Abstract: A method for classification includes receiving an image of an area of a semiconductor wafer on which a pattern has been formed, the area containing an image location of interest, and receiving computer-aided design (CAD) data relating to the pattern comprising a CAD location of interest corresponding to the image location of interest. At least one value for one or more attributes of the image location of interest is computed based on a context of the CAD location of interest with respect to the CAD data.

Abstract: A method includes irradiating a surface of a sample, which is made-up of multiple types of materials, with a beam of primary electrons. Emitted electrons emitted from the irradiated sample are detected using multiple detectors that are positioned at respective different positions relative to the sample, so as to produce respective detector outputs. Calibration factors are computed to compensate for variations in emitted electron yield among the types of the materials, by identifying, for each material type, one or more horizontal regions on the surface that are made-up of the material type, and computing a calibration factor for the material type based on at least one of the detector outputs at the identified horizontal regions. The calibration factors are applied to the detector outputs. A three-dimensional topographical model of the surface is calculated based on the detector outputs to which the calibration factors are applied.

Abstract: A system, method and computer readable medium for reticle evaluation, the method includes: (i) obtaining, during an imaging process, multiple images of the reticle under different polarization and optionally interferometric conditions; and (ii) generating an output aerial image in response to (i) the multiple images and (ii) differences between the imaging process and an exposure process; wherein during the exposure process an image of the reticle is projected onto a wafer.

Abstract: A method, system and a computer program product for evaluating an evaluated pattern of a mask, the method includes: receiving multiple moments that represent an image of the evaluated pattern; wherein a size of information required for representing the multiple moments is substantially smaller than a size of pixel information that form the image of the evaluated pattern; and processing the multiple moments in order to determine at least one shape parameter of the evaluated pattern.

Abstract: A method, system and a computer program product for evaluating an evaluated pattern of a mask, the method includes: receiving multiple moments that represent an image of the evaluated pattern; wherein a size of information required for representing the multiple moments is substantially smaller than a size of pixel information that form the image of the evaluated pattern; and processing the multiple moments in order to determine at least one shape parameter of the evaluated pattern.

Abstract: A system, method and computer readable medium for reticle evaluation, the method includes: (i) obtaining, during an imaging process, multiple images of the reticle under different polarization and optionally interferometric conditions; and (ii) generating an output aerial image in response to (i) the multiple images and (ii) differences between the imaging process and an exposure process; wherein during the exposure process an image of the reticle is projected onto a wafer.

Abstract: Simulated aerial images for an optical system are made by forming a reference aerial image of a first mask used in connection with the optical system, and then capturing and processing the reference aerial image to generate a set of expansion functions representative of the optical system. The expansion functions account for aberrations and misalignment of the optical system, as well as any aberrations or other defects of a camera therein. The expansion functions are then used to compute simulated aerial images of other masks projected by the optical system. Thus, the expansion functions implicitly represent a calibration of the optical system for purposes of aerial image simulation, obviating the need for direct measurement of the actual aberrations and misalignment. Hence, a simulated aerial image of a second mask for the optical system can be computed by applying the expansion functions to a design of the second mask.

Abstract: A method for generating a simulated aerial image includes forming a reference aerial image of a first mask using an optical system, and capturing and processing the reference aerial image so as to generate a set of expansion functions representative of the optical system. The simulated aerial image of a second mask is then computed by applying the expansion functions to a design of the second mask.

Abstract: A circuit having a hybrid to convert a bi-directional signal into an input signal and an output signal A signal subtractor to receive the input signal and subtract therefrom an estimated echo signal produced by an echo estimation unit which may derive the estimated echo signal from the output signal.