Abstract: A method is disclosed for in-situ monitoring of an EUV mirror to determine a degree of optical degradation. The method may comprise the steps/acts of irradiating at least a portion of the mirror with light having a wavelength outside the EUV spectrum, measuring at least a portion of the light after the light has reflected from the mirror, and using the measurement and a pre-determined relationship between mirror degradation and light reflectivity to estimate a degree of multi-layer mirror degradation. Also disclosed is a method for preparing a near-normal incidence, EUV mirror which may comprise the steps/acts of providing a metallic substrate, diamond turning a surface of the substrate, depositing at least one intermediate material overlying the surface using a physical vapor deposition technique, and depositing a multi-layer mirror coating overlying the intermediate material.

Abstract: A metrology tool is arranged to measure a parameter of a substrate that has been provided with a pattern in a lithographic apparatus. The metrology tool includes a base frame, a substrate table, a sensor, a displacement system, a balance mass, and a bearing. The substrate table is constructed and arranged to hold the substrate. The sensor is constructed and arranged to measure a parameter of the substrate. The displacement system is configured to displace the substrate table or the sensor with respect to the other in a first direction. The bearing is configured to movably support the first balance mass so as to be substantially free to translate in a direction opposite of the first direction in order to counteract a displacement of the substrate table or sensor in the first direction.

Abstract: A surface inspecting apparatus can inspect a smaller defect by using a PSL of a smaller particle size. However, the particle size of the PSL is restricted. In the conventional surface inspecting apparatus, therefore, no consideration has been taken as to how to inspect the defect of such a small particle size as is not set in the PSL which will be needed in the near future in an inspection of a semiconductor manufacturing step. The invention has a light source device for generating light which simulated at least one of a wavelength, a light intensity, a time-dependent change of the light intensity, and a polarization of light which was scattered, diffracted, or reflected by an inspection object, and the light is inputted to a photodetector of the surface inspecting apparatus. The smaller defect can be inspected.

Abstract: A system for inspecting a specimen is provided. The system includes an illumination subsystem configured to produce a plurality of channels of light energy, each channel of light energy produced having differing characteristics (type, wavelength, etc.) from at least one other channel of light energy. Optics are configured to receive the plurality of channels of light energy and combine them into a spatially separated combined light energy beam and direct it toward the specimen. A data acquisition subsystem comprising at least one detector is provided, configured to separate reflected light energy into a plurality of received channels corresponding to the plurality of channels of light energy and detect the received channels.

Abstract: A method and apparatus for inspecting a defect of a surface of a sample in which a laser beam is irradiated on a sample surface so that at least a part of an illumination field of the laser beam illuminates a first area of the sample surface, a plurality of scattered light rays from the first area caused by the irradiation in the irradiating is detected, errors of inclination of an illumination apparatus and a sensor for the plurality of scattered light rays detected are corrected, the plurality of scattered light rays corrected is at least one of added and averaged, a defect on the sample surface based on the plurality of scattered light rays in accordance with the correcting of errors of inclination of the illumination apparatus and the sensor is determined.

Abstract: A surface-check equipment has a frame, at least one lamp fastened to the frame and at least one dark box fastened to the frame. The dark box has a case with a working side and a dark chamber. The working side has a slot defined through the working side and allowing light to enter the dark box via the slot. The dark chamber communicates with the slot and has an incident reflector, at least one transmitting reflector, a refractor assembly, at least one terminal reflector, and a sensor corresponding to each other and allowing light from the object via the slot to be reflected and refracted and received by the sensor. Therefore, the dark box has simple and inexpensive elements, so the surface-check equipment is easily and quickly assembled and has decreased cost and size.

Abstract: Provided are a surface inspection apparatus and method capable of detecting foreign materials on the surface of a substrate, and a slit coater having the surface inspection apparatus. In the surface inspection apparatus, a slit lighting unit irradiates slit-shaped light. An optical system splits the slit-shaped light into two beams traveling along two different paths, is incident upon a subject, and extracts an interference image caused by combination of the two beams reflected from the subject. An imaging device captures the interference image to output an image signal. An analysis unit acquires a luminance value of the image signal, analyzes the luminance value in real time, and determines whether or not foreign materials are present.

