Chemically preventing Cu dendrite formation and growth by immersion

摘要

The formation and/or growth of dendrites emanating from Cu or Cu alloy lines into a bordering open dielectric field are prevented or substantially reduced by chemically removing a portion of the surface from the dielectric field and from between the lines after CMP by immersing the wafer in a bath containing a chemical agent. Embodiments include removing up to 60 Å of silicon oxide by immersing the wafer in an acidic solution, such as a solution of hydrofluoric acid and water.