Abstract: A semiconductor based radiation detector utilizing a dual absorption layer system design to selectively respond to particular bands of incident radiation while rejecting others. Generally, a top absorption layer initially absorbs all radiation less than a cutoff wavelength. Radiation longer than the cutoff pass to a buried or second absorption layer. This second absorption layer has a smaller band gap energy corresponding with a larger cutoff wavelength than the top layer and is therefore responsive to longer wavelengths or radiation with lower energies. As such, preselected wavelengths or energy bands are detectable by the second layer while all other wavelengths or energy bands are either absorbed by the top layer or passed through both layers. The resultant absorption in the second layer is thereafter detectable to indicate the presence of the desired wavelength.

Abstract: This invention relates to an exposure apparatus for synchronously scanning a mask and a photosensitive substrate with respect to a plurality of projection optical systems, thereby properly transferring an entire pattern area on the mask onto the photosensitive substrate. A plurality of sets of mask-side reference marks and substrate-side reference marks are arranged at positions corresponding to each other on the mask surface and the photosensitive substrate surface and at least at two positions conjugate with the plurality of projection optical systems. The displacement amount between an image of a mask-side reference mark or a substrate-side reference mark formed on the corresponding substrate-side reference mark or mask-side reference mark through the projection optical system and the position of the substrate-side reference mark and the mask-side reference mark is measured. The imaging characteristics of the plurality of projection optical systems are corrected in accordance with the displacement amount.

Abstract: A pair of masks is designed to expose an upper surface and a lower surface of a silicon wafer. Each mask includes, outside its operative surface area, corresponding to the surface of the silicon wafer, identical or complementary sighting marks.

Abstract: A surface position detecting apparatus is suitable for detecting a position of a surface of the substrate supported by a support means in an exposure apparatus. The surface position detecting apparatus comprises a light source, an irradiation optical system for irradiating light from the light source obliquely onto the substrate surface and forming an image of a measurement pattern of a pattern plate on the substrate surface, and a converging optical system for converging light irradiated from the irradiation optical system and then reflected by the substrate surface to re-image the image of the measurement pattern on a photodetector surface. The photodetector can detect the surface position based on the position of pattern image re-imaged on the photodetector surface. The image of the measurement pattern comprises a linear image extending in a predetermined direction.

Abstract: A registration method is usable with projection optical system for projecting first and second patterns of a first object simultaneously upon a second object having a surface step, for measuring at different locations the surface position of the second object with respect to the direction of an optical axis of the projection optical system prior to the pattern projection to bring the surface of the second object into coincidence with an image plane of the projection optical system on the basis of the measurement, wherein the first pattern has a smaller depth of focus than that of the second pattern. The method includes bringing the surface position of the second object, at the location whereat the first pattern is to be projected, into coincidence with the image plane of the projection optical system; and correcting any tilt of the surface of the second object with respect to the image plane of the projection optical system.

Abstract: Two-colored illumination light emitted from first and second laser beam sources illuminates a reticle mark and a wafer mark. Diffraction light from the reticle mark and the wafer mark is received by two photoelectric detection elements, respectively. The one photoelectric element receives single-colored diffraction light from light of the first light source through a color filter to generate a reticle beat signal. The other photoelectric element receives two-colored light to generate a wafer beat signal. A phase difference between the reticle beat signal and the wafer beat signal when shutting off the second laser beam source is aligned with a phase difference between the two signals produced when turning on the second laser beam source and decreasing the power of the first laser light source.

Abstract: Through-the-lens alignment during deep UV lithographic processing in the manufacture of VLSI is accomplished without shifting the mask or wafer from the exposure position. Introduction and extraction of alignment light of actinic wavelength depends on beam routing due to diffraction from an interference grating. The path of alignment light is within the focusing system but does not impinge on the focused pattern.

