A process for the preparation and imaging of a sample of rock from an oil and gas reservoir is provided. A sample of reservoir rock may be obtained, such as from a core sample obtained using a core sampling tool inserted in a wellbore extending into an oil and gas reservoir. A photoresist may be deposited on the surface of reservoir rock sample to form a homogenous layer. The photoresist-coated surface of the reservoir rock sample may be imaged using a focused ion beam (FIB). The photoresist protects the pores and other surface features of the rock from damage or implantation by the FIB ion beam and thus minimizes the curtain effect in the resulting images.

According to one embodiment, a multi charged particle beam writing apparatus includes an objective lens adjusting a focus position of multiple beams, a coil correcting astigmatism of the multiple beams, an inspection aperture disposed in a stage and configured to allow one beam of the multiple beams to pass therethrough, a deflector deflecting the multiple beams, a current detector detecting a beam current of each beam of the multiple beams scanned over the inspection aperture in the XY direction and passed through the inspection aperture, and a controller generating a beam image on the basis of the detected beam current, calculating a feature quantity of the beam image, and controlling the objective lens or the coil on the basis of the feature quantity.

A high-quality image is acquired while maintaining an improvement in throughput of image acquisition (measurement (length measurement)) in a charged particle beam system including a charged particle beam device and a computer system configured to control the charged particle beam device. The charged particle beam device includes an objective lens, a sample stage, and a backscattered electron detector that is disposed between the objective lens and the sample stage and that adjusts a focus of a charged particle beam with which a sample is irradiated. The computer system adjusts a value of an electric field on the sample in accordance with a change in a voltage applied to the backscattered electron detector.

A multi-beam charged particle microscope system, having a mirror mode of operation, can be operated to record a stack of images in a mirror imaging mode. The stack of images comprises at least two images of two different settings of at least on multi-aperture element, for example a focus stack, which allows the multi-beam charged particle microscope system to be inspected and recalibrated thoroughly. Related methods computer program products are disclosed.

Electrostatic lenses for focusing a beam of charged particles, and in particular an electron beam, are used especially in the electron guns of electron microscopes or electron-beam lithography apparatuses. The present disclosure improves the possibilities for focusing the particle beam, in particular an electron beam emitted by a cathode. The lens comprises at least one conducting electrode having at least one through-opening for the passage of an electron beam. Different electric fields are set up upstream and downstream of the opening. The passage opening is at least partially closed by a planar or curved thin membrane of semi-conducting material that is transparent to electrons and has a high dielectric permittivity. Structuring the membrane (holes or thickened portions of electrodes deposited on the membrane) makes it possible to correct lens aberration defects.

A method of operating a charged particle microscope comprises: providing settings of a focus, an x-stigmator and an y-stigmator of the charged particle microscope; and then repeatedly performing adjusting the charged particle microscope to the settings, recording an image of an object using the settings, determining a sharpness measure from the recorded image, and changing at least one of the settings of the focus, the x-stigmator and the y-stigmator based on the sharpness measure until a stop criterion is fulfilled. Herein, the determining of the sharpness measure comprises: determining an orientation of an intensity gradient at each of a plurality of locations within one of the recorded image and a processed image generated by processing the recorded image, and determining the sharpness measure based on the plurality of determined orientations.

In the present invention, a charged particle beam device has a charged particle source (1), a first condenser lens (4) arranged downstream from the charged particle source (1), an aperture (5) arranged downstream from the first condenser lens (4), and a second condenser lens (6) arranged downstream from the aperture (5), wherein, when a sample (12) is to be irradiated at a second charged particle beam amount which is greater than a first charged particle beam amount, the first and second condenser lenses are controlled such that a charged particle beam is formed downstream from the aperture (5), and such that the focal point of the second condenser lens does not vary between the first charged particle beam amount and the second charged particle beam amount.

The present invention relates to a lens-less Foucault method wherein a transmission electron microscope objective lens (5) is turned off, an electron beam crossover (11, 13) is matched with a selected area aperture (65), and the focal distance of a first imaging lens (61) can be changed to enable switching between a sample image observation mode and a sample diffraction pattern observation mode, characterized in that a deflector (81) is disposed in a stage following the first imaging lens (61), and conditions for an irradiating optical system (4) can be fixed after conditions for the imaging optical system have been determined. This allows a lens-less Foucault method to be implemented in a common general-use transmission electron microscope with no magnetic shielding lens equipped, without burdening the operator.

A focused ion beam system is offered which can make a focal adjustment without relying on the structure of a sample while suppressing damage to the sample to a minimum. Also, a method of making this focal adjustment is offered. The focused ion beam system has an ion source for producing an ion beam, a lens system for focusing the beam onto the sample, a detector for detecting secondary electrons emanating from the sample, and a controller for controlling the lens system. The controller is operative to provide control such that the sample is irradiated with the ion beam without scanning the beam and that a focus of the ion beam is varied by varying the intensity of the objective lens during the ion beam irradiation. Also, the controller measures the intensity of a signal indicating secondary electrons emanating from the sample while the intensity of the objective lens is being varied. Furthermore, the controller makes a focal adjustment of the ion beam on the basis of the intensity of the objective lens obtained when the measured intensity of the signal indicating secondary electrons is minimal.

The present disclosure proposes an anti-rotation lens and using it as an anti-rotation condenser lens in a multi-beam apparatus with a pre-beamlet-forming mechanism. The anti-rotation condenser lens keeps rotation angles of beamlets unchanged when changing currents thereof, and thereby enabling the pre-beamlet-forming mechanism to cut off electrons not in use as much as possible. In this way, the multi-beam apparatus can observe a sample with high resolution and high throughput, and is competent as a yield management tool to inspect and/or review defects on wafers/masks in semiconductor manufacturing industry.