Abstract: A system for precisely measuring layer-to-layer mis-registration is provided. The system includes a new type of mark and a comparison system, which compare the right and left signals from the mark to eliminate non-alignment noise, to enlarge the alignment information hundreds times then the actual shiftiness between two layers and to measure the mis-registration.

Abstract: A system and method for inspecting structures formed on the surface of an object using ultraviolet (UV) light. The object is placed in position and illuminated with at least one wavelength of UV light, directed at its surface from a UV source. At the moment of illumination, an image is captured by a UV-light sensitive camera positioned at an angle calculated to intercept light diffracted at particular an angle of diffraction associated with the pattern of structures formed on the surface of the object. To avoid having to repeatedly reposition the camera, one (or more in succession) illumination wavelength is selected to direct an intensity peak associated with a particular order of diffraction at the camera location. Ideally, a visible-light sensitive camera is also used to capture images of the surface when illumination with UV light results in the emanation of light in the visible portion of the spectrum.

Abstract: An optical inspection system and method for inspecting a component on a printed circuit board (PCB) which determines three-dimensional information in a single scan. A first visual light source illuminates the PCB surface and component with a green light while a second visual light source illuminates the PCB and component with a blue light. At least one laser light source simultaneously illuminates the surface of the PCB with a narrow coherent red-light laser beam. The laser light source is mounted off vertical on a movable mount which enables the laser beam to be directed over an area of interest on the surface of the PCB. The system also includes a color scan camera mounted vertically above the PCB. The camera has red, green, and blue channels. The green and blue channels capture an image of the illuminated surface of the PCB which is used by a computer to determine two-dimensional information about the component.

Abstract: A system for precisely measuring layer-to-layer mis-registration is provided. The system includes a new type of mark and a comparison system, which compare the right and left signals from the mark to eliminate non-alignment noise, to enlarge the alignment information hundreds times then the actual shiftiness between two layers and to measure the mis-registration.

Abstract: A system and method for performing optical inspection of structures on the surface of a semiconductor wafer. The wafer surface is illuminated with a polychromatic light source. A multiple-charged couple-device (CCD) camera is positioned to capture light diffracted by the structures on the wafer surface at the first order of diffraction. The captured light is then separated into a plurality of component wavelengths which are directed onto the CCDs. A digital filter creates a plurality of digitized diffractive images of the wafer surface at different component wavelengths. The diffractive images may be integrated and analyzed to detect defects in the structures, or may be, analyzed individually. An image at a particular wavelength may be selected and analyzed by using the known grating pitch of the structures to calculate the wavelength.

Abstract: A system and method for detecting defects in surface structures, such as those formed on semiconductor wafers. A light source, preferably a strobe light, provides illumination that is separated by a filter into a plurality of selected bandwidths. The light then is transported through a fiber optic cable to a diffuser, and from there directed toward the surface. A camera captures a plurality of images, each image formed by a separate portion of the electromagnetic spectrum. The images may be formed by either reflected or diffracted light, or both. The images may be stored or compared to an image of a calibration wafer.

Abstract: A method of collating and using captured semiconductor-wafer image data in an automated defect analysis. The method includes the steps of receiving image data and, if necessary, converting it to a digital format. Once the data is in pixel-by-pixel form, each pixel is assigned a slope value derived from the direction of the structure edge, if any, on which it lies. The pixel-slope data is then evaluated to determine whether a photo-resist anomaly is present. The method may also include evaluated an average pixel slope value for each inspected wafer. Dependant claims further define the invention to claim an inspection system for employing the method.

Abstract: A system and method of optically inspecting a structure on a surface of a production object which is supported on a moving inspection platform. The method reliably traces structure edges and stores structure and structure island characteristics. The system uses a camera and a light or energy source to sharply delineate the structure edges. A sequence of images of the object and the structure are captured, and the structure is detected in each image. The structure is then symbolically decomposed into primitives, and a histogram is produced for each image identifying the slope and length of each edge of the structure. The histograms are compared in each image, and are aligned to eliminate differences due to wobble of the inspection platform or differences in magnification. A production structure grammar is then produced from the aligned images. The production structure grammar is compared to a reference structure grammar generated from a defect-free object.

Abstract: A method and system for generating and managing a knowledgebase for use in identifying anomalies on a manufactured object, such as a semiconductor wafer, includes measures for adding, deleting, and organizing data from the knowledgebase.

Abstract: A system and method of optically inspecting structures on the surface of an object, such as a semiconductor wafer. A platform is used to support the object under examination, and provided thereat are lights or other energy sources for illumination disposed at a selected angular orientation. Optimum illumination is achieved by orienting two opposing lateral energy sources to direct energy along the surface of the object at a very low angle, and using them in conjunction with a coaxial light source that emits energy, which is directed downward toward the surface. Energy reflected back from the surface is captured as an image by a suitable device such as a CCD camera. The lighting may be controlled by an attached computer, which can also be used to process and store the captured image and analyze it to detect and catagorize defects in the object being inspected.

