The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 23, 1986
Filed:
Feb. 17, 1984
Robert W Parry, Salt Lake City, UT (US);
John A Baumann, Ossining, NY (US);
Rozalie Schachter, Flushing, NY (US);
Stauffer Chemical Company, Westpoint, CT (US);
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.