A focus adjustment method for a charged particle beam device having a magnetic field lens used for focus adjustment and an astigmatism corrector includes: acquiring a plurality of first images by varying an excitation current of the magnetic field lens within a focus search range, and determining a reference value of the excitation current; removing hysteresis from the magnetic field lens by setting the excitation current of the magnetic field lens outside the focus search range before and after varying the excitation current of the magnetic field lens within the focus search range; and acquiring a plurality of second images by varying the excitation current of the magnetic field lens using the reference value as a reference and varying a stigma correction value of the astigmatism corrector at each excitation current, and then determining optimum values of the excitation current and the stigma correction value.

Provided is a charged particle beam device that can impart a function of an energy filter to even a small BSE detector. The charged particle beam device includes a fluorescent substance that converts charged particles generated by irradiation of a sample with a charged particle beam into light; a detector that detects the light emitted from the fluorescent substance; a light guide element for guiding the light from the fluorescent substance to the detector; a light amount adjuster that adjusts the amount of light that is received by the detector through the fluorescent substance and the light guide element; and a control unit that controls the light amount adjuster.

Provided is a charged particle beam device that can impart a function of an energy filter to even a small BSE detector. The charged particle beam device includes a fluorescent substance that converts charged particles generated by irradiation of a sample with a charged particle beam into light; a detector that detects the light emitted from the fluorescent substance; a light guide element for guiding the light from the fluorescent substance to the detector; a light amount adjuster that adjusts the amount of light that is received by the detector through the fluorescent substance and the light guide element; and a control unit that controls the light amount adjuster.

A charged particle beam system includes a charged particle source that generates a first charged particle beam and a multi beam generator that generates a plurality of charged particle beamlets from an incoming first charged particle beam. Each individual beamlet is spatially separated from other beamlets. The charged particle beam system also includes an objective lens that focuses incoming charged particle beamlets in a first plane so that a first region in which a first individual beamlet impinges in the first plane is spatially separated from a second region in which a second individual beamlet impinges in the first plane. The charged particle beam system also includes a projection system and a detector system including a plurality of individual detectors. The projection system images interaction products leaving the first region within the first plane due to impinging charged particles onto a first detector and images interaction products leaving the second region in the first plane onto a second detector.

A charged particle beam system includes a charged particle source that generates a first charged particle beam and a multi beam generator that generates a plurality of charged particle beamlets from an incoming first charged particle beam. Each individual beamlet is spatially separated from other beamlets. The charged particle beam system also includes an objective lens that focuses incoming charged particle beamlets in a first plane so that a first region in which a first individual beamlet impinges in the first plane is spatially separated from a second region in which a second individual beamlet impinges in the first plane. The charged particle beam system also includes a projection system and a detector system including a plurality of individual detectors. The projection system images interaction products leaving the first region within the first plane due to impinging charged particles onto a first detector and images interaction products leaving the second region in the first plane onto a second detector.

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.

Systems and methods are provided for compensating dispersion of a beam separator in a single-beam or multi-beam apparatus. Embodiments of the present disclosure provide a dispersion device comprising an electrostatic deflector and a magnetic deflector configured to induce a beam dispersion set to cancel the dispersion generated by the beam separator. The combination of the electrostatic deflector and the magnetic deflector can be used to keep the deflection angle due to the dispersion device unchanged when the induced beam dispersion is changed to compensate for a change in the dispersion generated by the beam separator. In some embodiments, the deflection angle due to the dispersion device can be controlled to be zero and there is no change in primary beam axis due to the dispersion device.

Systems and methods are provided for compensating dispersion of a beam separator in a single-beam or multi-beam apparatus. Embodiments of the present disclosure provide a dispersion device comprising an electrostatic deflector and a magnetic deflector configured to induce a beam dispersion set to cancel the dispersion generated by the beam separator. The combination of the electrostatic deflector and the magnetic deflector can be used to keep the deflection angle due to the dispersion device unchanged when the induced beam dispersion is changed to compensate for a change in the dispersion generated by the beam separator. In some embodiments, the deflection angle due to the dispersion device can be controlled to be zero and there is no change in primary beam axis due to the dispersion device.

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.