应用于光刻机掩模台的自适应前馈控制

Adaptive Feedforward Control for Reticle Stage of Lithography

为了解决光刻机掩模台控制系统中模型参数的不确定性,提出一种带有自适应前馈的运动控制算法。该算法主要特点是以控制器的实际输出与估计输出之间的估计误差最小为优化目标,利用递推最小二乘法在线自动更新前馈系数,使前馈系数更为准确地匹配系统的运动特性。将此方法应用在光刻机掩模台上,利用四阶点对点运动轨迹作为参考位置信号进行仿真实验,验证此控制算法的控制效果。与传统方法相比,自适应前馈控制有效地减小位置误差、缩短了稳定时间,并提升了掩模台系统性能。

In order to solve the uncertainty of model parameters in the control system for reticle stage of lithography,a motion control algorithm with adaptive feedforward is proposed.The main feature of the algorithm is to minimize the estimation error between the actual output and the estimated output of the controller as the optimization goal.The recursive least squares method is used to automatically update the feedforward coefficient online,so that the feedforward coefficient can match the motion characteristics of the system more accurately.This method is applied to the reticle stage of lithography,and the fourth-order point-to-point motion trajectory is used as the reference position signal for simulation experiments to verify the control effect of this control algorithm.Compared with the traditional method,the adaptive feedforward control effectively reduces the position error,shortens the settling time,and improves the performance of the reticle stage system.