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R. TORRES, D. FRAENKEL, J. VININSKI, E. HENNIG, T. WATANABE, & V. HOULDING,
Matheson Gas Products, Longmont, CO, USA

ABSTRACT

Purification of high-pressure corrosive gases has traditionally utilised a pressure regulator prior to introduction into the purifier. However, reported regulator failures have been shown to be a major disadvantage of using this conventional configuration. Such failures are a great concern owing to the damage they may cause to downstream components such as pressure transducers, mass flow controllers, and on-line monitors. A high-pressure source gas purifier installed before the regulator offers a solution to this common problem. Recently, a new purifier for corrosive gases has been developed that can be used up to full cylinder pressure for source gas purification. This new purifier can also be used at lower pressure for point-of-use purification at the wafer tool. The new purifier reduces moisture concentrations in high- or low-pressure corrosive gases to ppb levels. It has remarkably higher moisture capacity than the first-generation products. The effect of the high-pressure purifier was investigated under severely corrosive gas conditions. HBr was doped with moisture at concentrations from 1 to 5500 and sent through the experimental gas manifold at pressures of 320 psig (HBr cylinder pressure) and 30 psig. Several line valves and gas sticks were placed upstream and downstream of the purification media. After 18 days of exposure to the corrosive environment, the test components were measured for particles, leak rates, and visual corrosion. The results of this investigation are presented to illustrate the effect of the high-pressure purifier on gas distribution components.