Timing Performance With Broadcom Metal Trench Silicon Photomultipliers

Abstract

Single photon time resolution (SPTR), photon detection efficiency (PDE), and correlated noise rate are important performance characteristics of modern silicon photomultipliers (SiPMs) in consideration of advances in time-of-flight positron emission tomography (TOF-PET). Commercially available Broadcom near-ultraviolet metal-trench (NUV-MT) SiPMs feature metal-filled trench technology to suppress optical crosstalk. We investigated the achievable SPTR and coincidence time resolution (CTR) of NUV-MT SiPMs with various sizes and scintillation crystals, employing low-noise high-frequency readout electronics. The achievable intrinsic SPTRs of $2\times 2$ , $4\times 4$ , and $6\times 6$ -mm2 devices were estimated using a picosecond-pulse laser setup. 2- and 4-mm SiPMs were coupled with $2\times 2\times 3$ mm3 and $3\times 3\times 20$ -mm3 LGSO and BGO crystals to assess achievable CTRs. The intrinsic SPTRs of 2-, 4-, and 6-mm SiPMs biased with 48 V were estimated to be 45, 55, and 137 ps in full width at half maximum (FWHM), respectively. The detector comprised a 2-mm SiPM and a $2\times 2\times 3$ -mm3 BGO achieved 111-ps CTR FWHM. The results demonstrated a significant influence of superior SPTR of 2-mm SiPM for the Cherenkov event portion compared to scintillation-based events. The suppressed noise of NUV-MT enabled stable operation at high-bias voltage, offering excellent SPTR and PDE for breakthroughs in the timing resolution of TOF-PET detectors.