Source: http://www.google.com/patents/US7312877?dq=6106459
Timestamp: 2013-12-19 13:29:07
Document Index: 664484029

Matched Legal Cases: ['Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60']

Patent US7312877 - Method and apparatus for enhanced resolution of high spatial frequency ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA method of measuring properties of a substrate, the method involving: illuminating a spot on the substrate with a standing wave measurement beam to generate a return measurement beam, the standing wave measurement beam characterized by a standing wave pattern; generating an electrical signal from the...http://www.google.com/patents/US7312877?utm_source=gb-gplus-sharePatent US7312877 - Method and apparatus for enhanced resolution of high spatial frequency components of images using standing wave beams in non-interferometric and interferometric microscopyAdvanced Patent SearchPublication numberUS7312877 B2Publication typeGrantApplication numberUS 10/954,625Publication dateDec 25, 2007Filing dateSep 30, 2004Priority dateOct 1, 2003Fee statusLapsedAlso published asUS20050206909, WO2005033747A2, WO2005033747A3Publication number10954625, 954625, US 7312877 B2, US 7312877B2, US-B2-7312877, US7312877 B2, US7312877B2InventorsHenry Allen HillOriginal AssigneeZetetic InstituteExport CitationBiBTeX, EndNote, RefManPatent Citations (57), Non-Patent Citations (20), Referenced by (2), Classifications (11), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetMethod and apparatus for enhanced resolution of high spatial frequency components of images using standing wave beams in non-interferometric and interferometric microscopyUS 7312877 B2Abstract A method of measuring properties of a substrate, the method involving: illuminating a spot on the substrate with a standing wave measurement beam to generate a return measurement beam, the standing wave measurement beam characterized by a standing wave pattern; generating an electrical signal from the return measurement beam; causing the standing wave pattern to be at a succession of different positions on the surface of the substrate; and for each of the succession of different positions of the standing wave pattern, acquiring measurement data from the electrical signal.
BACKGROUND OF THE INVENTION A number of different applications of catadioptric imaging systems for far-field and near-field interferometric confocal and non-confocal microscopy have been described such as in commonly owned U.S. Pat. No. 6,552,852 (ZI-38) entitled �Catoptric And Catadioptric Imaging Systems� and U.S. Pat. No. 6,717,736 (ZI-43) entitled �Catoptric And Catadioptric Imaging Systems;� U.S. Provisional Patent Applications No. 60/447,254, filed Feb. 13, 2003, entitled �Transverse Differential Interferometric Confocal Microscopy,� (ZI-40); No. 60/448,360, filed Feb. 19, 2003, entitled �Longitudinal Differential Interferometric Confocal Microscopy for Surface Profiling,� (ZI-41); No. 60/448,250, filed Feb. 19, 2003, entitled �Method and Apparatus for Dark Field Interferometric Confocal Microscopy,� (ZI-42); No. 60/442,982, filed Jan. 28, 2003, entitled �Interferometric Confocal Microscopy Incorporating Pinhole Array Beam-Splitter,� (ZI-45); No. 60/459,425, filed Apr. 1, 2003, entitled �Apparatus and Method for Joint Measurement Of Fields Of Scattered/Reflected Orthogonally Polarized Beams By An Object In Interferometry,� (ZI-50); No. 60/485,507, filed Jul. 7, 2003, entitled �Apparatus And Method For High Speed Scan For Sub-Wavelength Defects And Artifacts In Semiconductor Metrology,� (ZI-52); No. 60/485,255, filed Jul. 7, 2003, entitled �Apparatus and Method for Ellipsometric Measurements with High Spatial Resolution,� (ZI-53); No. 60/501,666, filed Sep. 10, 2003, entitled �Catoptric And Catadioptric Imaging Systems With Adaptive Catoptric Surfaces,� (ZI-54); No. 60/602,046, filed Aug. 16, 2004, entitled �Apparatus And Method For Joint And Time Delayed Measurements Of Components Of Conjugated Quadratures Of Fields Of Reflected/Scattered Beams By An Object In Interferometry,� (ZI-57); No. 60/506,715, filed Sep. 26, 2003, entitled �Catoptric and Catadioptric Imaging Systems Comprising Pellicle Beam-Splitters and Non-Adaptive and Adaptive Catoptric Surfaces,� (ZI-56); and No. 60/611,564, filed Sep. 20, 2004, entitled �Catoptric Imaging Systems Comprising Pellicle Beam-Splitters and Non-Adaptive and/or Adaptive Catoptric Surfaces,� (ZI-58); and U.S. patent application Ser. No. 10/778,371, filed Feb. 13, 2004, entitled �Transverse Differential Interferometric Confocal Microscopy,� (ZI-40); Ser. No. 10/782,057, filed Feb. 19, 2004, entitled �Longitudinal Differential Interferometric Confocal Microscopy for Surface Profiling,� (ZI-41); Ser. No. 10/782,058, filed Feb. 19, 2004, entitled �Method and Apparatus for Dark Field Interferometric Confocal Microscopy,� (ZI-42); Ser. No. 10/765,229, filed Jan. 27, 2004, entitled �Interferometric Confocal Microscopy Incorporating Pinhole Array Beam-Splitter,� (ZI-45); Ser. No. 10/816,180, filed Apr. 1, 2004, entitled �Apparatus and Method for Joint Measurement Of Fields Of Scattered/Reflected or Transmitted Orthogonally Polarized Beams By An Object In Interferometry,� (ZI-50); Ser. No. 10/886,010, filed Jul. 7, 2004, entitled �Apparatus And Method For High Speed Scan For Sub-Wavelength Defects And Artifacts In Semiconductor Metrology,� (ZI-52); Ser. No. 10/886,157, filed Jul. 7, 2004, entitled �Apparatus and Method for Ellipsometric Measurements with High Spatial Resolution,� (ZI-53); No. 10/938,408, filed Sep. 10, 2004, entitled �Catoptric And Catadioptric Imaging Systems With Adaptive Catoptric Surfaces,� (ZI-54); No. 10/948,959, filed Sep. 24, 2004, entitled �Catoptric and Catadioptric Imaging Systems with Pellicle and Aperture-Array Beam-Splitters and Non-Adaptive and Adaptive Catoptric Surfaces�. In addition, U.S. patent application (ZI-48) Ser. No. 10/218,201, entitled �Method for Constructing a Catadioptric Lens System,� filed Apr. 1, 2004 described one way to make some of these catadioptric lens systems. These patents, patent applications, and provisional patent applications are all by Henry A. Hill and the contents of each are incorporated herein in their entirety by reference.
