Abstract: An interferometery system for making interferometric measurements of an object, the system including: a beam generation module which during operation delivers an output beam that includes a first beam at a first frequency and a second beam at a second frequency that is different from the first frequency, the first and second beams within the output beam being coextensive, the beam generation module including a beam conditioner which during operation introduces a sequence of different shifts in a selected parameter of each of the first and second beams, the selected parameter selected from a group consisting of phase and frequency; a detector assembly having a detector element; and an interferometer constructed to receive the output beam at least a part of which represents a first measurement beam at the first frequency and a second measurement beam at the second frequency, the interferometer further constructed to image both the first and second measurement beams onto a selected spot on the object to produce

Abstract: An imaging system for imaging an object point to an image point, the system including: a beam splitter positioned to receive light rays from the object point and separate each of a plurality of rays into a transmitted portion and a reflected portion, the transmitted portions defining a first set of rays and the reflected portions defining a second set of rays; and an array of independently positionable reflecting elements forming a reflecting surface positioned to receive one of the sets of rays from the beam splitter and focus that set of rays towards the image point via the beam splitter.

Abstract: Methods and apparatus are disclosed for measurement of critical dimensions (CD) of features and detection of defects in reflecting UV, VUV, and EUV lithography masks and in transmitting UV and VUV lithography masks. The measured CD's may be used in the determination of optical proximity corrections (OPC) and/or in mask fabrication process control. The transmitting masks may comprise binary and various types of phase shift masks.

Abstract: A method of processing a substrate on which a layer of photoresist has been applied, the method involving: exposing the layer of photoresist to radiation that carries spatial information to generate exposure-induced changes in the layer of photoresist that form a pattern having one or more features; and before developing the exposed photoresist, interferometrically obtaining measurements of the pattern in the exposed layer of photoresist for determining at least one of (1) locations of the one or more features of the pattern and (2) magnitudes of the exposure-induced changes.

Abstract: A method of detecting non-uniform ellipsometric properties of a substrate surface involving: directing a measurement beam onto a spot at a selected location on or in the substrate; for each orientation of a plurality of different orientations of the reference beam relative to the scattered measurement beam, interfering the scattered measurement beam with the reference beam to produce a corresponding interference beam, wherein each of the different orientations of the reference beam is selected to produce a peak sensitivity for a portion of the scattered measurement beam that emanates from the object at a corresponding different diffraction angle of a plurality of diffraction angles; for each orientation of the reference beam, converting the interference beam into an interference signal; and using the interference signals to determine whether any non-uniform ellipsometric properties are present anywhere within a region on or in the substrate.

Abstract: 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.

Abstract: Methods and apparatus based on optical homodyne displacement interferometry, optical coherent-domain reflectometry (OCDR), and optical interferometric imaging are disclosed for overlay, alignment mark, and critical dimension (CD) metrologies that are applicable to microlithography applications and integrated circuit (IC) and mask fabrication and to the detection and location of defects in/on unpatterned and patterned wafers and masks. The metrologies may also be used in advanced process control (APC), in determination of wafer induced shifts (WIS), and in the determination of optical proximity corrections (OPC).

Abstract: Beam shearing apparatus for introducing a lateral shear between the components of a light beam. The apparatus is an optical assembly having a polarizing interface and input and output facets and two reflecting surfaces one of which is arranged at an angle generally opposite the input facet and the other of which is arranged at an angle generally opposite the output facet.

Abstract: A multiple source array including a guided-wave structure having a dielectric core and a cladding covering the dielectric core; and an array of dielectric-filled, guided-wave cavities in the cladding extending transversely from the dielectric core and forming an array of apertures through which optical energy that is introduced into the core exits from the core.

Abstract: An interferometric microscope for making interferometric measurements of locations within an object that is in a medium, there being a mismatch between indices of refraction of said object and said medium, the microscope including a source for generating an input beam; an interferometer which is configured to receive the input beam and generate therefrom a measurement beam, to focus the measurement beam onto a selected spot in the object and produce for that selected spot a return measurement beam, and to combine the return measurement beam and a reference beam to produce an interference beam; and a detector system which is positioned to receive the interference beam, wherein the return measurement beam travels along a path from the object to the detector system and wherein the interferometer includes a compensating layer of material positioned in the path of the return measurement beam, the compensating layer producing a mismatch in the index of refraction along the path of the return measurement beam that c

Abstract: A method of interferometrically obtaining measurements for properties associated with a spot on or in an object, the method involving: receiving a sequence of M optical pulses separated in time; from each pulse in the sequence of M optical pulses, generating an n-tuplet of measurement pulses, and an n-tuplet of reference pulses, wherein each measurement pulse has a corresponding reference pulse aligned with it in time; from each pulse of each n-tuplet of reference pulses for the sequence of M optical pulses, generating a reference beam; from each pulse of each n-tuplet of measurement pulses for the sequence of M optical pulses, (a) generating a measurement beam; (b) directing the measurement beam onto the spot to thereby produce a return measurement beam from the spot; and (c) combining the return measurement beam with the corresponding reference beam that was derived from the reference pulse corresponding to that measurement pulse to generate an interference beam, wherein the sequence of M n-tuplets of measu

Abstract: An interferometry system including: a first imaging system that directs a measurement beam at an object to produce a return measurement beam from the object, that directs the return measurement beam onto an image plane, and that delivers a reference beam to the image plane; and a beam combining element in the image plane, said beam combining element comprising a first layer containing an array of sagittal slits and a second layer containing an array of tangential slits, wherein each slit of the array of sagittal slits is aligned with a corresponding different slit of the array of tangential slits, wherein the beam combining element combines the return measurement beam with the reference beam to produce an array of interference beams.

