CMOS SPAD Sensors for 3D Time-of-Flight Imaging, LiDAR and Ultra-High Speed Cameras

In conventional applications, such as bio-imaging and microscopy, SPAD is typically used as a single-photon counter. However, this advantage has been challenged by other photon-counting technologies, especially from CMOS-based QIS. Comparatively, apart from single-photon counting capability, QIS is superior to SPAD in terms of intrinsic multi...

A CMOS SPAD Imager with Collision Detection and 128 Dynamically Reallocating TDCs for Single-Photon Counting and 3D Time-of-Flight Imaging

Per-pixel time-to-digital converter (TDC) architectures have been exploited by single-photon avalanche diode (SPAD) sensors to achieve high photon throughput, but at the expense of fill factor, pixel pitch and readout efficiency. In contrast, TDC sharing architecture usually features high fill factor at small pixel pitch and energy efficient...

High-Performance Back-Illuminated Three-Dimensional Stacked Single-Photon Avalanche Diode Implemented in 45-nm CMOS Technology

We present a high-performance back-illuminated three-dimensional stacked single-photon avalanche diode (SPAD), which is implemented in 45-nm CMOS technology for the first time. The SPAD is based on a P⁺/Deep N-well junction with a circular shape, for which N-well is intentionally excluded to achieve a wide depletion region, thus...