Vitreous silica crucible having transparent layer, bubble-containing layer, and semi-transparent layer in its wall, method of manufacturing the same, and method of manufacturing silicon ingot
US9157168B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 2011 |
| Grant date | Oct 13, 2015 |
| Priority date | — |
| Expiry date | Jul 2, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1032
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Provided is a vitreous silica crucible which can suppress inward sagging and buckling of the sidewall effectively even when time for pulling silicon ingots is extremely long. According to the present invention, provided is a vitreous silica crucible for pulling a silicon single crystal, wherein the crucible has a wall comprising, from an inner surface toward an outer surface of the crucible, a transparent vitreous silica layer having a bubble content rate of less than 0.5%, a bubble-containing vitreous silica layer having a bubble content rate of 1% or more and less than 50%, a semi-transparent vitreous silica layer having a bubble content rate of 0.5% or more and less than 1.0% and having an OH group concentration of 35 ppm or more and less than 300 ppm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.