Apparatus of plural charged-particle beams
AssigneeASML Netherlands B.V.
InventorsShuai Li, Weiming Ren, Xuedong Liu, Juying Dou, Xuerang Hu, Zhongwei Chen
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Abstract
A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.
Claims18
A pre-beamlet-forming aperture array comprising:
- multiple beamlet-forming apertures configured to cut off a portion of electrons of a primary electron beam emitted by an electron source to form a set of multiple electron beamlets,
- wherein the pre-beamlet-forming aperture array is configured to be positioned proximate to the electron source and between the electron source and a source-conversion unit, and the source-conversion unit is configured to manipulate the set of multiple electron beamlets.
A multi-beam apparatus for observing a surface of a sample, comprising:
- an electron source configured to emit a primary electron beam;
- a pre-beamlet-forming aperture array comprising multiple beamlet-forming apertures configured to cut off a portion of electrons of the primary electron beam to form a set of multiple electron beamlets, and
- a source-conversion unit configured to manipulate the set of multiple electron beamlets,
- wherein the pre-beamlet-forming aperture array is positioned proximate to the electron source and between the electron source and the source-conversion unit.
Dependencies are inferred from the claim text.