A multiple electron beam irradiation apparatus includes a forming mechanism which forms multiple primary electron beams; a plurality of electrode substrates being stacked in each of which a plurality of openings of various diameter dimensions are formed, the plurality of openings being arranged at passage positions of the multiple primary electron beams, and through each of which a corresponding one of the multiple primary electron beams passes, the plurality of electrode substrates being able to adjust an image plane conjugate position of each of the multiple primary electron beams depending on a corresponding one of the various diameter dimensions; and a stage which is capable of mounting thereon a target object to be irradiated with the multiple primary electron beams having passed through the plurality of electrode substrates.

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.

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.

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.

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.

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.

A multi-column scanning electron microscopy (SEM) system includes a column assembly, where the column assembly includes a first substrate array assembly and at least a second substrate array assembly. The system also includes a source assembly, the source assembly including two or more illumination sources configured to generate two or more electron beams and two or more sets of a plurality of positioners configured to adjust a position of a particular illumination source of the two or more illumination sources in a plurality of directions. The system also includes a stage configured to secure a sample, where the column assembly directs at least a portion of the two or more electron beams onto a portion of the sample.

A multi-beam particle beam system includes a multi-aperture plate having a multiplicity of apertures. During operation, one particle beam of the plurality of particle beams passes through each of the apertures. A multiplicity of electrodes are insulated from the second multi-aperture plate to influence the particle beam passing through the aperture. A voltage supply system for the electrodes includes: a signal a generator to generate a serial sequence of digital signals; a D/A converter to convert the digital signals into a sequence of voltages between an output of the D/A converter and the multi-aperture plate; and a controllable changeover system, which feeds the sequence of voltages successively to different electrodes.

The charged particle beam device includes a charged particle source and a beamlet-forming multiaperture plate. The device also includes a precompensator for reducing aberrations of the beamlets at a target, a scanner for scanning each of the beamlets, an objective lens for focusing each beamlet onto the target, and a controller configured to synchronize the precompensator and the scanner. The precompensator includes: at least one radially variable multiaperture electrode in which the diameter of each aperture thereof scales with the distance of the aperture from the optical axis, z; and at least one cartesianally variable multiaperture electrode in which the diameter of each aperture thereof scales with an x component of the position of the aperture.

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.