SUMMARY OF THE INVENTION Methods and apparatuses are described for achieving enhanced resolution of high spatial frequency components of images generated in non-interferometric microscopy using standing wave illumination of a substrate and in interferometric microscopy using a standing wave reference beam and/or standing wave measurement beam and wherein a measurement object may also be used simultaneously as a reference object. The enhanced resolution is achieved in microscopy systems operating in either a reflection or a transmission mode. The resolution for the high spatial frequency components is enhanced by approximately a factor of 2 in one dimension or two orthogonal dimensions with respect to that achievable in other imaging systems.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 a is a schematic diagram of an interferometric system operating in a reflection mode configured with a standing wave measurement beam at a measurement object.
DETAILED DESCRIPTION A general description of interferometric microscopy embodiments of the present invention will first be given. The interferometric microscopy embodiments are separated into groups according to properties of a measurement beam incident on an object or substrate; to whether the substrate is used as both the measurement and reference beam objects simultaneously or only as a measurement beam object; and to properties of a reference beam incident on a beam combining element, e.g., a beam-splitter.
The description of source 18 including a pulse mode of operation and beam-conditioner 22 is the same as the corresponding portions of the description given to the source and beam-conditioner in embodiments described in commonly owned U.S. Provisional Patent Application No. 60/442,858 (ZI-47) entitled �Apparatus and Method for Joint Measurements of Conjugated Quadratures of Fields of Reflected/Scattered Beams by an Object in Interferometry� and U.S. patent application Ser. No. 10/765,368 (ZI-47) entitled �Apparatus and Method for Joint Measurements of Conjugated Quadratures of Fields of Reflected/Scattered or Transmitted Beams by an Object in Interferometry� wherein the provisional and the non-provisional patent applications are by Henry A. Hill and the contents of which are herein incorporated in their entirety by reference and in cited U.S. Provisional Patent Application No. 60/485,255 (ZI-53), in cited U.S. Provisional Patent Ser. No. 60/602,046 filed Aug. 16, 2004 (ZI-57) entitled �Apparatus and Method for Joint And Time Delayed Measurements of Components of Conjugated Quadratures of Fields of Reflected/Scattered and Transmitted/Scattered Beams by an Object in Interferometry,� and in cited U.S. patent application Ser. No. 60/485,255 filed Jul. 7, 2003 (ZI-53) entitled �Apparatus and Method for Ellipsometric Measurements with High Spatial Resolution.�
The extension of the bi- and quad-homodyne detection methods to N-dimensional bi- and quad-homodyne detection methods may also be based on a combination of frequency encoding, polarization encoding, and either amplitude or phase modulations or permutations. The description of bi- and quad-homodyne detection methods based on a combination of frequency and polarization encoding is the same as the corresponding description given in cited U.S. Provisional Patent Application No. 60/459,425 (ZI-50) and in cited U.S. patent application Ser. No. 60/459,425 filed Apr. 1, 2003 (ZI-50) entitled �Apparatus and Method for Joint Measurement Of Fields Of Orthogonally Polarized Beams Scattered/Reflected By An Object In Interferometry.�
The description of interferometer 10, source 18, beam-conditioner 22, detector 70, and electronic processor and controller 80 is the same as corresponding portions of the descriptions of catoptric and catadioptric imaging systems given in commonly owned U.S. Patent Provisional Patent Application No. 60/506,715 (ZI-56) entitled �Catoptric and Catadioptric Imaging Systems Comprising Pellicle Beam-Splitters And Non-Adaptive And Adaptive Catoptric Surfaces� by Henry A. Hill, David Fischer, and Steven Hamann; in cited U.S. Provisional Patent Application Ser. No. 60/602,046 filed Aug. 16, 2004 (ZI-57) entitled �Apparatus and Method for Joint And Time Delayed Measurements of Components of Conjugated Quadratures of Fields of Reflected/Scattered and Transmitted/Scattered Beams by an Object in Interferometry�; and in U.S. patent application Ser. No. 60/506,715 filed Sep. 26, 2003 (ZI-56) entitled �Catoptric and Catadioptric Imaging Systems Comprising Pellicle Beam-Splitters And Non-Adaptive And Adaptive Catoptric Surfaces� by Henry A. Hill, David Fischer, and Steven Hamann for which the contents of the first of the two provisional patent applications and the utility patent application are incorporated herein in their entirety by reference.
