Method and apparatus for electroplating including remotely positioned second cathode
US7854828B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 2006 |
| Grant date | Dec 21, 2010 |
| Priority date | — |
| Expiry date | Sep 30, 2029 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D17/002
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An apparatus for electroplating a layer of metal on the surface of a wafer includes a second cathode located remotely with respect to the wafer. The remotely positioned second cathode allows modulation of current density at the wafer surface during an entire electroplating process. The second cathode diverts a portion of current flow from the near-edge region of the wafer and improves the uniformity of plated layers. The remote position of second cathode allows the insulating shields disposed in the plating bath to shape the current profile experienced by the wafer, and therefore act as a “virtual second cathode”. The second cathode may be positioned outside of the plating vessel and separated from it by a membrane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.