| 摘要 |
PURPOSE:To improve the resolving power by composing the unit applying a voltage to a cylindrical object electrode furnished within the magnetic pole of an object lens in order to lead the secondary electrons to a detector furnished at the electron source side of the object lens, and applying a voltage to the electrode of the detector in order to lead the secondary electrons to the detecting surface of the detector. CONSTITUTION:The secondary electrons 4 and 4' emitted from a sample 3 pass through almost the center of an object lens 2 by the magnetic field produced by the object lens 2 and the static electric field produced by an object electrode 8, and strike a detector 5 at the position where the magnetic field is weakened, being captured there by the detector 5. In this case, a specific negative voltage is applied to a cylindrical detector electrode 7 furnished at the center of the detector 5, and the secondary electrons 4 and 4' are set to be injected to the detecting surface of the detector 5. In such a composition, the capturing rate of the secondary electrons 4 and 4' can be improved, and the resolving power can be increased.
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