Research On Hardware Platform For Dual-stage Precision Motion Control System

High performance motion-control hardware platform of the dual-stage lithography is one of the key factors guaranteeing the performance of lithography. Supported by "Eleventh Five-Year" national key project-"Turbo-Scan lithography system prototype development", the ultra-precision motion control system hardware platform of the dual-stage lithography is researched and practiced in this dissertation.Lithography requires high-speed, large stroke,6-DOF, and nanometer level precision synchronous scanning motion. The synchronous motion precision of the wafer stage and the reticle stage in the65nm lithography are MA<3.2nm and MSD<7nm; the movement of the dual-stage involves more than synchronized control of the40motion axes. Hundreds of drivers, sensors need to be monitoring control precisely and much date must be high-speed processed in the dual-stage system. And the high-performance multi-processor parallel control structure is needed to meet the control, computing and information processing of the dual-stage system.This dissertation introduces the mechanical structure and the motion structure of the dual-stage system, describes its control scheme, researches and analyzes a he ultra-precision motion control system hardware platform of the dual-stage lithography. The mechanical structure which the fine stage is stacked on the coarse one is applied to the reticle stage and the wafer stage. Long stroke coarse movement stage mainly to achieves the long-distance high-speed, high-acceleration motion control goals; short-stroke micro movement stage mainly achieves high precision motion control objectives through the real-time compensation for coarse movement stage motion errors. The dual-stage motion control system must implement nanometer-level synchronous motion control to more than40axes; its motion control units need to achieve a large amount of complex control algorithms for of different servo axes in a short period. These algorithms include laser measurement model solver algorithms, location-acceleration feedback control algorithm, precise trajectory interpolation algorithm, the Lorentz force decoupling algorithm and so on. The dual-stage motion control system also need to measure each movement element position, monitor such as the motor temperature, the light intensity of the laser interferometer signal, the pressure of the flotation rail, the ambient temperature and pressure and so on and control the trip switch for a variety of digital switch. Multi-axis synchronization control requires a motion control system with the multi-processor parallel processing capability; the complexity and the real-time requires a motion control computing unit with the superior computing power and high-speed processing capability; Switching between multiple measurement systems and the data acquisition of hundreds of sensors involve multi-source, multi-target complex data transmission, in addition, the computing involves sharing data between multiple processors real-time interaction, which require motion control system with multi-bus high-speed high-performance data exchange capability.In response to these capacity needs this dissertation designs a lithography multi-dimensional dual-stage ultra precision motion control hardware platform. In this hardware platform, a master-slave multi-processor parallel processing architecture technique based on VME bus was adopted to meet the ultra-precision motion control involving up to40axes and the various algorithms divided; designs a parallel architecture technology and a distributed shared memory mechanism technology based on the custom local bus to ensure high-speed computing and multi-processor synchronization and completes the servo data storage and real-time data exchange between multiple boards participating the servo operation within the specified servo period; for many sensor signal of the motion control system, in order to meet the real-time and synchronization of the data acquisition, to reduce the difficulty of realization, to avoid drift interference, to reduce cables, the high-speed high-precision signal acquisition control technology based on the high-speed fiber link is proposed.Currently, this hardware platform has been fully applied in major projects, and its stability and reliability are good. In addition, the hardware platform has good flexibility, which has been used for the stage system with the "十" shaped structure, flotation+the stage system with "H"-type structure, now is being used in the flotation+the dual-stage system with plane motor. And this hardware platform also can be used for the coming maglev+the dual-stage system with the plane motor.