Metrology method and apparatus, computer program and lithographic system

    公开(公告)号:US09869940B2

    公开(公告)日:2018-01-16

    申请号:US15133866

    申请日:2016-04-20

    CPC classification number: G03F7/70633 G01B11/24 G01B11/272

    Abstract: Disclosed are a method, computer program and associated apparatuses for measuring a parameter of a lithographic process. The method comprising the steps of: obtaining first measurements comprising measurements of structural asymmetry relating to a plurality of first structures, each of said plurality of measurements of structural asymmetry corresponding to a different measurement combination of measurement radiation and a value for at least a first parameter; obtaining a plurality of second measurements of target asymmetry relating to a plurality of targets, each of said plurality of measurements of target asymmetry corresponding to one of said different measurement combinations, determining a relationship function describing the relationship between said first measurements and said second measurements, for each of said measurement combinations; determining, from said relationship function, a corrected overlay value, said corrected overlay value being corrected for structural contribution due to structural asymmetry in at least said first structure.

    Inspection Apparatus and Methods, Methods of Manufacturing Devices
    6.
    发明申请
    Inspection Apparatus and Methods, Methods of Manufacturing Devices 有权
    检验装置和方法,制造装置的方法

    公开(公告)号:US20160011523A1

    公开(公告)日:2016-01-14

    申请号:US14794013

    申请日:2015-07-08

    Abstract: Inspection apparatus (100) is used for measuring parameters of targets on a substrate. Coherent radiation follows an illumination path (solid rays) for illuminating target (T). A collection path (dashed rays) collects diffracted radiation from the target and delivers it to a lock-in image detector (112). A reference beam following a reference path (dotted rays). An acousto-optical modulator (108) shifts the optical frequency of the reference beam so that the intensity of radiation at the lock-in detector includes a time-varying component having a characteristic frequency corresponding to a difference between the frequencies of the diffracted radiation and the reference radiation. The lock-in image detector records two-dimensional image information representing both amplitude and phase of the time-varying component. A second reference beam with a different shift (110) follows a second reference path (dot-dash rays). Interference between the two reference beams can be used for intensity normalization.

    Abstract translation: 检查装置(100)用于测量基板上的目标的参数。 相干辐射遵循用于照射目标(T)的照明路径(固体光线)。 收集路径(虚线)从目标物体收集衍射辐射并将其传送到锁定图像检测器(112)。 参考光束遵循参考路径(虚线)。 声光调制器(108)移动参考光束的光频率,使得锁定检测器处的​​辐射强度包括具有与衍射辐射的频率之间的差异相对应的特征频率的时变分量,以及 参考辐射。 锁定图像检测器记录表示时变分量的幅度和相位的二维图像信息。 具有不同偏移(110)的第二参考光束遵循第二参考路径(点划线)。 两个参考光束之间的干涉可用于强度归一化。

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