公开(公告)号：US10107621B2

公开(公告)日：2018-10-23

申请号：US13766598

申请日：2013-02-13

申请人： Nanometrics Incorporated

发明人： Nigel P. Smith

IPC分类号： G01B11/14 ,  G01B11/26 ,  G03F7/20

摘要： An image based overlay measurement is performed using an overlay target that includes shifted overlying gratings. The overlay target is imaged and an asymmetry is measured in the image of the overlaid gratings. The asymmetry is used to determine the overlay error. For each measurement direction, the overlay target may include two or more overlay measurement pads with different offsets between the top and bottom gratings. The measured asymmetries and offsets in the overlay measurement pads may be used to determine the overlay error, e.g., using self-calibration. The pitch and critical dimensions of the overlay target may be optimized to produce a greatest change of symmetry with overlay error for a numerical aperture and wavelength of light used by the image based metrology device.

公开(公告)号：US20130208279A1

公开(公告)日：2013-08-15

申请号：US13766598

申请日：2013-02-13

申请人： Nanometrics Incorporated

发明人： Nigel P. Smith

IPC分类号： G01B11/26

CPC分类号： G01B11/26 ,  G03F7/70633

摘要： An image based overlay measurement is performed using an overlay target that includes shifted overlying gratings. The overlay target is imaged and an asymmetry is measured in the image of the overlaid gratings. The asymmetry is used to determine the overlay error. For each measurement direction, the overlay target may include two or more overlay measurement pads with different offsets between the top and bottom gratings. The measured asymmetries and offsets in the overlay measurement pads may be used to determine the overlay error, e.g., using self-calibration. The pitch and critical dimensions of the overlay target may be optimized to produce a greatest change of symmetry with overlay error for a numerical aperture and wavelength of light used by the image based metrology device.

摘要翻译： 使用包括移动的重叠光栅的覆盖目标来执行基于图像的覆盖测量。 覆盖目标被成像，并且在覆盖的光栅的图像中测量不对称性。 不对称性用于确定覆盖错误。 对于每个测量方向，覆盖目标可以包括在顶部和底部光栅之间具有不同偏移的两个或更多个覆盖测量焊盘。 覆盖测量垫中测量的不对称性和偏移量可用于确定覆盖误差，例如使用自校准。 覆盖目标的间距和临界尺寸可以被优化，以产生最大的对称变化，其具有用于数字孔径和由基于图像的计量装置使用的光的波长的重叠误差。

公开(公告)号：US20180156597A1

公开(公告)日：2018-06-07

申请号：US15388794

申请日：2016-12-22

申请人： Nanometrics Incorporated

发明人： Nigel P. Smith ,  George Andrew Antonelli

IPC分类号： G01B9/02

CPC分类号： G01B9/02043 ,  G01B9/02007 ,  G01B9/02027 ,  G01B9/02035 ,  G01B9/02067 ,  G01B9/02072 ,  G01B9/02084 ,  G01B9/0209 ,  G01B2210/56 ,  G01B2290/50 ,  G01B2290/65 ,  G01B2290/70 ,  G01N21/21 ,  G01N21/45 ,  G01N21/956 ,  G01N2021/95676 ,  G02B21/0016 ,  G02B21/0092 ,  H01L22/12

摘要： A white light interferometric metrology device operates in the image plane and objective pupil plane. The interferometric metrology device extracts the electric field with complex parameters and that is a function of azimuth angle, angle of incidence and wavelength from interferometric data obtained from the pupil plane. Characteristics of the sample are determined using the electric field based on an electric field model of the azimuth angle, the angle of incidence and the wavelength that is specific for a zero diffraction order. A center of the pupil in the pupil plane may be determined based on a Fourier transform of the interferometric data at each new measurement and used to convert each pixel from the camera imaging the objective pupil plane into a unique set of angle of incidence and azimuth angle of light incident on the sample.

公开(公告)号：US20190170655A1

公开(公告)日：2019-06-06

申请号：US16197737

申请日：2018-11-21

申请人： Nanometrics Incorporated

发明人： Nigel P. Smith

IPC分类号： G01N21/88 ,  G01N21/21 ,  G01N21/95

摘要： An optical metrology device, such as an interferometer, detects sub-resolution defects on a sample, i.e., defects that are smaller than a pixel in the detector array of the interferometer. The optical metrology device obtains optical metrology data at each pixel in at least one detector array and determines parameter values of a signal model for a pixel of interest using the optical metrology data received by a plurality of pixels neighboring a pixel of interest. A residual for the pixel of interest is determined using the optical metrology data received by the pixel of interest and determined parameter values for the signal model for the pixel of interest. A defect, which may be smaller than the pixel of interest can then be detected based on the residual for the pixel of interest.

公开(公告)号：US10288408B2

公开(公告)日：2019-05-14

申请号：US15388794

申请日：2016-12-22

申请人： Nanometrics Incorporated

发明人： Nigel P. Smith ,  George Andrew Antonelli

IPC分类号： G01B9/02 ,  G01N21/45 ,  G02B21/00 ,  G01N21/956 ,  G01N21/21 ,  H01L21/66 ,  G02B21/14

摘要： A white light interferometric metrology device operates in the image plane and objective pupil plane. The interferometric metrology device extracts the electric field with complex parameters and that is a function of azimuth angle, angle of incidence and wavelength from interferometric data obtained from the pupil plane. Characteristics of the sample are determined using the electric field based on an electric field model of the azimuth angle, the angle of incidence and the wavelength that is specific for a zero diffraction order. A center of the pupil in the pupil plane may be determined based on a Fourier transform of the interferometric data at each new measurement and used to convert each pixel from the camera imaging the objective pupil plane into a unique set of angle of incidence and azimuth angle of light incident on the sample.