Abstract: The interferometric alignment device is a small, compact device that can be attached to any two optical instruments that need to be aligned precisely in both pitch and yaw angles. The device utilizes light reflecting from mirrors that are permanently mounted inside the instruments, one mirror in each of the instruments. The reflected light beams exit their respective instruments via a window built into the frame of the instrument and re-enters the attached alignment device wherein they combine to form an interference pattern. The operator of the alignment device observes the fringes of this pattern and adjusts the azimuth and elevation of one instrument relative to the other instrument until the fringes are at an acceptable minimum number or are eliminated altogether.

Abstract: An apparatus for measuring rectilinear motion and rotation angle errors of a rectilinearly moving body having a horizontal, parallel two-surface mirror positioned in a horizontal plane and including two reflection mirrors whose reflection surfaces face each other and are spaced by a distance (2)d and a vertical, parallel two-surface mirror positioned in a vertical plane and including two reflection mirrors whose reflection surfaces face each other and are spaced by a distance (2)d, and also has a light source for generating a laser beam, semi-transparent mirrors for splitting the laser beam into two laser beams, optical path changing reflection mirrors for changing a direction of each laser beam, and position sensors for detecting positions of the laser beam reflected from the horizontal, parallel two-surface mirror and the vertical, parallel two-surface mirror, respectively fixed to positions outside of the rectilinearly moving body.

Abstract: A position detecting method and position detecting system, for measuring a position of a pattern formed on an object to be observed, for use in an exposure apparatus. The method includes providing incoherence-transformed illumination light for illuminating the pattern surface of the object by use of coherent light, and incoherence-transformed reference light, changing the quantity of the reference light in accordance with a reflection factor of the pattern surface, imaging reflection light from the pattern surface and reference light reflected by a conjugate mirror, together, upon a photoelectric converting element, and measuring the position of the pattern on the basis of an interference image signal obtainable by the imaging.

Abstract: An electronic template delineating distinct selected patterns corresponding to predetermined regions of interest in a sample part is used to limit analysis to those regions. The surface of the sample is first measured using conventional techniques. The data so acquired are used to identify boundaries between distinct regions, which are then compared to a predetermined pattern boundary in the template to find a best-fit match. The position of the pattern is then shifted to overlay the match, thereby automatically aligning the template's selected patterns with the regions of interest in the sample surface. As a result, profilometric analysis can be limited to the regions of interest. Correction factors are also assigned to each selected pattern in the template to account for physical differences in the corresponding regions of interest of the sample part that affect the profilometric measurement.

Abstract: A method, system, and storage medium for determining retide tilt in a lithographic system is provided. Test patterns contained on a reticle are printed in a photoresist located on an upper surface of a semiconductor substrate by a lithographic system. The test patterns may include three posts of different diameters wherein one of the diameters is approximately equal to the minimum allowable feature size printable by the lithographic system. Images of the test patterns are measured by a scanning electron microscope under the control of a computer system. The computer system then assesses the measured images of the test patterns to determine if the reticle tilt is acceptable or unacceptable. In one embodiment, the computer system may assess the measured images by comparing the measured images to predetermined images of the test patterns for different focus conditions. The computer system may also calculate the amount of reticle tilt.

Abstract: An electronic template representing the topography of a magnetic head being tested and delineating distinct patterns corresponding to particular regions of interest, such as ABS surfaces, is provided in order to limit analysis of the sample's surface to such regions. The outline of the slider positioned within the field of view of an interferometric microscope is identified by measuring the modulation of incident light at each pixel inside and outside the contour of the sample using the loci of perceivable fringe contrast as the criterion for establishing the location of such edges. Once the outline of the slider within the plastic tray is so established, the slider is shifted within the field of view to match the position of the template, thereby automatically achieving a precise alignment of the template with the boundary of the slider.

