公开(公告)号：US06453006B1

公开(公告)日：2002-09-17

申请号：US09527389

申请日：2000-03-16

Applicant: Louis N. Koppel ,  Craig E. Uhrich ,  Jon Opsal

Inventor： Louis N. Koppel ,  Craig E. Uhrich ,  Jon Opsal

IPC: G01N23201

CPC classification number: G01N23/20

Abstract: The present invention relates to the calibration and alignment of an X-ray reflectometry (“XRR”) system for measuring thin films. An aspect of the present invention describes a method for accurately determining C0 for each sample placement and for finding the incident X-ray intensity corresponding to each pixel of a detector array and thus permitting an amplitude calibration of the reflectometer system. Another aspect of the present invention relates to a method for aligning an angle-resolved X-ray reflectometer that uses a focusing optic, which may preferably be a Johansson crystal. Another aspect of the present invention is to validate the focusing optic. Another aspect of the present invention relates to the alignment of the focusing optic with the X-ray source. Another aspect of the present invention concerns the correction of measurements errors caused by the tilt or slope of the sample. Yet another aspect of the present invention concerns the calibration of the vertical position of the sample.

Abstract translation: 本发明涉及用于测量薄膜的X射线反射测量（“XRR”）系统的校准和对准。 本发明的一个方面描述了一种用于准确地确定每个样本放置的C0并且用于找到对应于检测器阵列的每个像素的入射X射线强度并因此允许反射计系统的幅度校准的方法。 本发明的另一方面涉及一种用于对准使用聚焦光学元件的角度分辨X射线反射计的方法，其可以优选地是约翰逊晶体。 本发明的另一方面是验证聚焦光学元件。 本发明的另一方面涉及聚焦光学元件与X射线源的对准。 本发明的另一方面涉及由样品的倾斜或斜率引起的测量误差的校正。 本发明的另一方面涉及到样品的垂直位置的校准。

公开(公告)号：US06429943B1

公开(公告)日：2002-08-06

申请号：US09818703

申请日：2001-03-27

Applicant: Jon Opsal ,  Allan Rosencwaig

Inventor： Jon Opsal ,  Allan Rosencwaig

IPC: C01B1114

CPC classification number: G01B11/024 ,  G01B11/02 ,  G01B11/14 ,  G03F7/70625

Abstract: A method and apparatus are disclosed for evaluating relatively small periodic structures formed on semiconductor samples. In this approach, a light source generates a probe beam which is directed to the sample. In one preferred embodiment, an incoherent light source is used. A lens is used to focus the probe beam on the sample in a manner so that rays within the probe beam create a spread of angles of incidence. The size of the probe beam spot on the sample is larger than the spacing between the features of the periodic structure so some of the light is scattered from the structure. A detector is provided for monitoring the reflected and scattered light. The detector includes multiple detector elements arranged so that multiple output signals are generated simultaneously and correspond to multiple angles of incidence. The output signals are supplied to a processor which analyzes the signals according to a scattering model which permits evaluation of the geometry of the periodic structure. In one embodiment, the sample is scanned with respect to the probe beam and output signals are generated as a function of position of the probe beam spot.

Abstract translation: 公开了一种用于评估在半导体样品上形成的相对小的周期性结构的方法和装置。 在这种方法中，光源产生指向样品的探针束。 在一个优选实施例中，使用非相干光源。 使用透镜将探针束聚焦在样品上，使得探针束内的射线产生入射角的扩展。 样品上的探针光斑的尺寸大于周期结构特征之间的间距，所以一些光从结构散射。 提供了一种用于监测反射和散射光的检测器。 检测器包括多个检测器元件，其布置成使得多个输出信号同时产生并对应于多个入射角。 输出信号被提供给处理器，该处理器根据允许评估周期性结构的几何形状的散射模型分析信号。 在一个实施例中，相对于探测光束扫描样品，并且根据探针束斑的位置产生输出信号。

