| 摘要 |
PURPOSE:To prevent electrification of the surface of the insulator sample by heating the sample and adjusting the acceleration voltage to a level for a secondary electron production rate of about 1 during the observation of a secondary electron image produced by irradiating the electron beam on the sample. CONSTITUTION:The accelerated electron beam discharged from an electron gun 1 is focused by a focusing lens 5 and then irradiated on an insulator sample 6. At the same time, the electron beam is scanned by a deflecting coil 8 to produce secondary electrons which are detected by a microchannel plate 9. During the above process, the surface of the sample 6 is heated by an infrared lamp 12 and the voltage for accelerating the electron beam is adjusted to a level for which the rate of production of secondary electrons by the sample 6 becomes about 1. Electrification of the insulator sample 6 is prevented due to minimal variation of the surface electric potential of the sample 6 which results from reduced resistance of the sample 6 resulting from its temperature increase. Accordingly, it is possible to perform image observation over a long time.
|
