Design of a synchronization control system for lithography based on repetitive control method

摘要

A repetitive control theory is proposed to solve the synchronization problem between the wafer stage and reticle stage.A macro-micro control method is used based on a macro-micro control structure in which a linear motor is combined with a voice coil motor.A synchronization controller of the reticle stage is added base on the conventional PID control system.The repetitive controller is designed based on the repeated movement of the reticle stage and the wafer stage during the scan and exposure period,and the effects of synchronization control system can be improved because of the repetitive control can effectively track and inhibit the periodicity excitation signal.The repetitive control system effectively reduces the synchronization error during the scan and exposure period,in the meanwhile keep the tracking accuracy and dynamic characters.Simulation results show that the synchronization error can be reduced effectively.