A number of different catadioptric imaging systems for far-field and near-field interferometric confocal microscopy have been described such as in commonly owned U.S. Pat. No. 6,552,852 (ZI-38) entitled �Catoptric And Catadioptric Imaging Systems;� U.S. Pat. No. 6,717,736 (ZI-43) entitled �Catoptric And Catadioptric Imaging Systems;� U.S. Provisional Patent Applications No. 60/447,254 (ZI-40) entitled �Transverse Differential Interferometric Confocal Microscopy,� No. 60/448,360 (ZI-41) entitled �Longitudinal Differential Interferometric Confocal Microscopy,� No. 60/448,250 (ZI-42) entitled �Thin Film Metrology Using Interferometric Confocal Microscopy,� No. 60/442,982 (ZI-45) entitled �Interferometric Confocal Microscopy Incorporating Pinhole Array Beam-Splitter,� No. 60/459,493 (ZI-48) entitled �Method For Manufacture Of Catadioptric Lens System,� No. 60/459,425 (ZI-50) entitled �Apparatus and Method for Joint Measurement Of Fields Of Orthogonally Polarized Beams Scattered/Reflected By An Object In Interferometry,� in cited No. 60/485,255 (ZI-53), No. 60/501,666 (ZI-54) entitled �Catoptric and Catadioptric Imaging Systems With Adaptive Catoptric Surfaces,� and filed Sep. 18, 2004 (ZI-58) entitled �Catoptric Imaging Systems Comprising Pellicle and/or Aperture-Array Beam-Splitters and Non-Adaptive and/or Adaptive Catoptric Surfaces;� and U.S. patent application Ser. No. 10/778,371 (ZI-40) entitled �Transverse Differential Interferometric Confocal Microscopy,� Ser. No. 10/782,057 (ZI-41) entitled �Longitudinal Differential Interferometric Confocal Microscopy,� Ser. No. 10/782,058 (ZI-42) entitled �Thin Film Metrology Using Interferometric Confocal Microscopy,� Ser. No. 10/765,229 (ZI-45) entitled �Interferometric Confocal Microscopy Incorporating Pinhole Array Beam-Splitter,� Ser. No. 10/816,201 (ZI-48) entitled �Method For Manufacture Of Catadioptric Lens System,� Ser. No. 10/816,180 (ZI-50) entitled �Apparatus and Method for Joint Measurement Of Fields Of Orthogonally Polarized Beams Scattered/Reflected By An Object In Interferometry,� in cited patent application Ser. No. 60/485,255 filed Jul. 7, 2003 (ZI-53) entitled �Apparatus and Method for Ellipsometric Measurements with High Spatial Resolution,� and aplication Ser. No. 60/501,666 filed Sep. 10, 2003 (ZI-54) entitled �Catoptric and Catadioptric Imaging Systems With Adaptive Catoptric Surfaces.� The two cited patents, the seven not previously cited patent applications, and the eight not previously cited provisional patent applications are all by Henry A. Hill and the contents of each of which are incorporated herein in their entirety by reference. Other forms of non-catoptric or non-catadioptric microscopy imaging systems may be used for interferometer 10 without departing from the spirit or scope of the present invention.
θ1 π−θ1. (1)The description of the reference beam and measurement beam properties at a beam combining element in interferometer 10 when comprising standing wave beams is the same as corresponding portions of the description given for FIGS. 1 g-1 k. Properties of Electric Fields Associated with Incident Beams
E p ( 1 ) = { 2 ⁢ E p , 0 ( 1 ) ⁡ [ ix ⁢ ⁢ cos ⁢ ⁢ θ 1 ⁢ sin ⁡ ( k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁢ x ) + z ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁢ cos ⁡ ( k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁢ x ) ] ⁢ ⅇ - ⅈ ⁢ ⁢ k ⁢ ⁢ cos ⁢ ⁢ θ 1 ⁢ z , z ≥ 0 , 2 ⁢ E p , 0 ′ ⁡ ( 1 ) ⁡ [ ix ⁢ ⁢ cos ⁢ ⁢ θ 1 ′ ⁢ sin ⁡ ( kn ′ ⁢ sin ⁢ ⁢ θ 1 ′ ⁢ x ) + z ⁢ ⁢ sin ⁢ ⁢ θ 1 ′ ⁢ cos ⁡ ( kn ′ ⁢ sin ⁢ ⁢ θ 1 ′ ⁢ x ) ] ⁢ ⅇ - ⅈ ⁢ ⁢ kn ′ ⁢ cos ⁢ ⁢ θ 1 ′ ⁢ z ⁢ ⅇ k ⁢ ⁢ κ ′ ⁢ z ⁢ ⁢ sec ⁢ ⁢ θ 1 ′ , z < 0 , ( 2 ) where Ep,0 (1) and E′p,0 r(1) are the amplitudes of the electric field component of the incident and refracted beams, respectively, n1′ and κ′ are the real and imaginary components of the complex refractive index for z<0, θ′ is the angle of refraction of the beam, i=√{square root over ((−1))}, λ is the wavelength for the two beams and wavenumber k=2π/λ, and x and z are a unit vectors in the x- and z-directions, respectively. The relative amplitudes E′p,0 r(1)/Ep,0 (1) can be found for example in Section 7.3 of the book by J. D. Jackson entitled Classical Electrodynamics (Wiley, Second Edition). The time dependence exp[iωt] of Ep (1) has been suppressed in Equation (2) and in subsequent equations where ω is the angular frequency of the beams.
