Purification system of trichlorosilane and silicon crystal
US10584035B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 2018 |
| Grant date | Mar 10, 2020 |
| Priority date | — |
| Expiry date | Feb 24, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B35/007
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A system for purifying trichlorosilane that can prevent re-contamination by the dissociation of an adduct occurring in association with the conversion of high boiling point compounds or the remaining of impurities due to an equilibrium constraint is provided. Trichlorosilane containing impurities serving as a donor or an acceptor in silicon crystals is supplied to a multistage impurity conversion step. These impurities in the trichlorosilane are converted into high boiling point compounds in the presence of a distillation aid. A plurality of impurity conversion step sections (101 to 10n) are connected in series, and any of the impurity conversion step sections comprises a reception section a for the trichlorosilane from the preceding stage section, an introduction section b for the distillation aid, a transmission section c for the trichlorosilane to the subsequent stage section, and a drain section d that discharges a remainder out of the impurity conversion step section.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.