公开(公告)号：US20070188744A1

公开(公告)日：2007-08-16

申请号：US11738989

申请日：2007-04-23

申请人： Brian Leslie ,  Mehrdad Nikoonahad ,  Keith Wells

发明人： Brian Leslie ,  Mehrdad Nikoonahad ,  Keith Wells

IPC分类号： G01N21/88

CPC分类号： G01N21/95607 ,  G01N21/94 ,  G01N21/9501

摘要： In an optical scanning system for detecting particles and pattern defects on a sample surface, a light beam is focused to an illuminated spot on the surface and the spot is scanned across the surface along a scan line. A detector is positioned adjacent to the surface to collect scattered light from the spot where the detector includes a one- or two-dimensional array of sensors. Light scattered from the illuminated spot at each of a plurality of positions along the scan line is focused onto a corresponding sensor in the array. A plurality of detectors symmetrically placed with respect to the illuminating beam detect laterally and forward scattered light from the spot. The spot is scanned over arrays of scan line segments shorter than the dimensions of the surface. A bright field channel enables the adjustment of the height of the sample surface to correct for errors caused by height variations of the surface. Different defect maps provided by the output of the detectors can be compared to identify and classify the defects. The imaging function of the array of sensors combines the advantages of a scanning system and an imaging system while improving signal/background ratio of the system.

摘要翻译： 在用于检测样品表面上的颗粒和图案缺陷的光学扫描系统中，光束被聚焦到表面上的照明光斑上，并且沿着扫描线扫描光斑。 检测器邻近表面定位以收集来自检测器包括传感器的一维或二维阵列的点的散射光。 沿着扫描线的多个位置中的每一个处从照明点散射的光被聚焦到阵列中的对应的传感器上。 相对于照明光束对称放置的多个检测器检测来自光斑的横向和前向散射光。 在比表面尺寸短的扫描线段的阵列上扫描该点。 亮场通道可以调整样品表面的高度，以校正由表面的高度变化引起的误差。 可以比较由检测器输出提供的不同缺陷图，以识别和分类缺陷。 传感器阵列的成像功能结合了扫描系统和成像系统的优点，同时提高了系统的信号/背景比。

公开(公告)号：US06900892B2

公开(公告)日：2005-05-31

申请号：US09741663

申请日：2000-12-19

申请人： Andrei V. Shchegrov ,  Anatoly Fabrikant ,  Mehrdad Nikoonahad

发明人： Andrei V. Shchegrov ,  Anatoly Fabrikant ,  Mehrdad Nikoonahad

IPC分类号： G01J3/447 ,  G01J4/04 ,  G01N21/21 ,  G01J4/00

CPC分类号： H01L22/20 ,  G01J3/447 ,  G01J4/04 ,  G01N21/211

摘要： A gallery of seed profiles is constructed and the initial parameter values associated with the profiles are selected using manufacturing process knowledge of semiconductor devices. Manufacturing process knowledge may also be used to select the best seed profile and the best set of initial parameter values as the starting point of an optimization process whereby data associated with parameter values of the profile predicted by a model is compared to measured data in order to arrive at values of the parameters. Film layers over or under the periodic structure may also be taken into account. Different radiation parameters such as the reflectivities RS, RP and ellipsometric parameters may be used in measuring the diffracting structures and the associated films. Some of the radiation parameters may be more sensitive to a change in the parameter value of the profile or of the films then other radiation parameters. One or more radiation parameters that are more sensitive to such changes may be selected in the above-described optimization process to arrive at a more accurate measurement. The above-described techniques may be supplied to a track/stepper and etcher to control the lithographic and etching processes in order to compensate for any errors in the profile parameters.

