Electron source with magnetic suppressor electrode
AssigneeKLA Corporation
InventorsNikolai Chubun, Xinrong Jiang, Youfei Jiang, Christopher Sears
Life of this patent
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Abstract
An electron source is disclosed. The electron source may include an electron emitter configured to generate one or more electron beams. The electron source may further include a magnetic suppressor electrode surrounding at least a portion of the electron emitter. The magnetic suppressor electrode may be formed from one or more magnetic materials. The magnetic suppressor may be configured to shield at least a portion of the electron emitter from an axial magnetic field. The electron source may further include an extractor electrode positioned adjacent to a tip of the electron emitter.
Claims12
An electron source, comprising:
- an electron emitter configured to generate one or more electron beams;
- a stand-alone magnetic suppressor electrode surrounding at least a portion of the electron emitter, wherein the magnetic suppressor electrode is formed from one or more magnetic materials, wherein the magnetic suppressor electrode includes a conical section that surrounds the electron emitter, wherein the magnetic suppressor electrode is configured to shield the shaft of the tip of electron emitter from the axial magnetic field from a magnetic lens thereby mitigating drift of the electron emitter;
- and
- an extractor electrode positioned adjacent to a tip of the electron emitter.
An electron beam inspection system, comprising:
- an electron source comprising:
- an electron emitter configured to generate one or more electron beams;
- a stand-alone magnetic suppressor electrode surrounding at least a portion of the electron emitter, wherein the magnetic suppressor electrode is formed from one or more magnetic materials, wherein the magnetic suppressor electrode includes a conical section that surrounds the electron emitter, wherein the magnetic suppressor electrode is configured to shield the shaft of the tip of electron emitter from the axial magnetic field from a magnetic lens thereby mitigating drift of the electron emitter;
- and
- an extractor electrode positioned adjacent to a tip of the electron emitter;
- an electron-optical column including a set of electron-optical elements configured to direct the electron beam onto a sample, the set of electron-optical elements including at least the magnetic lens.
A method, comprising:
- emitting a particle beam from a tip of an electron emitter, wherein the electron emitter is at least partially surrounded by a stand-alone magnetic suppressor electrode, wherein the magnetic suppressor electrode includes a conical section that surrounds the electron emitter;
- and
- shielding a shaft of a tip of the electron emitter from an axial magnetic field from a magnetic lens thereby mitigating drift of the electron emitter;
- and
- compressing a magnetic field of the magnetic lens toward the electron emitter to reduce the working distance of the magnetic lens below 10 mm to correct spherical and chromatic aberrations and limit EMI-induced vibration of the emitter.
Dependencies are inferred from the claim text.