Method to create air gaps
US11088019B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 2018 |
| Grant date | Aug 10, 2021 |
| Priority date | — |
| Expiry date | Feb 9, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D30/6219
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Tin oxide films are used to create air gaps during semiconductor substrate processing. Tin oxide films, disposed between exposed layers of other materials, such as SiO2 and SiN can be selectively etched using a plasma formed in an H2-containing process gas. The etching creates a recessed feature in place of the tin oxide between the surrounding materials. A third material, such as SiO2 is deposited over the resulting recessed feature without fully filling the recessed feature, forming an air gap. A method for selectively etching tin oxide in a presence of SiO2, SiC, SiN, SiOC, SiNO, SiCNO, or SiCN, includes, in some embodiments, contacting the substrate with a plasma formed in a process gas comprising at least about 50% H2. Etching of tin oxide can be performed without using an external bias at the substrate and is preferably performed at a temperature of less than about 100° C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.