摘要翻译： 构建种子轮廓的画廊，并且使用半导体器件的制造工艺知识来选择与轮廓相关联的初始参数值。 也可以使用制造过程知识来选择最佳种子轮廓和最佳初始参数值集合作为优化过程的起始点，由此将与模型预测的轮廓的参数值相关联的数据与测量数据进行比较，以便 达到参数的值。 也可以考虑在周期性结构之上或之下的膜层。 不同的辐射参数，例如反射率R S，R P和椭偏参数可用于测量衍射结构和相关膜。 一些辐射参数可能对轮廓或膜的参数值的变化对其他辐射参数更敏感。 可以在上述优化过程中选择对这种变化更敏感的一个或多个辐射参数，以获得更准确的测量。 可以将上述技术提供给轨道/步进器和蚀刻器以控制光刻和蚀刻工艺，以便补偿轮廓参数中的任何误差。

公开(公告)号：US06804003B1

公开(公告)日：2004-10-12

申请号：US09405716

申请日：1999-09-24

申请人： Haiming Wang ,  Patrick M. Maxton ,  Kenneth C. Johnson ,  Mehrdad Nikoonahad

发明人： Haiming Wang ,  Patrick M. Maxton ,  Kenneth C. Johnson ,  Mehrdad Nikoonahad

IPC分类号： G01J400

CPC分类号： G01J3/447 ,  G01B11/0641 ,  G01J4/02 ,  G01N21/21 ,  G01N21/211

摘要： Two phase modulators or polarizing elements are employed to modulate the polarization of an interrogating radiation beam before and after the beam has been modified by a sample to be measured. Radiation so modulated and modified by the sample is detected and up to 25 harmonics may be derived from the detected signal. The up to 25 harmonics may be used to derive ellipsometric and system parameters, such as parameters related to the angles of fixed polarizing elements, circular deattenuation, depolarization of the polarizing elements and retardances of phase modulators. A portion of the radiation may be diverted for detecting sample tilt or a change in sample height. A cylindrical objective may be used for focusing the beam onto the sample to illuminate a circular spot on the sample. The above-described self-calibrating ellipsometer may be combined with another optical measurement instrument such as a polarimeter, a spectroreflectometer or another ellipsometer to improve the accuracy of measurement and/or to provide calibration standards for the optical measurement instrument. The self-calibrating ellipsometer as well as the combined system may be used for measuring sample characteristics such as film thickness and depolarization of radiation caused by the sample.

摘要翻译： 采用两相调制器或偏振元件来调制光束已被待测样品修改之前和之后的询问辐射束的极化。 检测由样本调制和修改的辐射，并且可以从检测到的信号导出多达25个谐波。 可以使用多达25个谐波来导出椭偏和系统参数，例如与固定偏振元件的角度相关的参数，圆形去衰减，偏振元件的去极化和相位调制器的延迟。 可以转移一部分辐射以检测样品倾斜或样品高度的变化。 可以使用圆柱形物镜将光束聚焦到样品上以照亮样品上的圆形斑点。 上述自校准椭偏仪可以与另一种光学测量仪器如偏振计，分光光度计或其他椭偏仪组合，以提高测量精度和/或为光学测量仪器提供校准标准。 自校准椭偏仪以及组合系统可用于测量样品特性，如样品的膜厚度和辐射的去极化。

公开(公告)号：US06611330B2

公开(公告)日：2003-08-26

申请号：US09778245

申请日：2001-02-06

申请人： Shing Lee ,  Haiming Wang ,  Adam Norton ,  Mehrdad Nikoonahad

发明人： Shing Lee ,  Haiming Wang ,  Adam Norton ,  Mehrdad Nikoonahad

IPC分类号： G01N2121

CPC分类号： G01J4/02 ,  G01J3/447 ,  G01N21/21

摘要： A polarized sample beam of broadband radiation is focused onto the surface of a sample and the radiation modified by the sample is collected by means of a mirror system in different planes of incidence. The sample beam focused to the sample has a multitude of polarization states. The modified radiation is analyzed with respect to a polarization plane to provide a polarimetric spectrum. Thickness and refractive information may then be derived from the spectrum. Preferably the polarization of the sample beam is altered only by the focusing and the sample, and the analyzing is done with respect to a fixed polarization plane. In the preferred embodiment, the focusing of the sample beam and the collection of the modified radiation are repeated employing two different apertures to detect the presence or absence of a birefringence axis in the sample. In another preferred embodiment, the above-described technique may be combined with ellipsometry for determining the thicknesses and refractive indices of thin films.

