A Passive-Quenching Active-Recharge analog Silicon Photomultiplier

In this work, we propose a new analog SiPM structure, characterized by the Passive Quenching Active Recharge operation of the microcells. The structure is obtained by including a MOSFET transistor close to each cell. The transistor is built without any changes to the standard SiPM micro-fabrication process and it does not significantly reduce the fill-factor of the device. We operated this detector in a periodic pulsed reset mode. Potential advantages of this approach are: reduction of the effective Dark Count Rate, strong suppression of the afterpulsing, very short pulse duration, lower fabrication cost. In this paper, we provide a preliminary characterization of the first 1×1 mm² prototype of the structure, with 50×50 μm² cells, fabricated at FBK. The measured duration of the single-cell response is 3.4 ns FWHM. Using a pulsed LED source, we were able to measure a very good photon counting resolution at a level of 18 detected photons and more, thanks to the absence of after pulses.