Experimental Study of a Large Area High PDE SiPM in 0.11-μm CMOS Process for PET Applications

Silicon photomultipliers (SiPMs) fabricated in a standard complementary metal-oxide-semiconductor (CMOS) process enable the development of cost-effective, reliable, and power-efficient photosensors for positron emission tomography (PET) applications. However, PET manufacturers prefer SiPMs in customized technologies for their high photon detection efficiency (PDE) and low noise, which are crucial parameters for energy and time resolution in PET scanners. Recently, RAYQUANT Technology Ltd. has developed a high PDE SiPM fabricated in 0.11- $\mu $ m CMOS process, with large area of 9 mm2. This article investigates for the first time the ability of this SiPM to collect scintillation light from LYSO crystals for PET applications, evaluating energy resolution, and coincidence time resolution (CTR). The LYSO/SiPM detector achieves the best energy resolution (FWHM) of $\mathbf {(28. 0\pm 1.0)}$ % at 60 keV, $\mathbf {(10.6\pm 0.4)}$ % at 511 keV, and $\mathbf {(8.5\pm 0.4)}$ % at 662 keV. The best CTR (FWHM) is $\mathbf {(172\pm 2)}$ ps, $\mathbf {(147\pm 2)}$ ps, and $\mathbf {(115\pm 1)}$ ps, when the SiPM is coupled to crystals of 20, 10, and 5 mm length, respectively. These results confirm that the studied CMOS-based SiPM is not only suitable for PET applications but is even competitive with SiPMs fabricated in customized technologies.