Cathode current control system for a wafer electroplating apparatus
US6004440A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1997 |
| Grant date | Dec 21, 1999 |
| Priority date | — |
| Expiry date | Sep 18, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S204/07
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A cathode current control system employing a current thief for use in electroplating a wafer is set forth. The current thief comprises a plurality of conductive segments disposed to substantially surround a peripheral region of the wafer. A first plurality of resistance devices are used, each associated with a respective one of the plurality of conductive segments. The resistance devices are used to regulate current through the respective conductive finger during electroplating of the wafer. Various constructions are used for the current thief and further conductive elements, such as fingers, may also be employed in the system. As with the conductive segments, current through the fingers may also be individually controlled. In accordance with one embodiment of the overall system, selection of the resistance of each respective resistance devices is automatically controlled in accordance with predetermined programming.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.