Method of fabricating improved copper metallization including forming and removing passivation layer before forming capping film

摘要

A selected passivating layer is purposely formed on an exposed surface of a Cu and/or Cu alloy interconnect member, thereby avoiding the adverse consequences stemming from formation of a thick copper oxide layer thereon. The passivating layer is formed by treating the exposed surface of the Cu or Cu alloy interconnect member: (a) with a copper corrosion-inhibiting chemical; or (b) by electroless plating a metal layer on the surface of the Cu or Cu alloy layer; or (c) depositing a metallic compound on the surface of the Cu or Cu alloy layer by CVD. The passivating layer can then be removed. Embodiments include electroplating or electroless plating Cu or a Cu alloy to fill a damascene opening in an ILD, chemical mechanical polishing, then treating the exposed surface of the Cu/Cu alloy interconnect to form the passivating, layer thereon, and depositing a silicon nitride diffusion barrier layer thereon.