Method for pulling up single crystal
US7431764B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 2006 |
| Grant date | Oct 7, 2008 |
| Priority date | — |
| Expiry date | Apr 14, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1008
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The axial temperature gradient G at the vicinity of the solid-liquid interface 24 in an ingot is calculated in consideration of the heating value of a heater 18, the dimensions and physical property values of furnace inside components and the convection of the melt 12 before pulling up the single crystal ingot 15 by a puller 10 by use of a numerical simulation of synthetic heater transfers and a numerical simulation of melt convection. Then, the pulling velocity V of the single crystal ingot is determined from an value experienced of the ratio C=V/G of the pulling velocity V and the axial temperature gradient G of the single crystal ingot at which the single crystal ingot becomes defect-free, obtained when the single crystal ingot was pulled up by a same type puller as the puller in the past, and the axial temperature gradient G calculated by use of the simulations. Then, the ingot is pulled up at the pulling velocity, and the change value of the temperature gradient G to the deterioration value of partial furnace inside components roughly measured while the ingot is pulled up is roughly forecasted by use of the simulations. And further, the pulling velocity V of the ingot is adjus…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.