The present invention quickly calculates values of optimal excitation parameters which are set in lenses in multiple stages. A multi charged particle beam adjustment method includes forming a multi charged particle beam, calculating, for each of lenses in two or more stages disposed corresponding to object lenses in two or more stages, a first rate of change and a second rate of change in response to change in at least an excitation parameter, the first rate of change being a rate of change in a demagnification level of a beam image of the multi charged particle beam, the second rate of change being a rate of change in a rotation level of the beam image, and calculating a first amount of correction to the excitation parameter of each of the lenses based on an amount of correction to the demagnification level and the rotation level of the beam image, the first rate of change, and the second rate of change.

The present invention quickly calculates values of optimal excitation parameters which are set in lenses in multiple stages. A multi charged particle beam adjustment method includes forming a multi charged particle beam, calculating, for each of lenses in two or more stages disposed corresponding to object lenses in two or more stages, a first rate of change and a second rate of change in response to change in at least an excitation parameter, the first rate of change being a rate of change in a demagnification level of a beam image of the multi charged particle beam, the second rate of change being a rate of change in a rotation level of the beam image, and calculating a first amount of correction to the excitation parameter of each of the lenses based on an amount of correction to the demagnification level and the rotation level of the beam image, the first rate of change, and the second rate of change.

It is provided a charged particle beam manipulation device for a plurality of charged particle beamlets, the charged particle beam manipulation device including a lens having a main optical axis, the lens including at least a first array of multipoles, each multipole of the first array of multipoles configured to compensate for a lens deflection force on a respective charged particle beamlet of the plurality of charged particle beamlets, the lens deflection force being a deflection force produced by the lens on the respective charged particle beamlet towards the main optical axis of the lens.

There is provided a scanning electron microscope which has a sample chamber capable of being evacuated to a low vacuum. The scanning electron microscope includes an electron gun for emitting an electron beam, an objective lens for focusing the emitted beam onto a sample, and a sample chamber in which the sample is housed. The objective lens includes an inner polepiece, an outer polepiece disposed outside the inner polepiece and facing the sample chamber, at least one through-hole extending through the inner and outer polepieces, and at least one cover member that closes off the through-hole. An opening is formed between the inner polepiece and the outer polepiece. The objective lens causes leakage of magnetic field from the opening toward the sample. The sample chamber has a degree of vacuum lower than that in an inner space that forms an electron beam path inside the inner polepiece.

There is provided a scanning electron microscope which has a sample chamber capable of being evacuated to a low vacuum. The scanning electron microscope includes an electron gun for emitting an electron beam, an objective lens for focusing the emitted beam onto a sample, and a sample chamber in which the sample is housed. The objective lens includes an inner polepiece, an outer polepiece disposed outside the inner polepiece and facing the sample chamber, at least one through-hole extending through the inner and outer polepieces, and at least one cover member that closes off the through-hole. An opening is formed between the inner polepiece and the outer polepiece. The objective lens causes leakage of magnetic field from the opening toward the sample. The sample chamber has a degree of vacuum lower than that in an inner space that forms an electron beam path inside the inner polepiece.

A particle beam system includes: a multi-beam particle source configured to generate a multiplicity of particle beams; an imaging optical unit configured to image an object plane in particle-optical fashion into an image plane and direct the multiplicity of particle beams on the image plane; and a field generating arrangement configured to generate electric and/or magnetic deflection fields of adjustable strength in regions close to the object plane. The particle beams are deflected in operation by the deflection fields through deflection angles that depend on the strength of the deflection fields.

A particle beam system includes: a multi-beam particle source configured to generate a multiplicity of particle beams; an imaging optical unit configured to image an object plane in particle-optical fashion into an image plane and direct the multiplicity of particle beams on the image plane; and a field generating arrangement configured to generate electric and/or magnetic deflection fields of adjustable strength in regions close to the object plane. The particle beams are deflected in operation by the deflection fields through deflection angles that depend on the strength of the deflection fields.

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.

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.

Multiple electron beamlets are split from a single electron beam. The electron beam passes through an acceleration tube, a beam-limiting aperture, an anode disposed between an electron beam source and the acceleration tube, a focusing lens downstream from the beam-limiting aperture, and a micro aperture array downstream from the acceleration tube. The micro aperture array generates beamlets from the electron beam. The electron beam can be focused from a divergent illumination beam into a telecentric illumination beam.