Additive to phosphoric acid etchant
US10913893B2 · kind B2 · utility
0Cited by
2References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 5, 2018 |
| Grant date | Feb 9, 2021 |
| Priority date | — |
| Expiry date | Dec 5, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B43/27
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Embodiments of compositions of a wet etchant and additive thereto for selectively etching silicon nitride to silicon oxide are disclosed. In an example, a composition of an additive to a phosphoric acid etchant includes an inhibitor and a dispersant. The inhibitor is absorbable on a surface of silicon oxide and capable of inhibiting etching of the surface of silicon oxide by the phosphoric acid etchant. The dispersant is capable of reacting with a by-product of a reaction between the phosphoric acid etchant and at least one of silicon oxide and silicon nitride and reducing a viscosity of the phosphoric acid etchant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.