Following the ILD 6-1 and 6-2 etch and subsequent ashing and clean steps, the dielectric trenches and vias are fully exposed and require metallization A2.The Ta-based liner deposition step serves as the critical interface between the inter-metal dielectric (IMD) and the highly conductive copper interconnect P2.Specifically, this step in the DBI (Direct Bond Interconnect) module prepares the Metal 6 layer for copper seed deposition and subsequent bulk electrochemical fill A2.This specific step di