Abstract: A pattern defect inspection apparatus capable of detecting minute defects on a sample with high sensitivity without generating speckle noise in signals is realized. Substantially the same region on a surface of a wafer is detected by using two detectors at mutually different timings. Output signals from the two detectors are summed and averaged to eliminate noise. Since a large number of rays of illumination light are not simultaneously irradiated to the same region on the wafer, a pattern defect inspection apparatus capable of suppressing noise resulting from interference of a large number of rays, eliminating noise owing to other causes and detecting with high sensitivity minute defects on the sample without the occurrence of speckle noise in the signal can be accomplished.

Abstract: A defect inspection apparatus includes: stages each mounting an inspecting object on which a circuit pattern having a group of parallel lines is formed, and each running perpendicular or parallel to the group of lines; an illumination optical system which illuminating a surface of the inspecting object with a slit beam being slit light so that a longitudinal direction of the slit beam is substantially perpendicular to the running directions of the stages, and which has a first inclined angle formed by the direction of the group of lines and a projection line, of an optical axis of the slit beam, to the inspecting object; a spatial filter that shields or transmits reflected and scattered light of the inspecting object according to a difference in distribution of orientation; and a detection optical system that detects the reflected and scattered light transmitted through the spatial filter by image sensors.

Abstract: A visual inspection apparatus includes an image-data acquisition unit for acquiring plural pieces of image data A to C on an inspection target, image comparison units for comparing the image data A to C with each other thereby to create plural pieces of sign-affixed difference-image data D and E, the image data A to C being acquired by the image-data acquisition unit, difference-image comparison units for determining the difference between the sign-affixed difference-image data D and E created by the image comparison units, and a judgment unit for subjecting, to a threshold-value processing, difference data F between the difference-image data D and E, the difference data F being acquired by the difference-image comparison units, obtaining a detection sensitivity by enlarging the difference between an abnormal signal level of an image of an area where an abnormality exists from the visual inspection.

Abstract: A defect inspection apparatus includes: stages each mounting an inspecting object on which a circuit pattern having a group of parallel lines is formed, and each running perpendicular or parallel to the group of lines; an illumination optical system which illuminating a surface of the inspecting object with a slit beam being slit light so that a longitudinal direction of the slit beam is substantially perpendicular to the running directions of the stages, and which has a first inclined angle formed by the direction of the group of lines and a projection line, of an optical axis of the slit beam, to the inspecting object; a spatial filter that shields or transmits reflected and scattered light of the inspecting object according to a difference in distribution of orientation; and a detection optical system that detects the reflected and scattered light transmitted through the spatial filter by image sensors.

Abstract: The invention is directed to find a false defect from defect candidates and obtain a threshold with which the false defect can be eliminated by the smallest number of review times. Defect candidates are reviewed and selected as a defect or a false defect. By deleting a defect candidate having a characteristic quantity equal to or less than that of the false defect from a map or displaying it in another sign, the false defect can be determined visually. Since the defect candidate having the characteristic quantity equal to or less than that of the selected false defect is deleted from the map or displayed in another sign, the defect candidates unnecessary to set a threshold are not reviewed. The number of defect candidates to be reviewed can be largely reduced as compared with that in the conventional technique. Further, by repeating the above work, the threshold is automatically calculated, and an inspection result map with the threshold is displayed, so that a re-inspection is unnecessary.

Abstract: A pattern defect inspection apparatus capable of detecting minute defects on a sample with high sensitivity without generating speckle noise in signals is realized. Substantially the same region on a surface of a wafer is detected by using two detectors at mutually different timings. Output signals from the two detectors are summed and averaged to eliminate noise. Since a large number of rays of illumination light are not simultaneously irradiated to the same region on the wafer, a pattern defect inspection apparatus capable of suppressing noise resulting from interference of a large number of rays, eliminating noise owing to other causes and detecting with high sensitivity minute defects on the sample without the occurrence of speckle noise in the signal can be accomplished.

