A high precision X-Y-theta micropositioning stage has been developed as an aligner for optical reduction projection and electron beam exposure in lithography system. The micropositioning stage is designed to correct XY axes positioning errors and yaw error due to coarse positioning. In order to achieve large rotation about the theta-axis, the designed stage uses a special monolithic flexure pivoted mechanism. Three piezoelectric actuators with flexure-pivoted mechanical lever system amplifies the rotation range effectively. In addition, to improve immunity to temperature gradients, the micropositioning stage is designed rationally symmetric about the Z-axis. Open-loop characteristics of the micropositioning stage were measured by capacitance displacement transducers. Experimetnal results indicate that the micropositioning stage has 0.025 mum positioning accuracy over the total range of 38 mum and 30 mum along the X and Y axes, respectively. It also has 0.2 arcsec yaw accuracy over the total range of 350 arcsec about the theta-axis.
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