Abstract: When size of a defect on an increasingly miniaturized pattern is obtained by defect inspection apparatus in the related art, a value is inconveniently given, which is different from a measured value of the same defect by SEM. Thus, a dimension value of a defect detected by defect inspection apparatus needs to be accurately calculated to be approximated to a value measured by SEM. To this end, size of the defect detected by the defect inspection apparatus is corrected depending on feature quantity or type of the defect, thereby defect size can be accurately calculated.

Abstract: In a pattern-defect inspection method for inspecting a defect in an inspection pattern by comparing an image of the inspection pattern with an image of a reference pattern, inspection sensitivity is adjusted in accordance with the number of corner portion and so on of the reference pattern.

Abstract: The invention provides a surface inspection apparatus and a method for inspecting the surface of a sample that are capable of inspecting discriminatingly between the scratch of various configuration and the adhered foreign object that occur on the surface of a work target when the work target (for example, an insulating film on a semiconductor substrate) is subjected to polishing process such as CMP or grinding process in semiconductor manufacturing process or magnetic head manufacturing process.

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 method and apparatus of detecting a defect by inspecting a specimen in which a surface of a specimen on which plural patterns are formed is illuminated with an elongated shape light flux from one of plural directions which are different in elevation angle by switching an optical path of the light flux emitted from an illuminating light source in accordance with a kind of defect to be detected. Plural optical images of the specimen illuminated by the elongated shape light flux are captured with plural image sensors installed in different elevation angle directions by changing an enlarging magnification in accordance with a density of the pattern formed on the sample in an area irradiated with the illuminating elongated shape light flux. A defect on the specimen is detected by processing the images captured by the plural image sensors.

Abstract: A new architecture for machine vision system that uses area sensor (or line sensor), with telecentric imaging optics compound with telecentric illumination module is described. The illumination module may include a bright field illumination source and/or a dark field illumination source. The telecentric imaging optics includes an upper imaging module having an aperture stop and a lower imaging module positioned between the upper imaging module and object, such that the light source and the aperture stop are located in the back focal plane of the lower imaging module. The lower imaging module images the illumination source into a plane of an aperture stop of the upper imaging module. The optical axis of the upper imaging module is offset with respect to the lower imaging module. The optical axis of the telecentric illumination module is offset with respect to the axis of the lower imaging module in the opposite direction.

Abstract: Scattered light from the surface of a sample subjected to the same process as a process for an inspection object is observed, a defect is detected from an intensity of scattered light, and a position of the detected defect and an intensity of scattered light caused by the detected defect are acquired. Defects detected are classified into a group detectable by observing secondary electrons emitted when an electron beam is applied to the surface of the sample and a group not detectable. A decision threshold value of a scattered light intensity for extracting defects to be counted is determined, in accordance with a result of classification by the above steps and the intensity of scattered light caused by the detected defect.

Abstract: Inspection of EUV patterned masks, blank masks, and patterned wafers generated by EUV patterned masks requires high magnification and a large field of view at the image plane. An EUV inspection system can include a light source directed to an inspected surface, a detector for detecting light deflected from the inspected surface, and an optic configuration for directing the light from the inspected surface to the detector. In particular, the detector can include a plurality of sensor modules. Additionally, the optic configuration can include a plurality of mirrors that provide magnification of at least 100× within an optical path less than 5 meters long. In one embodiment, the optical path is approximately 2-3 meters long.

Abstract: The invention relates to a portable device (1) for the determination of surface properties with a measurement apparatus (10) which directly determines locally the topography of a surface (8) under investigation and issues at least one measured value that is characteristic of this local topography, and with a processor apparatus which, taking account of a multiplicity of initial measured values, issues at least one result value characteristic of the global topography of the surface.

Abstract: A pair of angular contact bearings 20A, 20B are disposed between a bearing house 16b of an inspection head 16 and a head supporting tube 8, and a spacer 25 and a spring bearing ring 26 are disposed between outer races 20o of the bearings 20A, 20B. The spacer 25 and the spring bearing ring 26 are urged by a coil spring 27 toward the side of the outer race 20o. An O-ring 28 is disposed between the spacer 25 and the outer race 20o of the bearing 20B, and the outer circumference of the O-ring is brought into closely contact with the inner circumference of the bearing house 16b. The outer races 20o are constrained by a step part 16f in the bearing house 16b and an end cap 29 screwed into the inspection head 16. Removing the end cap 29 makes it possible to take out the bearing housing 16b and a main shaft part 16c integrally from atop of the bearings 20A, 20B.

