Abstract: A position measuring apparatus includes a radiation source mounted on an isolated reference frame and a two-dimensional radiation detector mounted adjacent the radiation source. The object whose position is to be detected has a retro-reflector mounted on it so as to reflect light emitted from the radiation source along a return path that is parallel to but displaced from the incident light path. The amount of displacement is dependent on the position of the object and is measured by the two-dimensional detector. Three such apparatus can be combined in a system to measure the position of the object in all six degrees of freedom.

Abstract: An ultrasonic-welding apparatus including: a cradle, onto which two work pieces are mounted, and which can rotate around an axis vertical to the welding surface of the work pieces; a welding horn, which carries out welding using ultrasonic energy while sandwiching the two work pieces between it and the cradle; a transmission-type laser sensor which measures the fixed part of the work pieces after welding, rotating on the cradle, in the condition that the welding horn is apart from the work pieces after welding; and an optical sensor including a light-emitting part, a light-receiving part, a connecting part on which the light-emitting and light-receiving parts are mounted, and an adjusting part that rotates the connecting part around two axes.

Abstract: A tool is employed in conjunction with alignment, depth, and level detectors. The tool can use all or some of these detectors. The alignment detector provides an orthogonal laser line grid on an incident surface when the detector has a predefined relationship with the surface. The depth detector emits two sets of parallel laser planes that converge with each other. When the laser planes impact on an incident surface two sets of lines are formed. The laser lines from one laser plane set move closer to the lines from the other laser plane set as the depth detector moves closer to the surface—showing changes in depth or distance. The level detector employs two converging laser planes. An operator positions the level detector above an incident surface, so the laser planes' line of intersection appears on the surface if the surface is level. If the surface is not level, lines separate from each laser plane appear on the surface—signaling the need for a level adjustment.

Abstract: The Xray irradiation device 1 issues Xrays to board mark 7 and projects the image of the board mark 7 on the fluorescence screen 3, the fluorescence face 39 of which visibly displays the image of the board mark 7 that can be captured by the CCD camera 2. The CCD camera 2 images the board mark 7 and the mask mark 5 depicted on the photo mask 4 overlapping together. The board 6 and the photo mask 4 are aligned by exposure stage 8 so as to the board mark 7 and the mask mark 5 coincide.

Abstract: A die having at least one opto-electronic device disposed on a front-side of the die has its backside mounted to a submount with the backside positioned to align the front-side opto-electronic devices with respect to the submount. A first set of alignment features are formed on the backside of the die which are aligned to the front-side. The first set of a alignment features is then aligned to a second set of alignment features disposed on the submount and the backside is bounded into place.

Abstract: A material web attribute detection system with the material web having a first side and a second side. The system includes a radiation source located proximate to the first side of the material web and emitting radiation toward the material web, and a radiation detection array located proximate to the second side of the material web and producing a plurality of signals based on the radiation detected from the radiation source. A processor is included which utilizes the plurality of signals to determine a lateral offset and a gap size of the radiation detection array relative to the radiation source. The processor can then compensate for the radiation detection array and radiation source relative misalignment using the plurality of signals, the lateral offset and the gap size.

Abstract: A lithographic apparatus includes a support that provides a magnetic force in a first direction between a first part and a second part of the apparatus. The support comprises first, second and third magnet assemblies, the first and third magnet assemblies attached to the first part and each including at least one magnet oriented such that its magnetic polarization is substantially parallel or anti-parallel to the support direction. The first and third magnet assemblies define a space between them in a second direction that is substantially perpendicular to the first direction. The second magnet assembly is attached to the second part and includes at least one magnet. The second magnet assembly is at least partly located in the space. The at least one magnet of the second magnet assembly has its magnetic polarization oriented so as to produce a bias force substantially along the support direction by magnetic interaction between the first, second and third magnet assemblies.

Abstract: A method for determining an emitting angle of an optical pickup head of an optical drive. A jitter inspection device comprises a jig, simulating and adjusting a tilt angle of the optical pickup head, and a jitter meter installed on the jig, inspecting jitter values at different tilt angles. A quadratic surface equation decreases the data points required for measurement to five, and enables product efficiency to raise 17% , such that the minimum jitter value and optimum tilt angle can be obtained quickly.

