The Ashing & Strip/Clean step in the Via 2 (V2) module is a critical post-etch operation directly following the ILD 2-1 SiCN breakthrough etch A2.The upstream reactive ion etch (RIE) utilizes fluorocarbon-based plasmas to selectively remove the SiCN barrier, which invariably leaves behind heavily crosslinked fluoropolymer residues and remaining photoresist or hardmask materials P2.This specific cleaning step is distinct from other routine strip operations in the flow because it must address comp