| 摘要 |
<p>There is disclosed an electron beam system in which the third-order aberration S 3 with two-fold symmetry is corrected. If a C s corrector (17) is operated, parasitic aberration S 3 (third-order aberration S 3 with two-fold symmetry) is produced. A corrective third-order aberration S 3 ' with two-fold symmetry that cancels out the parasitic aberration S 3 is produced within a multipole element (3,7) to correct the parasitic aberration S 3 . The electron beam (EB) is tilted relative to the optical axis (O) within the multipole element (3 or 7). The corrective third-order aberration S 3 ' with two-fold symmetry is introduced in each electron forming the tilted electron beam.</p> |