Abstract: The interferometric alignment device is a small, compact device that can be attached to any two optical instruments that need to be aligned precisely in both pitch and yaw angles. The device utilizes light reflecting from mirrors that are permanently mounted inside the instruments, one mirror in each of the instruments. The reflected light beams exit their respective instruments via a window built into the frame of the instrument and re-enters the attached alignment device wherein they combine to form an interference pattern. The operator of the alignment device observes the fringes of this pattern and adjusts the azimuth and elevation of one instrument relative to the other instrument until the fringes are at an acceptable minimum number or are eliminated altogether.

Abstract: In a method of measuring, in a lithographic manufacturing process using a lithographic projection apparatus, overlay between a resist layer (RL), in which a mask pattern (C) is to be imaged, and a substrate (W), use is made of an alignment-measuring device (AS1, AS2) forming part of the apparatus and of specific overlay marks (P10, P11) in the substrate and resist layer. These marks have periodic structures with periods (PE10, PE11) which cannot be resolved by the alignment device, but generate an interference pattern (Pb) having a period (PEb) corresponding to the period of a reference mark (M1; M2) of the alignment device.

Abstract: For determining the alignment of a substrate (W) with respect to a mask (MA), a substrate alignment mark (P10), having a periodic structure, and an additional alignment mark (P11), having a periodic structure and provided in a resist layer (RL) on top of the substrate, are used. Upon illumination of these two marks, having a period (PE10; PE11) which is considerably smaller than that of a reference mark (M1; M2), an interference pattern (Pb) is generated, which has a period (PEb) corresponding to that of the reference mark. By measuring the movement of the interference pattern with respect to the reference mark, the much smaller mutual movement of the fine alignment marks can be measured. In this way, the resolution and accuracy of a conventional alignment device can be increased considerably.

Abstract: An optical probe apparatus for determining a position of an image sensor in a digital camera relative to a reference surface on the digital camera. The optical probe assembly includes a probe mounting surface adapted to be removably mountable to the digital camera and lockable in a predetermined orientation relative to the reference surface of the digital camera; an angle cleaved optical fiber emitting a beam of light; a lens disposed in the path of the beam of light and directing the beam of light along an axis normal to a plane of the lens toward the object; and a mounting member supporting the optical fiber such that the beam of light is directed along an axis normal to the plane of the lens and directed to the center of the lens. An optically transparent material (such as a pellicle or glass plate) is disposed intermediate the probe mounting surface and image sensor.

Abstract: A stage apparatus on which a laser interferometer is mounted includes a reticle stage (1) movable in three, X-, Y-, and &thgr;-axes, laser heads (8a-8d) each for generating a laser beam, interferometers (9a-9d) each of which is mounted on the stage (1) and splits the laser beam into reference and measurement beams, bar mirrors (11a-11c) each of which is arranged outside the stage (1) and reflects the measurement beam, and detectors (10a-10c) each for detecting the interference beam of the reference and measurement beams.

Abstract: The present invention provides a method and apparatus for measuring both the linear displacement and angular displacement of an object using a linear interferometer system and an optical target comprising a lens, a reflective surface and a retroreflector. The lens, reflecting surface and retroreflector are specifically aligned and fixed in optical connection with one another, creating a single optical target which moves as a unit that provides multi-axis displacement information for the object with which it is associated. This displacement information is useful in many applications including machine tool control systems and laser tracker systems, among others.

Abstract: A position detecting system to be used with a grating mark provided on an object and having different directionalities is disclosed, wherein light is projected to the grating mark, and wherein light from the grating mark is detected through a beam splitter disposed at or adjacent a pupil of a detection optical system, for receiving light from the grating mark, the beam splitter having a reflective coating partially formed thereon.

Abstract: An exposure apparatus includes a projection optical system, a barrel supporting member for supporting the projection optical system, a stage being movable relative to the projection optical system, a base for supporting the stage, a base measuring system for measuring at least one of a position and a displacement of the base with respect to the barrel supporting member, and a stage measuring system for measuring at least one of a position and a displacement of the stage with respect to the barrel supporting member.

