摘要 |
Methods and apparatuses for shielding magnetic flux which is associated with a semiconductor fabrication system are provided. A magnetic shield assembly substantially surrounds a side wall of a plasma reactor. The shield assembly comprises a passive shield member in combination with an active shield member. As a result, effective shielding of magnetic flux can occur without excessive distortion of the magnetic field line pattern in the plasma region of the plasma reactor. In one aspect, the shield assembly comprises a first shield member adapted to attenuate a magnetic flux density. The first shield member is disposed in a parallel, spaced apart relationship from the side wall. A second member is attached to the first shield member and is constructed of a ferromagnetic material which is permanently magnetized.
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