Notches or chevrons with known angles relative to each other are formed on a surface of the sample, where each branch of a chevron appears in a cross-sectional face of the sample as a distinct structure. Therefore, when imaging the cross-section face during the cross-sectioning operation, the distance between the identified structures allows unique identification of the position of the cross-section plane along the Z axis. Then a direct measurement of the actual position of each slice can be calculated, allowing for dynamic repositioning to account for drift in the plane of the sample and also dynamic adjustment of the forward advancement rate of the FIB to account for variations in the sample, microscope, microscope environment, etc. that contributes to drift. An additional result of this approach is the ability to dynamically calculate the actual thickness of each acquired slice as it is acquired.

Notches or chevrons with known angles relative to each other are formed on a surface of the sample, where each branch of a chevron appears in a cross-sectional face of the sample as a distinct structure. Therefore, when imaging the cross-section face during the cross-sectioning operation, the distance between the identified structures allows unique identification of the position of the cross-section plane along the Z axis. Then a direct measurement of the actual position of each slice can be calculated, allowing for dynamic repositioning to account for drift in the plane of the sample and also dynamic adjustment of the forward advancement rate of the FIB to account for variations in the sample, microscope, microscope environment, etc. that contributes to drift. An additional result of this approach is the ability to dynamically calculate the actual thickness of each acquired slice as it is acquired.

Generally, the present disclosure provides a method and system for improving imaging efficiency for CPB systems while maintaining or improving imaging accuracy over prior CPB systems. A large field of view image of a sample is acquired at a low resolution and thus, at high speed. The low resolution level is selected to be sufficient for an operator to visually identify structures or areas of interest on the low resolution image. The operator can select one or more small areas of arbitrary shape and size on the low resolution image, referred to as an exact region of interest (XROI). The outline of the XROI is mapped to an x-y coordinate system of the image, and the CPB system is then controlled to acquire a high resolution image of only the XROI identified on the low resolution image. For 3D imaging, once the XROI is identified, each section of the sample can be iteratively imaged in the previously described manner, with the operator having the option to redefine the XROI later.

A method and apparatus for imaging a specimen using a scanning-type microscope, by irradiating a specimen with a beam of radiation using a scanning motion, and detecting a flux of radiation emanating from the specimen in response to the irradiation, in the first sampling session {S.sub.1} of a set {S.sub.n}, gathering data from a first collection of sparsely distributed sampling points {P.sub.1} of set {P.sub.n}. A mathematical registration correction is made to compensate for drift mismatches between different members of the set {P.sub.n}, and an image of the specimen is assembled using the set {P.sub.n} as input to an integrative mathematical reconstruction procedure.

A method for operating a multi-beam particle microscope in an inspection mode of operation and an associated multi-beam particle microscope are disclosed, wherein a detection unit comprises an image generation detection region with fixedly assigned detection channels and an adjustment detection region with additional detection channels. The fixedly assigned detection channels and the additional detection channels are in the same detection plane. Based on signals obtained via the additional detection channels, it is possible to correct an incidence position of the secondary beams on the detection unit in real time, to be precise independently of the specific structure of the detection unit.

Linear fiducials with known angles relative to each other are formed such that their structures appear in a cross-sectional face of the sample as a distinct structure. Therefore, when imaging the cross-section face during the cross-sectioning operation, the distance between the identified structures allows unique identification of the position of the cross-section plane along the Z axis. Then a direct measurement of the actual position of each slice can be calculated, allowing for dynamic repositioning to account for drift in the plane of the sample and also dynamic adjustment of the forward advancement rate of the FIB to account for variations in the sample, microscope, microscope environment, etc. that contributes to drift. An additional result of this approach is the ability to dynamically calculate the actual thickness of each acquired slice as it is acquired.

A scanning electron microscope (SEM) with a swing objective lens (SOL) reduces the off-aberrations to enhance the image resolution, and extends the e-beam scanning angle. The scanning electron microscope comprises a charged particle source, an accelerating electrode, and a swing objective lens system including a pre-deflection unit, a swing deflection unit and an objective lens, all of them are rotationally symmetric with respect to an optical axis. The upper inner-face of the swing deflection unit is tilted an angle to the outer of the SEM and its lower inner-face is parallel to the optical axis. A distribution for a first and second focusing field of the swing objective lens is provided to limit the off-aberrations and can be performed by a single swing deflection unit. Preferably, the two focusing fields are overlapped by each other at least 80 percent.

A structure for grounding an extreme ultraviolet mask (EUV mask) is provided to discharge the EUV mask during the inspection by an electron beam inspection tool. The structure for grounding an EUV mask includes at least one grounding pin to contact conductive areas on the EUV mask, wherein the EUV mask may have further conductive layer on sidewalls or/and back side. The inspection quality of the EUV mask is enhanced by using the electron beam inspection system because the accumulated charging on the EUV mask is grounded. The reflective surface of the EUV mask on a continuously moving stage is scanned by using the electron beam simultaneously. The moving direction of the stage is perpendicular to the scanning direction of the electron beam.

A structure for discharging an extreme ultraviolet mask (EUV mask) is provided to discharge the EUV mask during the inspection by an electron beam inspection tool. The structure for discharging an EUV mask includes at least one grounding pin to contact conductive areas on the EUV mask, wherein the EUV mask may have further conductive layer on sidewalls or/and bottom. The inspection quality of the EUV mask is enhanced by using the electron beam inspection system because the accumulated charging on the EUU mask is grounded.

A structure for discharging an extreme ultraviolet mask (EUV mask) is provided to discharge the EUV mask during the inspection by an electron beam inspection tool. The structure for discharging an EUV mask includes at least one grounding pin to contact conductive areas on the EUV mask, wherein the EUV mask may have further conductive layer on sidewalls or/and bottom. The inspection quality of the EUV mask is enhanced by using the electron beam inspection system because the accumulated charging on the EUU mask is grounded.