Polishing compositions and methods for selectively polishing silicon nitride over silicon oxide films
US9558959B2 · kind B2 · utility
8Cited by
9References
24Claims
0Family size
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Key dates
| Filing date | Sep 17, 2015 |
| Grant date | Jan 31, 2017 |
| Priority date | — |
| Expiry date | Sep 17, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31055
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Stable aqueous polishing compositions that can selectively polish silicon nitride (SiN) films and nearly stop (or polish at very low rates) on silicon oxide films are provided herein. The compositions comprise an anionic abrasive, a nitride removal rate enhancer containing a carboxyl or carboxylate group, water, and optionally, an anionic polymer. The synergistic combination of anionic (negatively charged) abrasives and the nitride removal rate enhancer provide beneficial charge interactions with the dielectric films during CMP, a high SiN rate and selectivity enhancement (over oxide), and stable colloidal dispersed slurries.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.