Two camera diameter control system with diameter tracking for silicon ingot growth
US6030451A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 1998 |
| Grant date | Feb 29, 2000 |
| Priority date | — |
| Expiry date | Jan 12, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1008
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method and apparatus for measuring and controlling the diameter of a silicon single crystal ingot grown by the Czochralski technique using dual optical cameras focused on diametrically opposed edges of the meniscus of the growing crystal to measure the actual crystal diameter. The crystal growth parameters can be adjusted in response to the measured diameter to maintain a constant, desired diameter. The method and apparatus of the invention provide a continuous accurate measurement of the crystal diameter and avoid unnecessary adjustments to the crystal growth conditions resulting from diameter measurement errors due to the effects of crystal orbit, melt level changes and camera angle variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.