From a reference waveform 112 and a BSE signal waveform 211 that is extracted from a backscattered electron image and indicates a backscattered electron signal intensity from a pattern along a first direction, a difference waveform indicating a relationship between the backscattered electron signal intensity and a difference between a coordinate of the BSE signal waveform and a coordinate of the reference waveform which have the same backscattered electron signal intensity is generated, and presence or absence of a shielded region 203 that is not irradiated with a primary electron beam on a side wall of the pattern is determined based on the difference waveform. The reference waveform indicates a backscattered electron signal intensity from a reference pattern along the first direction in which the side wall is formed perpendicularly to an upper surface and a bottom surface of the pattern when the reference pattern is scanned with the primary electron beam.

The mark position is measured with a multi-beam with high accuracy. A multi charged particle beam writing method includes forming a multi-beam (30a-30e) in which charged particle beams are arranged with a predetermined pitch, irradiating a mark (M) with beams in an on-beam region while shifting irradiation positions of the charged particle beams by sequentially changing the on-beam region in which beams in a partial region of the multi-beam (30a-30e) are set to ON, the mark (M) being provided at a predetermined position and having a width greater than the predetermined pitch, detecting a reflected charged particle signal from the mark (M), and calculating a position of the mark (M), and adjusting the irradiation positions of the multi-beam based on the calculated position of the mark (M), and writing a pattern.

Methods and systems for imaging a sample with a charged particle microscope comprises after scanning a region of interest (ROI) of a sample with an electron beam and acquiring X-rays emitted from the sample, scanning the ROI with an ion beam and acquiring ion-induced photons emitted from the sample. A spatial distribution of multiple elements in the sample may be determined based on both the acquired X-rays and the acquired ion-induced photons.

An electron optical module for providing an off-axial electron beam with a tunable coma, according to the present disclosure includes a structure positioned downstream of an electron source and an electron lens assembly positioned between the structure and the electron source. The structure generates a decelerating electric field, and is positioned to prevent the passage of electrons along the optical axis of the electron lens assembly. The electron optical module further includes a micro-lens that is not positioned on the optical axis of the electron lens assembly and is configured to apply a lensing effect to an off-axial election beam. Aberrations applied to the off-axial electron beam by the micro-lens and the electron lens assembly combine so that a coma of the off-axial beam has a desired value in a downstream plane.

A modular ultra-high vacuum (UHV) electron microscope for investigating a sample, according to the present disclosure includes a UHV chamber configured to reach and maintain an ultra-high vacuum within the UHV chamber, a UHV stage to hold the sample being investigated, a charged particle source configured to emit an electron beam toward the sample, and an optical column configured to direct the plurality of electrons to be incident on the sample. The modular UHV electron microscopes further include a carousel vacuum bay configured to reach and maintain an UHV independently of the UHV chamber, and which is connected to the UHV chamber via a port and contains at least one device manipulator. Each of the device manipulators comprise an attachment site for a microscope device, and are configured to, selectively translate attached microscope devices between the carousel vacuum bay and the UHV chamber via the valve.

A modular ultra-high vacuum (UHV) electron microscope for investigating a sample, according to the present disclosure includes a UHV chamber configured to reach and maintain an ultra-high vacuum within the UHV chamber, a UHV stage to hold the sample being investigated, a charged particle source configured to emit an electron beam toward the sample, and an optical column configured to direct the plurality of electrons to be incident on the sample. The modular UHV electron microscopes further include a carousel vacuum bay configured to reach and maintain an UHV independently of the UHV chamber, and which is connected to the UHV chamber via a port and contains at least one device manipulator. Each of the device manipulators comprise an attachment site for a microscope device, and are configured to, selectively translate attached microscope devices between the carousel vacuum bay and the UHV chamber via the valve.

Methods for drift corrected, fast, low dose, adaptive sample imaging with a charged particle microscopy system include scanning a surface region of a sample with a charged particle beam to obtain a first image of the surface region with a first detector modality, and then determining a scan strategy for the surface region. The scan strategy comprises a charged particle beam path, a first beam dwell time associated with at least one region of interest in the first image, the first beam dwell time being sufficient to obtain statistically significant data from a second detector modality, and at least a second beam dwell time associated with other regions of the first image, wherein the first beam dwell time is different than the second beam dwell time. The surface region of the sample is then scanned with the determined scan strategy to obtain data from the first and second detector.

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.

A pattern inspection apparatus includes a secondary electron image acquisition mechanism to include a deflector deflecting multiple primary electron beams and a detector detecting multiple secondary electron beams, and acquire a secondary electron image corresponding to each of the multiple primary electron beams by scanning a target object with a pattern thereon with the multiple primary electron beams by the deflector, and detecting the multiple secondary electron beams from the target object by the detector, a storage device to store individual correction kernels each generated for individually adjusting a secondary electron image corresponding to each primary electron beam concerning a reference pattern to be commensurate with a reference blurred image, and a correction circuit to correct, by correspondingly using the individual correction kernel, the secondary electron image corresponding to each primary electron beam acquired from the inspection target object.

A pattern inspection apparatus includes a secondary electron image acquisition mechanism to include a deflector deflecting multiple primary electron beams and a detector detecting multiple secondary electron beams, and acquire a secondary electron image corresponding to each of the multiple primary electron beams by scanning a target object with a pattern thereon with the multiple primary electron beams by the deflector, and detecting the multiple secondary electron beams from the target object by the detector, a storage device to store individual correction kernels each generated for individually adjusting a secondary electron image corresponding to each primary electron beam concerning a reference pattern to be commensurate with a reference blurred image, and a correction circuit to correct, by correspondingly using the individual correction kernel, the secondary electron image corresponding to each primary electron beam acquired from the inspection target object.