为提高光刻机工件台的跟踪精度和响应速度,采用了以直线电机和音圈电机为执行器的宏微控制结构.微动台完成高精度小行程运动,宏动台实现大行程运动同时保证音圈电机不出现位移饱和.通过滑模变结构方法设计控制器以提高控制系统的鲁棒性.根据频率整型法设计了时变滑模面,可以起到低通滤波的效果.变增益切换控制律可以有效地减小抖振现象.仿真结果表明,曝光扫描过程中的最大位置偏差为8.7 nm,标准差为2.2 nm.扫描速度保持平稳,同时位置偏差信号的高频分量被有效抑制.%To improve the tracking precision and respond speed, a macro-micro control structure is chosen and the actuators are the linear motor and voice motor. The micro stage accomplishes the short-stroke movement and ensures the high tracking precision, and the macro stage makes large-stroke movement to keep that the voice motor is not closed to saturation. The control system is designed based on sliding mode control theory to ensure the robust of the control system. In order to achieve low-pass effect, an optimal integral sliding surface is designed based on frequency-shaped method. A variable gain switch control law is introduced to reduce chattering. Simulation results show that the maximum position tracking error and standard deviation is 8.7 nm and 2.2 nm during the scanning exposure process. Scanning speed is smooth and high frequency components of position error signal have been reduced effectively.
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