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US 2025/0112017 A1Published application
Imaging thousands of electron beams during workpiece inspection
OwnerXinrong Jiang, Youfei Jiang +1inventors
InventorsXinrong Jiang, Youfei Jiang, Luca Grella
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Abstract
Beamlets are generated from the electron beam using an aperture array downstream of the single global collimated lens. The beamlets are directed through an image lens array in a path of the beamlets downstream of the aperture array that individually focuses the beamlets onto the intermediate image plane with the image lens array. The beamlets are then directed at a workpiece on a stage using a transfer lens array downstream of the image lens array. A path of the beamlets does not include a crossover.
Claims25
A system comprising:
- an electron source that emits an electron beam;
- a stage configured to hold a workpiece;
- a single global magnetic lens in a path of the electron beam;
- a global beam-limiting aperture in the path of the electron beam downstream of the single global magnetic lens;
- a single global collimated lens in the path of the electron beam downstream of the global beam-limiting aperture, wherein the single global collimated lens is configured to focus the electron beam;
- an aperture array in the path of the electron beam downstream of the single global collimated lens, wherein the aperture array is configured to generate a plurality of beamlets from the electron beam, wherein the aperture array is illuminated telecentrically by the electron beam, and wherein the plurality of beamlets includes at least 1000 of the beamlets;
- an image lens array in a path of the beamlets downstream of the aperture array, wherein the beamlets are individually focused by the image lens array onto the intermediate image plane;
- and
- a transfer lens array in the path of the beamlets downstream of the image lens array, wherein the beamlets are directed at the workpiece on the stage using the transfer lens array, wherein the path of the beamlets does not include a crossover.
6 more elements
A method comprising:
- emitting an electron beam with an electron source;
- directing the electron beam through a single global magnetic lens;
- directing the electron beam through a global beam-limiting aperture downstream of the single global magnetic lens;
- directing the electron beam through a single global collimated lens in the path of the electron beam downstream of the global beam-limiting aperture whereby the electron beam is focused by the single global collimated lens;
- generating a plurality of beamlets from the electron beam using an aperture array downstream of the single global collimated lens, wherein the plurality of beamlets includes at least 1000 of the beamlets, and wherein the aperture array is illuminated telecentrically by the electron beam;
- directing the beamlets through an image lens array in a path of the beamlets downstream of the aperture array thereby individually focusing the beamlets onto the intermediate image plane with the image lens array;
- and
- directing the beamlets at a workpiece on a stage using a transfer lens array downstream of the image lens array, wherein a path of the beamlets does not include a crossover.
5 more elements
Dependencies are inferred from the claim text.