Abstract: The invention features an interferometry system which includes at least one dynamic beam steering assembly for redirecting one or more beams within the interferometry system in response to changes in the angular orientation or position of the measurement object. A control circuit controls the beam steering assembly based on a signal derived from one or more beams within the interferometry system. For example, the control circuit can cause the beam steering assembly to redirect a measurement beam within the system such that exit measurement and reference beams used to generate an interferometric signal remain substantially parallel to one another over a range of angular orientations or translations of the measurement object. The interferometry systems can be advantageously incorporated into lithography systems used to fabricate integrated circuits and other semiconducting devices and beam writing systems used to fabricate lithography masks.

Abstract: Interferometric methods are presented to facilitate alignment of image-plane components within an interferometer and for the magnified viewing of interferometer masks in situ. Fourier-transforms are performed on intensity patterns that are detected with the interferometer and are used to calculate pseudo-images of the electric field in the image plane of the test optic where the critical alignment of various components is being performed. Fine alignment is aided by the introduction and optimization of a global contrast parameter that is easily calculated from the Fourier-transform.

Abstract: An exposure apparatus includes a projection optical system, a barrel supporting member for supporting the projection optical system, a stage being movable relative to the projection optical system, a base for supporting the stage, a base measuring system for measuring at least one of a position and a displacement of the base with respect to the barrel supporting member, and a stage measuring system for measuring at least one of a position and a displacement of the stage with respect to the barrel supporting member.

Abstract: A laser beam or other parallel light beam divides at a beamsplitter into sample and reference beams. The sample beam reflects from a reflective surface back to the beamsplitter, and the reference beam reflects from a retroreflector back to the beamsplitter. The beams are then directed into a telescope. The angle between sample and reference beams at the telescope is proportional to the angle between the laser beam and the normal to the reflective surface. The telescope collects both sample beam and reference beam and transforms each beam into a sharply defined point image. The lateral separation between the two point images is proportional to the magnification of the telescope and to the angle formed at the telescope between the sample beam and the reference beam. If the reflective surface is accurately aligned relative to the laser beam, then the two point images are substantially superposed on one another.

Abstract: An interferometric lithographic apparatus includes an arrangement for applying interfering laser beams to a part for producing a first interference pattern. The first interference pattern has a first fringe spacing. A mobile part holder stage is repositioned to change the interference pattern and produce a second fringe spacing. A control arrangement, automatically responsive to the repositioning of the part holder, re-aligns optical paths and optimally interferes the laser beams to produce the second fringe spacing.

Abstract: A projection exposure apparatus and method aligns a substrate with an optical axis of a lens column using one or more interferometers, mirrors, and a control device. The lens column projects a pattern from a mask onto the substrate. The optical axis of the lens column is perpendicular to the substrate. To ensure precise alignment of the lens column and the substrate, the one or more interferometers use a plurality of beams having respective paths, the lengths of which change in response to movement of the optical axis. In response to the detected changes of the interferometer beams, a control device adjusts the position of the stage so that the substrate is aligned with the optical axis of the lens column.

Abstract: A distance measurement apparatus for measuring distance to the target by measuring a time elapsed from the emission of pulsed light to the target until the receiving thereof. This apparatus comprising a light-emitting section, a light-receiving section, a delay circuit for delaying at least one of generation of the trigger signal with respect to a measurement start signal and the outputting of the measurement stop signal with respect to the reflected pulsed light and outputting thus delayed signal, a reference clock section, time measuring sections consisting of a start-side and stop-side fractional time signal measurement sections and a counter section, and a distance measurement section for determining, based thus measured items, the distance to the target according to the time from the emission of the pulsed light to the receiving thereof.

Abstract: A speed and/or position determining device for determining the speed or position of a target object includes a head-up display for simultaneously viewing both the target object and an image of information regarding the target object. An optical projection system for projecting the information image from a light emitting display to a combining sight of the head-up display passes along a short straight optical axis between the light emitting display and the combining sight. The device may also incorporate a novel method for determining the length of a time period that elapses between the time that a radiation emitter emits a pulse of radiation and the time a reflected portion of the emitted pulse of radiation is received back at the device. The novel method makes use of one or more electronic delay modules having a plurality of tap lines. An electronic state of each of the tap lines changes as a signal input to the delay module propagates through the delay module.

