Method of adjusting concentration of oxygen in silicon single crystal and apparatus for use in the method
US5269875A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1992 |
| Grant date | Dec 14, 1993 |
| Priority date | — |
| Expiry date | Jan 24, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1072
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Used in a Si crystal pulling apparatus using the Czochralski method, to lower the concentration of oxygen in the Si single crystal without increasing the production cost and to make the concentration substantially even all over the Si single crystal. The crystal 36 is produced by disposing a straightening tube 40 concentrically with and above a quartz crucible 22, letting inert gas flow down through the tube, dipping a seed crystal in Si molten liquid 28 in the quartz crucible and then pulling the seed crystal up. The concentration of oxygen in the Si single crystal is adjusted by controlling the distance H between the surface of the Si molten liquid and the bottom end of the straightening tube in accordance with the pull-up length Y or the pull-up time from a certain growth point of the crystal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.