Ultrapure purification process and ultrapure purification system for nitrogen, argon and oxygen

Abstract

The invention relates to purification of bulk gases in the manufacturing field of semiconductor chips. An ultrapure purification process for nitrogen, argon and oxygen comprises the following steps: catalytic oxidation procedure: adopting an oxidation catalyst with metal oxide as a carrier to load palladium; heating raw gas to 300 DEG C, then enabling the heated gas to enter a catalytic reactor, and oxidizing methane, carbon monoxide, hydrogen and non-methane in the raw gas by an oxidation catalyst; adsorption procedure: enabling gas which is treated by the catalytic oxidation procedure and only contains three impurities, namely oxygen, water and carbon dioxide, to enter the subsequent adsorption procedure for purifying, adsorbing the oxygen, the water and the carbon dioxide by deoxidizerpurification, and removing the oxygen, the water and the carbon dioxide to below 1 ppb. The process disclosed by the invention is simple and no excess oxygen is needed to be additionally added into the raw gas, so that the regeneration period of the adsorption procedure is effectively prolonged; a deoxidizer has high adsorption capacity for the oxygen, the water and the carbon dioxide, and therefore, the operation cost of a purifier is reduced.

Description

technical field [0001] The invention relates to the purification of bulk gases used in the field of semiconductor chip manufacturing, in particular to a purification system for nitrogen, argon and oxygen. technical background [0002] The demand for nitrogen, argon, oxygen and other bulk gases in the semiconductor chip manufacturing process mainly comes from cryogenic air separation, in which the content of oxygen, water, carbon dioxide, carbon monoxide, hydrogen and non-methane hydrocarbons as impurities is at the ppm level, and the chip In the manufacturing process, the content of various impurities is generally required to be below 1ppb, so further purification of the bulk gas is required to meet the process requirements. [0003] In the current adsorption process purification, only oxygen, water, and carbon dioxide can be removed. If carbon monoxide, hydrogen, methane and non-methane hydrocarbons need to be further removed, a catalytic oxidation process needs to be added...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the catalytic oxidation plus normal temperature adsorption process used in the prior art for gas purification ensures that the catalytic oxidation reaction can proceed smoothly, but the excess oxygen added to the raw material gas will seriously consume the adsorption capacity of the back-end adsorption process. Capacity, thereby shortening the regeneration cycle of the adsorption process, improving the operating cost of the purifier, providing a nitrogen, argon, oxygen ultra-pure purification process, using a suitable catalyst in the catalytic process, so that the catalytic oxidation process does not react It is necessary to add oxygen in the feed gas to prolong the regeneration cycle of the adsorption process and reduce the purification operation cost

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