Process and apparatus for treating gas containing fluorine-containing compounds and CO

Abstract

The purpose of the present invention is to provide a process and an apparatus for efficiently treating a gas containing fluorine-containing compounds and CO to be discharged, for example, from the step of dry cleaning the inner surfaces and the like of a semiconductor manufacturing apparatus or the step of etching various types of formed films such as oxide films in the semiconductor industry. In order to accomplish the above-mentioned purpose, the gas treating process according to the present invention is a process for treating a gas containing fluorine-containing compounds and CO which comprises contacting the above described gas with O 2 and H 2 O at a temperature of 850° C. or higher to oxidize the CO to CO 2 ; and then contacting the gas with γ-alumina at a temperature of 600 to 900° C. to decompose the fluorine-containing compounds.

1 - 2 . (Canceled)  
     
     
         3 . An apparatus for treating a gas containing fluorine-containing compounds and CO which comprises a heat oxidation vessel having a hollow inside enabling the passage of the above described gas therethrough, a heating means capable of heating the temperature of the gas in the hollow inside to 850° C. or higher, a gas inlet, an O 2  inlet and H 2 O inlet; and a catalytic reaction vessel which is under fluid-communicating condition with the heat oxidation vessel and has been filled with γ-alumina.  
     
     
         4 . The apparatus of  claim 3 , wherein the catalytic reaction vessel further has a heating means capable of heating the γ-alumina to 600 to 900° C.  
     
     
         5 . The apparatus of  claim 3 , wherein the γ-alumina has a crystal structure which exhibits diffraction lines having an intensity of 100 or more at five angles of 33°±1°, 37°±1°, 40°±1°, 46°35 1° and 67°±1° of the angles of diffraction 2θmeasured by an X-ray diffraction apparatus.  
     
     
         6 . The apparatus of  claim 3 , wherein the heat oxidation vessel further has a contact auxiliary means for enhancing the contact efficiency of the CO in the gas with O 2  and H 2 O.  
     
     
         7 . The apparatus of  claim 4 , wherein the heat oxidation vessel further has a contact auxiliary means for enhancing the contact efficiency of the CO in the gas with O 2  and H 2 O.  
     
     
         8 . The apparatus of  claim 5 , wherein the heat oxidation vessel further has a contact auxiliary means for enhancing the contact efficiency of the CO in the gas with O 2  and H 2 O.  
     
     
         9 . An apparatus for treating a gas having fluorine-containing compounds and CO, comprising: 
 a heat oxidation vessel having a hollow inside for a passage of the gas therethrough,    a heater for heating the gas in the hollow inside to a temperature of 850° C. or higher and the heated gas contacting with H 2 O and O 2  to oxidize the CO in the hollow inside, and    a catalytic reaction vessel filled with γ-alumina, wherein the catalytic reaction vessel having fluid-communicating with the heat oxidation vessel for receiving the gas passed through the heat oxidation vessel to treat the fluorine-containing compounds with the γ-alumina.