中文摘要：

在综合分析了多种线性及非线性畸变后，建立了三次多项式图像系统畸变模型。采用基于控制点偏差目标函数最小优化法进行畸变模型的求解，并通过计算自标定偏差均方差与互标定偏差均方差对标定结果进行了评定。结果表明，模型求解误差为0．22μm，通过校正标记图像几何畸变引入的定位误差由2．5μm降低到0．25μm，可实现压印对正系统中标记图像几何畸变的校正，实现精确定位。

英文摘要：

A distortion model based on cubic polynomial is established concerning various linear and nonlinear distortions in the alignment system based on video image for multi-level imprint lithography and a calibration technique based on controlled points is adopted to solve the model. By minimizing the error object function, the indeterminate coefficients of the distortion model are obtained. The calibration results are evaluated by the standard deviation of calibration error, and the results show that the fitting error is 0.22 μm. By introducing distortion correction based on this model, the alignment error due to image geometric distortion in the alignment system is reduced from 2.5 μm to 0.25 μm, which meets the requirement of precise positioning of alignment marks.