Abstract: The invention describes an apparatus for preventing gripping of objects having wrong dimensions or orientation. The apparatus comprises a part handler, e.g., a holder for parts to be treated in a chemical reactor, where the parts has to be transferred from a working position to a temporary storage. The holder may have different shapes, e.g., rectangular, elliptical, or circular, and is provided with positioning openings or recesses for engagement with pins or semispherical elements on the engaging surface of the part handler. The apparatus is provided with at least two through beam optical sensor units with adjustable divergence of the light beams emitted from the light emitting to the light-receiving element. The sensor units are located near the edge area of the holder.

Abstract: A method is disclosed for calibrating a camera used in a scanner for scanning images onto a printed circuit board. The calibration method determines a transformation between the camera and the scanner by writing a pattern on a photosensitized substrate using the scanner, where the pattern is visible without development, and using the camera to image the pattern, from which a transformation between the imager and scanner coordinate systems is determined.

Abstract: A method of device inspection, the method comprising providing an asymmetric marker on a device to be inspected, the form of asymmetry of the marker being dependent upon the parameter to be inspected, directing light at the marker, obtaining a first measurement of the position of the marker via detection of diffracted light of a particular wavelength or diffraction angle, obtaining a second measurement of the position of the marker via detection of diffracted light of a different wavelength or diffraction angle, and comparing the first and second measured positions to determine a shift indicative of the degree of asymmetry of the marker.

Abstract: A method is used for dynamic manipulation and/or for adjustment of a module or a component in an optical system, in particular in a microlithographic projection exposure objective for manufacture of semiconductors. The module or component is displaced by at least two actuators, which have detectors for determining at least their relative path displacements. A position of the module or component is determined by at least two sensors, the sensors and the actuators, with their detectors communicating with one another in the manner of a control loop. At least one impulse is exerted on the module or component by the actuators. The timing of the impulse can be deliberately varied, to which end the displacement of the actuators is carried out with a time-variant velocity profile dictated as a function of a determined position snactual of the module or component. A position snactual of the module or component is re-determined after the velocity profile, has been executed.

Abstract: Alignment-mark patterns are disclosed that are defined on stencil reticles and that can be transferred lithographically from the reticle to a sensitized substrate using charged-particle-beam microlithography. The corresponding alignment marks as transferred to the substrate are detectable at high accuracy using an optical-based alignment-detection device (e.g., an FIA-based device). The transferred alignment marks can be used in place of alignment marks used in optical microlithography systems. An alignment-mark pattern as defined on a stencil reticle includes pattern elements that are split in any of various ways into respective pattern-element portions separated from each other on the membrane of the stencil reticle by “girders” (band-like membrane portions) that prevent the formation of islands in the stencil reticle and that prevent deformation of the pattern elements on the stencil reticle.

Abstract: An optical alignment system for controlling the position of a laser beam through an optical train. The optical alignment system includes a semiconductor laser source for the generation of an alignment beam, and a beam steering device to manipulate the position of the alignment beam on a multi-element detector. The semiconductor laser is driven to mode hop at a frequency greater than the upper frequency limit of the multi-element detector. Driving the semiconductor laser to mode hop at a frequency greater than the upper frequency limit of the multi-element detector results in a more uniform alignment beam as seen by the detector, as the alignment beam becomes an average of all the operational modes of the semiconductor laser. A more uniform alignment beam results in improved accuracy of the alignment system.

Abstract: Embodiments of the invention generally provide an in situ method for assembling and measuring optical characteristics of an optical component. The method generally includes pressing an optical source or lens into an optical housing while simultaneously measuring the optical output of the device. The measured optical output is used to determine and control when the optical source or lens is pressed to an optical position within optical housing. Once the source or lens is pressed into the optical housing, the method includes measuring the optical offset and/or pointing angle of the assembled component in the same apparatus that assembled the component. The measured optical offset and/or pointing angle information is used to determine how to mechanically alter the optical housing to correct or compensate for the optical offset and pointing angle.

Abstract: An exposure method is provided so that the dividend regions defined on a wafer are successively exposed using pulses of laser light emitted from an excimer laser light source in such a way that each region receives a different level of target exposure levels. And, transmittance of a course energy adjuster, having a number of neutral density filters, is adjusted so that a sub-divided region receiving the least number of exposure pulses can receive a pulse count that exceeds the minimum number of exposure pulses required for optimal exposure. During the process of scanning exposure, transmittance of the coarse energy adjuster is held constant so that, to compensate for variations in the pulse energy, the output power of the excimer laser light source is adjusted according to real-time data output from an integrator sensor.

