Patent ID: 8866078
Filing Date: 2014-10-21
Classification: H01J

Abstract:
1. A scanning transmission electron microscope comprising: a column comprised of an electron beam source, an electron-optical system for irradiating a sample with an electron emitted from the electron beam source, in the form of an electron beam, a detector for detecting the electron beam having passed through the sample, and an aberration corrector for correcting aberrations of the electron-optical system; a control unit for controlling all the constituent elements of the column; and an information processing unit for processing a detection signal of the detector, wherein the information processing unit divides a Ronchigram acquired by the detector into a plurality of segmented areas, a feature vector reflecting both an absolute value and a direction of an off-axial defocus is worked out from an off-axial defocus found in each of the plural segmented areas, and a distance between the center of the Ronchigram and the center of the plural segmented areas.