Abstract: Measured is a coordinate position, on a static coordinate system, of each of some specified areas selected from a plurality of areas on a substrate. The coordinate positions of some specified areas undergo a weighted averaging process by use of such a weight that it decreases with a larger distance between the specified areas. The coordinate position is thereby smoothed per specified area. The weight is given to each of some smoothed coordinate positions, and, thereafter, a statistic calculation is effected. The coordinate position, on the static coordinate system, of the area on the substrate is thereby obtained. The substrate is sequentially located based on the obtained coordinate position, and each area on the substrate is thus aligned to a predetermined position.

Abstract: A position detecting method includes illuminating a grating mark of an object with monochromatic light; forming an interference image on an image pickup device by using .+-. n-th order light (n=1, 2, 3 . . . ) among reflective diffraction light from the grating mark; integrating an image signal produced by the image pickup device within a two-dimensional window of a predetermined size set with respect to the image signal and along one direction in two-dimensional coordinates, whereby a one-dimensional projection integration signal is produced; transforming, through rectangular transformation, the one-dimensional projection integration signal into a spatial frequency region; selecting, on the spatial frequency region and from the one-dimensional projection integration signal, a spatial frequency component which appears in the interference image due to the periodicity of the grating mark; and detecting the position of the grating mark on the basis of the selection.

Abstract: A surface position detection apparatus includes a projection optical system for projecting pattern light having a predetermined pattern on a detection surface from an oblique direction to the detection surface, an imaging optical system for forming an image of the pattern light reflected by the detection surface, a light-receiving-side light-shield arranged at a position substantially conjugate with the detection surface in the imaging optical system, and having an opening portion with a predetermined shape, a scanner for scanning the pattern image formed by the imaging optical system relative to the light-receiving-side light-shield, and a detection device for the pattern light into a plurality of portions, and selectively detecting at least one such portion of the pattern light.

Abstract: A method and apparatus for measuring the relative positional deviation between first and second diffraction gratings formed on an object includes determining the relative positional deviation of the first and second diffraction gratings while detecting and correcting an error produced in relation to detection of the positional deviation of the first and second diffraction gratings.

Abstract: An alignment method for successively aligning a plurality of alignment areas of a plurality of successively supplied substrates with predetermined reference positions, includes four processes. The first process measures the positions of the alignment areas of at least a leading one of the substrates with respect to preassigned positions of the alignment areas comprising a preassigned arrangement of the alignment areas to obtain the actual arrangement of the alignment areas. The second process determines conversion parameters, such that when the relationship between the actual arrangement of alignment areas and the preassigned arrangement of alignment areas obtained in the first process is represented by a conversion formula including the conversion parameters and a correction remainder representing the error in the actual arrangement as compared to the preassigned arrangement, the error becomes a minimum.

Abstract: A projection exposure apparatus includes an illumination system for illuminating a mask, on which a pattern to be transferred is formed, with exposure light, a projection optical system for imaging and projecting the pattern on the mask onto a photosensitive substrate, beam radiation means for radiating an alignment beam with a wavelength different from the wavelength of the exposure light toward a first grating mark formed on the mask and a transparent portion near the first grating mark, and radiating the alignment beam onto a second grating mark formed on the photosensitive substrate via the transparent portion and the projection optical system, the beam radiation means having a four-beam generation member for generating two first alignment beams which cross each other on the first grating mark, and two second alignment beams which cross each other in a space separated by a predetermined distance from the surface of the mask.

Abstract: An exposure apparatus comprises a plurality of illumination optical systems for generating a plurality of light beams, a plurality of projection optical systems disposed corresponding to the plurality of illumination optical systems, respectively, a plurality of light intensity detectors, provided respectively for the plurality of illumination optical systems, for detecting individual intensities of the plurality of light beams, a light intensity changing device for changing the respective intensities of the plurality of light beams, and a control device for controlling the light intensity changing device and uniformizing the intensities of the plurality of light beams to a substantially fixed level.

