计量学报2024，Vol.45Issue(8)：1115-1124,10.DOI:10.3969/j.issn.1000-1158.2024.08.05
晶圆校准器误差补偿与拟合算法的研究
Research on Error Compensation and Fitting Algorithms of Wafer Alignment Calibrator
摘要
Abstract
Wafer alignment calibrator plays a crucial role in semiconductor manufacturing and inspection processes.However,the accuracy of wafer center positioning can be affected by measurement errors.Consequently,the development of error compensation algorithms is paramount to refining the accuracy of wafer alignment calibrator.To address the impact of wafer carrier surface tilt on sampling accuracy,a physical model of a tilted wafer and its elliptical projection on the horizontal plane is established.An analytical relationship between the ellipse and the wafer center is derived from this model.Subsequently,an elliptical equation is employed for fitting purposes.To further enhance compensation and fitting accuracy,an extended Kalman filter-based ellipse fitting algorithm with a forgetting factor is proposed.This algorithm employs density-based spatial clustering of applications with noise for data preprocessing,coupled with improved progressive consistent sampling to improve the distribution of sample points.Additionally,an iterative reweighted least squares method is applied for ellipse fitting,resulting in high-precision estimation of the wafer center.Experimental results demonstrate that the proposed method achieves a fitting accuracy of 99.95％after error compensation,thus validating its effectiveness.关键词
几何量计量/晶圆校准器/误差补偿/椭圆拟合/顺序抽样一致性Key words
geometric measurement/wafer alignment calibrator/error compensation/elliptical fitting/random sample consensus分类
通用工业技术引用本文复制引用
刘暾东,陈锃琰,王若宇,唐之晨,郑鹏..晶圆校准器误差补偿与拟合算法的研究[J].计量学报,2024,45(8):1115-1124,10.基金项目
国家市场监管总局科技计划(2022MK138) （2022MK138）
