Electron microscope
AssigneeHitachi High-Tech Corporation
InventorsMichiko Suzuki, Yudai Kubo
Life of this patent
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Abstract
An object of the invention is to efficiently execute aberration correction in an electron microscope including an aberration corrector that corrects aberration using a multipole lens. The electron microscope according to the invention includes an aberration corrector that includes first and second multipole lenses, a transfer lens, and an adjustment lens, in which the first multipole lens is configured to correct third-order spherical aberration by adjusting a lens current, and third-order spherical aberration and fifth-order spherical aberration are collectively corrected by adjusting a transfer lens current while changing an adjustment lens current (refer to FIG. 6).
Claims10
An electron microscope that observes a sample using an electron beam, the electron microscope comprising:
- an electron optical system including an objective lens configured to scan by the electron beam;
- an aberration corrector configured to correct an aberration of a lens of the electron optical system;
- and
- a control unit configured to control the aberration corrector, wherein
- the aberration corrector includes
- first and second multipole lenses configured to generate a magnetic field for correcting a spherical aberration of the lens,
- a transfer lens configured to cause the electron beam to propagate to the objective lens, and
- an adjustment lens disposed between the transfer lens and the objective lens,
- the transfer lens is configured to correct fifth-order spherical aberration using a transfer lens current applied to the transfer lens,
- the first multipole lens is configured to correct third-order spherical aberration using a multipole lens current applied to the first multipole lens, and
- the control unit corrects the third-order spherical aberration by adjusting the transfer lens current to correct the fifth-order spherical aberration while changing an adjustment lens current applied to the adjustment lens.
Dependencies are inferred from the claim text.