The Light Shield (LS) Backside Contact IIP (Ion Implantation) step follows the backside silicon etch and precedes the deposition of the light shield grid and barrier metals A1.In BSI CMOS Image Sensors, forming a reliable electrical connection to the backside substrate is critical for establishing a stable reference potential and mitigating electrical crosstalk (Engineering Practice).The ion implantation process introduces precisely controlled dopants into the exposed silicon, altering the local