E s ( 2 ) = { 2 ⁢ E s , 0 ( 2 ) ⁡ [ x ⁢ ⁢ cos ⁢ ⁢ ( k ⁢ ⁢ sin ⁢ ⁢ θ 2 ⁢ y ) ] ⁢ ⅇ - ⅈ ⁢ ⁢ k ⁢ ⁢ cos ⁢ ⁢ θ 2 ⁢ z , z ≥ 0 , 2 ⁢ E s , 0 ( 2 ) ⁡ [ x ⁢ ⁢ cos ⁢ ⁢ ( kn ′ ⁢ sin ⁢ ⁢ θ 2 ′ ⁢ y ) ] ⁢ ⅇ - ⅈ ⁢ ⁢ kn ′ ⁢ cos ⁢ ⁢ θ 2 ′ ⁢ z ⁢ ⅇ k ⁢ ⁢ κ ′ ⁢ z ⁢ ⁢ sec ⁢ ⁢ θ 2 ′ , z < 0. ( 3 ) where Es,0 (2) and E′s,0 r(2) are the amplitudes of the electric field component of the incident and refracted beams, respectively, and θ2 is the angle of incidence of the two beams. The relative amplitudes E′s,0 r(2)/Es,0 (2) can be found for example in cited Section 7.3 of the book by Jackson.
E p ( 2 ) = { 2 ⁢ E p , 0 ( 2 ) ⁡ [ iy ⁢ ⁢ cos ⁢ ⁢ θ 2 ⁢ sin ⁡ ( k ⁢ ⁢ sin ⁢ ⁢ θ 2 ⁢ y ) + z ⁢ ⁢ sin ⁢ ⁢ θ 2 ⁢ cos ⁡ ( k ⁢ ⁢ sin ⁢ ⁢ θ 2 ⁢ y ) ] ⁢ ⅇ - ⅈ ⁢ ⁢ k ⁢ ⁢ cos ⁢ ⁢ θ 2 ⁢ z , z ≥ 0 , 2 ⁢ E p , 0 ′ ⁡ ( 2 ) ⁡ [ iy ⁢ ⁢ cos ⁢ ⁢ θ 2 ′ ⁢ sin ⁡ ( kn ′ ⁢ sin ⁢ ⁢ θ 2 ′ ⁢ y ) + z ⁢ ⁢ sin ⁢ ⁢ θ 2 ′ ⁢ cos ⁡ ( kn ′ ⁢ sin ⁢ ⁢ θ 2 ′ ⁢ y ) ] ⁢ ⅇ - ⅈ ⁢ ⁢ kn ′ ⁢ cos ⁢ ⁢ θ 2 ′ ⁢ z ⁢ ⅇ k ⁢ ⁢ κ ′ ⁢ z ⁢ ⁢ sec ⁢ ⁢ θ 2 ′ , z < 0 , ( 4 ) where Ep,0 (2) and E′p,0 r(2) are the amplitudes of the electric field component of the incident and refracted beams, respectively,
E s ( 1 ) = { 2 ⁢ E s , 0 ( 1 ) ⁡ [ y ⁢ ⁢ cos ⁢ ⁢ ( k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁢ x ) ] ⁢ ⅇ - ⅈ ⁢ ⁢ k ⁢ ⁢ cos ⁢ ⁢ θ 1 ⁢ z , z ≥ 0 , 2 ⁢ E s , 0 ′ ⁡ ( 1 ) ⁡ [ y ⁢ ⁢ cos ⁢ ⁢ ( kn ′ ⁢ sin ⁢ ⁢ θ 1 ′ ⁢ x ) ] ⁢ ⅇ - ⅈ ⁢ ⁢ kn ′ ⁢ cos ⁢ ⁢ θ 1 ′ ⁢ z ⁢ ⅇ k ⁢ ⁢ κ ′ ⁢ z ⁢ ⁢ sec ⁢ ⁢ θ 1 ′ , z < 0. ( 5 ) The description of the measurement beam electric fields in FIGS. 1 j and 1 k are the same as the description of the measurement beam electric fields in FIGS. 1 h and 1 i, respectively.
