Cleaning electroplating substrate holders using reverse current deplating

Patent metadata

Field	Value
Publication number	US-11542630-B2
Application number	US-201916715501-A
Country	US
Kind code	B2
Filing date	Dec 16, 2019
Priority date	Mar 30, 2012
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

Provided are cleaning methods and systems to remove unintended metallic deposits from electroplating apparatuses using reverse current deplating techniques. Such cleaning involves positioning a cleaning (deplating) disk in an electroplating cup similar to a regular processed substrate. The front surface of the cleaning disk includes a corrosion resistant conductive material to form electrical connections to deposits on the cup's surfaces. The disk is sealed in the cup and submerged into a plating solution. A reverse current is then applied to the front conductive surface of the disk to initiate deplating of the deposits. Sealing compression in the cup may change during cleaning to cause different deformation of the lip seal and to form new electrical connections to the deposits. The proposed cleaning may be applied to remove deposits formed during electroplating of alloys, in particular, tin-silver alloys widely used for semiconductor and wafer level packaging.

First claim

What is claimed is:

1. A deplating disk for cleaning a plating cell wafer holder assembly, the deplating disk comprising:
a perimeter region along a periphery of the deplating disk and comprising a corrosion-resistant conductive material positioned for making electrical contact with a plurality of electrical contacts in the plating cell wafer holder assembly; and
an interior region at a center portion of the deplating disk and comprising an insulating material, wherein the corrosion-resistant conductive material of the perimeter region forms a ring around the insulating material of the interior region, wherein the deplating disk is shaped as a circular wafer having a diameter of 300 mm or 450 mm.

2. The deplating disk of claim 1 , wherein the corrosion-resistant conductive material is a noble metal.

3. The deplating disk of claim 1 , wherein the corrosion-resistant conductive material is selected from the group consisting of: titanium, tantalum, vanadium, tungsten, niobium, chromium, and combinations thereof.

4. The deplating disk of claim 1 , wherein the insulating material is polyvinyl chloride (PVC).

5. The deplating disk of claim 1 , wherein the deplating disk comprises a deplating face and an opposite face, wherein the deplating face comprises a step extending away from the opposite face of the deplating disk, wherein the step is at least 1 mm long.

6. The deplating disk of claim 5 , wherein the step is positioned between 0.1-5 mm inward from a perimeter of the deplating disk.

7. The deplating disk of claim 1 , wherein the corrosion-resistant conductive material is formed on a deplating face of the deplating disk.

8. The deplating disk of claim 7 , wherein the insulating material is also formed on the deplating face of the deplating disk, wherein the deplating disk further comprises:
an insulated body on which the corrosion-resistant conductive material and the insulating material are formed, wherein the insulated body comprises silicon.

9. The deplating disk of claim 1 , wherein a width of the corrosion-resistant conductive material is between 1 mm and 10 mm.

10. The deplating disk of claim 1 , wherein the deplating disk is configured to remove metallic deposits from the plating cell wafer holder assembly when anodic current is applied to the corrosion-resistant conductive material of the deplating disk.

Assignees

• Novellus Systems Inc

Inventors

• Chua Lee Peng
• Mayer Steven T
• Ponnuswamy Thomas A
• Kumar Santosh

Classifications

• H10P72/7602

  the wafers being placed on a robot blade or gripped by a gripper for conveyance · CPC title

• H10P72/3404

  Storage means · CPC title

• H10P72/3402

  Mechanical parts of transfer devices · CPC title

• C25D17/06 Primary

  Suspending or supporting devices for articles to be coated · CPC title

• C25D17/001 Primary

  Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells · CPC title