Method and apparatus for uniform electropolishing of damascene ic structures by selective agitation
US6709565B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2001 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Sep 28, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32134
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention pertains to apparatus and methods for planarization of metal surfaces having both recessed and raised features, over a large range of feature sizes. The invention accomplishes this by increasing the fluid agitation in raised regions with respect to recessed regions. That is, the agitation of the electropolishing bath fluid is agitated or exchanged as a function of elevation on the metal film profile. The higher the elevation, the greater the movement or exchange rate of bath fluid. In preferred methods of the invention, this agitation is achieved through the use of a microporous electropolishing pad that moves over (either near or in contact with) the surface of the wafer during the electropolishing process. Thus, methods of the invention are electropolishing methods, which in some cases include mechanical polishing elements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.