Iterative Learning Control: Feasibility and Implementation for a Reticle Stage

ASML is always searching for improvements in reducing the servo error of both the Wafer Stage and the Reticle Stage of their lithography machines. Due to the repetitive motion and corresponding repetitive servo error of the Reticle Stage Short Stroke (RSSS), Iterative Learning Control (ILC) can be a powerful method to further reduce the servo...