Abstract: Light is transmitted through a compressing clamp which clamps the liquid crystal display panel 10, and the spectrum of light is obtained by a spectrometer 141. A cell thickness is detected based on a wavelength or a frequency at which the spectrum has the minimum or maximum value. The obtained cell thickness is compared with a desired value, and a pressure control unit 132 supplies the compressing clamp with a fluid in accordance with the result of the comparison.

Abstract: An apparatus for processing substrates according to a predetermined photolithography process is presented. The apparatus includes a loading station in which the substrates are loaded, a coating station in which the substrates are coated with a photoresist material, an exposing station in which the photoresist coating is exposed to light through a mask having a predetermined pattern to produce a latent image of the mask on the photoresist coating, a developing station in which the latent image is developed, an unloading station in which the substrates are unloaded and a monitoring station for monitoring the substrates with respect to predetermined parameters of said photolithography process before reaching the unloading station. The monitoring station comprises an optical monitoring system comprising a spectrophotometric channel, and is accommodated in a sealed enclosure, such that incident light passes through the optical system towards the substrate through a transparent window.

Abstract: A system for evaluating a donor cornea includes a light source for generating a beam having a predetermined characteristic and a selected configuration. The light beam characteristic can be collimated light (wavefront analysis), white light (spectral analysis), or polarized light (polarization analysis). The beam configuration can be either circular in cross-section, or it can be a slit. When circular, the light beam is transmitted through the entire cornea to identify changes in the characteristics of the light (e.g. phase shift, spectral shift, or polarization changes). These changes then determine the optical properties of the donor cornea. When configured as a slit, the light is scattered off-axis and used to measure dimensions for a profile of the donor cornea. A computer then prepares an evaluation which includes information on both the optical qualities and the dimensional profile of the donor specimen.

Abstract: A method of measuring film thickness is based on the film's attenuation of optical characteristics, such as absorption band or absorption bands, of underlying material. The thickness of the film is determined based on a correlation between the thickness of the film and the strength of the absorption band (such as a peak or valley area) of the underlying material. The correlation is generated using an identified absorption band of the underlying material, which may be determined empirically or using a library of information, and the reflectance spectra produced by calibration samples, each having a different thickness of film.

Abstract: A method and system for measuring threshold length of a planarization process, and for comparing the planarization abilities of such processes. The method and system measure a thickness profile of a film on a blanket wafer, and from the thickness profile, a threshold length is calculated.

Abstract: Process for continuous determination of the optical layer thickness of coatings, which are applied on both sides of the spherical surfaces of concave convex lenses having different spherical radii R1 and R2. In this process a ray of light is beamed eccentrically during the coating process at each concave convex lens, and the reflection or transmission at the convex spherical surface and at the concave spherical surface is continuously measured with photodiodes, and the respective optical layer thickness is determined from the functional relationship between the reflection or the transmission and the optical layer thickness.

Abstract: A method of determining a physical characteristic of a hollow transparent article includes positioning the article at an inspection station, creating a scanning light beam which is split into two inspection light beams which are caused to impinge on different portions of the article. A plurality of sensors receive light reflected from the external and internal surfaces of the wall of the article and convert the same into corresponding electrical signals. The electrical signals are based upon the elapsed time from the initiation of the light beam or scanning light beam until arrival of a reflected light beam at least two sensors. The transparent article may, for example, be a container or tube. The inspection light beams are preferably caused to impinge on the article from opposed directions with each impinging on the article within about 70° degrees and preferably about 60° degrees of a radial plane perpendicular to the article.

Abstract: A method and an apparatus for measuring thickness of transparent films is described in which an illumination beam is directed through an objective onto an object comprising a transparent film. A structured focusing aid is disposed in the illumination beam, a camera is disposed in an imaging beam. The focusing aid and the camera each are disposed in locations conjugated with the focal plane of the objective. The focal plane of the objective is displaced stepwise through the object. At each position, a camera image is recorded and its focus score is determined, the image of the focusing aid being used as the contrast indicator. The positions with maximal focus scores are assigned to the locations of the interfaces. The thickness of the transparent film is calculated from the difference between the positions of its interfaces.

Abstract: A method of measuring the thickness of a cell gap of a reflective type liquid crystal display. An optical system having a rotating table, an input polarizer, a beam splitter, and a output polarizer is used. A reflective type liquid crystal device is disposed on a rotating table. An incident light is reflected by the liquid crystal device. The reflective type liquid crystal device is located between the input polarizer and the output polarizer. A beta angle &bgr; is defined as the angle between the input light polarization and the front liquid crystal director. A first formula is used to express the relationship between the reflectivity R⊥ and &bgr;. The reflectivity is R⊥ then differentiated by &bgr; to obtain a second formula that express the relationship between &bgr;max and the thickness of the cell gap. The rotating table is rotated to measure the maximum value &bgr;max of the angle &bgr;. The thickness d can thus be obtained more precisely.

Abstract: A method and apparatus for performing reflectometry using a specific wavelength or a small number of specific wavelengths within a spectral range to detect the presence of a copper oxide film on a substrate or to measure the film thickness is described. A method for analyzing reflectivity data to obtain film thickness is also described. Using the described method and apparatus, reflectometry can be performed using only one or two wavelengths of light so that simple photodiode detectors may be used instead of a complex and costly spectrometer (although a spectrometer may be used to detect the reflected light). Therefore, the described invention can provide in-situ or vacuum integrated metrology with simple, low-cost hardware. Finally, the described method does not require detailed curve fitting and thus the necessary thickness data can be acquired rapidly.

