Abstract: Charged particle optical devices, systems, and methods are provided. A charged particle optical device can include a dispersing element disposed substantially on a beam axis, the dispersing element being configured to disperse particles of a beam of charged particles by energy in a dispersal plane parallel with the beam axis. The charged particle optical device can include a selector, disposed on the beam axis at a position substantially corresponding to a first crossover plane. The charged particle optical device can include an undispersing element. The charged particle optical device can include a cutoff disposed on the beam axis downstream of the selector at a position substantially corresponding to a second crossover plane on the beam axis. The second crossover plane can be downstream of the first crossover plane. The cutoff can include a material that is opaque to electrons and defining an aperture substantially aligned with the beam axis.

Abstract: 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.

Abstract: The present invention is directed to an electrode component with at least two electrodes or a multipole component as generally known in the art. Each of the electrodes can be provided with a beam neighboring section or end section forming the free electrodes. This section is the section exposed to high voltages, i.e. more than 10 KV, and is intended to nevertheless work very reliable and precise with respect to the guidance and/or controlling of a beam of a charged particle beam in a microscope or lithographic apparatus. This neighboring section are positioned in the vicinity or close to a charged particle beam or even facing it. This bears the preferred advantage that high voltages can be generated by the electrodes or to the electrode component and they can withstand those high voltages. This assists in a better guidance and/or controlling of the charged beam, such as for compensating aberration etc. The beam neighboring section can have a surface configured to face the beam.

Abstract: Optical corrector modules for charged particle columns which comprise split multipoles, according to the present invention include at least one split multipole composed of two multipoles separated by a distance less than 10 mm, 1 m, 100 ?m, and/or 10 ?m. Each of the individual multipoles may comprise at least two electrodes positioned to partially define a beam path through the multipole. According to the present invention, each of the electrodes comprises: a first surface that faces upstream of a charged particle beam when used in the charged particle column; and a second surface that faces downstream of the charged particle beam when used in the charged particle column, wherein the thickness between the first surface and the second surface for each of the electrodes is less than 10 mm, 5 mm, and/or 3 mm. Within the scope of the disclosure, the split multipoles may be electrostatic and may correspond to hexapoles.

Abstract: Compact correctors for correcting spherical aberrations of a particle-optical lens in a charged particle microscope system, according to the present disclosure a strong hexapole configured to generate a strong hexapole field when a voltage is applied to it, and a weak hexapole positioned between the strong hexapole and a sample. The strong hexapole is positioned such that the crossover of a charged particle beam of the charged particle system does not pass through the center of the strong hexapole, such that the strong hexapole field applies at least an A2 aberration and a D4 aberration to the charged particle beam. The weak hexapole is further positioned or otherwise configured such that, when a voltage is applied to the weak hexapole it generates a weak hexapole field that applies at least a combination A2 aberration and a combination D4 aberration to the charged particle beam of the charged particle microscopy system.

Abstract: 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.

Abstract: An electron optical module for providing an off-axial electron beam with a tunable coma, according to the present disclosure includes a structure positioned downstream of an electron source and an electron lens assembly positioned between the structure and the electron source. The structure generates a decelerating electric field, and is positioned to prevent the passage of electrons along the optical axis of the electron lens assembly. The electron optical module further includes a micro-lens that is not positioned on the optical axis of the electron lens assembly and is configured to apply a lensing effect to an off-axial election beam. Aberrations applied to the off-axial electron beam by the micro-lens and the electron lens assembly combine so that a coma of the off-axial beam has a desired value in a downstream plane.

Abstract: Electrostatic mirror chromatic aberration (Cc) correctors, according to the present disclosure, comprise an electrostatic electron mirror that itself comprises a multipole. The electrostatic electron mirror is positioned within the corrector such that, when the corrector is in use, an electron beam passing through the corrector is not incident on the electrostatic electron mirror along the optical axis of the mirror. The mirror object distance of the electrostatic mirror is equal to the mirror image distance of the electrostatic mirror, and the electrostatic mirror is configured such that the electrostatic mirror applies no dispersion or coma aberration to the electron beam. The multipole is positioned in the mirror plane of the electrostatic electron mirror, and in some embodiments the multipole is a quadrupole.

Abstract: An electron optical module for providing an off-axial electron beam with a tunable coma, according to the present disclosure includes a structure positioned downstream of an electron source and an electron lens assembly positioned between the structure and the electron source. The structure generates a decelerating electric field, and is positioned to prevent the passage of electrons along the optical axis of the electron lens assembly. The electron optical module further includes a micro-lens that is not positioned on the optical axis of the electron lens assembly and is configured to apply a lensing effect to an off-axial election beam. Aberrations applied to the off-axial electron beam by the micro-lens and the electron lens assembly combine so that a coma of the off-axial beam has a desired value in a downstream plane.

Abstract: An adjustable magnetic field free objective lens for a charged particle microscope is disclosed herein. An example charged particle microscope at least includes first and second optical elements arranged on opposing sides of a sample plane, a third optical element arranged around the sample plane, and a controller coupled to control the first, second and third optical elements. The controller coupled to excite the first and second optical elements to generate first and second magnetic lenses, the first and second magnetic lenses formed on opposing sides of the sample plane and oriented in the same direction, and excite the third optical element to generate a third magnetic lens at the sample plane that is oriented in an opposite direction, where a ratio of the excitation of the third optical element to the excitation of the first and second optical elements adjusts a magnetic field at the sample plane.

