硅片对准标记经过光刻工艺后产生的非对称变形会导致对准测量误差,目前普遍采用工艺验证的方法修正此对准测量误差,但该方法存在一定的工艺适应性问题。针对该对准测量误差,提出了一种新的修正方法,即利用非对称变形对准标记在不同照明波长和偏振态情况下的对准位置差异,修正对准标记非对称变形导致的对准误差,提高了对准的工艺适应性。并将该方法拓展应用于套刻测量误差修正,提高了套刻测量的工艺适应性。

The asymmetric deformation of silicon wafer alignment mark after lithography process causes an alignment error. Currently, such errors are typically calibrated via process verification; however, this method is challenged by its lack of process adaptability. Herein, we present a new calibration method which uses the differences in alignment positions of the asymmetrically deformed wafer alignment marks under illuminations with different wavelengths and polarizations to calibrate the alignment error, and the proposed method exhibits good process adaptability. Additionally, the proposed calibration method is extended to calibrate the overlay measurement error, improving the process adaptability of overlay measurement.