Apparatus of plural charged-particle beams
AssigneeASML Netherlands B.V.
InventorsWeiming Ren, Shuai Li, Xuedong Liu, Zhongwei Chen
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Abstract
A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit changes a single electron source into a virtual multi-source array, a primary projection imaging system projects the array to form plural probe spots on the sample, and a condenser lens adjusts the currents of the plural probe spots. In the source-conversion unit, the image-forming means is on the upstream of the beamlet-limit means, and thereby generating less scattered electrons. The image-forming means not only forms the virtual multi-source array, but also compensates the off-axis aberrations of the plurality of probe spots.
Claims19
A charged-particle beam apparatus, comprising:
- an image-forming unit configured to form a plurality of images of a charged particle source using a plurality of beamlets of a primary beam, the image-forming unit comprising a first layer of multi-pole elements and a second layer of multi-pole elements, wherein the multi-pole elements of the first layer are aligned with the multi-pole elements of the second layer in a direction parallel to a primary optical axis of the apparatus;
- a first projection system configured to form a plurality of probe spots on a sample from the plurality of beamlets of the primary beam;
- a second projection system configured to focus a plurality of secondary beams generated by the plurality of probe spots on the sample;
- and
- a detection device configured to receive the plurality of secondary beams.
Dependencies are inferred from the claim text.