Resonant-cavity-enhanced single-photon avalanche diodes on double silicon-on-insulator substrates

We report the first resonant-cavity-enhanced single photon avalanche diode (RCE SPAD) fabricated on a reflecting silicon-on-insulator (SOI) substrate. The substrate incorporates a two period distributed Bragg reflector fabricated using a commercially available double SOI process. The RCE SPAD detectors have peak photon detection efficiencies ranging from 42% at 780nm to 34% at 850nm and an excellent photon timing resolution of 35 ps full width at half maximum. Despite the higher defectivity of double SOI substrates compared to standard silicon substrates, RCE SPADs with 20 µm diameter exhibit a fairly low dark count rate (DCR) of 3500 c/s at room temperature and a yield of 80%. A DCR less than 50 c/s can be attained with these detectors by reducing the temperature down to -15 °C, while keeping the total afterpulsing probability below 9% with a dead-time of 80 ns.