Abstract: A stage assembly includes a stage, a base assembly, a stage mover, and a temperature adjuster. The temperature adjuster includes a first plate, a first thermal insulator, a circulation housing, a first fluid system, and a second fluid system. The first plate is positioned adjacent to a conductor array of the stage mover. The first thermal insulator is positioned adjacent to the first plate. The circulation housing defines at least a portion of a housing passageway that is positioned adjacent to the first thermal insulator. The first fluid system directs a first circulation fluid through the housing passageway, and the second fluid system directs a second circulation fluid through the first plate channel. With this design, the second circulation fluid removes the majority of the heat from the conductor array, and the first circulation fluid shields an outer surface of the circulation housing from thermal disturbance.

Abstract: A mover (344) moving a stage (238) along a first axis, along a second axis and along a third axis includes a magnetic component (354), a conductor component (356), and a control system (324). The magnetic component (354) includes a plurality of magnets (354D) that are surrounded by a magnetic field. The conductor component (356) is positioned near the magnetic component (354) in the magnetic field. Further, the conductor component (356) interacts with the magnetic component (354) when current is directed to the conductor component (356) to generate a controllable force along the first axis, a controllable force along the second axis, and a controllable force along the third axis. The conductor component (356) can include a split coil design, having a first conductor array (356A) and a second conductor array (356B) that is positioned substantially adjacent to the first conductor array (356A).

Abstract: A method for determining a commutation offset for a mover (250A) of a mover assembly (220C) that moves and positions a stage (220A) relative to a stage base (220B) includes controlling the mover assembly (220C) in a closed loop fashion to maintain the position of the stage (220A) along a first axis and along a second axis with the stage (220A) levitated above the stage base (220B). The method also includes the steps of (i) directing current to a coil array (240) of the mover assembly (220C) so that the mover assembly (220C) imparts a disturbance on the stage (220A); and (ii) evaluating one or more forces generated by the mover assembly (220C) as a result of the disturbance on the stage (220A) created by the mover (250A). Further, a method for generating a compensation map (1402) includes sequentially directing a plurality of excitation signals to the control of the mover assembly (220C) and determining the control commands that result from the plurality of excitation signals.

Abstract: A method for determining a commutation offset for a mover (250A) of a mover assembly (220C) that moves and positions a stage (220A) relative to a stage base (220B) includes controlling the mover assembly (220C) in a closed loop fashion to maintain the position of the stage (220A) along a first axis and along a second axis with the stage (220A) levitated above the stage base (220B). The method also includes the steps of (i) directing current to a coil array (240) of the mover assembly (220C) so that the mover assembly (220C) imparts a disturbance on the stage (220A); and (ii) evaluating one or more forces generated by the mover assembly (220C) as a result of the disturbance on the stage (220A) created by the mover (250A). Further, a method for generating a compensation map (1402) includes sequentially directing a plurality of excitation signals to the control of the mover assembly (220C) and determining the control commands that result from the plurality of excitation signals.

Abstract: An exemplary stage apparatus has a motor, stage, and position-measuring device. The motor has a planar stator and moving-coil mover (planar motor). The stator is a checkerboard magnet array extending in an x-y plane and producing a magnetic field having a field period of 2? in a u-v coordinate system rotated 45° from the x-y coordinate system of the plane. The stage, coupled to the mover, moves with corresponding motions of the mover relative to the stator. The position-measurement device includes a first group of four magnetic-field sensors that are movable with the stage. The sensors are situated at integer multiples of ?/2 from each other in u- and v-directions of the u-v coordinate system. The sensors produce respective data regarding a respective component of the magnetic field at, and hence the position of, the respective sensor within the period of the magnetic field.

Abstract: An exemplary stage assembly has movable stage mass and counter-mass. A stage motor is coupled to the stage mass and counter-mass such that stage-mass motion imparted by the stage motor causes a reactive motion of the counter-mass counter to the motion of the stage mass. At least one trim-motor is coupled to the counter-mass. A control system commands the trim-motor to regulate movement of the counter-mass in reaction to stage-mass motion. A PI feedback controller receives the following-error of the counter-mass and generates corresponding center-of-gravity (CG) force commands and trim-motor force commands to the trim-motor(s) to produce corrective counter-mass motion. A trim-motor force limiter receives trim-motor force commands and produces corresponding limited trim-motor force commands that are fed back as actual CG force commands to the feedback controller to modify integral terms of the feedback controller according to the limited trim-motor force commands.

