Design and Characterization of a Silicon Photomultiplier in 0.35- ${\mu }\text{m}$ CMOS

The possibility to design a silicon photomultiplier (SiPM) using standard CMOS processes represents the frontier of current low photon flux detectors. It allows an integrated development of both sensor and intelligent read-out electronics on the same technology line and enables to create intelligent devices with on-chip signal processing. We report the design and characterization of an SiPM composed of
$20\times 20$
microcells with size
$50\times 50 ~\mu \text{m}^{2}$
. The device exhibits 200-kHz/mm
²
dark rate, 10% cross talk probability, 1.5% afterpulsing probability, and
$5.35\times 10^{6}$
intrinsic gain at 29-V operational voltage. It is obtained at a 0.35-
$\mu \text{m}$
CMOS technology node, which is compatible with the development of integrated electronics. In order to verify the potential application of the device to optical and radiation detection systems, we measure its photon detection efficiency and its response to LED light and scintillation light from an LySO crystal.