Discontinuous/non-uniform metal cap structure and process for interconnect integration

Abstract

An interconnect structure including a noble metal-containing cap that is present at least on some portion of an upper surface of at least one conductive material that is embedded within an interconnect dielectric material is provided. In one embodiment, the noble metal-containing cap is discontinuous, e.g., exists as nuclei or islands on the upper surface of the at least one conductive material. In another embodiment, the noble metal-containing cap has a non-uniform thickness across the surface of the at least one conductive material.

Description

technical field [0001] The present invention relates to semiconductor interconnect structures and methods of manufacturing the same. More particularly, the present invention relates to semiconductor interconnect structures having improved resistance to electromigration (EM) without degrading time-dependent dielectric breakdown reliability. Background technique [0002] In general, a semiconductor device includes a plurality of circuits formed on an integrated circuit (IC) fabricated on a semiconductor substrate. Complex signal path networks are typically routed to connect circuit elements distributed across the surface of the substrate. Efficient routing of these signals on the device requires the formation of multilevel or multilayer schemes, such as single damascene or dual damascene wiring structures. The wiring structures typically include copper (Cu) because Cu-based interconnects carry signals at a higher speed than aluminum (Al)-based interconnects between the large...

AI Technical Summary

Problems solved by technology

While this prior art recessed process provides a metal cap only on the surface of the recessed conductive material, such a process is problematic due to the high associated process costs

[0010] It is also worth mentioning that metal caps may corrode during cleaning in dilute hydrofluoric acid (typically used to clean the surface of interconnect dielectric materials)

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