Abstract: Features such as bumps, pillars and/or vias can be plated best using current with either a square wave or square wave with open circuit wave form. Using the square wave or square wave with open circuit wave forms of plating current, produces features such as bumps, pillars, and vias with optimum shape and filling characteristics. Specifically, vias are filled uniformly and completely, and pillars are formed without rounded tops, bullet shape, or waist curves. In the process, the metalizing substrate is contacted with an electrolytic copper deposition composition. The deposition composition comprises a source of copper ions, an acid component selected from among an inorganic acid, an organic sulfonic acid, and mixtures thereof, an accelerator, a suppressor, a leveler, and chloride ions.