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 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 sample display method by means of a scanning electron microscope comprises at most one active objective lens located above a first scanning element and a second scanning element. A primary electron beam is deflected so as to be focused by an objective lens so that the beam propagates from the second scanning element towards a sample approximately parallel to the SEM optical axis, wherein the sample is also tilted relative to the SEM optical axis by an angle other than 90, or it is a sample with distinct topography.

A multiple charged particle beam writing method includes emitting multiple charged particle beams, and performing writing with the multiple charged particle beams, during a movement of a stage having a target object thereon in a reverse direction to a movement direction of the writing, to at least two stripe regions in a plurality of stripe regions aligned, on the target object, partially overlapping with each other in the first direction being linearly independent with respect to the movement direction of the writing, while repeatedly switching an irradiation region, in the first direction, by a deflection amount having a width larger than a beam pitch size of the multiple charged particle beams, and applying irradiation with the multiple charged particle beams at each time of the switching the irradiation region.

Systems and methods of imaging a sample using a charged-particle beam apparatus are disclosed. The apparatus may include a charged-particle source configured to emit charged particles, an aperture plate configured to form a primary charged-particle beam along a primary optical axis from the emitted charged particles, a plurality of primary charged-particle beam deflectors configured to deflect the primary charged-particle beam to be incident on a surface of a sample to define a center of a field-of-view (FOV), and a controller including circuitry configured to apply a first excitation signal to a primary charged-particle beam deflector of the plurality of primary charged-particle beam deflectors to cause the primary charged-particle beam to scan a portion of the FOV of the sample, and apply a second excitation signal to cause the primary-charged particle beam deflector to compensate for an off-axis aberration of the primary charged-particle beam in the portion of the FOV.

A charged particle beam device, method, and non-transitory computer-readable medium for scan distortion correction that includes receiving a beam desired ending position, receiving a beam starting position, calculating a director signal based on the beam starting position and the beam desired ending position, calculating a corrected signal based on the beam starting position, the director signal, a distortion model, and the beam desired ending position, and transmitting an instruction including the corrected signal to a beam director, where the corrected signal causes the beam director to move a beam of charged particles passing therethrough from the beam starting position to a beam corrected ending position.

A charged particle beam device, method, and non-transitory computer-readable medium for scan distortion correction that includes receiving a beam desired ending position, receiving a beam starting position, calculating a director signal based on the beam starting position and the beam desired ending position, transmitting a director instruction including the director signal to the beam director, calculating a corrector signal based on the beam starting position, the director signal, a distortion model, and the beam desired ending position, and transmitting a corrector instruction including the corrector signal to the beam corrector, wherein the director signal causes the beam director to move the beam of charged particles, the corrector signal causes the beam corrector to move the beam of charged particles, and the beam director and beam corrector move the beam of charged particles from the beam starting position to a beam corrected ending position.

According to one aspect of the present invention, a multi-beam image acquisition apparatus, includes: a deflector configured to cause at least one detector of the detector array to detect a signal waveform caused by an incidence position of a detected secondary electron beam on the at least one detector of the detector array detecting multiple secondary electron beams emitted due to irradiating an object with multiple primary electron beams in a case that a predetermined period of time has passed from start of irradiation of the multiple primary electron beams by deflecting the multiple secondary electron beams; a deviation amount calculation circuit configured to calculate a deviation amount of the incidence position using the signal waveform; and a corrector configured to correct incidence positions of the multiple secondary electron beams on the detector array so as to reduce the deviation amount.

A multi-beam charged particle microscope and a method of operating a multi-beam charged particle microscope for wafer inspection with high throughput and with high resolution and high reliability are provided. The method of operation and the multi-beam charged particle beam microscope comprises a mechanism for a synchronized scanning operation and image acquisition by a plurality of charged particle beamlets according a selected scan program, wherein the selected scan program can be selected according an inspection task from different scan programs.

Systems, apparatuses, and methods for adjusting distortion in images. Embodiments include obtaining a plurality of images; determining alignment differences between a plurality of features on the plurality of images and corresponding features in layout data corresponding to the plurality of images; modeling the alignment differences; and adjusting at least one of: a machine setting corresponding to obtaining the plurality of images; or at least one feature of the plurality of features on at least one image of the plurality of images using the modeling.