Abstract: Flatness and thickness variation information concerning transmissive plane-parallel test plates is obtained from a grazing incidence interferometer modified to distinguish between superimposed interference patterns containing both types of information. The grazing angle of the interferometer is varied, and unique modulation frequencies of local fringe intensities within the superimposed interference patterns are identified. The local fringe intensities attributable to the different interference patterns are distinguished by their respective modulation frequencies.

Abstract: A method of measuring the rate of etching of trenches on a substrate using interferometry is provided. The method comprises transmitting onto the substrate incident electromagnetic radiation having a wavelength above the wavelength at which the trenches act as waveguides for the radiation; collecting reflected electromagnetic radiation from the substrate; detecting a repetitive pattern of maximum intensities and minimum intensities of the reflected electromagnetic radiation during the etching; and determining the rate of etching based upon the wavelength of the incident electromagnetic radiation and the time period of the pattern.

Abstract: Integrated measurement apparatus and method for measuring layer thickness and bow in a wafer. The apparatus comprises: a monochromatic light source, a white light source, a first switch for switching between the white light source and the monochromatic light source, a plurality of optical heads for directing light from the switched light source onto different locations on a semiconductor wafer surface, a first optical processor for spectral processing of reflected light from the wafer, a second optical processor for processing of reflected light to determine an extent of bow in the wafer, and a second optical switch to switch reflected light from the wafer between the first optical processor and the second optical processor so that the white light is spectrally processed to determine layer thicknesses and the monochromatic light is processed for bowing.

Abstract: A spin etcher with a thickness measuring system includes a rotatable spin head, etchant supply means, and etchant supply controller. A substrate is mounted upon the spin head. The etchant supply means is disposed over the substrate, and sprays an etchant onto the substrate. The etchant supply controller controls the etchant supply. The spin etcher further includes a main controller for transferring an etchant supply stop signal to the thickness measuring system and the etchant supply controller. The thickness measuring system allows a light to impinge on a surface of the substrate, and analyzes an interference signal of the light reflected from the substrate to measure a thickness of a thin film. The main controller compares a result measured by the thickness measuring system with a reference value, and transfers the etchant supply stop signal to the etchant supply controller before the measured result reaches the reference value.

Abstract: A monochromatic light is cast on a thin layer, and the intensity of the reflected light which is an interference light of the lights reflected by the front surface and back surface of the layer. A spectrum (a measured spectrum) is obtained from the measured intensity by scanning the wavenumber of the monochromatic light. On the other hand, a constructed spectrum is created based on an assumed thickness using a predetermined function. Then an error between the measured spectrum and the constructed spectrum is calculated. The value of the error is plotted against the assumed thickness, and the point at which the error is minimum is detected. The assumed thickness at the error-minimum point is determined as the thickness of the layer.

Abstract: To provide a film thickness testing apparatus and a film thickness testing method in which coherence between light reflected from the surface of a film and light reflected from the surface of a substrate is improved so as to accurately visually test film thickness irregularities. Film thickness testing is conducted by using a light source part for irradiating a substrate with light having an intensity peak with a half band width of 30 nm or less and having spectral intensity in a peak wavelength region alone.

Abstract: The disclosed method of measuring the thickness of an active layer of an SOI substrate maintains the accuracy of previous methods but can be performed quickly and during processing of the substrate. The method includes reading data from light reflected from the substrate. A range of light wavelengths for analysis is selected, which avoids the problem of nodes, at which interference between light reflected from different surfaces is weakened. The method determines a relationship between wavelength and reflection intensity and determines peak values of the relationship. The wavelengths corresponding to an arbitrary pair of the peak values, and the number of waves between the peak values, are used to calculate the thickness of the active layer. The method includes an error correction procedure that increases measurement accuracy.

Abstract: Process and apparatus for automated production of optical devices comprising two plane parallel optical surfaces of a desired optical performance for transmitted light, by measuring and quantifying the spectral response of intensity versus wavelength across the working surface area of a starter optical device as compared to an acceptable computer model, as a three dimensional contour map of optical thickness based on the assumption of a constant index of refraction, then reducing the high spots by automated means such as polishing, and measuring the spectral response again.