Abstract: A scanning light exposure apparatus comprises illumination optical systems for radiating light beams to a plurality of sub-areas in a pattern area of a mask, a plurality of projection optical systems arranged along a predetermined direction for projecting erected images of unity magnification of the sub-areas by the light beams transmitted through the mask onto a photo-sensitive substrate, a diaphragm member arranged at a substantially conjugate position to the photo-sensitive substrate in each illumination optical system for limiting a projection area of the sub-area to the photo-sensitive substrate, scanning means for synchronously scanning said mask and said photo-sensitive substrate substantially transversely to the predetermined direction relative to said projection optical systems and diaphragm control means for changing a width of an aperture of each diaphragm member along a direction transverse to the predetermined direction.

Abstract: A position detecting apparatus for optically observing an opaque mark formed on a transparent substrate to detect a position of the mark with a high degree of accuracy. The apparatus includes a detection optical system for forming a detected image of the mark, an illumination system for supplying an illuminating light to the mark through an objective lens of the detection optical system, projection means arranged to face the detection optical system through the substrate and forming a conjugate position to the mark, and reflecting means which is settable substantially at the conjugate position. The image of the mark can be detected as either a bright image or a dark image under the conditions where there are a sufficient contrast between the mark and the background and a uniform background density. The shape of the mark and the arrangement of patterns around the mark can be determined as desired.

Abstract: An exposure apparatus according to the present invention comprises a projection optical system for transferring a pattern of an image on a mask onto a photosensitive substrate, a plurality of alignment optical systems for independently detecting a plurality of alignment marks provided at least on said mask and detecting associated alignment marks through respective objective lenses provided corresponding thereto, and a variable optical system for obtaining a reduced image of the mask, set between a first plane on which the mask is to be located and a second plane which is parallel to the first plane and on which the objective lenses are to be located. Particularly, the variable optical system is so designed as to avoid overlap of beams entering the respective objective lenses provided for the alignment optical systems upon observation of the associated alignment marks through the respective alignment optical systems.

Abstract: A position detecting apparatus comprises a double-beam producing device for producing two beams different in frequency from each other, which are guided to irradiate a diffraction grating on an object to be inspected in two predetermined directions, and a detector photoelectrically detecting through an objective optical system diffracted light produced by the diffraction grating, in which the double-beam producing device comprises a light source for supplying a beam of a single wavelength or multiple wavelengths, a beam splitting device for splitting the beam from the light source into two predetermined beams, a relay optical system for converging the two split beams at a predetermined position, and a frequency difference producing device disposed at or near a converging position by the relay optical system, for producing a predetermined frequency difference between the two split beams.

Abstract: To detect the height position of a substrate, a stop-plate having a plurality of slits applies light beams of elongated cross-section to the substrate obliquely. A sensor having a plurality of sensor elements receives light beams reflected from the substrate and outputs signals for controlling the height of the substrate. Additional light beams and sensor elements may be provided to output information regarding the direction of height deviation and the amount of height deviation.

Abstract: The present invention relates to a light-exposure assembly. It includes a mask which is placed on a mask stage to accept exposed light. A work-piece stage is placed under the mask stage. A projection lens is placed in between the mask stage and the work-piece stage to form an image on the work-piece stage by accepting the exposed light. A first mark is carved on the mask to detect the parallel-degree of movement of the mask stage and the work-piece stage. A second mark is carved on the mask to measure changes in magnification of a projection lens by moving together the above first mark. A third mark is carved on the mask to determine focus point of the projection lens. A fourth mark is carved on the work-piece stage to assist the first and second marks. A first optical detecting part is placed on the work-piece stage, on which a fourth mark is carved to assist the movement of the first and second marks, and to detect the exposed light.

Abstract: The present invention provides a grating-grating interferometric wafer alignment system, sensor and method for microlithography. It includes: (1) an electromagnetic radiation source with collimating optics delivering a collimated beam of a coherent single or multiple discrete wavelengths or in some cases broadband electromagnetic radiation; (2) a detector of the intensity of the collimated return electromagnetic radiation; (3) x- and y-oriented independent linear gratings for the mask-mark; (3) a "checkerboard pattern" grating for the wafer-mark; and (4) software including an algorithm for determining alignment from the return electromagnetic radiation intensity measured as a function of the relative position of the wafer and mask grating, and a means such as a Fourier transform determining phase and amplitude of a known frequency component of the intensity.

