Multiple-beam system for high-speed electron-beam inspection
AssigneeKLA-Tencor Corporation
InventorsLiqun Han, Xinrong Jiang, John D. Greene
Life of this patent
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Abstract
One embodiment disclosed relates to a multiple-beamlet electron beam imaging apparatus for imaging a surface of a target substrate. A beam splitter lens array is configured to split the illumination beam to form a primary beamlet array, and a scanning system is configured to scan the primary beamlet array over an area of the surface of the target substrate. In addition, a detection system configured to detect individual secondary electron beamlets. Another embodiment disclosed relates to a method of imaging a surface of a target substrate using a multiple-beamlet electron beam column. Other features and embodiments are also disclosed.
Claims19
A multiple-beamlet electron beam imaging apparatus for imaging a surface of a target substrate, the apparatus comprising:
- an electron source configured to emit electrons;
- a condensor electron lens configured to focus the emitted electrons from the electron source into an illumination beam;
- a beam splitter lens array configured to split the illumination beam to form a primary beamlet array, wherein the beam splitter lens array comprises a multiple-layer electrostatic lens array stack;
- an objective electron lens configured to focus the primary beamlet array onto the surface of the target substrate so as to produce a secondary electron beamlet array;
- a scanning system configured to scan the primary beamlet array over an area of the surface of the target substrate;
- and
- a detection system configured to detect individual secondary electron beamlets of the secondary electron beamlet array.
A method of imaging a surface of a target substrate using a multiple-beamlet electron beam column, the method comprising:
- emitting electrons into a vacuum chamber;
- focusing the emitted electrons from the electron source into an illumination beam;
- splitting the illumination beam using a multiple-layer electrostatic lens array stack to form a primary beamlet array;
- focusing the primary beamlet array onto the surface of the target substrate using an objective electron-lens so as to produce a secondary electron beamlet array;
- scanning the primary beamlet array over an area of the surface of the target substrate;
- and
- detecting individual secondary electron beamlets of the secondary electron beamlet array.
An automated inspection system for inspecting a surface of a target substrate using a multiple-beamlet electron beam column, the automated inspection system comprising:
- an electron source configured to emit electrons;
- a condensor electron lens configured to focus the emitted electrons from the electron source into an illumination beam;
- a beam splitter lens array configured to split the illumination beam to form a primary beamlet array, wherein the beam splitter lens array comprises a multiple-layer electrostatic lens array stack;
- an objective electron lens configured to focus the primary beamlet array onto the surface of the target substrate so as to produce a secondary electron beamlet array;
- a scanning system configured to scan the primary beamlet array over an area of the surface of the target substrate;
- and
- a detection system configured to detect individual secondary electron beamlets of the secondary electron beamlet array.
Dependencies are inferred from the claim text.