Patent attributes
A copper electroplating bath composition and a method of copper electroplating to improve gapfill are provided. The method of electroplating includes providing an aqueous electroplating composition, comprising copper, at least one acid, at least one halogen ion, an additive including an accelerating agent, a suppressing agent, and a suppressing-accelerating agent, and the solution and mixture products thereof; contacting a substrate with the plating composition; and impressing a multi-step waveform potential upon the substrate, wherein the multi-step waveform potential includes an entry step, wherein the entry step includes a first sub-step applying a first current and a second sub-step applying second current, the second current being greater than the first current. The accelerating agent is provided in concentration of greater than 1.5 ml/liter, the suppressing agent is provided in concentration of greater than 15 ml/liter, and the accelerating-suppressing agent is provided in concentration of greater than 10 ml/liter.