Abstract: A defect inspection apparatus includes: stages each mounting an inspecting object on which a circuit pattern having a group of parallel lines is formed, and each running perpendicular or parallel to the group of lines; an illumination optical system which illuminating a surface of the inspecting object with a slit beam being slit light so that a longitudinal direction of the slit beam is substantially perpendicular to the running directions of the stages, and which has a first inclined angle formed by the direction of the group of lines and a projection line, of an optical axis of the slit beam, to the inspecting object; a spatial filter that shields or transmits reflected and scattered light of the inspecting object according to a difference in distribution of orientation; and a detection optical system that detects the reflected and scattered light transmitted through the spatial filter by image sensors.

Abstract: In the case of die-to-die comparison, threshold processing units process the differential image between the image of a sample chip and the images of left and right adjacent chips using a second threshold value lower than a first threshold value thereby to determine a defect candidate for the sample chip. Further, threshold processing units process the differential image using the first threshold value. The defect candidates which develops a signal not smaller than the first threshold is detected as a defect. Also in the cell-to-cell comparison, the differential image is first processed by the second threshold value to determine a defect candidate, and the differential image is further processed by the first threshold value. The defect candidates which develops a signal not smaller than the first threshold value is detected as a defect.

Abstract: An apparatus is provided which reduces the dependency of the direction of polarization on channels of an image sensor so as to improve the sensitivity of inspection. In the apparatus, the direction of an illumination beam incident on a polarizing beam splitter is made to be substantially parallel to the longitudinal direction of a field of view of an image sensor projected on the polarizing beam splitter.

Abstract: In order to detect defects without reducing the inspection speed, even when inspection is made by acquiring a high magnification image, defect inspection method is provided in which a surface of a sample is illuminated, via an illumination optical system, with light emitted by an illumination light source, an image of the sample illuminated with the light is picked up via a detection optical system, and the picked up image of the sample is compared with a previously stored image to detect defects. In illuminating the sample with the light, the area of the sample to be illuminated is varied according to an imaging magnification of the detection optical system.

Abstract: A non-polarization beam splitter is used for splitting optical paths of an illumination system and an image formation system. MTF characteristics independent of an orientation of a pattern on a sample is obtained by illumination with a circularly-polarized light by combining a polarizer and a ?/4 plate. A partial polarizer is put in the image formation system immediately after the non-polarization beam splitter, and high-order diffraction lights are taken in with the maximum efficiency and the transmission efficiency of the zero-order light is controlled to improve high frequency part of MTF.

Abstract: A visual inspection apparatus includes an image-data acquisition unit for acquiring plural pieces of image data A to C on an inspection target, image comparison units for comparing the image data A to C with each other thereby to create plural pieces of sign-affixed difference-image data D and E, the image data A to C being acquired by the image-data acquisition unit, difference-image comparison units for determining the difference between the sign-affixed difference-image data D and E created by the image comparison units, and a judgment unit for subjecting, to a threshold-value processing, difference data F between the difference-image data D and E, the difference data F being acquired by the difference-image comparison units, obtaining a detection sensitivity by enlarging the difference between an abnormal signal level of an image of an area where an abnormality exists from the visual inspection.

Abstract: An apparatus and method for reproducing signals from a multi-layer structured recording object wherein a linearly polarized laser beam illuminate the multi-layer structured object, such as a phase change recording medium via an objective lens system having an effective numerical aperture greater than 0.6. A light beam reflective from the object is passed to a filtering mask disposed to receive the reflected light beam. The filtering mask includes a first area that has a first transmissivity and a second area having a second transmissivity different than the first transmissivity. The reflected laser beam passed through the filtering mask is detected to reproduce signals from the recording medium.

Abstract: The present invention provides a step difference detection apparatus including an illumination section for emitting illumination light, an incident section for making the illumination light emitted by the illumination section be incident on a plurality of small illumination regions on an object carried in a predetermined carrier direction from different directions, an image sensing section for inputting an image of the regions on the object illuminated with the illumination light which is made to be incident by the incident section, and a detection section for detecting a step difference on the object on the basis of the image sensed by the image sensing section.

