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US 2004/0175953 A1Published application
Apparatus for generating planar plasma using concentric coils and ferromagnetic cores
OwnerJohn S. Ogleinventor
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Abstract
A plasma source using a combination of concentric coils and ferromagnetic cores drives a radio frequency magnetic flux with controlled radial magnitude variation through a window into a reduced pressure process chamber, to provide improved plasma generation efficiency and ease of process uniformity adjustment.
Claims5
A plasma source for generating a plasma in a reduced pressure process chamber, comprising:
- a window for passing varying magnetic flux into said reduced pressure process chamber,
- a first coil for magnetic flux confinement, consisting of at least one shorted turn,
- a second coil inside said first coil, for magnetic flux generation,
- means for applying radio frequency voltage across said second coil to generate radio frequency varying magnetic flux through the interior of said second coil, part of said radio frequency varying magnetic flux passing through said window into said reduced pressure process chamber,
- at least one return path ferromagnetic core placed between said first coil and said second coil to reduce the magnetic reluctance of the return magnetic flux path, and
- at least one uniformity adjustment ferromagnetic core placed inside said second coil.
3 more elements
Dependencies are inferred from the claim text.