Xiong Zheng, Liu Hua, Chen Ronghuan, Xu Jia, Li Qiankun, Li Jinhuan, Zhang Wenjuan
Opt Express. 2018 Jul 9;26(14):18597-18607. doi: 10.1364/OE.26.018597.
Illumination uniformity in photolithography systems determines the dimensional difference across the entire lithographic substrate. However, traditional lithography system relies on expensive and complex illumination system for achieving uniform illumination. In this paper, we propose a simple and cost-effective method based on the modulation of digital micromirror device to improve illumination uniformity. The modulation according to a digital mask achieved via an iteration program improves the uniformity to be above 95%. We demonstrate the effectiveness of the method by experimentally fabricating a linear grating. By implementing this method, the maximum dimensional difference is decreased from 3.3μm to 0.3μm. Further simulations indicate that higher uniformity is achievable once the field of view on the DMD is divided into smaller subregions.
光刻系统中的照明均匀性决定了整个光刻衬底上的尺寸差异。然而，传统光刻系统依靠昂贵且复杂的照明系统来实现均匀照明。在本文中，我们提出了一种基于数字微镜器件调制的简单且经济高效的方法来提高照明均匀性。通过迭代程序根据数字掩模进行的调制将均匀性提高到了95%以上。我们通过实验制作线性光栅证明了该方法的有效性。通过实施该方法，最大尺寸差异从3.3μm降至0.3μm。进一步的模拟表明，一旦将数字微镜器件上的视场划分为更小的子区域，就可以实现更高的均匀性。
