公开(公告)号：US20130070234A1

公开(公告)日：2013-03-21

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: 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: 提供了一种倾斜入射宽带光谱旋光计，其易于调节焦点，消色差，保持偏振并且具有简单的结构。 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：US07999936B1

公开(公告)日：2011-08-16

申请号：US12417606

申请日：2009-04-02

Applicant: Guoguang Li ,  Abdul Rahim Forouhi ,  Erik Nackerud

Inventor： Guoguang Li ,  Abdul Rahim Forouhi ,  Erik Nackerud

IPC: G01N15/02

CPC classification number: G01N15/0205 ,  G01N21/4133 ,  G01N21/532

Abstract: The refractive index, extinction coefficient, size and density of fluid suspended particles are simultaneously determined by combined transmittance and scattering measurements. The scattering measurements are preferably angle selective to obtain additional information about the scattered light. A charge-coupled device is employed for its high sensitivity to low light intensity in measurement of scattered light in combination with a photodiode array employed for its high signal to noise ratio, which is beneficial in transmittance measurement. The scattered light may be measured in an angle selective fashion by use of a motorized aperture that is concentrically positioned with respect to the impinging beam axis and moveable along the impinging beam axis. An ellipsoidal mirror collects the scattered light that passes through the motorized aperture and focuses the scattered light towards the charge-coupled device.

Abstract translation: 流体悬浮颗粒的折射率，消光系数，尺寸和密度通过组合的透射率和散射测量值同时确定。 散射测量优选地是角度选择性的，以获得关于散射光的附加信息。 采用电荷耦合器件对散射光测量时的低光强度的高灵敏度，结合用于其高信噪比的光电二极管阵列，这对透射率测量是有益的。 可以通过使用相对于入射光束轴线同心定位并且沿撞击光束轴线移动的电动孔径以角度选择性方式测量散射光。 椭球镜收集通过电动孔径的散射光，并将散射光聚焦到电荷耦合器件。

公开(公告)号：US20100245819A1

公开(公告)日：2010-09-30

申请号：US12383864

申请日：2009-03-27

Applicant: Guoguang Li

Inventor： Guoguang Li

IPC: G01J3/447 ,  G01J4/00 ,  G01J3/28

CPC classification number: G01B11/0641 ,  G01J3/447 ,  G01N21/211 ,  G01N21/8422 ,  G01N2021/213

Abstract: A method and apparatus for convolving spectroscopic data with certain phase information for practicing phase-compensated sensitivity-enhanced spectroscopy (PCSES). PCSES uses a beam of radiation in a polarization state PSp from a source emitting at a plurality of wavelengths, and places in the beam a compensator capable of altering polarization state PSp by applying a delimited phase shift Δ between two orthogonal polarization axes of the radiation to restrict a finely-vibrating spectrum. A sample disposed in the beam after the compensator generates a response beam by reflection, transmission or even both. A polarization state PSa of the response beam is passed to a detector to determine a spectrum of the response beam. A first spectrum is collected when polarization states PSp, PSa and the compensator are in a first polarization-altering configuration and a second spectrum is collected when polarization states PSp, PSa and the compensator are in a second polarization-altering configuration. A phase-compensated spectrum is then derived from just the first and second spectra thereby allowing the user to undertake optical characterization, including the measurement of film thickness t and complex indices of refraction n, k of the sample with as few as just two polarization-altering configurations.

Abstract translation: 一种用于实现相位补偿灵敏度增强光谱（PCSES）的具有某些相位信息的光谱数据卷积的方法和装置。 PCSES使用来自发射多个波长的源的偏振状态PSp的辐射束，并且通过施加限定的相移＆amp; Dgr在光束中放置能够改变偏振状态PSp的补偿器; 在辐射的两个正交偏振轴之间限制细振动光谱。 在补偿器之后设置在光束中的样品通过反射，透射或甚至两者产生响应光束。 响应光束的偏振态PSa被传递到检测器以确定响应光束的光谱。 当极化状态PSp，PSa和补偿器处于第一偏振改变配置时收集第一光谱，并且当偏振态PSp，PSa和补偿器处于第二偏振改变配置时收集第二光谱。 然后，仅从第一和第二光谱导出相位补偿光谱，从而允许用户进行光学表征，包括测量膜厚度t和样品的复数折射率n，k，其中仅具有两个极化 - 改变配置

公开(公告)号：US07525672B1

公开(公告)日：2009-04-28

申请号：US11305449

申请日：2005-12-16

Applicant: Shuqiang Chen ,  Guoguang Li

Inventor： Shuqiang Chen ,  Guoguang Li

IPC: G01B11/24

CPC classification number: G01B11/02 ,  G01B11/22 ,  G01N21/4788

Abstract: Methods and apparatus for optical characterization based on symmetry-reduced 2-D RCWA calculations are provided. The invention is applicable to gratings having a grating reflection symmetry plane. A sample can be illuminated at normal incidence or at a non-zero angle of incidence such that the plane of incidence is parallel to or identical with the symmetry plane. The diffracted field components are either symmetric or anti-symmetric with respect to the grating symmetry plane. This symmetry is exploited to provide a symmetry-reduced 2-D RCWA having reduced matrix dimension (by about a factor of two) that is mathematically equivalent to a conventional 2-D RCWA. For normal incidence on a grating having two reflection symmetry planes, a symmetry-reduced 2-D RCWA having reduced matrix dimension (by about a factor of four) is provided. This normal incidence RCWA can be used to approximately characterize a sample illuminated at non-normal incidence. Approximation accuracy can be improved by modifying either the grating depth or the grating refractive index.

