A particle beam system includes a multiple beam particle source to generate a multiplicity of charged individual particle beams, and a multi-pole lens sequence with first and second multi-pole lens arrays. The particle beam system also includes a controller to control the multi-pole lenses of the multi-pole lens sequence so related groups of multi-pole lenses of the multi-pole lens sequence through which the same individual particle beam passes in each case altogether exert an individually adjustable and focussing effect on the respective individual particle beam passing therethrough.

Disclosed herein is an multi-array lens configured in use to focus a plurality of beamlets of charged particles along a multi-beam path, wherein each lens in the array comprises: an entrance electrode; a focusing electrode and a support. The focusing electrode is down beam of the entrance electrode along a beamlet path and is configured to be at a potential different from the entrance electrode. The support is configured to support the focusing electrode relative to the entrance electrode. The focusing electrode and support are configured so that in operation the lens generates a rotationally symmetrical field around the beamlet path.

Disclosed herein is an multi-array lens configured in use to focus a plurality of beamlets of charged particles along a multi-beam path, wherein each lens in the array comprises: an entrance electrode; a focusing electrode and a support. The focusing electrode is down beam of the entrance electrode along a beamlet path and is configured to be at a potential different from the entrance electrode. The support is configured to support the focusing electrode relative to the entrance electrode. The focusing electrode and support are configured so that in operation the lens generates a rotationally symmetrical field around the beamlet path.

A charged particle beam device for irradiating or inspecting a specimen is described. The charged particle beam device includes a charged particle beam source for generating a primary charged particle beam and a multi-aperture lens plate having a plurality of apertures for forming four or more primary. Two or more electrodes having one opening, e.g. having one opening each, for the primary charged particle beam or the four or more primary beamlets are provided. The charged particle beam device further includes a collimator for deflecting a first primary beamlet, a second primary beamlet, a third primary beamlet, and a fourth primary beamlet of the four or more primary beamlets with respect to each other. The charged particle beam device further includes an objective lens unit having three or more electrodes, each electrode having openings for the four or more primary beamlets.

A charged particle beam device for irradiating or inspecting a specimen is described. The charged particle beam device includes a charged particle beam source for generating a primary charged particle beam and a multi-aperture lens plate having a plurality of apertures for forming four or more primary. Two or more electrodes having one opening, e.g. having one opening each, for the primary charged particle beam or the four or more primary beamlets are provided. The charged particle beam device further includes a collimator for deflecting a first primary beamlet, a second primary beamlet, a third primary beamlet, and a fourth primary beamlet of the four or more primary beamlets with respect to each other. The charged particle beam device further includes an objective lens unit having three or more electrodes, each electrode having openings for the four or more primary beamlets.

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.

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.

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.

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.

Certain improvements of multi-beam raster units such as multi-beam generating units and multi-beam deflector units of a multi-beam charged particle microscopes are provided. The improvements include design, fabrication and adjustment of multi-beam raster units including apertures of specific shape and dimensions. The improvements can enable multi-beam generation and multi-beam deflection or stigmation with higher precision. The improvements can be relevant for routine applications of multi-beam charged particle microscopes, for example in semiconductor inspection and review, where high reliability and high reproducibility and low machine-to-machine deviations are desirable.