Study on a Positioning and Measuring System With Nanometer Accuracy

The process of developing a nanopositioning and nanomeasuring system is described. The piezoelectric micro-motion stage is based on the principle of inchworm motion. The traditional single actuator is updated to the double actuators. With the novel principle of push-pull relay movement the stage can move continuously and smoothly. In order to achieve nano-measurement a new method called coupled differential interferometry is proposed. An optical system with 8 times optical path difference is adopted. The new interferometer is simple in concept, without optical paths and easy to set up. In addition the real time error compensation of the interferential signals is accomplished by the Heydemann model. The experiment results show: the minimum step of the micro-motion stage is 18nm, the accuracy of the interferometry is 10–12nm.