Etching composition effective to selectively wet etch a silicon nitride film
US10995268B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2019 |
| Grant date | May 4, 2021 |
| Priority date | — |
| Expiry date | Aug 27, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K13/04
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A silicon nitride etching composition effective to selectively etch a silicon nitride film contains an inorganic acid; a silicon-based compound; from 0.01 to 1 wt%, based on total weight of the etching composition, of an ammonium-based compound composed of ammonium acetic acid; and water. The silicon-based compound may be represented by Chemical Formula 1 below or Chemical Formula 2 below, (R1)3-Si-R2-Si-(R1)3 Chemical Formula 1,(R3)3-Si-R4-Si-(R3)3 Chemicl Formula 2.A method of etching a silicon nitride film includes providing the etching composition; and wet etching the silicon nitride film in the etching composition at an etching rate that is at least 200 times faster than a corresponding silicon oxide film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.