Vitreous silica crucible for pulling silicon single crystal and method of manufacturing the same
US8936685B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2010 |
| Grant date | Jan 20, 2015 |
| Priority date | — |
| Expiry date | Feb 18, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1032
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The present invention provides a vitreous silica crucible which can suppress the sidewall lowering of the crucible under high temperature during pulling a silicon single crystal, and a method of manufacturing such a vitreous silica crucible. The vitreous silica crucible 10 includes an opaque vitreous silica layer 11 provided on the outer surface side of the crucible and containing numerous bubbles, and a transparent vitreous silica layer 12 provided on the inner surface side. The opaque vitreous silica layer 11 includes a first opaque vitreous silica portion 11a provided on the crucible upper portion, and a second opaque vitreous silica portion 11b provided on the crucible lower portion. The specific gravity of the second opaque vitreous silica portion 11b is 1.7 to 2.1, and the specific gravity of the first opaque vitreous silica portion 11a is 1.4 to 1.8, and smaller than that of the second opaque vitreous silica portion. The particle size distribution of the material silica powder for the first opaque vitreous silica portion 11a is wider than that of the second opaque vitreous silica portion 11b, and the material silica powder for the first opaque vitreous silica portion 11a inc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.