Abstract translation: 提供了基于对称减少的2-D RCWA计算的光学表征的方法和装置。 本发明适用于具有光栅反射对称面的光栅。 样品可以以正常入射或非零入射角照射，使得入射平面与对称平面平行或相同。 衍射场分量相对于光栅对称平面是对称的或反对称的。 这种对称性被用于提供在数学上等同于传统的2-D RCWA的具有减小的矩阵尺寸（大约二分之一）的对称减小的二维RCWA。 对于具有两个反射对称平面的光栅的正常入射，提供了具有减小的矩阵尺寸（约四分之一）的对称减小的二维RCWA。 这种正常发生率的RCWA可用于近似表征以非正常发生率照射的样本。 可以通过修改光栅深度或光栅折射率来提高近似精度。

公开(公告)号：US06982793B1

公开(公告)日：2006-01-03

申请号：US10116863

申请日：2002-04-04

Applicant: Weidong Yang ,  Roger R. Lowe-Webb ,  John D. Heaton ,  Guoguang Li

Inventor： Weidong Yang ,  Roger R. Lowe-Webb ,  John D. Heaton ,  Guoguang Li

IPC: G01B11/27

CPC classification number: G03F7/70633 ,  G03F9/7076

Abstract: An alignment target includes periodic patterns on two elements. The alignment target includes two locations, at least one of which has a designed in offset. In one embodiment, both measurement locations have a designed in offset of the same magnitude but opposite directions. For example, two separate overlay patterns that are mirror images of each other may be used. Alternatively, the magnitudes and/or directions may vary between the measurement locations. The radiation that interacts with the measurement locations is compared. The calculated difference is extremely sensitive to any alignment error. If the difference between the patterns is approximately zero, the elements are properly aligned. When an alignment error is introduced, however, calculated difference can be used to determine the error. In one embodiment, the alignment target is modeled to determine the alignment error. In another embodiment, additional overlay patterns with additional reference offsets are used to determine the alignment error.

Abstract translation: 对齐目标包括两个元素上的周期性图案。 对准目标包括两个位置，其中至少一个具有偏移设计。 在一个实施例中，两个测量位置具有相同幅度但相反方向偏移的设计。 例如，可以使用作为彼此的镜像的两个单独的覆盖图案。 或者，幅度和/或方向可以在测量位置之间变化。 比较与测量位置相互作用的辐射。 计算的差异对任何对准误差都非常敏感。 如果图案之间的差异大约为零，则元素将被正确对齐。 然而，当引入对准误差时，可以使用计算出的差异来确定误差。 在一个实施例中，对准目标被建模以确定对准误差。 在另一个实施例中，使用具有附加参考偏移的附加覆盖图案来确定对准误差。

公开(公告)号：US6091485A

公开(公告)日：2000-07-18

申请号：US464640

申请日：1999-12-15

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: G01N21/00

CPC classification number: G01N21/41 ,  G01N21/55 ,  G01N21/59

Abstract: A method and apparatus for optically determining a physical parameter of an underlayer such as the underlayer refractive index N.sub.u, extinction coefficient k.sub.u and/or thickness t.sub.u through a top layer having a first top layer thickness t.sub.1 and an assigned refractive index index n.sub.t and coefficient of extinction k.sub.t. The values of index n.sub.t and extinction coefficient k.sub.t can be estimated, optically determined or assigned based on prior knowledge. In a subsequent step a first reflectance R.sub.1 is measured over a wavelength range .DELTA..lambda. by using a test beam spanning that wavelength range. Then, a second reflectance R.sub.2 of the top layer and underlayer is measured using the test beam spanning wavelength range .DELTA..lambda. at a second top layer thickness t.sub.2. In a calculation step the physical parameter of the underlayer is determined from the first reflectance measurement R.sub.1, the second reflectance measurement R.sub.2, and the assigned or predetermined thickness values t.sub.1, t.sub.2, and the refractive index n.sub.t. and coefficient of extinction k.sub.t of the top layer. A dispersion model can be used in this calculation step. Alternatively, with transmissive samples, a first and second transmittance T.sub.1, T.sub.2 can be used.

Abstract translation: 一种用于通过具有第一顶层厚度t1和所分配的折射率指数nt的顶层以及所分配的折射率指数nt和的系数来光学地确定诸如底层折射率Nu，消光系数ku和/或厚度tu的底层的物理参数的方法和装置 灭绝kt 指数nt和消光系数kt的值可以基于现有知识来估计，光学确定或分配。 在随后的步骤中，通过使用横跨该波长范围的测试光束，在波长范围DELTAλ上测量第一反射率R1。 然后，使用第二顶层厚度t2的跨越波长范围DELTAλ的测试光束来测量顶层和底层的第二反射率R2。 在计算步骤中，从第一反射率测量R1，第二反射率测量R2和分配的或预定的厚度值t1，t2和折射率nt确定底层的物理参数。 和顶层消光系数kt。 在该计算步骤中可以使用色散模型。 或者，对于透射样品，可以使用第一和第二透射率T1，T2。