A semiconductor device is scanned by an electron beam of a scanning electron microscope (SEM). The area includes a three-dimensional (3D) feature having a top opening and a sidewall. The 3D feature is imaged while varying an energy value of the electron beam. The electron beam impinges at a first point within a selected area of the semiconductor device and interacts with the sidewall, wherein the first point is at a distance away from an edge of the top opening. Based on change in a signal representing secondary electron yield at the edge as the energy value of the electron beam is varied during the SEM imaging, it is determined whether the sidewall is occluded from a line-of-sight of the electron beam. A slope of the sidewall may be determined by comparing measured signals with simulated waveforms corresponding to various slopes.

A semiconductor device is scanned by an electron beam of a scanning electron microscope (SEM). The area includes a three-dimensional (3D) feature having a top opening and a sidewall. The 3D feature is imaged while varying an energy value of the electron beam. The electron beam impinges at a first point within a selected area of the semiconductor device and interacts with the sidewall, wherein the first point is at a distance away from an edge of the top opening. Based on change in a signal representing secondary electron yield at the edge as the energy value of the electron beam is varied during the SEM imaging, it is determined whether the sidewall is occluded from a line-of-sight of the electron beam. A slope of the sidewall may be determined by comparing measured signals with simulated waveforms corresponding to various slopes.

In one embodiment, a method includes receiving measured linescan information describing a pattern structure of a feature, applying the received measured linescan information to an inverse linescan model that relates measured linescan information to feature geometry information, and identifying, based at least in part on the applying the received measured linescan model to the inverse linescan model, feature geometry information that describes a feature that would produce a linescan corresponding to the received measured linescan information. The method also includes determining, at least in part using the inverse linescan model, feature edge positions of the identified feature, analyzing the feature edge positions to determine errors in the manufacture of the pattern structure, and controlling a lithography tool based on the analysis of the feature edge positions.

A method is disclosed. The method includes receiving measured linescan information describing a pattern structure of a feature, applying the received measured linescan information to an inverse linescan model that relates measured linescan information to feature geometry information, identifying, based at least in part on the applying the received measured linescan model to the inverse linescan model, feature geometry information that describes a feature that would produce a linescan corresponding to the received measured linescan information, determining, at least in part using the inverse linescan model, feature edge positions of the identified feature, and analyzing the feature edge positions to detect the presence or absence of defects in the pattern structure.

A method, non-transitory computer readable medium and an evaluation system for evaluating an intermediate product related to a three dimensional NAND memory unit. The evaluation system may include an imager and a processing circuit. The imager may be configured to obtain, via an open gap, an electron image of a portion of a structural element that belongs to an intermediate product. The structural element may include a sequence of layers that include a top layer that is followed by alternating nonconductive layers and recessed conductive layers. The imager may include electron optics configured to scan the portion of the structural element with an electron beam that is oblique to a longitudinal axis of the open gap. The processing circuit is configured to evaluate the intermediate product based on the electron image. The open gap (a) exhibits a high aspect ratio, (b) has a width of nanometric scale, and (c) is formed between structural elements of the intermediate product.

The present disclosure relates to a pattern measuring method to appropriately measure a height and a depth of a pattern having a high aspect ratio. The method includes measuring a width between a first pattern and another pattern formed on a wafer; calculating a value regarding an azimuth angle of a signal emitted from the wafer; and calculating height information from a portion between the first pattern and the other pattern to an upper portion of a pattern based on the measured width between the first pattern and the other pattern, the value regarding the azimuth angle, the value regarding an elevation angle, and relationship information thereof.

The present invention proposes a pattern measurement tool characterized by being provided with: a charged-particle beam sub-system having a tilt deflector; and a computer sub-system which is connected to the charged-particle beam sub-system and which is for executing measurement of a pattern on the basis of a signal obtained by said charged-particle beam sub-system, wherein the charged-particle beam sub-system acquires at least two signal profiles by scanning beams having at least two incidence angles, the computer sub-system measures the dimension between one end and the other end of the pattern on the basis of the at least two signal profiles, calculates the difference between the two measurements, and calculates the height of the pattern by inputting the difference value determined by said calculation into a relational formula indicating the relation between the height of the pattern and said difference value.

Provided is a technology for evaluating a property of a pattern formed inside a sample from two-dimensional information of the sample. A pattern evaluation system of the present disclosure includes a computer subsystem that executes a process of evaluating a property of a pattern by reading a program from a memory that stores the program for evaluating the property of the pattern formed inside a sample. The computer subsystem executes a process of acquiring an image of the sample; a process of extracting a signal waveform from the image; a process of calculating a feature amount in a predetermined region of the signal waveform; a process of comparing the feature amount with a reference value of the feature amount; and a process of evaluating the property of the pattern based upon a comparison result in the comparison process.

An apparatus and method for a large-scale high-throughput quantitative characterization and three-dimensional reconstruction of a material structure. The apparatus having a glow discharge sputtering unit, a sample transfer device, a scanning electron microscope unit and a GPU computer workstation. The glow discharge sputtering unit can achieve large size (cm order), nearly flat and fast sample preparation, and controllable achieve layer-by-layer ablation preparation along the depth direction of the sample surface; rapid scanning electron microscopy (SEM) can achieve large-scale and high-throughput acquisition of sample characteristic maps. The sample transfer device is responsible for transferring the sample between the glow discharge sputtering source and the scanning electron microscope in an accurately positioning manner. The GPU computer workstation performs splicing, processing, recognition and quantitative distribution characterization on the acquired sample characteristic maps, and carries out three-dimensional reconstruction of the structure of the sample prepared by layer-by-layer sputtering.

Methods and apparatus for inspecting features on a substrate including exposing at least a portion of the substrate to a first electron beam landing energy to obtain a first image; exposing the at least a portion of the substrate to a second electron beam landing energy to obtain a second image, wherein the second electron beam landing energy is different from the first electron beam landing energy; realigning the first image and the second image to a feature on the substrate; and determining from at least one measurement from the first image associated with the feature and at least one measurement from the second image associated with the feature if the feature is leaning or twisting.