The Key Technical Research Of Nanometer Accuracy Measurements And Calibration Systems

With the increasing of the accurate of the modern manufacture, research on nanometer measurement method and establishing of nanometer calibration systems has been one important domain. This dissertation is based upon the project "the Research on Nanometer Calibration" (No. 60102102), and the "Study of Micro-position Systems for Nanometer Precision Calibration Technology" (No. 01153077) supported by the Aeronautic Science foundation of China. This paper mainly includes the following aspects:1. The deviation introduced by reference phase shifting errors on four-steps and five-steps algorithm are analyzed. Based on the principle of phase algorithm, a novel compensation method of reference phase-shifting error is described for four-steps algorithm and the five-steps algorithm. The theoretic analysis and data simulation indicate that the phase deviation arising from the first and the second harmonic reference phase-shifting errors can be eliminated using this method. By using a phase shifting interferometer with resolution of 0.1nm, the compensation method was experimentally verified.2. The application of the phase shifting interferometry in Nanometer Accuracy Measurement and Calibration Systems (NAMCS) is studied. The measuring system to measure the dimensional rotation errors of the NAMCS is configured. The principium experiment verified this method.3. The non-linearity errors in the heterodyne interferometry is investigated. For the heterodyne interferometer used within the nanometer and sub-nanometer region, the frequency leakages due to the imperfect optical elements and the thermal non-linearity drift restrict its uncertainty to about 20nm.A more comprehensive theoretic analysis for this non-linearity of heterodyne interferometer is given. The contribution of the phase quadrature error, the variable gains and the mean levels to the uncertainty of the phase meter are discussed.4.The compensation technology for non-linearity errors in heterodyneinterferometry is studied. One novel non-linearity compensation method is proposed based on the parameters estimation of the discrete interference signals. The effectiveness of the compensation method considering phase-quarter errors, unequal amplitude and the DC components are simulated. The experiments setup is founded, in which the micro-displacement is simulated by the variation of the gas's refractive index in the closed glass cavity. The results show that this method makes it possible to reduce the uncertainty from 20nm to less than 10nm.5. The structure of the cantilever flexure hinges is analyzed. The relations between the mode frequency, static characteristic and the framework parameters are studied. A two dimension crossed symmetric cantilever flexure hinge is investigated using finite elements method. The simulation of the mode frequency and the study of the relation between the displacements and the stress indicate that this flexure hinge has good flexibility and linearity between the displacement and the maximum stress. Moreover its motion range reaches to more than 100μm×00μ m.6. Experimental investigation of the motion specifications of two dimension stage based on above crossed symmetric flexure hinge. The position errors are measured by two dimension single-frequency laser interferometer, the pitch and yaw errors are tested using phase shifting interferometer with a resolution of 0.1nm, the linearity along motion axis is investigated by autocollimator with 0.01" uncertainty. These experiments establish the foundation for the orientation system in the subject of "Nanometer Accuracy Measurement And Calibration Systems" (NAMCS) and the data provide the information for the synthesize compensation technology.