Motion Control for wafer stage of 0.1μm lithography

In this paper, a particular mechanical servo system is presented based on the design requirement of scanning wafer stage of 0. 1μm lithography. In order to achieve high accuracy and high speed, linear motor and voice coil motor is employed to control long stroke motions and short stroke motions, respectively. Considering extraneous forces resident in the system, a composite movement model with disturbing compensation employing an open-closed-loop D-type Iterative Learning Controller(ILC) is then given. The results of actual application demonstrate that the given system with better robustness can enhance the real-time tracing ability and can satisfy high accuracy at high speed along specified trajectories.