Highly selective silicon oxide/silicon nitride etching by selective boron nitride or aluminum nitride deposition
US11152217B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 2020 |
| Grant date | Oct 19, 2021 |
| Priority date | — |
| Expiry date | Jun 16, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for selective etching of silicon oxide relative to silicon nitride includes exposing a substrate to a first gas that forms a first layer on the silicon oxide film and a second layer on the silicon nitride film, where the first gas contains boron, aluminum, or both boron and aluminum, exposing the substrate to a nitrogen-containing gas that reacts with the first layer to form a first nitride layer on the silicon oxide film and reacts with the second layer to form a second nitride layer on the silicon nitride film, where a thickness of the second nitride layer is greater than a thickness of the first nitride layer. The method further includes exposing the substrate to an etching gas that etches the first nitride layer and silicon oxide film, where the second nitride layer protects the silicon nitride film from etching by the etching gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.