In Backside Illumination (BSI) CMOS Image Sensors, thinning the silicon wafer exposes the backside epitaxial layer, creating a physical boundary heavily populated with dangling bonds and crystalline defects T1.These interface defects act as generation-recombination centers that severely increase dark current and degrade the signal-to-noise ratio of the sensor P5.The Back Passivation Ion Implantation (IIP) step addresses this by introducing acceptor dopants into the backside silicon surface to fo