An observation apparatus and method that avoids drawbacks of a Lorentz method and observes a weak scatterer or a phase object with in-focus, high resolution, and no azimuth dependency, by a Foucault method observation using a hollow-cone illumination that orbits and illuminates an incident electron beam having a predetermined inclination angle, an electron wave is converged at a position (height) of an aperture plate downstream of a sample, and a bright field condition in which a direct transmitted electron wave of the sample passes through the aperture plate, a dark field condition in which the transmitted electron wave is shielded, and a Schlieren condition in which approximately half of the transmitted wave is shielded as a boundary condition of both of the above conditions are controlled, and a spatial resolution of the observation image is controlled by selecting multiple diameters and shapes of the opening of the aperture plate.

A multi-charged particle beam writing apparatus according to one aspect of the present invention includes a region setting unit configured to set, as an irradiation region for a beam array to be used, the region of the central portion of an irradiation region for all of multiple beams of charged particle beams implemented to be emittable by a multiple beam irradiation mechanism, and a writing mechanism, including the multiple beam irradiation mechanism, configured to write a pattern on a target object with the beam array in the region of the central portion having been set in the multiple beams implemented.

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.

A multi-charged particle beam writing apparatus according to one aspect of the present invention includes a region setting unit configured to set, as an irradiation region for a beam array to be used, the region of the central portion of an irradiation region for all of multiple beams of charged particle beams implemented to be emittable by a multiple beam irradiation mechanism, and a writing mechanism, including the multiple beam irradiation mechanism, configured to write a pattern on a target object with the beam array in the region of the central portion having been set in the multiple beams implemented.

The present disclosure provides a magnetic immersion electron gun and a method of generating an electron beam using a magnetic immersion electron gun. The electron gun includes a magnetic lens forming a magnetic field, a cathode tip disposed in the magnetic field, and a multi-filament heater configured to directly heat the cathode tip to emit electrons through the magnetic lens. The multi-filament heater includes a first filament connected at each end to first and second positive terminals of a power source and a second filament connected at each end to first and second negative terminals of the power source. The first positive terminal, the second positive terminal, the first negative terminal, and the second negative terminal are arranged alternately around the cathode tip such that the first filament and the second filament intersect at the cathode tip and a resultant magnetic force applied to the cathode tip is reduced.

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.

Embodiments of the present invention disclose methods and systems for producing an adaptive pencil beam having an adjustable lateral beam size and Bragg-peak width. According to one disclosed embodiment, an apparatus for producing an adaptive pencil beam is disclosed. The apparatus includes a set of momentum band expanders configured to widen a momentum spread of a pencil beam, where a momentum band expander is selected from the set of momentum band expanders to receive the pencil beam, and a slit at dispersive focus of two dipole magnets to adjust a width of a Bragg-peak of the pencil beam. According to another disclosed embodiment, a method for producing an adaptive pencil beam with an adjustable lateral beam is disclosed. The method includes selecting a scatter foil, or setting of a defocusing/focusing magnet, and adjusting a lateral size of the pencil beam.

The present invention is related to an apparatus for transporting a charged particle beam. The apparatus may include means for scanning the charged particle beam on a target, a dipole magnet arranged upstream of the means for scanning, at least three quadrupole lenses arranged between the dipole magnet and the means for scanning and means for adjusting the field strength of said at least three quadrupole lenses in function of the scanning angle of the charged particle beam. The apparatus can be made at least single achromatic.

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.