Study On Active Vibration-Reduction System Of Simulated Vibration-Isolation Testing Table For Stepping And Scanning Lithography

The vibration of the work stage of the stepping and scanning lithography caused by the high acceleration of the exposure chuck and the reticle chuck will significantly affect the exposure quality. It is a key technology problem to enhance the relative stability of the chucks. In order to keep super precision of the lithography, the exposure parts must be isolated from the vibration caused by moving parts, which demanded vibration isolation and the active vibration reduction technology.This research work is sponsered by the project "Research on Vibration-Reduction and Vibration-Isolation Technology for Precision Machine" (granted number: 50390064) of the National Natural Science Foundation of China and Shanghai Committee of Science and Technology. Aimed at the precision vibration-isolation system of stepping and scanning lithography in the semiconductor industry application, the following several aspects have chiefly been carried on:(1)Precision active reduction vibration for the Lithography has been researched in China for the first time. The simulated vibration-isolation device is designed which can completely realize the given motion of the lithography. The H model precision ball-screw stages are applied as the positioning systems for the wafer stage and the linear motor stage is used as the positioning for the stencil stage. The active piezo-ceramic vibration-reduction system which can reduce vibration at 6 degrees is applied as the vibration system of the inner world form the outsides world of the simulated device. The air-bearing structures are used as the link between the driving systems and the wafer stage and the stencil stage. The bottoms of the wafer stage and the stencil stage are used vacuum air cushion. The friction between the bottoms and the supported stage can be avoided and vibration of the inner world from the motion systems partly can be reduced ,too.(2)Virtual model technology is applied to research structure parameters of the reduction vibration system for the testing table and principles and noticed proceedings are gived during the desgn of the reduction vibration system for lithography. The ADAMS multi-body dynamic model for the simulated vibration-isolation testing device of the stepping and scanning lithography is established to carry on optimized design and choice for the main structure parameters of the active vibration reduction system. Based on the model, the article analyses the dynamic performance affection of the working stage of the inner world when the main parameters of the vibration -reduction system are varied and some advice in allusion to the simulation results are put up to reform the dynamic performance of the inner world. At the same time, how to affect the dynamic performance of the inner world when other conditions are changed such as the difference for the quantity of the supporting points (3 points or 4 points), the nonlinear stiffness and damping for the vibration isolators.(3)Methods about confirmation for nature features of the active reduction vibration for lithography are research. The reference frame system of the inner world for the simulated vibration-isolation device is established and the six-degree dynamic model of the inner world is set up based on the reference frame system. According to the given parameters of the vibration isolators, the nature frequencies and the vibration model vectors are calculated. The results are very close to the results which are calculated by ANSYS software and results which are recongnized by experiment model parameter identifition method. The validity of the established mathematic model is proved.(4)The active control methods including single PID control and unioning PID control of the six-degree active vibration-reduction system for the simulated testing device are discussed and the associated simulation model using ADAMS software and MATLAB software is established. According to the model, the control methods of the PID controller and the uncompleted PID controller are researched and the results indicate that this method can improve the dynamic performance of the inner world and reduce the vibration from the outsides world effectively. Simlation results proves that the unioning PID control own better control effection than single PID control.(5)The key factors caused the vibration of the inner world and the transfer paths are analyzed amply and the testing research about the micro-vibration affection of the inner world caused by environment noise are carried on. The outside vibration frequency range is between 1Hz and 100Hz and the vibration magnitude is below 5um. Testing results that the designed system owns acceptable adaptation to enviroment vibration.(6)The testing stage for the simulated vibration-isolation testing device of the stepping and scanning lithography is put up and some experiments are completed. The results indicate that the vibration reduction parameters of the working stage for the inner world can meet the requirement of the designed targets.Research on precision vibration isolation system of Stepping and Scanning Lithography has a little relative report in overseas and no report in China. The research contexts, methods and results are both practical value and academic value to the analysis and design of the precision vibration-isolation for Stepping and Scanning lithography.