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 with a solution comprising HF and H2O. Embodiments include removing up to 50 Å of silicon oxide by treating the wafer in a spray acid processor with a solution containing HF and deionized water at a water to acid ratio of about 100:1 to about 250:1.