公开(公告)号：US5576831A

公开(公告)日：1996-11-19

申请号：US263203

申请日：1994-06-20

申请人： Mehrdad Nikoonahad ,  James A. Tebelskis

发明人： Mehrdad Nikoonahad ,  James A. Tebelskis

IPC分类号： G01N21/95 ,  G01R31/28 ,  G01R31/308 ,  H01L21/66 ,  G01B11/00

CPC分类号： G01R31/308 ,  G01N21/9501 ,  G01R31/2831 ,  H01L22/12

摘要： A surface height detection and positioning device for use in a surface inspection system. An incident beam of light impinges obliquely upon the surface, and a position detector is disposed to receive light reflected from the surface. The position detector has a sensitivity characteristic graded along a direction transverse to the surface, so that the output of the position detector is used to determine a height of the surface. The device can be incorporated into a particle detection system that scans patterned wafers with obliquely incident light to search for particles with a particle detector positioned to receive scattered light. In one embodiment, the position detector can have a width that is graded along the direction transverse to the surface, so that a scan line on the surface that is focused upon the position detector crosses the width of that detector in a time that varies as a function of the height of the surface. This time can be measured as an electrical pulse from the position detector that can be used for various purposes, including adjusting the height of the surface during scanning. In another embodiment, the position detector can have a periodic variance in light sensitivity that is graded, so that varying a height of the surface varies a phase of the output from the position detector.

摘要翻译： 一种用于表面检测系统的表面高度检测和定位装置。 入射光束倾斜地撞击在表面上，并且设置位置检测器以接收从表面反射的光。 位置检测器具有沿横向于表面的方向分级的灵敏度特性，使得位置检测器的输出用于确定表面的高度。 该装置可以结合到使用倾斜入射光扫描图案化晶片的颗粒检测系统中，以用用于接收散射光的颗粒检测器搜索颗粒。 在一个实施例中，位置检测器可以具有沿着横向于表面的方向分级的宽度，使得聚焦在位置检测器上的表面上的扫描线在随时间变化的时间内穿过该检测器的宽度 表面高度的功能。 这个时间可以被测量为来自位置检测器的电脉冲，其可以用于各种目的，包括在扫描期间调整表面的高度。 在另一个实施例中，位置检测器可以具有渐变的光敏度的周期性变化，使得改变表面的高度改变来自位置检测器的输出的相位。

公开(公告)号：US5530550A

公开(公告)日：1996-06-25

申请号：US361131

申请日：1994-12-21

申请人： Mehrdad Nikoonahad ,  Philip R. Rigg ,  Keith B. Wells ,  David S. Calhoun

发明人： Mehrdad Nikoonahad ,  Philip R. Rigg ,  Keith B. Wells ,  David S. Calhoun

IPC分类号： G01B11/02 ,  G01B11/30 ,  G01N21/88 ,  G01N21/94 ,  G01N21/95 ,  G01N21/956 ,  H01L21/66 ,  G01B11/14

CPC分类号： G01N21/9501 ,  G01N21/94 ,  G01N21/956

摘要： The position detector has a sensitivity characteristic graded along a direction transverse to the surface, so that the output of the position detector is used to determine a height of the surface. A surface height detection and positioning device for use in a surface inspection system. An incident beam of light impinges obliquely upon the surface, and a position detector is disposed to receive specularly reflected light, producing a plurality of electrical signals, with a mechanical window, defining an aperture, placed in front of the detector. The aperture's width, along the scan direction, is of sufficient size so as to create a train of signals from each of the plurality of electrical signals, having a frequency equal to the scan frequency. These electrical signals carry information responsive to both the position of reflected beam impinging on the detector and the beam's intensity and are, in turn, related to a height of the surface. To abrogate information responsive to intensity variations at the position sensitive detector, an electronic circuit is employed which determines the sum and the difference of the plurality of signals relating to wafer height and beam intensity, producing a summed signal and a difference signal respectively. The difference signal is then divided by the summed signal, thereby producing a normalized signal which represents the height of the wafer surface without regards to these reflected beam intensity variations. These signals are synchronized to the scan frequency which facilitates removing unwanted signals resulting from thermal drifts and ambient light.

