In some embodiments, a system for measuring magnetic fields produced within a microscope comprising an electromagnetic lens includes a sensor support element configured to be mounted to a distal end of an elongated support member that is configured to be inserted into the microscope, and a magnetic field sensor supported by the sensor support element, the magnetic field sensor being configured to sense magnetic fields at a position within the electron microscope at which specimens are imaged during operation of the microscope.

In some embodiments, a system for measuring magnetic fields produced within a microscope comprising an electromagnetic lens includes a sensor support element configured to be mounted to a distal end of an elongated support member that is configured to be inserted into the microscope, and a magnetic field sensor supported by the sensor support element, the magnetic field sensor being configured to sense magnetic fields at a position within the electron microscope at which specimens are imaged during operation of the microscope.

A multi charged particle beam irradiation apparatus includes a shaping aperture array substrate, where plural openings are formed as an aperture array, to shape multi-beams by making a region including entire plural openings irradiated by a charged particle beam, and making portions of a charged particle beam individually pass through a corresponding one of the plural openings; and a plurality of stages of lenses, arranged such that a reduction ratio of multi-beams by at least one lens of a stage before the last stage lens is larger than that of the multi-beams by the last stage lens, to correct distortion of a formed image obtained by forming an image of the aperture array by the multi-beams, and to form the image of the aperture array by the multi-beams at a height position between the last stage lens and a last-but-one stage lens, and at the surface of a target object.

A multi charged particle beam irradiation apparatus includes a shaping aperture array substrate, where plural openings are formed as an aperture array, to shape multi-beams by making a region including entire plural openings irradiated by a charged particle beam, and making portions of a charged particle beam individually pass through a corresponding one of the plural openings; and a plurality of stages of lenses, arranged such that a reduction ratio of multi-beams by at least one lens of a stage before the last stage lens is larger than that of the multi-beams by the last stage lens, to correct distortion of a formed image obtained by forming an image of the aperture array by the multi-beams, and to form the image of the aperture array by the multi-beams at a height position between the last stage lens and a last-but-one stage lens, and at the surface of a target object.

A scanning electron microscope comprises three objective lenses, including a distant objective lens and a close objective lens, which are of conventional type, and an immersion objective lens of the immersion type below the distant objective lens and the close objective lens. These three objective lenses can be controlled independently, therefor different combinations of active objective lenses can be achieved. The scanning electron microscope therefore offers various imaging modes. There is a possibility to switch between these imaging modes and therefore, choose the most suitable way of imaging for given application.

A scanning electron microscope comprises three objective lenses, including a distant objective lens and a close objective lens, which are of conventional type, and an immersion objective lens of the immersion type below the distant objective lens and the close objective lens. These three objective lenses can be controlled independently, therefor different combinations of active objective lenses can be achieved. The scanning electron microscope therefore offers various imaging modes. There is a possibility to switch between these imaging modes and therefore, choose the most suitable way of imaging for given application.

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.

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 present invention provides an electrode assembly comprising two or more electrodes arranged around a primary axis forming a non-cylindrical channel space. General electronic apparatus/device, particularly apparatus of charged-particle beam such as electron microscope, may use the electrode assembly to create an optimized pattern of electrical field within non-cylindrical channel space. When the electrode assembly is used as a beam deflector in a magnetic objective lens, the electrical field within the central channel space can be co-optimized with the magnetic field for reducing aberration(s) such as distortion, field curvature, astigmatism, and chromatic aberration, after the beam passes through the central channel space.

The system described herein relates to a particle beam apparatus for analyzing and/or for processing an object and to a method for operating a particle beam apparatus. The particle beam apparatus is designed for example as an electron beam apparatus and/or an ion beam apparatus. The particle beam apparatus comprises a beam deflection device, for example an objective lens, which is provided with a first coil and a second coil. The first coil is operated with a first coil current. The second coil is operated with a second coil current. The first coil current and/or the second coil current may always be controlled in such a way that the sum of the first coil current and the second coil current (the summation current) or the difference between the first coil current and the second coil current (the difference current) is controlled to a setpoint value.