Method and apparatus for avoiding undesirable deposits in crystal growing operations
US4116642A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1976 |
| Grant date | Sep 26, 1978 |
| Priority date | — |
| Expiry date | Dec 15, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1068
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
In Czochralski crystal growing operations, particularly those involving growth of silicon crystals, projecting formations of silicon monoxide, which sometimes form on the surface of the melt-containing crucible just above the surface of the melt, are avoided by perturbing the formation conditions at the region of probable formation. Such perturbations may include increasing the temperature of the crucible at the region of probable formation. The increase in temperature may be provided by including an aperture in the housing which surrounds and supports the crucible to enable locally greater radiative heating of the crucible in the region of probable formation. Other expedients for locally increasing the temperature of the crucible include, without limitation, selective frosting and other techniques for locally changing the emissivity characteristics of the crucible and/or the surrounding material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.