Abstract: A method and system for deriving a travel distance of an object which travels. As one aspect, a travel velocity of the object producing a pulse signal in response to travel of the object on the basis of a number of pulses of the pulse signal per unit time is calculated, and a plurality of unit travel distances corresponding to a plurality of travel states of the object every travel state are calculated. The plurality of travel states are different from each other and the unit travel distance is a travel distance per pulse calculated by dividing the calculated travel velocity by the number of the pulses of the pulse signal per unit time. And the plurality of calculated unit travel distances are memorized individually, from the plurality of memorized unit travel distances, the unit travel distance corresponding to the travel state of the object which is under travel is selected, and the travel distance of the object on the basis of the selected unit travel distance and the pulse signal is derived.

Abstract: The present invention is directed to a method and apparatus for detecting reflected pulses from multiple targets in a field of view such that range to each target can be detected with high resolution, even when the targets are located over a relatively wide measurement range. Exemplary embodiments of the present invention can provide real-time acquisition of ranging data, and can be implemented in a practical cost-effective manner suitable for reconfiguration.

Abstract: Disclosed herein is a distance measuring apparatus comprising an irradiation unit for generating an electromagnetic wave, a receiving unit for receiving a reflected wave of the electromagnetic wave reflected by an object of measurement and generating a reception signal, and a propagation delay time measuring unit for measuring a propagation delay time by counting the number of pulses of a pulse train having a predetermined frequency. The propagation delay time is the time between the time that the irradiation unit irradiates the electromagnetic wave and the time that the reflected wave is received by the receiving unit.

Abstract: A "laser tape measure" for measuring distance which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays.

Abstract: An exclusively digital timing engine that measures extremely short time intervals for use in time of flight systems such as laser range finding systems. This exclusively digital timing engine minimizes the use of high speed, high cost components by employing a novel time multiplexing scheme to execute each of the primary time of flight functions: frequency synthesis, range gating, and time of flight interval measurement. In addition, the timing engine incorporates a random time delay scheme which enhances the resolution of the time interval measurement.

Abstract: In a light-wave distance meter based on light pulses, a light pulse radiation device radiates light pulses emitted by a light source device to a target of measurement, a light reception device receives reflected light pulses from the target, a sampling device samples reception signals, a timing device applies a dither of a certain range to the light pulse emission timing and sampling timing, a cumulative memory device stores sampled signals at a certain interval cumulatively, and a computation device calculates the distance to the target. The distance meter is capable of measuring the position of received light pulses at a resolution higher than the sampling timing.

Abstract: A power management system for a laser range finder including a microcontroller which controls the supply of power by a series of linear regulators to analog electronics and digital electronics such that the respective electronics units are powered only during intervals when they require power during operation of the laser range finder. The linear regulators and a laser firing pulse generator circuit are powered by simplified DC/DC converter circuitry which is, in turn, supplied with power by a solid state front end circuit subject to control by the microcontroller and which includes first, second, and third transistors providing reverse voltage protection, overvoltage protection, and reduced power consumption.

Abstract: An apparatus and a method for measuring a distance optically using a phase variation. The apparatus comprises a light emitting circuit for emitting a high-power intermittent pulse light beam to an object, a light receiving circuit for receiving a light beam reflected from the object, a signal generation/phase difference detection circuit for generating first and second pseudo intermittent pulse signals in response to a drive signal from the light emitting circuit and an output signal from the light receiving circuit, respectively, detecting a phase difference between the generated first and second pseudo intermittent pulse signals and measuring a phase-delayed time on the basis of the detected phase difference, and a controller for performing a control operation in response to an output signal from the signal generation/phase difference detection circuit.