δ ⁢ ⁢ S 1 ⁡ ( x , x ′ , y , y ′ , Δ ⁢ ⁢ z ) = 8 ⁢ CR ⁡ ( x , y ) ⁢ E p , 0 ( 1 ) ⁢ E p , 0 ( 2 ) � sin ⁢ ⁢ θ 1 ⁢ cos ⁡ ( k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁢ x ) ⁢ sin ⁢ ⁢ c ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ x , 0 ⁡ ( x - x ′ ) ] � sin ⁢ ⁢ θ 2 ⁢ cos ⁡ ( k ⁢ ⁢ sin ⁢ ⁢ θ 2 ⁢ y ) ⁢ sin ⁢ ⁢ c ⁢ ⁢ ⁢ [ ⁢ k ⁢ ⁢ sin ⁢ ⁢ θ y , 0 ⁡ ( y - y ′ ) ] � δ ⁢ ⁢ V ⁢ ⁢ cos ⁡ [ φ 1 , 2 + φ + k ⁡ ( cos ⁢ ⁢ θ 1 - cos ⁢ ⁢ θ 2 ) ⁢ Δ ⁢ ⁢ z ] ( 6 ) where the infinitesimal element of substrate 60 is located at (x, y, z=0), x′ and y′ are coordinates in the image space of the imaging system, δV is the infinitesimal volume of the infinitesimal element, R(x, y) is the reflection/scattering coefficient for the infinitesimal element, sin θx,0 and sin θy,0 represent the numerical aperture of the imaging system in the x and y directions, respectively, Δz is the displacement of the surface of substrate 60 from z=0, phase φ is the phase between measurement and reference beams determined by beam conditioner 22 or interferometer 10 as controlled by electronic processor and controller 80, phase φ1,2 is the phase between the reflected/scattered reference and measurement beam components of beam 32 for φ=0, and C is a proportionality constant.
R x ′ ≅ λ 2 ⁢ sin ⁢ ⁢ θ x , 0 , ( 7 ) R y ′ ≅ λ 2 ⁢ ⁢ sin ⁢ ⁢ θ y , 0 . ( 8 ) However, if the properties of δS1 given by Equation (6) are examined as a function of x or y, the inferred resolution Rx and Ry of the imaging system in the x′ and y′ directions, respectively, are different from Rx′ and Ry′, respectively, given by Equations (7) and (8). For the discussion of the resolutions Rx and Ry, the contributions to the electrical interference signal δS2 of two equal infinitesimal volume elements located in the surface of substrate 60 are examined. For the two infinitesimal volume elements located at x�Δx, the corresponding δS2 is
δ ⁢ ⁢ S 2 ⁡ ( x , x ′ , y , y ′ , Δ ⁢ ⁢ z ) = 8 ⁢ CR ⁡ ( x , y ) ⁢ E p , 0 ( 1 ) ⁢ E p , 0 ( 2 ) � sin ⁢ ⁢ θ 1 ⁢ { cos ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁡ ( x + Δ ⁢ ⁢ x ) ] ⁢ sin ⁢ ⁢ c ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ x , 0 ⁡ ( x - x ′ + Δ ⁢ ⁢ x ) ] + cos ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁡ ( x - Δ ⁢ ⁢ x ) ] ⁢ sin ⁢ ⁢ c ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ x , 0 ⁡ ( x - x ′ - Δ ⁢ ⁢ x ) ] } � sin ⁢ ⁢ θ 2 ⁢ cos ⁡ ( k ⁢ ⁢ sin ⁢ ⁢ θ 2 ⁢ y ) ⁢ sin ⁢ ⁢ c ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ y , 0 ⁡ ( y - y ′ ) ] � δ ⁢ ⁢ V ⁢ ⁢ cos ⁡ [ φ 1 , 2 + φ + k ⁡ ( cos ⁢ ⁢ θ 1 - cos ⁢ ⁢ θ 2 ) ⁢ Δ ⁢ ⁢ z ] ( 9 ) where it has been assumed that R(x,y) and φ1,2 are the same for the two infinitesimal volume elements for the purposes of simplifying the discussion without loss of important properties. The dependence of δS2 on x is determined by the factor �(x,x′,Δx) where
f ⁡ ( x , x ′ , Δ ⁢ ⁢ x ) = + { cos ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁡ ( x + Δ ⁢ ⁢ x ) ] ⁢ sin ⁢ ⁢ c ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ x , 0 ⁡ ( x - x ′ + Δ ⁢ ⁢ x ) ] + cos ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁡ ( x - Δ ⁢ ⁢ x ) ] ⁢ sin ⁢ ⁢ c ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ x , 0 ⁡ ( x - x ′ - Δ ⁢ ⁢ x ) ] } . ( 10 ) Function �(x,x′,Δx) is shown in FIG. 1 l as a function of x for different values of Δx, i.e. (Δx sin θ1/λ)=0, π/4, π/2, for the case of sin θ1=sin θx,0.
R x ≅ λ 4 ⁢ sin ⁢ ⁢ θ x , 0 . ( 11 ) The lateral resolution Ry is determined by a similar analysis to be accordingly
R y ≅ λ 4 ⁢ sin ⁢ ⁢ θ y , 0 . ( 12 ) The lateral resolutions Rx and Ry expressed by Equations (11) and (12) are smaller by a factor of 2 than the lateral resolutions Rx′ and Ry′, respectively, expressed by Equations (7) and (8), respectively. Thus the lateral spatial resolution is enhanced by a factor of approximately 2 when using standing wave reference and measurement beams at the measurement object and the reference and measurement objects are the same object simultaneously and by using a data acquisition procedures and analysis of the measured conjugated quadratures based on object space coordinates, i.e. x instead of x′ and y instead of y′.
