DARKFIELD IMAGING OF GRATING TARGET STRUCTURES FOR OVERLAY MEASUREMENT

    公开(公告)号:US20210072021A1

    公开(公告)日:2021-03-11

    申请号:US16996328

    申请日:2020-08-18

    IPC分类号: G01B11/27 G06T7/00

    摘要: A metrology system may include an illumination sub-system to illuminate a metrology target on a sample with illumination having a symmetric off-axis illumination profile, where the symmetric off-axis illumination profile is symmetric along one or more measurement directions, and where the illumination sub-system provides illumination from opposing angles in the symmetric off-axis illumination profile at least one of simultaneously or sequentially. The metrology target may include a first periodic structure on a first layer of the sample and a second periodic structure on a second layer of the sample. The metrology system may further include an imaging sub-system to generate images of the metrology target formed using two non-zero diffraction orders from each point of the symmetric off-axis illumination profile. The metrology subsystem may further determine an overlay error indicative of alignment between the first layer and the second layer based on the one or more images.

    Fourier filters and wafer inspection systems
    4.
    发明授权
    Fourier filters and wafer inspection systems 有权
    傅立叶滤波器和晶圆检查系统

    公开(公告)号:US07345754B1

    公开(公告)日:2008-03-18

    申请号:US11228584

    申请日:2005-09-16

    IPC分类号: G01N21/00 G02B27/46

    摘要: Fourier filters and wafer inspection systems are provided. One embodiment relates to a one-dimensional Fourier filter configured to be included in a bright field inspection system such that the bright field inspection system can be used for broadband dark field inspection of a wafer. The Fourier filter includes an asymmetric illumination aperture configured to be positioned in an illumination path of the inspection system. The Fourier filter also includes an asymmetric imaging aperture complementary to the illumination aperture. The imaging aperture is configured to be positioned in a light collection path of the inspection system such that the imaging aperture blocks light reflected and diffracted from structures on the wafer and allows light scattered from defects on the wafer to pass through the imaging aperture.

    摘要翻译: 提供傅立叶滤波器和晶片检测系统。 一个实施例涉及被配置为包括在明场检查系统中的一维傅立叶滤波器,使得明场检查系统可以用于晶片的宽带暗视场检查。 傅里叶滤波器包括被配置为定位在检查系统的照明路径中的非对称照明孔。 傅立叶滤波器还包括与照明孔径互补的非对称成像孔。 成像孔被配置为定位在检查系统的光采集路径中,使得成像孔口阻挡从晶片上的结构反射和衍射的光,并允许从晶片上的缺陷散射的光通过成像孔。

    Systems and methods for providing illumination of a specimen for inspection

    公开(公告)号:US07304731B2

    公开(公告)日:2007-12-04

    申请号:US11219014

    申请日:2005-09-02

    申请人: Andrew V. Hill

    发明人: Andrew V. Hill

    IPC分类号: G01N21/88

    摘要: Systems and methods for providing illumination of a specimen for inspection are provided. One system includes one or more first optical elements configured to illuminate a diffuser with a predetermined pattern of coherent light. The system also includes one or more second optical elements configured to image light exiting the diffuser onto an illumination pupil of the system such that the predetermined pattern is reproduced in the illumination pupil. In addition, the system includes an objective lens configured to focus light from the predetermined pattern in the illumination pupil onto a specimen plane. In one embodiment, the light focused onto the specimen plane is not substantially coherent. In another embodiment, the predetermined pattern is selected based on an illumination mode selected for the inspection of the specimen.

    System and Method for Determining Image Focus by Sampling the Image at Multiple Focal Planes Simultaneously
    6.
    发明申请
    System and Method for Determining Image Focus by Sampling the Image at Multiple Focal Planes Simultaneously 审中-公开
    用于通过在多重焦点平面上采样图像来确定图像聚焦的系统和方法

    公开(公告)号:US20110228070A1

    公开(公告)日:2011-09-22

    申请号:US12941054

    申请日:2010-11-06

    IPC分类号: H04N7/18 H04N5/232

    CPC分类号: H04N5/23248

    摘要: A system and method for maintaining focus in an imaging device; the imaging device having an objective lens with an optical axis, a stage for supporting a specimen, and a controller for controlling the stage-to-objective distance; the system comprising: one or more image sensors placed at a plurality of substantially different axial focal positions, and at least one computing device executing computer-readable instructions stored in its memory and configured to acquire images from each of the image sensors; the method comprising: computing a quantitative image characteristic for each of the images acquired by the computing device, computing an axial stage-to-objective distance correction based on the computed quantitative image characteristics and the plurality of axial focal positions, and causing the controller to adjust the axial stage-to-objective distance according to the computed axial stage-to-objective distance correction.

