VIA 5 - Photo defines the vertical interconnects bridging Metal 5 and Metal 6 in the dual-damascene back-end-of-line (BEOL) stack T1.Coming immediately after the ILD 5-1 and ILD 5-2 depositions and a pre-litho clean, this step spatially defines the contact openings before pattern transfer into the underlying dielectric layers A2.The precise positioning of these vias is critical to establish low-resistance electrical connections for signal and power routing within the image sensor architecture (E