Abstract: A structured light sensor system for measuring contour of a surface includes a control module that coordinates control of both a projection system and an imaging system to operate the structured light sensor system in three different modes. The imaging system is configured to selectively capture an image of light reflected off of the surface. In point mode, the imaging system is on for a first period during which the projection system projects a point of light onto the surface. In line mode, the imaging system is on for a second period during which the projection system projects onto the surface a first plurality of points of light forming a line of light. In area mode, the imaging system is on for a third period during which the projection system projects onto the surface a second plurality of points of light forming a plurality of lines of light.

Abstract: The rough bottom surface of a recessed feature partially obscured by an overlying structure is profiled interferometrically with acceptable precision using an objective with sufficiently large numerical aperture to illuminate the bottom under the obscuring structure. The light scattering produced by the roughness of the surface causes diffused light to return to the objective and yield reliable data fringes. Under such appropriate numerical-aperture and surface roughness conditions, the bottom surface of such recessed features can be profiled correctly simply by segmenting the correlograms produced by the scan and processing all fringes that correspond to the bottom surface elevation.

Abstract: A reference image to serve as a reference for a non-defective determination is previously stored in association with identification information for identifying an inspection object. An image of the inspection object is displayed side by side with the reference image of corresponding identification information. A drawn position of the reference image and a drawn position of the acquired image are aligned, adjustment is made so as to make brightness of the reference image coincide with brightness of the acquired image, and adjustment is made so as to make a focus on the reference image coincide with a focus on the acquired image. Adjustment is made so as to make a focus of the reference image coincide with a focus of the acquired image.

Abstract: Systems and methods are presented to enhance and isolate residual signals indicative of the speckle field based on measurements taken by optically based metrology systems. Structural irregularities such as roughness and topographical errors give rise to light scattered outside of the specularly reflected component of the diffracted light. The scattered light interferes constructively or destructively with the specular component in a high numerical aperture illumination and detection system to form a speckle field. Various methods of determining residual signals indicative of the speckle field are presented. Furthermore, various methods of determining structural irregularities based on analysis of the residual signals are presented. In various embodiments, illumination with a high degree of spatial coherence is provided over any of a wide range of angles of incidence, multiple polarization channels, and multiple wavelength channels.

Abstract: Methods of performing surface profilometry are provided. A low coherence light beam is scanned relative to a sample surface. The intensity of interference fringes generated by the interference of a sample beam and a reference beam are recorded by an image sensor. Variations of light intensity around each pixel are calculated in terms of variance or standard derivation. The peak position of variance on a particular location along vertical scan direction is identified as the scan position corresponding to zero optical path difference between the reference and measuring beams. A topography map (height map) may be generated using the relative scanning position where zero optical path difference occurs at each location on sample surface.

Abstract: In-situ calibration of an interferometer includes making a sequence of phase measurements of a test object using the interferometer, each of the measurements having a same carrier fringe frequency, where at least some of the measurements are made at three or more different orientations of carrier fringes, and determining information about the test object based on at least some of the phase measurements, in which determining the information includes reducing errors in the measurements arising from imperfections in the interferometer based on the measurements made at the three or more different orientations.

Abstract: A method of measuring surface curvature comprises forming an intensity distribution defined by Fresnel diffraction, wherein said intensity distribution is formed by electromagnetic radiation reflected from a surface, obtaining data for the intensity distribution and determining information relating to the curvature of the surface using the obtained data.

Abstract: The invention relates to the field of measurement technology and concerns a method and an apparatus, such as may be used, by way of example, in thin-layer technology for organic dielectric semi-conducting or conducting layers on substrates. The object of the invention is to indicate a method and an apparatus with which both the surface topography of the coating and that of the surface may be determined independently of one another, at the same position. The object is achieved by a method wherein the three-dimensional topography of the coating is determined using chromatic white light measurement and, subsequently, the thickness of the coating is determined using UV interferometry, and the surface topography of the coated surface is determined by a comparison with the overall dimensions of the coated surface. The object is further achieved by an apparatus wherein an apparatus for chromatic white light measurement and an apparatus for UV interferometry are disposed on a test bench.