Abstract: Two pieces of semiconductor wafers 101 and 102 to be stacked and fused together are secured to wafer holders 201 and 202 respectively, and are then integrally held at a wafer hold unit 2. Rough position alignment is first applied to these semiconductor wafers 101 and 102 while supplying infrared light thereto from an infrared light source 30 of an infrared light system 3 for detection of a resultant lattice image at a detection unit 5. Then, fine position alignment is performed while supplying laser light from an laser light source 40 of a laser light system 4 for detection of a resultant diffraction image at the detection unit 5.

Abstract: A position measuring system that includes a graduation support having a first detent and a detector arrangement on a holder for scanning the graduation support at a preset scanning distance. An adjusting device that sets the preset scanning distance, the adjusting device is displaceable relative to the holder along a first direction from a mounting position to an operating position. The adjusting device includes a second detent which, in the mounting position, acts together with the first detent of said graduation support acting in the first direction, and the first and second detents are out of engagement at the operating position and a receiver which, at the mounting position, maintains the graduation support oriented perpendicularly with respect to the first direction, and the receiver is removed from the graduation support by being displaced in the first direction.

Abstract: An optical alignment system for controlling the position of a laser beam through an optical train. The optical alignment system includes a semiconductor laser source for the generation of an alignment beam, and a beam steering device to manipulate the position of the alignment beam on a multi-element detector. The semiconductor laser is driven to mode hop at a frequency greater than the upper frequency limit of the multi-element detector. Driving the semiconductor laser to mode hop at a frequency greater than the upper frequency limit of the multi-element detector results in a more uniform alignment beam as seen by the detector, as the alignment beam becomes an average of all the operational modes of the semiconductor laser. A more uniform alignment beam results in improved accuracy of the alignment system.

Abstract: The invention is directed to an ultrasonic testing system. The system tests a manufactured part for various physical attributes, including specific flaws, defects, or composition of materials. The part can be housed in a gantry system that holds the part stable. An energy generator illuminates the part within energy and the part emanates energy from that illumination. Based on the emanations from the part, the system can determined precisely where the part is in free space. The energy illumination device and the receptor have a predetermined relationship in free space. This means the location of the illumination mechanism and the reception mechanism is known. Additionally, the coordinates of the actual testing device also have a predetermined relationship to the illumination device, the reception device, or both.

Abstract: A device for assembly of components, in particular semiconductor chips, on a substrate having a first traversing unit for picking up the component together with a component holder at a first location and setting down the component at a second location on the substrate is described, a position measuring unit for optically determining an actual position of the component as a function of an actual position of the substrate being situated on an optical traversing unit for traversing the position measuring unit from a working position in the area of the substrate to a resting position; this permits fully automatic assembly of a wide variety of components on substrates and at the same time has a high throughput in interlinked production and a very high positioning precision. This is achieved by the fact that the substrate is situated on a conveyance device for largely continuous supply and removal of numerous substrates to and from the device.

Abstract: A notch or flat sensor for a semiconductor wafer on a wafer stage or support includes a dual photodiode detector arrangement located at the edge position of the wafer. Each photodiode element has substantially equal coverage of the wafer edge when the wafer's notch or flat is not proximate to the detector, but has different coverage from the other photodiode when the notch or flat is proximate to the detector. A light source illuminates the edge of the wafer opposite the detector arrangement. Comparison of the light intensity sensed by each photodiode, e.g. by means of a differential amplifier circuit and threshold sensor, reveals the position of the notch or flat.

Abstract: The present invention provides a method and apparatus for high-speed autofocus and tilt of an inspection surface in a microscope system. The method and apparatus herein described projects an array of spots, lines, circles, grids or other shapes on the surface to be adjusted. The superposition of the array on the surface is imaged by a CCD camera and captured for subsequent analysis. Analysis of the captured image determines both the distance and angle through which the surface must be adjusted to bring it into the focal plane of the optical system. Focus and tilt error is estimated by comparing image dilation and distortion with calibrated data.

Abstract: The present invention provides a laser sighting device, which comprises a tilt detecting device having a liquid member for forming a free liquid surface and a fixed reflection member fixedly mounted, the tilt detecting device being used for detecting angular deviation between the free liquid surface and the fixed reflection member, a main unit for accommodating the tilt detecting device, and a laser beam irradiation unit removably mounted on the main unit.

