Abstract A method of treating a waste gas containing at least boron trichloride and chlorine comprises first treating the waste gas with a treating agent containing a magnesium compound by dry process and then treating the waste gas with a treating agent containing a calcium compound by dry process. Thus, it is possible to remove efficiently a chloride and chlorine containing gas from waste gas discharged from dry etching process or other manufacturing process in the semiconductor industry. In addition, it is possible to reduce the amount of treating agent used, lengthen the treating agent replacing cycle, and facilitate the maintenance of the system.
A method of treating a waste gas containing at least boron trichloride and chlorine, comprising first treating the waste gas with a treating agent containing a magnesium compound packed in a tower and then treating said waste gas with a treating agent containing a calcium compound packed in the same or another tower, the temperature within said tower being in the range of from about 20°C to about 80°C, the waste gas being passed through said tower under a pressure of from about 0.9 atoms to about 2 atoms, and the particle size of the treating agents being about 0.3 mm to about 5.0 mm in diameter.
Claim 2
Independent Claim
107 words
A method of treating a waste gas containing at least boron trichloride and chlorine, comprising first treating the waste gas with a treating agent containing a magnesium compound packed in a tower and then treating said waste gas with a treating agent containing a calcium compound packed in the same or another tower, the temperature within said tower being in the range of from about 20°C to about 80°C, the waste gas being passed through said tower under a pressure of from about 0.9 atoms to about 2 atoms, and the particle size of the treating agents being about 0.3 mm to about 5.0 mm in diameter.
Claim 3
Dependent Claim
47 words
The method of Claim 1, wherein said magnesium compound is selected from the group consisting of magnesium hydroxide, magnesium oxide, magnesium carbonate and a mixture thereof, while said calcium compound is selected from the group consisting of calcium hydroxide, calcium oxide, calcium carbonate and a mixture thereof.
Claim 4
Dependent Claim
31 words
The method of Claim 1 or 2, wherein said waste gas is discharged from a chemical dry etching step using a chloride and/or chlorine containing gas in a semiconductor manufacturing process.