An image forming apparatus includes an observation image input section in which a plurality of observation images is input, an emphasis information input section that inputs information to be emphasized, a storage section that defines a plurality of conversion functions that converts the plurality of observation images into a converted image on the basis of a function for conversion and takes, as a parameter, a gradation value of each pixel in the plurality of observation images and a plurality of emphasis functions that takes, as a parameter, a gradation value of each pixel in the conversion functions, an image calculation section that calculates an image in which information to be emphasized is emphasized on the basis of the plurality of input observation images, the input information of the information to be emphasized, the conversion functions, and the emphasis functions, and an emphasized image output section that outputs the emphasized image.

The present application relates to an apparatus for determining a position of at least one element on a photolithographic mask, said apparatus comprising: (a) at least one scanning particle microscope comprising a first reference object, wherein the first reference object is disposed on the scanning particle microscope in such a way that the scanning particle microscope can be used to determine a relative position of the at least one element on the photolithographic mask relative to the first reference object; and (b) at least one distance measuring device, which is embodied to determine a distance between the first reference object and a second reference object, wherein there is a relationship between the second reference object and the photolithographic mask.

An object of the invention relates to the fact that the alignment of the sample stage and the optical image can be adjusted with high accuracy, good operability, and high throughput by utilizing a low magnification optical image and a high magnification optical image. The invention relates to the fact that an alignment adjustment by a sample table alignment can be performed using a first processed optical image obtained by enlarging or reducing or changing a visual field of the optical image of the sample table holding the sample by digital processing, and that an alignment adjustment by an alignment point designation can be performed using a second processed optical image different from the first processed optical image. According to the invention, it is possible to adjust the alignment of the sample stage and the optical image with reference to the outer shape of the sample table and the feature points on the sample without taking out the sample table holding the sample from the sample chamber.

The scanning charged particle beam microscope according to the present application is characterized in that, in acquiring an image of the FOV (field of view), interspaced beam irradiation points are set, and then, a deflector is controlled so that a charged particle beam scan is performed faster when the charged particle beam irradiates a position on the sample between each of the irradiation points than when the charged particle beam irradiates a position on the sample corresponding to each of the irradiation points (a position on the sample corresponding to each pixel detecting a signal). This allows the effects from a micro-domain electrification occurring within the FOV to be mitigated or controlled.

Provided is a measurement method for measuring, in an electron microscope including a segmented detector having a detection plane segmented into a plurality of detection regions, a direction of each of the plurality of detection regions in a scanning transmission electron microscope (STEM) image, the measurement method including: shifting an electron beam EB incident on a sample S under a state where the detection plane is conjugate to a plane shifted from a diffraction plane to shift the electron beam EB on the detection plane, and measuring a shift direction of the electron beam EB on the detection plane with the segmented detector; and obtaining the direction of each of the plurality of detection regions in the STEM image from the shift direction.

A method for calibrating a scanning charged particle microscope, such as a scanning electron microscope (SEM), is provided. The method includes dividing a wafer into a plurality of regions; preparing, on each of the plurality of regions, a pattern including a first periodic structure interleaved with a second periodic structure, the first and second periodic structures having an induced offset; determining an actual pitch the first and second periodic structures and thereby determining actual induced offset on each of the plurality of regions; selecting a plurality of regions from among the plurality of regions; measuring, by the SEM, a pitch of first and second periodic structures on each of the plurality of regions; and performing linearity calibration on the SEM based on the determining and the measuring.

A reference sample (41) has a step/terrace structure made of monocrystalline SiC and a surface of each terrace has first or second stack orientation. In the reference sample (41), contrast as difference in lightness and darkness between an image of a terrace with a surface directly under which the first stack orientation lies and an image of a terrace with a surface directly under which the second stack orientation lies changes according to an incident electron angle which is an angle that an electron beam emitted from a scanning electron microscope forms with a perpendicular to the terrace surface. Even when a SiC substrate has an off angle (e.g., from 1 to 8), using an inclined support base (20a) capable of correcting the off angle enables sharp contrast that reflects difference between the first and second stack orientations directly under the surface to be obtained irrespective of the off angle.

Embodiments may include methods, systems, and apparatuses for correcting a response function of an electron beam tool. The correcting may include modulating an electron beam parameter having a frequency; emitting an electron beam based on the electron beam parameter towards a specimen, thereby scattering electrons, wherein the electron beam is described by a source wave function having a source phase and a landing angle; detecting a portion of the scattered electrons at an electron detector, thereby yielding electron data including an electron wave function having an electron phase and an electron landing angle; determining, using a processor, a phase delay between the source phase and the electron phase, thereby yielding a latency; and correcting, using the processor, the response function of the electron beam tool using the latency and a difference between the source wave function and the electron wave function.

A method of reducing variability of an error associated with a structure on a substrate in a lithography process is disclosed. The method includes determining, based on one or more images obtained based on a scan of the substrate by a scanning electron microscope (SEM), a first error due to a SEM distortion in the image. The method also includes determining, based on the image, a second error associated with a real error of the structure, where the error associated with the structure includes the first error and the second error. A command is generated by a data processor that enables a modification of the lithography process and an associated reduction of the variability of the error based on reducing any of the first error or the second error.

The methods and systems disclosed here leverage currently available reliable top down imaging techniques used by SEMs and use computational methods to synthesize accurate 3D profiles of features of high aspect ratio structures in a device. Radial cross-sectional profiles obtained from different locations along the lateral direction at different heights/depths are stitched together to create one composite 3D profile of the HAR feature.