Abstract: A method and device for measuring cell gap of a liquid crystal display, the display comprising a pair of substrates with electrodes adhered together forming a predetermined sized cell gap. The device and method includes radiating near-infrared light toward the liquid crystal cell, reflectively interfering the near-infrared light by the cell gap, and analyzing the interference waveform to compute the cell gap size. The device may include an X-Y stage, an FT-NIR spectroscope using near-infrared light as light source, a detector unit for detecting reflected interference light from the liquid crystal cell, and an analyzing computer unit for analyzing and computing cell gap by performing Fourier transformation method or maximum entropy method (MEM) to the interference fringe spectrum.

Abstract: The invention concerns a method for the determination of layer thicknesses and optical parameters of a number of layers of a specimen, in which the reflectance spectrum of the specimen is measured and then smoothed, and a modeled reflectance spectrum is adapted to the measured one by means of an optimization criterion so as thereby to determine the layer thickness.

Abstract: The invention relates to an apparatus for devices for determining properties of thin layers applied on a substrate. This apparatus comprises two changing magazines wherein one magazine is provided for crystal resonators and the other magazine for test glasses. The changing magazine for crystal resonators has the form of a disk and is encompassed by the annular magazine for test glasses. Both can be rotated independently of one another. Each position of the magazines can be reproduced with the aid of sensors and evaluation devices. Consequently, it is possible to carry out multiple coatings.

Abstract: A method of measuring the rate of etching of trenches on a substrate using interferometry is provided. The method comprises transmitting onto the substrate incident electromagnetic radiation having a wavelength above the wavelength at which the trenches act as waveguides for the radiation; collecting reflected electromagnetic radiation from the substrate; detecting a repetitive pattern of maximum intensities and minimum intensities of the reflected electromagnetic radiation during the etching; and determining the rate of etching based upon the wavelength of the incident electromagnetic radiation and the time period of the pattern.

Abstract: A method to determine the systematic error of an instrument that measures features of a semiconductor wafer includes the following sequential steps. Collecting sensor data from measurement runs on front and back surfaces of a wafer while the wafer is oriented at different angles to the instrument for each run, yielding a front data set and a back data set for each angle. Then organizing the data in each set into a wafer-fixed coordinate frame. Reflecting all back surface data about a diameter of the wafer creates a reflected back data set. Subtracting the reflected back data from the front data for each wafer angle, and dividing the result by two, yields an averaged wafer shape for each load angle. Adding the reflected back data to the front data and dividing the result by two, yields an instrument signature for each load angle. The symmetric corrector is calculated by taking the average over all instrument signatures at each load angle.

Abstract: The present invention provides a method for monitoring a modifying-process taking place in a thin-film sample and thereby characterizing the sample thus modified, wherein the modifying-process is performed for purpose of improving physical properties of the sample. The present invention further provides a monitoring tool for characterizing various thin-film processes. Advantages of the method of the present invention are manifest in its non-intrusive nature, fast (or real-time) response, robust sensitivity, and versatility in a variety of thin-film processes. Another inherent advantage of the present invention is that an assortment of the “n&k” parameters can be obtained by using only measurement tool, in contrast to two (or more) simultaneous measurement tools used in the prior art.

Abstract: A monitoring apparatus for a polishing pad. A chemical mechanical polishing machine, a polishing pad, a measuring device, and a display device are provided. The polishing pad is situated in a predetermined position in the chemical mechanical polishing machine. The measuring device is coupled to the chemical mechanical polishing machine to measure the thickness of the polishing pad. The measured thickness of the polishing pad is displayed on the display device.

Abstract: An inventive method for optically detecting a trench depth in a wafer is disclosed. The method includes detecting a first maxima in the intensity of a multi-wavelength light source, a portion of the light being reflected from the top trench surface of a wafer. A second maxima is then detected in the intensity of the multi-wavelength light source, a portion of which being reflected from the bottom trench surface of a wafer. The method further includes determining a maxima peak difference between the first maxima and the second maxima, wherein the trench depth corresponds to the maxima peak separation. The invention provides a robust, cost effective method for trench depth detection.

Abstract: A sensing system and method for biomolecular sensing. The system includes: a receptor for the at least one target, the receptor including a substrate and a transparent coating on the substrate having front and back surfaces; a light source positioned to direct at least a portion of light from the light source toward the coating on the receptor; and a detector positioned to capture the light reflected from the front and back surfaces of the coating, the detector identifying presence of at least one target based on a change in the interference pattern of captured light.