Abstract: An adjustable magnetic field free objective lens for a charged particle microscope is disclosed herein. An example charged particle microscope at least includes first and second optical elements arranged on opposing sides of a sample plane, a third optical element arranged around the sample plane, and a controller coupled to control the first, second and third optical elements. The controller coupled to excite the first and second optical elements to generate first and second magnetic lenses, the first and second magnetic lenses formed on opposing sides of the sample plane and oriented in the same direction, and excite the third optical element to generate a third magnetic lens at the sample plane that is oriented in an opposite direction, where a ratio of the excitation of the third optical element to the excitation of the first and second optical elements adjusts a magnetic field at the sample plane.

Abstract: Methods and systems for investigating a sample using a dual beam bifocal charged particle microscope, according to the present disclosure include emitting a plurality of charged particles toward the sample, forming the plurality of charged particles into a first charged particle beam and a second charged particle beam, and modifying the focal properties of at least one of the first charged particle beam and the second charged particle beam. The focal properties of at least one of the first charged particle beam and the second charged particle beam is modified such that the corresponding focal planes of the first charged particle beam and the second charged particle beam are different.

Abstract: A multi-electron beam imaging apparatus is disclosed herein. An example apparatus at least includes an electron source for producing a precursor electron beam, an aperture plate comprising an array of apertures for producing an array of electron beams from said precursor electron beam, an electron beam column for directing said array of electron beams onto a specimen, where the electron beam column is configured to have a length less than 300 mm, and where the electron beam column comprises a single individual beam crossover plane in which each of said electron beams forms an intermediate image of said electron source, and a single common beam crossover plane in which the electron beams in the array cross each other.

Abstract: Variable multi-beam charged particle devices for inspection of a sample include a multi-beam source that produces a plurality of charged particle beamlets, an objective lens, a sample holder for holding the sample between the objective lens and the multi-beam source, and a focusing column that directs the plurality of charged particle beamlets so that they are incident upon the sample. The focusing column directs the plurality of charged beams such that there are one or more crossovers of the plurality of charged particle beamlets, where each crossover corresponds to a point where the plurality of charged particle beamlets pass through a common location. The variable multi-beam charged particle devices also include a variable aperture that is configured to vary the current of the plurality of charged particle beamlets, and which is located at a final crossover of the one or more crossovers that is most proximate to the sample.

Abstract: A charged particle imaging apparatus comprising: A specimen holder, for holding a specimen; A particle-optical column, for: Producing a plurality of charged particle beams, by directing a progenitor charged particle beam onto an aperture plate having a corresponding plurality of apertures within a footprint of the progenitor beam; Directing said beams toward said specimen, wherein: Said aperture plate comprises a plurality of different zones, which comprise mutually different aperture patterns, arranged within said progenitor beam footprint; The particle-optical column comprises a selector device, located downstream of said aperture plate, for selecting a beam array from a chosen one of said zones to be directed onto the specimen.

Abstract: 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.

Abstract: Techniques for multi-beam scanning transmission charged particle microscopy are disclosed herein. An example apparatus at least includes a charged particle beam column to produce a plurality of charged particle beams and irradiate a specimen with each of the plurality of charged particle beams, and an imaging system to collect charged particles of each of the charged particle beams of the plurality of charged particle beams that traverse the specimen during said irradiation, and to direct each charged particle beam of the plurality of the charged particle beams after traversing the sample onto a detector, where each charged particle beam includes a barycenter, and where the detector is disposed in an intermediate location between a back focal plane and an imaging plane of the imaging system.

Abstract: A multi-electron beam imaging apparatus is disclosed herein. An example apparatus at least includes an electron source for producing a precursor electron beam, an aperture plate comprising an array of apertures for producing an array of electron beams from said precursor electron beam, an electron beam column for directing said array of electron beams onto a specimen, where the electron beam column is configured to have a length less than 300 mm, and where the electron beam column comprises a single individual beam crossover plane in which each of said electron beams forms an intermediate image of said electron source, and a single common beam crossover plane in which the electron beams in the array cross each other.

Abstract: A charged particle imaging apparatus comprising: A specimen holder, for holding a specimen; A particle-optical column, for: Producing a plurality of charged particle beams, by directing a progenitor charged particle beam onto an aperture plate having a corresponding plurality of apertures within a footprint of the progenitor beam; Directing said beams toward said specimen, wherein: Said aperture plate comprises a plurality of different zones, which comprise mutually different aperture patterns, arranged within said progenitor beam footprint; The particle-optical column comprises a selector device, located downstream of said aperture plate, for selecting a beam array from a chosen one of said zones to be directed onto the specimen.

Abstract: A method of operating a charged particle microscope comprising the following steps: Providing a specimen on a specimen holder; Using a source to produce a beam of charged particles that is subject to beam current fluctuations; Employing a beam current sensor, located between said source and specimen holder, to intercept a part of the beam and produce an intercept signal proportional to a current of the intercepted part of the beam, the beam current sensor comprising a hole arranged to pass a beam probe with an associated probe current; Scanning said probe over the specimen, thereby irradiating the specimen with a specimen current, with a dwell time associated with each scanned location on the specimen; Using a detector to detect radiation emanating from the specimen in response to irradiation by said probe, and producing an associated detector signal; Using said intercept signal as input to a compensator to suppress an effect of said current fluctuations in said detector signal, wherein: The beam current