Abstract: A system and method allow for associating a descriptive label with an anomaly on a manufactured object, such as a semiconductor wafer. The method includes placing the manufactured device on a moveable stage; capturing and preparing a digital-pixel-based representation of the image; symbolically decomposing the digital-pixel-based representation of the image to create a primitive-based representation of the image; analyzing the primitive-based representation of the image to detect and locate the anomaly; isolating primitives associated with the anomaly; comparing the isolated primitives associated with the anomaly with primitives in a knowledge base to locate a set of primitives in the knowledge base most like the isolated primitives associated with the anomaly; and assigning a label associated with the set of primitives in the knowledge base that was most similar to the isolated primitives associated with the anomaly.

Abstract: A method and system for generating and managing a knowledgebase for use in identifying anomalies on a manufactured object, such as a semiconductor wafer, includes measures for adding, deleting, and organizing data from the knowledgebase.

Abstract: An apparatus, system, and method of optically inspecting printed circuit boards (PCBs) for defects, that reliably determines the dimensions of components including those having the same color as the background, and which can detect components which are missing, misoriented, misaligned, or not properly seated. The apparatus uses a camera and a coherent primary light source mounted at an angle away from the vertical so as to produce sharply defined PCB component shadows on the top surface of the PCB. An image of the PCB is captured, the shadow edges are symbolically decomposed into primitives from which gradients are produced, and then compared to a previously captured gradient of a defect-free PCB. Differences in the two image gradients, if any, are used to identify missing, misaligned, misoriented, and improperly seated components, and to detect foreign objects and other PCB defects.

Abstract: A system and method for repairing a defect on a manufactured object, which may be a semiconductor wafer, uses a computer and a repair tool.

Abstract: A system and method for detecting anomalies on a manufactured device includes or utilizes a moveable stage for holding and positioning the device, a camera for capturing an image of the device on the stage, a digitizer coupled to the camera for producing a digital-pixel-based representation of the image, and a computer having a processor and memory. The computer is coupled to the digitizer for receiving the digital-pixel-based representation from the digitizer and coupled to the stage for selectively moving the stage to align the device. The computer is programmed to be operable to symbolically decompose a digital-pixel-based representation of an image to create a primitive-based representation of the image. The image may be aligned by the computer with respect to the rotation of geometric objects in the image by developing a histogram of angles and lengths and matching them to determine a rotational shift.

Abstract: An apparatus and method for automatic knowledge-based object or anomaly classification is provided by capturing a pixel map of an image and from that generating high level descriptors of the object or anomaly such as size, shape, color and sharpness. These descriptors are compared with sets of descriptors in a knowledge-base to classify the object or anomaly.

Abstract: A method involves capturing visual indicia as a digital image, isolating the visual indicia on the digital image, converting the visual indicia to image primitives, identifying and presenting the visual indicia. An apparatus contains a camera for capturing a visual image, a video-to-digital converter, and a computer with a processor, appropriate memory, and software.

Abstract: A method is provided for aligning a silicon wafer (20) in a fabrication tool (37) having a stage (22) involving the steps of producing a digital image of a portion of wafer (20) in a scope-of-view window (48), converting the digital image to image primitives, comparing the image primitives to grammar template primitives to locate a known intersection on wafer (20); and moving the stage (22) to align wafer (20). A method and apparatus are disclosed for determining the misregistration of two layers of a wafer (20) by converting targets (158, 160) to primitives and determining the relative displacement in symbolic space. The misregistration apparatus involves a camera (34), a video-to-digital converter (32), a computer (28), and a stage adjuster (24).

Abstract: A method and apparatus for reading visual indicia is disclosed. The method involves capturing the visual indicia as a digital image, isolating the visual indicia on the digital image, converting the visual indicia to image primitives, identifying the identified visual indicia, and presenting the visual indicia. The apparatus contains a camera for capturing a visual image, a video-to-digital converter, and a computing means.

Abstract: A method and apparatus (62) for processing images in symbolic space are disclosed. The method may include the steps of capturing a visual image (40), converting the visual image to a digital image (42), decomposing the digital image into image primitives (44), and processing the image primitives in symbolic space (46). The processing of the image primitives may include grouping the image primitives to form higher level image primitives, isolating portions of an image, filtering noise, identifying portions of an image, or adding to a knowledge base. The system or apparatus (62)for processing an image in symbolic space may include a camera (64), a video-to-digital converter (66), and a computer (68) with appropriate memory and software; the processing may include grouping the image primitives to form higher level image primitives, isolating portions of an image, filtering noise, identifying portions of an image, or adding to a knowledge base.