This stacked, direct time-of-flight (dToF) SPAD Depth Sensor for automotive LiDAR uses single photon avalanche diode (SPAD) pixels. By stacking SPAD pixels and distance-measuring processing circuits into a single chip, distances of up to 300 M can be measured at 15-cm resolution with high accuracy and high speed.
Sony's Imaging and Sensing Technologies announced the upcoming release of the IMX459 stacked SPAD depth sensor, which combines a 10 μm2 SPAD with a distance-measuring processing circuit in a single chip that fits into a compact 1/2.9-type form factor. It has an effective resolution of 100,000 pixels. The sensor targets LiDAR applications such as advanced driver-assistance systems (ADAS) and autonomous driving.
The chip leverages Sony technologies that include a back-illuminated pixel structure, stacked configurations, and Cu-Cu (copper) connections.The Cu pads are used to stack the pixel section (top chip) and logic circuits (bottom chip). This method gives the chip designers more freedom and improves productivity, allows for a more compact size, and increases performance compared to through-silicon via (TSV) wiring. The Cu connection is achieved by electrodes intruded around the circumference of the pixel area.