Abstract:
A method for monitoring a first nanometric structure formed by a multiple patterning process, the method may include performing a first plurality of measurements to provide a first plurality of measurement results; wherein the performing of the first plurality of measurements comprises illuminating first plurality of locations of a first sidewall of the first nanometric structure by oblique charged particle beams of different tilt angles; and processing, by a hardware processor, the first plurality of measurement results to determine a first attribute of the first nanometric structure.
Abstract:
A method for image processing includes providing a microscopic image of a structure fabricated on a substrate and computer-aided design (CAD) data used in fabricating the structure. The microscopic image is processed by a computer so as to generate a first directionality map, which includes, for a matrix of points in the microscopic image, respective directionality vectors corresponding to magnitudes and directions of edges at the points irrespective of a sign of the magnitudes. The CAD data are processed by the computer so as to produce a simulated image based on the CAD data and to generate a second directionality map based on the simulated image. The first and second directionality maps are compared by the computer so as to register the microscopic image with the CAD data.
Abstract:
A method for determining overlay between layers of a multilayer structure may include obtaining a given image representing the multilayer structure, obtaining expected images for layers of the multilayer structure, providing a combined expected image of the multilayer structure as a combination of the expected images of said layers, performing registration of the given image against the combined expected image, and providing segmentation of the given image, thereby producing a segmented image, and maps of the layers of said multilayered structure. The method may further include determining overlay between any two selected layers of the multilayer structure by processing the maps of the two selected layers together with the expected images of said two selected layers.
Abstract:
A method for determining overlay between layers of a multilayer structure may include obtaining a given image representing the multilayer structure, obtaining expected images for layers of the multilayer structure, providing a combined expected image of the multilayer structure as a combination of the expected images of said layers, performing registration of the given image against the combined expected image, and providing segmentation of the given image, thereby producing a segmented image, and maps of the layers of said multilayered structure. The method may further include determining overlay between any two selected layers of the multilayer structure by processing the maps of the two selected layers together with the expected images of said two selected layers.
Abstract:
A method for determining overlay between layers of a multilayer structure may include obtaining a given image representing the multilayer structure, obtaining expected images for layers of the multilayer structure, providing a combined expected image of the multilayer structure as a combination of the expected images of said layers, performing registration of the given image against the combined expected image, and providing segmentation of the given image, thereby producing a segmented image, and maps of the layers of said multilayered structure. The method may further include determining overlay between any two selected layers of the multilayer structure by processing the maps of the two selected layers together with the expected images of said two selected layers.
Abstract:
A method for process control of a semiconductor structure fabricated by a series of fabrication steps, the method comprising obtaining an image of the semiconductor structure indicative of at least two individual fabrication steps; wherein the image is generated by scanning the semiconductor structure with a charged particle beam and collecting signals emanating from the semiconductor structure; and processing, by a hardware processor, the image to determining a parameter of the semiconductor structure, wherein processing includes measuring step/s from among the fabrication steps as an individual feature.
Abstract:
A captured image of a pattern and a reference image of the pattern may be received. A contour of interest of the pattern may be identified. One or more measurements of a dimension of the pattern may be determined for each of the reference image and the captured image with respect to the contour of interest of the pattern. A defect associated with the contour of interest may be classified based on the determined one or more measurements of the dimension of the pattern for each of the reference image and the captured image.
Abstract:
An improved technique for determining height difference in patterns provided on semiconductor wafers uses real measurements (e.g., measurements from SEM images) and a height difference determination model. In one version of the model, a measurable variable of the model is expressed in terms of a function of a change in depth of shadow (i.e. relative brightness), wherein the depth of shadow depends on the height difference as well as width difference between two features on a semiconductor wafer. In another version of the model, the measurable variable is expressed in terms of a function of a change of a measured distance between two characteristic points on the real image of a periodic structure with respect to a change in a tilt angle of a scanning electron beam.
Abstract:
A height of a pattern on a semiconductor wafer is determined by comparing a measured image of the pattern with a predicted image of the pattern, as produced by a shadow model. An estimated height of the pattern is provided as an input to the shadow model. The shadow model produces occluding contours that are used to generate predicted images. A set of predicted images are generated, each predicted image being associated with an estimated height. The estimated height corresponding to the predicted image most closely matching with the measured image is used as the height calculated by the shadow model.
Abstract:
A Critical Dimensions Scanning Electron Microscope (CD-SEM) is described that comprises a unit for performing CD-SEM measurements of a semiconductor wafer, a BSE imaging unit for obtaining a Grey Level image (GL) of the wafer, and a unit for GL analysis and for processing the GL analysis results with reference to results of the CD-measurements.