| 摘要 |
PURPOSE:To observe a sample in the low build-up state of charges by suppressing the electric field formed by a secondary electron detector, and automatically interlocking the electric field with the work distance. CONSTITUTION:In an electron beam analyzer provided with a secondary electron detector detecting the secondary electrons emitted from a sample when an electron beam is radiated to the sample, horn-like collecting electrodes 21, 22 having flared openings and vertically divided into two are provided in front of the detection face of the secondary electron detector, and the voltage applied to the upper and collecting electrodes 21, 22 is changed interlockingly with the change of the work distance WD between an objective lens 1 and the sample. The electric field generated by the secondary electron detector can be controlled by the control of the voltage applied to the collecting electrodes 21, 22 so that no build-up of charges is generated, and the quality of the observed image is prevented from being deteriorated as the work distance is changed. The shape of the collecting electric field of secondary electrons can be changed when the voltage applied to the collecting electrodes 2, 2 is changed, thus the same control as moving the position of the secondary electron detector can be performed in response to the observation purpose.
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