Abstract: 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.

Abstract: A multi-beam electron-optical system for a charged-particle assessment tool, the system comprising: a plurality of control lenses, a plurality of objective lenses and a controller. The plurality of control lenses are configured to control a parameter of a respective sub-beam. The plurality of objective lenses are configured to project one of the plurality of charged-particle beams onto a sample. The controller controls the control lenses and the objective lenses so that the charged particles are incident on the sample with a desired landing energy, demagnification and/or beam opening angle.

Abstract: The disclosure relates to an electron-optical module of an electron-optical apparatus. The electron-optical module comprises a vacuum chamber, a high voltage shielding arrangement located within the vacuum chamber, and an aperture array configured to form a plurality of beamlets from an electron beam and located within the high voltage shielding arrangement. Wherein the electron-optical module can be configured to be removable from the electron-optical apparatus.

Abstract: Electron-optical devices and associated methods are disclosed. In one arrangement, an electron-optical device projects a multi-beam of sub-beams of charged particles to a sample. A plurality of plates are provided in which are defined respective aperture arrays. The plates comprise an objective lens array configured to project the sub-beams towards the sample. The aperture arrays defined in at least two of the plates each have a geometrical characteristic configured to apply a perturbation to a corresponding target property of the sub-beams. A controller controls potentials applied to the plates having the geometrical characteristics such that the applied perturbations together substantially compensate for a variation in the target property over a range of a parameter of the device.

Abstract: A charged-particle tool including: a condenser lens array configured to separate a beam of charged particles into a first plurality of sub-beams along a respective beam path and to focus each of the sub-beams to a respective intermediate focus; an array of objective lenses, each objective lens configured to project one of the plurality of sub-beams onto a sample; a corrector including an array of elongate electrodes, the elongate electrodes extending substantially perpendicular to the beam paths of the first plurality of sub-beams and arranged such that a second plurality of the sub-beams propagate between a pair of the elongate electrodes, the second plurality of sub-beams being a subset of the first plurality of sub-beams; and an electric power supply configured to apply a potential difference between the pair of elongate electrodes so as to deflect the second plurality of sub-beams by a desired amount.

Abstract: Charged particle assessment tools and inspection methods are disclosed. In one arrangement, a condenser lens array divides a beam of charged particles into a plurality of sub-beams. Each sub-beam is focused to a respective intermediate focus. Objective lenses downstream from the intermediate foci project sub-beams from the condenser lens array onto a sample. A path of each sub-beam is substantially a straight line from each condenser lens to a corresponding objective lens.

Abstract: A multi-beam manipulator device operates on sub-beams of a multi-beam to deflect the sub-beam paths. The device include: an electrode as pairs of parallel surfaces. Each pair of parallel surfaces includes a first surface that is arranged along a side of a corresponding line of sub-beam paths and a second surface that is arranged parallel to the first surface and along an opposite side of the corresponding line of sub-beam paths. A first pair of parallel surfaces is configured to electrostatically interact with an entire line of sub-beams in the multi-beam so that it is capable of applying a deflection amount to the paths of sub-beams in a first direction. A second pair of parallel surfaces is configured to electro-statically interact with an entire line of sub-beams in the multi-beam so that it is capable of applying another deflection amount to the paths of sub-beams in a second direction.

Abstract: A charged particle assessment tool including: 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, each capture electrode adjacent a respective one of the beam apertures, configured to capture charged particles emitted from the sample.

Abstract: A method for making a semiconductor memory device comprising a plurality of memory cells for storing one or more data values, the method comprising; exposing a pattern on a wafer for creating structures for a plurality of memory cells for the semiconductor memory device, wherein the pattern is exposed by means of one or more charged particle beams; and varying an exposure dose of the one or more charged particle beams during exposure of the pattern to generate a set of one or more non-common features in one or more structures of at least one of the memory cells, so that the structures of the at least one memory cell differ from the corresponding structures of other memory cells of the semiconductor memory device.

