Process for copper etch back
US5968847A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1998 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Mar 13, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/7684
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In the preparation of semiconductor structures having multilevel copper conductive features which must be interconnected, it is frequently desired to remove portions of a copper layer deposited over a substrate. In particular, where lines and contacts are created by depositing a copper layer to fill trenches and vias present in a dielectric layer, it is desired to remove the portion of the copper layer which does not form the desired line or contact. The present invention provides a method of etching a copper layer (film) to remove the portion of the film which is not part of the desired conductive interconnect structure, while avoiding over etching of the structure and the formation of corrosive surface contaminants on the surface of the etched copper. The method of etching is referred to as the etchback process, since, in a typical fabrication process, the deposited copper layer is etched back to the upper or "field" surface of a substrate containing trenches and vias which are filled by the copper. The copper layer etchback may be conducted on a substrate surface using a low temperature regime, below about 150.degree. C. Within this low temperature regime, the etchback is prefer…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.