公开(公告)号：US5978074A

公开(公告)日：1999-11-02

申请号：US887865

申请日：1997-07-03

Applicant: Jon Opsal ,  Li Chen

Inventor： Jon Opsal ,  Li Chen

IPC: G01B11/06 ,  G01N21/17 ,  G01N21/21 ,  G01N21/27 ,  G01N21/00

CPC classification number: G01N21/1702 ,  G01N21/211

Abstract: An apparatus for characterizing multilayer samples is disclosed. An intensity modulated pump beam is focused onto the sample surface to periodically excite the sample. A probe beam is focused onto the sample surface within the periodically excited area. The power of the reflected probe beam is measured by a photodetector. The output of the photodetector is filtered and processed to derive the modulated optical reflectivity of the sample. Measurements are taken at a plurality of pump beam modulation frequencies. In addition, measurements are taken as the lateral separation between the pump and probe beam spots on the sample surface is varied. The measurements at multiple modulation frequencies and at different lateral beam spot spacings are used to help characterize complex multilayer samples. In the preferred embodiment, a spectrometer is also included to provide additional data for characterizing the sample.

公开(公告)号：US5877859A

公开(公告)日：1999-03-02

申请号：US685606

申请日：1996-07-24

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：US5181080A

公开(公告)日：1993-01-19

申请号：US813900

申请日：1991-12-23

Applicant: Jeffrey T. Fanton ,  Jon Opsal ,  Allan Rosencwaig

Inventor： Jeffrey T. Fanton ,  Jon Opsal ,  Allan Rosencwaig

IPC: G01B11/06

CPC classification number: G01B11/065

Abstract: A method and apparatus is disclosed for measuring the thickness or other optical constants of a thin film on a sample. The apparatus includes a laser for generating a linearly polarized probe beam. The probe beam is tightly focused on the sample surface to create a spread of angles of incidence. The reflected probe beam is passed through a quarter-wave plate and linear polarizer before impinging on a quad cell photodetector. The output signals from the photodetector represent an integration of the intensity of individual rays having various angles of incidence. By taking the difference between the sums of the output signals of diametrically opposed quadrants, a value can be obtained which varies linearly with film thickness for very thin films. The subject device can be used in conjunction with other prior devices to enhance sensitivity for thicker films.

Abstract translation: 公开了用于测量样品上的薄膜的厚度或其它光学常数的方法和装置。 该装置包括用于产生线偏振探测光束的激光器。 探针光束紧紧地聚焦在样品表面上以产生入射角的扩散。 反射的探测光束在撞击在四单元光电检测器上之前通过四分之一波片和线偏振器。 来自光电检测器的输出信号表示具有各种入射角的单个光线的强度的积分。 通过取直径相对的象限的输出信号的和之间的差值，可以获得与薄膜厚度线性变化的值。 本装置可以与其他现有装置一起使用，以增强较厚膜的灵敏度。

公开(公告)号：US5042951A

公开(公告)日：1991-08-27

申请号：US409393

申请日：1989-09-19

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

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

IPC: G01N21/21 ,  G03F7/20

CPC classification number: G03F7/70633 ,  G01N21/211

Abstract: In an ellipsometric apparatus, a laser is provided for generating a probe beam. The probe beam is passed through a polarization section to give the beam a known polarization state. The probe beam is then tightly focused with a high numerical aperture lens onto the surface of the sample. The polarization state of the reflected probe beam is analyzed. In addition, the angle of incidence of one or more rays in the incident probe beam is determined based the radial position of the rays within the reflected probe beam. This approach provides enhanced spatial resolution and allows measurement over a wide spread of angles of incidence without adjusting the position of the optical components. Multiple angle of incidence measurements are greatly simplified.

Abstract translation: 在椭圆仪器中，提供用于产生探针光束的激光器。 探测光束通过偏振部分，以使光束成为已知的偏振状态。 然后将探针光束与高数值孔径透镜紧密聚焦到样品的表面上。 分析反射探测光束的偏振状态。 此外，入射探测光束中的一个或多个射线的入射角是根据反射的探测光束内的射线的径向位置来确定的。 这种方法提供了增强的空间分辨率，并且允许在大范围的入射角度上进行测量，而不调整光学部件的位置。 多个入射角测量被大大简化。

公开(公告)号：US4632561A

公开(公告)日：1986-12-30

申请号：US728759

申请日：1985-04-30

Applicant: Allan Rosencwaig ,  Jon Opsal

Inventor： Allan Rosencwaig ,  Jon Opsal

IPC: G01N23/225 ,  G01N21/47 ,  G01N21/84 ,  G01N21/88 ,  G01N25/72

CPC classification number: G01N25/72 ,  G01N21/47 ,  G01N2021/1782 ,  G01N2021/8461 ,  G01N21/171

Abstract: A method and apparatus is disclosed for evaluating surface and subsurface features in a sample by detecting scattering of a probe beam. More particularly, the subject invention relates to the detection of thermal and/or plasma waves through the phenomenon of optical scattering. The apparatus includes a periodic excitation source for supplying energy to the surface of the sample to generate thermal and/or plasma waves. A radiation probe is directed to the surface of the sample within the area that is being periodically excited and in a manner that the probe beam is scattered from the excited area. Variations of the intensity of the scattered probe beam are detected and processed to evaluate surface and subsurface characteristics of the sample.

Abstract translation: 公开了一种通过检测探测光束的散射来评估样品中的表面和地下特征的方法和装置。 更具体地说，本发明涉及通过光散射现象检测热和/或等离子体波。 该装置包括用于向样品表面提供能量以产生热和/或等离子体波的周期性激发源。 辐射探针被引导到被周期性地激发的区域内的样品表面，并且以探针光束从激发区域散射的方式。 检测并处理散射探针光束强度的变化，以评估样品的表面和表面下特性。