Patent application number | Description | Published |
20080275661 | On-machine methods for identifying and compensating force-ripple and side-forces produced by actuators on a multiple-axis stage - 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. Multiple section compensation-ratios are assembled, as functions of displacement in the range, to provide a map of compensation ratios for the actuator(s) throughout the range. | 11-06-2008 |
20080278705 | STAGE ASSEMBLY WITH MEASUREMENT SYSTEM INITIALIZATION, VIBRATION COMPENSATION, LOW TRANSMISSIBILITY, AND LIGHTWEIGHT FINE STAGE - A stage assembly ( | 11-13-2008 |
20080291464 | INTERFEROMETRIC POSITION-MEASURING DEVICES AND METHODS - 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. | 11-27-2008 |
20090237793 | ACTIVE-ISOLATION MOUNTS FOR OPTICAL ELEMENTS - Disclosed are, inter alia, optical components that include an optical element (e.g., mirror) and at least three active-isolation mounts mounting the optical element to a frame (e.g., optical barrel or optical frame). An active-isolation mount has a non-contacting actuator connecting a respective location on the optical element to the frame and provides movability of the respective location relative to the frame in at least one direction. At least one displacement sensor is associated with each respective location on the optical element. The displacement sensors are sensitive to displacements of the respective locations in at least one respective direction and reference the displacements to an absolute reference. The actuators and sensors are connected to a servo control loop to provide feedback control. | 09-24-2009 |
20110043781 | Projection optical device and exposure apparatus - A projection optical device includes a projection optical system which projects an image of a pattern, a support member attached to the projection optical system, and a plurality of coupling members connected to the support member. The coupling members suspend and support the projection optical system through the support member from an upper direction of the support member. The projection optical device can include a frame to which one end of each of the coupling members is attached, such that the projection optical system hangs from the frame via the support member and the coupling members. A projection optical device also can include a liquid supply which supplies a temperature-controlled liquid to a side surface of a projection optical system utilizing gravity to cause the temperature-controlled liquid to flow along the side surface of the projection optical system. | 02-24-2011 |
20110242660 | DIRECT DERIVATIVE FEEDFORWARD VIBRATION COMPENSATION SYSTEM - Methods and apparatus for providing vibration compensation using position measurements are disclosed. According to one aspect of the present invention, a method of compensating for vibrations of an object includes obtaining a plurality of position measurements associated with the object. The method also includes processing the plurality of position measurements to determine a derivative acceleration, and determining a compensatory force to counteract the vibrations of the object. Determining the compensatory force includes using the derivative acceleration. Finally, the method includes applying the compensatory force to the object. | 10-06-2011 |
20120113405 | METHOD FOR DETERMINING A COMMUTATION OFFSET AND FOR DETERMINING A COMPENSATION MAP FOR A STAGE - A method for determining a commutation offset for a mover ( | 05-10-2012 |
20120127445 | ISOLATION SYSTEM FOR AN OPTICAL ELEMENT OF AN EXPOSURE APPARATUS - An optical isolation assembly ( | 05-24-2012 |
20120127447 | METHOD FOR DETERMING A COMMUTATION OFFSET AND FOR DETERMINING A COMPENSATION MAP FOR A STAGE - A method for determining a commutation offset for a mover ( | 05-24-2012 |
20130182235 | MEASUREMENT SYSTEM THAT INCLUDES AN ENCODER AND AN INTERFEROMETER - A stage assembly ( | 07-18-2013 |
20140055060 | LINEARIZED CONTROL OF PIEZOELECTRIC ACTUATOR TO REDUCE HYSTERESIS - An exemplary piezoelectric actuator includes a piezoelectric transducer that exhibits displacements when energized with corresponding voltages. A control system is electrically connected to the piezoelectric transducer so as to provide the transducer with the voltages. The control system includes feedback of displacements of the transducer as functions of respective voltage commands and feed-forward of electrical currents passing through the transducer as functions of the respective voltages applied to the transducer. The control system further has a feedback controller connected to receive transducer-displacement data corresponding to the voltages applied to the transducer. The control system further can include a current-feed-forward amplifier connected to receive transducer-current data corresponding to the voltages applied to the transducer. Such a control system facilitates reduction of hysteresis in controlled actuation of the actuator. | 02-27-2014 |