Apparatus for processing surface of workpiece with small electrodes and surface contacts
View Patent ↗Deposition of conductive material on or removal of conductive material from a workpiece frontal side of a semiconductor workpiece is performed by providing an anode having an anode area which is to face the workpiece frontal side, and electrically connecting the workpiece frontal side with at least one electrical contact, outside of the anode area, by pushing the electrical contact and the workpiece frontal side into proximity with each other. A potential is applied between the anode and the electrical contact, and the workpiece is moved with respect to the anode and the electrical contact. Full-face electroplating or electropolishing over the workpiece frontal side surface, in its entirety, is thus permitted.
1. An apparatus for processing a surface of a workpiece using a solution, comprising:
an electrode assembly comprising at least one electrical contact and an electrode having an electrode surface configured to face the front surface of the workpiece, the at least one electrical contact being in fixed relation to the electrode within the electrode assembly, wherein the at least one electrical contact is configured to connect power to the surface of the workpiece, wherein the at least one electrical contact substantially surrounds a periphery of the electrode surface;
a power supply connected to the at least one electrical contact and the electrode, the power supply configured to apply different polarities to the at least one electrical contact and the electrode to apply a potential difference between the front surface of the workpiece and the electrode; and
a moving mechanism configured to move at least one of the electrode assembly and the workpiece to establish relative motion between the electrode and the workpiece during processing.
2. The apparatus of claim 1 , wherein the at least one electrical contact is located on a periphery of the electrode assembly.
3. The apparatus of claim 2 , wherein the at least one electrical contact includes a plurality of electrical contacts surrounding the electrode surface.
4. The apparatus of claim 3 , wherein the electrode surface is smaller than the front surface of the workpiece.
5. The apparatus of claim 1 , further comprising a pad placed on the electrode surface configured to polish the front surface of the workpiece.
6. The apparatus of claim 5 , wherein the pad has a polishing surface that is smaller than the front surface of the workpiece.
7. The apparatus of claim 5 , the wherein the electrode assembly is configured to flow the solution through the pad towards the front surface of the workpiece.
8. The apparatus of claim 1 , further comprising a workpiece holder configured to hold the workpiece.
9. The apparatus of claim 8 , wherein the workpiece holder is configured to seal an edge of the workpiece while exposing the front surface of the workpiece.
10. The apparatus of claim 8 , wherein the workpiece holder is configured to seal a back of the workpiece while exposing the front surface of the workpiece.
11. The apparatus of claim 1 , wherein the at least one electrical contact includes a plurality of electrical contacts surrounding the electrode surface.
12. The apparatus of claim 11 , wherein the electrical contacts are placed on a contact ring that is fixed on a periphery of the electrode assembly.
13. The apparatus of claim 1 , wherein the at least one electrical contact is made of at least one of conductive brushes, pins, balls, rollers and wires.
14. The apparatus of claim 1 , wherein the electrode assembly is configured to flow the solution through the electrode towards the front surface of the workpiece.
15. The apparatus of claim 1 , wherein the moving mechanism is configured to move the electrode assembly laterally with respect to the front surface of the workpiece.
16. The apparatus of claim 1 , wherein the moving mechanism is configured to rotate the workpiece with respect to the electrode assembly.
17. The apparatus of claim 1 , wherein the moving mechanism is configured to move the workpiece laterally with respect to the electrode assembly.
18. The apparatus of claim 1 , wherein the moving mechanism is configured to rotate the electrode assembly with respect to the front surface of the workpiece.
19. The apparatus of claim 1 , wherein the moving mechanism is configured to rotate the workpiece with respect to the electrode assembly and to move the workpiece laterally with respect to the electrode assembly.
20. The apparatus of claim 1 , wherein the at least one electrical contact is configured to sweep the surface of the workpiece and to slide off the front surface of the workpiece during processing.