针对2 μm分辨力的光刻, 在以数字空间微反射器(DMD)为空间光调制器(SLM)的光刻系统中, 采用一种新的非对称式结构组合, 使用较少的透镜组成了一个高分辨力、大孔径的投影光刻镜头。利用ZEMAX 光学设计软件对其进行了建模和优化, 最终得到其全视场波像差小于λ/10, 畸变小于0.02％, 像方数值孔径NA=0.158, 最小分辨力为2 μm, 近轴缩小倍率β=-0.217, 其结果有效的减少了DMD 栅格效应对空间数字掩模图形的影响, 满足数字投影光刻光学系统的各项指标要求。最后, 对设计结果进行了公差分析, 在修改过少数几个默认公差后, 采用Monte Carlo 方法进行模拟装配, 证明了这种新结构镜头加工和校装的可行性。

For the 2 μm resolution lithography, in the lithography system with the digital micro-mirror device as space light modulator, we design a high resolution and large-area projection lens with new asymmetric structure assembly and fewer lens. By using ZEMAX optical design software to simulation-design and optimize, the results show that its optical path difference for entire field of view is less then λ/10, its distortion is less than 0.02％, its image space numerical aperture NA=0.158, its resolution is 2μm, its paraxial reduced ratio is β=-0.217. This can effectively reduce the DMD grid effect for the digital space mask and meet all kinds of requirement for projection lens optical system. Finally, we analyze the tolerance of the design results. By amending a few default tolerances and using the Monte Carlo method, it is verified the assembling and fabricating feasibility of this kind of new structure projection lens.