Abstract: A surface profile measuring apparatus includes a reflection unit to reflect a reference beam diffracted by a first diffraction grating and cause the reflected reference beam to be incident on the first diffraction grating again, a detection unit to receive an interference beam in which the reference beam diffracted again by the first diffraction grating and a measuring beam reflected by a sample surface optically interfere with each other, and detect an interference intensity signal for each, wavelength in the interference beans, a shifting unit to shift the first diffraction grating in a direction perpendicular to a grating groove direction of the first diffraction grating, a calculation unit to calculates a phase on a basis of the interference intensity signal for each wavelength varying with a degree of shift, and a measurement unit to measure the sample surface.

Abstract: An object of the present invention is to provide an optical inspection apparatus that suppresses an influence of quantum noise and obtains superior defect detection performance even when an amount of light is small and a method thereof. In order to resolve the above problem, the present invention provides an optical inspection apparatus that includes a light source which radiates light to a sample; a light interference device which causes target light transmitted, scattered, or reflected from the sample and reference light to interfere with each other, such that strength of light after the interference becomes lower than strength of the target light; a photon counter which measures a photon number of the light after the interference by the light interference device; and a defect identifier which identifies the presence or absence of a defect, on the basis of a detected photon number obtained by the photon counter.

Abstract: A measuring device that measures a measurement object includes a two-dimensional measuring unit that outputs two-dimensional image data by performing image pickup on the measurement object, a three-dimensional measuring unit that outputs three-dimensional data by three-dimensionally measuring the measurement object; and an obtaining unit that detects a temporary edge of the measurement object using the three-dimensional data, sets an edge detection range in a two-dimensional image using the detected temporary edge, and detects an edge of the measurement object in the edge detection range using the two-dimensional image data to obtain shape information of the measurement object.

Abstract: A shape measuring apparatus (1) measures a workpiece shape utilizing white light interference, and includes a stage (10) on which a workpiece (W) is placed, an interference optical system (100) that irradiates the workpiece (W) with white light (WL) to generate a white light interference moire, a drive unit (26) that moves one of the stage and the interference optical system in a direction of an optical axis, a length measuring device (50) that measures a relative distance (L) between the stage and the interference optical system changed by the drive unit, and an imaging unit (40) that images the white light interference moire to acquire contrast information of the white light interference moire that changes according to the relative distance.

Abstract: An apparatus for detecting a 3D structure of an object. The apparatus has first and second laser emitters which generate laser radiation having first and second wavelengths, respectively, the first wavelength being different from the second wavelength. Optical devices are disclosed, including a beam splitter, which splits the laser radiation of the laser emitters in each case into a reference radiation and an illuminating radiation. The illuminating radiation impinges upon the object to be measured, is reflected by the object as object radiation and interferes with the reference radiation. A detector receives the interference patterns. The laser emitters are located such that the illuminating radiation of the first and second laser emitters impinge upon the object at different angles of incidence. Also discussed is a measuring device which measures the two wavelengths of the laser radiation of the laser emitters and influences the recording of the interference patterns.

Abstract: Provided herein is a TSV measuring interferometer that uses a variable field stop that adjusts such that a light is focused at an inlet and at a bottom surface of a TSV when measuring a diameter and depth of the TSV, thereby reducing a measurement time and result data, the interferometer also using a telecentric lens that adjusts the light injected into the TSV to be a straight line, so as to obtain a sufficient amount of light reaching the bottom surface to improve the accuracy of measurement even in a TSV having a large aspect ratio.

Abstract: Interferometer systems and methods for measurement of shapes as well as their derivatives and thickness variations of wafers are disclosed. More specifically, shearing interferometry techniques are utilized in such measurement systems. The output of the measurement systems can be utilized to determine at least one of: a surface slope, a surface curvature, a surface height, a shape, and a thickness variation of the wafers.