Abstract: Disclosed is a thin-film inspection device with two or more light sources. This device can control the wavelength and intensity of light and illuminate the lights with different incident angles, and are used to control the interference intensity, thereby determining optimal inspection conditions to obtain a reliable inspection result even when different kinds of thin films coexist. The thin films are formed on a flat plate and have different indices of refraction and thicknesses. An incident light control unit is disposed between the illumination unit and the flat plate for controlling the light to be incident on the patterns. A sensor unit detects a reflection light from the patterns. A reflection light control unit is disposed between the flat plate and the sensor unit and controls the light to be detected by the sensor unit. A control unit controls the movement of the illumination unit and the sensor unit.

Abstract: A method and system using spectral interference of light from plasma emissions collected at near grazing incidence to in-situ monitor and control the film thickness of a non-opaque film. Embodiments of this invention are particularly useful to all substrate processing chambers equipped to form an in-situ plasma within the chamber and which are used to deposit or etch non-opaque films. One embodiment of the method of the present invention forms a plasma within a substrate processing chamber to deposit a non-opaque film on a wafer substrate within the chamber. During the plasma deposition process, a plurality of wavelengths of radiation including those reflected from the top and bottom layer of the film being deposited upon a wafer surface are collected through an existing viewport, and conveyed to a spectrometer for measurements via an optical fiber attached near this viewport. These measurements are analyzed to determine the film's thickness.

Abstract: Standard patterns of differential values of interference light that correspond to a predetermined step height of the first material being processed and standard patterns of differential values of interference light that correspond to a predetermined remaining mask layer thickness of the material are set. These standard patterns use wavelengths as parameters. Then, the intensities of interference light of multiple wavelengths are measured for a second material that has the same structure as the first material. Actual patterns with wavelength as parameter are determined from differential values of the measured interference light intensities. Based on the standard patterns and the actual patterns of the differential values, the step height and the remaining mask layer thickness of the second material are determined.

Abstract: In a phase unwrapping method for fringe image analysis, when storing newly calculated numeric data into a storage list, the new numeric data is initially compared with numeric data of a representative rank within each rank block in the storage list, whereby the rank block to store the data is chosen. Subsequently, the new numeric data is compared with each of respective numeric data within thus chosen rank block, so as to determine a rank at which the new numeric data is to be stored, and then is stored into the storage list. Along with the storing of numeric data, rank data is updated.

Abstract: In order to be able to automatically define significant measurement points for measuring the film thickness of a transparent film on a circuit pattern buried under an optically transparent thin film, in a method for determining measurement points for measuring film thickness, whereby measurement points for measuring the film thickness of optically transparent thin film on a circuit pattern formed on a wafer beneath an optically transparent thin film, are determined automatically, light is irradiated onto the surface of the wafer, either intermittently or continuously, starting at a predetermined provisional reference measurement point in the region of a particular chip on the wafer, and following a predetermined path of travel in the vicinity of this provisional reference measurement point, the light reflected by the wafer is detected, and the measurement points for measuring film thickness are determined on the basis of spectral waveform data for the reflected light thus detected.

Abstract: The surface form of a semiconductor thin film such as a polysilicon film 13 formed on a semiconductor substrate 11 is measured through spectro-ellipsometry or measured by performing an IPA quantitative analysis through GC. Mass (gas chromatography) after exposing the semiconductor thin film to IPA (isopropyl alcohol) vapor and drying the semiconductor thin film. Through either of these methods the surface form of the polysilicon film easily and quickly measured.

Abstract: A method for producing an interferogram of an infrared translucent layer that is on a reflective substrate, comprising generating parallel infrared interferometer beams by means of an infrared interferometer, converging the parallel infrared interferometer beams into converging infrared interferometer beams, sending the converging infrared interferometer beams onto the infrared translucent layer to produce diffusely reflected infrared interferometer rays from above and below the infrared translucent layer, and making the diffusely reflected infrared interferometer rays into parallel reflected infrared interferometer rays.

Abstract: The invention relates to a method for measuring characteristics, especially the temperature of a multi-layer material during the build-up of the layers, especially of a stratified semiconductor system during epitaxy under constant process conditions.

Abstract: A method and an apparatus for optically determining a physical parameter such as thickness t, index of refraction n, extinction coefficient k or a related physical parameter such as energy bandgap Eg of a thin film. A test beam having a wavelength range &Dgr;&lgr; is used to illuminate the thin film after it is deposited on a complex substrate which has at least two layers and exhibits a non-monotonic and an appreciably variable substrate optical response over wavelength range &Dgr;&lgr;. Alternatively, the thin film can be deposited between the at least two layers of the complex substrate. A measurement of a total optical response, consisting of the substrate optical response and an optical response difference due to the thin film is performed over wavelength range &Dgr;&lgr;. The at least two layers making up the complex substrate are chosen such that the effect of multiple internal reflections in the complex substrate and the film is maximized.

