A multi-electron beam image acquisition apparatus includes a first electrostatic lens and a second electrostatic lens configured to, using one of a table and an approximate expression, dynamically correct the focus position deviation amount deviated from the reference position because of a change of a height position of a surface of a substrate changed along with movement of a stage, and correct one of a rotation change amount and a magnification change amount depending on a focus position deviation amount by interaction; and an image processing circuit configured to, using the one of the table and the approximate expression, correct another of the rotation change amount and the magnification change amount depending on the focus position deviation amount, with respect to a secondary electron image based on a detection signal of multiple secondary electron beams having been detected.

A charged particle beam apparatus with reduced frequency of lens resetting operations and thus with improved throughput. The apparatus includes an electron source configured to generate an electron beam, an objective lens to which coil current is adapted to be applied to converge the electron beam on a sample, a focal position adjustment device configured to adjust the focal position of the electron beam, a detector configured to detect electrons from the sample, a display unit configured to display an image of the sample in accordance with a signal from the detector, a storage unit configured to store information on the hysteresis characteristics of the objective lens, and an estimation unit configured to estimate a magnetic field generated by the objective lens on the basis of the coil current, the amount of adjustment of the focal position by the focal position adjustment device, and the information on the hysteresis characteristics.

Disclosed are methods for sensing conditions of an electron microscope system and/or a specimen analyzed thereby. Also disclosed are sensor systems and electron microscope systems able to sense system conditions, and/or conditions of the specimen being analyzed by such systems. In one embodiment, a sparse dataset can be acquired from a random sub-sampling of the specimen by an electron beam probe of the electron microscope system. Instrument parameters, specimen characteristics, or both can be estimated from the sparse dataset.

A multiple-electron-beam irradiation apparatus includes a first electrostatic lens, configured using the substrate used as a bias electrode by being applied with a negative potential, a control electrode to which a control potential is applied and a ground electrode to which a ground potential is applied, configured to provide dynamic focusing of the multiple electron beams onto the substrate, in accordance with change of the height position of the surface of the substrate, by generating an electrostatic field, wherein the control electrode is disposed on an upstream side of a maximum magnetic field of the lens magnetic field of the first electromagnetic lens with respect to a direction of a trajectory central axis of the multiple electron beams, and a ground electrode is disposed on an upstream side of the control electrode with respect to the direction of the trajectory central axis.

The present disclosure provides a charged particle optical device for a charged particle system. The device projects an array of charged particle beams towards a sample. The device comprises a control lens array to control a parameter of the array of beams; and an objective lens array to project the array of beams onto the sample, the objective lens array being down beam of the control lens. The objective lens array comprises: an upper electrode; and a lower electrode arrangement that comprises an up-beam electrode and a down-beam electrode. The device is configured to apply an upper potential to the upper electrode, an up-beam potential to the up-beam electrode and a down-beam potential to the down-beam electrode. The potentials are controlled to control the landing energy of the beams on the sample and. to maintain focus of the beams on the sample at the landing energies.

An array of localized auto-focus sensors provides direct measurement of the working distance between each microscope column in the array and the substrate being imaged below. The auto-focus sensors measure the working distance between each column and the imaging substrate as it passes over a point on the substrate to be imaged. The working distance measurement from the sensors is input into a control system, which in turn outputs the required working distance adjustment to the microscope column. The control system independently adjusts microscope working distance and/or physical distance of an individual microscope column in a multi-column microscope based on auto-focus sensor input. The individual microscope columns in the multi-column microscope can also be used as the auto-focus sensor itself.

A charged particle evaluation system that may include a column that includes an opening; an illumination unit that is configured to scan an area of a sample with an electron beam that passes through the opening; and an optical auto-focus unit that is configured to (i) illuminate the sample with an optical beam that is proximate to the electron beam, during the scan of the area with the electron beam; (ii) receive a reflected optical beam from the sample, (iii) determine a focus status of the electron beam, and (iv) participate in a compensating of an electron beam misfocus.

A method for operating a particle beam microscopy system includes recording a first particle-microscopic image at a given first focus and varying the excitations of the first deflection device within a given first range. The method also includes changing the focus to a second focus, and determining a second range of excitations of the first deflection device on the basis of the first range, the first excitation, the second excitation and a machine parameter determined in advance. The method further includes recording a second particle-microscopic image at the second focus and varying the excitations of the first deflection device within the determined second range. The second range of excitations is determined so that a region of the object represented in the second particle-microscopic image was also represented in the first particle-microscopic image.

The present disclosure provides a machine vision-based automatic focusing and automatic centering method and system, which belongs to the technical field of machine vision-based automatic control. An object stage is controlled to move in an imaging distance range of an electron microscope, and images scanned by the electron microscope when the object stage is at different imaging distances are acquired. The image definition of an object stage image is calculated according to a gray-scale value of each pixel in the object stage image, the imaging position when an image definition value is the maximum is determined, and the object stage is controlled to move to the position, so as to realize machine vision-based accurate focusing. After the accurate focusing is completed, the images that can clearly reflect the arrangement relationship between an indenter and a sample on the object stage are acquired by the electron microscope, and a midline of an indenter area and a midline of a sample area are aligned, so as to realize machine vision-based accurate centering, which avoids the problems of low efficiency and poor accuracy in manual focusing and centering, and improves the focusing and centering efficiency.

Disclosed is a solution for quickly specifying an optical condition of a wafer to be inspected, and in particular, accelerating optical condition setting after obtaining a customer wafer. An inspection apparatus automatic adjustment system according to the present invention includes an analysis-condition-setting interface that inputs analysis conditions; an analysis-execution unit that performs analysis; an inspection-device model and model DB used for analysis; an analysis-result DB that stores analysis results; an observation-condition setting interface that inputs a wafer pattern, a focus point, an optimization index, and a priority; a wafer-pattern search unit that searches for a wafer pattern similar to the input wafer pattern; an optical-condition-extraction unit that extracts, from the analysis result DB, the optimum optical condition for the similar wafer pattern and the focus point; and an optical-condition-setting unit that generates a control signal corresponding to the optical condition and transmits the control signal to the inspection apparatus.