Patent · US Expired

Pnictide trap for vacuum systems

US4746500A · kind A · utility

1Cited by
1References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 16, 1986
Grant dateMay 24, 1988
Priority date
Expiry dateJul 16, 2006

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB01J2219/0894
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.