Abstract: A magnetic head positioning apparatus for adjusting the position of a head member relative to its support member by determining the boundary lines for the edge portion of the head body and the center of the pivot in the support member. Luminance variations near the boundary line between areas different in light reflections are derivated so as to determine the position of the boundary line with a high accuracy at a distance shorter than the unit block pitch of the camera photodetectors used to detect the image of the head body and the support member.

Abstract: An apparatus for sensing mis-alignment between an aircraft inertial reference frame and a reference frame of an attached sensor is disclosed. The apparatus includes a first laser mounted on the sensor and in the center of and normal to a first measuring surface; and, a second laser also mounted on the sensor perpendicular to the first laser and in the center of and normal to a second measuring surface. A first reflector is mounted to and aligned with the inertial reference frame of the aircraft and is disposed for reflecting a beam of light from the first laser, whereby misalignment in roll and yaw between the sensor and the aircraft is reflected on the first measuring surface.

Abstract: A tilt detecting device for detecting tilt by a reflection light from a free liquid surface, comprising a photodetection element, a liquid member for forming the free liquid surface, a fixed reflection member fixed on a structural member, a free liquid surface light projecting system for projecting a light toward the liquid member, a fixed reflection member light projecting system for projecting a light toward the fixed reflection member, a photodetection optical system for guiding the reflection light from the free liquid surface of the liquid member and a reflection light from the fixed reflection member toward the photodetection element, and an arithmetic processing unit for calculating deviation based on two reflection images received by the photodetection element.

Abstract: An apparatus for exposing a light sensitive surface (e.g., a printed circuit board) to light. An optical processor subsystem, which includes a reflector and an integrator-collimator assembly, processes light from a light source to produce a uniform and collimated light beam having a mean angle of incidence relative to the light sensitive surface of less than or equal to 2° and having illumination uniformity that departs by less than ±10% from a mean value. An optical light shaper subsystem transforms the uniform and collimated light beam into a uniform and collimated light strip. A displacement mechanism provides relative movement between the light strip and the light sensitive surface. A speed matching mechanism matches the speed of relative displacement to the brightness of the light strip and to the sensitivity of the light sensitive surface. The light source remains stationary in one construction and moves relative to the light sensitive panel in another construction.

Abstract: An alignment system and method is disclosed, the alignment system and method provide for alignment of at least one component to an optical signal using a neural controller circuit. The neural controller circuit facilitates parallel and sequential alignment of a plurality of components to the optical signal.

Abstract: A method and apparatus reduces undesirable glints in an optical position alignment sensor designed to orient components. Collimated light is provided onto the component. A filter is positioned behind the components and is used to block glint generated by the components. The filter is tunable by rotating it about an axis in the plane of the component.

Abstract: A method of detecting focus information about an image projecting optical system includes performing mark projection through the optical system, and, based on illumination lights having different chief ray incidence directions, the mark projection is carried out so that mark images formed by the illumination lights, respectively, are superposed one upon another approximately upon an imaging plane, and detecting focus information about the optical system on the basis of information related to a deviation between the mark images superposed.

Abstract: A device for detecting register marks includes at least one receiver for scanning register marks along a track disposed in a direction of movement of the register marks, and a device for positioning the receiver transversely with respect to the track, in order to determine an offset of the receiver with respect to the track, at least one positioning mark being disposed upline of the register marks in the direction of movement thereof, the positioning mark having at least one edge extending at an angle to the track, having an extent transverse to the track, which is a multiple of the extent of the register marks, and having a predetermined positional relationship to the track which is transverse to the track.

Abstract: An optical sensor for detecting the presence or absence of sheet products in a moveable device has a fixed light source, a fixed light detector spaced from the fixed light source, and a light transfer device fixedly connected to the moveable device for directing light from the fixed light source to the light detector as the moveable device passes by the fixed light source. Also disclosed is a device for transferring and moving sheet products and a method for detecting sheet products by an optical sensor having the steps of inserting a first sheet product into a first moveable device, aligning the first moveable device with a fixed light source and a fixed light detector, and transmitting light from the fixed light source across an opening of the first moveable device.

