STI-Bounded Single-Photon Avalanche Diode in a Deep-Submicrometer CMOS Technology

This letter presents a novel and compact CMOS Geiger-mode single-photon avalanche diode (SPAD) device with an efficient guard ring structure for preventing edge breakdown. The new guard ring can withstand considerably higher electric fields than existing structures, and results in pixels which are an order of magnitude smaller and offer a nine-fold increase in fill factor compared with existing SPADs. The device has been studied numerically and experimentally on a 0.18-mum CMOS technology. Due to its small area, the detector can be operated with minimal power dissipation and has been verified to operate reliably over 5times10¹⁰ cycles. This is the first SPAD proven in a deep-submicrometer non-high-voltage technology and as such, provides unique opportunities for improved performance and for on-chip integration of the ultrafast timing circuitry required to translate the SPAD output into meaningful data