公开(公告)号：US06891628B2

公开(公告)日：2005-05-10

申请号：US10607410

申请日：2003-06-25

Applicant: Guoguang Li ,  Phillip Walsh ,  Abdul R. Forouhi

Inventor： Guoguang Li ,  Phillip Walsh ,  Abdul R. Forouhi

IPC: G01B11/06 ,  G01N21/47 ,  G01N21/59 ,  G01N21/956 ,  G01B11/00

CPC classification number: G01B11/0625 ,  G01N21/4788 ,  G01N21/59 ,  G01N21/956 ,  G01N2021/4735

Abstract: An apparatus and method for determining a physical parameter of features on a substrate by illuminating the substrate with an incident light covering an incident wavelength range Δλ, e.g., from 190 nm to 1000 nm, where the substrate is at least semi-transparent. A response light received from the substrate and the feature is measured to obtain a response spectrum of the response light. Further, a complex-valued response due to the feature and the substrate is computed and both the response spectrum and the complex-valued response are used in determining the physical parameter. The response light is reflected light, transmitted light or a combination of the two. The complex-valued response typically includes a complex reflectance amplitude, a complex transmittance amplitude or both. The apparatus and method take into account the effects of vertical and lateral coherence length and are well suited for examining adjacent features.

Abstract translation: 一种用于通过用覆盖入射波长范围（例如190nm至1000nm）的入射光照射衬底来确定衬底上特征的物理参数的装置和方法，其中衬底至少是半透明的。 测量从衬底接收的响应光和特征以获得响应光的响应光谱。 此外，计算由特征和衬底引起的复值响应，并且在确定物理参数中使用响应谱和复值响应。 响应光是反射光，透射光或两者的组合。 复值响应通常包括复反射幅度，复透射幅度或二者。 该装置和方法考虑到纵向和横向相干长度的影响，并且非常适合于检查相邻特征。

公开(公告)号：US06580515B1

公开(公告)日：2003-06-17

申请号：US09870350

申请日：2001-05-29

Applicant: Guoguang Li ,  Rajeshwar C. Chhibber

Inventor： Guoguang Li ,  Rajeshwar C. Chhibber

IPC: G01B1102

CPC classification number: G01B11/303 ,  G01B11/0675

Abstract: A differential interferometer is used to measure the step height between a reference region and at least one point in a measurement region using the relative phase difference as well as the measured reflectance from at least the point in the measurement region. The measured reflectance can be derived from the information provided by the differential interferometer. The measured reflectance from the reference region can also be used to provide a step height measured, where, e.g., the reference region has a changing thickness. Where the measurement region includes a composite material, e.g., copper and silicon dioxide, the step height between the reference region and the measurement region may be determined by including the area fraction or the height difference of the materials in the composite material in the final determination of the step height.

Abstract translation: 差分干涉仪用于使用相对相位差以及至少在测量区域中的点测量的反射率来测量参考区域和测量区域中的至少一个点之间的台阶高度。 测量的反射率可以从差分干涉仪提供的信息导出。 来自参考区域的测量的反射率也可以用于提供测量的台阶高度，其中例如参考区域具有变化的厚度。 当测量区域包括复合材料（例如铜和二氧化硅）时，参考区域和测量区域之间的台阶高度可以通过在最终确定中包括复合材料中的材料的面积分数或高度差来确定 的步高。

公开(公告)号：US06392756B1

公开(公告)日：2002-05-21

申请号：US09336404

申请日：1999-06-18

Applicant: Guoguang Li ,  Hongwei Zhu ,  Dale A. Harrison ,  Abdul Rahim Forouhi ,  Weilu Xu

Inventor： Guoguang Li ,  Hongwei Zhu ,  Dale A. Harrison ,  Abdul Rahim Forouhi ,  Weilu Xu

IPC: G01B1106

CPC classification number: G01B11/0641

Abstract: A method and an apparatus for optically determining a physical parameter such as thickness t, index of refraction n, extinction coefficient k or a related physical parameter such as energy bandgap Eg of a thin film. A test beam having a wavelength range &Dgr;&lgr; is used to illuminate the thin film after it is deposited on a complex substrate which has at least two layers and exhibits a non-monotonic and an appreciably variable substrate optical response over wavelength range &Dgr;&lgr;. Alternatively, the thin film can be deposited between the at least two layers of the complex substrate. A measurement of a total optical response, consisting of the substrate optical response and an optical response difference due to the thin film is performed over wavelength range &Dgr;&lgr;. The at least two layers making up the complex substrate are chosen such that the effect of multiple internal reflections in the complex substrate and the film is maximized. The physical parameters are determined from the total optical response which can be in the form of a reflected and/or a transmitted beam.

