Abstract: A strategy of ultra-precision motion control and synchronization control for stage of step & scan lithography is studied, aiming at the motion performance of synchronization scan. Considering the stage structure, a control method based on rough-fine motion is presented, which is described as: fine-motion stage moves nanometer level and rough-motion stage follows at micrometer level. The synchronization state of stage during scanning is planned based on the 3rd trajectory planning and trajectory overlapping. To realize the synchronous motion precision of nanometer level, a cross-feedback control strategy is proposed which makes the retile stage track the wafer stage motion trend based on the difference of dynamic characteristic between wafer stage and retile stage, and also a synchronous error model is designed to evaluate the motion performance of stage. The control method proposed is applied in 100 nm step & scan projection lithography and obtains good results.

Key words: Motion control, Stage, Synchronization control, Synchronization state