Crucible for pulling silicon single crystal
US5720809A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 1995 |
| Grant date | Feb 24, 1998 |
| Priority date | — |
| Expiry date | Aug 2, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1052
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A double-wall crucible is disclosed which is constructed by coaxially disposing a cylindrical partition wall in an outer crucible for holding a molten mass of silicon as a raw material and operated by heating the outer crucible and meanwhile supplying the raw material silicon to the gap between the outer crucible and the cylindrical partition wall and introducing the consequently produced molten mass of silicon to the interior of the cylindrical partition wall through a passage below the level of the molten mass of silicon interconnecting the outer crucible and the inner side of the cylindrical partition wall and meanwhile pulling a single crystal bar from the molten mass of silicon in the cylindrical partition wall. In this double-wall crucible, at least the cylindrical partition wall is formed of quartz glass having a hydroxyl group (OH group) content of not more than 30 ppm. In the crucible of this invention, the produced silicon single crystal enjoys improved quality and the operation of pulling enjoys enhanced yield because the cylindrical partition wall is softened or deformed only sparingly by the intense heat emanating from the molten mass of silicon. Since the cylindrical …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.