Protective layer for quartz crucibles used for silicon crystallization
US6479108B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2001 |
| Grant date | Nov 12, 2002 |
| Priority date | — |
| Expiry date | Aug 31, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B35/002
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A thermodynamically stable, protective coating layer is applied by thermal spray technique to the inner and outer surfaces of a quartz crucible used for mono or polycrystalline silicon crystallization processing, inhibiting fusion between the silicon melt and the vitreous silica of the crucible, contamination of the silicon melt by contaminants released from the crucible by devitrification, and any chemical reaction occurring between the crucible and any supporting graphite structure. A powdered form of a suitable protective coating material compatible with high temperature plasma spray techniques, such as magnesium zirconate, barium zirconate, or stabilized zirconium oxide, is fed into a high temperature and high speed plasma jet directed at the crucible. The powder particles are softened or melted in the jet and deposited on the surfaces of the quartz crucible, and allowed to cool and harden into a protective coating.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.