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.

The disclosure relates to a method of aligning a charged particle beam apparatus, comprising the steps of providing a charged particle beam apparatus in a first alignment state; using an alignment algorithm, by a processing unit, for effecting an alignment transition from said first alignment state towards a second alignment state of said charged particle beam apparatus; and providing data related to said alignment transition to a modification algorithm for modifying said alignment algorithm in order to effect a modified alignment transition.

An image conversion unit includes a selector and a plurality of image converters. Each image converter is formed from an estimator of machine learning type, and estimates, based on an image acquired under a first observation condition and as a reference image, an image which is presumed to be acquired under a second observation condition. When a particular reference image is selected from among a plurality of reference images displayed on a display, a second observation condition corresponding to the selected reference image is set in an observation mechanism as a next observation condition.

In this invention, information of material composition, process conditions and candidates of crystal structure either known or imported from material database is used to determine sample stage tilt angle and working distance (WD). Under these determined tilt angle and WD, the intensity of the electrons emitted at different angles and with different energies is measured using a scanning electron microscope (SEM) system comprising: a use of materials database containing materials composition, formation process, crystal structure and its electron yield; a sample stage that is able to move, rotate and tilt; an processing section for calculating optimum working distance for an observation from material database and measurement condition; means for acquiring an image of crystal information of a desired area of a sample based on an image obtained from SEM observation.

The disclosed technology relates to a method and apparatus for correctly positioning a probe suitable for scanning probe microscopy (SPM). The probe is positioned relative to the apex region of a needle-shaped sample, such as a sample for atom probe tomography, in order to perform a SPM acquisition of the apex region to obtain an image of the region. In one aspect, the positioning takes place by an iterative process, starting from a position wherein one side plane of the pyramid-shaped SPM probe interacts with the sample tip. By controlled consecutive scans in two orthogonal directions, the SPM probe tip approaches and finally reaches a position wherein a tip area of the probe interacts with the sample tip's apex region.

An electron microscope includes: an optical system including an aberration correction device; and a control unit that controls the aberration correction device, wherein the control unit performs: processing for displaying, on a display unit, an image for designating a direction of aberration in superposition on an aberration pattern representing a state of aberration, processing for specifying the direction of aberration from the image that has been subjected to a rotation operation, and processing for controlling the aberration correction device to cause the aberration correction device to introduce an aberration in the specified direction.

There is provided a method of aberration measurement capable of reducing the effects of image drift. The novel method of aberration measurement is for use in an electron microscope. The method comprises the steps of: acquiring a first image that is a TEM (transmission electron microscope) image of a sample; scanning the illumination angle of an electron beam impinging on the sample and acquiring a second image by multiple exposure of a plurality of TEM images generated at different illumination angles; and calculating aberrations from the first and second images.

A charged particle beam microscope system is operated in a transmission imaging mode. During the operation, the charged particle beam microsystem directs a charged particle beam to the sample to produce images. A time series of beam tilts is applied in a pattern to the charged particle beam directed to the sample to produce a sequence of images. At least some of the images in the sequence of images are captured while the charged particle beam is transitioning between one beam tilt in the time series of beam tilts and a sequentially adjacent beam tilt in the time series of beam tilts. The pattern is configured to induce image changes between the images in the sequence of images that are indicative of optical aberrations in the charged particle beam microscope system.

An aberration computing device (100) includes a fitting section (48) for fitting line profiles of a diffractogram taken in radial directions to a fitting function and finding fitting parameters of the fitting function and a computing section (49) for finding at least one of an amount of defocus and two-fold astigmatism, based on the fitting parameters.

Techniques for yield management in semiconductor inspection systems are described. According to one aspect of the present invention, columns of sensing mechanism in an inspection station are configured with different functions, weights and performances to inspect a sample to significantly reduce the time that would be otherwise needed when all the columns were equally applied.