| 摘要 |
PURPOSE: A multiple pole lens for an electronic column is provided to facilitate manufacture by facing a slit or aperture each other. CONSTITUTION: A quadruple pole lens(400) includes two electrode layers at a right angle to a Z-axis. Electrode layers(400a,400b) comprise a slit based on the center axis through which an electronic beam passes. An electrode layer is arranged on the electronic optical axis to alternatively position silts. Different voltages are applied to the electrode layer. The width of the slit(430,440) is wider than the size of the aperture. |