Abstract: A method for detecting defects on an object includes an illumination optical unit which obliquely projects a laser focused onto a line on a surface of the object and white-color, a table unit which mounts the specimen and which is movable, a detection optical unit which detects with an image sensor an image of light formed by light reflected from the object and passed through a filter which blocks diffraction light resulting from patterns formed on the object, a signal processor which processes a signal outputted from the image sensor of the detection optical unit to extract defects of the object, and a display unit which displays information of defects extracted by the signal processor. The filter is adjustable.

Abstract: A Pre-Aligned Metrology System comprising a number of Pre-Aligned Metrology Assemblies and Pre-Aligned Metrology Modules for measuring a target on a wafer. The Pre-Aligned Metrology Assemblies and Pre-Aligned Metrology Modules can reduce the maintenance down time and decrease the cost of ownership (COO).

Abstract: A laser beam oscillated from a laser source is folded in its path by first and second plane mirrors and enters a beam expander. The surface of each plane mirror is deteriorated with illumination by the laser beam and the reflectance is reduced. To avoid a light quantity of the laser beam entering the beam expander from being reduced below a reference value, when the laser beam is illuminated over a certain time, a position on each of the first and second plane mirrors at which the laser beam is illuminated is changed by a structure for rotating and/or translating a reflecting surface of each plane mirror on a plane, which includes the plane mirror, while an optical axis is kept same. Thus, the useful life of each plane mirror can be prolonged without displacing the optical axis.

Abstract: Various embodiments are directed to systems and methods of imaging subsurface features of objects. An illumination source may be directed towards a surface of an object comprising subsurface features at a first angle relative to the normal of the surface. The object may have a portion between the subsurface features and the surface that has an index of refraction that is greater than the index of refraction of a surrounding medium. An imaging device may be placed with an objective lens oriented substantially normal to the surface. The first angle may be larger than an acceptance angle of the objective lens.

Abstract: An optical metrology method is disclosed for evaluating the uniformity of characteristics within a semiconductor region having repeating features such a memory die. The method includes obtaining measurements with a probe laser beam having a spot size on the order of micron. These measurements are compared to calibration information obtained from calibration measurements. The calibration information is derived by measuring calibration samples with the probe laser beam and at least one other technology having added information content. In the preferred embodiment, the other technology includes at least one of spectroscopic reflectometry or spectroscopic ellipsometry.

Abstract: An inspection apparatus using a chip includes a rotor that holds a chip; a measurement room in which the rotor is provided and a through hole is formed; a light source that emits light for measurement to the chip through the through hole; a light measurement unit that detects the light from the chip, a rotation drive mechanism that rotates the rotor; and a cover member capable of covering or uncovering an opening portion.

Abstract: Glass inspection systems are provided for detecting particles and defects in or on a glass sheet or glass ribbon (2, 14). The system is mounted so that the surface (1) to be inspected is in the object plane of a reflective lens (10). The lens images a thin stripe area, long in the direction tangent to the lens circumference and short in the radial direction, onto a linescan camera (18). A line illuminator (12) can be mounted so that it illuminates the stripe area. To perform the inspection, the system is moved with respect to the glass in the direction perpendicular to the long axis of the stripe, either by moving the system over the glass or by moving the glass while the system is fixed. Image information is collected by the linescan camera during this motion and assembled into an image.

Abstract: An apparatus for the inspection of the heat shield of a space shuttle has a drive so that it can automatically undertake an examination of the tiles of the heat shield. The apparatus moves over the surface with the aid of the drive, and images of the region to be inspected are produced with the aid of a camera. For these images, the tiles are illuminated subsequently by light sources from different directions, as a result of which the tiles can be reliably evaluated with regard to possible defects.

Abstract: An inspection apparatus includes a captured image acquiring unit configured to acquire a captured image that is acquired by shooting an inspection target, an acquiring unit configured to acquire from the captured image a first image region and a second image region whose intensity distributions of reflected light with respect to an incident angle of illumination light emitted to the inspection target are different, and an image processing unit configured to perform image processing for performing different surface inspections on the first image region and the second image region respectively.

