DEVELOPMENT OF A HIGH PRECISION CO-PLANAR XY STAGE WITH MULTI-DEGREE-OF-FREEDOM SENSING SYSTEM

Kuang-Chao Fan, Hung-Yu Wang, Shih-Hsin Hsu, Li-Min Chen

Abstract

With the continuing trend toward device miniaturization in many engineering and scientific fields, the need to accomplish highly-precise measurements at the micro- or nano scale has emerged as a critical concern. In practice, the accuracy of high-precision machines is affected by the Abbe principle due to inevitable angular errors during motion. Therefore, this study focuses on the development of a high precision nanometer level co-planar XY stage with miniature multi-degree-of-freedom measurement system (MDFMS). <BR />The symmetric structural design of the co-planar stage is considered to eliminate the structure deformation due to force and temperature changes. The MDFMS is constructed by a wavelength corrected Michelson interferometer and a coaxial dual-axis autocollimator. The wavelength correction of the miniature laser interferometer is achieved by employing a holographic grating so that the real-time mean wavelength of the laser diode can be detected to the resolution of 0.001 nm. Controlling the temperature within 20 ± 2°C, the wavelength stability is less than 10^-6. Conventional complicated frequency stabilization technique is no more needed. In addition, using the laser diode as the light source, the MDFMS can be reduced to a small physical size so as to be used as the feedback sensor in the stage. The autocollimator has a resolution of 0.1 arc-sec and accuracy of ±0.3 arc-sec within the range of ±30 arc-sec in both axes. These detected angular errors can be used to compensate for the Abbe error if the functional point of the stage is at a certain Z-height, or called the Abbe offset. Experimental results show that, after error compensations, the positioning error can be controlled to ±20 nm for the travel up to 20 mm long.

Keywords

co-planar stage, Abbé error, Multi-degree-of-freedom Measurement System (MDFMS), wavelength correction

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IMEKO-TC14-2014-74.pdf

DOI

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IMEKO TC

TC14 - Measurement of Geometrical Quantities

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