US 12,518,944 B2Granted

Electron microscope and image acquisition method

AssigneeJEOL Ltd.

InventorsKazunori Somehara, Yuji Kohno

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Abstract

An electron microscope includes an electron source for emitting an electron beam, an illumination lens for focusing the beam, an aberration corrector for correcting aberrations, an illumination deflector assembly disposed between the illumination lens and the aberration corrector and operating to deflect the beam and to vary its tilt relative to a sample, a scanning deflector for scanning the sample with the beam, an objective lens, a detector for detecting electrons transmitted through the sample and producing an image signal, a control section for controlling the illumination deflector assembly, and an image generating section for receiving the image signal and generating a differential phase contrast (DPC) image. The tilt of the beam is varied by the illumination deflector assembly such that the image generating section generates a plurality of DPC images at different tilt angles of the beam and creates a final image based on the DPC images.

Claims12

Dependent claims

An electron microscope comprising:

an electron source for emitting an electron beam;
an illumination lens for focusing the emitted electron beam;
an aberration corrector for correcting aberrations;
an illumination deflector assembly disposed ahead of the aberration corrector and operating to deflect the electron beam and to vary a tilt of the electron beam relative to a sample;
a scanning deflector for scanning the sample with the electron beam;
an objective lens;
a detector for detecting electrons transmitted through the sample and producing an image signal;
a control section for controlling the illumination deflector assembly;
and
an image generating section for receiving the image signal and generating a differential phase contrast (DPC) image,
wherein the tilt of the electron beam is varied by the illumination deflector assembly such that the image generating section generates a plurality of DPC images at a plurality of different tilt angles of the electron beam and creates a final image by averaging the plurality of DPC images,
wherein said illumination deflector assembly comprises:
a first deflector disposed at a first stage and operating to deflect the electron beam along a first axis;
a second deflector disposed at the first stage and operating to deflect the electron beam along a second axis intersecting the first axis;
a third deflector disposed at a second stage and operating to deflect the electron beam along the first axis;
and
a fourth deflector disposed at the second stage and operating to deflect the electron beam along the second axis;
wherein, when the first deflector is made to deflect the electron beam along the first axis, the control section corrects, by the use of the third and fourth deflectors, positional deviation of the electron beam on the sample caused by the deflection of the electron beam provided by the first deflector.

15 more elements

An electron microscope comprising:

an electron source for emitting an electron beam;
an illumination lens for focusing the emitted electron beam;
an aberration corrector for correcting aberrations;
an illumination deflector assembly disposed ahead of the aberration corrector and operating to deflect the electron beam and to vary a tilt of the electron beam relative to a sample;
a scanning deflector for scanning the sample with the electron beam;
an objective lens;
a detector for detecting electrons transmitted through the sample and producing an image signal;
a control section for controlling the illumination deflector assembly;
and
an image generating section for receiving the image signal and generating a differential phase contrast (DPC) image,
wherein the tilt of the electron beam is varied by the illumination deflector assembly such that the image generating section generates a plurality of DPC images at a plurality of different tilt angles of the electron beam and creates a final image by averaging the plurality of DPC images, and
wherein said control section causes said illumination deflector assembly to vary said tilt when said image generating section is not acquiring said image signal.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/973,993Filed 26 Oct 2022
Priority: JP 2021-17558027 Oct 2021
Published: US 2023/0127255 A127 Apr 2023
Granted: 6 Jan 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H01J 37/1478
Arrangements for directing or deflecting the discharge along a desired path: beam tilting means, i.e. for stereoscopy or for beam channelling
H01J 37/10
Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical…: lenses
H01J 37/153
Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical…:…
H01J 37/263
Details: contrast, resolution or power of penetration