Abstract: A megasonic plating technique employs a megasonic transducer to create a ridge of electrolyte that extends upward above a plating tray. A chuck holds the substrate to be plated so the face of the wafer is oriented downwards. The megasonic transducer extends along a base of the center part of the tray, and an elongated anode element is positioned above the transducer. Spargers introduce electrolyte into the tray non-turbulently along opposite sides of the transducer. There is a transverse relative motion created between the tray and the chuck so that the ridge of electrolyte sweeps across the face of the substrate.