Anode having separately excitable sections to compensate for non-uniform plating deposition across the surface of a wafer due to seed layer resistance

Abstract

A plating apparatus, anode assembly, and method therefor are disclosed herein that improves the uniformity of the plating deposition across the surface of a wafer, substrate or article. This improvement is accomplished by compensating for the uneven plating deposition caused by a seed layer disposed on the article. The seed layer typically has a high resistance. As a result of the high resistance characteristic of the seed layer, plating currents that flow through substantial portion of the seed layer to the cathode contact encounter more resistance than plating currents that flow through less seed layer. This produces non-uniformity in the plating currents across the surface of the wafer, which results in an uneven plating deposition across the surface of the wafer. The plating apparatus, anode, and method therefor provide an anode having a plurality of separate anode sections designed to plate different surface regions of the wafer. The anode sections are applied with respective anode voltages selected or configured to provide a more uniform plating current distribution across the surface of the wafer. As a result, a more uniform plating deposition across the surface of the wafer may be achieved by proper design of the anode sections and the voltages exciting respective anode sections.