Dry-etch for selective tungsten removal
US9412608B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 2015 |
| Grant date | Aug 9, 2016 |
| Priority date | — |
| Expiry date | Feb 9, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32136
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods of selectively etching tungsten relative to silicon-containing films (e.g. silicon oxide, silicon carbon nitride and (poly)silicon) as well as tungsten oxide are described. The methods include a remote plasma etch formed from a fluorine-containing precursor and/or hydrogen (H2). Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the tungsten. The plasma effluents react with exposed surfaces and selectively remove tungsten while very slowly removing other exposed materials. Sequential and simultaneous methods are included to remove thin tungsten oxide which may, for example, result from exposure to the atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.