Method of utilizing hard mask for copper plasma etch
US6797640B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 2001 |
| Grant date | Sep 28, 2004 |
| Priority date | — |
| Expiry date | Nov 6, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A hard mask, e.g., a silicon dioxide or silicon nitride film, is used to avoid organic polymer materials in copper plasma etch applications. The hard mask would be deposited as a blanket layer on the Cu metal layer and itself be patterned and etched with a conventional photolithographic resist pattern. The hard mask etch is stopped shortly before the Cu surface is exposed. Halting the hard mask etch before the Cu surface is exposed facilitates the use of conventional cleaning processes following the hard mask etch. The remaining thin layer of hard mask can be etched through during the beginning of the Cu metal etch process. Any remaining hard mask deposited on the Cu metal layer can form a part of a new dielectric layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.