Abstract: A high-resolution and high-speed film thickness and thickness uniformity measurement method is disclosed in this invention. The disclosed method includes a step a) of measuring a film thickness at a single point on the top surface of the substrate using an interferometry with a measuring light beam having a range of wavelengths. The method further includes a step b) of selecting an optimal wavelength from the range of wavelengths applied for measuring the film thickness at the single point. The method further includes a step c) of measuring reflection intensities by scanning over a plurality of points with a measuring light beam of the optimal wavelength over the top surface of the substrate. The method further includes a step d) of calculating a film thickness at the plurality of points applying the optimal-wavelength reflection intensities at the plurality of points over the top surface of the substrate.

Abstract: A method and apparatus are provided for measuring a depth geometry of a structure on a semiconductor substrate including a plurality of recessed and non-recessed portions, wherein one of the recessed and non-recessed portions includes a reference interface and one of the recessed and non-recessed portions has a dielectric layer thereon. A broadband light source irradiates the substrate and a detector detects a first spectral component comprising light reflected from the non-recessed portions, a second spectral component comprising light reflected from the recessed portions, and a third spectral component comprising light reflected from the dielectric layer. Spectral reflectance information of the detected rays is stored and a plot of reflectance intensity versus wavelength is generated. A depth geometry of one of the recessed portions and the dielectric layer are determined relative to the reference interface, based on an interferometric analysis of the plot.

Abstract: A method is described for determining more accurate Cauchy coefficients for a constant-angle reflection-interference spectrometer (CARIS). This allows photoresist thicknesses for product wafers to be measured more accurately. The method for determining the Cauchy coefficients consists of coating monitor wafers with photoresist layers having various thicknesses formed by varying the spin speed during photoresist coating. The photoresist layers are then patterned using monochromatic radiation through a mask and developing photoresist. The monochromatic radiation has a dose sufficient to just clear the photoresist layers from the surface of the wafers during development. The linewidths of the photoresist are measured and plotted as a function of photoresist thickness to generate a critical dimension (CD) swing curve having an essentially sinusoidal shape that results from interference between the transmitted and reflected monochromatic radiation in the photoresist.

Abstract: A method for optically measuring layer thickness in accordance with the present invention includes the steps of providing a first metal layer on a semiconductor device structure, providing a second metal layer on the first metal layer, forming a dielectric layer over the second metal layer and directing light onto the structure such that light reflected from a surface of the dielectric layer and a surface of the second metal layer create an interference pattern from which the dielectric layer thickness is measured. A system for optically measuring layer thickness includes a semiconductor device to be measured. The semiconductor device includes a first metal layer, a second metal layer disposed on the first metal layer, the second metal layer having an arcuate shaped top surface and a dielectric layer disposed on the second metal layer.

Abstract: An optical system is fabricated in the form of one device, so that the simplified optical system is realized. A displacement is measured with a high resolving power utilizing an interference fringe. An interference measurement probe 2 receives a coherent light from a light source section 1, and divides the coherent light into a plurality of luminous fluxes. The interference measurement probe 2 emits a plurality of irradiation luminous fluxes at different angles. The plurality of irradiation luminous fluxes form an interference fringe and the interference fringe is irradiated onto an objective 8. A light receiving section 3 is disposed at a position where a reflection luminous flux from the objective 8 interferes, and receives an interference light reflected from the objective 8, thereby outputting a light receiving signal which is converted to an electric signal.

Abstract: The CCD device is suitable for use in a lidar. It has an image zone constituted by a matrix of M lines and N columns of photosensitive sites for receiving a light signal and generating charges, a first memory zone constituted by a matrix of P lines and N columns of non-photosensitive sites, a read-out register having a single line of N sites, and a second memory zone having P lines of N sites, apt to receive in parallel charges contained in the N sites of the read-out register. The first memory zone has a first line of sites apt to receive and to sum charges generated in a respective column of the image zone at the end of each of successive acquisition periods. The second memory zone stores and transfers charges to N sites of a same line of the image zone or the first memory zone whereby accumulating, in each line of the first memory zone, charges accumulated during an observation period and resulting from a plurality of successive summations.

