Ammonium fluoride pre-clean protection
US11232947B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 2020 |
| Grant date | Jan 25, 2022 |
| Priority date | — |
| Expiry date | Sep 1, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76843
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An ammonium fluoride gas may be used to form a protection layer for one or more interlayer dielectric layers, one or more insulating caps, and/or one or more source/drain regions of a semiconductor device during a pre-clean etch process. The protection layer can be formed through an oversupply of nitrogen trifluoride during the pre-clean etch process. The oversupply of nitrogen trifluoride causes an increased formation of ammonium fluoride, which coats the interlayer dielectric layer(s), the insulating cap(s), and/or the source/drain region(s) with a thick protection layer. The protection layer protects the interlayer dielectric layer(s), the insulating cap(s), and/or the source/drain region(s) during the pre-clean process from being etched by fluorine ions formed during the pre-clean process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.