OVERLAY MEASUREMENT USING MULTIPLE WAVELENGTHS

    公开(公告)号:US20200381312A1

    公开(公告)日:2020-12-03

    申请号:US16092559

    申请日:2018-09-03

    IPC分类号: H01L21/66 H01L21/67 G01N21/31

    摘要: A method of determining overlay (“OVL”) in a pattern in a semiconductor wafer manufacturing process comprises capturing images from a cell in a metrology target formed in at least two different layers in the wafer with parts of the target offset in opposing directions with respect to corresponding parts in a different layer. The images may be captured using radiation of multiple different wavelengths, each image including +1 and −1 diffraction patterns. A first and second differential signal may be determined for respective pixels in each image by subtracting opposing pixels from the +1 and −1 diffraction orders for each of the multiple wavelengths. An OVL for the respective pixels may be determined based on analyzing the differential signals from multiple wavelengths simultaneously. Then an OVL for the pattern may be determined as a weighted average of the OVL of the respective pixels.

    Overlay measurement using multiple wavelengths

    公开(公告)号:US11158548B2

    公开(公告)日:2021-10-26

    申请号:US16092559

    申请日:2018-09-03

    摘要: A method of determining overlay (“OVL”) in a pattern in a semiconductor wafer manufacturing process comprises capturing images from a cell in a metrology target formed in at least two different layers in the wafer with parts of the target offset in opposing directions with respect to corresponding parts in a different layer. The images may be captured using radiation of multiple different wavelengths, each image including +1 and −1 diffraction patterns. A first and second differential signal may be determined for respective pixels in each image by subtracting opposing pixels from the +1 and −1 diffraction orders for each of the multiple wavelengths. An OVL for the respective pixels may be determined based on analyzing the differential signals from multiple wavelengths simultaneously. Then an OVL for the pattern may be determined as a weighted average of the OVL of the respective pixels.

    METHODS OF ANALYZING AND UTILIZING LANDSCAPES TO REDUCE OR ELIMINATE INACCURACY IN OVERLAY OPTICAL METROLOGY
    4.
    发明申请
    METHODS OF ANALYZING AND UTILIZING LANDSCAPES TO REDUCE OR ELIMINATE INACCURACY IN OVERLAY OPTICAL METROLOGY 审中-公开
    分析和利用景观以减少或消除在重叠光学计量学中不精确的方法

    公开(公告)号:US20160313658A1

    公开(公告)日:2016-10-27

    申请号:US15198902

    申请日:2016-06-30

    IPC分类号: G03F9/00

    摘要: Methods are provided for deriving a partially continuous dependency of metrology metric(s) on recipe parameter(s), analyzing the derived dependency, determining a metrology recipe according to the analysis, and conducting metrology measurement(s) according to the determined recipe. The dependency may be analyzed in form of a landscape such as a sensitivity landscape in which regions of low sensitivity and/or points or contours of low or zero inaccuracy are detected, analytically, numerically or experimentally, and used to configure parameters of measurement, hardware and targets to achieve high measurement accuracy. Process variation is analyzed in terms of its effects on the sensitivity landscape, and these effects are used to characterize the process variation further, to optimize the measurements and make the metrology both more robust to inaccuracy sources and more flexible with respect to different targets on the wafer and available measurement conditions.

    摘要翻译: 提供了用于导出计量度量对配方参数的部分连续依赖性的方法,分析衍生依赖性,根据分析确定计量配方,并根据确定的配方进行计量测量。 依赖性可以以景观的形式进行分析,例如灵敏度景观,其中检测到低分辨率或零误差的低灵敏度和/或点或等值线的区域,分析,数字或实验,并用于配置测量参数,硬件 并达到高测量精度。 根据其对灵敏度景观的影响分析过程变化,并且这些效应用于进一步表征过程变化,优化测量结果,使计量学对于不准确性来源更加鲁棒,并且对于不同的目标更灵活 晶圆和可用的测量条件。

    Mitigation of Inaccuracies Related to Grating Asymmetries in Scatterometry Measurements

    公开(公告)号:US20190033726A1

    公开(公告)日:2019-01-31

    申请号:US15753187

    申请日:2017-12-15

    IPC分类号: G03F7/20

    摘要: Scatterometry overlay targets as well as target design and measurement methods are provided, which mitigate the effects of grating asymmetries in diffraction based overlay measurements. Targets comprise additional cells with sub-resolved structures replacing resolved coarse pitch gratings and/or comprise alternating sub-resolved structures with coarse pitch periodicity—to isolate and remove inaccuracies that result from grating asymmetries. Measurement methods utilize orthogonally polarized illumination to isolate the grating asymmetry effects in different measurement directions, with respect to the designed target structures.