| 摘要 |
PURPOSE:To image an electron probe of minute diameter without performing any complicate control or operation by locating the final stage lens of four focusing lenses near a front objective and adjusting the synthetic reduction rate to below a given level. CONSTITUTION:Four focusing lenses (C1-C4) are installed between an electron ray source and a front objective (L1). The final stage lens (C4) is placed immediately in front of the front objective (L1). The synthetic reduction rate is adjusted to be 1/30 or lower. The diameter of an image (P1) located 130mm. apart from the lens (C1) is 1,000nm which is then reduced with the lens (C2) into 40nm that is the diameter of an image (P2). Following that, the image (P2) passes through the lens (C3) without being reduced in the size to produce an image (P3) which is then reduced into 1/20 by means of the lenses (C4) and (L1), thereby imaging an electron probe of 2nm diameter on a sample (Q). Therefore, when the electron probe is not accurately imaged on the sample (Q), controlling can be performed only by changing the focal distance of the third stage focusing lens (C3). Accordingly it is possible to perform rapid operation of an irradiation system for an electron ray device. |