Abstract: Apparatus and methods for detecting optical profile are disclosed herein. In one embodiment, an apparatus includes a laser, a beam splitter, a collimation optical unit, first and second holders respectively holding a first test flat mirror and a second test flat mirror, a phase shifter connected with the first holder, and an angular measurement unit for measuring an angular error of the first test flat mirror and the second test flat mirror on the two holders. The first test flat mirror has a first test flat and the second test flat mirror has a second test flat. The apparatus further includes a planar imaging unit for generating the interfered test light having a direction generally along an x-axis direction of the first test flat and an x-axis direction of the second test flat and a convergence optical unit for projecting the interfered test light onto a detector.

Abstract: An apparatus measures a shape of an object by detecting interfering light between reference light and test light. The apparatus includes a detector configured to detect the interfering light, an optical member located between the object and the detector and including a light attenuating part, and an adjusting unit configured to adjust a relative position and/or angle between the optical member and an optical path of the test light. A part of the test light from a second region, having surface roughness smaller than that of a first region in the region including the measured region of the object is attenuated by the light attenuating part. The detector detects interfering light between the reference light and test light from the first region and the second region after passing through the optical member.

Abstract: A method of providing high accuracy inspection or metrology in a bright-field differential interference contrast (BF-DIC) system is described. This method can include creating first and second beams from a first light beam. The first and second beams have round cross-sections, and form first partially overlapping scanning spots radially displaced on a substrate. Third and fourth beams are created from the first light beam or a second light beam. The third and fourth beams have elliptical cross-sections, and form second partially overlapping scanning spots tangentially displaced on the substrate. At least one portion of the substrate can be scanned using the first and second partially overlapping scanning spots as the substrate is rotated. Radial and tangential slopes can be determined using measurements obtained from the scanning using the first and second partially overlapping scanning spots. These slopes can be used to determine wafer shape or any localized topography feature.

Abstract: Provided is an optical surface profilometer. The optical surface profilometer includes a Fabry-Perot resonator into which liquid crystals are inserted, a light source which supplies coherent light to the Fabry-Perot resonator, and a convex lens which is disposed in an interference pattern emitting plane of the Fabry-Perot resonator, wherein the coherent light supplied from the light source is incident to the Fabry-Perot resonator, wherein, when the light is incident, the Fabry-Perot resonator emits an interference pattern generated in a resonance mode, and wherein the interference pattern is configured so that a number of circular fringes having the same center are disposed non-linearly. As a voltage is applied to the liquid crystal layer of the Fabry-Perot resonator, an effective refractive index is changed, so that a resonance mode condition of the Fabry-Perot resonator is changed. As a result, a diameter of the interference pattern is also changed.

Abstract: The properties of a surface of an object in presence of thin transparent films are determined by generating a library of model signals and processing a measurement signal via searching the library to evaluate films properties and topography. The library may be reduced with principal component analysis to enhance computation speed. Computation enhancement may also be achieved by removal of the height contributions from the signal leaving only the film contribution in the signal. The film measurement signal is compared to a library of film signals to determine the film parameters of the sample. The library of film signals is produced by processing each full signal in a library to similarly remove the height contributions leaving only the film contributions. Additionally, a post-analysis process may be applied to properly evaluate local topography.

Abstract: An apparatus and a method capable of measuring large deformation with a high accuracy and dynamically, using speckle interference, utilizes an optical path where one laser beam out of two laser beams becomes non-collimated light and a plane parallel transparent plate, and can form carrier fringes. More specifically, the transparent plate is arranged on the optical path where the non-collimated light is formed, or is removed from the optical path, or a refractive index, or a thickness of the transparent plate arranged on the optical path, or a tilt angle relative to an optical axis is changed. The phase analysis can be performed from fringe images corresponding to the deformation, by performing repetitively the above-described processing and acquisition of the speckle interference pattern.

