Crucible weight measurement system for controlling feedstock introduction in Czochralski crystal growth
US8257496B1 · kind B1 · utility
3Cited by
0References
4Claims
0Family size
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Key dates
| Filing date | Dec 3, 2008 |
| Grant date | Sep 4, 2012 |
| Priority date | — |
| Expiry date | Nov 24, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1056
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A weighing system is provided for a continuous Czochralski process that accurately measures the weight of the crucible and melt during crystal growth to control the introduction of feedstock in order to keep the weight approximately constant. The system can measure the weight of the crucible while the crucible is rotating, and is insensitive to vibrations of the melt surface as well as variable torques on the crucible shaft induced by the rotation. The system also measures the weight of the crucible and its contents in order to control the amount of feedstock recharged after an ingot is withdrawn.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.