Tungsten oxide processing
US8951429B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2013 |
| Grant date | Feb 10, 2015 |
| Priority date | — |
| Expiry date | Dec 20, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31122
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Methods of selectively etching tungsten oxide relative to tungsten, silicon oxide, silicon nitride and/or titanium nitride are described. The methods include a remote plasma etch using plasma effluents formed from a fluorine-containing precursor in combination with ammonia (NH3). Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the tungsten oxide. The plasmas effluents react with exposed surfaces and selectively remove tungsten oxide while very slowly removing other exposed materials. Increasing a flow of ammonia during the process removes a typical skin of tungsten oxide having higher oxidation coordination number first and then selectively etching lower oxidation tungsten oxide. In some embodiments, the tungsten oxide etch selectivity results partly from the presence of an ion suppression element positioned between the remote plasma and the substrate processing region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.