Inert gas recovery and recycle for silicon crystal growth pulling process
US9114989B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 2012 |
| Grant date | Aug 25, 2015 |
| Priority date | — |
| Expiry date | Oct 21, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02C20/40
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
This invention is directed to a method for recovering, purifying and recycling an inert gas on a continual basis in connection with a silicon crystal pulling process. Silicon oxide impurities generated during the crystal growth process are completely oxidized by in-situ oxidation with a regulated amount of an oxidizing source gas mixture to form silicon dioxide impurities, which can be removed by a particulate removal device. The particulate-free effluent enters a purification unit to remove the remaining impurities. The inert gas emerging from the purification unit can be fed back into the crystal puller apparatus and/or mixed with the oxidizing source gas mixture. As a result, the ability to increase silicon crystal throughput, quality and at the same time reduce the costs associated with recycling the inert gas can be achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.