Method of producing high-quality silicon single crystals
US6458204B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2000 |
| Grant date | Oct 1, 2002 |
| Priority date | — |
| Expiry date | Nov 22, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B15/305
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method of producing high-quality and large-diameter single crystals by the Czochralski method is disclosed which can provide wafers with a minimized number of such grown-in defects as dislocation clusters and laser scattering tomography defects. Specifically, it is a method of producing silicon single crystals which comprises carrying out the crystal pulling while maintaining the solid-melt interface during pulling in the shape of an upward convex with the central portion of the interface being higher by at least 5 mm than the peripheral region thereof and while applying a magnetic field, and optionally in addition to the above, while maintaining the temperature gradient in the direction of axis of pulling in the peripheral region at a level lower than that in the central portion in the range of from the melting point to 1,200° C. In this case, it is desirable that the portion of the single crystal surface lying at least 50 mm above the melt surface be shielded from direct radiant heat from the heater and/or crucible wall, that a horizontal magnetic field of 0.08 to 0.3 T be applied in parallel with the melt surface or a cusped magnetic field showing an intensity of 0.02 to 0…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.