| 摘要 |
PURPOSE:To erase a voltage image under a surface layer and fetch only a superficial voltage image by providing a flat gun, which can irradiate an electron beam scanning area by a uniform electron shower, to a position in the upper as viewed from a sample and not disturbing scanning of an electron beam. CONSTITUTION:A sample chamber 7 is provided to the bottom part of an electron optical mirror cylinder 6 consisting of an electron gun 1, blanker 2, focusing lens 3, X-Y deflecting coil 4 and an objective lens 5. A flag gun 9 is provided to a position in the upper of a sample 8 in the chamber 7 and not disturbing scanning of an electron beam generated from the mirror cylinder 6, and the gun 9 is controlled by a controller 10. An X-Y stage 11 is provided in the sample chamber 7, and a secondary electron detector 12 is provided appearing to the sample 8. The detector 12 is connected to an image fetch display device 14. In this way, prior to scanning of the sample 8 by an electron beam, a uniform electron shower by the gun 9 is applied to the sample, and an influence of a voltage image under a surface layer is eliminated, then only the superficial voltage image can be fetched. |