δ ⁢ ⁢ I 1 ⁡ ( x , x ′ ) = 4 ⁢ CR ⁡ ( x , y ) ⁢ δ ⁢ ⁢ V ⁡ [ E s , 0 ( 1 ) ] 2 � sin ⁡ ( k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁢ x ) ⁢ sin ⁢ ⁢ c 2 ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ x , 0 ⁡ ( x - x ′ ) ] , ( 13 ) δ ⁢ ⁢ I 2 ⁡ ( x , x ′ ) = 4 ⁢ CR ⁡ ( x , y ) ⁢ δ ⁢ ⁢ V ⁡ ( E p , 0 ( 1 ) ) 2 � { cos ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁡ ( x + Δ ⁢ ⁢ x ) ] sin ⁢ ⁢ c ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ x , 0 ⁡ ( x - x ′ + Δ ⁢ ⁢ x ) ] + cos ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ 1 ⁡ ( x - Δ ⁢ ⁢ x ) ] sin ⁢ ⁢ c ⁡ [ k ⁢ ⁢ sin ⁢ ⁢ θ x , 0 ⁡ ( x - x ′ - Δ ⁢ ⁢ x ) ] } 2 . ( 14 ) The dependence of δI2 on x is determined by the factor [�(x,x′,Δx)]2 where �(x,x′,Δx) is given by Equation (10). Function [�(x,x′,Δx)]2 is shown in FIG. 1 m as a function of x for different values of Δx, i.e. (Δx sin θ1/λ)=0,θ/4,π/2, for the case of sin θ1=sin θx,0.
It is evident on inspection of Equations (2) and (5) for the z<0 solutions that the spatial properties of Ep (1) and ES (1) for z<0 are the same as those of standing evanescent fields propagating in the same region, i.e. exponentially decaying solutions. It is important to note that the respective spatial properties are generated advantageously with a relatively large working distance, e.g., of the order of mm's, as compared to the disadvantage of having a working distance of �λ/4 generally required in the generation and coupling of the evanescent fields into a refractive medium (see cited book by Jackson). This is a particularly important advantage when profiling a surface of a substrate with a large spot, e.g. �mm2, simultaneously, where the surface under examination is not flat to {tilde under (<)}λ/8. Also, the magnitude of the damping term in the refractive medium may be selected in part by the selection of the wavelength λ of the measurement beam.
The amplitudes of a standing wave reference beam and/or a standing wave measurement beam at the spots may by increased by the incorporation of a build up cavity or resonant cavity at substrate 60 and/or the beam combining element such as described in commonly owned U.S. Provisional Patent Application No. 60/221,091 (ZI-18) entitled �Multiple-Source Arrays with Optical Transmission Enhanced by Resonant Cavities� and U.S. patent application Ser. No. 09/917,400 (ZI-18) entitled �Multiple-Source Arrays with Optical Transmission Enhanced by Resonant Cavities� for which both are by Henry A. Hill and the contents of which are herein incorporated in their entirety by reference. An example of a resonant cavity is shown in FIG. 8 a of the cited U.S. Provisional Patent Application No. 60/221,091 and U.S. patent application Ser. No. 09/917,400.
An example of an interferometer 10 is shown diagrammatically in FIG. 2 a which comprises a catadioptric imaging system 410A shown schematically in FIG. 2 b with catoptric elements comprising adaptive reflective surfaces and with a pellicle beam-splitter. Except with respect to the description of the respective measurement beams, the description of interferometer 10 and catadioptric imaging system 410A of FIGS. 2 a and 2 b is the same as corresponding portions of the description given for interferometer 10 and catadioptric imaging system 410A in FIGS. 4 a and 4 b of cited U.S. Provisional Patent Application No. 60/506,715 (ZI-56) and U.S. patent application Ser. No. 60/506,715 filed Sep. 24, 2004 entitled �Catoptric and Catadioptric Imaging Systems Comprising Pellicle Beam-Splitters And Non-Adaptive And Adaptive Catoptric Surfaces.�
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS3628027Dec 17, 1969Dec 14, 1971Sulzer AgBeam deflecting and focusing means for photoelectric monitoring, counting or control apparatusUS3748015Jun 21, 1971Jul 24, 1973Perkin Elmer CorpUnit power imaging catoptric anastigmatUS4011011Dec 19, 1974Mar 8, 1977The Perkin-Elmer CorporationOptical projection apparatusUS4226501Oct 12, 1978Oct 7, 1980The Perkin-Elmer CorporationFour mirror unobscurred anastigmatic telescope with all spherical surfacesUS4272684Oct 6, 1978Jun 9, 1981Xerox CorporationOptical beam-splitting arrangements on object side of a lensUS4685803Jan 23, 1986Aug 11, 1987Zygo CorporationMethod and apparatus for the measurement of the refractive index of a gasUS4733967Mar 19, 1987Mar 29, 1988Zygo CorporationApparatus for the measurement of the refractive index of a gasUS5220403Sep 30, 1992Jun 15, 1993International Business Machines CorporationApparatus and a method for high numerical aperture microscopic