodes (SPADs) is studied using 10 MeV and 100 MeV protons up to a displacement damage dose of 1 PeV/g. It is found that the dark count rate (DCR) levels are dependent on the number and the type of defects created. A new stepwise increase in the DCR is presented. Afterpulsing was found to be a significant contributor to the observed DCR increase. A new model for DCR increase prediction is proposed considering afterpulsing. Most of the samples under test retain reasonable DCR levels after irradiation, showing high tolerance to ionizing and displacement damage caused by protons. Following irradiation, self-healing was observed at room temperature. Furthermore, high-temperature annealing shows potential for accelerating recovery. Overall, the results show the suitability of SPADs as optical detectors for long-term space missions or as detectors for high-energy particles.

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