摘要翻译： 位置检测器具有沿横向于表面的方向分级的灵敏度特性，使得位置检测器的输出用于确定表面的高度。 一种用于表面检测系统的表面高度检测和定位装置。 入射光束倾斜地撞击在表面上，并且位置检测器被设置成接收镜面反射光，产生多个电信号，其中机械窗口限定放置在检测器前面的孔。 沿着扫描方向的孔径的宽度具有足够的尺寸，以便产生具有等于扫描频率的频率的来自多个电信号中的每一个的一串信号。 这些电信号响应于入射在检测器上的反射光束的位置和光束的强度而携带信息，并且又与表面的高度有关。 为了消除响应于位置敏感检测器的强度变化的信息，采用电子电路，其确定与晶片高度和光束强度相关的多个信号的总和和差异，分别产生求和信号和差分信号。 然后将差分信号除以相加的信号，从而产生表示晶片表面的高度的归一化信号，而不考虑这些反射的光束强度变化。 这些信号与扫描频率同步，有助于消除由热漂移和环境光引起的不必要的信号。

公开(公告)号：US5224482A

公开(公告)日：1993-07-06

申请号：US682515

申请日：1991-04-08

申请人： Mehrdad Nikoonahad ,  Erlvada A. Sivers

发明人： Mehrdad Nikoonahad ,  Erlvada A. Sivers

IPC分类号： A61B8/06 ,  G01F1/66 ,  G01F1/708 ,  G01P5/22 ,  G01S15/58 ,  G01S15/89

CPC分类号： G01F1/66 ,  A61B8/06 ,  G01F1/7082 ,  G01S15/582 ,  G01S15/8959

摘要： An ultrasound high velocity flow measurement apparatus uses cross-correlation between consecutive echoes of coded pulses which are matched filtered at the receiver to determine velocity profiles of flowing blood. Because coded pulses are used, the interval between two pulses can be made arbitrarily small, effectively removing the peak velocity limitation.

公开(公告)号：US07826071B2

公开(公告)日：2010-11-02

申请号：US11868740

申请日：2007-10-08

申请人： Andrei V. Shchegrov ,  Anatoly Fabrikant ,  Mehrdad Nikoonahad ,  Ady Levy ,  Daniel C. Wack ,  Noah Bareket ,  Walter Mieher ,  Ted Dziura

发明人： Andrei V. Shchegrov ,  Anatoly Fabrikant ,  Mehrdad Nikoonahad ,  Ady Levy ,  Daniel C. Wack ,  Noah Bareket ,  Walter Mieher ,  Ted Dziura

IPC分类号： G01B11/14

CPC分类号： G03F7/70616 ,  G01N21/211 ,  G01N21/47 ,  G01N21/4788 ,  G01N21/9501 ,  G01N21/956 ,  G01N21/95607 ,  G01N2021/213 ,  G03F7/70625 ,  G03F7/70641

摘要： A gallery of seed profiles is constructed and the initial parameter values associated with the profiles are selected using manufacturing process knowledge of semiconductor devices. Manufacturing process knowledge may also be used to select the best seed profile and the best set of initial parameter values as the starting point of an optimization process whereby data associated with parameter values of the profile predicted by a model is compared to measured data in order to arrive at values of the parameters. Film layers over or under the periodic structure may also be taken into account. Different radiation parameters such as the reflectivities Rs, Rp and ellipsometric parameters may be used in measuring the diffracting structures and the associated films. Some of the radiation parameters may be more sensitive to a change in the parameter value of the profile or of the films then other radiation parameters. One or more radiation parameters that are more sensitive to such changes may be selected in the above-described optimization process to arrive at a more accurate measurement. The above-described techniques may be supplied to a track/stepper and etcher to control the lithographic and etching processes in order to compensate for any errors in the profile parameters.