Abstract: Apparatus for generating optical radiation includes a laser, which is configured to operate in multiple transverse modes simultaneously so as to generate an input beam, which is characterized by a first speckle contrast. The transverse modes of the input beam are optically mixed so as to generate an output beam have a second speckle contrast, which is substantially less than the first speckle contrast.

Abstract: A defect inspection apparatus is capable of inspecting an extremely small defect present on the top and edge surfaces of a sample such as a semiconductor substrate or a thin film substrate with high sensitivity and at high speed. The defect inspection apparatus has an illumination optical system, a plurality of detection optical units and a signal processor. One or more of the detection optical units receives either light diffracted from an edge portion of the sample or light diffracted from an edge grip holding the sample. The one or more of the detection optical units shields the diffracted light received by the detection optical unit based on a signal obtained by monitoring an intensity of the diffracted light received by the detection optical unit in order to inspect a sample portion located near the edge portion and a sample portion located near the edge grip.

Abstract: The present invention relates to an operation stage of a charged particle beam apparatus which is employed in a scanning electron microscope for substrate (wafer) edge and backside defect inspection or defect review. However, it would be recognized that the invention has a much broader range of applicability. A system and method in accordance with the present invention provides an operation stage for substrate edge inspection or review. The inspection region includes top near edge, to bevel, apex, and bottom bevel. The operation stage includes a supporting stand, a z-stage, an X-Y stage, an electrostatic chuck, a pendulum stage and a rotation track. The pendulum stage mount with the electrostatic chuck has the ability to swing from 0° to 180° while performing substrate top bevel, apex and bottom bevel inspection or review.

Abstract: The present invention provides an apparatus and method which enable detecting a microscopic defect sensitively by efficiently collecting and detecting scattering light from a defect in a wider region without enlarging the apparatus. In the apparatus for inspecting a defect on a surface of a sample, including illumination means which irradiates a surface of a sample with laser, reflected light detection means which detects reflected light from the sample, and signal processing means which processes a detected signal and detecting a defect on the sample, the reflected light detection means is configured to include a scattering light detection unit which collects scattering light components of the reflected light from the sample by excluding specularly reflected light components by using an aspheric flannel lens and detecting the scattering light components.

Abstract: An apparatus for inspecting a specimen includes a first illumination unit having a laser light source and a first optical component for illuminating a specimen on which patterns are formed with a laser from a first elevation angle direction, a second illuminating unit having a light source and a second optical component for illuminating the specimen from a second elevation angle direction which is greater than the first elevation angle, a first detection optical unit which detects light from the specimen illuminated by the first illumination unit, a second detection optical unit which detects light from the specimen illuminated by the second illumination unit, and a signal processing unit which processes signals output from the first detector to detect defects in a first area on the specimen and processes signals output from the second detector to detect defects in a second area on the specimen.

Abstract: A device that is capable of simultaneously inspecting both sides of surfaces of a magnetic disk to detect defects thereon includes a front-side defect detecting section and a back-side defect detecting section each of which optically detect a scratch and a defect that are present on the front and back surfaces of the magnetic disk, to improve a throughput for inspection. The back-side defect detecting section has an optical path changing section that reflects a laser beam emitted by a laser light source to change an optical path thereof and thereby to direct the laser beam toward the back surface of the magnetic disk and that reflects scattered light that has been collected by a Fresnel lens to change an optical path thereof and thereby to direct the scattered light toward a first photoelectric converter.

Abstract: A method for inspecting a defect of a surface of a sample, includes irradiating a laser beam on the sample surface a plurality of times so that at least part of an illumination field of the laser beam on the sample surface illuminates a first area of the sample surface each of the plurality of times, detecting a plurality of scattered light rays from the first area caused by the plurality of times of irradiation, correcting errors of detection timings for the plurality of scattered light rays detected in the detection step, and determining a defect on the sample surface based on the plurality of scattered light rays in accordance with the correcting errors of detection timings.

Abstract: There is disclosed an inspection device for inspecting a spatial light modulator having a plurality of optical elements arrayed two-dimensionally and controlled individually, said inspection device comprising, a conjugate optical system which is arranged optically downstream the spatial light modulator and which forms a conjugate plane optically conjugate with an array plane where the plurality of optical elements are arrayed, a photodetector having a detection surface arranged on or near the conjugate plane, and an inspection unit which inspects optical characteristics of the plurality of optical elements, based on a result of detection by the photodetector.

