Purification of electronic specialty gases by vapor phase transfilling

摘要

A method for purifying liquefied corrosive gases of metallic impurities is described. The principle for this purification method relies on vapor-phase transfilling the vapor phase from a source container into a receiving container. This method has been observed to decrease metal concentrations by a factor of at least 1000 and decreases the metallic impurity levels in the resulting condensate. The vapor transfer is accomplished by controlled differential pressure rather than mechanical pumping, thereby generating no particle or metal impurities.