Polycrystal silicon rod and production process therefor
US5976481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 1998 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Jan 20, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B29/06
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A polycrystal silicon rod characterized in that it has a half value width of a peak indicative of crystal orientation (111) of an X-ray diffraction pattern, of 0.3.degree. or less, an internal strain rate in a radial direction of less than 5.0.times.10.sup.-5 cm.sup.-1 and an internal iron concentration of 0.5 ppba or less. The above polycrystal silicon rod having high crystallinity, high purity and low internal strain is produced by heating a core material in a gaseous atmosphere comprising trichlorosilane and hydrogen to deposit silicon on the silicon core material to produce a polycrystal silicon rod, and subjecting the polycrystal silicon rod to a heat treatment without allowing it to contact with the air, to remove strain contained therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.