Apparatus for generating a plurality of beamlets
AssigneeMapper Lithography IP B.V.
InventorPieter Kruit
Life of this patent
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Abstract
The invention relates to an apparatus for generating a plurality of charged particle beamlets, comprising a charged particle source for generating a diverging charged particle beam, a converging means for refracting said diverging charged particle beam and a lens array comprising a plurality of lenses, wherein said lens array is located between said charged particle source and said converging means. In this way, it is possible to reduce aberrations of the converging means.
Claims16
An apparatus for generating a plurality of charged particle beamlets, comprising:
- a charged particle source for generating a diverging charged particle beam
- a lens array comprising a plurality of lenses,
- said lens array further comprising an aperture plate, and means for defining an equipotential surface at a distance from said aperture plate at a different potential than said aperture plate itself.
The apparatus of the preceding claim, wherein the aperture plate has a electrically conducting surface and means for defining the electrostatic potential of said surface.
The apparatus of the preceding claim, wherein said means for defining an equipotential surface comprises a plate having a through hole at the location of the beam of beamlets, in particular a circular hole having its center at the optical axis of the charged particle beam.
The apparatus of the preceding claim, wherein said means for defining an equipotential surface are located between said source and said lens array.
The apparatus of the one but preceding claim, wherein said means for defining an equipotential surface are located between an array of converging elements and a converging means.
Dependencies are inferred from the claim text.