Abstract: A step-and-repeat alignment and exposure system is provided with an adjustable holder for holding a main reticle, a main optical unit including a projection lens for producing an image of the main reticle at an image plane, a stage movable along coordinate axes adjacent to the image plane, and a holder rotatably mounted on the stage for holding a semiconductive wafer to be aligned with respect to the image of the main reticle. The system is further provided with an adjustable holder for holding an auxiliary reticle, a single channel auxiliary optical unit including a main objective lens for producing an image of the auxiliary reticle at the image plane, and a reference mark disposed on the stage and aligned with respect to the coordinate axes.

Abstract: An alignment and exposure system is provided with a main stage movable along orthogonal axes to position either a reference mark, aligned with one of those axes, or a semiconductive wafer directly beneath a projection lens. Another stage is disposed above the projection lens to position a reticle, selectively illuminated by a light source unit, with respect to the reference mark. The light source unit includes a lamp for directing illumination and exposure light along an optical path extending through the reticle and projection lens, a pair of filters for selectively controlling whether illumination or exposure light passes along that optical path to the reticle, a pair of shutters for selectively controlling passage of the selected light along that optical path to the reticle, and a plurality of different mask plates for selectively controlling the portions of the reticle illuminated by the selected light when one of the shutters is opened.

Abstract: An optical focusing system is provided for accurately focusing a wafer surface, thereby enabling the production of sharp microcircuit images. Accurate focusing is achieved despite non-parallel and non-flat wafer surfaces, despite differences in reflectivity of different portions of the wafer surface, and despite changes in environmental conditions such as temperature during system operation.The system comprises a full aperture focus detection apparatus, a kinematic lens positioning apparatus, and a kinematic wafer chuck differential leveling or positioning apparatus. The full aperture focus detection apparatus detects the extent to which a wafer surface is out of focus with respect to the image plane of a projection lens, and produces an amplified differential signal having magnitude and polarity indicative of the extent and direction, relative to the image plane, that the wafer surface is out of focus.

Abstract: A gas bearing is provided which has a spherically contoured pocket with a gas supply passage which opens in the center of the pocket. The gas bearing is coupled to the load and is supported by a stem and a ball joint through which the gas is supplied to the bearing. An additional passage allows gas to flow between the pocket and a closed chamber in the bearing.

Abstract: An alignment and exposure system is provided with a main stage movable along orthogonal axes to position either a reference mark, aligned with one of those axes, or a semiconductive wafer directly beneath a projection lens. Another stage is disposed above the projection lens to position a reticle, selectively illuminated by a light source unit, with respect to the reference mark. The light source unit includes a lamp for directing illumination and exposure light along an optical path extending through the reticle and projection lens, a pair of filters for selectively controlling whether illumination or exposure light passes along that optical path to the reticle, a pair of shutters for selectively controlling passage of the selected light along that optical path to the reticle, and a plurality of different mask plates for selectively controlling the portions of the reticle illuminated by the selected light when one of the shutters is opened.

Abstract: A step-and-repeat alignment and exposure system is provided with an adjustable holder for holding a main reticle, a main optical unit including a projection lens for producing an image of the main reticle at an image plane, a stage movable along coordinate axes adjacent to the image plane, and a holder rotatably mounted on the stage for holding a semiconductive wafer to be aligned with respect to the image of the main reticle. The system is further provided with an adjustable holder for holding an auxiliary reticle, a single channel auxiliary optical unit including a main objective lens for producing an image of the auxiliary reticle at the image plane, and a reference mark disposed on the stage and aligned with respect to the coordinate axes.

Abstract: A device is disclosed for use on a projection type semiconductive wafer precision step-and-repeat alignment and exposure system for on-machine inspection of a reticle containing the circuitry to be printed on the wafer. Two apertured optical detectors are aligned with identical portions of the projected image of the reticle and scanned across the image of the reticle. Any difference in the electrical response of the two optical detectors indicates dirt or a flaw in the reticle.

Abstract: In an X-Y addressable workpiece positioner, the workpiece to be positioned, such as a semiconductive wafer to be sequentially exposed at different regions thereof in accordance with a pattern of a mask, is disposed for movement with a work stage along coordinate X and Y axes. The work stage has a two-dimensional array of X and Y coordinate addressing indicia enclosed within a border and affixed to the work stage for movement therewith. A portion of an enlarged image of the array of addressing indicia is projected onto a sensor stage to derive an output indicative of the X and Y coordinates of the array of addressing indicia relative to the position of the sensor stage. The X and Y coordinates of the array of addressing indicia are sensed through addressing indicia recognition windows of the sensor stage and are differentially compared to remove unwanted background effects.

Abstract: In an X-Y addressable workpiece positioner the workpiece to be positioned, such as a semiconductive wafer to be aligned with a mask image, is coupled to move with a work stage moveable in the X-Y direction and having a two-dimensional array of positioning indicia affixed thereto for movement therewith. An enlarged image of a portion of the positioning array is projected onto a relatively stationary sensor stage to derive an output determinative of the X and Y coordinates of the positioning array relative to the position of the sensor. The sensed X and Y coordinates of the positioning array are compared with the X and Y coordinates of a reference positioning address to derive an error output. The work stage is moved in response to the error output for causing the workpiece to be positioned to the reference address.

