GENERATING AN ALIGNMENT SIGNAL BASED ON LOCAL ALIGNMENT MARK DISTORTIONS

    公开(公告)号:US20230176494A1

    公开(公告)日:2023-06-08

    申请号:US17922922

    申请日:2021-04-22

    CPC classification number: G03F9/7088 G03F9/7092 G03F9/7049 G03F7/70633

    Abstract: A method for generating an alignment signal that includes detecting local dimensional distortions of an alignment mark and generating the alignment signal based on the alignment mark. The alignment signal is weighted based on the local dimensional distortions of the alignment mark. Detecting the local dimensional distortions can include irradiating the alignment mark with radiation, the alignment mark including a geometric feature, and detecting one or more phase and/or amplitude shifts in reflected radiation from the geometric feature. The one or more phase and/or amplitude shifts correspond to the local dimensional distortions of the geometric feature. A parameter of the radiation, an alignment inspection location within the geometric feature, an alignment inspection location on a layer of a structure, and/or a radiation beam trajectory across the geometric feature may be determined based on the one or more detected phase and/or amplitude shifts.

    NOISE CORRECTION FOR ALIGNMENT SIGNAL

    公开(公告)号:US20220066334A1

    公开(公告)日:2022-03-03

    申请号:US17415711

    申请日:2019-12-12

    Abstract: A method of applying a measurement correction includes determining an orthogonal subspace used to characterize the measurement as a plot of data. A first axis of the orthogonal subspace corresponds to constructive interference output from an interferometer of the metrology system plus a first error variable and a second axis of the orthogonal subspace corresponds to destructive interference output from the interferometer of the metrology system plus a second error variable. The method also includes determining a slope of the plot of data and determining a fitted line to the plot of data in the orthogonal subspace based on the slope.

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