An electrochemical etching apparatus and method increasing the rate at which material is removed from a substrate such as a metallic surface. The apparatus includes an electrolyte delivery system positioned below and centered beneath the center of the substrate (e.g., a wafer) to be etched so that the center axis of the delivery system corresponds to the center of the wafer. The electrolyte delivery system and the wafer are then rotated relative to each other as the electrolyte is discharged from the delivery system and toward the surface of the wafer. A corresponding method for electrochemically etching a surface of the wafer with an electrolyte is also provided.
Dr. Madhav Datta, Edelstein, D. Charles, and Uzoh, C. Emeka, “Apparatus and method for the electrochemical etching of a wafer”, U.S. Patent US 08/968,1902000.