examination of materialsUS5241423Aug 1, 1991Aug 31, 1993International Business Machines CorporationHigh resolution reduction catadioptric relay lensUS5327223Jun 19, 1992Jul 5, 1994International Business Machines CorporationMethod and apparatus for generating high resolution optical imagesUS5485317Oct 8, 1993Jan 16, 1996Solari Udine S.P.A.Optical system for light emitting diodesUS5508801 *Oct 5, 1993Apr 16, 1996Kabushikigaisya HutechMethod and apparatus for nondestructive testing of the mechanical behavior of objects under loading utilizing wave theory of plastic deformationUS5602643Feb 7, 1996Feb 11, 1997Wyko CorporationMethod and apparatus for correcting surface profiles determined by phase-shifting interferometry according to optical parameters of test surfaceUS5614763Mar 13, 1995Mar 25, 1997Zetetic InstituteMethods for improving performance and temperature robustness of optical coupling between solid state light sensors and optical systemsUS5633972Nov 29, 1995May 27, 1997Trustees Of Tufts CollegeSuperresolution imaging fiber for subwavelength light energy generation and near-field optical microscopyUS5659420Sep 30, 1994Aug 19, 1997Kabushiki Kaisha Komatsu SeisakushoConfocal optical apparatusUS5666197 *Aug 21, 1996Sep 9, 1997Polaroid CorporationApparatus and methods employing phase control and analysis of evanescent illumination for imaging and metrology of subwavelength lateral surface topographyUS5699201Mar 27, 1995Dec 16, 1997Hewlett-Packard Co.Low-profile, high-gain, wide-field-of-view, non-imaging opticsUS5757493Oct 16, 1996May 26, 1998Tropel CorporationInterferometer with catadioptric imaging system having expanded range of numerical apertureUS5760901Jan 28, 1997Jun 2, 1998Zetetic InstituteMethod and apparatus for confocal interference microscopy with background amplitude reduction and compensationUS5828455Mar 7, 1997Oct 27, 1998Litel InstrumentsApparatus, method of measurement, and method of data analysis for correction of optical systemUS5894195May 3, 1996Apr 13, 1999Mcdermott; KevinElliptical axial lighting deviceUS5915048Jun 5, 1996Jun 22, 1999Zetetic InstituteMethod and apparatus for discriminating in-focus images from out-of-focus light signals from background and foreground light sourcesUS6011654Sep 2, 1997Jan 4, 2000Carl-Zeiss-StiftungOptical arrangement for several individual beams with a segmented mirror fieldUS6052231Jan 19, 1999Apr 18, 2000International Business Machines CorporationBeam dividing elements permitting projection of an image with high contrastUS6091496Jun 2, 1998Jul 18, 2000Zetetic InstituteMultiple layer, multiple track optical disk access by confocal interference microscopy using wavenumber domain reflectometry and background amplitude reduction and compensationUS6124931Jan 16, 1999Sep 26, 2000Zygo CorporationApparatus and methods for measuring intrinsic optical properties of a gasUS6271923Aug 27, 1999Aug 7, 2001Zygo CorporationInterferometry system having a dynamic beam steering assembly for measuring angle and distanceUS6330065Apr 28, 1999Dec 11, 2001Zygo CorporationGas insensitive interferometric apparatus and methodsUS6445453Aug 2, 2000Sep 3, 2002Zetetic InstituteScanning interferometric near-field confocal microscopyUS6447122Dec 20, 1999Sep 10, 2002Minolta Co., Ltd.Projection image display device using a reflective type display elementUS6480285Mar 16, 2000Nov 12, 2002Zetetic InstituteMultiple layer confocal interference microscopy using wavenumber domain reflectometry and background amplitude reduction and compensationUS6552805Jul 27, 2001Apr 22, 2003Zetetic InstituteControl of position and orientation of sub-wavelength aperture array in near-field microscopyUS6552852Dec 20, 2001Apr 22, 2003Zetetic InstituteCatoptric and catadioptric imaging systemsUS6597721Sep 21, 2000Jul 22, 2003Ut-Battelle, LlcMicro-laserUS6606159Aug 2, 2000Aug 12, 2003Zetetic InstituteOptical storage system based on scanning interferometric near-field confocal microscopyUS6667809Jul 27, 2001Dec 23, 2003Zetetic InstituteScanning interferometric near-field confocal microscopy with background amplitude reduction and compensationUS6714349Mar 25, 2002Mar 30, 2004Samsung Sdi Co., Ltd.Screen and projection display system with improved viewing angle characteristicUS6717736Feb 13, 2003Apr 6, 2004Zetetic InstituteCatoptric and catadioptric imaging systemsUS6753968Jan 30, 2003Jun 22, 2004Zetetic InstituteOptical storage system based on scanning interferometric near-field confocal microscopyUS6775009Jul 27, 2001Aug 10, 2004Zetetic InstituteDifferential interferometric scanning near-field