| 摘要 |
<p>PURPOSE:To efficiently treat waste gas, by a method wherein a magnetic field applying device is provided to form an electric field and a magnetic field crossing at a specific angle to each other in a discharge tube and the waste gas is allowed to flow through the crossing space to efficiently advance plasma reaction even in the waste gas of minute concn. CONSTITUTION:Waste gas containing a noxious substance such as silane discharged when a semiconductive device is prepared by plasma etching is introduced into a gas flowing space 10 in a discharge pipe from a gas introducing port 4. When an AC or DC magnetic flux 6 crossing the direction of the electric field formed by a pair of electrodes 1, 2-connected to a DC or AC power source at an angle of about 45-135 deg.C is applied to the space 10 by an electromagnetic or a permanent magnet, discharge is generated and a gas or vapor of silane is formed into plasma to be changed to silicon and hydrogen. Hydrogen generated is discharged from a gas lead-out port 5. The solid product such as silicon diposited in the discharge pipe is taken out of the tube by preliminarily covering the surfaces of the electrodes with a metal foil and covering the other part with an insulating film and replacing the covered ones.</p> |
