Methods and systems for analysis of wafer scan data

    公开(公告)号:US11688055B2

    公开(公告)日:2023-06-27

    申请号:US17160364

    申请日:2021-01-27

    Abstract: Disclosed is a computerized method for detecting defects on a sample. The method includes: (i) receiving scan data corresponding to a pixel on the sample; (ii) computing a difference vector d based on the scan data and corresponding reference data; (iii) computing a parameter D dependent on t=Γd−(Glinear/∥Γs∥2)Γs, wherein ΓTΓ=K−1 with K being a covariance matrix corresponding to the pixel, s is a predetermined kernel characterizing a defect signal, and Glinear=s·(K−1 d) is a gaussian approximation of a likelihood ratio test expression for distinguishing the defect signal from noise, and wherein D substantially monotonically increases with ∥t∥; and (iv) computing a score q(g, D) indicative of whether the pixel is defective, wherein g is a parameter indicative of a value of Glinear and q(g, D) substantially monotonically increases with g and substantially monotonically decreases with D.

    MODEL-BASED ACOUSTO-OPTIC DEPTH-METROLOGY OF SPECIMENS

    公开(公告)号:US20250116597A1

    公开(公告)日:2025-04-10

    申请号:US18377431

    申请日:2023-10-06

    Abstract: Disclosed herein is a method for non-destructive depth-profiling including projecting a pulsed pump beam into a specimen, projecting a pulsed probe beam thereinto, and sensing light returned therefrom to obtain a measured signal. Each probe pulse is configured to undergo Brillouin scattering off a primary acoustic pulse induced by the directly preceding pump pulse, so as to be scattered there off at a respective depth within the specimen. The method further includes executing an optimization algorithm configured to receive as inputs the measured signal, and/or a processed signal obtained therefrom, and output values of structural parameter(s) characterizing the specimen through minimization of a cost function indicative of a difference between the measured signal and a simulated signal obtained using a forward model simulating the scattering of a pulsed probe beam off at least the primary acoustic pulses.

    SCANNING ELECTRON MICROSCOPY-BASED TOMOGRAPHY OF SPECIMENS

    公开(公告)号:US20240404784A1

    公开(公告)日:2024-12-05

    申请号:US18203034

    申请日:2023-05-29

    Abstract: Disclosed herein is a system for non-destructive tomography of specimens. The system includes a scanning electron microscope (SEM) and a processor(s). The SEM is configured to obtain a sinogram of a tested specimen, parameterized by a vector {right arrow over (s)}, by projecting e-beams on the tested specimen, at each of a plurality of projection directions and offsets, and. for each e-beam, measuring a respective intensity of electrons returned from the tested specimen, The processor(s) is configured to obtain a tomographic map, pertaining to the tested specimen, by determining values indicative of components of a vector {right arrow over (t)} defined by an equation W{right arrow over (t)}={right arrow over (s)}. W is a matrix with components wij specifying a contribution of a j-th voxel in a nominal specimen to an i-th element of a nominal sinogram of the nominal specimen. The matrix W accounts for e-beam expansion and attenuation with depth within the nominal specimen.

    Die-to-multi-die wafer inspection

    公开(公告)号:US11803961B2

    公开(公告)日:2023-10-31

    申请号:US17495493

    申请日:2021-10-06

    CPC classification number: G06T7/001 G01N21/9501 G01N21/95607 G06T2207/30148

    Abstract: Disclosed herein is s computer-based method for obtaining and analyzing multi-die scan data of a patterned wafer. The method includes sequentially implementing an operation of scanning a respective plurality of sets of slices on a wafer, and, per each slice segment in a multiplicity of slice segments in the plurality of sets of slices, an operation of performing die-to-multi-die (D2MD) analysis of scan data of the slice segment in order to detect defects in the slice segment. Each set of slices may constitute a subset of the totality of slices on the respective die-column. Sets scanned in a same implementation are analogous to one another, thereby facilitating—in the die-to-multi-die analysis of scan data of a slice segment—taking into account, as reference, scan data of areas on other die-columns, which were scanned in the same implementation.

    Hybrid scanning electron microscopy and acousto-optic based metrology

    公开(公告)号:US12278085B2

    公开(公告)日:2025-04-15

    申请号:US17714908

    申请日:2022-04-06

    Abstract: Disclosed herein is a method for non-destructive hybrid acousto-optic and scanning electron microscopy-based metrology. The method includes: (i) obtaining acousto-optic and scanning electron microscopy measurement data of an inspected structure on a sample; (ii) processing the measurement data to extract values of key measurement parameters corresponding to the acousto-optic measurement data and the scanning electron microscopy measurement data, respectively; and (iii) obtaining estimated values of one or more structural parameters of the inspected structure by inputting the extracted values into an algorithm, which is configured to jointly process the extracted values to output estimated values of the one or more structural parameters.

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