针对DMD数字光刻, 利用ZEMAX光学设计软件, 设计出了一套适用于型号 0.7XGA DMD的10片式光刻投影物镜。该物镜采用非对称性结构, 前组为改进的三分离物镜, 后组为匹兹伐物镜加平像场镜, 分辨率为2 μm, 近轴放大倍率为-0.15, 像方数值孔径NA为0.158, 全视场波像差小于λ/20 , 畸变小于0.014%, 焦深为20 μm, 通过各项评价可知系统已经达到了衍射极限。在对该镜头进行公差分析后, 利用Monte Carlo方法, 模拟组装加工了100组镜头, 得到90%的镜头MTF＞0.46, 50%的镜头MTF＞0.51, 证明了这种非对称性结构加工和校装的可能性。

For the digital micromirror device (DMD) digital lithography, a ten-lenses projection objective was designed for DMD of model 0.7XGA by using Zemax optical design software. The projection objective uses the non-symmetrical structure, which has improved air-spaced triplet as front group and Petzval objective with flat field lens as back group, making it own higher resolution with 2 μm. Its paraxial magnification is -0.15, the image-side numerical aperture (NA) is 0.158, the wavefront aberration is less than λ/20, the distortion is less than 0.014% and focal depth is 20 μm. Through using Zemax to simulate, the system reaches diffraction limit theoretically. After tolerance analysis, by using Monte Carlo method, 100 groups of lenses were simulated for fabricating and assembling, results show that 90% of them could realize MTF＞0.46 and 50% could realize MTF＞0.51, which proves the possibility of fabricating and assembling such a non-symmetrical structure.