STRUCTURE AND METHOD FOR CONTACT PADS HAVING AN OVERCOAT-PROTECTED BONDABLE METAL PLUG OVER COPPER-METALLIZED INTEGRATED CIRCUITS

摘要

A metal structure for a contact pad of an integrated circuit (IC), which has copper interconnecting metallization (311). A portion (301) of this metallization is exposed to provide a contact pad to the IC. A conductive barrier layer (330) is positioned on the exposed portion of the copper metallization. A plug (350) of bondable metal, preferably aluminum between about 0.4 and 1.4 µm thick, is positioned on the barrier layer. A protective overcoat layer (320) surrounds the plug and has a thickness (320b) so that the exposed surface (322) of the plug lies at or below the exposed surface (320a) of the overcoat layer. Optionally, a portion (321) of the overcoat layer between about 0.1 and 0.3µm wide may overlap the perimeter of the plug.