Patent ID: 6693365
Filing Date: 2004-02-17
Classification: C25F,H01L

Abstract:
A system comprising:a tank holding an electrolytic solution; a primary cathode submersed within the electrolytic solution in the tank, the primary cathode at least partially insulated from the electrolytic solution; a semiconductor wafer submersed within electrolytic solution in the tank, the semiconductor wafer acting as an anode and having one or more alignment mark regions, the semiconductor wafer having been electrochemically plated with a metal; one or more extension cathodes submersed within the electrolytic solution in the tank, each extension cathode at least partially insulated from the electrolytic solution except for a part of a first end and a second end thereof, the part of the first end closely positioned over a corresponding alignment mark region of the semiconductor wafer, the second end situated on a corresponding exposed part of the primary cathode; and, a power source having a negative terminal operatively coupled to the primary cathode and a positive terminal operatively coupled to the semiconductor wafer, such that current from the power source electrochemically deplates the metal substantially from the one or more alignment mark regions of the semiconductor wafer, substantially exposing one or more alignment marks within the one or more alignment mark regions.