Single Photon Avalanche Diodes and Vertical Integration Process for a 3D Digital SiPM using Industrial Semiconductor Technologies

Single Photon Avalanche Diode (SPAD) and Silicon PhotoMultiplier (SiPM) are detectors of high interest in radiation instrumentation. They provide high sensitivity in the UV-visible range and sub-nanosecond timing resolution. Systems such as large area detectors in particle physics also require the detectors to be low noise, low cost and suitable for large scale integration. We report on a 3D vertically integrated digital SiPM process made with industrial semiconductor technologies. The 3D digital SiPM architecture integrates a SPAD array with CMOS electronics using exclusively industrial technologies to ensure large scale fabrication capability. Three main development runs are ongoing: the custom SPAD fabrication (Teledyne DALSA CCD foundry), the electronics readout integrated circuit design (TSMC CMOS 180 nm), and the wafer scale 3D integration (Teledyne DALSA MEMS foundry). This paper focuses on the SPAD design and the 3D process made inside Teledyne DALSA's facilities. First wafers from both the SPAD and 3D runs have been completed recently. We report on the characterization of those wafers. For the SPAD run, IV curves, dark noise, detection efficiency and timing resolution will be presented. For the 3D wafers, the studied aspects are the bonding strength, the uniformity and the interconnects electrical characteristics. The results will be discussed in the context of low background neutrino and dark matter physics experiments.