Electroplating anode including membrane partition system and method of preventing passivation of same

• US 6,126,798 A
• Filed: 11/13/1997
• Issued: 10/03/2000
• Est. Priority Date: 11/13/1997
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation, Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: International Business Machines Corporation, Novellus Systems Incorporated (Lam Research Corporation)
• Inventors: Dukovic, John Owen, Contolini, Robert J., Reid, Jonathan David
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/969,196
• Time in Patent Office: 1,055 Days
• Field of Search: 204/282, 204/283, 204/297 R, 204/297 W, 118/232
• US Class Current: 205/143
• CPC Class Codes: C25D 17/00 Constructional parts, or assemblies thereof, of cells for electrolytic coating
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 17/008 Current shielding devices
• CPC Class Codes: C25D 17/10 Electrodes , e.g. composition, counter electrode

Abstract

An anode includes an anode cup, a membrane and ion source material, the anode cup and membrane forming an enclosure in which the ion source material is located. The anode cup includes a base section having a central aperture and the membrane also has a central aperture. A jet is passed through the central apertures of the base section of the anode cup and through the membrane allowing plating solution to be directed at the center of a wafer being electroplated.

Claims

1. An anode comprising:

an anode cup;

a membrane; and

an ion source material, said anode cup and membrane forming an enclosure in which said ion source material is located.

2. The anode of claim 1 wherein said anode cup comprises a disk shaped base section having a first central aperture and said membrane has a second central aperture, wherein a jet passes through said first central aperture and said second central aperture.

3. The anode of claim 2 wherein said jet comprises an inlet, said inlet being located between said membrane and said base section of said anode cup.

4. The anode of claim 3 further comprising a checkvalve at said inlet.

5. The anode of claim 2 further comprising a first seal ring attached to said membrane at said second central aperture, said first seal ring forming a seal with said jet.

6. The anode of claim 1 wherein said membrane is disk shaped.

7. The anode of claim 1 wherein said membrane is shaped as a frustum of an inverted right circular cone having a base section at said anode cup.

8. The anode of claim 1 wherein said anode cup comprises a cylindrical wall section and a disk shaped base section, a first end of said wall section being attached to said base section, a second end of said wall section having one or more outlets.

9. The anode of claim 8 further comprising a second seal ring attached to an outer circumference of said membrane, said second seal ring forming a seal with said second end of said wall section.

10. The anode of claim 1 further comprising an electrical contact electrically connected with said ion source material.

11. The anode of claim 10 wherein said electrical contact is a mesh of electrically conductive material.

12. The anode of claim 11 wherein said electrical contact comprises titanium mesh.

13. The anode of claim 10 wherein said electrical contact comprises a plate with raised perforations.

14. The anode of claim 10 further comprising a rod passing through said anode cup, said rod being electrically connected to said electrical contact.

15. The anode of claim 1 wherein said ion source material comprises copper.

16. The anode of claim 1 wherein said ion source material comprises a plurality of granules.

17. The anode of claim 1 wherein said ion source material comprises a single integral piece.

18. The anode of claim 1 wherein said anode cup comprises an inlet on a base section of said anode cup.

19. The anode of claim 1 wherein said anode cup comprises an inlet on a wall section of said anode cup.

20. The anode of claim 1 wherein said anode cup comprises a base section having a plurality of perforations extending from a first surface to an second surface of said base section.

21. The anode of claim 20 further comprising a filter sheet on said second surface of said base section.

22. The anode of claim 21 further comprising an electrical contact on said filter sheet, said ion source material being electrically connected to said contact.

23. The anode of claim 1 wherein said anode cup comprises a polymer.

24. The anode of claim 23 wherein said polymer is selected from the group consisting of polypropylene and polyethylene.

25. The anode of claim 1 wherein said membrane has a porosity, said porosity being sufficient to prevent particulates larger than a predetermined size from passing through said membrane.

26. The anode of claim 25 wherein said porosity is sufficient to prevent particulates larger than 0.1 micron from passing through said membrane.

27. A method of preventing anode passivation comprising the steps of:

providing an anode comprising an anode cup, a membrane and ion source material, said ion source material being located in an enclosure formed by said anode cup and said membrane; and

introducing plating solution into said enclosure and across said ion source material, wherein at least a first portion of said plating solution introduced into said enclosure exits said enclosure through said membrane.

28. The method of claim 27 wherein said membrane has a porosity, said porosity being sufficient to prevent particulates larger than a predetermined size from passing through said membrane.

29. The method of claim 27 wherein said anode cup comprises at least one plating solution outlet, wherein at least a second portion of said plating solution introduced into said enclosure exits said enclosure through said plating solution outlet.

30. The method of claim 29 further comprising the step of removing gas bubbles from said enclosure through said at least one plating solution outlet.

31. An electroplating system comprising:

a bath containing an electroplating solution;

a power supply;

a substrate immersed in said electroplating solution, a negative terminal of said power supply being electrically connected to said substrate; and

an anode, a positive terminal of said power supply being electrically connected to said anode, said anode comprising;

an anode cup;

a membrane; and

an ion source material, said anode cup and membrane forming an enclosure in which said ion source material is located.

32. The electroplating system of claim 31 wherein said anode comprises at least one inlet for allowing a flow of said electroplating solution into said anode.

33. The electroplating system of claim 32 wherein said anode comprises at least one outlet for allowing a flow of said electroplating solution out of said anode.

34. The electroplating system of claim 33 comprising a jet extending through said anode for directing a flow of said electroplating solution towards said substrate.

35. The electroplating system of claim 34 wherein at least one of said at least one inlets is in flow communication with said jet.

36. The electroplating system of claim 35 wherein at least one of said at least one outlets is in flow communication with an overflow reservoir.

37. The electroplating system of claim 36 comprising a flow path between said overflow reservoir and said jet.

38. The electroplating system of claim 34 wherein at least one of said at least one outlets is in flow communication with said jet.