Reduced electromigration of Cu wires by surface coating

Electromigration in on-chip Cu interconnections with a selective electroless metal coating, CoWP, CoSnP, or Pd, on the top surface of Cu damascene lines has been investigated. The 10-20 nm thick metal cap significantly improves electromigration lifetime by providing protection against interface diffusion of Cu which has been the leading contributor to metal line failure by electromigration. © 2002 American Institute of Physics.