The PMD 4 Oxide Etch step acts as a critical pattern transfer mechanism within the transition from the Middle-of-Line (MOL) to the Back-End-of-Line (BEOL) interconnect architecture A1.Following the preliminary PMD 5 Oxide Etch, this step continues etching through the pre-metal dielectric stack to define the exact geometry of the Metal 1 (MET1) trenches or contacts A1.As semiconductor technologies scale down to deep submicron nodes, interconnect resistance-capacitance (RC) delay transitions from