Abstract: An interval detection method for detecting the interval between two marks provided on the surface of a wafer with high accuracy using other two marks provided on the wafer, and a method for detecting the relative positions of a wafer and a mask with high accuracy are provided.

Abstract: An interferometer used to measure distance to an object is provided with a laser sheath. The sheath encloses a substantial part of the measurement beam's path to provide a controlled environment which reduces environmental influences on the measured distance. The sheath is of variable length and responsive to a follower so as to maintain a sheath end nearest the object at a small distance from the object. An environmental controller controls the environment within the sheath. The environment within the sheath can be a vacuum or a suitable gas or gas mixture. A corrector can be used to compensate the interferometer's measured-distance signal for detected environmental characteristics to produce a corrected signal which indicates distance between the interferometer and the reflective surface. The apparatus and methods can be used to measure and control stage position in a projection-type wafer exposure system which is affected by variations in its atmospheric environment.

Abstract: An illumination optical system and an alignment apparatus suitable for reticle alignment in the projection exposure apparatus. There is provided an illumination optical system having parallel beam supply means for supplying a parallel beam and a light guide for guiding the parallel beam from the parallel beam supply means to a target illumination object, comprising diffusion means, arranged between the parallel beam supply means and the light guide, for diffusing the parallel beam, wherein an incident end face of the light guide is arranged to be inclined by a predetermined angle with respect to a plane perpendicular to a direction of incidence of the parallel beam onto the diffusion means.

Abstract: A deviation detecting system for detecting a rotational deviation of an object, includes a pattern formed on the object and having a periodicity, a light source for providing light, a detecting device for projecting the light from the light source onto the pattern and for detecting at least two diffraction lights from the pattern with a predetermined detection plane, and a determining device for determining a rotational deviation of the object with respect to a predetermined axis, on the basis of the positions of incidence of the diffraction lights upon the detection plane as detected through the detection by the detecting device.

Abstract: An aligning method suitably usable in a semiconductor device manufacturing exposure apparatus of step-and-repeat type, for sequentially positioning regions on a wafer to an exposure position. In one preferred form, the marks provided on selected regions of the wafer are detected to obtain corresponding mark signals and then respective positional data related to the positions or positional errors of the selected regions are measured, on the basis of the mark signals. Then, the reliability of each measured positional data of a corresponding selected region is detected, on the basis of the state of a corresponding mark signal or the state of that measured positional data and by using fuzzy reasoning, for example.

Abstract: A projection aligner transfers a pattern image of a reticle by using a light radiated from a light source through a diaphragm to a photo-resist layer, and the position of the light source is automatically regulated on the basis of pieces of illuminance data simultaneously measured on an image forming plane so that the regulation is exact and completed within a short time period.

Abstract: A position detecting apparatus comprises a double-beam producing device for producing two beams different in frequency from each other, which are guided to irradiate a diffraction grating on an object to be inspected in two predetermined directions, and a detector photoelectrically detecting through an objective optical system diffracted light produced by the diffraction grating, in which the double-beam producing device comprises a light source for supplying a beam of a single wavelength or multiple wavelengths, a beam splitting device for splitting the beam from the light source into two predetermined beams, a relay optical system for converging the two split beams at a predetermined position, and a frequency difference producing device disposed at or near a converging position by the relay optical system, for producing a predetermined frequency difference between the two split beams.

Abstract: A position detecting apparatus comprises a double-beam producing device for producing two beams different in frequency from each other, which are guided to irradiate a diffraction grating on an object to be inspected in two predetermined directions, and a detector photoelectrically detecting through an objective optical system diffracted light produced by the diffraction grating, in which the double-beam producing device comprises a light source for supplying a beam of a single wavelength or multiple wavelengths, a beam splitting device for splitting the beam from the light source into two predetermined beams, a relay optical system for converging the two split beams at a predetermined position, and a frequency difference producing device disposed at or near a converging position by the relay optical system, for producing a predetermined frequency difference between the two split beams.