Abstract translation: 用于光学地确定诸如厚度t，折射率n，消光系数k或相关物理参数（诸如薄膜的能带隙Eg）的物理参数的方法和装置。 具有波长范围DELTAlambd的测试光束在其沉积在具有至少两层的复合衬底上并且在波长范围DELTAlambd上表现出非单调和可观的可变衬底光学响应之后，用于照射薄膜。 或者，薄膜可以沉积在复合基板的至少两层之间。 在波长范围DELTAlambd上执行由基板光学响应和由薄膜引起的光学响应差异的总光学响应的​​测量。 选择构成复合衬底的至少两层，使得复合衬底和膜中的多次内部反射的影响最大化。 物理参数由可以是反射和/或透射束形式的总光学响应确定。

公开(公告)号：US09176048B2

公开(公告)日：2015-11-03

申请号：US13696054

申请日：2011-06-01

Applicant: Guoguang Li ,  Tao Liu ,  Edgar Genio ,  Tiezhong Ma ,  Xiaolang Yan

Inventor： Guoguang Li ,  Tao Liu ,  Edgar Genio ,  Tiezhong Ma ,  Xiaolang Yan

IPC: G01J4/00 ,  G01N21/21 ,  G01J3/02

CPC classification number: G01N21/211 ,  G01J3/02 ,  G01J3/0208 ,  G01J3/021 ,  G01J3/0224 ,  G01N21/21

Abstract: A kind of normal incidence broadband spectroscopic polarimeter which is easy to adjust the focus, has no chromatic aberration, maintains the polarization and has simple structure. The normal incidence broadband spectroscopic polarimeter can make the probe beam normal incidence and focus on the sample surface by using at least one flat reflector element to change propagation direction of the focused beam. Moreover, the normal incidence broadband spectroscopic polarimeter contains at least one polarizer as to measure the anisotropy or non-uniform samples, such as three-dimensional profile and material optical constants of thin films consisting of the periodic structure. An optical measurement system including the normal incidence broadband spectroscopic polarimeter is also provided.

Abstract translation: 一种正常入射的宽带光谱旋光计，易于调焦，无色差，维持极化，结构简单。 正常入射的宽带光谱旋光仪可以通过使用至少一个平面反射器元件来改变聚焦光束的传播方向，使探针光束正常入射并聚焦在样品表面上。 此外，正常入射的宽带光谱旋光计包含至少一个偏振器，用于测量各向异性或非均匀样品，例如由周期性结构构成的薄膜的三维轮廓和材料光学常数。 还提供了包括正常入射宽带光谱旋光计的光学测量系统。

公开(公告)号：US08767209B2

公开(公告)日：2014-07-01

申请号：US13701698

申请日：2011-05-30

Applicant: Guoguang Li ,  Tao Liu ,  Edgar Genio ,  Tiezhong Ma ,  Yan Xiaolang

Inventor： Guoguang Li ,  Tao Liu ,  Edgar Genio ,  Tiezhong Ma ,  Yan Xiaolang

IPC: G01J4/00 ,  G01N21/21

CPC classification number: G01N21/211 ,  G01J3/02 ,  G01J3/0208 ,  G01J3/021 ,  G01J3/0224 ,  G01N21/21

Abstract: An oblique incidence broadband spectroscopic polarimeter which is easy to adjust the focus, achromatic, maintains the polarization and has simple structure is provided. It comprise at least one polarizer (P, A), at least one curved reflector element (OAP1, OAP2, OAP3, OAP4) and at least two flat reflector elements (M1, M2). By utilizing the flat reflector element, the oblique incidence broadband spectroscopic polarimeter can change the propagate direction of beam, and compensate the polarization changes caused by the reflective focusing unit, make the polarization of beam passed the polarizer unchanged when obliquely incident and focus on the sample surface. The oblique incidence broadband spectroscopic polarimeter can accurately measure the optical constants of sample material, film thickness, and/or the critical dimension (CD) properties or three-dimensional profile for analyze the periodic structure of the sample. An optical measurement system including the oblique incidence broadband spectroscopic polarimeter is also provided.

