Silicon Photomultipliers Technology at Fondazione Bruno Kessler and 3D Integration Perspectives

Single-photon avalanche diodes and Silicon photomultipliers are single-photon sensitive solid-state detectors that are garnering a growing interest in several applications, like as medical and biological imaging, high-energy physics experiments, spectroscopy and light detection and ranging systems. In recent years, three-dimensional integration technologies and backside illumination have been a real game changer in the field of CMOS Image Sensors, allowing to reach an ultra-high integration density and enhancing at the same time the overall sensor performances. In this work, we present the custom technology developed at Fondazione Bruno Kessler (Trento, Italy) for single-photons diodes and silicon photomultipliers, describing the performance of such devices in terms of their main figures of merit. We illustrate different 3D integration schemes aimed at interconnecting current analog silicon photomultipliers to a digital read-out electronics, by exploiting the most recent 3D interconnecting technologies available on the market. We discuss all the potential benefits and the key technological aspects of the resulting novel schemes.