Single crystal manufacturing apparatus and method
US8216371B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2007 |
| Grant date | Jul 10, 2012 |
| Priority date | — |
| Expiry date | Nov 27, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1088
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A Czochralski single crystal manufacturing apparatus uses multiple heaters to improve the controllability of crystal diameter. The power supplied to the multiple heaters is controlled so as to bring the pulling up speed close to a predetermined speed set value, and so as to bring the heater temperatures close to predetermined target temperature values. The ratio of electrical power between the heaters is controlled to agree with a predetermined power ratio set value which varies according to the crystal pulling up length, and the heater temperatures change along with this change, which causes disturbance to the diameter control. To compensate for this, heater temperature changes along with the power ratio set value change are taken into account in advance in the temperature set values. Accordingly, along with change of the power ratio set value, the temperature set values change to values appropriate for the current power ratio set value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.