Compositions and methods for selectively etching silicon nitride films
US12012540B2 · kind B2 · utility
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14Claims
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Key dates
| Filing date | May 20, 2022 |
| Grant date | Jun 18, 2024 |
| Priority date | — |
| Expiry date | May 20, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32134
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The invention relates to compositions and methods for the selective wet etching of a surface of a microelectronic device that contains both silicon nitride (SiN) and polysilicon. An etching composition as described comprises phosphoric acid, certain polysilicon corrosion inhibitors, along with certain silanes. The combination of the two components was found to greatly improve the selectivity of the silicon nitride etching composition in the presence of polysilicon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.