An improved source conversion unit of a charged particle beam apparatus is disclosed. The source conversion unit comprises a first micro-structure array including a plurality of micro-structures. The plurality of micro-structures is grouped into one or more groups. Corresponding electrodes of micro-structures in one group are electrically connected and driven by a driver to influence a corresponding group of beamlets. The micro-structures in one group may be single-pole structures or multi-pole structures. The micro-structures in one group have same or substantially same radial shifts from an optical axis of the apparatus. The micro-structures in one group have same or substantially same orientation angles with respect to their radial shift directions.

Correctors for correcting axial aberrations of a particle-optical lens in a charged particle microscope system, according to the present disclosure include a first primary multipole that generates a first primary multipole field when a first excitation is applied to the first primary multipole, and a second primary multipole that generates a second primary multipole field when a second excitation is applied to the second primary multipole. The first primary multipole is not imaged onto the second primary multipole such that a combination fourth-order aberration is created. The correctors further include a secondary multipole for correcting the fourth-order aberration and the sixth-order aberration. Such correctors may further include a tertiary multipole for correcting an eighth-order aberration.

The present invention relates to a method for examining a beam of charged particles, including the following steps: producing persistent interactions of the beam with a sample at a plurality of positions of the sample relative to the beam and deriving at least one property of the beam by analyzing the spatial distribution of the persistent interactions at the plurality of positions.

Beam intercept profiles are measured as a particle beam transversely scans across a probe. A current of beam particles, a detector intensity, or image pixel intensities can variously be measured to obtain the profiles. Multiple profiles are used to determine geometric parameters which in turn can be used to configure equipment. In one application, transverse beam intercept profiles are measured for different waist heights of the particle beam. Steepness of the several profiles can be used to determine a height of the probe as the height at which the profile is steepest. The known probe height enables placing the probe in contact with a substrate at another known height. In another application, transverse beam intercept profiles of orthogonal probe edges are used to position a beam waist, reduce spot size, or reduce astigmatism. Techniques are applicable to SEM, FIB, and nanoprobe systems. Methods and apparatus are disclosed, with variations.

A focus adjustment method for a charged particle beam device having a magnetic field lens used for focus adjustment and an astigmatism corrector includes: acquiring a plurality of first images by varying an excitation current of the magnetic field lens within a focus search range, and determining a reference value of the excitation current; removing hysteresis from the magnetic field lens by setting the excitation current of the magnetic field lens outside the focus search range before and after varying the excitation current of the magnetic field lens within the focus search range; and acquiring a plurality of second images by varying the excitation current of the magnetic field lens using the reference value as a reference and varying a stigma correction value of the astigmatism corrector at each excitation current, and then determining optimum values of the excitation current and the stigma correction value.

A method of operating a multi-beam particle beam system includes: generating a multiplicity of particle beams such that they each pass through multipole elements that are either intact or defective; focusing the particle beams in a predetermined plane; determining excitations for the deflection elements of the multipole elements; exciting the deflection elements of the multipole elements that are intact with the determined excitations; modifying the determined excitations for the deflection elements of the multipole elements that are defective; and exciting the deflection elements of the defective multipole elements with the modified excitations. Modifying the determined excitations includes adding corrective excitations to the determined excitations. The corrective excitations are the same for all deflection elements of the defective multipole element.

A charged particle assessment tool includes: an objective lens configured to project a plurality of charged particle beams onto a sample, the objective lens having a sample-facing surface defining a plurality of beam apertures through which respective ones of the charged particle beams are emitted toward the sample; and a plurality of capture electrodes adjacent respective ones of the beam apertures and configured to capture charged particles emitted from the sample.

A particle beam system includes: a particle source to generate a beam of charged particles; a first multi-lens array including a first multiplicity of individually adjustable and focusing particle lenses so that at least some of the particles pass through openings in the multi-lens array in the form of a plurality of individual particle beams; a second multi-aperture plate including a multiplicity of second openings downstream of the first multi-lens array so that some of the particles which pass the first multi-lens array impinge on the second multi-aperture plate and some of the particles which pass the first multi-lens array pass through the openings in the second multi-aperture plate; and a controller configured to supply an individually adjustable voltage to the particle lenses of the first multi-lens array and thus individually adjust the focusing of the associated particle lens for each individual particle beam.

The present disclosure aims at proposing a multi-beam irradiation device capable of correcting off-axis aberrations. In order to achieve the above object, a beam irradiation device is proposed, which includes a beam source which emits a plurality of beams; an objective lens (17) which focuses a beam on a sample; a first lens (16) which is arranged such that a lens main surface is positioned at an object point of the objective lens and deflects a plurality of incident beams toward an intersection point of a lens main surface of the objective lens and an optical axis; a second lens (15) which is arranged closer to a beam source side than the first lens and focuses the plurality of beams on a lens main surface of the first lens; and a third lens (14) which is arranged closer to the beam source side than the second lens and deflects the plurality of beams toward an intersection point of a lens main surface of the second lens and the optical axis.

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.