In the 40nm Backside Illuminated (BSI) CMOS image sensor flow, the Backside Passivation IIP - Photo step defines the precise spatial boundaries for the subsequent ion implantation process T1.Following the meticulous pre-lithography cleaning of the oxide hard mask, this photolithography step applies and patterns a photoresist layer to act as an ion-blocking mask T1.The primary device physics objective of the downstream implant is to mitigate interface trap states at the thinned silicon surface, w