Method to avoid copper contamination of a via or dual damascene structure

摘要

A process for preventing interconnect metal diffusion into the surrounding dielectric material. Prior to the formation of a metal interconnect in an opening of a dielectric region, the underlying metal surface is cleaned, during which metal can be deposited on the sidewalls of the opening. This metal can diffuse into the dielectric and cause leakage currents. To prevent deposition of the metal onto the sidewalls a barrier layer is deposited into the opening and sputtered onto the sidewalls before the metal surface cleaning step.