Abstract: A projection lens is disposed directly above a vacuum chuck for projecting an image of an illuminated portion of a semiconductive wafer held thereby to an image plane where that image may be viewed through a pair of objective lenses of a compound microscope. Microcircuitry contained on a reticle held by a holder positioned above the projection lens is photometrically printed onto the semiconductive wafer by passing exposure light through the reticle and the projection lens to the semiconductive wafer. At least one fiber optic source of illuminating light and one or more optical lenses are employed for projecting an image of the fiber optic light source through the objective lens to an entrance pupil of the projection lens without passing through the reticle to provide uniform illumination of the semiconductive wafer and facilitate direct wafer alignment prior to photometrically printing on the semiconductive wafer.

Abstract: A step-and-repeat alignment and exposure system is provided with a main stage controlled for movement along orthogonal X and Y axes to position either a reference mark or a semiconductive wafer directly beneath a projection lens of the reduction type. The reference mark is formed on a reference mark plate mounted on a substage which is in turn mounted on the main stage and provided with adjustment screws for manually positioning the reference mark plate in a plane parallel to an image plane of the projection lens and for manually positioning the reference mark in alignment with one of the axes of motion of the main stage. Another stage is disposed above the projection lens and controlled for movement along the X and Y axes and about an orthogonal Z axis to position a reticle, held by a vacuum holder and selectively illuminated by a light source unit, with respect to the reference mark.

Abstract: A gas bearing is provided which has a spherically contoured pocket with a gas supply passage which opens in the center of the pocket. The gas bearing is coupled to the load and is supported by a stem and a ball joint through which the gas is supplied to the bearing. An additional passage allows gas to flow between the pocket and a closed chamber in the bearing.

Abstract: A motor-tachometer rotates a drive shaft rotatably supported on an upper support member that is fixedly secured to a lower support member. The drive shaft in turn rotates a compliant rotary member of larger diameter fixedly secured to a driven shaft for rotation therewith. This compliant rotary member is provided with a circular central portion and an annular outer portion coupled together by three springs symmetrically disposed around the periphery of the central portion, and is loaded against the drive shaft so that the annular outer portion is eccentrically offset relative to the circular central portion in a radial direction opposite the drive shaft. The driven shaft is rotatably supported by the lower support member in engagement with a drive bar for moving a stage on which the upper and lower support members are mounted along the drive bar.

Abstract: An illumination system having a light source disposed along a central axis of the system is provided with a conical reflector coaxially disposed about the light source for forming an annular virtual image of an arc of the light source. A toroidal lens is coaxially disposed about the central axis for forming a circular real image of the annular virtual image of the arc at the input port of a utilization device.

Abstract: An optical focusing system is provided for accurately focusing a wafer surface, thereby enabling the production of sharp microcircuit images. Accurate focusing is achieved despite non-parallel and non-flat wafer surfaces, despite differences in reflectivity of different portions of the wafer surface, and despite changes in environmental conditions such as temperature during system operation.The system comprises a full aperture focus detection apparatus, a kinematic lens positioning apparatus, and a kinematic wafer chuck differential leveling or positioning apparatus. The full aperture focus detection apparatus detects the extent to which a wafer surface is out of focus with respect to the image plane of a projection lens, and produces an amplified differential signal having magnitude and polarity indicative of the extent and direction, relative to the image plane, that the wafer surface is out of focus.

Abstract: A shutter is rotatably mounted in a housing for opening and closing a shutter aperture in the housing. The shutter is coupled to a drive unit for unidirectionally rotating the shutter with the same velocity profile to open and close the shutter aperture during each exposure period. This drive unit includes a drive motor and a control circuit having a source of position and velocity reference data and a feedback control loop configurable for either position or velocity control of the shutter as determined by a control command.

Abstract: A shutter is rotatably mounted within a housing for opening and closing a shutter aperture formed in the housing. The shutter is coupled to a drive unit for unidirectionally rotating the shutter with the same velocity profile to open and close the shutter aperture during each exposure period. This drive unit includes a source of position and velocity data and a feedback loop configurable for either position or velocity control of the shutter as determined by a control command.

Abstract: In an optical alignment and exposure machine, particularly suited for aligning semiconductive wafers with and exposing them to microelectronic circuit patterns, two stages of mechanical prealignment of the wafers are performed. In the first stage of mechanical prealignment a wafer is received at a prealignment station where the periphery of the wafer engages at least one of three belt-driven rollers in such a manner as to turn the wafer so as to align a flat side edge or alignment flat of the wafer with two of the three rollers. A transfer arm picks up the first-stage prealigned wafer and transfers it to a rotatable alignment and exposure chuck carried by an X-Y addressable work stage.

Abstract: A shock and vibration isolation system having a plurality of isolators supporting a utilization device is disclosed. Each isolator has two gas driven pistons, pivotally mounted in a frame and is connected to an accumulator/controller that supplies controlled amounts of pressurized gas. A sensor in each isolator senses the position of the utilization device with respect to a base sitting on the ground, and the accumulator/controller adds gas to or exhausts gas from the pistons to counteract changes in position detected by the sensor. An electronic control circuit is connected between the sensor and the accumulator/controller to supply a properly compensated signal from the sensor to control the accumulator/controller.

Abstract: A pair of position control circuits is employed for controlling the position of an interferometrically controlled stage along orthogonal X and Y axes of motion of the stage. Each of these position control circuits is provided with a variable phase shifter responsive to a reference signal and a control signal for producing an output signal of the same frequency as the reference signal but shifted in phase as determined by the control signal, and with a phase detector responsive to the output signal from the variable phase shifter and to a measurement signal obtained from the interferometrically controlled stage for producing a position control signal proportional to the difference in phase between those signals. The sum and the difference of the position control signals of selected phase produced by these position control circuits are employed to extend the resolution of the position control circuits.