Method And Control Of Synchronization Error Correction On The Stage Of Step-and-scan Lithography

Technology of precision stage, as one of the three core technology of lithography,has a crucial role in lithography alignment and exposure. In the step&scan lithography,the synchronization performance between wafer stage and reticle stage has significanteffect on critical dimension, overlay and throughput. To improve the synchronizationperformance between wafer stage and reticle stage, a series of research has been donein this dissertation.Firstly, according to the coarse-fine structure of wafer stage and reticle stage,coarse-fine control strategy are analyzed. Dynamical model and control model ofwafer stage and reticle stage are established base on the working principle of waferstage an reticle stage.Secondly, based on elaborating the coupling effect between the coarse stage andthe fine stage, coordinated synchronized motion control structure and Fuzzy-PIDcontrol strategy of synchronization error are proposed. The Fuzzy-PID controller hasbetter performance than PID control strategy by simulation analysis in Matlab.Finally, according to operating principle of dual-stage synchronized motion,FPGA as the core of control system is designed. And then, the implementation methodof main modules and the design method of PCB circuit board are introduced in detail.Based on the previous research, experiment study of the synchronized motioncan be implemented. Limited laboratory conditions, preliminary measurementpositioning error of the two motor are-0.644μm and1.014μm. MA and MSD are5μmand9μm.