Trajectory planning scheme for ultra-precision system

As equipment used for IC manufacturing must meet a wide range of complicated requirements, improving the efficiency and accuracy of multi-degree-of-freedom motion positioning systems,which are widely used in the design of various stages of IC manufacturing,has become a contentious research topic. Thus,this study proposes a critical trajectory-planning scheme for application in an ultra-precise and multi-motion stage. The goal of the trajectory planning is to control nanometer-level accuracy while improving technical efficiency in fine-tuning. The optimization trajectory model is based on the practical situation and the requirements of the real processes. A differential evolutionary approach is used to modify the controller setting,and a reference trajectory is derived using an iterative Monte Carlo approach based on the actual tracking performance of the controller as the optimization target. Simulations and experiments are performed using a physical system,and the data analysis demonstrates a fast convergence of the tracking errors,with approximately 90% reduction in the level of parameter fine-tuning while maintaining the repeat positioning precision of the stage below ±5 nm/3σ. The experimental results indicate that the proposed scheme can enhance the working efficiency of a motion system towards its required accuracy while maintaining a high level of positioning precision. © 2023 Chinese Academy of Sciences. All rights reserved.