US Patent 7291558 Copper interconnect wiring and method of forming thereof

Capping layer or layers on a surface of a copper interconnect wiring layer for use in interconnect structures for integrated circuits and methods of forming improved integration interconnection structures for integrated circuits by the application of gas-cluster ion-beam processing. Reduced copper diffusion and improved electromigration lifetime result and the use of selective metal capping techniques and their attendant yield problems are avoided.