公开(公告)号：US5973787A

公开(公告)日：1999-10-26

申请号：US76673

申请日：1998-05-12

Applicant: David E. Aspnes ,  Jon Opsal

Inventor： David E. Aspnes ,  Jon Opsal

IPC: G01N21/21 ,  G01B11/06 ,  G01J3/02 ,  G01J3/447 ,  G01J4/00 ,  G01J4/04 ,  G02F1/01

CPC classification number: G01J3/02 ,  G01J3/0229 ,  G01J3/0232 ,  G01N21/211 ,  G01N2021/213

Abstract: An ellipsometer, and a method of ellipsometry, for analyzing a sample using a broad range of wavelengths, includes a light source for generating a beam of polychromatic light having a range of wavelengths of light for interacting with the sample. A polarizer polarizes the light beam before the light beam interacts with the sample. A rotating compensator induces phase retardations of a polarization state of the light beam wherein the range of wavelengths and the compensator are selected such that at least a first phase retardation value is induced that is within a primary range of effective retardations of substantially 135.degree. to 225.degree., and at least a second phase retardation value is induced that is outside of the primary range. An analyzer interacts with the light beam after the light beam interacts with the sample. A detector measures the intensity of light after interacting with the analyzer as a function of compensator angle and of wavelength, preferably at all wavelengths simultaneously. A processor determines the polarization state of the beam as it impinges the analyzer from the light intensities measured by the detector.

公开(公告)号：US5798837A

公开(公告)日：1998-08-25

申请号：US890697

申请日：1997-07-11

Applicant: David E. Aspnes ,  Jon Opsal ,  Jeffrey T. Fanton

Inventor： David E. Aspnes ,  Jon Opsal ,  Jeffrey T. Fanton

IPC: G01B11/06 ,  G01J4/00 ,  G01N21/21

CPC classification number: G01B11/0641 ,  G01J4/00 ,  G01N21/211

Abstract: An optical measurement system for evaluating a reference sample that has at least a partially known composition. The optical measurement system includes a reference ellipsometer and at least one non-contact optical measurement device. The reference ellipsometer includes a light generator, an analyzer and a detector. The light generator generates a beam of quasi-monochromatic light having a known wavelength and a known polarization for interacting with the reference sample. The beam is directed at a non-normal angle of incidence relative to the reference sample to interact with the reference sample. The analyzer creates interference between the S and P polarized components in the light beam after the light beam has interacted with reference sample. The detector measures the intensity of the light beam after it has passed through the analyzer. A processor determines the polarization state of the light beam entering the analyzer from the intensity measured by the detector, and determines an optical property of the reference sample based upon the determined polarization state, the known wavelength of light from the light generator and the composition of the reference sample. The processor also operates the optical measurement device to measure an optical parameter of the reference sample. The processor calibrates the optical measurement device by comparing the measured optical parameter from the optical measurement device to the determined optical property from the reference ellipsometer.

公开(公告)号：US5596411A

公开(公告)日：1997-01-21

申请号：US614522

申请日：1996-03-18

Applicant: Jeffrey T. Fanton ,  Jon Opsal

Inventor： Jeffrey T. Fanton ,  Jon Opsal

IPC: G01N21/21 ,  G01N21/27 ,  G01J4/00

CPC classification number: G01N21/211

Abstract: An optical inspection apparatus is disclosed for generating an ellipsometric output signal at a plurality of wavelengths, each signal being representative of an integration of measurements at a plurality of angles of incidence. A polarized, broad band light beam is focused through a lens onto a sample in a manner to create a spread of angles of incidence. The reflected beam is passed through a quarter-wave plate and a polarizer which creates interference effects between the two polarizations states in the beam. The beam is then passed through a filter which transmits two opposed radial quadrants of the beam and blocks light striking the remaining two quadrants. The beam is then focused and angularly dispersed as function of wavelength. Each element of a one dimensional photodetector array generates an output signal associated with a specific wavelength and represents an integration of the phase-sensitive ellipsometric parameter (.delta.) at a plurality of angles of incidence. A second, independent measurement is taken in order to isolate the signal of interest. In one embodiment, the azimuthal angle of the filter is rotated by ninety degrees. The output signals from the second measurement are subtracted from the corresponding output signals from the first measurement to obtain the phase-sensitive ellipsometric information at a plurality of wavelengths. The ellipsometric information is used to analyze the sample.