Abstract: In an image recording apparatus which records an image on a recording medium by moving (subscanning) the recording medium while the recording medium is scanned (main scanning) with a scanner, a feed amount of the photosensitive material is detected by a detector and, on the basis of the detected result, a variation amount of movement speed is computed at a controller. A motor, which drives a light source unit in a main scanning direction is adjusted in accordance with the variation amount. Thus, a subscanning direction scanning line pitch error is corrected.

Abstract: To provide a package structure for securing a satisfactory optical coupling between an optical device arranged beforehand on a printed board and an optical device newly mounted on the particular printed board. Positioning LDs 41a and 41b are arranged on a printed board 1. A sensing PD 42a for receiving the optical signal emitted from the positioning LD 41a and a sensing PD 42b for receiving the optical signal emitted from the positioning LD 41b are arranged in an OEIC package 11 mounted on the printed board.

Abstract: A mark position detecting system includes a light source for illuminating light on a mark for alignment measurement formed on a semiconductor substrate, a light detecting optical system and a measured light intensity profile preparing part, a theoretical light intensity profile preparing part, a light intensity profile comparison part. The measured light intensity profile preparation part prepares a measured light intensity profile denoting light intensity of reflected light from the mark from a detection result by the detecting optical system. The theoretical light intensity profile preparing part prepares a theoretical light intensity profile of the reflected light from a region of the mark where the intensity would change, using information on the shape and material of the mark. The light intensity profile comparison part compares the theoretical light intensity profile with the measured light intensity profile to detect the mark and misalignment.

Abstract: A surface position detecting method wherein an object having a region with a pattern structure formed thereon is relatively scanned relative to a surface position detecting device and surface positions of the object at plural detection points in the region are detected by use of the surface position detecting device.

Abstract: Mounting and alignment structures for optical components allow optical components to be connected to an optical bench and then subsequently aligned, i.e., either passively or actively, in a manufacturing or subsequent calibration or recalibration, alignment or realignment processes. The structures comprise quasi-extrusion portions. This portion is “quasi-extrusion” in the sense that it has a substantially constant cross section in a z-axis direction as would be yielded in an extrusion manufacturing process. The structures further comprise at least one base, having a laterally-extending base surface, and an optical component interface. At least one armature connects the optical component interface with the base. In the preferred embodiment, the base surface is securable to an optical bench.

Abstract: A method and apparatus determines the position P of a structural element that is non-orthogonal relative to the coordinate axes (x, y) of a substrate. The structural element is imaged on a detector array of a CCD camera that has a reference point. With the aid of a measuring window that is rotated at an angle &thgr; to the substrate coordinate system, the position PIPC of one edge of the structural element is determined relative to the reference point. The position L of the reference point relative to the origin of the substrate coordinate system is determined from the angle &THgr; and the current measuring stage coordinates, so that for a particular position P, P=PIPC+L, where L=x·cos &thgr;y·sin &thgr;.

Abstract: The invention provides a face position detection method and a face position detection apparatus which can perform detection of the face position of a substrate with high precision, even when a pattern having a large stepped portion is formed by means of a plurality of layers on the surface of the substrate, and an exposure method and an exposure apparatus. Measurement beams S1 to S9 are irradiated onto a plurality of places on the surface of a substrate (object) W using a beam irradiation system (irradiation system) 4, the plurality of measurement beams S1 to S9 from the surface of the substrate W are then detected using a beam reception system (detection system) 5, and face positional information for the surface of the substrate W is obtained based on the detection results for the plurality of measurement beams S1 to S9 using a signal processing unit 41.

Abstract: An apparatus and a method for aligning a loadport on a process machine are disclosed. The apparatus is constructed by a base plate, an alignment block mounted on the base plate, a light source and an optical detector. The alignment block is provided with an aperture extending longitudinally through the block, or formed in a T-shape extending both longitudinally and transversely through the block. The light source may be suitably a laser emission source, or a laser source that operates in a pulse mode. The diameter of the aperture provided in the alignment block should be sufficiently small, i.e. smaller than 5 mm, and preferably smaller than 3 mm.

Abstract: In a method for determining alignment of line formations of a web, a radiation source emitting radiation and a detector with numerous radiation sensors for sensing the radiation are provided. The radiation source and the detector are reciprocated together simultaneously transversely across the web. During reciprocation across the web, at least one measuring location of the web is irradiated by the radiation source and measured values, based on local radiation intensities are measured by the radiation sensors of the detector. The measured values are communicated to a computer. The computer generates, based on the measured values and the relative positions of the radiation sensors to one another, a local structural image of the at least one measuring location of the web.

