A distortion measurement method for an electron microscope image includes: loading a distortion measurement specimen having structures arranged in a lattice to a specimen plane of an electron microscope or a plane conjugate to the specimen plane in order to obtain an electron microscope image of the distortion measurement specimen; and measuring a distortion from the obtained electron microscope image of the distortion measurement specimen.

An electron-optical system for inspecting or reviewing an edge portion of a sample includes an electron beam source configured to generate one or more electron beams, a sample stage configured to secure the sample and an electron-optical column including a set of electron-optical elements configured to direct at least a portion of the one or more electron beams onto an edge portion of the sample. The system also includes a sample position reference device disposed about the sample and a guard ring device disposed between the edge of the sample and the sample position reference device to compensate for one or more fringe fields. One or more characteristics of the guard ring device are adjustable. The system also includes a detector assembly configured to detect electrons emanating from the surface of the sample.

A purpose of the present invention is to provide a charged particle beam device that suppresses an off-axis amount when a field of view moves, said move causing an aberration, and allows large field of view moves to be carried out. In order to achieve the above-mentioned purpose, this charged particle beam device is provided with an objective lens and deflectors for field of view moves, said deflectors deflecting a charged particle beam, and is further provided with an accelerating tube positioned between the objective lens and the deflectors for field of view moves, a power source that applies a voltage to the accelerating tube, and a control device that controls the voltage to be applied to the power source in response to the deflection conditions of the deflectors for field of view moves.

In order to provide an aberration correction system that realizes a charged particle beam of which the anisotropy is reduced or eliminated on a sample surface even in the case where there is magnetic interference between pole stages of an aberration corrector, an correction system includes a line cross position control device (209) which controls a line cross position in the aberration corrector of the charged particle beam so that a designed value and an actually measured value of the line cross position are equal to each other, an image shift amount extraction device (210), and a feedback determination device (211) which determines whether or not changing an excitation amount of the aberration corrector is necessary whether or not changing an excitation amount is necessary from an extracted image shift amount.

A method of inspecting a specimen with an array of primary charged particle beamlets in a charged particle beam device is described. The method includes generating a primary charged particle beam with a charged particle beam emitter; illuminating a multi-aperture lens plate with the primary charged particle beam to generate the array of primary charged particle beamlets; correcting a field curvature with at least two electrodes, wherein the at least two electrodes include aperture openings; directing the primary charged particle beamlets with a lens towards an objective lens; guiding the primary charged particle beamlets through a deflector array arranged within the lens; wherein the combined action of the lens and the deflector array directs the primary charged particle beamlets through a coma free point of the objective lens; and focusing the primary charged particle beamlets on separate locations on the specimen with the objective lens.

A method for inspecting a specimen with an array of primary charged particle beamlets in a charged particle beam device having an optical axis. The method includes generating a primary charged particle beam; illuminating a multi-aperture lens plate with the primary charged particle beam to generate the array of primary charged particle beamlets; and correcting a field curvature of the charged particle beam device with a first and a second field curvature correction electrode. The method further includes applying a voltage to the first and to the second field curvature correction electrode. At least one of the field strength provided by the first and the second field curvature correction electrode varies in a plane perpendicular to the optical axis of the charged particle beam device. The method further includes focusing the primary charged particle beamlets on separate locations on the specimen with an objective lens.

A multi-electron beam system that forms hundreds of beamlets can focus the beamlets, reduce Coulomb interaction effects, and improve resolutions of the beamlets. A Wien filter with electrostatic and magnetic deflection fields can separate the secondary electron beams from the primary electron beams and can correct the astigmatism and source energy dispersion blurs for all the beamlets simultaneously.

An improved method and system for correcting inspection image error are disclosed. An improved method comprises acquiring a set of first beam positions on a test wafer while a wafer stage supporting the test wafer moves at a first velocity; acquiring a set of second beam positions, corresponding to the set of first beam positions, on the test wafer while the wafer stage moves at a second velocity; calculating a beam position displacement of a beam while the wafer stage moves at a third velocity in a range of velocities from the first velocity to the second velocity; and adjusting a beam position of the beam based on the calculated beam position displacement.

A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit forms plural and parallel images of one single electron source by deflecting plural beamlets of a parallel primary-electron beam therefrom, and one objective lens focuses the plural deflected beamlets onto a sample surface and forms plural probe spots thereon. A movable condenser lens is used to collimate the primary-electron beam and vary the currents of the plural probe spots, a pre-beamlet-forming means weakens the Coulomb effect of the primary-electron beam, and the source-conversion unit minimizes the sizes of the plural probe spots by minimizing and compensating the off-axis aberrations of the objective lens and condenser lens.

A scanning electron microscope (SEM) with a swing objective lens (SOL) reduces the off-aberrations to enhance the image resolution, and extends the e-beam scanning angle. The scanning electron microscope comprises a charged particle source, an accelerating electrode, and a swing objective lens system including a pre-deflection unit, a swing deflection unit and an objective lens, all of them are rotationally symmetric with respect to an optical axis. The upper inner-face of the swing deflection unit is tilted an angle to the outer of the SEM and its lower inner-face is parallel to the optical axis. A distribution for a first and second focusing field of the swing objective lens is provided to limit the off-aberrations and can be performed by a single swing deflection unit. Preferably, the two focusing fields are overlapped by each other at least 80 percent.