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:
May. 24, 1988
Filed:
Jul. 16, 1986
Applicant:
Inventors:
Robert W Parry, Salt Lake City, UT (US);
John A Baumann, Ossining, NY (US);
Rozalie Schachter, Flushing, NY (US);
Assignee:
Stauffer Chemical Company, Westport, CT (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
423322 ; 423210 ; 423659 ;
Abstract
A fore line trap is located before the forepump in a vacuum system. The trap utilizes a cracker, which may be a heated filament or a plasma, and cold walls. The cracker cracks pnictide gas species such as P.sub.4 into other species such as P.sub.2 which have a higher sticking co-efficient. The pnictides are deposited on the cold walls. The cold walls preferably comprise a sleeve which may be removed from the trap and replaced by a clean one.