Segmented Digital SiPM

Abstract

A digital silicon photomultiplier (SiPM) using segmentation technique is designed, simulated and fabricated in the AMS 0.35 µm SiGe BiCMOS process. The digital SiPM is intended for photon counting applications. The digital SiPM consists of 16 avalanche photodiodes (APD) each with active area of 24 µm x 24 µm arranged in a 4x4 array with series 236 kΩ quench resistors. The SiPM has a peak responsivity at 490 nm wavelength and a fill factor of 12.6 %. The digital SiPM generates an output 5-bit digital word that indicates the number of APDs triggered in the SiPM array at the rising edge of clock. Simulation results show that the digital SiPM can work at a maximum speed of 100 MS/s and uses 64.6 mW of power. The digital SiPM occupies an area of 0.38 mm2.