| 摘要 |
A retarding field scanning electron microscope is described. The microscope includes a scanning deflection assembly configured for scanning an electron beam over a specimen, one or more controllers in communication with the scanning deflection assembly for controlling the electron beam scanning pattern, and a combined magnetic-electrostatic objective lens configured for focusing the electron beam including an electrostatic lens portion. The electrostatic lens portion includes a first electrode with a high potential bias, and a second electrode disposed between the first electrode and the specimen plane with a potential bias lower than the first electrode, wherein the second electrode is configured for providing a retarding field. The microscope further includes a voltage supply connected to the second electrode for biasing the second electrode and being in communication with the controllers, wherein the controllers synchronize a variation of the potential of the second electrode with the scanning pattern.
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