非理想照明光瞳对光刻成像质量的影响

Impact of Non-ideal Illumination Pupil on Imaging Performance of Lithography

通过PROLITH光刻仿真软件研究了非理想照明光瞳对光刻成像质量的影响以及图形位置偏移量对光瞳偏心的敏感度随数值孔径NA和相干因子σ的变化规律。仿真结果表明:在无像差的理想光学系统中,光瞳偏心主要影响图形的位置偏移量,图形的位置偏移量与离焦量成线性关系,直线的斜率随着偏心量的增大而增大。光瞳偏心对H-Vbias和焦深(DOF)的影响较小。光瞳偏心和极不平衡性两者对图形位置偏移量的综合影响是这两者单独引起的图形位置偏移量的叠加。

The impact of Non-ideal illumination pupil on imaging performance of lithography is calculated using software PROLITH. Effect of the sensitivity of image CD placement error caused by a shift of illumination with numerical aperture （NA） and coherent factor （a） is also calculated. Calculations show that the main effect of a shift of illumination on imaging performance of lithography is the image CD placement error in the ideal optical systems. The image CD placement error caused by a shift of illumination is proportional to the defocus, and the slope of line increases with increasing the shift of illumination. A shift of illumination has little effect on H-V bias and Depth of Focus （DOF）. The impact of a shift of illumination and pupil filling unbalance on image CD placement error is the sum of the CD placement error induced separately.