Anti-corrosion treatment for patterning of metallic layers

摘要

An improved method is provided for defining interconnect patterns in an integrated circuit fabricated on a semiconductor wafer. The improvement comprises the step of immersing the wafer in a weak base solution, prior to etching a titanium-tungsten barrier layer, so as to remove from the wafer chlorides and flourides remaining as a result of a previous step of etching a conductor layer. In a preferred embodiment of the invention, a step of immersing the wafer in a strong acid solution is also performed to remove chlorides from the wafer.