Galaxy Microstructure: An Absolute Encoding Method for Planar 3-DOF Nanoscale Positioning Measurement

Microvision-based precision positioning measurement technology has emerged as a pivotal technology in the manufacturing of high-end equipment, including semiconductors and machine tools. Among the critical parameters, scholars consistently focus on the measurement range and resolution. However, these factors are often interdependent due to the constraints imposed by target pattern preparation accuracy, design methodology, and limitations of image registration algorithms. This article addresses these challenges by introducing a novel encoding pattern with ultraprecision diamond cutting, named the galaxy microstructure. This innovation achieves plane three-degree-of-freedom positioning measurement, surpassing the range-to-resolution ratio (R.R.) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{7}$ </tex-math></inline-formula>. The clear imaging mechanism and the distinctive coding method, grounded in ultraprecision processing, ensure the accuracy in pattern preparation and extend the measurement range. The robustness and accuracy of the coding unit feature positioning method guarantee high resolution and efficient positioning. Experimental validation confirms that the galaxy microstructure positioning method attains an impressive R.R. of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.6\times 10^{7}$ </tex-math></inline-formula> and boasts a processing efficiency of 20 Hz.