Image Acquisition Method and Scanning Transmission Electron Microscope

A scanning transmission electron microscope comprising:

• an electron source that emits an electron beam;
• an illumination system including a condenser lens, an aperture, and an illumination system deflector that deflects the electron beam having passed through the aperture;
• a specimen stage that supports a specimen;
• an imaging apparatus configured to photograph a Ronchigram formed on a diffraction plane;
• an imaging system deflector that deflects the electron beam to be incident on the imaging apparatus;
• and
• a control unit that controls the illumination system and the imaging system deflector,
• the control unit performing processing of:
• causing the imaging system deflector to deflect the electron beam to align a center of the Ronchigram with a center of a detector plane of the imaging apparatus;
• aligning a direction of incidence of the electron beam with respect to the specimen with a crystal zone axis of the specimen by aligning a shadow of the aperture with the crystal zone axis on the diffraction plane;
• and
• causing the imaging system deflector to deflect the electron beam to align the electron beam with the center of the detector plane of the imaging apparatus.

A scanning transmission electron microscope comprising:

• an electron source that emits an electron beam;
• an illumination system for scanning a specimen with the electron beam;
• a specimen stage that supports the specimen;
• a detector that detects electrons having passed through the specimen;
• and
• a control unit that controls the illumination system,
• the control unit performing processing of scanning the specimen with the electron beam to acquire a scanned image, and
• in the processing of acquiring the scanned image, the control unit makes a direction in which scan lines are drawn orthogonal to a direction of a tilt of the specimen.