The Metal 1 Gate, S/D Contact Opening - Photo step serves as the critical photolithography process to define vertical electrical pathways from the first primary routing metal (Metal 1) down to the transistor gate and active source/drain regions A2.Positioned immediately after PMD 4 deposition and surface preparation, this step dictates the exact lateral spatial coordinates for the subsequent multi-layer dielectric etch through PMD 4, 3, and 2 A2.These contacts are essential to bridge the semicon