A process used to prevent attack of an aluminum based structure, exposed in a non-fully landed via hole, from solvents used during the wet stripping cycle, performed to remove the via hole defining photoresist shape, has been developed. The process features the formation of a protective aluminum oxide layer, on the exposed side of the aluminum based structure, via use of a plasma treatment, performed in an H.sub.2 O/N.sub.2 ambient. The H.sub.2 O/N.sub.2 plasma treatment procedure is performed after a dry plasma, photoresist stripping step, but prior to a final wet photoresist stripping step. The aluminum oxide layer offers protection of the exposed regions of the aluminum structure, located in the non-fully landed via hole, from reaction or corrosion, that can result from exposure of aluminum to the solvents used in the final wet photoresist stripping cycle.