Method for etching silicon oxynitride and dielectric antireflection coatings
US6537918B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2001 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Jul 31, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/022
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for plasma etching a semiconductor film stack. The film stack includes at least one layer comprising silicon oxynitride. The method includes etching the silicon oxynitride-comprising layer using an etchant gas mixture comprising chlorine and at least one compound containing fluorine and carbon. The atomic ratio of fluorine to chlorine in the etchant gas ranges between about 3:1 and about 0.01:1; preferably, between about 0.5:1 and about 0.01:1; most preferably, between about 0.25:1 and about 0.1:1. The etchant gas forms a fluorine-comprising polymer or species which deposits on exposed surfaces adjacent to the silicon oxynitride-comprising layer in an amount sufficient to reduce the etch rate of an adjacent material (such as a photoresist) while permitting the etching of the silicon oxynitride-comprising layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.