Abstract: The present invention provides a step difference detection apparatus including an illumination section for emitting illumination light, an incident section for making the illumination light emitted by the illumination section be incident on a plurality of small illumination regions on an object carried in a predetermined carrier direction from different directions, an image sensing section for inputting an image of the regions on the object illuminated with the illumination light which is made to be incident by the incident section, and a detection section for detecting a step difference on the object on the basis of the image sensed by the image sensing section.

Abstract: A backlighting apparatus for radiating light on a flat surface to be illuminated comprises a light source having a linear light emitting portion, a light shield section, provided along an outer periphery of the light source on the side of the to-be-illuminated surface, for shielding light traveling directly from the light source toward the to-be-illuminated surface, and a first optical element provided in a longitudinal direction of the light source such that the first optical element faces the light source, the first optical element having a reflection surface for reflecting light emitted from the light source toward the to-be-illuminated surface. A cross-sectional shape of the reflection surface in a direction perpendicular to the longitudinal direction of the light source is determined such that light reflected by the reflection surface of the first optical element has a substantially uniform illuminance distribution on the to-be-illuminated surface.

Abstract: A projection display apparatus includes a light source, a spatial light modulation device, a condenser lens, an aperture stop, and a projecting lens. When the spatial period of complex amplitude modulation in the spatial light modulation device is represented by p, the center wavelength of the incident light is represented by .lambda., and a half angle subtended by an area around an opening edge of the aperture stop at the condenser lens along the first direction is represented by .theta.asx, parameters of the light source, the spatial light modulation device, the condenser lens, the screen, the aperture stop and the projecting lens and a relative positional relationship therebetween are defined such that the following condition is satisfied:0.35<.theta.asx/arcsin(.lambda./p)<0.6.

Abstract: An optical disk apparatus includes a semiconductor laser for emitting a light beam, and an automatic power control or APC circuit for driving the laser. A compound prism structure is optically coupled to the laser in an optical head section, and defines a first optical path for causing a front laser light to be projected onto a rotating optical disk and guiding a reflected light therefrom toward a first photodetector, and a second optical path for guiding a part of the reflected light toward a second photodetector. An output signal of the first photodetector is used to generate a reproduced information signal. An output signal of the second photodetector is fed back to the APC circuit as a front light monitor signal. A part of a laser control signal internally generated in the APC circuit is supplied through a wiring line to a noise reduction circuit as a laser noise monitor signal.

Abstract: An optical disk apparatus includes a semiconductor laser for emitting a light beam, and an automatic power control or APC circuit for driving the laser. A compound prism structure is optically coupled to the laser in an optical head section, and defines a first optical path for causing a front laser light to be projected onto a rotating optical disk and guiding a reflected light therefrom toward a first photodetector, and a second optical path for guiding a part of the reflected light toward a second photodetector. An output signal of the first photodetector is used to generate a reproduced information signal. An output signal of the second photodetector is fed back to the APC circuit as a front light monitor signal. A part of a laser control signal internally generated in the APC circuit is supplied through a wiring line to a noise reduction circuit as a laser noise monitor signal.

Abstract: The present invention provides a method and apparatus for producing a hologram from a series of two-dimensional images horizontally different in line of sight from each other. The holographic apparatus employs original images produced by photographing an object from different directions, an object optical system which makes a light be incident upon original image to project an object beam onto photo-sensitive material, and a reference optical system which projects a reference beam of a same wavelength as the object beam toward the photo-sensitive material. The horizontal component of the object beam can be converged at a rear point i.e., a point of view at image reproduction, relatively distant from the photo-sensitive material on which a hologram is produced. When the hologram is reconstructed, a beam having the same wavelength as when recorded is converged at the rear point of view, so that the reconstructed image can be viewed in a same color free from any color shading.