| 摘要 |
PURPOSE:To measure potential distribution on a sample, even covered with dielectric on its face, by using an ion gun instead of an electron gun. CONSTITUTION:Ion beam emitted from an ion gun 21 is turned into pulse ion beam with deflecting plate 22 as well as aperture 23 and conducted through ion lens system 24 and scanning system 25 to a sample 26 for irradiation. The secondary electron volume produced by ion beam irradiation can be detected as a signal corresponding to potential distribution on the sample without being affected by charging phenomenon. Being driven by the same signal source 29, the pulse ion beam sample 26 is synchronized and during the fixed time phase within a synchronized signal, the pulse ion beam reaches the sample 26 through adjustment of a phase shifter 30. Therefore, the secondary electron signal is extracted in DC form with detector 27 to bring secondary electron image on an indicator 28, corresponding to potential distribution in specified phase of the sample. |
