Guarding for a CMOS photosensor chip

摘要

In a CMOS-based photosensor chip, the area between the last photosensor in a linear array of photosensors and the edge of the chip can be a source of unintended charge generation affecting the last photosensor. A guardring, in the form of a biased diffusion area, prevents the unwanted leakage of charge from the edge area to the end photosensor.