摘要:
A stage assembly (220) for moving a device (200) includes a stage (208), an attraction-only type actuator pair (426) that moves the stage (208), and a control system (24). In one embodiment, the actuator pair (426) includes a first electromagnet (436F), a first conductor (438F) and a first target (440F) having a first target surface (442F). The actuator pair also includes a second electromagnet (436S), a second conductor (438S) and a second target (440S) having a second target surface (442S). The first electromagnet (436F) is positioned at a first angle θ1 relative to a first target surface (442F) and the second electromagnet (436S) is positioned at a second angle θ2 relative to the second target surface (442S). The control system (24) directs a first current to one or more of the electromagnets based on at least one of the angles θ1, θ2. Further, one or more electromagnets (436) can include a first measurement point and a second measurement point. The control system (24) can direct current to the actuator pair (426) based on the relative distance between the first and second measurement points and the corresponding target surface (442).
摘要:
A position control apparatus for synchronously controlling the movement of fine stages in a high-precision scanning positioning instrument. The position control apparatus uses actuators to adjust the fine stages with six degrees of freedom. By adjusting the fine stages, any synchronous errors between the fine stages during scanning may be dynamically corrected. Further, the fine stages may be adjusted during periods of acceleration and deceleration to reduce the settling time and consequently increasing throughput. Encoders directly attached to the actuators produce signals that are used in a velocity feedback loop. The locations of the fine stages are measured by interferometers. The position control apparatus uses a position control circuit to control the actuators to compensate for synchronous error.
摘要:
A precision assembly (210) for positioning a device (226) includes a stage (260) that retains the device (226), a dual mover assembly (228) that moves the stage (260), and the device (226) along a movement axis (266), a measurement system (222) and a control system (224). The dual mover assembly (228) includes a first mover (262) that moves the stage (260) along the movement axis (266) and a second mover (264) that moves the device (226) along the movement axis (266). The second mover (264) is rigidly coupled to the first mover (262) so that movement of the first mover (262) results in movement of the second mover (264). Further, the total output of the dual mover assembly (228) along the movement axis (266) is equal to the sum of the movement of the first mover (262) and the movement of the second mover (264). The measurement system (222) measures a movement position along the movement axis (266). The control system (224) controls the dual mover assembly (228) utilizing the movement position. The control system (224) is designed to effectively decouple the control of the first mover (262) from the control of the second mover (264). Further, the control system (224) includes a quantization feedforward loop.
摘要:
Process tools and methods are disclosed that involve interferometric and other measurements of movements and positions relative to a process position, such as movements and positions of a stage relative to a lithographic optical system. An exemplary apparatus includes a stage that places a workpiece relative to the tool, and that is movable in at least one direction relative to the tool. At least one first interferometer system is situated relative to the stage to determine stage position in a movement direction relative to the process position. A movement-measuring device determines displacement of the tool from the process position. Using data from the interferometer system and movement-measuring device a processor determines a position of the stage relative to the tool. The processor also corrects the determined position for displacement of the tool.
摘要:
A stage assembly (220) that moves a work piece (200) about a first axis and along a first axis includes a first stage (238), a second stage (240) that retains the work piece (200), a second mover assembly (244), a measurement system, and an initialization system (1081A). The second mover assembly (244) moves the second stage (240) relative to the first stage (238) about the first axis. The measurement system (22) monitors the position of the second stage (240) about the first axis when the second stage (240) is positioned within a working range about the first axis. The initialization system (1081A) facilitates movement of the second stage (240) about the first axis when the second stage (240) is rotated about the first axis outside the working range. The second mover assembly (244) can include a mover (255) and a dampener (410) that reduces the transmission of vibration from the first stage (238) to the second stage (240). In addition, the stage assembly (220) can include a control system (24) that directs power to the mover (255) to position the second stage (240) and to compensate for vibration of the first stage (238).
摘要:
Embodiments of the invention relate to a cable force feedforward approach that takes into account the cable force in the counter-mass trajectory computation to reduce or eliminate vibration of the lens body caused by the cable force disturbance and corrective force exerted by the trim motors. In one embodiment, a method provides cable force feedforward control for a counter-mass of a stage with a cable connected to the counter-mass and using the cable force feedforward control to control one or more trim motors to produce a trim motor output force to be applied to the counter-mass, the counter-mass moving in response to a reaction force from movement of the stage. The method comprises measuring a counter-mass position y of the counter-mass in response to forces applied to the counter-mass; measuring a cable force ƒ exerted on the counter-mass by the cable which is connected to the counter-mass; generating a cable force function {circumflex over (ƒ)}(y, {dot over (y)}) of the measured cable force ƒ versus the counter-mass position y; and computing the trim motor output force u as u ≅ - f + w · f ^ ( y , y . ) , where w is a weighting function having a value from 0 to 1 and is selected for optimization.
摘要:
Methods and apparatus for actively damping vibrations associated with a optical assembly of a photolithographic system are disclosed. According to one aspect of the present invention, an assembly that provides damping to a structure of a photolithographic apparatus that is subject to structural oscillations includes a counter mass, an active mechanism, an a controller. The active mechanism is coupled to the structure, supports the counter mass, and applies a force to the structure to counteract structural oscillations in the structure. The controller controls the force applied by the active mechanism on the structure, and utilizes information associated with movement of the structure to control the force.
摘要:
Methods and apparatus for isolating or separating a reticle stage arrangement from a lens assembly are disclosed. According to one aspect of the present invention, an apparatus includes a reticle stage assembly, a lens assembly, and an isolator assembly. The isolator assembly is arranged to substantially prevent vibrations from being transmitted from the reticle stage assembly to the lens assembly. In one embodiment, the apparatus also includes a frame structure that supports the lens assembly and the reticle stage assembly.
摘要:
A high-precision scanning positioning system with magnification and orthogonality correction. A scanning position system, such as a microlithographic system, has a mask fine stage and a plate fine stage mounted on a coarse stage that moves at a constant velocity during exposure. By moving one fine stage relative to the other fine stage in the same or opposite direction of the scan during the exposure of the plate, an increase or decrease in magnification may be achieved. Likewise, by moving one fine stage relative to the other fine stage perpendicular to the direction of the scan during the exposure, a change in orthogonality may be achieved, and by rotating one fine stage relative to the other, correction of any rotation error may be achieved. A position control apparatus controls the motion of the fine stage relative to the other fine stage, such that the scanning position system can simultaneously correct synchronous error between the fine stages and reduce settling time while changing the magnification and orthogonality.
摘要:
In a stage assembly, for instance a fine stage using a pair of push-pull electro-magnetic actuators to move the stage back and forth along an axis, there is typically a sensor to determine the actual stage location. This sensor's home position must correspond to the actual stage position where the two opposed actuators are observed to exert forces of the same magnitude but opposing directions on this stage. Since the actuators depend on the sensor reading to exert their forces correctly, misalignment of the home position will decrease system performance. The calibration of this sensor is accomplished using actual system feedback signals, which are the currents drawn by the two opposed actuators, during run time conditions. The sensor is considered calibrated (meaning a virtual “null” position) when each of the two opposed actuators draws the same amount of current. If this is not the case a feedback process calibrates the sensor.