Following the Oxide Grid Seal Layer Etch, the deep high-aspect-ratio trenches are coated with highly crosslinked fluorocarbon (CFx) polymers intentionally deposited for sidewall passivation, alongside hardened photoresist remnants P1.If left intact, these residues will prevent the conformal deposition of the Lower Vertical Grid Barrier layer, leading to adhesion failure or structural voids that severely compromise the pixel's optical isolation P2.Therefore, this specific Ashing & Strip/Clean ste