Random local metal cap layer formation for improved integrated circuit reliability

摘要

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.

主权项

1. A method of fabricating a semiconductor structure, comprising:
depositing a directed self-assembly (DSA) material onto a plurality of metal interconnect regions; treating the DSA material to put the DSA material into a self-assembled state; forming a plurality of metal cap regions on the semiconductor structure; removing the DSA material; and depositing a dielectric cap layer onto the semiconductor structure.