Abstract: A position detecting method and a position detecting device which make it possible to detect with high accuracy by an image processing method the relative positions of two objects spaced apart in the optical axis direction of a detection optical system, and a semiconductor device manufacturing method using the position detecting method and the position detecting device. In detecting the relative positions of a first object (e.g., a mask) and a second object (e.g., a wafer), there is provided a third object equipped with separate reference alignment marks, and optical images of the reference alignment marks on the third object and optical images of the position detecting marks on the first and second objects are detected by an image pickup device, thereby detecting positional deviation between the first and second objects.

Abstract: Reticles and reticle-evaluation methods are provided that allow charged-particle-beam (CPB) reticles to be evaluated quickly and accurately. The reticles include one or more device-pattern regions. Alignment-pattern regions are arranged in respective rows along the “upper” and “lower” edges of the device-pattern region(s). Each device-pattern region includes multiple subfields into which a device pattern is divided and defined. Also flanking each device-pattern region are respective evaluation-pattern regions situated along the “left” and “right” edges of the device-pattern region(s). Each evaluation-pattern region includes multiple small membrane regions each having a respective subfield that defines a respective evaluation pattern. The evaluation pattern includes various lines having respective widths, positions, and shapes that are measured and evaluated.

Abstract: A device for precision measurement of shafts, spindles, or the like calls for two surfaces which are combined with one another, of which one is partially reflecting and the other is roughly fully reflecting. These surfaces reflect an incident light beam independently of one another onto a single optoelectronic target. The target can be read out two-dimensionally and is pixel-oriented. From only a single measurement position, the azimuth and elevation, and the parallel offset between the incident light beam and a center of the reflecting surfaces can be determined.

Abstract: Method and device for the passive alignment of optic fibers and components, using slots.

Abstract: A method and of determining scanner coordinates to accurately position a focused laser beam. The focused laser beam is scanned over a region of interest (e.g. an aperture) on a work-surface by a laser scanner. The position of the focused laser beam is detected by a photodetector either at predetermined intervals of time or space or as the focused laser beam appears through an aperture in the work surface. The detected position of the focused laser beam is used to generate scanner position versus beam position data based on the position of the laser scanner at the time the focused laser beam is detected. The scanner position versus beam position data can be used to determine the center of the aperture or the scanner position coordinates that correspond with a desired position of the focused laser beam.

Abstract: Within each of: (1) a method for inspecting a reticle; (2) an apparatus for inspecting the reticle; and (3) a method for forming a microelectronic layer while employing the method for inspecting the reticle and the apparatus for inspecting the reticle, there is employed a pair of wedges whose inclined surfaces are counter-opposed and separated by a gap. The pair of wedges whose inclined surfaces are counter-opposed and separated by the gap is employed in conjunction with an inspection light source and detector for determining an optimizing an optical characteristic of the reticle, such as an optimized optical interference characteristic of the reticle, such that the reticle may be optimally aligned within a photoexposure apparatus and there may be formed with optimal registration while employing the reticle and the photoexposure apparatus a microelectronic layer within a microelectronic fabrication.

Abstract: A method and apparatus are provided for fast and thorough inspection of tray stacks for misplaced ICs that is not susceptible to human error and prevents shipment of damaged ICs to users. Embodiments include an inspection apparatus, such as at a conventional strapping machine, comprising a number of photoelectric sensors near the corners of the trays of the stack. The sensors are moved, as by pneumatic cylinders, such that each sensor scans all of the trays in the stack, one tray at a time, while directing a beam of light at the tray and receiving a quantity of the light of the beam reflected from the stack. The received quantity of light is compared to an expected reference quantity of light corresponding to a tray without any misplaced ICs, and a signal is generated and sent to a processor based on this comparison.

Abstract: An illumination device emits detection light toward the surface of a substrate from an oblique direction with respect to the substrate. The detection light is shaped into a slit beam by an optical shaper. An alteration device changes the width of the slit beam by controlling the optical shaper. The slit beam strikes the surface of the substrate through an optical element. The slit beam reflected from the surface of the substrate is oscillated along the width direction of the slit by a controlled oscillation mirror. A detector detects the surface height of the substrate based on the oscillating slit beam.