| 摘要 |
PURPOSE:To prevent the generation of various abnormal modes of plasma by a method wherein the plasma is confined in the expected vacant space. CONSTITUTION:An insulative barrier member 10 is provided surrounding a pair of electrodes 3 and 3. The height L (the length along the direction astriding both electrodes 3 and 3) of the barrier member 10 exceeds the distance H between the two electrodes, the inside diameter R of the barrier member 10 is larger than the electrode diameter W, and the two electrodes 3 and 3 are housed therein. Also, the gap (d) between the circumferential part of the two electrodes 3 and 3 and the corresponding inner face part of the barrier member 10 is provided to let out raw gas as shown by the arrow (fr) in the diagram, but the actual measurements can be set at an experimentally suitable value. The gap (d) is 50mm or less in general, but desirably, it is 20mm or less, and an aperture or a part to be used for evacuation of air is provided separately on the barrier member 10 and the electrode 3. However, in the case where the length L of the barrier member 10 is shorter than the distance H between the electrodes, it is better to have D=0 without having the gap. |
