Patent ID: 8592776
Filing Date: 2013-11-26
Classification: H01J

Abstract:
1. A charged particle beam apparatus comprising: a charged particle source; a stage for supporting a specimen; a beam separator; an electrostatic mirror disposed in a path of charged particles emitted from the charged particle source, between the charged particle source and the stage; and an aberration corrector disposed between the beam separator and the electrostatic mirror, in a section of the path of the charged particles between the charged particle source and the electrostatic mirror, and a section of the path of the charged particles between the electrostatic mirror and the stage, for use in common with both of those sections of the path; wherein a field where the aberration corrector is formed is made up of magnetic quadrupole fields in combination with electrostatic octupole fields for correction of off-axial aberration, and wherein the magnetic quadrupole fields are symmetric with respect to a symmetry plane and the electrostatic octupole fields are antisymmetric with respect to the symmetry plane.