Synchronization Control Based On Phase Compensation Of Tracking Error Of Wafer And Reticle Stage In Step And Scan Lithographic Equipment

Quality of exposures in step and scan lithographic equipment highly depends on the synchronization of wafer and reticle stage. In order to increase the synchronization between the two stages, a high precision synchronization control method for scanning movement of reticle and wafer stage based on phase compensation of tracking error with the same frequency is presented. This method is quite different from the traditional ones, which just focus on designing the synchronization control systems of wafer and reticle stage. In this paper, with the analysis of relationship between MA, MSD and correlation of tracking errors, the estimation of tracking error and the phase compensation with same frequency, the performance of synchronization control for reticle and wafer stage is improved notably. Compared with the traditional ones, this method has advantage of higher precision, lower cost and greater portability.