| 摘要 |
<p>A wafer stage (4), which holds a semiconductor wafer (W), is surrounded by a ring (5), for example, consisting of aluminum nitride, which is substantially at the same level of the wafer stage (4). This ring (5) has a buried electrode (52) in the surface. An annular source gas supply (6) is provided over the upper part of the wafer stage (4). The gas supply has its inner face in which an electrode (63) that is exposed in a vacuum container (2). Just before the plasma generation is stopped, a positive voltage is applied to the electrodes (52, 63), which serve to collect particles confined in the container when the plasma disappears.</p> |
