Apparatus and method for purification of corrosive gas streams

Abstract

A process, composition and apparatus for the removal of impurities from corrosive gases, particularly halogen-containing gases, down to about 100 ppb concentration are described. The critical component is zirconia (ZrO2), which in a variety of physical forms is capable of dehydrating such gases. The zirconia can be in the form of a coating on a substrate, as a granular bulk material, or deposited within the pores of a porous body. The zirconia is retained in a simple container which is easily installed in a gas supply line, such as to a gas- or vapor-deposition manufacturing unit. The purification process can be operated for long periods of time in the presence of these gases. The invention provides final purification to gas streams intended for gas- or vapor-deposition formation of high purity electronic, prosthetic or similar products, and can be used in combination with a preliminary dehydration process or a solid particulate removal unit upstream.

Description

[0001] related application [0002] This application claims the benefit of US Provisional Application 60 / 480,709, filed June 23,2003. The entire teaching of the above application is hereby incorporated by reference. Background technique [0003] Water is the most common and most difficult, if not desirable, impurity to remove from gases. Of course water is ubiquitous in almost all surrounding environments. Even nominally "dry" systems often contain significant amounts of water, and most drying methods can only reduce the water content of the gas to "minimum" values ​​still in the parts per million (ppm) range ". However, since moisture levels in the ppm range are very acceptable for many purposes, there are many patents and articles in the literature dealing with this type of "ppm drying process". [0004] However, in the production of many electronic products such as high-purity wafers, chips, integrated circuits or ceramics, deposition gases with water contents in the pp...

AI Technical Summary

Problems solved by technology

The methods that are being used are usually very expensive due to the very short lifespan of the dewatering materials which necessitates their frequent replacement

Additionally, since it is difficult to determine the exact rate of degradation of dehydration materials in the presence of corrosive halogen and halide gases, users of such dehydration materials must schedule their scrapping and replacement for less than the shortest expected lifespan

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