Crystal pulling methods and apparatus
US5879448A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1997 |
| Grant date | Mar 9, 1999 |
| Priority date | — |
| Expiry date | Jun 26, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1072
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method and an apparatus for pulling a single crystal are disclosed. A first neck portion, a convex portion, and a second neck portion are formed in this order under a seed crystal held by a seed chuck, and subsequent to the second neck portion, a single crystal having a diameter-expanding portion and a straight cylindrical portion is formed. Lifting holders are brought around and in proximity to the second neck portion when the second neck portion rises to a predetermined position during the pulling by the seed chuck. The single crystal and the lifting holders are moved relative to each other in the vertical direction to thereby bring the convex portion into contact with the lifting holders in a resting manner, so that part of a load borne by the seed chuck is shifted to the lifting holders. Subsequently, the pulling operation is performed by the lifting holders. Accordingly, a single crystal having a larger weight can be pulled safely while maintaining high quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.