A novel method is proposed to improve contour accuracy of three-dimensional (3D) microstructure in real-time maskless lithography technique based on a digital micro-mirror device (DMD). In this paper, firstly according to the study of theory and experiment on exposure doses and exposure thickness relation, the spatial distribution of the photo-resist exposure doses was derived, which could predict the resulting 3D contour. Secondly, an equal-arc slicing strategy was adopted, in which arc lengths between adjacent slicing point are kept constant while layer heights become variant. And an equal-arc-mean slicing strategy that takes the average of adjacent layers height was also proposed to further optimize the quality of contour and reduce the contour error on the basis of the equal-arc slicing. Finally, to estimate the validity of the method and as a study case, aspheric micro-lens array were fabricated with proposed method in experiments. Our results showed that the proposed method is feasible for improving and enhancing the 3D microstructure contour accuracy and smoothness.

Date Published: 28 October 2016
PDF: 6 pages
Proc. SPIE 9683, 8th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, 96831P (28 October 2016); doi: 10.1117/12.2242366

Published in SPIE Proceedings Vol. 9683:
8th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies
Wenhan Jiang; Li Yang; Oltmann Riemer; Shengyi Li; Yongjian Wan, Editor(s)