Etching of tungsten selective to titanium nitride
US7972966B2 · kind B2 · utility
1Cited by
2References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 19, 2009 |
| Grant date | Jul 5, 2011 |
| Priority date | — |
| Expiry date | Jul 28, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N70/8828
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention in one embodiment provides an etch method that includes providing a structure including a tungsten (W) portion and a titanium nitride (TiN) portion; applying a first etch feed gas of sulfur hexafluoride (SF6) and oxygen (O2), in which the ratio of sulfur hexafluoride (SF6) to oxygen (O2) ranges from 1:3.5 to 1:4.5; and applying a second etch feed gas of nitrogen trifluoride (NF3), helium (He) and chlorine (Cl2), in which the ratio of nitrogen trifluoride (NF3) to chlorine (Cl2) ranges from 1:5 to 2:5 and the ratio of helium (He) to nitrogen trifluoride (NF3) and chlorine (Cl2) ranges from 1:3 to 1:1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.