Abstract: A interferometer apparatus for studying the surface of an object, the apparatus comprising a source producing an object beam of coherent light, a source producing a reference beam which is coherent with the object beam, and a detector or a plurality of detectors arranged in a line or array, wherein the apparatus is arranged such that the object beam is diverging or substantially collimated, and wherein, in use the diverging or substantially collimated object beam is directed towards the surface of the object to produce a reflected object beam reflected from the surface of the object, the detector(s) is/are focused to a point beneath the surface of the object, and the reflected object beam is combined with the reference beam and detected by the detector(s). Also provided is a corresponding method for conducting an interferometric study of the surface of an object.

Abstract: The instant disclosure describes an optical device for the interferometric analysis of the surface condition of an object, including: a light source; an optical fiber capable of receiving the incident light wave and transmitting said wave to the object; a detector capable of detecting a combination between a light wave reflected by the optical fiber and a light wave returned by the object; and in which the optical fiber has a free end in the shape of a cone, with a vertex angle of between 15 and 25 degrees, the tip of the cone having dimensions of less than 50×50 nm, and the tip of the cone being placed, while in use, at a distance of between 5 and 50 ?m from the surface of the object.

Abstract: A system for generating an image of contoured surface includes a light source that is configured to project an electromagnetic radiation beam onto the contoured surface, wherein the projected beam generates first radiation reflected from a first portion of the contoured surface to form a speckle pattern, and second radiation reflected from a second portion of the contoured surface which is substantially uniform in intensity. The reflected first and second reflected radiation is received by an optical detector, and may be processed. The processing is configured to (1) generate a plurality of images from the first and second reflected radiation, with each image being generated using different coherence length electromagnetic radiation from the light source, and (2) generate a 3-D image of the contoured surface from the plurality of images. Methods for generating a 3-D image of a contoured surface are also disclosed.

Abstract: Methods of performing surface profilometry are provided. A low coherence light beam is scanned relative to a sample surface. The intensity of interference fringes generated by the interference of a sample beam and a reference beam are recorded by an image sensor. Variations of light intensity around each pixel are calculated in terms of variance or standard derivation. The peak position of variance on a particular location along vertical scan direction is identified as the scan position corresponding to zero optical path difference between the reference and measuring beams. A topography map (height map) may be generated using the relative scanning position where zero optical path difference occurs at each location on sample surface.

Abstract: An interference measuring apparatus measuring a distance to a surface for inspection is provided. The interference measuring apparatus includes a light dividing unit that divides each of the plurality of light fluxes into light to be inspected and reference light; an objective lens that transmits light to be inspected; a photoelectric conversion element that receives interference light between the light to be inspected and the reference light for each of the plurality of light fluxes and output an interference signal obtained by converting the interference light into an electrical signal; and a calculation unit that calculates the distance to the surface to be inspected based on a phase obtained by subtracting a defocused wavefront from a phase component of a complex amplitude at the pupil position of the objective lens which transmitted light to be inspected for each of the plurality of light fluxes by using the interference signal.

Abstract: A method for absolute measurement of flatness of surfaces of optical elements. In the method, an interferometer having a measurement axis is used for applying a three-flat method by three optical elements, by conducting actual measurements on the elements, and planes of the elements are reconstructed by an iterative processing operation in which measurements are simulated and simulated measurements are compared with the actual measurements. At least two actual measurements are made after having performed a rotation around the measurement axis and/or a translation perpendicularly to the measured axis, of a measured optical element relatively to the other.

Abstract: A shape of a surface is measured using a measurement signal based on an interfering light of reference light of first light reflected by a reference surface and test light of second light reflected by the surface to be measured. The method includes detecting the measurement signal and a reference signal based on interfering light of the first light not incident on the reference surface and the second light not incident on the surface to be measured, obtaining a sine multiplied signal and a cosine multiplied signal of the measurement signal, correcting the sine multiplied signal and the cosine multiplied signal by a sine signal and a cosine signal of the error component; obtaining a phase by calculating an arctangent of the corrected sine multiplied signal and the corrected cosine multiplied signal and obtaining the shape based on the phase.

