步进扫描光刻机扫描运动轨迹规划及误差控制

Trajectory Planning and Precision Control of Scan-move for Step-scan Lithography Stage

研究一种步进扫描投影光刻机工作台扫描运动超精密轨迹规划算法及误差控制策略。在分析三阶扫描运动与步进运动轨迹规划异同点的基础上,提出三阶扫描运动轨迹规划算法。针对扫描运动精确性与严格同步性要求,分析扫描运动轨迹规划误差补偿的几个关键问题。根据扫描运动轨迹算法离散实现存在的误差,结合内部整数积分策略,提出扫描运动轨迹规划加减速段与扫描速度稳定段运动距离的离散积分策略误差控制方法。此外,为克服切换时间圆整引起的扫描曝光匀速段位置误差,提出一种基于常速扫描运动段位置修正因子的误差补偿方法。以上方法共同实现光刻机工作台扫描运动轨迹规划精度控制。实例证明提出算法是有效和精确的。该算法成功应用于100nm步进扫描投影光刻机工作台的超精密运动控制系统中。

A trajectory planning method and precision control strategies for scan-move of step-scan projection lithography are investigated. The difference of trajectory planning between step-move and scan-move is firstly discussed. Aiming at the requirements of accuracy and strict synchronization of scan-move, several key issues are analyzed. Considering the accuracy losses in discrete-time implementation of trajectory planning algorithm, the integration strategy in discrete-time domain of precision control of trajectory planning is presented with combination of internal integer integration strategy. Furthermore, a compensation method with a correcting factor of constant velocity scan phase is advanced; Experiment results demonstrate that the proposed trajectory planning algorithm and its precision compensation strategy are accurate and effective. These methods are successfully applied in ultra-precision motion control system of 100 nm step-scan projection lithography equipment.