confocal microscopyUS6847029Jul 27, 2001Jan 25, 2005Zetetic InstituteMultiple-source arrays with optical transmission enhanced by resonant cavitiesUS6847452Jul 29, 2002Jan 25, 2005Zygo CorporationPassive zero shear interferometersUS20020074493Jul 27, 2001Jun 20, 2002Hill Henry A.Multiple-source arrays for confocal and near-field microscopyUS20020131179Dec 20, 2001Sep 19, 2002Hill Henry A.Catoptric and catadioptric imaging systemsUS20030174992Sep 27, 2002Sep 18, 2003Levene Michael J.Zero-mode metal clad waveguides for performing spectroscopy with confined effective observation volumesUS20040201852Feb 4, 2004Oct 14, 2004Zetetic InstituteCompensation for effects of mismatch in indices of refraction at a substrate-medium interface in non-confocal, confocal, and interferometric confocal microscopyUS20040201853Feb 13, 2004Oct 14, 2004Zetetic InstituteTransverse differential interferometric confocal microscopyUS20040201854Feb 19, 2004Oct 14, 2004Zetetic InstituteLongitudinal differential interferometric confocal microscopyUS20040201855Feb 19, 2004Oct 14, 2004Zetetic InstituteMethod and apparatus for dark field interferometric confocal microscopyUS20040202426Feb 6, 2004Oct 14, 2004Zetetic InstituteMultiple-source arrays fed by guided-wave structures and resonant guided-wave structure cavitiesUS20040227950Apr 1, 2004Nov 18, 2004Zetetic InstituteApparatus and method for measurement of fields of backscattered and forward scattered/reflected beams by an object in interferometryUS20040227951Apr 1, 2004Nov 18, 2004Zetetic InstituteApparatus and method for joint measurement of fields of scattered/reflected or transmitted orthogonally polarized beams by an object in interferometryUS20040228008Apr 1, 2004Nov 18, 2004Zetetic InstituteMethod for constructing a catadioptric lens systemUS20040246486Jan 27, 2004Dec 9, 2004Zetetic InstituteInterferometric confocal microscopy incorporating a pinhole array beam-splitterUS20040257577Jan 27, 2004Dec 23, 2004Zetetic InstituteApparatus and method for joint measurements of conjugated quadratures of fields of reflected/scattered and transmitted beams by an object in interferometryUS20050036149Jul 7, 2004Feb 17, 2005Zetetic InstituteApparatus and method for high speed scan for detection and measurement of properties of sub-wavelength defects and artifacts in semiconductor and mask metrology* Cited by examinerNon-Patent CitationsReference1U.S. Appl. No. 09/852,369, filed Jan. 03, 2002, Hill.2U.S. Appl. No. 09/917,402, filed Jul. 27, 2001, Hill.3U.S. Appl. No. 10/765,254, filed Jan. 27, 2004, Hill.4U.S. Appl. No. 10/765,368, filed Jan. 27, 2004, Hill.5U.S. Appl. No. 10/886,157, filed Jul. 07, 2004, Hill.6U.S. Appl. No. 60/442,858, filed Jul. 27, 2002, Hill.7U.S. Appl. No. 60/442,982, filed Jan. 29, 2003, Hill.8U.S. Appl. No. 60/443,980, filed Jan. 31, 2003, Hill.9U.S. Appl. No. 60/444,707, filed Jan. 4, 2003, Hill.10U.S. Appl. No. 60/445,739, filed Feb. 7, 2003, Hill.11U.S. Appl. No. 60/447,254, filed Feb. 13, 2003, Hill.12U.S. Appl. No. 60/448,250, filed Jan. 19, 2003, Hill.13U.S. Appl. No. 60/448,360, filed Feb. 19, 2003, Hill.14U.S. Appl. No. 60/459,425, filed Apr. 11, 2003, Hill.15U.S. Appl. No. 60/459,493, filed Apr. 1, 2003, Hill.16U.S. Appl. No. 60/460,129, filed Apr. 3, 2003, Hill.17U.S. Appl. No. 60/485,255, filed Jul. 7, 2003, Hill.18U.S. Appl. No. 60/485,507, filed Jul. 7, 2003, Hill.19U.S. Appl. No. 60/501,666, filed Sep. 10, 2003, Hill.20U.S. Appl. No. 60/506,715, filed Sep. 26, 2003, Hill.Referenced byCiting PatentFiling datePublication dateApplicantTitleUS7428058May 15, 2006Sep 23, 2008Zetetic InstituteApparatus and method for in situ and ex situ measurements of optical system flareUS7508527Apr 10, 2006Mar 24, 2009Zetetic InstituteApparatus and method of in situ and ex situ measurement of spatial impulse response of an optical system using phase-shifting point-diffraction interferometryClassifications U.S. Classification356/496International ClassificationG02B, G01B9/02, G02B21/00Cooperative ClassificationG01B9/02003, G01B9/02024, G01B2290/70, G01B9/02022, G02B21/00European ClassificationG01B9/02, G02B21/00Legal EventsDateCodeEventDescriptionFeb 14, 2012FPExpired due to failure to pay maintenance feeEffective date: 20111225Dec 25, 2011LAPSLapse for failure to pay maintenance feesAug 1, 2011REMIMaintenance fee reminder mailedMay 16, 2005ASAssignmentOwner name: ZETETIC INSTITUTE, ARIZONAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HILL, HENRY A.;REEL/FRAME:016219/0026Effective date: 20050506RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google