Abstract: A non-energy dissipating, curvature sensing device senses curvature variation of a sample and comprises an outer layer, an inner layer and at least one spacer. The outer layer is flexible, transparent material and has a shape. The inner layer is flexible, transparent material, has a shape corresponding to the shape of the outer layer, is positioned under the outer layer and is thicker and harder than the outer layer. At least one spacer is positioned between the outer layer and the inner layer and creates space between the outer layer and the inner layer. A non-energy dissipating, curvature sensing method is also disclosed.

Abstract: Provided is a scanning optical measurement apparatus having super resolution.

Abstract: The present invention relates to a verification method for tracking and tracing tablets, particularly pharmaceutical tablets. It further relates to a visible secure marking or information that is a part of such tablet (10). The invention further relates to tablets suitable for such verification method, processes for manufacturing such tablets, and methods for reading the information.

Abstract: Systems and methods are provided which derive target characteristics from interferometry images taken at multiple phase differences between target beams and reference beams yielding the interferometry images. The illumination of the target and the reference has a coherence length of less than 30 microns to enable scanning the phase through the coherence length of the illumination. The interferometry images are taken at the pupil plane and/or in the field plane to combine angular and spectroscopic scatterometry data that characterize and correct target topography and enhance the performance of metrology systems.

Abstract: A system of computing surface reconstruction, in-plane and out-of-plane displacements and strain distribution utilizes the optical switching element to switch the reference beam to analyze the images of the test object before and after deformation, to measure the topography, in-plane and out-of-plane displacements and surface two-dimensional strain distribution on the test surface of the test object, and thus to increase the measurement range on the test surface of the test object with the use of image registration. Thereby, the complexity and error of scanning the test object can be reduced. Such a system need not to move the image capturing device or test object to generate relative displacement for reaching the measurement effect of the test surface of the test object in three-dimensional coordinates.

Abstract: Methods and apparatus for method for characterizing a height profile of a scattering surface relative to a fiducial plane. The scattering surface, which may be an interface between distinct solid, liquid, gaseous or plasma phases, is illuminated with substantially spatially coherent light, and light scattered by the scattering surface is collected and dispersed, such as by a grating, into zeroth- and first-order beams. A spatial Fourier transform of the zeroth- and first-order beams is created, and one of the beams is low-pass filtered. The beams are interfered at a focal plane detector to generate an interferogram, which is transformed to retrieve a spatially resolved quantitative phase image and/or an amplitude image of the scattering surface. Imaging may be performed during an etching process, and may be used to adaptively control a photoetching process in a feedback loop.

Abstract: A shape measuring method includes guiding light emitted from a light source to an object to be measured and a reference surface, combining light reflected from the object to be measured with light reflected from the reference surface, and taking a distribution image of an interference light intensity corresponding to each measurement position of the object to be measured, while changing an optical path length difference between a first optical path length and a second optical path length over a whole scanning zone, sequentially storing distribution images of the interference light intensity in the whole scanning zone, and obtaining an interference light intensity string at each measurement position based on the stored distribution images of the interference light intensity, and obtaining a position in an optical axis direction at each measurement position of the object to be measured from a peak position of the interference light intensity string.

Abstract: Measuring a shape of an optical surface (14) of a test object (12) includes: providing an interferometric measuring device (16) generating a measurement wave (18); arranging the measuring device (16) and the test object (12) consecutively at different measurement positions relative to each other, such that different regions (20) of the optical surface (14) are illuminated by the measurement wave (18); measuring positional coordinates of the measuring device (16) at the different measurement positions in relation to the test object (12); obtaining surface region measurements by interferometrically measuring the wavefront of the measurement wave (18) after interaction with the respective region (20) of the optical surface (14) using the measuring device (16) in each of the measurement positions; and determining the actual shape of the optical surface (14) by computationally combining the sub-surface measurements based on the measured positional coordinates of the measuring device (16) at each of the measurement

Abstract: Provided is a measurement method or apparatus that can reduce the time for measuring the shape of an entire test surface. Each of a plurality of measurement ranges is set so that one measurement range overlaps a portion of at least another measurement range to form an overlap region, each measurement range being a portion of the test surface. Then, the shape of the test surface is measured at a first resolution in a first measurement range among the plurality of measurement ranges, and is measured at a second resolution in a second measurement range. Pieces of data of the shapes of the test surface in the plurality of measurement ranges are stitched together using the resulting measurement data to calculate the shape of the test surface.

