Aberration measurement method and electron microscope
AssigneeJEOL Ltd.
InventorsYuji Kohno, Akiho Nakamura
Life of this patent
Estimating the term…
Abstract
An aberration measurement method for an objective lens in an electron microscope including an objective lens which focuses an electron beam that illuminates a specimen, and a detector which detects an electron beam having passed through the specimen, includes: introducing a coma aberration to the objective lens; measuring an aberration of the objective lens before introducing the coma aberration to the objective lens; measuring an aberration of the objective lens after introducing the coma aberration to the objective lens; and obtaining a position of an optical axis of the objective lens on a detector plane of the detector based on measurement results of the aberration of the objective lens before and after introducing the coma aberration.
Claims13
An aberration measurement method for an objective lens in an electron microscope comprising an objective lens which focuses an electron beam that illuminates a specimen, and a detector which detects an electron beam having passed through the specimen, the aberration measurement method comprising:
- introducing a coma aberration to the objective lens;
- measuring an aberration of the objective lens before introducing the coma aberration to the objective lens;
- measuring an aberration of the objective lens after introducing the coma aberration to the objective lens;
- and
- obtaining a position of an optical axis of the objective lens on a detector plane of the detector based on measurement results of the aberration of the objective lens before and after introducing the coma aberration.
An electron microscope comprising:
- an objective lens which focuses an electron beam that illuminates a specimen;
- a detector which detects an electron beam having passed through the specimen;
- and
- an aberration measuring unit which measures an aberration of the objective lens,
- the aberration measuring unit performing a process of obtaining a position of an optical axis of the objective lens on a detector plane of the detector based on measurement results of an aberration before and after introducing a coma aberration to the objective lens.
Dependencies are inferred from the claim text.