Focused ion beam apparatus and focused ion beam irradiation method
AssigneeHitachi High-Technologies Corporation
InventorsKoichiro Takeuchi, Tohru Ishitani, Yoichi Ose
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Abstract
A focused ion beam apparatus and a focused ion beam irradiation method are disclosed. Even in the case where a magnetic field exists on the optical axis of an ion beam and the particular magnetic field undergoes a change, the ion beam is focused without separating the isotopes on the sample at the same ion beam spot position as if the magnetic field is not existent. A canceling magnetic field is generated on the optical axis of the ion beam from a canceling magnetic field generator thereby to offset the deflection of the ion beam due to the external magnetic field.
Claims28
A focused ion beam apparatus comprising:
- a scanning electron microscope having an objective lens that generates a magnetic field on a sample;
- an ion source;
- a focused ion beam optics to focus the ion beam emitted from the ion source on the sample;
- a canceling magnetic field generator to generate a canceling magnetic field on the optical axis of the ion beam;
- and
- a canceling magnetic field control unit for controlling the canceling magnetic field generated from the canceling magnetic field generator with the exciting current of the objective lens of the scanning electron microscope as an input signal thereto,
- wherein the deflection of the ion beam under the effect of a magnetic field external to the focused ion beam optics is canceled.
A focused ion beam apparats comprising:
- a scanning electron microscope having an objective lens that generates a magnetic field on a sample;
- an ion source;
- a focused ion beam optics to focus the ion beam emitted form the ion source on a sample;
- and
- a canceling magnetic field generator to generate a canceling magnetic field on the optical axis of the ion beam;
- at least one magnetic field sensor in the neighborhood of the focused ion beam optics;
- and
- a canceling magnetic field control unit for controlling the canceling magnetic field generated from the canceling magnetic field generator with the output of the magnetic field sensor as an input signal thereto,
- wherein the deflection of the ion beam under the effect of a magnetic field external to the focused ion beam optics is canceled.
A focused ion beam apparatus comprising:
- a scanning electron microscope having an objective lens that generates a magnetic field on a sample;
- an ion source;
- a focused ion beam optics to focus the ion beam emitted from the ion source on a sample;
- and
- a canceling magnetic field generator to generate a canceling magnetic field on the optical axis of the ion beam;
- wherein:
- the deflection of the ion beam under the effect of a magnetic field external to the focused ion beam optics is canceled,
- the optical axis of the scanning electron microscope and the optical axis of the ion beam cross each other at a substantially single point on the sample,
- the optical axis of the scanning electron microscope and the optical axis of the ion beam cross each other substantially at 90 degrees to each other, and
- the apparatus further comprises an electron detector arranged on the optical axis of the scanning electron microscope on the side of the crossing point far from the objective lens of the scanning electron microscope.
Dependencies are inferred from the claim text.