Abstract: A scanning exposure apparatus according to the present invention comprises a reticle stage for continuously moving a reticle and a wafer stage for moving a wafer in synchronization with the movement of reticle. A light supply system emits light beams for detecting a relative positional relation between the reticle stage and the wafer stage toward the reticle. On this occasion the emitted light beams are scanned to follow the moving reticle stage, using for example a galvanometer scanner.

Abstract: A method of aligning each of a plurality of processing areas regularly aligned on a substrate according to designed alignment coordinates to a predetermined reference position in a static coordinate system for defining the moving position of the substrate is disclosed. The coordinate positions, on the static coordinate system, of at least three processing areas selected in advance as specific processing areas from the plurality of processing areas are measured. The coordinate positions, on the static coordinate system, of the plurality of processing areas on the substrate are determined by weighting the coordinate positions, on the static coordinate system, of the at least three specific processing areas according to the distances between a processing area of interest and each of the at least three specific processing areas in units of processing areas on the substrate, and executing a statistic calculation using the plurality of weighted coordinate positions.

Abstract: A positioning method involving the following steps is disclosed. Measured are coordinates positions of at least three preselected exposure areas on a static coordinate system among a plurality of exposure areas two-dimensionally formed in accordance with predetermined array coordinates on a photosensitive substrate. Calculative array coordinates of the plurality of exposure areas on the static coordinate system are calculated by using a plurality of first parameters calculated by statistically calculating the plurality of measured coordinate positions. Then, the photosensitive substrate is positioned in an exposure position while being moved in accordance with the calculative array coordinates thus calculated. Specific marks formed on a mask are thus exposed on each of a plurality of predetermined positions on the photosensitive substrate.

Abstract: A scanning exposure apparatus has a mask (reticle) and a photosensitive substrate (a wafer) in an imaging relationship across a projection optical system. A mask stage and a wafer stage are moved simultaneously in first (X) direction with a speed ratio corresponding to the magnification of projection, so that a shot area of the photosensitive substrate is scan-exposed to an original pattern of the mask.The mask is provided, over the scanning range of the original pattern, with mask gratings, each composed of plural grating elements arranged at a predetermined pitch along the first (X) direction. The photosensitive substrate is provided with substrate gratings corresponding to said mask gratings. The positional aberration between said mask gratings and the substrate gratings is detected, through the projection optical system, by positional aberration detecting means.

Abstract: An exposure apparatus includes a projection optical system for projecting a pattern on a mask onto a photosensitive substrate and a measuring unit for measuring distances between the mask and the projection optical system at a plurality of positions within a surface of the mask. The position of the photosensitive substrate with respect to the projection optical system is changed on the basis of a plurality of the distances measured by the measuring unit.

Abstract: A plane positioning apparatus comprises a projector for projecting beams to a given portion on the surface of a substrate in a diagonal direction, a light receiving device to receive beams reflected from the substrate surface and output photoelectric signals in accordance with variation of the light receiving position, a calculating circuit to output deviation signals in accordance with the deviation amount of the substrate surface with respect to a predetermined fiducial plane based on the deviation signals, a substrate shifting device to shift and set the substrate at a given position in a direction perpendicular to the fiducial plane in accordance with the deviation signals, a level variation detecting device to detect level variation of the deviation signals generated when the substrate surface and the fiducial plane are displaced interrelatedly, an inclination calculating device to calculate, in accordance with the level variation characteristics, the value of the inclination of the level variation chara

Abstract: A position detecting method detects each position of a photosensitive substrate when executing shots of circuit patterns so that the circuit patterns are further superposed on the photosensitive substrate already formed with the circuit patterns. The method comprises the steps of performing a shot of a circuit pattern of a reticle in superposition on liquid crystal pixel segments already formed on a glass plate, registering, in a memory, a circuit pattern as a reference image in the liquid crystal pixel segment and performing pattern matching with other fields of the liquid crystal pixel segments by use of this reference image. An alignment is conducted based on a position of circuit pattern extracted thereby.

