A method of measuring an aberration in an electron microscope includes: acquiring an image for measuring the aberration in the electron microscope; and measuring the aberration by using the image. In measuring the aberration, a direction of defocusing is specified based on a residual aberration that is uniquely determined by a configuration of an optical system of the electron microscope and an optical condition of the optical system.

An object of the present disclosure is to provide a charged particle beam apparatus that can quickly find a correction condition for a new aberration that is generated in association with beam adjustment. In order to achieve the above object, the present disclosure proposes a charged particle beam apparatus configured to include an objective lens (7) configured to focus a beam emitted from a charged particle source and irradiate a specimen, a visual field movement deflector (5 and 6) configured to deflect an arrival position of the beam with respect to the specimen, and an aberration correction unit (3 and 4) disposed between the visual field movement deflector and the charged particle source, in which the aberration correction unit is configured to suppress a change in the arrival position of the beam irradiated under different beam irradiation conditions.

One modified source-conversion unit and one method to reduce the Coulomb Effect in a multi-beam apparatus are proposed. In the modified source-conversion unit, the aberration-compensation function is carried out after the image-forming function has changed each beamlet to be on-axis locally, and therefore avoids undesired aberrations due to the beamlet tilting/shifting. A Coulomb-effect-reduction means with plural Coulomb-effect-reduction openings is placed close to the single electron source of the apparatus and therefore the electrons not in use can be cut off as early as possible.

Systems for reducing the generation of thermal magnetic field noise in optical elements of microscope systems, are disclosed. Example microscopy optical elements having reduced Johnson noise generation according to the present disclosure comprises an inner core composed of an electrically isolating material, and an outer coating composed of an electrically conductive material. The product of the thickness of the outer coating and the electrical conductivity is less than 0.01Ω.sup.−1. The outer coating causes a reduction in Johnson noise generated by the optical element of greater than 2×, 3×, or an order of magnitude or greater. In a specific example embodiment, the optical element is a corrector system having reduced Johnson noise generation. Such a corrector system comprises an outer magnetic multipole, and an inner electrostatic multipole. The inner electrostatic multipole comprises an inner core composed of an electrically isolating material and an outer coating composed of an electrically conductive material.

Disclosed among other aspects is a charged particle inspection system including a phaseplate configured and arranged to modify the local phase of charged particles in a beam to reduce the effects of lens aberrations. The phaseplate is made up of an array of apertures with the voltage and/or a degree of obscuration of the apertures being controlled individually or in groups.

A charged particle beam apparatus including a winding aberration corrector capable of correcting a chromatic aberration is provided. A multi-pole lens includes a magnetic core 150, a plurality of current lines 101 to 112, a plurality of wire-shaped electrodes 301 to 312, insulating electrode fixing portions 313 to 342 for fixing the plurality of electrodes to a structure in a vacuum container, and conductive shields 320, 321 set to a reference potential, which are provided between the electrode fixing portion and a central axis of the magnetic core, main line portions of the plurality of current lines are arranged axisymmetrically with respect to the central axis of the magnetic core along an inner wall of the magnetic core, and portions of the plurality of electrodes parallel to the central axis of the magnetic core are arranged axisymmetrically with respect to the central axis of the magnetic core.

According to one aspect of the present invention, an aberration corrector includes a first electrode substrate provided with first passage holes through which multiple electron beams pass; a second electrode substrate disposed below the first electrode substrate and provided with second passage holes through which the multiple electron beams pass, first electrodes of four or more poles being disposed individually on each top surface region of top surface regions around some second passage holes among the second passage holes; and a third electrode substrate disposed below the second electrode substrate and provided with third passage holes through which the multiple electron beams pass, second electrodes of four or more poles being disposed individually on each of top surface region of top surface regions around some third passage holes corresponding to remaining second passage holes in which the first electrodes are not disposed, among the third passage holes.

The present application relates to a method and an apparatus for determining a wavefront of a massive particle beam, including the steps of: (a) recording two or more images of a reference structure using the massive particle beam under different recording conditions; (b) generating point spread functions for the two or more recorded images with a modified reference image of the reference structure; and (c) performing a phase reconstruction of the massive particle beam on the basis of the generated point spread functions and the different recording conditions, for the purposes of determining the wavefront.

The present disclosure pertains to a beam deflection device capable of properly deflecting a beam. The present disclosure provides a beam deflection device for deflecting a beam inside a charged particle beam device, said beam deflection device being provided with: one or more electrostatic deflectors (207, 208) each having a pair of electrodes disposed so as to face each other across a beam path in a first direction orthogonal to the beam path; and one or more magnetic deflectors (209) each having a pair of magnetic poles disposed so as to face each other across the beam path in a second direction orthogonal to the beam path and to the first direction. When viewed from an incident direction of the beam, the one or more electrostatic deflectors and the one or more magnetic deflectors are stacked along the beam path such that the pair of electrodes at least partially overlap with the pair of magnetic poles and with a gap between the pair of magnetic poles.

A lens element of a charged particle system comprises an electrode having a central opening. The lens element is configured for functionally cooperating with an aperture array that is located directly adjacent said electrode, wherein the aperture array is configured for blocking part of a charged particle beam passing through the central opening of said electrode. The electrode is configured to operate at a first electric potential and the aperture array is configured to operate at a second electric potential different from the first electric potential. The electrode and the aperture array together form an aberration correcting lens.