Abstract translation: 提供了一种易于调整焦点，消色差，保持极化并具有简单结构的倾斜入射宽带光谱偏振计。 它包括至少一个偏振器（P，A），至少一个弯曲反射器元件（OAP1，OAP2，OAP3，OAP4）和至少两个平面反射器元件（M1，M2）。 通过利用平面反射元件，倾斜入射宽带光谱旋光计可以改变光束的传播方向，并补偿由反射聚焦单元引起的偏振变化，使得当倾斜入射时光束的偏振通过偏振器不变，并聚焦在样品上 表面。 倾斜入射宽带光谱旋光计可以精确测量样品材料的光学常数，膜厚度和/或临界尺寸（CD）性质或三维轮廓，以分析样品的周期性结构。 还提供了包括斜入射宽带光谱偏振计的光学测量系统。

公开(公告)号：US07289214B1

公开(公告)日：2007-10-30

申请号：US10997210

申请日：2004-11-23

Applicant: Guoguang Li ,  Shuqiang Chen ,  Abdul Rahim Forouhi

Inventor： Guoguang Li ,  Shuqiang Chen ,  Abdul Rahim Forouhi

IPC: G01G11/00

CPC classification number: G03F9/7076 ,  G03F7/70633

Abstract: A system and method for optical offset measurement is provided. An offset between two grating layers in a compound grating is measured by illuminating the gratings with light having a plane of incidence that is neither parallel with nor perpendicular to the grating lines. This non-symmetrical optical illumination allows determination of the sign and magnitude of the offset. Two measurements are performed at azimuthal angles separated by 180°, and a difference of these measurements is calculated. Measurement of this difference allows determination of the offset (e.g., with a calibration curve). Alternatively, two compound gratings having a predetermined non-zero offset difference can be employed. This arrangement permits determination of the offsets without the need for a calibration curve (or for additional compound gratings), based on a linear approximation.

Abstract translation: 提供了一种用于光学偏移测量的系统和方法。 复合光栅中的两个光栅层之间的偏移通过用不具有平行于或不垂直于光栅线的入射平面的光照射光栅来测量。 这种非对称光学照明允许确定偏移的符号和幅度。 在以180°分开的方位角进行两次测量，并计算这些测量值的差。 该差异的测量允许确定偏移（例如，利用校准曲线）。 或者，可以采用具有预定非零偏移差的两个复合光栅。 这种布置允许基于线性近似来确定偏移而不需要校准曲线（或用于附加复合光栅）。

公开(公告)号：US07253909B1

公开(公告)日：2007-08-07

申请号：US11028894

申请日：2005-01-03

Applicant: Guoguang Li ,  Phillip Walsh ,  Shuqiang Chen ,  Abdul Rahim Forouhi

Inventor： Guoguang Li ,  Phillip Walsh ,  Shuqiang Chen ,  Abdul Rahim Forouhi

IPC: G01B11/00

CPC classification number: G01B11/0625 ,  G01N21/4788 ,  G01N21/59 ,  G01N21/956 ,  G01N2021/4735

Abstract: An apparatus and method for determining a physical parameter of features on a substrate by illuminating the substrate with an incident light covering an incident wavelength range Δλ, e.g., from 190 nm to 1000 nm, where the substrate is at least semi-transparent. A response light received from the substrate and the feature is measured to obtain a response spectrum of the response light. Further, a complex-valued response due to the feature and the substrate is computed and both the response spectrum and the complex-valued response are used in determining the physical parameter. A direct approximate phase measurement is provided when the response light is transmitted light.

Abstract translation: 一种用于通过用覆盖入射波长范围（例如190nm至1000nm）的入射光照射衬底来确定衬底上特征的物理参数的装置和方法，其中衬底至少是半透明的。 测量从衬底接收的响应光和特征以获得响应光的响应光谱。 此外，计算由特征和衬底引起的复值响应，并且在确定物理参数中使用响应谱和复值响应。 当响应光透射光时，提供直接近似相位测量。

公开(公告)号：US06379014B1

公开(公告)日：2002-04-30

申请号：US09560504

申请日：2000-04-27

Applicant: Guoguang Li ,  Dale A. Harrison ,  Abdul Rahim Forouhi

Inventor： Guoguang Li ,  Dale A. Harrison ,  Abdul Rahim Forouhi

IPC: G02B111

CPC classification number: G03F7/70958 ,  G02B1/115 ,  Y10T428/12653

Abstract: A graded anti-reflective coating (ARC) with one or more layers has a bottom layer that is highly absorbing at the lithographic wavelength, and one or more layers between the substrate and the resist layer having inhomogeneous optical constants. The refractive indices are matched across layer interfaces, and the optical constants vary smoothly through the layer thicknesses. In each layer the extinction coefficient and the refractive index have independently selectable values and gradients. This ARC structure provides almost total absorption in the bottom layer and near-zero reflection at the resist interface and all other intermediate interfaces. Layers are preferably of inorganic materials, typically SiOxNy. Because of its highly absorbing bottom layer, an ARC according to an embodiment of the present invention works effectively over diverse substrate materials for a variety of lithographic wavelengths. It provides great latitude of manufacturing tolerances for thicknesses and optical constants.

