There are provided a method of accurately detecting a measurement error of SEM equipment by comparing and aligning a design image with an SEM image, and a method of accurately aligning SEM equipment based on a detected measurement error. The method of detecting a measurement error of SEM equipment includes acquiring SEM images of a measurement target, performing pre-processing on the SEM images and design images corresponding thereto, selecting training SEM images from among the SEM images, performing training by using the training SEM images and training design images and generating a conversion model between the SEM images and the design images, converting the SEM images into conversion design images by using the conversion model, extracting an alignment coordinate value by comparing and aligning the conversion design images with the design images, and determining a measurement error of the SEM equipment based on the alignment coordinate value.

A metrology method for use in determining one or more parameters of a three-dimensional patterned structure, the method including performing a fitting procedure between measured TEM image data of the patterned structure and simulated TEM image data of the patterned structure, determining a measured Lamellae position of at least one measured TEM image in the TEM image data from a best fit condition between the measured and simulated data, and generating output data indicative of the simulated TEM image data corresponding to the best fit condition to thereby enable determination therefrom of the one or more parameters of the structure.

A charged particle beam device includes: a charged particle beam source; an analyzer that analyzes and detects particles including secondary electrons and backscattered charged particles that are emitted from a specimen by irradiating the specimen with a primary charged particle beam emitted from the charged particle beam source; a bias voltage applying unit that applies a bias voltage to the specimen; and an analysis unit that extracts a signal component of the secondary electrons based on a first spectrum obtained by detecting the particles with the analyzer in a state where a first bias voltage is applied to the specimen, and a second spectrum obtained by detecting the particles with the analyzer in a state where a second bias voltage different from the first bias voltage is applied to the specimen.

Methods and apparatuses are disclosed herein for parameter estimation for metrology. An example method at least includes optimizing, using a parameter estimation network, a parameter set to fit a feature in an image based on one or more models of the feature, the parameter set defining the one or more models, and providing metrology data of the feature in the image based on the optimized parameter set.

A method of determining a field of view setting for an inspection tool having a configurable field of view, the method including: obtaining a process margin distribution of features on at least part of a substrate; obtaining a threshold value; identifying, in dependence on the obtained process margin distribution and the threshold value, one or more regions on at least part of the substrate; and determining the field of view setting in dependence on the identified one or more regions.

A data processing device for detecting defects in sample image data generated by a charged particle assessment system, the device comprising: a first processing module configured to receive a sample image datastream from the charged particle assessment system, the sample image datastream comprising an ordered series of data points representing an image of the sample, and to apply a first defect detection test to select a subset of the sample image datastream as first selected data, wherein the first defect detection test is a localised test which is performed in parallel with receipt of the sample image datastream; and a second processing module configured to receive the first selected data and to apply a second defect detection test to select a subset of the first selected data as second selected data.

A method can be used for sensing and processing image data for an object to be imaged. The object is scanned incompletely by virtue of regions (eB) of the object being sensed, where the sensed image regions (eB) alternate with non-sensed image regions (neB) of the object. Image data (rBD) of the non-sensed image regions (neB) are reconstructed on the basis of the sensed image data (eBD) of the sensed image regions (eB). A noise signal (N) of the sensed image data (eBD) of the sensed regions (eB) is ascertained and transferred to the reconstructed image data (rBD) of the non-sensed regions (neB), so that a user obtains a homogeneous visual impression in relation to the noise arising in the overall image data of the object visualized in a resultant overall image (rGB.sub.Inv).

When a high-performance retarding voltage applying power supply cannot be employed in terms of costs or device miniaturization, it is difficult to sufficiently adjust focus in a high acceleration region within a range of changing an applied voltage, and identify a point at which a focus evaluation value is maximum. To address the above problems, a scanning electron microscope is provided including: an objective lens configured to converge an electron beam emitted from an electron source; a current source configured to supply an excitation current to the objective lens; a negative-voltage applying power supply configured to form a decelerating electric field of the electron beam on a sample; a detector configured to detect charged particles generated when the electron beam is emitted to the sample; and a control device configured to calculate a focus evaluation value from an image formed according to an output of the detector. The control device calculates a focus evaluation value when an applied voltage is changed, determines whether to increase or decrease an excitation current according to an increase or a decrease of the focus evaluation value, and supplies the excitation current based on a result of the determination.

Provided is an electron microscope for generating a montage image by acquiring images of a plurality of regions in a montage image capturing region set on a specimen, and by connecting the acquired images. The electron microscope includes a specimen surface height calculating unit that calculates a distribution of specimen surface heights in the montage image capturing region by performing curved surface approximation based on the specimen surface heights determined by performing focus adjustment at a plurality of points set in a region including the montage image capturing region, and an image acquiring unit that acquires the images of the plurality of regions based on the calculated distribution of the specimen surface heights.

A method for electron microscopy comprises: adjusting at least one of an electron beam and an image beam in such a way that off-axial aberrations inflicted on at least one of the electron beam and the image beam are minimized, the adjusting performed by using a beam adjusting component to obtain at least one modified image beam, wherein the adjusting comprises applying both shifting and tilting to at least one of the electron beam and the image beam and wherein the amount of tilting of at least one of the electron beam and the image beam depends on the amount of shifting of at least one of the electron beam and the image beam respectively and wherein the amount of tilting is computed based on at least one of coma and astigmatism introduced as a consequence of the shift.