Abstract translation: 公开了一种用于在多个波长处产生椭偏输出信号的光学检查装置，每个信号代表多个入射角的测量的积分。 极化的宽带光束以透镜角度聚焦到样品上，以产生入射角的扩展。 反射光束通过四分之一波片和偏振器，在光束中的两个极化状态之间产生干涉效应。 然后将光束通过过滤器，该过滤器透射两个相对的辐射象限的光束并阻挡发射到剩余的两个象限的光。 然后将光束聚焦并作为波长的函数成角度地分散。 一维光电检测器阵列的每个元件产生与特定波长相关联的输出信号，并且表示多个入射角的相敏椭偏参数（delta）的积分。 进行第二次独立测量以便隔离感兴趣的信号。 在一个实施例中，过滤器的方位角旋转九十度。 从第一测量的相应输出信号中减去来自第二测量的输出信号，以获得多个波长的相敏椭偏信息。 椭偏信息用于分析样品。

公开(公告)号：US5159412A

公开(公告)日：1992-10-27

申请号：US670040

申请日：1991-03-15

Applicant: David L. Willenborg ,  Allan Rosencwaig ,  Jon Opsal

Inventor： David L. Willenborg ,  Allan Rosencwaig ,  Jon Opsal

IPC: G01B11/06 ,  G01M11/00 ,  G01N21/21 ,  G01N21/55 ,  G01N21/84

CPC classification number: G01N21/55 ,  G01B11/0616 ,  G01N21/211 ,  G01N21/8422 ,  G01N2201/064

Abstract: An approach for increasing the sensitivity of a high resolution measurement device 50 is disclosed. The device includes a laser 52 for generating a probe beam 54 which is tightly focused onto the surface of the sample 58. A detector 66 is provided for monitoring a parameter of the reflected probe beam. In accordance with the subject invention, a spatial filter is provided for reducing the amount of light energy reaching the detector that has been reflected from areas on the surface of the sample beyond the focused spot. The spatial filter includes a relay lens 68 and a blocking member 70 located in the focal plane of the lens. The blocking member 70 includes an aperture 72 dimensioned to block light reflected from the surface of the sample beyond a predetermined distance from the center of the focused spot. In this manner, greater sensitivity to sample characteristics within the highly focused spot is achieved.

公开(公告)号：US4999014A

公开(公告)日：1991-03-12

申请号：US347812

申请日：1989-05-04

Applicant: Nathan Gold ,  David L. Willenborg ,  Jon Opsal ,  Allan Rosencwaig

Inventor： Nathan Gold ,  David L. Willenborg ,  Jon Opsal ,  Allan Rosencwaig

IPC: G01B11/06 ,  G01N21/21

CPC classification number: G01N21/211

Abstract: An apparatus (20) for measuring the thickness of a thin film layer (32) on substrate (28) includes a probe beam of radiation (24) focused substantially normal to the surface of the sample using a high numerical aperture lens (30). The high numerical aperture lens (30) provides a large spread of angles of incidence of the rays within the incident focused beam. A detector (50) measures the intensity across the reflected probe beam as a function of the angle of incidence with respect to the surface of the substrate (28) of various rays within the focused incident probe beam. A processor (52) functions to derive the thickness of the thin film layer based on these angular dependent intensity measurements. This result is achieved by using the angular dependent intensity measurements to solve the layer thickness using variations of the Fresnel equations. The invention is particularly suitable for measuring thin films, such as oxide layers, on silicon semiconductor samples.

