A 336 x 240 Backside-Illuminated 3D-Stacked 7μm SPAD for LiDAR Sensor with PDE 28% at 940nm and under 0.4% Depth Accuracy Up to 10m

Single photon avalanche diode (SPAD) is a key technology in light detection and ranging (LiDAR) sensors, which are gaining prominence as next-generation image sensors. We designed SPAD with high photon detection efficiency (PDE) using a backside-illuminated hybrid bonding 3D-stacked technology. This is aimed at developing a LiDAR sensor with good depth accuracy. We achieved a PDE of 28% at $\lambda= 940\text{nm}$ and a low-level dark count rate (DCR) by applying the trench guide (TG) and the small lens array (SLA) structure and optimizing pixel design. As a result, we achieved a depth accuracy of less than 0.4% up to 10m.