After the ILD 5-2 Oxide Etch forms the MET6 trench in the low-k dielectric, the photoresist mask must be completely removed before metallization A1.This ashing step serves as the primary organic removal process, transitioning the wafer from dielectric patterning to the preparation phase for Ta-based liner and Cu seed deposition T2.If the resist is not completely removed, subsequent Ta-liner deposition will suffer from poor adhesion and high contact resistance P2.Therefore, ashing must efficientl