Investigation of Nanometer XY Positioning Stage

An improved XY positioning stage having a coplanar structure design, which makes the guide planes in X- and Y-directions are of the same height. As a result, the Abbe's error and the cumulative error can be reduced. Symmetric structure, linear slide ways and low thermal expansion material are all considered to achieve low structure distortion and thermal shift with impacted force and temperature change. Finite element analysis modeling techniques were used to optimize the configuration and parameters of the stage. Integrated with ultrasonic actuator and the linear diffraction grating interferometer, the straightness of the guide way and the measuring repeatability of the stage have been proved. Experimental results have shown that the stage has a higher straightness less than 5" and the repeatability less than 30 nm in fine motion