An apparatus comprising a set of pixels configured to shape a beamlet approaching the set of pixels and a set of pixel control members respectively associated with each of the set of pixels, each pixel control member being arranged and configured to apply a signal to the associated pixel for shaping the beamlet.

The disclosure relates to apparatus and methods for manipulating charged particle beams. In one arrangement, an aperture assembly is provided that comprises a first aperture body and a second aperture body. Apertures in the first aperture body are aligned with apertures in the second aperture body. The alignment allows charged particle beams to pass through the aperture assembly. The first aperture body comprises a first electrode system for applying an electrical potential to an aperture perimeter surface of each aperture in the first aperture body. The first electrode system comprises a plurality of electrodes. Each electrode is electrically isolated from each other electrode and electrically connected simultaneously to the aperture perimeter surfaces of a different one of a plurality of groups of the apertures in the first aperture body.

The disclosure relates to charged-particle multi-beam columns and multi-beam column arrays. In one arrangement, a sub-beam defining aperture array forms sub-beams from a beam of charged particles. A collimator array collimates the sub-beams An objective lens array projects the collimated sub-beams onto a sample. A detector detects charged particles emitted from the sample. Each collimator is directly adjacent to one of the objective lenses. The detector is provided in a plane down-beam from the sub-beam defining aperture array.

A scanning electron microscope device for a sample to be detected and an electron beam inspection apparatus are provided, the scanning electron microscope device being configured to project electron beam to a surface of the sample to generate backscattered electrons and secondary electrons, and comprising: an electron beam source, a deflection mechanism, and an objective lens assembly. The deflection mechanism comprises a first deflector located downstream the electron beam source and a second deflector located downstream the first deflector. The objective lens assembly comprises: an excitation coil; and a magnetic yoke, formed by a magnetizer material as a housing which opens towards the sample and comprising a hollow body defining an internal chamber where the excitation coil is accommodated, and at least one inclined portion extending inward from the hollow body at an angle with reference to the hollow body and directing towards the optical axis, with an end of the at least one inclined portion being formed into a pole piece. The deflection mechanism further comprises a third deflector located between the second deflector and the objective lens assembly and disposed in an opening delimited and circumscribed by the pole piece, and each of the first deflector, the second deflector and the third deflector is an electrostatic deflector.

A scanning electron microscope device for a sample to be detected and an electron beam inspection apparatus are provided, the scanning electron microscope device being configured to project electron beam to a surface of the sample to generate backscattered electrons and secondary electrons, and comprising: an electron beam source, a deflection mechanism, and an objective lens assembly. The deflection mechanism comprises a first deflector located downstream the electron beam source and a second deflector located downstream the first deflector. The objective lens assembly comprises: an excitation coil; and a magnetic yoke, formed by a magnetizer material as a housing which opens towards the sample and comprising a hollow body defining an internal chamber where the excitation coil is accommodated, and at least one inclined portion extending nward from the hollow body at an angle with reference to the hollow body and directing towards the optical axis, with an end of the at least one inclined portion being formed into a pole piece. The deflection mechanism further comprises a compensation electrode, which is located between the pole piece and the surface of the sample and is configured to adjust a focusing position of the electron beam at which the electron beam is focused, in a condition of excitation thereof with a voltage being applied thereon, by adjusting the voltage.

A method of reducing aberration comprises separating charged particles of a beam based on energy of the charged particles to form beamlets, each of the beamlets configured to include charged particles at a central energy level; and deflecting the beamlets so that beamlets having different central energy levels are deflected differently. An aberration corrector comprises a dispersive element configured to cause constituent parts of a beam (e.g. a charged particle beam) to spread apart based on energy; an aperture array configured to form beamlets from the spread apart beam; and a deflector array configured to deflect the beamlets differently based on central energy levels of particles that form the beamlets.

Prior to execution of primary correction, a first centering process, an in-advance correction of a particular aberration, and a second centering process are executed stepwise. In the first centering process and the second centering process, a ronchigram center is identified based on a ronchigram variation image, and is matched with an imaging center. In the in-advance correction and the post correction of the particular aberration, a particular aberration value is estimated based on a ronchigram, and the particular aberration is corrected based on the particular aberration value.

A method for electron microscopy comprises: adjusting at least one of an electron beam and an image beam in such a way that off-axial aberrations inflicted on at least one of the electron beam and the image beam are minimized, the adjusting performed by using a beam adjusting component to obtain at least one modified image beam, wherein the adjusting comprises applying both shifting and tilting to at least one of the electron beam and the image beam and wherein the amount of tilting of at least one of the electron beam and the image beam depends on the amount of shifting of at least one of the electron beam and the image beam respectively and wherein the amount of tilting is computed based on at least one of coma and astigmatism introduced as a consequence of the shift.

Electrostatic mirror chromatic aberration (Cc) correctors, according to the present disclosure, comprise an electrostatic electron mirror that itself comprises a multipole. The electrostatic electron mirror is positioned within the corrector such that, when the corrector is in use, an electron beam passing through the corrector is not incident on the electrostatic electron mirror along the optical axis of the mirror. The mirror object distance of the electrostatic mirror is equal to the mirror image distance of the electrostatic mirror, and the electrostatic mirror is configured such that the electrostatic mirror applies no dispersion or coma aberration to the electron beam. The multipole is positioned in the mirror plane of the electrostatic electron mirror, and in some embodiments the multipole is a quadrupole.

A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit forms plural and parallel images of one single electron source by deflecting plural beamlets of a parallel primary-electron beam therefrom, and one objective lens focuses the plural deflected beamlets onto a sample surface and forms plural probe spots thereon. A movable condenser lens is used to collimate the primary-electron beam and vary the currents of the plural probe spots, a pre-beamlet-forming means weakens the Coulomb effect of the primary-electron beam, and the source-conversion unit minimizes the sizes of the plural probe spots by minimizing and compensating the off-axis aberrations of the objective lens and condenser lens.