Abstract: Methods, apparatus, and systems are disclosed for identifying force-ripple and/or side-forces in actuators used for moving a multiple-axis stage. The identified force-ripple and/or side-forces can be mapped, and maps of corresponding position-dependent compensation ratios useful for correcting same are obtained. The methods are especially useful for stages providing motion in at least one degree of freedom using multiple (redundant) actuators. In an exemplary method a stage member is displaced, using at least one selected actuator, multiple times over a set distance in the range of motion of the subject actuator(s). Each displacement has a predetermined trajectory and respective starting point in the range. For each displacement, respective section force-command(s) are extracted and normalized to a reference section force-command to define a section compensation-ratio.

Abstract: Electromagnetic actuators are disclosed having at least one actively cooled coil assembly. Exemplary actuators are linear and planar motors of which the cooled coil assembly has a coil having first and second main surfaces. A respective thermally conductive cooling plate is in thermal contact with at least one main surface of the coil. Defined in or on each cooling plate is a coolant passageway that conducts a liquid coolant. A primary pattern of the coolant passageway is coextensive with at least part of the main surface of the coil. The primary pattern can have a secondary pattern through which coolant flows in a manner reducing eddy-current losses. An exemplary secondary pattern is serpentine. An exemplary primary pattern is radial or has a radial aspect, such as an X-shaped pattern. The devices exhibit reduced eddy-current drag.

Abstract: Embodiments of the invention provide improved thermal conductivity within, among other things, electromagnetic coils, coil assemblies, electric motors, and lithography devices. In one embodiment, a thermally conductive coil includes at least two adjacent coil layers. The coil layers include windings of wires formed from a conductor and an insulator that electrically insulates the windings within each coil layer. In some cases the insulator of the wires is at least partially absent along an outer surface of one or both coil layers to increase the thermal conductivity between the coil layers. In some embodiments, an insulation layer is provided between the coil layers to electrically insulate the coil layers. In some cases the insulation layer has a thermal conductivity greater than the thermal conductivity of the wire insulator.

Abstract: Methods and apparatus for adjusting the amount of current provided to a magnetic actuator to compensate for a temperature change associated with the magnetic actuator are disclosed. According to one aspect of the present invention, an apparatus includes an actuator, which has at least one magnet and an associated force constant. The apparatus also includes a temperature sensing arrangement and a control arrangement, the temperature sensing arrangement being arranged to determine or measure a temperature of the magnet. The control arrangement adjusts the current provided to the actuator based on the temperature of the magnet. The current is adjusted to maintain a correct or desired force in light of temperature-induced variations to a force constant.

Abstract: Embodiments of the invention compensate for one or more effects of a stage motor in a precision stage device. A feedforward module receives an input signal corresponding to the effect of the motor and generates a feedforward control signal that can be used to modify a motor control signal to compensate for the effect of the motor. In some embodiments, a control system is provided to compensate for a back-electromotive force generated by a motor, while in other embodiments, a control system may compensate for an inductive effect of a motor. Embodiments of the invention may be useful in precision stage devices, for example, lithography devices such as steppers and scanners.

Abstract: A mover (344) moving a stage (238) along a first axis and about a second axis includes a magnetic component (454), and a conductor component (456). The magnetic component (454) includes one or more magnets (454D) that are surrounded by a magnetic field. The conductor component (456) is positioned near the magnetic component (454) in the magnetic field. Further, the conductor component (456) interacts with the magnetic component (454) when current is directed to the conductor component (456) to generate a controlled force along the first axis, and a controlled moment about the second axis. Additionally, the conductor component (456) interacts with the magnetic component (454) to generate a controlled force along a third axis that is perpendicular to the first axis and the second axis when current is directed to the conductor component (456).

