Design improvement and characterization of SOI-based silicon-photomultiplier prototype

We designed and fabricated six new silicon-on-insulator silicon-photomultiplier (SOI-SiPM) prototypes with a SOI CMOS using 200-nm integrated-process technology. Each prototype consisted of sixty-four 30-μm microcells but had a different combination of quenching resistance (100 or 200 kΩ), cathode size, and guard-ring size. The observed breakdown voltage was 20.5–21.9 V with an operation range of 2.6–3.8 V; the measured gain was approximately 1–3 × 105. The measured time resolution with full excitation was 22.7 ps (FWHM); the single-photon time resolution was 246.3 ps. The photon spectrum showed clear photon-counting capability and the photo-detection efficiency was 8.1% (a four-fold improvement from the previous prototype). These results suggest that SOI-SiPM can be employed in a fully integrated monolithic pixel photon detector, which would be a useful sensor for positron emission tomography, Compton camera, or photon-timing applications.