公开(公告)号：US06778273B2

公开(公告)日：2004-08-17

申请号：US10112138

申请日：2002-03-29

Applicant: Adam E. Norton ,  Abdurrahman Sezginer ,  Fred E. Stanke

Inventor： Adam E. Norton ,  Abdurrahman Sezginer ,  Fred E. Stanke

IPC: G01J400

CPC classification number: G01B11/02 ,  G01J3/02 ,  G01J3/0294 ,  G01N21/211 ,  G01N21/25 ,  G01N21/474 ,  G01N21/9501 ,  G01N21/956 ,  G01N2021/213

Abstract: An optical measurement system for evaluating a sample has a azimuthally rotatable measurement head. A motor-driven rotating mechanism is coupled to the measurement head to allow the optics to rotate with respect to the sample. In particular, a preferred embodiment is a polarimetric scatterometer (FIG. 1) for measuring optical properties of a periodic structure on a wafer sample (12). This scatterometer has optics (30) directing a polarized illumination beam at non-normal incidence onto the periodic structure. In addition to a polarizer (8), the illumination path can also be provided with an E-O modulator for modulating the polarization. The measurement head optics also collect light reflected from the periodic structure and feed that light to a spectrometer (17) for measurement. A polarization beamsplitter (18) is provided in the collection path so that both S and P polarization from the sample can be separately measured. The entire measurement head can be mounted for rotation of the plane of incidence to different azimuthal directions relative to the periodic structures on the wafer. The instrument can be integrated within a wafer process tool in which wafers may be provided at arbitrary orientation.

Abstract translation: 用于评估样品的光学测量系统具有方位角可旋转的测量头。 马达驱动的旋转机构耦合到测量头以允许光学器件相对于样品旋转。 特别地，优选的实施例是用于测量晶片样品（12）上的周期性结构的光学性质的偏振散射仪（图1）。 该散射仪具有将非正常入射的偏振照明光束引导到周期性结构上的光学器件（30）。 除了偏振器（8）之外，照明路径还可以设置有用于调制偏振的E-O调制器。 测量头光学器件还收集从周期性结构反射的光并将该光馈送到用于测量的光谱仪（17）。 偏振分束器（18）设置在收集路径中，从而可以分别测量来自样本的S和P极化。 可以将整个测量头安装成相对于晶片上的周期性结构使入射平面旋转到不同的方位角方向。 仪器可以集成在晶片工艺工具中，其中可以以任意取向提供晶片。

公开(公告)号：US06667805B2

公开(公告)日：2003-12-23

申请号：US09932548

申请日：2001-08-17

Applicant: Adam E. Norton ,  Kenneth C. Johnson ,  Fred E. Stanke

Inventor： Adam E. Norton ,  Kenneth C. Johnson ,  Fred E. Stanke

IPC: G01J328

CPC classification number: G01N21/31 ,  G01J3/02 ,  G01J3/0224 ,  G01J3/0243 ,  G01J3/28 ,  G01N21/956 ,  G02B5/3083 ,  G02B27/28

Abstract: A small-spot imaging, spectrometry instrument for measuring properties of a sample has a polarization-scrambling element, such as a Lyot depolarizer, incorporated between the polarization-introducing components of the system, such as the beamsplitter, and the microscope objective of the system. The Lyot depolarizer varies polarization with wavelength. Sinusoidal perturbation in the resulting measured spectrum can be removed by data processing techniques or, if the depolarizer is thick or highly birefringent, may be narrower than the wavelength resolution of the instrument.

公开(公告)号：US5917594A

公开(公告)日：1999-06-29

申请号：US57245

申请日：1998-04-08

Applicant: Adam E. Norton

Inventor： Adam E. Norton

IPC: G01J4/04 ,  G01J3/02 ,  G01J3/42 ,  G01N21/21 ,  G01N21/27 ,  G01N21/47 ,  G02B17/08 ,  G01J3/447

CPC classification number: G01J3/02 ,  G01J3/0208 ,  G01J3/42 ,  G01N21/211 ,  G02B19/0028 ,  G02B19/0047 ,  G02B19/0095 ,  G01N21/47

Abstract: Achromatic optics may be employed in spectroscopic measurement systems. The achromatic optics comprises a spherical mirror receiving a beam of radiation in a direction away from its axis and a pair of lenses: a positive lens and a negative meniscus lens. The negative meniscus lens corrects for the spherical aberration caused by off-axis reflection from the spherical mirror. The positive lens compensates for the achromatic aberration introduced by the negative lens so that the optics, as a whole, is achromatic over visible and ultraviolet wavelengths. Preferably, the two lenses combined have zero power or close to zero power. By employing a spherical mirror, it is unnecessary to employ ellipsoidal or paraboloidal mirrors with artifacts of diamond turning which limit the size of the spot of the sample that can be measured in ellipsometry, reflectometry or scatterometry.

公开(公告)号：US5859424A

公开(公告)日：1999-01-12

申请号：US835533

申请日：1997-04-08

Applicant: Adam E. Norton ,  Kenneth C. Johnson ,  Joseph R. Carter

Inventor： Adam E. Norton ,  Kenneth C. Johnson ,  Joseph R. Carter

IPC: G01J4/04 ,  G01N21/21 ,  G01N21/27 ,  G02B27/58 ,  G03F7/20 ,  G01J3/50

CPC classification number: G03F7/70616 ,  G02B27/58

Abstract: Because of diffraction effects caused by slits or apertures in optical measurement systems, the radiation energy which is directed towards a particular region on a sample will be spread over a larger area than desirable. By employing an apodizing filter in the radiation path in such system, diffraction tails of the system will be reduced. The apodizing filter preferably has a pattern of alternating high transmittance areas and substantially opaque areas where the locally averaged transmittance function is an apodizing function. In the preferred embodiment, the locally averaged transmittance function varies smoothly and monotonically from the periphery to the center of the filter.

Abstract translation: 由于在光学测量系统中由狭缝或孔径引起的衍射效应，被引导到样品上的特定区域的辐射能量将扩展到比所需的更大的面积上。 通过在这种系统中的辐射路径中采用变迹滤波器，系统的衍射尾部将被减小。 变迹滤波器优选地具有交替的高透射率区域和基本上不透明区域的图案，其中局部平均透射率函数是变迹函数。 在优选实施例中，局部平均透射率函数从滤光器的周边到中心平滑且单调地变化。