Abstract: A method and apparatus for measuring relative positional deviation between first and second diffraction gratings formed on an object is disclosed, wherein, in detection of a signal corresponding to the relative positional deviation between the first and second diffraction gratings, a suitable delay is determined in accordance with a signal corresponding to a relative positional deviation between third and fourth diffraction gratings formed on the object and having a predetected relative positional deviation, and wherein the measurement of the positional deviation between the first and second diffraction grating is done on the basis of a signal corresponding to that deviation and of the delay thus determined.

Abstract: A photo-lithography apparatus comprising an effective illumination source, a condenser lens, a reticle, a projection lens, and an XYZ stage, wherein a reduced image of pattern on the reticle is formed on a substrate disposed on the XYZ stage, and wherein the effective illumination source comprises an aperture stop which is mechanically changeable depending on an illumination mode, the apparatus of the invention characterized further comprising: a photo-detector disposed on the XYZ stage for detecting an image of a specific pattern; a drive mechanism for moving the effective illumination source in X, Y, and Z axis-directions; and circuitry for detecting an off-telecentricity amount of the photo-lithography apparatus and outputting adjustment data to the drive mechanism for moving the effective illumination source, wherein the detecting/outputting circuitry is coupled with the photo-detector, the XYZ stage, and the drive mechanism for moving the effective illumination source, thereby misalignment of the effecti

Abstract: An alignment method and system in which substrates having zones, to be aligned and being disposed in a predetermined array, are supplied sequentially and in which in each substrate the zones are brought into alignment with a predetermined reference position sequentially. Deviations in the positions of the zones of a first substrate with respect to positions determined in accordance with the predetermined array, are measured in sequence, and the actual array of the zones through the measurement is detected. The relationship between the predetermined array and the actual array detected in the first step is determined in terms of a predetermined transformation parameter, and a transformation parameter for the first substrate effective to minimize an error, is determined.

Abstract: A method of detecting the positional relationship between a first object and a second object is disclosed which includes projecting a first light through a convex lens mark of the first object and a concave lens pattern of the second object onto a first plane and projecting a second light through a concave lens mark of the first object and a convex lens pattern of the second object onto the first plane, wherein a first spacing between positions of incidence of the first light and the second light on the first plane increases with displacement of the second object relative to the first object in a predetermined direction.

Abstract: An alignment method for aligning each of plural process areas arranged on a substrate to a specified point in a fixed coordinate system defining a position of movement of the substrate, comprises measuring the positions of a number of specified areas, selected in advance from the plural process areas on the substrate; determining plural amounts of deformation between the specified areas and one of the process areas; determining plural weighting coefficients corresponding to the plural amounts of distortion, for each of the specified areas; and calculating the coordinate position of the one of the process areas on the fixed coordinate system, by statistical processing of the measured coordinate positions of the specified areas, utilizing the plural weighting coefficients.

Abstract: Method and device for monitoring a moving web, such as a wire in a paper machine, a felt, or a material web, such as a board or paper web. A bar of radiation beams is directed at the face of the web to be monitored by a series of transmitters in a direction transverse to the direction of movement of the web. Radiation reflected from the web and the background is detected by a series of receivers. The measurement signals obtained in this way are passed to an electronic unit in which a quantity that characterizes the monitoring of the web is determined from the measurement signals. The approximate location of the edge, the edges, or of corresponding discontinuities of the web is detected "digitally" on the basis of the radiation beam of the radiation transmitter in whose area the greatest change takes place in the received radiation.

