Pnictide trap for vacuum systems
US4613485A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1984 |
| Grant date | Sep 23, 1986 |
| Priority date | — |
| Expiry date | Feb 17, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2219/0894
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention provides a trap for a vapor species, particularly a pnictide.sub.4 vapor species, for a vacuum system of the type including a vacuum chamber communicating with a forepump through a vacuum line. The trap may be positioned within the vacuum chamber itself, or in the alternative, the trap may be located between the vacuum chamber and the forepump. The trap includes a housing for a cracker, which may be a heated filament or a plasma, which cracks the pnictide vapor species into pnictide.sub.2. The walls of the housing are cooled so that the trapped pnictide species readily forms a film and adheres to the walls of the housing. The pnictide.sub.4 vapor species, which may be harmful to the operation of a forepump, is prevented from entering the forepump. A removable sleeve can be positioned in the housing so that the cracked species adheres to it. The sleeve may be removed from the housing for maintenance and replacement purposes. When the trap is located within the vacuum chamber itself, it also functions to reduce background pnictide.sub.4 pressure in that chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.