    摘要翻译: 一种用于在成像装置中保持焦点的系统和方法; 所述成像装置具有带有光轴的物镜,用于支撑样本的台,以及用于控制所述阶段对目标距离的控制器; 所述系统包括:放置在多个基本上不同的轴向焦点位置的一个或多个图像传感器,以及执行存储在其存储器中并被配置为从每个图像传感器获取图像的计算机可读指令的至少一个计算设备; 所述方法包括:计算由所述计算设备获取的每个图像的定量图像特征,基于所计算的定量图像特征和所述多个轴向焦点位置计算轴向阶段到目标距离校正,并且使所述控制器 根据计算的轴向阶段到目标的距离校正来调整轴向阶段到目标的距离。

    Systems and methods for blocking specular reflection and suppressing modulation from periodic features on a specimen
    7.
    发明授权
    Systems and methods for blocking specular reflection and suppressing modulation from periodic features on a specimen 有权
    用于阻挡镜面反射并抑制样品周期特征的调制的系统和方法

    公开(公告)号:US07940384B2

    公开(公告)日:2011-05-10

    申请号:US11957985

    申请日:2007-12-17

    IPC分类号: G01N21/00

    摘要: Systems and methods for blocking specular reflection and suppressing modulation from periodic features on a specimen are provided. One inspection system configured to block specular reflection and suppress modulation in an image of a specimen includes an illumination subsystem configured to illuminate the specimen with a predetermined pattern of spatially incoherent light. The system also includes an optical element configured to block light reflected from periodic features formed on the specimen and at least some light diffracted from the periodic features. The system further includes a detector configured to detect light that passes through the optical element and to generate an image of the specimen in response to the detected light. The optical element blocks specular reflection and at least partially suppresses modulation in the image due to the periodic features. The system also includes a processor configured to detect defects on the specimen using the image.

    摘要翻译: 提供了用于阻挡镜面反射并抑制样本上的周期特征的调制的系统和方法。 配置为阻挡镜面反射并抑制样本图像中的调制的一个检查系统包括被配置为以预定的空间非相干光图案来照射样本的照明子系统。 该系统还包括光学元件,其被配置为阻挡从形成在样本上的周期特征反射的光和从周期特征衍射的至少一些光。 该系统还包括检测器,其被配置为检测通过光学元件的光并且响应于检测到的光而产生样本的图像。 光学元件阻挡镜面反射并且至少部分地抑制由于周期特征导致的图像中的调制。 该系统还包括处理器,其被配置为使用图像检测样本上的缺陷。

    Systems and Method for Simultaneously Inspecting a Specimen with Two Distinct Channels
    8.
    发明申请
    Systems and Method for Simultaneously Inspecting a Specimen with Two Distinct Channels 有权
    同时检测两个不同通道样本的系统和方法

    公开(公告)号:US20090059215A1

    公开(公告)日:2009-03-05

    申请号:US11848516

    申请日:2007-08-31

    IPC分类号: G01N21/88 G02B21/18

    摘要: A system is provided herein for inspecting a specimen. In one embodiment, the system may include a dual-channel microscope, two illuminators, each coupled for illuminating a different channel of the dual-channel microscope and two detectors, each coupled to a different channel of the dual-channel microscope for acquiring images of the specimen. Means are provided for separating the channels of the dual-channel microscope, so that the two detectors can acquire the images of the specimen at substantially the same time. In one embodiment, the channels of the dual-channel microscope may be spectrally separated by configuring the two illuminators, so that they produce light in two substantially non-overlapping spectral ranges. In another embodiment, the channels of the dual-channel microscope may be spatially separated by positioning the two detectors, so that the illumination light do not overlap and the fields of view of the two detectors do not overlap within a field of view of an objective lens included within the system.

