Method for controlling convection pattern of silicon melt and method for producing monocrystalline silicon
US11186921B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2019 |
| Grant date | Nov 30, 2021 |
| Priority date | — |
| Expiry date | Feb 27, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B30/04
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method of controlling a convection pattern of a silicon melt includes: acquiring a temperature at a first measurement point not overlapping a rotation center of a quartz crucible on a surface of the silicon melt, the quartz crucible rotating in a magnetic-field-free state; determining that the temperature at the first measurement point periodically changes; and fixing a direction of a convection flow to a single direction in a plane orthogonal with an application direction of a horizontal magnetic field in the silicon melt by starting a drive of a magnetic-field applying portion to apply the horizontal magnetic field to the silicon melt when a temperature change at the first measurement point reaches a predetermined state, and subsequently raising the intensity to 0.2 tesla or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.