Czochralski growth of randomly oriented polysilicon and use of randomly oriented polysilicon dummy wafers
US8486835B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Sep 18, 2009 |
| Grant date | Jul 16, 2013 |
| Priority date | — |
| Expiry date | Apr 7, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24355
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Non-production wafers of polycrystalline silicon are placed in non-production slots of a support tower for thermal processing monocrystalline silicon wafers. They may have thicknesses of 0.725 to 2 mm and be roughened on both sides. Nitride may be grown on the non-production wafers to a thickness of over 2 μm without flaking. The polycrystalline silicon is preferably randomly oriented Czochralski polysilicon grown using a randomly oriented seed, for example, CVD grown silicon. Both sides are ground to introduce sub-surface damage and then oxidized and etch cleaned. An all-silicon hot zone of a thermal furnace, for example, depositing a nitride layer, may include a silicon support tower placed within a silicon liner and supporting the polysilicon non-production wafers with silicon injector tube providing processing gas within the liner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.