Method of Aberration Correction and Electron Beam System

摘要

There is disclosed an electron beam system in which the third-order aberration S₃ with two-fold symmetry is corrected. If a C_s corrector is operated, parasitic aberration S₃ (third-order aberration S₃ with two-fold symmetry) is produced. A corrective third-order aberration S₃' with two-fold symmetry that cancels out the parasitic aberration S₃ is produced within a multipole element to correct the parasitic aberration S₃. The electron beam is tilted relative to the optical axis within the multipole element producing a hexapole field. The corrective third-order aberration S₃' with two-fold symmetry is introduced in each electron forming the tilted electron beam.