Characterization of small single photon avalanche diode fabricated using standard 180 nm CMOS process for digital SiPM

• Published in: Nuclear engineering and technology Vol. 56; no. 8; pp. 3076 - 3083
• Main Authors: Oh, Jinseok, Jeong, Hakcheon, Lee, Min Sun, Kwon, Inyong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2024; Elsevier; 한국원자력학회
• Subjects: Breakdown voltage; Dark count rate (DCR); Depletion region; Guard ring; On-chip sensor; Photon detection probability (PDP); Premature edge breakdown (PEB); Single photon avalanche diodes (SPADs); Standard CMOS; 원자력공학; Breakdown voltage; Guard ring; Single photon avalanche diodes (SPADs); Depletion region; Standard CMOS; Premature edge breakdown (PEB); Dark count rate (DCR); On-chip sensor; Photon detection probability (PDP)
• ISSN: 1738-5733; 2234-358X; 2234-358X
• DOI: 10.1016/j.net.2024.03.006

In this work, single photon avalanche diodes (SPADs) were fabricated using the standard 180 nm complementary metal-oxide semiconductor process. Their small size of 15–16 μ m and low operating voltage made it possible to easily integrate them with readout circuits for compact on-chip sensors, particularly those used in the radiation sensor network of a nuclear plant. Four architectures were proposed for the SPADs, with a shallow trench isolation (STI) guard ring and different depletion regions designed to demonstrate the main performance parameters in each experimental configuration. The wide absorption region structure with PSD and a deep N-well could achieve a uniform electric field, resulting in a stable dark count rate (DCR). Additionally, the STI guard ring was implanted to mitigate the premature edge breakdown. A breakdown voltage was achieved for a low operating voltage of 10.75 V. The DCR results showed 286.3 Hz per μm2 at an excess voltage of 0.04 V. A photon detection probability of 21.48% was obtained at 405 nm.