Electron beam apparatus, inspection tool and inspection method
AssigneeASML Netherlands B.V.
InventorsErwin Paul Smakman, Albertus Victor Gerardus Mangnus, Maikel Robert Goosen
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Abstract
An electron beam apparatus including: an electron beam source configured to generate an electron beam; a beam conversion unit including an aperture array configured to generate a plurality of beamlets from the electron beam, and a deflector unit configured to deflect one or more groups of the plurality of beamlets; and a projection system configured to project the plurality of beamlets onto an object, wherein the deflector unit is configured to deflect the one or more groups of the plurality of beamlets to impinge on the object at different angles of incidence, each beamlet in a group having substantially the same angle of incidence on the object.
Claims20
An electron beam apparatus comprising:
- an electron beam source configured to generate an electron beam;
- a beam conversion unit comprising:
- an aperture array configured to generate a plurality of discrete beamlets from the electron beam, and
- a deflector unit configured to deflect a plurality of beamlet groups, each group having one or more beamlets selected from the plurality of discrete beamlets;
- and
- a projection system configured to project the plurality of beamlet groups onto an object,
- wherein the deflector unit and the projection system are together configured to deflect and cause the beamlet groups to impinge on the object such that a first net angle of incidence at the object of the electrons in each of the one or more beamlets of a first beamlet group of the plurality of beamlet groups is different than a second net angle of incidence at the object of the electrons in each of the one or more beamlets of a second beamlet group of the plurality of beamlet groups.
A method of inspecting an object, the method comprising:
- generating an electron beam from an electron beam source of an electron beam apparatus;
- generating a plurality of discrete beamlets from the electron beam using an aperture array of the electron beam apparatus;
- deflecting a plurality of beamlet groups, each group having one or more beamlets selected from the plurality of discrete beamlets using a deflector unit of the electron beam apparatus;
- projecting the plurality of beamlet groups onto the object using a projection system of the electron beam apparatus, wherein the deflector unit and the projection system together deflect and cause the beamlet groups to impinge on the object such that a first net angle of incidence at the object of the electrons in each of the one or more beamlets of a first beamlet group of the plurality of beamlet groups is different than a second net angle of incidence at the object of the electrons in each of the one or more beamlets of a second beamlet group of the plurality of beamlet groups;
- detecting a response signal from the object in response to the impinging of the object with the plurality of beamlets;
- and
- processing the response signal to determine a characteristic of the object.
Dependencies are inferred from the claim text.