Abstract translation: 具有一层或多层的梯度抗反射涂层（ARC）具有在光刻波长处高度吸收的底层，并且基板和抗蚀剂层之间的一层或多层具有不均匀的光学常数。 折射率跨层界面匹配，光学常数通过层厚度平滑变化。 在每个层中，消光系数和折射率具有独立的可选值和梯度。 该ARC结构在抗蚀剂界面和所有其它中间界面处在底层几乎全部吸收和近零反射。 层优选为无机材料，通常为SiO x N y。 由于其高度吸收的底层，根据本发明的实施例的ARC可以有效地用于各种光刻波长的不同的衬底材料。 它为厚度和光学常数的制造公差提供了很大的自由度。

公开(公告)号：US06327035B1

公开(公告)日：2001-12-04

申请号：US09451465

申请日：1999-11-30

Applicant: Guoguang Li ,  Dale A. Harrison ,  Abdul Rahim Forouhi

Inventor： Guoguang Li ,  Dale A. Harrison ,  Abdul Rahim Forouhi

IPC: G01N2100

CPC classification number: G03F7/70616

Abstract: A method and apparatus for optically determining a physical parameter a pattern made up of features and disposed on an underlayer. The physical parameter can be, e.g., feature width, relative feature size, feature thickness, index of refraction n or extinction coefficient k and is determined from a response light generated upon illumination of the pattern and underlayer. The response light, e.g. light transmitted by or reflected from the pattern and from the underlayer is analyzed and broken down into response light fractions including an underlayer light fraction and a feature light fraction as well as any other background light fractions making up the response light. The physical parameter of the pattern is determined from the response light fractions and reference physical parameters) of the underlayer, which are either known a priori or determined.

Abstract translation: 一种用于光学地确定由特征构成并布置在底层上的图案的物理参数的方法和装置。 物理参数可以是例如特征宽度，相对特征尺寸，特征厚度，折射率n或消光系数k，并且根据照射图案和底层时产生的响应光来确定。 响应光，例如 从图案和底层透射或反射的光被分析并分解成包括底层光分数和特征光分数的响应轻分数以及构成响应光的任何其它背景轻馏分。 根据已知先验或确定的底层的反应轻分数和参考物理参数确定图案的物理参数）。

公开(公告)号：US09170156B2

公开(公告)日：2015-10-27

申请号：US14366637

申请日：2012-09-06

Applicant: Guoguang Li ,  Tao Liu ,  Jiangyan Zhao ,  Qingyang Guo ,  Edgar Genio ,  Tiezhong Ma ,  Yang Xia

Inventor： Guoguang Li ,  Tao Liu ,  Jiangyan Zhao ,  Qingyang Guo ,  Edgar Genio ,  Tiezhong Ma ,  Yang Xia

IPC: G01J4/00 ,  G01J3/447 ,  G02B27/14 ,  G02B27/40 ,  G01J3/42 ,  G01J3/02 ,  G01B11/02 ,  G01N21/21

CPC classification number: G01J3/447 ,  G01B11/02 ,  G01B2210/56 ,  G01J3/0208 ,  G01J3/0224 ,  G01J3/42 ,  G01N21/21 ,  G01N2021/213 ,  G02B27/14 ,  G02B27/40

Abstract: Disclosed is a normal-incidence broadband spectroscopic polarimeter containing reference beam, comprising a light source, a first reflecting unit, a first concentrating unit, a second concentrating unit, a polarizer, a first curved mirror, a first planar mirror, a second reflecting unit and a probing unit. Also disclosed is an optical measurement system, comprising the normal-incidence broadband spectroscopic polarimeter containing reference beam. The normal-incidence broadband spectroscopic polarimeter containing reference beam achieves an integral combination of the light beams after splitting, can maintain the polarization state of the light beams while increasing the light transmission efficiency, and has a low complexity.

Abstract translation: 公开了一种包含参考光束的正常入射宽带分光偏振计，包括光源，第一反射单元，第一浓缩单元，第二浓缩单元，偏振器，第一曲面镜，第一平面镜，第二反射单元 和探测单元。 还公开了一种光学测量系统，其包括含有参考光束的正常入射宽带光谱偏振计。 含有参考光束的正常入射宽带光谱旋光仪实现了分光后的光束的整体组合，可以在提高光传输效率的同时保持光束的偏振态，并且具有较低的复杂度。