PNICTIDE TRAP FOR VACUUM SYSTEMS

摘要

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 P4 into other species such as P2 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.