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.
Claims9
A multi-beam apparatus for observing a surface of a sample, the apparatus comprising:
- an electron source that is a source of electrons of an electron beam and that is aligned with a primary optical axis of the apparatus;
- and
- an adjustable collimating lens having a principal plane and configured to change paths of the electrons of the electron beam, wherein the adjustable collimating lens is aligned with the primary optical axis, and wherein the principal plane is moveable along the primary optical axis to vary currents of a plurality of beamlets that are derived from the electron beam.
Dependencies are inferred from the claim text.