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US 2018/0323034 A1Published application
Reduced Coulomb Interactions in a Multi-Beam Column
AssigneeKLA-Tencor Corporation
InventorAlan D. Brodie
Life of this patent
Estimating the term…
Abstract
Performance of a multi-electron-beam system can be improved by reducing Coulomb effects in the illumination path of a multi-beam inspection system. A beam-limiting aperture with multiple holes can be positioned between an electron beam source and a multi-lens array, such as in a field-free region. The beam-limiting aperture is configured to reduce Coulomb interactions between the electron beam source and the multi-lens array. An electron beam system with the beam-limiting aperture can be used in a scanning electron microscope.
Claims20
An electron beam system comprising:
- an electron beam source;
- a multi-lens array;
- a beam-limiting aperture that defines a plurality of holes, wherein the beam-limiting aperture is disposed between the electron beam source and the multi-lens array, and wherein the beam-limiting aperture is configured to reduce Coulomb interactions between the electron beam source and the multi-lens array;
- elements on the opposite side of the multi-lens array from the electron source, wherein the elements are configured to adjust focus of beamlets from the multi-lens array;
- and
- a magnetic lens disposed between the multi-lens array and the elements.
3 more elements
A method comprising:
- generating an electron beam;
- extracting the electron beam;
- directing the electron beam through a beam-limiting aperture that defines a plurality of holes;
- directing the electron beam through a multi-lens array positioned downstream of the beam-limiting aperture with respect to a projection direction of the electron beam, wherein the beam-limiting aperture is configured to reduce Coulomb interactions between the electron beam source and the multi-lens array;
- directing the electron beam through a magnetic lens positioned downstream of the multi-lens array with respect to the projection direction of the electron beam;
- directing the electron beam through elements positioned downstream of the magnetic lens with respect to the projection direction of the electron beam, wherein the elements are configured to adjust focus of beamlets from the magnetic lens;
- and
- focusing the beamlets from the magnetic lens with the elements.
5 more elements
A system comprising:
- an electron beam source configured to generate an electron beam;
- a multi-lens array positioned upstream of a wafer;
- a beam-limiting aperture that defines a plurality of holes, wherein the beam-limiting aperture is disposed between the electron beam source and the multi-lens array, and wherein the beam-limiting aperture is configured to reduce Coulomb interactions between the electron beam source and the multi-lens array;
- elements on the opposite side of the multi-lens array from the electron source, wherein the elements are configured to adjust focus of beamlets from the multi-lens array;
- and
- a magnetic lens disposed between the multi-lens array and the elements;
- and
- a detector configured to detect electrons from the electron beam returned from a surface of the wafer.
5 more elements
Dependencies are inferred from the claim text.