    摘要翻译: 本文提供了用于检查样本的系统。 在一个实施例中,系统可以包括双通道显微镜,两个照明器,每个照明器被耦合用于照亮双通道显微镜和两个检测器的不同通道,每个检测器耦合到双通道显微镜的不同通道,用于获取 标本。 提供了用于分离双通道显微镜的通道的装置,使得两个检测器可以在基本上同时获取样本的图像。 在一个实施例中,双通道显微镜的通道可以通过配置两个照明器进行光谱分离,使得它们产生两个基本上非重叠的光谱范围的光。 在另一个实施例中,双通道显微镜的通道可以通过定位两个检测器在空间上分离,使得照明光不重叠,并且两个检测器的视场在目标的视场内不重叠 镜头包含在系统内。

    SYSTEMS AND METHODS FOR BLOCKING SPECULAR REFLECTION AND SUPPRESSING MODULATION FROM PERIODIC FEATURES ON A SPECIMEN
    9.
    发明申请
    SYSTEMS AND METHODS FOR BLOCKING SPECULAR REFLECTION AND SUPPRESSING MODULATION FROM PERIODIC FEATURES ON A SPECIMEN 有权
    用于阻挡样本中的周期特征的波形反射和抑制调制的系统和方法

    公开(公告)号:US20080144034A1

    公开(公告)日:2008-06-19

    申请号:US11957985

    申请日:2007-12-17

    IPC分类号: G01N21/55

    摘要: Systems and methods for blocking specular reflection and suppressing modulation from periodic features on a specimen are provided. One inspection system configured to block specular reflection and suppress modulation in an image of a specimen includes an illumination subsystem configured to illuminate the specimen with a predetermined pattern of spatially incoherent light. The system also includes an optical element configured to block light reflected from periodic features formed on the specimen and at least some light diffracted from the periodic features. The system further includes a detector configured to detect light that passes through the optical element and to generate an image of the specimen in response to the detected light. The optical element blocks specular reflection and at least partially suppresses modulation in the image due to the periodic features. The system also includes a processor configured to detect defects on the specimen using the image.

    摘要翻译: 提供了用于阻挡镜面反射并抑制样本上的周期特征的调制的系统和方法。 配置为阻挡镜面反射并抑制样本图像中的调制的一个检查系统包括被配置为以预定的空间非相干光图案来照射样本的照明子系统。 该系统还包括光学元件,其被配置为阻挡从形成在样本上的周期特征反射的光和从周期特征衍射的至少一些光。 该系统还包括检测器,其被配置为检测通过光学元件的光并且响应于检测到的光而产生样本的图像。 光学元件阻挡镜面反射并且至少部分地抑制由于周期特征导致的图像中的调制。 该系统还包括处理器,其被配置为使用图像检测样本上的缺陷。

    Method for reducing aliasing in TDI based imaging
    10.
    发明授权
    Method for reducing aliasing in TDI based imaging 有权
    降低TDI成像中混叠的方法

    公开(公告)号:US08947521B1

    公开(公告)日:2015-02-03

    申请号:US13569607

    申请日:2012-08-08

    摘要: The invention may be embodied in a time delay integration (TDI) based sensor wafer inspection system that introduces controlled blur into the sampled image to suppress high spectral frequencies and thereby mitigate the occurrence of aliasing in the sampled image. Image blur may be introduced in the scan direction by desynchronizing the image motion (scan rate) from the charge transfer rate within the TDI sensor (sample clock rate). The scan rate may be desynchronized from the TDI sample clock rate by altering the speed of wafer movement, the sample clock rate, or the magnification of the imaging optics. Image blur may be introduced in the cross-scan direction by imparting a small alignment difference between the direction of image motion (image scan direction) and the direction that charges transfer within the TDI sensor (sensor direction).

    摘要翻译: 本发明可以体现在基于时间延迟积分(TDI)的传感器晶片检查系统中,该系统将受控模糊引入采样图像中以抑制高频谱频率,从而减轻采样图像中混叠的出现。 通过从TDI传感器内的电荷传输速率(采样时钟速率)中取消同步图像运动(扫描速率)可以在扫描方向上引入图像模糊。 通过改变晶片移动的速度,采样时钟速率或成像光学器件的放大倍数,扫描速率可以从TDI采样时钟速率去同步。 可以通过在图像运动方向(图像扫描方向)和TDI传感器(传感器方向)内传送的方向之间施加小的对准差来在横扫方向上引入图像模糊。