| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the S/N (signal-to-noise ratio) of detected images and to enable the obtaining of homogeneous and clear images by constituting a telecentric electro-optic system out of an objective electro-optical system and a beam limiting means. SOLUTION: An irradiating means 11 irradiates a sample with electron beams, and the surface of the sample is irradiated with electron beams via a deflecting means 3, a beam limiting means 5, and an objective electro-optical system 4. When the surface of the sample is irradiated with electron beams, secondary electrons, reflected electrons, or back scattering electrons are generated as secondary beams from the surface of the sample irradiated with beams. The secondary beams are detected by an electron detecting means 2 via the objective electro-optical system 4 and the deflecting means 3. At this time, the limiting means 5 is arranged at the focus location of the objective electro-optical system 4, and the objective electro-optical system and the limiting means 5 constitute a telecentric electro-optical system. Therefore, the main rays of the secondary beams from the sample forms a crossover at the focus location of the objective electro-optical system 4, and all of them are detected by the electron detecting means 2.</p> |
