In this paper, we investigated the discrete switching of the Dark Count Rate between two or more levels in Single-Photon Avalanche Diode devices. This phenomenon, known as Random Telegraph Signal, is related to the density and distribution of defects in the semiconductor lattice and oxides. In this paper, we focused on a test chip containing SPADs with different architectures designed and implemented in 150-nm CMOS technology. The occurrence probability of the Random Telegraph Signal for proton-irradiated devices has been measured as a function of temperature for different SPAD layouts.

1. S. Cova, A. Longoni, and A. Andreoni, “Towards Picosecond Resolution with Single-Photon Avalanche Diodes,” Rev. Sci. Instr.,vol. 52, no. 3, pp. 408 – 412, Mar. 1981.
   DOI: 10.1063/1.1136594
2. M. M. Ter-Pogossian, N. A. Mullani, D. C. Ficke, J. Markham, D. L. Snyder, “Photon time-of-flight-assisted positron emission tomography,” J. Comput. Assist. Tomogr., vol.5, no. 2, pp. 227 – 239, Apr. 1981.
   DOI: 10.1097/00004728-198104000-00014
   PMid: 6971303
3. E. Schaefer, “Search for gamma ray burst counterparts,” in Proc. AIP Conf. Gamma-ray burstr: Second Workshop (AIP 307), Huntsville (AL), USA, 1993.
   DOI: 10.1063/1.45900
4. D. Bronzi et al., “100 000 frames/s 64 °ø 32 single-photon detector array for 2-D imaging and 3-D ranging,” IEEE J. Sel. Topics Quantum Electron., vol. 20, no. 6, 3804310, Nov-Dec. 2014.
   DOI: 10.1109/JSTQE.2014.2341562
5. S. Cova et al., “Avalanche photodiodes and quenching circuits for single-photon detection,” Appl. Opt., vol. 35, no. 12, pp. 1956 – 1976, Apr. 1996.
   DOI: 10.1364/AO.35.001956
6. A. Rochas et al., “Low-noise silicon avalanche photodiodes fabricated in conventional CMOS technologies,” IEEE Trans. Electron Devices, vol. 49, no. 3, pp. 387 – 394, Mar. 2002.
   DOI: 10.1109/16.987107
7. J. A. Richardson, E. A. G. Webster, L. A. Grant, R. K. Henderson, “Scaleable Single-Photon Avalanche Diode Structures in Nanometer CMOS Technology,” IEEE Trans. Electron Devices,vol. 58, no. 7, pp. 2028 – 2035, Jul. 2011.
   DOI: 10.1109/TED.2011.2141138
8. L. Carrara, C. Niclass, N. Scheidegger, H. Shea, E. Charbon, “A Gamma. X-Ray and High-Energy Proton Radiation-Tolerant CIS for Space Applications,”in Proc. Solid-State Circuits Conference (ISSCC 2009), San Francisco (CA), USA, 2009.
   DOI: 10.1109/ISSCC.2009.4977297
9. L. Carrara, M. Fishburn, C. Niclass, N. Scheidegger, H. Shea, E. Charbon, “A Variable Dynamic Range Single-Photon Imager Designed for Multi-Radiation Tolerance,” in Proc. EOS Frontiers in Electronic Imaging – Single-photon Imaging, Munich, Germany, Jun. 2009.
   Retrieved from: https://www.researchgate.net/publication/41939451_A_Variable_Dynamic_Range_Single-Photon_Image r_Designed_for_Multi-Radiation_Tolerance;
   Retrieved on: Apr. 3, 2018
10. I. H. Hopkins, G. R. Hopkinson, “Random telegraph signals from proton-irradiated CCDs,” IEEE Trans. Nucl. Sci. vol. 40, no. 6, pp. 1567 – 1574, Dec. 1993.
    DOI: 10.1109/23.273552
11. I. H. Hopkins, G. R. Hopkinson, “Further measurements of random telegraph signals in proton-irradiated CCDs,” IEEE Trans. Nucl. Sci.,vol. 42, no. 6, pp. 2074 – 2081, Dec. 1995.
    DOI: 10.1109/23.489255
12. G. R. Hopkinson, V. Goiffon, A. Mohammadzadeh, “Random telegraph signals in proton irradiated CCDs and APS,” IEEE Trans. Nucl. Sci., vol. 55, no. 4, pp. 2197 – 2204, Aug. 2008.
    DOI: 10.1109/TNS.2008.2000764
13. J. Bogaerts, B. Dierickx, R. Mertens, “Random telegraph signals in a radiation-hardened CMOS active pixel sensor,” IEEE Trans. Nucl. Sci., vol. 49, no. 1, pp. 249–257, Feb. 2002.
    DOI: 10.1109/TNS.2002.998649
14. C. Virmontois et al., “Dark Current Random Telegraph Signals in Solid-State Image Sensors,” IEEE Trans. Nucl. Sci., vol. 60, no. 6, pp. 4323 – 4331, Dec. 2013. DOI: 10.1109/TNS.2013.2290236
15. M. A. Karami, L. Carrara, C. Niclass, M. Fishburn, E. Charbon, “RTS Noise Characterization in Single-Photon Avalanche Diodes,” IEEE Electon Dev. Lett.,vol. 31, no. 7, pp. 692 – 694, Jul. 2010.
    DOI: 10.1109/LED.2010.2047234
16. F. Di Capua et al., “Random Telegraph Signal in Proton Irradiated Single-PhotonAvalanche Diodes,” IEEE Trans. Nucl. Sci., vol. 65, n0. 8, pp. 1654 – 1660, Aug. 2018.
    DOI: 10.1109/TNS.2018.2814823
17. L. Pancheri, D. Stoppa, “Low-noise Single-Photon Avalanche Diode in 0.15 µm CMOS Technology,” in Proc. European Conf., Solid-State Device Research (ESSDERC), Helsinki, Finland,2011, pp. 179 – 182.
    DOI: 10.1109/ESSDERC.2011.6044205
18. H. Xu, L. Pancheri, L. H. C. Braga, G. Dalla Betta, D. Stoppa, “Cross-talk characterization of dense single-photon avalanche diode arrays in CMOS 150-nm technology,” Opt. Eng., vol.55, no. 6, 067102, 2016.
    DOI: 10.1117/1.OE.55.6.067102
19. Ashland™ Gafchromic radiotherapy films, Ashland Advanced Materials, Bridgewater (NJ), USA, 2017.
    Retrieved from: http://www.gafchromic.com/gafchromic-film/radiotherapy-films/EBT/index.asp;
    Retrieved on: Jun. 14, 2018
20. M. Campajola, “Noise characterization of Single-Photon Avalanche Diodes,” M.Sc. dissertation, University “Federico II”, Dept. of Physics, Naples, Italy, 2017.
21. M. J. Kirton, M. J. Uren, “Noise in solid-state microstructures: a new perspective on individual defects, interface states, and low-frequency (1/f) noise,” Adv. Phys., vol. 38, no. 4, pp. 367 – 468, 1989.
    DOI: 10.1080/00018738900101122
22. G. D. Watkins, J. W. Corbett, “Defects in irradiatedsilicon: electron paramagnetic resonance and electron-nuclear double resonance of the Si-E center,” Phys. Rev., vol.134, no. 5A, pp. 1359 – 1377, Jun. 1964.
    DOI: 10.1103/PhysRev.134.A1359