Abstract: A position detecting apparatus comprises a double-beam producing device for producing two beams different in frequency from each other, which are guided to irradiate a diffraction grating on an object to be inspected in two predetermined directions, and a detector photoelectrically detecting through an objective optical system diffracted light produced by the diffraction grating, in which the double-beam producing device comprises a light source for supplying a beam of a single wavelength or multiple wavelengths, a beam splitting device for splitting the beam from the light source into two predetermined beams, a relay optical system for converging the two split beams at a predetermined position, and a frequency difference producing device disposed at or near a converging position by the relay optical system, for producing a predetermined frequency difference between the two split beams.

Abstract: An apparatus for detecting positions is provided with an auxiliary pattern adjacent to the opaque portion of an index pattern, which has a spatial frequency higher than the insulating spatial frequency of an imaging system in order to obtain a stable signal portion (slope). Using this slope, the positional information of the index pattern is obtained, and on the basis of the positional information, the positions of wafer alignment marks are detected.

Abstract: A position detecting apparatus for optically observing an opaque mark formed on a transparent substrate to detect a position of the mark with a high degree of accuracy. The apparatus includes a detection optical system for forming a detected image of the mark, an illumination system for supplying an illuminating light to the mark through an objective lens of the detection optical system, projection means arranged to face the detection optical system through the substrate and forming a conjugate position to the mark, and reflecting means which is settable substantially at the conjugate position. The image of the mark can be detected as either a bright image or a dark image under the conditions where there are a sufficient contrast between the mark and the background and a uniform background density. The shape of the mark and the arrangement of patterns around the mark can be determined as desired.

Abstract: A method of projection exposure of a shot area on a substrate to a mask pattern by detecting, by a focus detection mechanism, an amount of defocus, in the axial direction of a projection optical system, of a measuring point on the substrate with reference to the focal plane of the projection optical system, then loading the substrate, and moving the substrate to a predetermined height by a Z-stage movable in the axial direction of the projection optical system, based on the value detected by the focus detection mechanism; thereby exposing a shot area of the substrate to the mask pattern.

Abstract: A position detecting apparatus detects a matching state of a position of a surface of a light-transmissive object with respect to a fiducial object plane of an objective optical system. Light transmitted through one-half of a pupil plane of the objective optical system is reflected by a front surface of the object through an opposite half of the pupil plane to a photoelectric detector. Light reflected from a rear surface of the object through the opposite half of the pupil plane is intercepted and prevented from reaching the detector.

Abstract: An image scanning apparatus can obtain, using a simple optical detection system, original sheet information including size and displacement information of an original sheet before an image scanning operation starts. The image scanning apparatus comprises a single beam emitting unit for emitting a coherent first beam. A deflecting unit deflects the first beam so that the first beam traces a predetermined scan line on a plane including a surface of the original sheet. A second beam is generated by reflection of the first beam at the surface of the original, and the second beam is input to the sensing unit via the deflecting unit. The original sheet information is obtained in accordance with the detection of a sharp change in the intensity of the second beam received by the sensing unit with reference to the scanning position of the first beam.

Abstract: The invention described herein is an alignment system used in semiconductor manufacturing. It is the core component used to align a mask containing a circuit pattern to a wafer during a scanning sequence. The alignment system images an alignment reticle pattern onto a wafer which contains alignment marks. During scanning, the light from the alignment reticle image is reflected and scattered by the wafer and its alignment marks. Multiple detectors are placed at a pupil plane of the alignment system to collect the reflected and scattered light in the bright-field and dark-field regions. The resulting signals and their analysis results in determination of accurate alignment of a wafer. The alignment system does not use or "look through" the projection optics of the scanning photolithographic device. The broadband spectrum used for alignment illumination cannot be used in the projection optics designed for the deep UV wavelengths without undesirable results.

Abstract: An attenuated phase-shifting mask has a circuit pattern formed of a layer of halftone phase-shifting material, e.g., SiNx, which inherently appears substantially transparent to the visible light utilized to align the mask with a wafer. The reticle alignment marks of the mask are made of a separate substantially opaque layer in order to ensure that the reticle alignment marks will be visible to the mask/wafer alignment equipment.