Anisotropic etch process for tungsten metallurgy
US4786360A · kind A · utility
224Cited by
5References
9Claims
0Family size
Assignee
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Key dates
| Filing date | Mar 30, 1987 |
| Grant date | Nov 22, 1988 |
| Priority date | — |
| Expiry date | Mar 30, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32136
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for anisotropically etching a thick tungsten layer atop a thin underlayer comprised of titanium nitride, by exposure to a gaseous plasma comprised of a binary mixture of chlorine gas and oxygen, wherein oxygen comprises approximately 25%-45% of the mixture by volume. This plasma provides a combination of high tungsten etch rate, highly uniform etching, anisotropic profiles, and high etch rate ratio to underlaying glass passivation layers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.