Method of forming a Cu interconnect, device structure, and Cu interconnect

摘要

The present invention provides a technique for improving the reliability in a Cu interconnect using a Cu intermetallic compound. In one aspect, a method of forming a Cu interconnect in a dielectric over a Cu line comprises: forming at least one via in the dielectric over a Cu line; Depositing a metal layer on the dielectric and lining the vias so as to contact the Cu line at at least one metal capable of reacting with Cu to form a Cu intermetallic compound And annealing the metal layer and the Cu line under conditions sufficient to form a Cu intermetallic barrier at the bottom of the via, and Cu in the via to form a Cu interconnect. Plating the Cu interconnects separated from the Cu lines by a Cu intermetallic barrier. Also, a device structure is provided. [Selected figure] Figure 1