Random local metal cap layer formation for improved integrated circuit reliability
AssigneeInternational Business Machines Corporation
InventorsRonald G. Filippi, Erdem Kaltalioglu, Wai-Kin Li, Ping-Chuan Wang, Lijuan Zhang
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Abstract
A method and structure for preventing integrated circuit failure due to electromigration and time dependent dielectric breakdown is disclosed. A randomly patterned metal cap layer is selectively formed on the metal interconnect lines (typically copper (Cu)) with an interspace distance between metal cap segments that is less than the critical length (for short-length effects). Since the diffusivity is lower for the Cu/metal cap interface than for the Cu/dielectric cap interface, the region with a metal cap serves as a diffusion barrier.
Claims9
1-12. (canceled)
A semiconductor structure comprising:
- a semiconductor substrate;
- a metal interconnect region formed on the semiconductor substrate;
- a plurality of randomly placed metal cap regions disposed on the metal interconnect region;
- and
- a dielectric capping layer disposed on the interconnect region and the plurality of randomly placed metal cap regions.
Dependencies are inferred from the claim text.