Role of Cu−Benzotriazole Nanoparticles in Passivation Film Formation

The present study deals with the formation and characterization of Cu−benzotriazole (BTA) nanoparticles, which are relevant to copper surface corrosion and passivation. More specifically, we demonstrated that under oxidizing conditions, the cupric ions diffused out of the copper substrate surface can induce the formation of Cu−BTA nanoparticles. These nanoparticles can subsequently precipitate back to the copper surface or form a cross-link with the copper species on the original surface. Such a precipitation path for the formation of a copper-passivating film may supplement or compete with the direct growth mechanism in which the passivating agent interacts with copper species directly before they diffuse out of the substrate surface.