Abstract: A beam deflection technique for simultaneous measurements of the thickness, refractive index and optical absorption of transparent materials using a charge coupled device (CCD) camera is provided. The method comprises measuring beam deflection after transmission through or reflection off a sample of interest at variable incidence angles to the sample surface. The measurement of beam deflection as a function of incident angle is related through Snell's Law directly to the sample thickness and sample index of refraction.

Abstract: Disclosed are methods and apparatus for reducing thermal loading of a film disposed on a surface of a sample, such as a semiconductor wafer, while obtaining a measurement of a thickness of the film in an area about a measurement site. The method includes steps of (a) bringing an optical assembly of the measurement system into focus; (b) aligning a beam spot with the measurement site; (c) turning on one of a dither EOM or a dither AOM or a piezo-electric dither assembly to sweep the beam spot in an area about the measurement site, thereby reducing the thermal loading within the measurement site; (d) making a measurement by obtaining a signal representing an average for the film under the area; (e) recording the measurement data; and (f) analyzing the measurement data to determine an average film thickness in the measurement area.

Abstract: The disclosure describes an exemplary method of detecting a process end point during etching in the fabrication of an integrated circuit. This method can include receiving a reference signal indicative of an intensity of a light source, collecting a reflection signal reflected off a surface of an integrated circuit wafer, and comparing the reference signal and the reflection signal to locate absorption bands, the absorption band being indicative of a process end point.

Abstract: A method for the production of multi-layer systems with N layers having predetermined thickness, especially for the production of multi-layer systems for wavelength ranges in the extreme ultraviolet and soft X-ray wavelength range is described, in which N layers are deposited and if need be one or more layers are partially removed after deposited and in wich at the same time as deposition and/or removal of layers, the layers' reflectivity dependent on layer thickness is measured. The method includes the following steps: Calculation of a reflectivity-time curve of the multi-layer system to be produced Determination of points in time ti (i=1, 2, . . . , N), at which the deposition of the i-th layer is to be stopped; and if need be determination of points in time ti′ (i=1, 2, . . .

Abstract: A method for measuring at least one desired parameter of a patterned structure having a plurality of features defined by a certain process of its manufacturing. The structure represents a grid having at least one cycle formed of at least two locally adjacent elements having different optical properties in respect of incident radiation. An optical model is provided, which is based on at least some of the features of the structure defined by a certain process of its manufacturing, and on the relation between a range of the wavelengths of incident radiation to be used for measurements and a pitch of the structure under measurements. The model is capable of determining theoretical data representative of photometric intensities of light components of different wavelengths specularly reflected from the structure and of calculating said at least one desired parameter of the structure.

Abstract: A method is described for analyzing and characterizing parameters of a semiconductor wafer. In particular, an approach is described for characterizing the interface layer between a thin oxide film and a silicon substrate in order to more accurately determine the characteristics of the sample. The wafer is inspected and a set of measured data is created. This measured data is compared with theoretical data generated based on a theoretical set of parameters as applied to a model representing the physical structure of the semiconductor. The model includes an interface layer, between the film layer and the silicon substrate, which includes a representation of the electronic structure of the underlying substrate. In the preferred embodiment, the representation is a five peak, critical point model influenced by the electronic transitions of the underlying silicon substrate.

Abstract: A method for polishing wafers includes providing a wafer having a grating structure and a process layer formed over the grating structure; illuminating at least a portion of the process layer and the grating structure with a light source; measuring light reflected from the illuminated portion of the process layer and the grating structure to generate a reflection profile; and determining planarity of the process layer based on the reflection profile. A metrology tool adapted to receive a wafer having a grating structure and a process layer formed over the grating structure includes a light source, a detector, and a data processing unit. The light source is adapted to illuminate at least a portion of the process layer overlying the grating structure. The detector is adapted to measure light reflected from the illuminated portion of the process layer and the grating structure to generate a reflection profile.

Abstract: A system for measuring the thickness of a wafer while it is being thinned this disclosed. The system and method provide integrating an optical reflectometer into a common wafer thinning apparatus. Using reflected optical signals from the top and bottom of the wafer, the thickness of the wafer is determined with time based calculations in real-time while thinning is occurring. Once the desired thickness has been reached, the thinning operation is halted. By performing the measurement in-situ, this system and a method prevent scrapping of wafers which are overthinned and the reloading of wafers which are too thick. Since an optical reflectometer is used, the measurement is contactless, and thus prevents possible damage to wafers during measurement.

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 method for determining a wafer characteristic, such as the surface quality of a film formed on the wafer, using a film thickness monitor is described. In one embodiment, the method comprises the following steps. A measured spectrum for a processed wafer is generated. A set of parameters is chosen and then used to generate a calculated spectrum. The measured spectrum is compared to the calculated spectrum to determine if the two spectra match. If the two spectra do not match or the degree of nonconformity between the two spectra is greater than an acceptable error value, then there is probably a defect with the processed wafer. For example, the film formed on the wafer may have a nonuniform or hazy surface quality.

Abstract: An optical filter having a precise optical thickness is produced by controlling the optical thickness of the film formed on the product substrate precisely. The optical thickness of the film formed on the monitoring chip 2 and the data of the relation of this optical thickness to the reflectance of the film are determined beforehand and used as film thickness control data. On arranging both the product substrate 3 and the monitoring chip 2 within the film forming area 7 to form films on these substrates simultaneously, the correction coefficient for correcting the amount of deviation of the optical thickness of the film formed on the product substrate 3 from the optical thickness of the film formed on the monitoring chip 2 is provided by the film thickness correction coefficient data determined beforehand, for example for each film material and according to the monitor light wavelength.

Abstract: A property of a layer of a phosphor screen on a substrate is determined by sending a beam of infrared radiation through the substrate and the layer and measuring, after the passage, the intensity of the beam. The radiation can be measured by a CCD camera.

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.