Abstract: A differential interferometric confocal microscope for measuring an object, the microscope including a source-side pinhole array; a detector-side pinhole array; and an interferometer that images the array of pinholes of the source-side pinhole array onto a first array of spots located in front of an object plane located near where the object is positioned and onto a second array of spots behind the object plane, wherein the first and second arrays of spots are displaced from each other in both a direction normal to the object plane and a direction parallel to the object plane, the interferometer also imaging the first arrays of spots onto a first image plane that is behind the detector-side pinhole array and imaging the second array of spots onto a second image plane that is in front of the detector-side pinhole array wherein each spot of the imaged first array of spots is aligned with a corresponding different spot of the imaged second array of spots and a corresponding different pinhole of the detector-side

Abstract: A method of making interferometric measurements of an object, the method including: generating an input beam that includes a plurality of component beams, each of which is at a different frequency and all of which are spatially coextensive with each other, some of the components beams having a first polarization and the rest having a second polarization that is orthogonal to the first polarization; deriving a plurality of measurement beams from the plurality of component beams, each of the plurality of measurement beams being at the frequency of the component beam from which it is derived; focusing the plurality of measurement beams onto a selected spot to produce a plurality of return measurement beams; combining each of the return measurement beams of the plurality of return measurement beams with a different corresponding reference beam of a plurality of reference beams to produce a plurality of interference beams; and acquiring a plurality of electrical interference signal values for the selected spot fro

Abstract: A confocal interferometry system for making interferometric measurements of an object, the system including an array of pinholes positioned to receive a source beam and, for each pinhole in the array of pinholes, separate the source beam into a corresponding reference beam on one side of the array of pinholes and a corresponding measurement beam on the other side of the array of pinholes; a first imaging system arranged to image the array of pinholes onto an array of spots on or in the object so that the corresponding measurement beam for each pinhole of the array of pinholes is directed to a different corresponding spot of the array of spots and produces for that spot a corresponding return measurement beam, the first imaging system also arranged to image the array of spots onto the array of pinholes so that the corresponding return measurement beam from each spot of the array of spots is directed back to a corresponding different pinhole in the array of pinholes, wherein for each pinhole the pinhole array c

Abstract: A method of detecting defects or artifacts on or in an object, wherein the defects or artifacts are characterized by a characteristic dimension, the method involving: generating an input beam for illuminating a spot at a selected location on or in the object, wherein the spot has a size L that is substantially larger than the characteristic dimension; deriving a measurement beam and a reference beam from the input beam; directing the measurement beam onto the object as an incident measurement beam that illuminates the spot at that selected location on or in the object to produce a backscattered measurement beam; interfering the backscattered measurement beam with the reference beam to produce an interference beam, the reference beam being oriented relative to the backscattered measurement beam so as to produce a peak sensitivity for a portion of the backscattered measurement beam that emanates from the object at a predetermined diffraction angle; converting the interference beam for that selected location int

Abstract: An interferometry system including an interferometer that includes a source imaging system that focuses an input beam onto a spot on or in the object and an object imaging system that images the spot onto a detector element as an interference beam, wherein the source imaging system is characterized by a first aperture stop that defines a first aperture and includes a first phase shifter that introduces a first phase shift in light passing through a first region of the first aperture relative to light passing through a second region of the first aperture, and wherein the object imaging system is characterized by a second aperture stop that defines a second aperture and includes a second phase shifter that introduces a second phase shift in light passing through a first region of the second aperture relative to light passing through a second region of the second aperture.

Abstract: A method of fabricating a catadioptric lens system, the method involving: fabricating a single catadioptric lens element having a bottom surface and an upper surface, the upper surface having a convex portion and a concave portion, both the convex and concave portions sharing a common axis of symmetry; cutting apart the catadioptric lens element to form 2n pie-shaped segments, wherein n is an integer; and reassembling the 2n pie-shaped segments to form the catadioptric lens system with n of the 2n pie-shaped segments being located above a common plane and the rest of the 2n pie-shaped elements being below the common plane.

Abstract: An array of conjugated quadratures of fields is measured interferometrically by a confocal interferometer and detector system wherein each conjugated quadratures comprises a difference of conjugated quadratures of fields of beams scattered/reflected or transmitted by a pair of spots in or on a substrate. The array of conjugated quadratures is measured jointly, i.e., simultaneously, and the components of each conjugated quadratures may be measured jointly. Each pair of spots generally has a relative displacement on the order of the three or more times the size of the spots in a direction nominally tangent to the surface of the substrate. The relative phases of the beams subsequently scattered/reflected or transmitted by the pair of spots on/in a substrate may be adjusted as a set by control of a single system parameter so that the conjugated quadratures of the array of conjugated quadratures are nominally zero, i.e.

Abstract: A differential interferometric confocal microscope for measuring an object, the microscope including: a source-side pinhole array; a detector-side pinhole array; and an interferometer that images the array of pinholes of the source-side pinhole array onto a first array of spots located in front of an object plane located near where the object is positioned and onto a second array of spots behind the object plane, wherein the first and second arrays of spots are displaced relative to each other in a direction that is normal to the object plane, the interferometer also (1) imaging the first arrays of spots onto a first image plane that is behind the detector-side pinhole array, (2) imaging the first array of spots onto a plane defined by the detector-side pinhole array, (3) imaging the second array of spots onto a second image plane that is in front of the detector-side pinhole array, and (4) imaging the second array of spots onto the plane defined by the detector-side pinhole array, wherein each spot of the im