Abstract: A fast method simulates photolithography using conventional image processing techniques. Convolution simulates blurring due to optics; erosion and dilation correct for edge diffraction. To produce the convolution kernel, an effective projection lens image for the image source is produced by convolving the lens image with an image of the illuminator aperture shape. An effective projection lens image for the stepper is produced similarly. The stepper effective lens image is divided by the image source effective lens image to produce a corrected effective lens image. A corrected convolution kernel is produced by taking a Fourier transform of the corrected effective lens image. The kernel is used to convolve the image, once using energy and once using voltage, and then squaring the result. The aerial image is produced by blending the energy and voltage convolutions according to the computed partial coherence of the optics. Complex convolution is used to represent relative phases other than 180 degrees.

Abstract: A fast method simulates photolithography using conventional image processing techniques. Convolution simulates for blurring; erosion and dilation correct for edge diffraction. In one technique, the source image of the photomask is deconvolved to sharpen it and then dilated to remove edge diffraction. The image is eroded, and then convolved according to the resolution of the stepper at the photomask plane. This aerial image can be further eroded to match the effects of resist and developing. Optional thresholding is done to produce a simulated processed wafer image. In a fast technique, the deconvolution step is eliminated. Dilation and erosion are combined into a single erosion. Where a phase shift mask is involved, a complex convolution is used. Source data can come from the photomask electronic design or from a visual image of the actual photomask. Optimizations include: special microprocessor instructions, floating point pixel values, separable convolution and annular illumination simulation.

Abstract: An OPC feature measurement technique accurately measures serif area of OPC features, feature separation and line symmetry, and is especially useful for measuring dimensions which are less than about the wavelength of the examining radiation. The relative area of serifs present on a line end is measured by first defining a region of interest around the line end and then an intensity profile is created. The differences between data points on the profile and a constant value are summed in order to calculate a flux value. The flux value is divided by the intensity range to determine an area. The separation distance between a line end and another feature is determined by first defining a region of interest that spans the separation distance between the two features. Next, an intensity profile is created. The differences between data points on the profile and a constant value are summed to calculate a flux value. The separation distance between the features is calculated from the flux value.

Abstract: An x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array. The output of the multi-detector array is input to an image reconstruction engine which combines the outputs of the multiple detectors over selected steps of the x-ray beam to generate an x-ray image of the object. A collimating element, preferably in the form of a perforated grid containing an array of apertures, interposed between the x-ray source and an object to be x-rayed. A maneuverable positioner incorporating an x-ray sensitive marker allowing the determination of the precise position coordinates of the maneuverable positioner.

Abstract: A measurement tool connects to an automatic inspection machine for measuring microscopic characteristics of features on a photographic mask. Widths of densely packed lines are measured for features having sizes of less than about the wavelength of the examining radiation. A simulated intensity profile is subtracted from the actual measured intensity profile to obtain an error profile. The error profile provides edge position corrections which adjust the originally estimated edge positions. A new, simulated intensity profile is created and the process is repeated until the error profile is deemed acceptable. The line width is measured by measuring between the estimated edge positions. The opacity of a feature is determined and used for correcting dimension measurements. A formula determines the opacity based upon the contrast, the measured dimension and the single data point. Width or height of an irregular feature is calculated accurately.

Abstract: A measurement tool connects to a microscope which may be an automatic inspection machine for identifying and measuring microscopic dimensions of features on a photographic mask such as opacity, area, diameter, width, height, line widths and corner radius. Dimensions of features having sizes of less than about twice the wavelength being used (less than 1 micron for visible light) are measured quickly and accurately in a production environment. The opacity of a feature is determined and used for correcting area or height measurements as well as helping to determine what the feature is made of. A contrast vs. diameter curve for known opaque features is used to determine opacity of unknown features. The curvature of the intensity profile of the feature is used in conjunction with a curvature-width lookup table in order to produce the width of the feature. Curvature-width lookup data is developed from the area and diameter of known round defects along with the curvature of the profile of the round defects.

Abstract: A measurement tool connects to a microscope for identifying and measuring microscopic dimensions of features on a photographic mask such as area, diameter and corner radius. Dimensions of features having sizes of less than about twice the wavelength being used (less than 1 micron for visible light) are measured quickly and accurately. The radius of curvature is also determined at submicron sizes using a flux measurement. Determination of the expected flux of a perfect comer aids in the measurement.

