Abstract: A multi-beam inspection apparatus including an adjustable beam separator is disclosed. The adjustable beam separator is configured to change a path of a secondary particle beam. The adjustable beam separator comprises a first Wien filter and a second Wien filter. Both Wien filters are aligned with a primary optical axis. The first Wien filter and the second Wien filter are independently controllable via a first excitation input and a second excitation input, respectively. The adjustable beam separator is configured move the effective bending point of the adjustable beam separator along the primary optical axis based on the first excitation input and the second excitation input.

Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit changes a single electron source into a virtual multi-source array, a primary projection imaging system projects the array to form plural probe spots on the sample, and a condenser lens adjusts the currents of the plural probe spots. In the source-conversion unit, the image-forming means is on the upstream of the beamlet-limit means, and thereby generating less scattered electrons. The image-forming means not only forms the virtual multi-source array, but also compensates the off-axis aberrations of the plurality of probe spots.

Abstract: Provided are system, method, and device for determining a classification of an image. According to embodiments, the method may include: determining, by a patch sampler model, selection probabilities of a first plurality of patches included in an image; selecting, by the patch sampler model, a second plurality of patches from among the first plurality of patches of the image based on the selection probabilities; and determining a classification of the image by processing the second plurality of patches through an encoder; wherein the patch sampler model may be trained based on a sampling loss which indicates a difference between the selection probabilities and attention scores of the image obtained via the encoder.

Abstract: The present disclosure proposes an anti-rotation lens and using it as an anti-rotation condenser lens in a multi-beam apparatus with a pre-beamlet-forming mechanism. The anti-rotation condenser lens keeps rotation angles of beamlets unchanged when changing currents thereof, and thereby enabling the pre-beamlet-forming mechanism to cut off electrons not in use as much as possible. In this way, the multi-beam apparatus can observe a sample with high resolution and high throughput, and is competent as a yield management tool to inspect and/or review defects on wafers/masks in semiconductor manufacturing industry.

Abstract: Disclosed herein is an apparatus comprising: a first electrically conductive layer, a second electrically conductive layer; a plurality of optics element s between the first electrically conductive layer and the second electrically conductive layer, wherein the plurality of optics elements are configured to influence a plurality of beams of charged particles; a third electrically conductive layer between the first electrically conductive layer and the second electrically conductive layer; and an electrically insulating layer physically connected to the optics elements, wherein the eclectically insulating layer is configured to electrically insulate the optics elements from the first electrically conductive layer, and the second electrically conductive layer.

Abstract: 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.

Abstract: Systems and methods of imaging a sample using a charged-particle beam apparatus are disclosed. The charged-particle beam apparatus may include a compound objective lens comprising a magnetic lens and an electrostatic lens, the magnetic lens comprising a cavity, and an electron detector located immediately upstream from a polepiece of the magnetic lens and inside the cavity of the magnetic lens. In some embodiments, deflectors may be located between the electron detector and the opening of the polepiece adjacent to the sample to achieve a large field of view. Electron distributions among the detectors can be manipulated without changing the landing energy by changing the potential of the control electrode(s) in the electrostatic objective lens. The electron source can be operated with several discrete potentials to cover different landing energies, while the potential difference between electron source and the extractor is fixed.

Abstract: Systems and methods of forming images of a sample using a multi-beam apparatus are disclosed. The method may include generating a plurality of secondary electron beams from a plurality of probe spots on the sample upon interaction with a plurality of primary electron beams. The method may further include adjusting an orientation of the plurality of primary electron beams interacting with the sample, directing the plurality of secondary electron beams away from the plurality of primary electron beams, compensating astigmatism aberrations of the plurality of directed secondary electron beams, focusing the plurality of directed secondary electron beams onto a focus plane, detecting the plurality of focused secondary electron beams by a charged-particle detector, and positioning a detection plane of the charged-particle detector at or close to the focus plane.

Abstract: Systems and methods of inspecting a sample using a charged-particle beam apparatus with enhanced probe current and high current density of the primary charged-particle beam are disclosed. The apparatus includes a charged-particle source, a first condenser lens configured to condense the primary charged-particle beam and operable in a first mode and a second mode, wherein: in the first mode, the first condenser lens is configured to condense the primary charged-particle beam, and in the second mode, the first condenser lens is configured to condense the primary charged-particle beam sufficiently to form a crossover along the primary optical axis. The apparatus further includes a second condenser lens configured to adjust a first beam current of the primary charged-particle beam in the first mode and adjust a second beam current of the primary charged-particle beam in the second mode, the second beam current being larger than the first beam current.

Abstract: Systems and methods of providing a probe spot in multiple modes of operation of a charged-particle beam apparatus are disclosed. The method may comprise activating a charged-particle source to generate a primary charged-particle beam and selecting between a first mode and a second mode of operation of the charged-particle beam apparatus. In the flooding mode, the condenser lens may focus at least a first portion of the primary charged-particle beam passing through an aperture of the aperture plate to form a second portion of the primary charged-particle beam, and substantially all of the second portion is used to flood a surface of a sample. In the inspection mode, the condenser lens may focus a first portion of the primary charged-particle beam such that the aperture of the aperture plate blocks off peripheral charged-particles to form the second portion of the primary charged-particle beam used to inspect the sample surface.