公开(公告)号：US4679946A

公开(公告)日：1987-07-14

申请号：US612077

申请日：1984-05-21

Applicant: Allan Rosencwaig ,  Jon Opsal

Inventor： Allan Rosencwaig ,  Jon Opsal

IPC: G01N25/00 ,  G01B11/06 ,  G01N21/17 ,  G01N21/21 ,  G01N21/55 ,  G01N25/18 ,  G01N25/72 ,  G01N29/00 ,  G01N21/41

CPC classification number: G01N21/1702 ,  G01B11/0658 ,  G01N21/55 ,  G01N25/72 ,  G01N21/21 ,  G01N2201/1087

Abstract: The subject invention discloses a method and apparatus for evaluating both the thickness and compositional variables in a layered or thin film sample. Two independent detection systems are provided for measuring thermal waves generated in a sample by a periodic, localized heating. One detection system is of the type that generates output signals that are primarily a function of the surface temperature of the sample. The other detection system generates signals that are primarily a function of the integral of the temperature beneath the sample surface. The two independent thermal wave measurements permit analysis of both thickness and compositional variables. An apparatus is disclosed wherein both detection systems can be implemented efficiently within one apparatus.

Abstract translation: 本发明公开了一种用于评估层状或薄膜样品中的厚度和组成变量的方法和装置。 提供了两个独立的检测系统，用于通过周期性的局部加热来测量样品中产生的热波。 一种检测系统是产生主要是样品表面温度的函数的输出信号的类型。 另一个检测系统产生主要是样品表面下方温度积分函数的信号。 两个独立的热波测量允许分析厚度和组成变量。 公开了一种在一个装置内可以有效地实现两个检测系统的装置。

公开(公告)号：US4634290A

公开(公告)日：1987-01-06

申请号：US797949

申请日：1985-11-14

Applicant: Allan Rosencwaig ,  Jon Opsal

Inventor： Allan Rosencwaig ,  Jon Opsal

IPC: G01N21/55 ,  G01N25/00 ,  G01N25/72 ,  G01N21/41

CPC classification number: G01N25/00 ,  G01N21/55 ,  G01N25/72

Abstract: A method and apparatus is disclosed for detecting thermal waves. This system is based on the measurement of the change in reflectivity at the sample surface which is a function of the changing surface temperature. The apparatus includes a radiation probe beam that is directed on a portion of the area which is being periodically heated. A photodetector is aligned to sense the intensity changes in the reflected radiation probe beam which results from the periodic heating. These signals are processed to detect the presence of thermal waves.

Abstract translation: 公开了一种用于检测热波的方法和装置。 该系统基于样品表面的反射率变化的测量，该变化是表面温度变化的函数。 该装置包括一个辐射探针光束，该辐射探针光束被定向在正被周期性地加热的区域的一部分上。 对准光电检测器以感测由周期性加热产生的反射辐射探针光束的强度变化。 处理这些信号以检测热波的存在。

公开(公告)号：US07705977B2

公开(公告)日：2010-04-27

申请号：US11998118

申请日：2007-11-28

Applicant: Alex Salnik ,  Jon Opsal ,  Lena Nicolaides

Inventor： Alex Salnik ,  Jon Opsal ,  Lena Nicolaides

IPC: G01N21/00

CPC classification number: G01N21/1717 ,  G01N2021/1719 ,  G01N2021/178

Abstract: Methods of obtaining dopant and damage depth profile information are disclosed using modulated optical reflectivity (MOR) measurements. In one aspect, the depth profile is constructed using information obtained from various measurements such as the junction depth, junction abruptness and dopant concentration. In another aspect, a full theoretical model is developed. Actual measurements are fed to the model. Using an iterative approach, the actual measurements are compared to theoretical measurements calculated from the model to determine the actual depth profile.

Abstract translation: 使用调制光学反射率（MOR）测量公开了获得掺杂剂和损伤深度分布信息的方法。 在一个方面，使用从诸如结深度，结突起和掺杂剂浓度的各种测量获得的信息来构建深度分布。 另一方面，开发了一个完整的理论模型。 实际测量被馈送到模型。 使用迭代方法，将实际测量与从模型计算的理论测量值进行比较，以确定实际深度分布。