Abstract: An optical metrology model is created for a structure formed on a semiconductor wafer. The optical metrology model comprises one or more profile parameters, one or more process parameters, and dispersion. A dispersion function is obtained that relates the dispersion to at least one of the one or more process parameters. A simulated diffraction signal is generated using the optical metrology model and a value for the at least one of the process parameters and a value for the dispersion. The value for the dispersion is calculated using the value for the at least one of the process parameter and the dispersion function. A measured diffraction signal of the structure is obtained. The measured diffraction signal is compared to the simulated diffraction signal. One or more profile parameters of the structure and one or more process parameters are determined based on the comparison of the measured diffraction signal to the simulated diffraction signal.

Abstract: The mask blank inspection apparatus is constituted of a stage for mounting a reflective mask blank thereon, a light source for generating inspection light, a mirror serving as an illuminating optics, an imaging optical system, a beam splitter, two two-dimensional array sensors, signal storage units, an image processing unit, a main control unit for controlling operation of the whole apparatus, the first sensor being located at a position which is displaced by a predetermined distance from the focal plane of a first light beam, the second sensor being located at a position which is displaced by a predetermined distance from the focal plane of a second light beam along a opposite direction, whereby accurately and conveniently inspecting presence/absence and types of defects in reflective mask blank.

Abstract: A method and apparatus for inspecting defects includes emitting an ultraviolet light from an ultraviolet light source, illuminating a specimen with the ultraviolet light in which a polarization condition of the ultraviolet light is controlled, controlling a polarization condition of light reflected from the specimen which is illuminated by the polarization condition controlled ultraviolet light, detecting the light reflected from the specimen, processing the detected light so as to detect defects, and outputting information about the defects. The ultraviolet light source is disposed in a clean environment supplied with clean gas and separated from outside.

Abstract: A defect inspection apparatus includes a movable stage for mounting a substrate having circuit patterns as an object of inspection, an irradiation optical system which irradiates a slit-shaped light beam from an oblique direction to the circuit patterns of the substrate, a detection optical system which includes an image sensor for receiving reflected/scattered light from the substrate by irradiation of the slit-shaped light beam and converting the received light into a signal, and an image processor which processes the signal. The irradiation optical system includes a cylindrical lens and a coherency reduction optical system, which receives the light beam and emits a plurality of slit-shaped light sub-beams which are spatially reduced in coherency in a light-converging direction of the cylindrical lens. The cylindrical lens focuses the plurality of slit-shaped light sub-beams into the slit-shaped light beam irradiated to the surface of the substrate.

Abstract: A substrate measuring stage used for a curve measuring system measuring a curve of the substrate and an ordinary measuring system measuring each of or one of a physical quantity and a chemical quantity of the substrate other than the curve, may include the mounting board movable between an ordinary measurement position for the ordinary measuring system and a retreat position away from and downward of the ordinary measurement position; the plurality of support pins insertable into through-holes provided in the mounting board and fixed to a curve measurement position for the curve measuring system; and a drive mechanism vertically moving the mounting board between the ordinary measurement position and the retreat position. The curve measurement position is set between the ordinary measurement position and the retreat position.

Abstract: Disclosed herein is a defect inspection apparatus including: a light source for emitting laser light; a mirror group for splitting the wave surface of incident laser light emitted by the light source into a plurality of component wave surfaces, arranging the component wave surfaces to form an array oriented in one direction and aligning the component wave surfaces to form a single wave surface after propagating the laser light through a moving object of measurement; an interferometer for splitting the single wave surface into two partial wave surfaces to create an interference stripe; an imaging section for taking an image of the interference stripe created by the interferometer; and an analysis section for detecting a defect existing on the surface of the moving object of measurement on the basis of changes of the image, which has been taken as the image of the interference stripe, with the lapse of time.

