A multi-beam charged particle inspection system and a method of operating a multi-beam charged particle inspection system for wafer inspection with high throughput and with high resolution and high reliability comprise a mechanism for reduction and compensation of a scanning induced aberration, such as a scanning distortion of a collective multi-beam raster scanner for beamlets propagating at an angle with respect to the optical axis of the multi-beam charged particle inspection system.

A multi-electron beam system that forms hundreds of beamlets can focus the beamlets, reduce Coulomb interaction effects, and improve resolutions of the beamlets. A Wien filter with electrostatic and magnetic deflection fields can separate the secondary electron beams from the 5 primary electron beams and can correct the astigmatism and source energy dispersion blurs for all the beamlets simultaneously.

A multiple-electron-beam-image acquisition apparatus includes an electromagnetic lens to receive and refract multiple electron beams, an aberration corrector, disposed in a magnetic field of the electromagnetic lens, to correct aberration of the multiple electron beams, an aperture-substrate, disposed movably at the upstream of the aberration corrector with respect to an advancing direction of the multiple electron beams, to selectively make an individual beam of the multiple electron beams pass therethrough independently, a movable stage to dispose thereon the aberration corrector, a stage control circuit, using an image caused by the individual beam selectively made to pass, to move the stage to align the position of the aberration corrector to the multiple electron beams having been relatively aligned with the electromagnetic lens, and a detector to detect multiple secondary electron beams emitted because the target object surface is irradiated with multiple electron beams having passed through the aberration corrector.

A charged particle beam system includes a charged particle source, a multi beam generator, an objective lens, a projection system, and a detector system. The projection system includes a first subcomponent configured to provide low frequency adjustments, and the projection system comprises a second subcomponent configured to provide a high frequency adjustments.

A multiple electron beam irradiation apparatus includes an electromagnetic lens configured to refract multiple electron beams incident, an aberration corrector arranged in the magnetic field of the electromagnetic lens and configured to be able to individually apply a bias potential and a deflection potential to each of the multiple electron beams, and an objective lens configured to focus the multiple electron beams, a trajectory of the each of which has been individually corrected by the bias potential and the deflection potential, onto a target object.

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.

A multi-beam charged particle system and a method of operating a multi-beam charged particle system can provide improved image contrast. The multi-beam charged particle system comprises a filter element or an active array element in a detection system, which can provide improved, anisotropic image contrast. The disclosure can be applied for applications of multi-beam charged particle system, where higher requirements on beam uniformity and throughput may be relevant.

A method of inspecting a specimen with an array of primary charged particle beamlets in a charged particle beam device is described. The method includes generating a primary charged particle beam with a charged particle beam emitter; illuminating a multi-aperture lens plate with the primary charged particle beam to generate the array of primary charged particle beamlets; correcting a field curvature with at least two electrodes, wherein the at least two electrodes include aperture openings; directing the primary charged particle beamlets with a lens towards an objective lens; guiding the primary charged particle beamlets through a deflector array arranged within the lens; wherein the combined action of the lens and the deflector array directs the primary charged particle beamlets through a coma free point of the objective lens; and focusing the primary charged particle beamlets on separate locations on the specimen with the objective lens.

In order to provide an aberration correction system that realizes a charged particle beam of which the anisotropy is reduced or eliminated on a sample surface even in the case where there is magnetic interference between pole stages of an aberration corrector, an correction system includes a line cross position control device (209) which controls a line cross position in the aberration corrector of the charged particle beam so that a designed value and an actually measured value of the line cross position are equal to each other, an image shift amount extraction device (210), and a feedback determination device (211) which determines whether or not changing an excitation amount of the aberration corrector is necessary whether or not changing an excitation amount is necessary from an extracted image shift amount.

An example method of imaging a specimen in a Scanning Transmission Charged Particle Microscope may include scanning a beam of charged particles across a specimen, detecting, by a segmented detector, a flux of charged particles traversing through the specimen at each scan location, for each scan location, combining detection data from different segments of the detector to produce a respective vector output, forming, based on the respective vector output data for each scan location, an imaging vector field, forming, based on the imaging vector field, an integrated vector field image, and reducing error in either the imaging vector field prior to forming the integrated vector field image or correcting the integrated vector field image, wherein the error is due to pointwise variations in beam incidence angle on the specimen.