Abstract: According to one aspect of the present invention, a motor arrangement includes at least one coil, a cover plate, and a shield layer. The at least one coil has a first side and a second side. The cover plate is positioned substantially over the first side of the at least one coil at a distance from the at least one coil. The shield layer is positioned between the first side of the at least one coil and the cover plate, and has a top surface. The top surface contacts the cover plate, and includes a liquid and a gas that form a mixture and cause the top surface to have a substantially constant temperature.

Abstract: A mover (344) moving a stage (238) along a first axis, along a second axis and along a third axis includes a magnetic component (354), a conductor component (356), and a control system (324). The magnetic component (354) includes a plurality of magnets (354D) that are surrounded by a magnetic field. The conductor component (356) is positioned near the magnetic component (354) in the magnetic field. Further, the conductor component (356) interacts with the magnetic component (354) when current is directed to the conductor component (356) to generate a controllable force along the first axis, a controllable force along the second axis, and a controllable force along the third axis. The conductor component (356) can include a split coil design, having a first conductor array (356A) and a second conductor array (356B) that is positioned substantially adjacent to the first conductor array (356A).

Abstract: A lithography apparatus includes a projection optical system that projects an image of a pattern, a first support member, a second support member that is flexibly coupled to the first support member by a first flexible coupling device such that the second support member is suspended from the first support member, and a second flexible coupling device that flexibly couples the projection optical system to the second support structure. This arrangement is capable of improving the vibration characteristics of the projection optical system.

Abstract: Methods, apparatus, and systems are disclosed for identifying force-ripple and/or side-forces in actuators used for moving a multiple-axis stage. The identified force-ripple and/or side-forces can be mapped, and maps of corresponding position-dependent compensation ratios useful for correcting same are obtained. The methods are especially useful for stages providing motion in at least one degree of freedom using multiple (redundant) actuators. In an exemplary method a stage member is displaced, using at least one selected actuator, multiple times over a set distance in the range of motion of the subject actuator(s). Each displacement has a predetermined trajectory and respective starting point in the range. For each displacement, respective section force-command(s) are extracted and normalized to a reference section force-command to define a section compensation-ratio.

Abstract: Methods are disclosed for operating at least one commutated actuator (generally termed a “linear actuator”) while compensating for error-inducing phenomena such as force-ripple and side-force. An exemplary method includes determining a set of commutation equations that substantially provide desired forces for the actuator in one or more directions. A map is generated of actual forces produced by the actuator in the one or more directions in proportion to coefficients of the commutation equations. Corrected commutation coefficients are determined from the desired forces and the map of actual forces. Electrical current is applied to the actuator using the commutation equations with the corrected coefficients. The methods are applicable to actuators having one degree of freedom (DOF) of motion or multi-DOF actuators, and are applicable to actuators that run on single-phase power or multi-phase power.

Abstract: “Hexapod” mountings are disclosed for use with optical elements. An exemplary mounting includes a base, a platform that is movable relative to the base, and six legs having nominally identical length. Three pairs of legs, having substantially equal stiffness, extend between the base and platform and support the platform relative to the base. In each pair of legs, respective first ends are coupled together in a ?-shaped manner forming a respective apex. Respective second ends are splayed relative to the apex, desirably forming an angle of substantially 109.5° at the apex. The apices are mounted equidistantly from each other on a circle on the platform. The respective second ends of the pairs of legs are mounted at respective locations on a circle on the base. The axes of each pair of legs define a respective leg plane substantially perpendicular to the base plane. Each leg has an actuator that, when energized, changes a length of the respective leg.

Abstract: Methods and apparatus for providing a fine stage with up to six degrees of freedom are disclosed. According to one aspect of the present invention, a stage apparatus includes a first stage assembly, a second stage assembly, and a countermass arrangement. The first stage assembly including a first component of a first actuator, and supports a second actuator arrangement. The second stage assembly is supported over the first stage assembly such that the second actuator arrangement drives the second stage assembly along a vertical axis. The countermass arrangement includes a second component of the first actuator. The first component cooperates with the second component to allow the first stage assembly to move relative to a first horizontal axis. The countermass arrangement absorbs reaction forces associated with the first and second stage assemblies.