a method for making a semiconductor device includes cleaning a semiconductor wafer after a chemical mechanical polishing process to remove or reduce particles of copper , a corrosion inhibitor such as triazole , and a copper oxide layer on the copper layer . in order to prepare for plating the copper layer with a layer that functions as a barrier to copper migration or diffusion , the surface of the copper layer and the dielectric layer are treated with an oxidant , a surfactant , and copper - chelating agent . the copper - chelating is preferably a mild acid such as an organic acid . the oxidant is particularly useful in removing the corrosion inhibitor . the barrier layer , preferably conductive , is then plated on the surface of the copper layer . subsequent interlayer dielectric layers and copper layers follow that can use the same process .