Tungsten chemical mechanical polishing for reduced oxide erosion
US11643599B2 · kind B2 · utility
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2References
16Claims
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Key dates
| Filing date | Jul 12, 2019 |
| Grant date | May 9, 2023 |
| Priority date | — |
| Expiry date | Jul 12, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/7684
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
This invention pertains to slurries, methods and systems that can be used in chemical mechanical planarization (CMP) of tungsten containing semiconductor device. Using the CMP slurries with additives to counter lowering of pH by tungsten polishing byproducts and maintain pH 4 or higher, the erosion of dense metal (such as tungsten) structures can be greatly diminished.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.