Abstract: A system for imaging a textured surface includes a light source that is configured to project an electromagnetic radiation beam onto the textured surface, wherein the projected beam generates first radiation reflected from a first portion of the textured surface to form a speckle pattern, and second radiation reflected from a second portion of the textured surface which is substantially uniform in intensity. The reflected first and second reflected radiation is received by an optical detector, and may be processed to generate an image of the textured surface from the first and second reflected radiation. Methods for textured surface sensing are also disclosed.

Abstract: Provided herein is a TSV measuring interferometer that uses a variable field stop that adjusts such that a light is focused at an inlet and at a bottom surface of a TSV when measuring a diameter and depth of the TSV, thereby reducing a measurement time and result data, the interferometer also using a telecentric lens that adjusts the light injected into the TSV to be a straight line, so as to obtain a sufficient amount of light reaching the bottom surface to improve the accuracy of measurement even in a TSV having a large aspect ratio.

Abstract: A patterned sapphire substrate is measured from a fine phase map and a coarser height map of the sample. The boundaries of the PSS features are identified by finding the locations of minimum contrast in the modulation map of the substrate and are used to produce a height map of the substrate base and a phase map of center regions of the features. A fringe-order map of the features with respect to the base is used to identify the most prevalent fringe order of pixels in the center-regions of the features. That fringe order is adopted as the correct offset between corresponding pixels in the phase map of the center regions of the features and the base of the substrate. A complete map of the substrate is thus obtained by combining the phase map of the features with the height map of the substrate with an offset equal to the fringe order produced by the invention.

Abstract: A surface to be inspected is step-scanned in multiple steps. In each step, the phase corresponding to a shape measurement region in an interference fringe pattern, and the wavelength of light are measured. After defining a distance between any point on the surface to be inspected and the center of curvature of a reference spherical surface as a function of wavenumber (integer) including the measured phase and wavelength as parameters, the wavenumber in each step is calculated from the relationship of the function between adjacent steps, and the moving distance between each step is calculated. A measurement value of the distance is calculated from the wavenumber and the function thereof, a design value of the distance is calculated using the calculated moving distance, and the shape error of the surface to be inspected is calculated from the difference between the measurement value and the design value.

Abstract: An imaging apparatus includes a light source; a first beam splitter for reflecting a projection beam emitted by the light source; an objective lens unit including a reflection reference surface for reproducing the projection beam into a measurement beam projected onto an object to generate a first reflection beam and a reference beam projected onto the reflection reference surface to generate a second reflection beam mixing with the first reflection beam and passing through the first splitter and forming an operating beam; a second beam splitter for modulating the operating beam into first and second sub-beams; a monochrome image detection device for passage of the first sub-beam to obtain an interferometric image with monochrome from a first interference region; and an image detection device for permitting passage of the second sub-beam in order to obtain a non-interferometric image from a second interference region.

Abstract: The shape measurement device 1 comprises a light source 11, a measuring beam illumination system 13, a reference comb light separator 14, an optical multiplexer 15 and photodetector 16. The reference comb light separator 14 enters with a broadband light, and it separates in a reference comb light with broadband light. The frequency interval of the reference comb light changes continually depending on a size of Y-coordinate level in the image formation point, when the emission direction is assumed Z-axis direction. X-axis means a virtual cutout line for the measuring object, and Y-coordinate means depth for measuring. The interference image emerging in the detective surface is a tomogram for the measurement substantially. Using the reference comb light, the two-dimensional dislocation of depth direction is measured, wherein the dynamic range is extremely wide.