Abstract: Disclosed herein is an apparatus comprising: a source of charged particles configured to emit a beam of charged particles along a primary beam axis of the apparatus; a condenser lens configured to cause the beam to concentrate around the primary beam axis; an aperture; a first multi-pole lens; a second multi-pole lens; wherein the first multi-pole lens is downstream with respect to the condenser lens and upstream with respect to the second multi-pole lens; wherein the second multi-pole lens is downstream with respect to the first multi-pole lens and upstream with respect to the aperture.

Abstract: An improved method of wafer inspection is disclosed. The improved method includes a non-transitory computer-readable medium storing a set of instructions that are executable by at least one processor of a device to cause the device to perform a method comprising: placing the wafer at a location on a stage; moving one or more movable segments of a conductive ring inward in a radial direction to enable the conductive ring to be within a predetermined distance from an edge of the wafer; and adjusting a voltage applied to the conductive ring or to a voltage applied to the wafer so that to enable the voltage applied to the conductive ring to be substantially equal to the voltage applied to the wafer to provide a substantially consistent electric field across an inner portion of the conductive ring and an outer portion of the wafer.

Abstract: Systems and methods of enhancing imaging resolution by reducing crosstalk between detection elements of a secondary charged-particle detector in a multi-beam apparatus are disclosed. The multi-beam apparatus may comprise an electro-optical system comprising a beam-limit aperture plate having a surface substantially perpendicular to an optical axis, the beam-limit aperture plate comprising a first aperture at a first distance relative to the surface of the beam-limit aperture plate, and a second aperture at a second distance relative to the surface of the beam-limit aperture plate, the second distance being different from the first distance. The first aperture may be a part of a first set of apertures of the beam-limit aperture plate at the first distance, and the second aperture may be a part of a second set of apertures of the beam-limit aperture plate at the second distance.

Abstract: A multi-beam inspection apparatus including an improved source conversion unit is disclosed. The improved source conversion unit may comprise a micro-structure deflector array including a plurality of multipole structures. The micro-deflector deflector array may comprise a first multipole structure having a first radial shift from a central axis of the array and a second multipole structure having a second radial shift from the central axis of the array. The first radial shift is larger than the second radial shift, and the first multipole structure comprises a greater number of pole electrodes than the second multipole structure to reduce deflection aberrations when the plurality of multipole structures deflects a plurality of charged particle beams.

Abstract: Systems and methods of imaging a sample using a charged-particle beam apparatus are disclosed. The charged-particle beam apparatus may include a compound objective lens comprising a magnetic lens and an electrostatic lens, the magnetic lens comprising a cavity, and an electron detector located immediately upstream from a polepiece of the magnetic lens and inside the cavity of the magnetic lens. In some embodiments, deflectors may be located between the electron detector and the opening of the polepiece adjacent to the sample to achieve a large field of view. Electron distributions among the detectors can be manipulated without changing the landing energy by changing the potential of the control electrode(s) in the electrostatic objective lens. The electron source can be operated with several discrete potentials to cover different landing energies, while the potential difference between electron source and the extractor is fixed.

Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit changes a single electron source into a virtual multi-source array, a primary projection imaging system projects the array to form plural probe spots on the sample, and a condenser lens adjusts the currents of the plural probe spots. In the source-conversion unit, the image-forming means is on the upstream of the beamlet-limit means, and thereby generating less scattered electrons. The image-forming means not only forms the virtual multi-source array, but also compensates the off-axis aberrations of the plurality of probe spots.

Abstract: Systems and methods for observing a sample in a multi-beam apparatus are disclosed. A charged particle optical system may include a deflector configured to form a virtual image of a charged particle source and a transfer lens configured to form a real image of the charged particle source on an image plane. The image plane may be formed at least near a beam separator that is configured to separate primary charged particles generated by the source and secondary charged particles generated by interaction of the primary charged particles with a sample. The image plane may be formed at a deflection plane of the beam separator. The multi-beam apparatus may include a charged-particle dispersion compensator to compensate dispersion of the beam separator. The image plane may be formed closer to the transfer lens than the beam separator, between the transfer lens and the charged-particle dispersion compensator.

Abstract: Systems and methods of enhancing imaging resolution by reducing crosstalk between detection elements of a secondary charged-particle detector in a multi-beam apparatus are disclosed. The multi-beam apparatus may comprise an electro-optical system for projecting a plurality of secondary charged-particle beams from a sample onto a charged-particle detector. The electro-optical system may include a first pre-limit aperture plate comprising a first aperture configured to block peripheral charged-particles of the plurality of secondary charged-particle beams, and a beam-limit aperture array comprising a second aperture configured to trim the plurality of secondary charged-particle beams. The charged-particle detector may include a plurality of detection elements, wherein a detection element of the plurality of detection elements is associated with a corresponding trimmed beam of the plurality of secondary charged-particle beams.

Abstract: Systems and methods of mitigating Coulomb effect in a multi-beam apparatus are disclosed. The multi-beam apparatus may include a charged-particle source configured to generate a primary charged-particle beam along a primary optical axis, a first aperture array comprising a first plurality of apertures having shapes and configured to generate a plurality of primary beamlets derived from the primary charged-particle beam, a condenser lens comprising a plane adjustable along the primary optical axis, and a second aperture array comprising a second plurality of apertures configured to generate probing beamlets corresponding to the plurality of beamlets, wherein each of the plurality of probing beamlets comprises a portion of charged particles of a corresponding primary beamlet based on at least a position of the plane of the condenser lens and a characteristic of the second aperture array.

Abstract: 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.