Abstract: The present invention is an apparatus for inspecting foreign particles/defects, comprises an illumination optical system, a detection optical system, a shielding unit which is provided in said detection optical system to selectively shield diffracted light pattern coming from circuit pattern existing on an inspection object and an arithmetic processing system, wherein said shielding unit comprises a micro-mirror array device or a reflected type liquid crystal, or a transmission type liquid crystal, or an object which is transferred a shielding pattern to an optical transparent substrate, or a substrate or a film which is etched so as to leave shielding patterns, or an optical transparent substrate which can be changed in transmission by heating, sudden cold, or light illumination, or change of electric field or magnetic field, or a shielding plate of cylindrical shape or plate shape.

Abstract: The invention is directed to a method for illuminating an object and projecting its image on a ground glass screen. Optical comparators conventionally use incandescent illumination, either mercury arc or halogen. The use of an array of high intensity LED devices, provides many options for packaging the required optical components used in comparators.

Abstract: Scatterometers making use of a Glan-laser polarizer are described. The use of Glan-laser polarizers as described generally results in an improved extinction ratio and use over a greater range of wavelengths when compared with dielectric polarizers.

Abstract: The present invention relates to an apparatus for detecting defects on a disk surface which projects light on the disk surface by a light transmitting system, receives specula reflection light and scattered light by a light receiving system, exposes defects by performing a two-dimensional frequency filter process on a signal, and performs a defect determination process to extract a linear-shaped isolative defect candidate. Next, the present invention performs a periodicity determination process to classify and detect the periodically generated linear and circular arc defects and the isolatively generated linear and circular arc defects.

Abstract: Selection with alignment marks of an optimal template, its identification and similarity judgment are conducted by a calculation function of a correlation value provided to a foreign matter inspection apparatus. In other words, the foreign matter inspection apparatus includes unit for registering feature points of alignment marks formed on a surface of an inspected object, unit for collecting image data of the alignment marks formed on the surface of the inspected object and a data processor for extracting a feature point from the image data and calculating a correlation value of both feature points, and registers the image data of the alignment mark on the basis of a threshold value of the correlation value.

Abstract: An inspection method of transparent articles wherein presence or absence of optical inhomogeneities within the transparent articles can be accurately inspected is provided. In an inspection method of transparent articles used in photolithography, for inspecting whether or not there are inhomogeneities within transparent articles (4) formed of transparent material wherein optical properties regionally or locally change with regard to exposure light (specifically, interior defects 16), inspection light having a wavelength of 200 nm or shorter is introduced to the transparent article, and light (15) having a longer wavelength than the inspection light which is regionally or locally emitted is sensed on the optical path over which the inspection light is propagated within the transparent article, thereby detecting presence or absence of optical inhomogeneities within the transparent article.

Abstract: A method for inspecting an object includes emitting light from at least one of a liquid crystal display (LCD) device and a liquid crystal on silicon (LCOS) device, phase-shifting light emitted from at least one of the LCD device and the LCOS device, projecting the phase-shifted light onto a surface of an object, receiving light reflected from the object surface with an imaging sensor, and analyzing the light received by the imaging sensor to facilitate inspecting at least a portion of the object.

Abstract: An inspection system includes imaging optics for imaging an object plane into an image plane. The imaging optics include an objective lens having positive optical power, a first lens group having negative optical power, and a second lens group having positive optical power. The optical elements are arranged along a common optical axis with a pupil plane of the imaging optics located between the first lens group and the second lens group.

Abstract: In an aspect, an inspection method for detecting the presence or absence of a defect on an object, the object comprising a recess having a physical depth, is disclosed. The method includes directing radiation at the object, the radiation having a wavelength that is substantially equal to twice an optical depth of the recess, detecting radiation that is re-directed by the object or a defect on the object, and determining the presence or absence of a defect from the re-directed radiation.

Abstract: A reticle defect inspection apparatus that controls damage of a reticle by irradiation with an inspection light when the reticle is caused to be at rest is provided. The reticle defect inspection apparatus is a reticle defect inspection apparatus for inspecting for defects on a reticle using a pattern image obtained by irradiating the reticle on which a pattern is formed with light. The reticle defect inspection apparatus has a dose monitoring part for measuring a dose of the light to the reticle, a comparing part for comparing, after calculating accumulated irradiation from the dose measured by the dose monitoring part, the accumulated irradiation with a preset threshold, and a stop mechanism for stopping irradiation of the reticle with the light when, as a result of the comparison, the accumulated irradiation exceeds the threshold.