超大数值孔径(NA)光刻成像中,掩模保护膜上的入射光线入射角范围增大,用传统方法优化掩模保护膜难以增大斜入射光的透射率。基于薄膜光学原理提出一种新的掩模保护膜优化方法,确保光线在整个入射角范围内的平均透射率最大。利用琼斯矩阵方法探讨膜层的透射属性和相位特征,得到相应的琼斯光瞳来分析膜层带来的偏振像差。结果表明,对比传统的掩模保护膜优化方法,新方法能有效提高斜入射光线的透射率,减小膜层引起的偏振像差。新的掩模保护膜优化方法能为超大NA光刻成像的掩模保护膜设置提供必要的理论基础和技术支撑。 In the case of NA NA lithography, the incidence angle of incident light on the mask protective film increases. It is difficult to increase the transmittance of oblique incident light by the conventional method of optimizing the mask protective film. Based on the principle of thin film optics, a new optimization method of mask protection film is proposed to ensure the maximum average transmittance of light over the entire incident angle. The Jones matrix method is used to explore the transmission properties and phase characteristics of the film, and the corresponding Jones pupil is obtained to analyze the polarization aberration caused by the film. The results show that, compared with the traditional mask protection film optimization methods, the new method can effectively improve the transmittance of oblique incident light and reduce the polarization aberration caused by the film. The new mask protection film optimization method can provide the necessary theoretical basis and technical support for the mask protection film setting of the large NA lithography imaging.