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.

Abstract: A multi-beam apparatus for multi-beam inspection with an improved source conversion unit providing more beamlets with high electric safety, mechanical availability and mechanical stabilization has been disclosed. The source-conversion unit comprises an image-forming element array having a plurality of image-forming elements, an aberration compensator array having a plurality of micro-compensators, and a pre-bending element array with a plurality of pre-bending micro-deflectors. In each of the arrays, adjacent elements are placed in different layers, and one element may comprise two or more sub-elements placed in different layers. The sub-elements of a micro-compensator may have different functions such as micro-lens and micro-stigmators.

Abstract: A method of detecting charged particles may include detecting beam intensity as a primary charged particle beam moves along a first direction; acquiring a secondary beam spot projection pattern as the primary charged particle beam moves along a second direction; and determining a parameter of a secondary beam spot based on the acquired secondary beam spot projection pattern. A method of compensating for beam spot changes on a detector may include acquiring a beam spot projection pattern on the detector, determining a change of the beam spot projection pattern, and adjusting a parameter of a detector cell of the detector based on the change. Another method may be provided for forming virtual apertures with respect to detector cells of a detector.

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 tilted charged-particle beam. The apparatus may comprise a first deflector located between the charged-particle source and an objective lens and configured to deflect the charged-particle beam away from the primary optical axis; a second deflector located substantially at a focal plane of the objective lens and configured to deflect the charged-particle beam back towards the primary optical axis; and a third deflector located substantially at a principal plane of the objective lens, wherein the third deflector is configured to shift a wobbling center of the objective lens to an off-axis wobbling location, and wherein the first and the second deflectors are configured to deflect the charged-particle beam to pass through the off-axis wobbling location to land on a surface of a sample at a first landing location and having a beam-tilt angle.

Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.

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 multi-beam inspection with an improved source conversion unit providing more beamlets with high electric safety, mechanical availability and mechanical stabilization has been disclosed. The source-conversion unit comprises an image-forming element array having a plurality of image-forming elements, an aberration compensator array having a plurality of micro-compensators, and a pre-bending element array with a plurality of pre-bending micro-deflectors. In each of the arrays, adjacent elements are placed in different layers, and one element may comprise two or more sub-elements placed in different layers. The sub-elements of a micro-compensator may have different functions such as micro-lens and micro-stigmators.

Abstract: A method of operating a secondary imaging system of a charged particle beam apparatus may include using an anti-scanning mode. Excitation of a component of the secondary imaging system may be adjusted synchronously with a primary scanning deflection unit. Together with an anti-scanning deflection unit performing anti-scanning, a component of the secondary imaging system, such as a lens, may be adjusted in step. As scanning and anti-scanning is performed, excitation parameters of the component may also be constantly updated.

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: 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 electrically insulating layer is configured to electrically insulate the optics elements from the first electrically conductive layer, and the second electrically conductive layer.

Abstract: A charged particle beam apparatus includes a beamlet forming unit configured to form and scan an array of beamlets on a sample. A first portion of the array of beamlets is focused onto a focus plane, and a second portion of the array of beamlets has at least one beamlet with a defocusing level with respect to the focus plane. The charged particle beam apparatus also includes a detector configured to detect an image of the sample formed by the array of beamlets, and a processor configured to estimate a level of separation between the focus plane and the sample based on the detected image and then reduce the level of separation based on the estimated level.

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: An improved charged particle beam inspection apparatus, and more particularly, a particle beam inspection apparatus including an improved alignment mechanism is disclosed. An improved charged particle beam inspection apparatus may include a second electron detection device to generate one or more images of one or more beam spots of the plurality of secondary electron beams during the alignment mode. The beam spot image may be used to determine the alignment characteristics of one or more of the plurality of secondary electron beams and adjust a configuration of a secondary electron projection system.

Abstract: The present disclosure proposes a crossover-forming deflector array of an electro-optical system for directing a plurality of electron beams onto an electron detection device. The crossover-forming deflector array includes a plurality of crossover-forming deflectors positioned at or at least near an image plane of a set of one or more electro-optical lenses of the electro-optical system, wherein each crossover-forming deflector is aligned with a corresponding electron beam of the plurality of electron beams.

Abstract: Systems and methods are provided for charged particle detection. The detection system can comprise a signal processing circuit configured to generate a set of intensity gradients based on electron intensity data received from a plurality of electron sensing elements. The detection system can further comprise a beam spot processing module configured to determine, based on the set of intensity gradients, at least one boundary of a beam spot; and determine, based on the at least one boundary, that a first set of electron sensing elements of the plurality of electron sensing elements is within the beam spot. The beam spot processing module can further be configured to determine an intensity value of the beam spot based on the electron intensity data received from the first set of electron sensing elements and also generate an image of a wafer based on the intensity value.

Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.

Abstract: A new multi-beam apparatus with a total FOV variable in size, orientation and incident angle, is proposed. The new apparatus provides more flexibility to speed the sample observation and enable more samples observable. More specifically, as a yield management tool to inspect and/or review defects on wafers/masks in semiconductor manufacturing industry, the new apparatus provide more possibilities to achieve a high throughput and detect more kinds of defects.