Abstract: An improved methods and systems for detecting defect(s) on a mask are disclosed. An improved method comprises inspecting an exposed wafer after the wafer was exposed, by a lithography system using a mask, with a selected process condition that is determined based on a mask defect printability under the selected process condition; and identifying, based on the inspection, a wafer defect that is caused by a defect on the mask to enable identification of the defect on the mask.

Abstract: 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.

Abstract: A data processing device for detecting defects in sample image data generated by a charged particle assessment system, the device comprising: a first processing module configured to receive a sample image datastream from the charged particle assessment system, the sample image datastream comprising an ordered series of data points representing an image of the sample, and to apply a first defect detection test to select a subset of the sample image datastream as first selected data, wherein the first defect detection test is a localised test which is performed in parallel with receipt of the sample image datastream; and a second processing module configured to receive the first selected data and to apply a second defect detection test to select a subset of the first selected data as second selected data.

Abstract: A multi-source illumination apparatus for illuminating a sample with charged particles, wherein beams, from a plurality of sources, are arranged such that a beam from at least one source intersects, at a plane of a condenser lens, with at least part of one other beam from a different one of the plurality of sources. The condenser lens is configured to separately collimate the received beams from each source. A manipulator array arrangement is configured to manipulate the collimated beams to generate one or more beams, in a single column, that include charged particles from the plurality of sources. The manipulator array arrangement includes a multi-beam generator configured to receive the plurality of substantially parallel substantially collimated beams generated by the deflector array, and generate a multibeam in dependence on the received plurality of substantially parallel substantially collimated beams, wherein the multi-beam includes a plurality of substantially collimated sub-beams.

Abstract: A charged-particle assessment tool comprising: a condenser lens array, a collimator, a plurality of objective lenses and an electric power source. The condenser lens array configured to divide a beam of charged particles into a plurality of sub-beams and to focus each of the sub-beams to a respective intermediate focus. The collimator being at each intermediate focus and configured to deflect a respective sub-beam so that it is incident on the sample substantially normally. The plurality of objective lenses, each configured to project one of the plurality of charged-particle beams onto a sample. Each objective lens comprises: a first electrode; and a second electrode that is between the first electrode and the sample. The electric power source configured to apply first and second potentials to the first and second electrodes respectively such that the respective charged-particle beam is decelerated to be incident on the sample with a desired landing energy.

Abstract: A charged-particle assessment tool comprising a plurality of beam columns. Each beam column comprises: a charged-particle beam source configured to emit charged particles; a plurality of condenser lenses configured to form charged particles emitted from the charged-particle beam source into a plurality of charged-particle beams; and a plurality of objective lenses, each configured to project one of the plurality of charged-particle beams onto a sample. The beam columns are arranged adjacent one-another so as to project the charged particle beams onto adjacent regions of the sample.

Abstract: Disclosed herein is an electron-optical assembly testing system for testing an electron-optical assembly, the system comprising: a source of charged particles configured to emit a beam of charged particles; an electron-optical assembly holder configured to hold an electron-optical assembly to be tested such that, when the system is in use with an electron-optical assembly held by the electron-optical assembly holder, the electron-optical assembly is illuminated by the beam; and a sub-beam detector for detecting sub-beams of charged particles that have been transmitted through the electron-optical assembly.

Abstract: A method for making a semiconductor memory device comprising a plurality of memory cells for storing one or more data values, the method comprising: exposing a pattern on a wafer for creating structures for a plurality of memory cells for the semiconductor memory device, wherein the pattern is exposed by means of one or more charged particle beams; and varying an exposure dose of the one or more charged particle beams during exposure of the pattern to generate a set of one or more non-common features in one or more structures of at least one of the memory cells, so that the structures of the at least one memory cell differ from the corresponding structures of other memory cells of the semiconductor memory device.

Abstract: 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 5 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.

Abstract: The embodiments of the present disclosure provide various techniques for detecting backscatter charged particles, including accelerating charged particle sub-beams along sub-beam paths to a sample, repelling secondary charged particles from detector arrays, and providing devices and detectors which can switch between modes for primarily detecting charged particles and modes for primarily detecting secondary particles.

Abstract: 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.