Multi-beam inspection methods and systems
AssigneeASML Netherlands B.V.
InventorPieter Willem Herman DE JAGER
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Abstract
Systems, methods, and programming are described for inspecting a substrate having a pattern imaged thereon, including obtaining a plurality of selected target locations on the substrate, the selected target locations dependent on characteristics of the pattern, scanning the substrate with a plurality of electron beamlets, wherein the scanning includes individually addressing the beamlets to impinge on the selected target locations independently, detecting a reflected or a transmitted portion of the beamlets, and generating images of the selected target locations.
Claims20
An apparatus for inspecting a substrate having a pattern thereon, the apparatus comprising:
- a condenser lens configured to receive a plurality of electron tho beamlets and reduce a divergence thereof;
- a scan deflector configured and arranged to displace the beamlets as a group to scan a surface of the substrate;
- an objective lens configured and arranged to focus the beamlets onto the surface of the substrate;
- and
- an addressable deflector configured and arranged to independently displace each beamlet to impinge on a selected target location such that at least one beamlet changes pitch with respect to its nearest neighbors for generating an irregular grid on the surface of the substrate.
A method of inspecting a substrate having a pattern imaged thereon, the method comprising:
- obtaining a plurality of selected target locations on the substrate;
- scanning the substrate with a plurality of electron beamlets, wherein the scanning comprises individually addressing the beamlets to impinge on the selected target locations independently such that at least one beamlet changes pitch with respect to its nearest neighbors for generating an irregular grid on the surface of the substrate;
- and
- detecting reflected, transmitted, or secondary electrons of the beamlets and generating images of the selected target locations.
A computing device including memory and at least one processor, the at least one processor being operable to control an inspection device to at least:
- obtain a plurality of selected target locations on a substrate;
- scan the substrate with a plurality of electron beamlets, wherein the scanning comprises individual addressing of the beamlets to impinge on the selected target locations independently such that at least one beamlet changes pitch with respect to its nearest neighbors for generating an irregular grid on the surface of the substrate;
- and
- detect reflected, transmitted, or secondary electrons of the beamlets and generate images of the selected target locations.
Dependencies are inferred from the claim text.