摘要翻译： 构建种子轮廓的画廊，并且使用半导体器件的制造工艺知识来选择与轮廓相关联的初始参数值。 也可以使用制造过程知识来选择最佳种子轮廓和最佳初始参数值集合作为优化过程的起始点，由此将与模型预测的轮廓的参数值相关联的数据与测量数据进行比较，以便 达到参数的值。 也可以考虑在周期性结构之上或之下的膜层。 可以使用诸如反射率Rs，Rp和椭偏参数的不同辐射参数来测量衍射结构和相关膜。 一些辐射参数可能对轮廓或膜的参数值的变化对其他辐射参数更敏感。 可以在上述优化过程中选择对这种变化更敏感的一个或多个辐射参数，以获得更准确的测量。 可以将上述技术提供给轨道/步进器和蚀刻器以控制光刻和蚀刻工艺，以便补偿轮廓参数中的任何误差。

公开(公告)号：US20060203235A1

公开(公告)日：2006-09-14

申请号：US11421933

申请日：2006-06-02

申请人： Brian Leslie ,  Mehrdad Nikoonahad ,  Keith Wells

发明人： Brian Leslie ,  Mehrdad Nikoonahad ,  Keith Wells

IPC分类号： G01N21/88

CPC分类号： G01N21/95607 ,  G01N21/94 ,  G01N21/9501

摘要： In an optical scanning system for detecting particles and pattern defects on a sample surface, a light beam is focused to an illuminated spot on the surface and the spot is scanned across the surface along a scan line. A detector is positioned adjacent to the surface to collect scattered light from the spot where the detector includes a one- or two-dimensional array of sensors. Light scattered from the illuminated spot at each of a plurality of positions along the scan line is focused onto a corresponding sensor in the array. A plurality of detectors symmetrically placed with respect to the illuminating beam detect laterally and forward scattered light from the spot. The spot is scanned over arrays of scan line segments shorter than the dimensions of the surface. A bright field channel enables the adjustment of the height of the sample surface to correct for errors caused by height variations of the surface. Different defect maps provided by the output of the detectors can be compared to identify and classify the defects. The imaging function of the array of sensors combines the advantages of a scanning system and an imaging system while improving signal/background ratio of the system.

摘要翻译： 在用于检测样品表面上的颗粒和图案缺陷的光学扫描系统中，光束被聚焦到表面上的照明光斑上，并且沿着扫描线扫描光斑。 检测器邻近表面定位以收集来自检测器包括传感器的一维或二维阵列的点的散射光。 沿着扫描线的多个位置中的每一个处从照明点散射的光被聚焦到阵列中的对应的传感器上。 相对于照明光束对称放置的多个检测器检测来自光斑的横向和前向散射光。 在比表面尺寸短的扫描线段的阵列上扫描该点。 亮场通道可以调整样品表面的高度，以校正由表面的高度变化引起的误差。 可以比较由检测器输出提供的不同缺陷图，以识别和分类缺陷。 传感器阵列的成像功能结合了扫描系统和成像系统的优点，同时提高了系统的信号/背景比。

公开(公告)号：US07075637B2

公开(公告)日：2006-07-11

申请号：US10412458

申请日：2003-04-10

申请人： Brian C. Leslie ,  Mehrdad Nikoonahad ,  Keith B. Wells

发明人： Brian C. Leslie ,  Mehrdad Nikoonahad ,  Keith B. Wells

IPC分类号： G01N21/00

CPC分类号： G01N21/95607 ,  G01N21/94 ,  G01N21/9501

摘要： In an optical scanning system for detecting particles and pattern defects on a sample surface, a light beam is focused to an illuminated spot on the surface and the spot is scanned across the surface along a scan line. A detector is positioned adjacent to the surface to collect scattered light from the spot where the detector includes a one- or two-dimensional array of sensors. Light scattered from the illuminated spot at each of a plurality of positions along the scan line is focused onto a corresponding sensor in the array. A plurality of detectors symmetrically placed with respect to the illuminating beam detect laterally and forward scattered light from the spot. The spot is scanned over arrays of scan line segments shorter than the dimensions of the surface. A bright field channel enables the adjustment of the height of the sample surface to correct for errors caused by height variations of the surface. Different defect maps provided by the output of the detectors can be compared to identify and classify the defects. The imaging function of the array of sensors combines the advantages of a scanning system and an imaging system while improving signal/background ratio of the system.