Influence Function Measurement Technique Using the Direct and Indirect Piezoelectric Effect for Surface Shape Control in Adaptive Systems

Since the introduction of adaptive systems for corrective measures, static and dynamic disturbances have been reduced through manipulation surface shape in a well-controlled manner. One important application where are highly needed is future photo-lithography machines, particularly wafer table affect overlay focus performance. To reduce errors, dense array actuators must be integrated into to apply both in- out-of-plane deformations surface. realize certain shape, influence functions linearly superimposed. Accurate models result an accurate prediction final shape. calibration function every actuator needs determined. Here, we propose technique rapidly measure function: measurement (IFM) technique. Using actuate-sense property piezoelectric materials, determined by activating one piezo-actuator measuring charge induced on neighboring piezo-actuators. The measured charges compared results finite element simulations absolute difference 0.3 % reported inter-actuator coupling parameters. This clearly indicates potential proposed Note Practitioners—A critical step during integrated-circuit lithographic fabrication process exposure. A particular practical challenge this correct mismatch between optical image plane surface, caused deformations. negatively impacts mismatch, can embedded counteract deformations, overall superposition each actuator’s function. As part actuators, their stored. However, errors arise when not actuator. Additionally, different wafers, vary hence should done per wafer. takes time throughput. Our paper presents viable approach that reduces active tables, which also relevant other such as deformable mirrors. requires mechanically coupled, it limited continuous surfaces. numerically tested experimentally verified demonstrate