Electroplating contact ring with radially offset contact fingers

• US 10,113,245 B2
• Filed: 03/02/2017
• Issued: 10/30/2018
• Est. Priority Date: 03/24/2016
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Wilson, Gregory J.
• Primary Examiner(s): Wittenberg, Stefanie S
• Application Number:
  US15/447,458
• Publication Number:
  US 20170275776A1
• Time in Patent Office: 607 Days
• Field of Search: 118500
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 17/005 Contacting devices
• CPC Class Codes: C25D 5/022 using masking means
• CPC Class Codes: C25D 5/56 of plastics
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H01R 39/18 Contacts for co-operation with commutator or slip-ring, e.g. contact brush
• CPC Class Codes: H01R 39/64 Devices for uninterrupted current collection
• CPC Class Codes: H01R 4/48 utilising a spring, clip, or other resilient member H01R4/52 takes precedence

Abstract

A contact ring for an electroprocessor has redundant contact fingers, i.e., more contact fingers than needed for contacting a very narrow edge exclusion zone on a substrate such as a semiconductor wafer. The contact fingers have slightly different lengths so that they extend to different radial positions. By providing redundant contact fingers, and by slightly varying the lengths of the contact fingers, a sufficient number of contact fingers make contact with the electrically conductive surface in the edge exclusion zone to provide good electroplating results.

Claims

1. An electroprocessing apparatus comprising:

a head;

a rotor in the head;

an annular contact ring attachable onto the rotor;

a frame including a vessel, with the head movable to position the annular contact ring in the vessel and out of the vessel;

a plurality of first contact fingers aligned on the annular contact ring, with each of the first contact fingers having a first length;

a plurality of second contact fingers aligned on the annular contact ring, with each of the second contact fingers having a second length less than the first length;

wherein each of the plurality of first and second contact fingers are aligned on a radius of the annular contact ring and extend radially inwardly from the annular contact ring; and

wherein the plurality of first and second contact fingers are arranged in a plurality of clusters disposed substantially around an entire diameter of the annular contact ring, with each cluster including one first contact finger and one second contact finger.

2. The apparatus of claim 1 wherein substantially every contact finger is flat and rectangular.

3. The apparatus of claim 2 wherein the plurality of first and second contact fingers are equally spaced apart.

4. The apparatus of claim 3 wherein the first length is 0.05 to 0.2 mm greater than the second length.

5. The apparatus of claim 4 with the annular contact ring having a total of 300 to 1000 contact fingers.

6. The apparatus of claim 5 further comprising an annular seal overlying the plurality of first and second contact fingers.