Particle-Optical Systems and Arrangements and Particle-Optical Components for such Systems and Arrangements
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Accused Products
Abstract
The present invention concerns a charged-particle multi-beamlet system that comprises a source of charged particles (301); a first multi-aperture plate (320) having plural apertures disposed in a charged particle beam path of the system down-stream of the source; a first multi-aperture selector plate (313) having plural apertures; a carrier (340), wherein the first multi-aperture selector plate is mounted on the carrier; and an actuator (350) configured to move the carrier such that the first multi-aperture selector plate is disposed in the charged particle beam path of the system downstream of the source in a first mode of operation of the system, and such that the first multi-aperture selector plate is disposed outside of the charged particle beam path in a second mode of operation of the system. The source, the first multi-aperture plate and the carrier of the system are arranged such that a first number of charged particle beamlets is generated at a position downstream of both the first multi-aperture plate and the first multi-aperture selector plate in the first mode of operation, and that a second number of charged particle beamlets is generated at the position in the second mode of operation, wherein the first number of beamlets differs from the second number of beamlets.
51 Citations
45 Claims
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1-26. -26. (canceled)
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27. A charged-particle multi-beamlet system comprising:
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a source of charged particles; a first multi-aperture plate having plural apertures disposed in a charged particle beam path of the system downstream of the source; a first multi-aperture selector plate having plural apertures; a carrier, wherein the first multi-aperture selector plate is mounted on the carrier; an actuator configured to move the carrier such that the first multi-aperture selector plate is disposed in the charged particle beam path of the system downstream of the source in a first mode of operation of the system, and such that the first multi-aperture selector plate is disposed outside of the charged particle beam path in a second mode of operation of the system; a focusing lens disposed in a beam path downstream of both the first multi-aperture plate and the first multi-aperture selector plate; a stage for mounting an object in an object plane disposed downstream of the focusing lens; and a field-separating electrode having an aperture disposed in the charged particle beam path downstream of the focusing lens and upstream of the object plane; wherein the source, the first multi-aperture plate and the carrier are arranged such that a first number of charged particle beamlets is generated at a position downstream of both the first multi-aperture plate and the first multi-aperture selector plate in the first mode of operation, and that a second number of charged particle beamlets is generated at the position in the second mode of operation, wherein the first number of beamlets differs from the second number of beamlets; and wherein the aperture of the field-separating electrode has a diameter such that it is traversed by the first number of beamlets in the first mode of operation and by the second number of beamlets in the second mode of operation. - View Dependent Claims (28, 29, 30, 31, 32, 33, 44)
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34. A charged-particle multi-beamlet system comprising:
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a source of charged particles; a first multi-aperture plate having plural apertures disposed in a charged particle beam path of the system downstream of the source; a first multi-aperture selector plate having plural apertures; a carrier, wherein the first multi-aperture selector plate is mounted on the carrier; an actuator configured to move the carrier such that the first multi-aperture selector plate is disposed in the charged particle beam path of the system downstream of the source in a first mode of operation of the system, and such that the first multi-aperture selector plate is disposed outside of the charged particle beam path in a second mode of operation of the system; a focusing lens disposed in a beam path downstream of both the first multi-aperture plate and the first multi-aperture selector plate; a stage for mounting an object in an object plane disposed downstream of the focusing lens; a field-separating electrode having an aperture disposed in the charged particle beam path downstream of the focusing lens and upstream of the object plane; a first voltage supply configured to supply a first voltage to the first multi-aperture plate such that charged particle beamlets traversing the apertures of the first multi-aperture plate each have a beamlet focus at a distance downstream of the first multi-aperture plate; a second voltage supply configured to supply a second voltage to the field-separating electrode; a third voltage supply configured to supply a third voltage to the object; and a controller configured to control the actuator and the second and third voltage supplies; wherein the source, the first multi-aperture plate and the carrier are arranged such that a first number of charged particle beamlets is generated at a position downstream of both the first multi-aperture plate and the first multi-aperture selector plate in the first mode of operation, and that a second number of charged particle beamlets is generated at the position in the second mode of operation, and wherein the first number of beamlets in the first mode of operation is smaller than the second number of beamlets in the second mode of operation; wherein the aperture of the field-separating electrode has a diameter such that it is traversed by the first number of beamlets in the first mode of operation and by the second number of beamlets in the second mode of operation; and wherein the focusing lens is configured such that the focus of each beamlet is imaged onto the object plane. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 45)
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43. A method, comprising:
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directing a first number of charged particle beamlets onto an object while an electric field applied to a surface of the object has a first field strength; and directing a second number of charged particle beamlets onto the object while the electric field applied to the surface of the object has a second field strength; wherein the first number is smaller than the second number and wherein the first electric field strength is smaller than the second electric field strength.
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Specification