Apparatus of plural charged-particle beams
AssigneeHermes Microvision, Inc.
InventorsWeiming Ren, Shuai Li, Xuedong Liu, Zhongwei Chen
Life of this patent
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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.
Claims13
A charged-particle beam apparatus, comprising:
- a charged particle source configured to provide a primary beam;
- an image forming unit configured to form a plurality of images of the charged particle source using a plurality of beamlets of the primary beam;
- a first projection system including a transfer lens and an objective lens, wherein the transfer lens is configured to focus the plurality of beamlets, and wherein the objective lens is configured to receive the focused plurality of beamlets and form a plurality of probe spots on a sample from the plurality of beamlets;
- a second projection system configured to focus a plurality of secondary beams generated by the plurality of probe spots on the sample;
- a beam separator configured to separate the plurality of beamlets and the plurality of secondary beams;
- and
- a detection device with a plurality of detection elements configured to receive the plurality of secondary beams,
- wherein the second projection system includes an anti-rotation magnetic lens configured to minimize a rotation of the plurality of secondary beams directed to the detection device.
Dependencies are inferred from the claim text.