Measurement of Straightness for Two-Dimensional Translatory Stage

The large scaled and high accurate 2D-stage is necessary for nanomanufacturing. In order to measure the position of stage, two direction sensors are used. These sensors measure the displacement from the metrological frame. However in nanometer application, as the profile error of metrological frame is comparable with the accuracy of 2D-stage, it is not negligible. Therefore the measuring result includes the displacement of stages and the profile error of metrological frame. So the multi-probe method is applied in one-dimensional measurement to separate the displacement error from the profile error of the metrological frame. In the multi-probe method, the zero adjustment error cannot be removed. So this article proposes a new method which separates the displacement of 2D-stage from the profile errors of the metrological frames in two directions. In this article, as the laser interferometer is used as the sensor, the measuring data is assumed as the shape of the axis of stages mixed with the profile error of the reference mirror in laser interferometer. The relationship during the measuring data, the shape of the axis and the profile error is described. The shape of axis of stage and the profile error of mirror are derived from the measuring result in experiment.