Abstract: An integrated night vision device and laser range finder (10) provides night-time imaging of a scene by use of an image intensifier tube (14), as well as providing laser range finding operations. In a laser range finder mode of operation the device (10) projects a pulse of laser light into a scene being viewed, and a power supply and laser range finder circuit (50) of the device (10) temporarily utilizes the image intensifier tube (14) as a sensor to detect reflected laser light. During laser range finding, imaging is cut off for a very short time interval, and the image intensifier tube provides an electrical output signal in response to receipt of reflected laser light. A detection circuit (86, 86') associated with the image intensifier tube (10) receives the electrical output signal from the image intensifier tube (14), and includes a magnetic circuit. Oscillation in the magnetic circuit is effected by the electrical output signal of the image intensifier tube (14).

Abstract: Apparatus for creating an image indicating distances to objects in a scene, comprising: a modulated source of radiation, having a first modulation function, which directs radiation toward a scene; a detector, which detects radiation reflected from the scene, modulated by a second modulation function, and generates, responsive to said detected modulated radiation, signals responsive to the distance to regions of the scene; a processor, which receives signals from the detector and forms an image, based on the signals, having an intensity value distribution indicative of the distance of objects from the apparatus; and a controller, which varies at least one of the first and second modulation functions, responsive to the intensity value distribution of the image formed by the processor.

Abstract: A multichannel laser radar has a laser array transmitter for generating a multiple laser beam array and a multichannel laser beam receiver for receiving reflected multiple laser beam array signals transmitted by said laser array transmitter. The multichannel laser beam receiver has a plurality of optical fibers coupled to a plurality of multichannel optical receiver photonic hybrid circuit boards for receiving reflected signals and processing the received signal range information and forming an image therefrom. Each circuit board has at least one detector assembly mounted thereon and each detector assembly has a plurality of photodetectors mounted to receive one end of each optical fiber so that a multichannel laser radar generates and receives multiple laser beams and parallel processes the received multiple laser beams to generate an image therefrom.

Abstract: A laser transmitter is amplitude modulated with a chirp signal to illumin an entire scene or field of view. A mixing process occurs in the received light path using an electro-optic light modulator positioned just in front of the focal plane detector array. The detector array detects and integrates the mixed light signal over some field of view. Numerous image frames are recorded periodically in the time over the FM period. The Fourier transform taken over time for a pixel establishes the range to the target in that pixel. Performing the Fourier transform for all pixels yields a three-dimensional image of objects in the field of view. Such an arrangement yields a scannerless ladar possessing high range resolution with no range ambiguities.

Abstract: A method and apparatus for generating a range image and an intensity image of a target field is disclosed. The range image and the intensity image are fused into a single image that contains range and intensity information. In one embodiment, only a single range band is illuminated with colors in the fused image. This range band can be scrolled throughout the fused image to detect three dimensional features more clearly.

Abstract: A laser ranging system which includes a laser pulse emitter, an imaging and impingement detecting amplifier and a system processor is provided. The laser pulse emitter produces a pulse of light to be reflected by at least one object at an unknown distance from the laser emitter. The detecting sensor has a multiplicity of photoelements and collects reflected light from the object. The detecting sensor determines the intensity of the reflected light and the time it first impinged on each of the photoelements. The system processor controls the laser pulse emitter and the detecting sensor. The system processor also receives output from the detecting sensor to produce at least distance indications for the object based on the length of time from emission of the pulse of light to receipt of its reflection as sensed by each of the photoelements.

Abstract: A range imaging device such as a distance camera is improved by incorporating an oscillator to generate a reference signal, a light source to emit a light modulated in accordance with the reference signal and to project the light onto a three-dimensional target. A condenser lens collects and condenses a secondary light reflected by the target and projects the secondary light onto a gating image intensifier, which selectively gates the secondary light in synchronism with a pair of out-of-phase gate signals generated in accordance with the reference signal. Range information contained in the secondary light is extracted by the gating process. A CCD camera receives the gated secondary light and produces a corresponding image signal which is processed to produce a range image of the target.

Abstract: A method and apparatus for imaging objects in turbid mediums, such as water, the invention using a laser pulse, a detector of the reflected laser pulse, and a shutter on the detector. The shutter is kept closed except at the expected return time of the laser pulse from the reflected object to be detected and identified at which time the shutter is opened to permit the detector to receive the reflected laser pulse. Typically, laser pulses with widths of about 100 to about 500 psecs are used. In addition, typical shutter times or gate widths of about 100 to about 500 psecs are also used. Gate widths on the order of 120 psecs are preferred. The detector or GOI camera is shielded from spurious signals, most notably, scattered laser light from the turbid medium.