在数字光刻照明系统中,利用复眼透镜对365 nm发光二极管(LED)进行了匀光设计,透镜阵列采用近六边形的排列方式, 能基本覆盖圆形光。近六边形阵列相对于方形结构能减少无效透镜数量,能更有效地利用透镜发挥匀光效能。用软件分别仿真了近六边形、9×9方形透镜的照明系统, 并对比了其照度图,结果表明使用近六边形阵列的照明系统照度更为均匀。用近六边形阵列设计的照明系统与数字微反射镜(DMD)、 光刻镜头相结合,进行了2 μm精度的数字光刻实验,其像面照度均匀,线条清晰。

In digital lithography illumination system, 365 nm light emitting diode (LED) is designed by using fly’s-eye lens. The lens is arranged in a nearly hexagon array structure, which can basically cover the circular light. The nearly hexagon array can reduce the number of invalid lens compared with the traditional square structure, and the lens can be more effectively used to develop uniform light efficiency. The illumination systems with nearly hexagon array and 9×9 square fly’s-eye lens array are simulated respectively by software, and their irradiance maps are compared. Results show that the illumination system with nearly hexagon array is more uniform. The illumination system designed with the nearly hexagon array is combined with digital micro mirror device(DMD) and lithographic lens, and a digital lithography experiment with 2 μm precision is carried out. It’s found that the image surface illumination is uniform and line is clear.