A Backside-Illuminated Charge-Focusing Silicon SPAD With Enhanced Near-Infrared Sensitivity

A backside-illuminated (BSI) near-infrared (NIR)-enhanced silicon single-photon avalanche diode (SPAD) for time-of-flight (ToF) light detection and ranging applications is presented. The detector contains a 2- $\boldsymbol {\mu }\text{m}$ -wide multiplication region with spherically uniform electric field peak enforced by field-line crowding. charge-focusing extends into 10- -deep absorption volume, whereby electrons generated in all the corners of device can move efficiently toward region. SPAD integrated customized 130-nm CMOS technology dedicated BSI process. has pitch notation="LaTeX">$15 \boldsymbol , which potential to be scaled down without significant performance loss. Furthermore, achieves photon efficiency (PDE) 27% at 905 nm, an excess bias 3.5 V that controlled electronics, timing resolution 240 ps. By virtue these features, architecture well-suited large-format ToF imaging arrays electronics.