There is provided a method which is for use in a charged particle beam system including an illumination system equipped with an aberration corrector having a plurality of stages of multipole elements and a transfer lens system disposed between the multipole elements, the method being capable of correcting distortion in a shadow of an aperture of the illumination system. The method involves varying excitations of the transfer lens system to correct distortion in the shadow of the aperture of the illumination system.

A system and method of a tilt-column electron beam imaging system is disclosed. The system may include an imaging sub-system. The imaging sub-system may include a plurality of electron beam sources configured to generate a plurality of beamlets. The imaging sub-system may further include a plurality of tilt-illumination columns, where a respective tilt-illumination column is configured to receive a respective beamlet from a respective electron beam source. For the system and method, a first tilt axis of a first tilt-illumination column may be orientated along a first angle and at least one additional tilt axis of at least one additional tilt-illumination column may be orientated along at least one additional angle different from the first angle, where each of the plurality of beamlets pass through a first common crossover volume.

In one embodiment, a multi charged particle beam writing apparatus includes an emitter that emits a charged particle beam, an aperture plate in which a plurality of openings are formed and that forms multiple beams by allowing the charged particle beam to pass through the plurality of openings, a blanking plate provided with a plurality of blankers that each perform blanking deflection on a corresponding beam included in the multiple beams, a stage on which a substrate irradiated with the multiple beams, a detector that detects a reflection charged particle from the substrate, feature amount calculation circuitry that calculates a feature amount of an aperture image based on a detection value of the detector, and aberration correction circuitry that corrects aberration of the charged particle beam based on the feature amount.

An electron microscope includes a monochromator, an image acquiring portion for obtaining an electron microscope image containing interference fringes of the electron beam formed by an aperture located behind the monochromator, a line profile acquiring portion for obtaining a plurality of line profiles passing through the center of the aperture on the EM image, an energy dispersion direction identifying portion for identifying the direction of energy dispersion of the monochromator on the basis of the line profiles obtained by the line profile acquiring portion, and an optics controller for controlling an optical system on the basis of a line profile in the direction of energy dispersion to bring the focal plane for the electron beam exiting from the monochromator into coincidence with the achromatic plane.

A multi charged particle beam inspection apparatus includes a plurality of sensors, arranged inside or on a periphery of a secondary electron image acquisition mechanism, to measure a plurality of interfering factors, a determination circuit to determine, for each interfering factor, whether change exceeding a corresponding threshold is a first case which returns to the original state within a predetermined time period, or a second case which does not return to the original state even if the predetermined time period has passed, and a comparison circuit to input a reference image of a region corresponding to the secondary electron image acquired, and compare the secondary electron image with the reference image, wherein in the case where change of the second case occurs, the secondary electron image acquisition mechanism suspends the acquisition operation of the secondary electron image, and calibrates a change amount of the multiple charged particle beams.

There is provided a liner tube capable of reducing the effects of magnetic field variations on an electron beam. The liner tube (10) is disposed inside the electron optical column (2) of an electron microscope (100). The interior of the tube (10) forms a path for the electron beam (EB). The liner tube (10) has a first cylindrical member (110) that is made of copper, gold, silver, or an alloy consisting principally of one of these metals.

There is provided a liner tube capable of reducing the effects of magnetic field variations on an electron beam. The liner tube (10) is disposed inside the electron optical column (2) of an electron microscope (100). The interior of the tube (10) forms a path for the electron beam (EB). The liner tube (10) has a first cylindrical member (110) that is made of copper, gold, silver, or an alloy consisting principally of one of these metals.

A multi-beam inspection apparatus including an improved source conversion unit is disclosed. The improved source conversion unit may comprise a micro-structure deflector array including a plurality of multipole structures. The micro-deflector deflector array may comprise a first multipole structure having a first radial shift from a central axis of the array and a second multipole structure having a second radial shift from the central axis of the array. The first radial shift is larger than the second radial shift, and the first multipole structure comprises a greater number of pole electrodes than the second multipole structure to reduce deflection aberrations when the plurality of multipole structures deflects a plurality of charged particle beams.

A multipole element for creating a magnetic multipole field or for creating an electric-magnetic multipole field for a particle beam system such as a scanning electron microscope, for example, comprises: a tube surrounding a central axis of the multipole element; an external space assembly arranged outside of the tube and a vacuum space assembly arranged within the tube. The external space assembly comprises: a magnetically conductive circumferential pole piece surrounding the tube; a plurality of magnetically conductive supports arranged so as to be distributed around the central axis and extending from the circumferential pole piece up to an outer wall surface of the tube; and a plurality of coils. The vacuum space assembly comprises a plurality of magnetically conductive pole pieces arranged so as to be distributed around the central axis and extending from the tube in the direction of the central axis.

A method of operating a charged particle microscope comprises: providing settings of a focus, an x-stigmator and an y-stigmator of the charged particle microscope; and then repeatedly performing adjusting the charged particle microscope to the settings, recording an image of an object using the settings, determining a sharpness measure from the recorded image, and changing at least one of the settings of the focus, the x-stigmator and the y-stigmator based on the sharpness measure until a stop criterion is fulfilled. Herein, the determining of the sharpness measure comprises: determining an orientation of an intensity gradient at each of a plurality of locations within one of the recorded image and a processed image generated by processing the recorded image, and determining the sharpness measure based on the plurality of determined orientations.