Abstract: A measurement tool connects to a microscope which may be an automatic inspection machine for identifying and measuring microscopic dimensions of features on a photographic mask such as opacity, area, diameter, width, height, line widths and corner radius. Dimensions of features having sizes of less than about twice the wavelength being used (less than 1 micron for visible light) are measured quickly and accurately in a production environment. The opacity of a feature is determined and used for correcting area or height measurements as well as helping to determine what the feature is made of. A contrast vs. diameter curve for known opaque features is used to determine opacity of unknown features. The curvature of the intensity profile of the feature is used in conjunction with a curvature-width lookup table in order to produce the width of the feature. Curvature-width lookup data is developed from the area and diameter of known round defects along with the curvature of the profile of the round defects.

Abstract: A measurement tool connects to an automatic inspection machine for identifying and measuring microscopic dimensions such as area, diameter, height and line width of defects and lines of a photographic mask. An operator draws a rough region of interest around a feature and the tool automatically identifies the feature and calculates its dimensions. For features less than one micron in size, the size of light photons interferes with measurement, so a non-linear polynomial calibration curve is developed for each machine. Features of known sizes are measured on a production machine to produce a calibration curve for each type of defect or line. Features of unknown sizes are measured on the same machine and the measured size in pixels are calibrated using the calibration curve to return a more accurate reading in microns.

Abstract: A measurement tool connects to an automatic inspection machine for identifying and measuring microscopic dimensions such as area, diameter, height and line width of defects and lines of a photographic mask. An operator draws a rough region of interest around a feature and the tool automatically identifies the feature and calculates its dimensions. For features less than one micron in size, the size of light photons interferes with measurement, so a non-linear polynomial calibration curve is developed for each machine. Features of known sizes are measured on a production machine to produce a calibration curve for each type of defect or line. Features of unknown sizes are measured on the same machine and the measured size in pixels are calibrated using the calibration curve to return a more accurate reading in microns.

Abstract: An x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array. The output of the multi-detector array is input to an image reconstruction engine which combines the outputs of the multiple detectors over selected steps of the x-ray beam to generate an x-ray image of the object. A collimating element, preferably in the form of a perforated grid containing an array of apertures, interposed between the x-ray source and an object to be x-rayed. A maneuverable positioner incorporating an x-ray sensitive marker allowing the determination of the precise position coordinates of the maneuverable positioner.

Abstract: An improved testing system and method for testing a flat-panel display is disclosed herein. A display is positioned under a high resolution camera for detection of, for example, brightness uniformity across the display. Errors in the detected image due to aliasing are avoided in the present invention by incrementally shifting the displayed image relative to the camera and detecting the displayed image at various shifted positions. A resulting accurate display can then be reconstructed by identifying those detector pixels generating a maximum signal. A single image may then be reconstructed using only those detected maximum pixel signals. The reconstructed image will be free of aliasing. The reconstructed image may then be analyzed electronically, and any anomalies in the pixels forming the display panel can then be accurately detected.

Abstract: An x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array. The output of the multi-detector array is input to an image reconstruction engine which combines the outputs of the multiple detectors over selected steps of the x-ray beam to generate an x-ray image of the object. A collimating element, preferably in the form of a perforated grid containing an array of apertures, interposed between the x-ray source and an object to be x-rayed. A maneuverable positioner incorporating an x-ray sensitive marker allowing the determination of the precise position coordinates of the maneuverable positioner.

Abstract: An x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array. The output of the multi-detector array is input to an image reconstruction engine which combines the outputs of the multiple detectors over selected steps of the x-ray beam to generate an x-ray image of the object. A collimating element, preferably in the form of a perforated grid containing an array of apertures, interposed between the x-ray source and an object to be x-rayed. A maneuverable positioner incorporating an x-ray sensitive marker allowing the determination of the precise position coordinates of the maneuverable positioner.

Abstract: An x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array. The output of the multi-detector array is input to an image reconstruction engine which combines the outputs of the multiple detectors over selected steps of the x-ray beam to generate an x-ray image of the object. A collimating element, preferably in the form of a perforated grid containing an array of apertures, interposed between the x-ray source and an object to be x-rayed. A maneuverable positioner incorporating an x-ray sensitive marker allowing the determination of the precise position coordinates of the maneuverable positioner.