DuPont EKC265 Post Etch Residue Remover has been available for many years as post reactive ion etch photo-resist etchant for semiconductor wafer processing. It has also proven useful for the physical analysis of failing semiconductor devices. This paper shows how EKC265 can be used as copper metallization wet etchant to aid in the physical deprocessing. It provides the EKC265 copper metallization etch results and physical deprocessing results using EKC265. An ancillary effect of wet etching copper metallization rather than removing by means of mechanical polishing is that only the thin layer of underlying barrier metal layer has to be removed by means of mechanical polishing. As the barrier metal is a metal-silicon nitride compound, the polishing rate to remove it is close to that of the surrounding oxide. Therefore, less total polishing time is required to remove the copper metallization layer when EKC is used.