| 摘要 |
In a transmission electron microscope, an electron beam flux of a cross section constricted conically over a reference specimen is made to hit the reference specimen. The flux includes electron beams hitting the specimen at incident angles which spread conically in the direction of irradiation. The beams are focused onto a fluorescent screen at positions which are different in distance from the center according to the incident angles. A transmission image of the beam flux is gained. A Fourier transform is performed for each of inspection regions set on the transmission image. Aberration coefficients C1, C2, . . . , Ci are calculated from the obtained, Fourier-transformed images by image processing. Aberration in the imaging lenses is corrected. Consequently, the aberration can be corrected by finding the aberration coefficients C1, C2, . . . , Ci from only one transmission image. The number of transmission images or the acquisition time is reduced.
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