Charged Particle Extraction Device and Method of Design There for
AssigneeFEI Company
InventorsRoderick Boswell, Orson Sutherland
Life of this patent
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Abstract
The present invention provides a method for extracting a charged particle beam from a charged particle source. A set of electrodes is provided at the output of the source. The potentials applied to the electrodes produce a low-emittance growth beam with substantially zero electric field at the output of the electrodes.
Claims21
A low emittance growth extractor for extracting particles from a particle source to form a charged particle beam, comprising:
- a first electrode closest to the plasma source with an aperture through which particles can be extracted to form a beam, the particle source forming a meniscus in the vicinity of the aperture with a substantial electric field at the meniscus;
- wherein the beam flows through the aperture of a second electrode with an electric field magnitude in the vicinity of the aperture of the second electrode that is substantially greater than the electric field magnitude at the meniscus;
- and
- wherein the beam flows through the aperture of a third electrode with an electric field magnitude in the vicinity of the aperture of the third electrode that is substantially smaller than the electric field magnitude at the meniscus.
A low emittance growth extractor for extracting particles from a particle source to form a beam, comprising:
- a particle source providing a source of particles to form a particle beam;
- a first region with an entrance for receiving particles from the source, having a high potential and substantial electric field at its entrance, and a low potential with substantially zero electric field at its exit;
- and
- a second region with the exit of the first region being the entrance to the second region and with the second region having zero potential and substantially zero electric field at its exit;
- thereby providing a beam having little or no emittance growth as it traverses the extractor.
A method of manufacturing a set of electrodes to extract a particle beam from a particle source, comprising:
- providing a source of particles to form a particle beam;
- providing a sequence of electrodes that exhibit potentials to produce a beam that flows through the apertures of the electrodes with a substantially zero electric field at an exit aperture of the sequence of electrodes.
21-29. (canceled)
Dependencies are inferred from the claim text.