A method includes operating a multiple particle beam system at different working points. The numerical aperture can be set for each of the working points in such a way that the resolution of the multiple particle beam system is optimal. In the process, the beam pitch between adjacent individual particle beams on the sample to be scanned is kept constant as a boundary condition. There are no mechanical reconfigurations of the system whatsoever for the purposes of varying the numerical aperture.

An electrostatic lens for transporting charged particles in an axial direction includes a first group of first electrodes configured to receive a first DC potential from a DC voltage source, and a second group of second electrodes configured to receive a second DC potential from the DC voltage source different from the first DC potential. The first electrodes are interdigitated with the second electrodes. The first group and/or the second group has a geometric feature that progressively varies along the axial direction. The lens generates an axial potential profile that progressively changes along the axial direction, and thereby reduces geometrical aberrations. The lens may be part of a charged particle processing apparatus such as, for example, a mass spectrometer or an electron microscope.

The invention relates to charged particle beam generator comprising a charged particle source for generating a charged particle beam, a collimator system comprising a collimator structure with a plurality of collimator electrodes for collimating the charged particle beam, a beam source vacuum chamber comprising the charged particle source, and a generator vacuum chamber comprising the collimator structure and the beam source vacuum chamber within a vacuum, wherein the collimator system is positioned outside the beam source vacuum chamber. Each of the beam source vacuum chamber and the generator vacuum chamber may be provided with a vacuum pump.

A particle beam system and, such as a multi-beam particle microscope, can have a current intensity of individual particle beams that is flexibly set over large value ranges without structural modifications. The particle beam system can include a condenser lens system, a pre-multi-lens array with a specific pre-counter electrode and a pre-multi-aperture plate, and a multi-lens array. The system can includes a controller to supply adjustable excitations to the condenser lens system and the pre-counter electrode so that the charged particles are incident on the pre-multi-aperture plate in telecentric manner.

The invention relates to charged particle beam generator comprising a charged particle source for generating a charged particle beam, a collimator system comprising a collimator structure with a plurality of collimator electrodes for collimating the charged particle beam, a beam source vacuum chamber comprising the charged particle source, and a generator vacuum chamber comprising the collimator structure and the beam source vacuum chamber within a vacuum, wherein the collimator system is positioned outside the beam source vacuum chamber. Each of the beam source vacuum chamber and the generator vacuum chamber may be provided with a vacuum pump.

A particle beam system includes: a particle source to generate a beam of charged particles; a first multi-lens array including a first multiplicity of individually adjustable and focusing particle lenses so that at least some of the particles pass through openings in the multi-lens array in the form of a plurality of individual particle beams; a second multi-aperture plate including a multiplicity of second openings downstream of the first multi-lens array so that some of the particles which pass the first multi-lens array impinge on the second multi-aperture plate and some of the particles which pass the first multi-lens array pass through the openings in the second multi-aperture plate; and a controller configured to supply an individually adjustable voltage to the particle lenses of the first multi-lens array and thus individually adjust the focusing of the associated particle lens for each individual particle beam.

A charged particle multi-beam device includes a charged particle source, a collimator lens, a multi-light-source forming unit, and a reduction projection optical system. The multi-light-source forming unit has first to third porous electrodes disposed side by side in an optical axis direction. A plurality of holes for causing the multi-beams to pass is formed in each of the first to third porous electrodes. The first porous electrode and the third porous electrode have the same potential and the second porous electrode has potential different from the potential of the first porous electrode and the third porous electrode. A diameter of the holes on the second porous electrode is formed larger further away from an optical axis such that a surface on which the multi-light sources are located is formed in a shape convex to the charged particle source side.

The invention relates to a charged particle beam device for inspection of a specimen with a plurality of charged particle beamlets. The charged particle beam device comprises a specimen holder for holding a specimen; a source for producing a beam of charged particles; and an illuminator for converting said beam of charged particles into a plurality of charged particle beamlets and directing said plurality of charged particle beamlets onto said specimen. According to the disclosure, the illuminator comprises a multi-aperture lens plate having a plurality of apertures for defining the corresponding plurality of charged particle beamlets; as well as at least a first electrode for generating an electrical field at a surface of the multi-aperture lens plate. The apertures in said multi-aperture lens plate have a noncircular cross-sectional shape to correct for neighbouring aperture induced aberrations. This allows for decreased spot size, and with this imaging resolution of the device is increased.

An objective lens arrangement includes a first, second and third pole pieces, each being substantially rotationally symmetric. The first, second and third pole pieces are disposed on a same side of an object plane. An end of the first pole piece is separated from an end of the second pole piece to form a first gap, and an end of the third pole piece is separated from an end of the second pole piece to form a second gap. A first excitation coil generates a focusing magnetic field in the first gap, and a second excitation coil generates a compensating magnetic field in the second gap. First and second power supplies supply current to the first and second excitation coils, respectively. A magnetic flux generated in the second pole piece is oriented in a same direction as a magnetic flux generated in the second pole piece.

The invention relates to charged particle beam generator comprising a charged particle source for generating a charged particle beam, a collimator system comprising a collimator structure with a plurality of collimator electrodes for collimating the charged particle beam, a beam source vacuum chamber comprising the charged particle source, and a generator vacuum chamber comprising the collimator structure and the beam source vacuum chamber within a vacuum, wherein the collimator system is positioned outside the beam source vacuum chamber. Each of the beam source vacuum chamber and the generator vacuum chamber may be provided with a vacuum pump.