Abstract:
PROBLEM TO BE SOLVED: To provide lithographic equipment capable of improving the throughput without sacrificing the overlay performance. SOLUTION: Lithography equipment has a movable object and a control system for controlling the position of the movable object. The control system comprises a position measuring system for measuring the position of the movable object, a comparing unit for generating a servo error signal by subtracting a position signal which shows the actual position of the movable object from a reference signal, a control unit for generating a first control signal based on the servo error signal, a feedforward unit for generating a feedforward signal based on the reference signal, an adding unit for generating a second control signal by adding the first control signal and the feedforward signal, and an actuator for making the movable object operate. The gain of the feedforward unit depends on the position of the movable object. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a system that controls a high-precision motion such as a stepping and scanning operation of a lithography projection apparatus, i.e., a flexible control system that combines lower feed-forward control and iterative learning control with no need of manual adjustment while being simple, plus being adaptive to a slow change of a motion system. SOLUTION: This motion control system takes into consideration a snap s, a jerk j, an accelerated velocity a, and a velocity v that are all the targets of control, begins respective feed-forward coefficients kfs, kfj, kfa, and kfv with initial settings, and learns until there will be no difference between a desired motion and a real motion, repeating updates. This will enable feed-forward adjustment to be automated, and to be easily executed by being combined with existing motion control software, and will eliminate manual adjustment steps, and adapt the system to a slow change since it is continuously updated. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
A projection system (PS) is provided that includes a sensor system (20) that measures at least one parameter that relates to the physical deformation of a frame (10) that supports the optical elements (11) within the projection system (PS), and a control system (30) that, based on the measurements from the sensor system (20), determines an expected deviation of the position of the beam of radiation projected by the projection system (PS) that is caused by the physical deformation of the frame (10).