Abstract: A white light optical profilometer having a measurement head that is separated from the base unit by means of a fiber optic bundle. The measurement head contains a Michelson objective, whose reference path is folded so that the measurement head may be compact. The measurement head also contains a tilting mirror, which directs light from the surface of interest to the objective, and may be adjusted to allow the measurement head to scan complex surfaces. The base unit contains the other elements of the profilometer, such as an image detector and illuminator.

Abstract: An integrated optical shape sensing system and method include an arrangement structure (132) configured to receive a fiber port or connector. A platform (130) is configured to provide a distance relationship with the arrangement structure such that the fiber port or connector is trackable to provide a location reference. The platform secures a patient in proximity to the arrangement structure. An optical shape sensing enabled interventional instrument (102) has a first optical fiber cable connectable to the fiber port or connector. An optical interrogation module (108) is configured to collect optical feedback from the instrument and has a second optical fiber cable connectable to the fiber port or connector such that a known reference position is provided for accurate shape reconstruction.

Abstract: The liquid droplet discharging apparatus includes an image formation area and two inspection areas. The apparatus includes a pair of workpiece stages each configured to support a workpiece thereon, an inspection stage arranged between the two workpiece stages, a pair of image recognizing sections configured to execute image recognition with respect to an inspection discharge result discharged onto the inspection stage, and a stage moving mechanism configured to selectively move one of workpiece stages between the image formation area and one of the workpiece exchange areas, to selectively move the other of the workpiece stages between the image formation area and the other of the workpiece exchanges areas, and to move the inspection stage between the inspection areas.

Abstract: An interferometric method for detecting information about a sample includes emitting a laser beam; splitting the laser beam into a reference beam and an object beam; transmitting the object beam through the sample in an incident angle; combining the reference beam with the object beam passed through the sample to form an interference pattern; detecting the interference pattern, and non-linearly scanning the object beam in order to detect a plurality of interference patterns.

Abstract: A surface profile measuring apparatus includes a reflection unit to reflect a reference beam diffracted by a first diffraction grating and cause the reflected reference beam to be incident on the first diffraction grating again, a detection unit to receive an interference beam in which the reference beam diffracted again by the first diffraction grating and a measuring beam reflected by a sample surface optically interfere with each other, and detect an interference intensity signal for each, wavelength in the interference beans, a shifting unit to shift the first diffraction grating in a direction perpendicular to a grating groove direction of the first diffraction grating, a calculation unit to calculates a phase on a basis of the interference intensity signal for each wavelength varying with a degree of shift, and a measurement unit to measure the sample surface.

Abstract: Disclosed is an interference objective lens unit, comprising: an objective lens; a beam splitter that splits the light transmitted through the objective lens into a reference optical path in which a reference mirror is provided and a measuring optical path in which the measuring object is placed, and that superposes the split lights to output interference light; a first holder that holds the objective lens and that is formed by material having a first linear expansion coefficient; and a second holder that holds the reference mirror and that is formed by material having a second linear expansion coefficient different from the first linear expansion coefficient, wherein when a usage environment temperature changes, a difference in the linear expansion coefficients between the first holder and the second holder corrects an optical path difference between the reference optical path and the measuring optical path.

Abstract: The invention relates to a method and an apparatus for determining the height of a number of spatial positions on the sample, defining a height map of a surface through interferometry with a broadband light source. The method can involve for each spatial position: obtaining a correlogram during scanning of the surface plane of the objective and estimating the point of the correlogram where an amplitude of the correlogram is at its maximum, thus determining an approximation of the height of the spatial position on the sample. The estimation of the value where the correlogram has its maximum can involve subjecting the correlogram to a Fourier transform, subjecting the Fourier transformed signal to a filter, subjecting the filtered signal to an inverse Fourier transform, and calculating the location of the center of mass of the inversed filtered Fourier transformed signal.