A Novel XY-Plane Positioning Based on Point Approximation for Wafer Stage Control

As semiconductor manufacturing technology became more sophisticated, the line width of circuits became narrower and the number of layers increased. Since small distortions easily lead to defects and the manufacturing process takes a lot of time, the importance of careful measurement has increased. For accurate measurement, it is important to accurately match the precision of hardware and various alignments. All alignments are important, but in this paper, we propose a point approximation calibration method based on the least squares method to improve the accuracy of the stage that plays the role of the absolute coordinate system for measurement.