Patent ID: 7351651
Filing Date: 2008-04-01
Classification: H01L

Abstract:
1. A wafer-level method of fabricating a metal structure for a contact pad of an integrated circuit having copper interconnecting metallization protected by an overcoat layer including silicon nitride, comprising the steps of: opening a window in said overcoat layer to expose said copper metallization, said window having walls reaching through the thickness of said overcoat layer; depositing a barrier metal layer over said wafer to cover said exposed copper metallization, window walls, and overcoat surface; depositing a bondable metal layer over said barrier layer in a thickness sufficient to fill said overcoat window; chemically-mechanically polishing said wafer so that said layers of bondable metal and barrier metal are removed over said overcoat outside said window; and chemically-mechanically polishing said wafer to remove the bondable metal and barrier metal to form a structural step of pre-determined height between the overcoat surface and the polished surface of the bondable metal.