Real-time mask-division technique based on DMD digital lithography

Digital lithography technique is a promising tool for the fabrication of binary optical element. In this paper, we present the mask-division technique to improve the lithography quality. A piece of high-frequency mask is divided into several pieces of low-frequency binary masks. Then they are imaged on the photoresist successively by using the DMD-based lithography system. Based on the theory of partial coherent light, the intensity distribution in image plane has been simulated. The grating masks with period of 4 μm have been fabricated by using the mask-division technique. Experimental results demonstrate the feasibility of the proposed method as an effective technique for advancing the edge sharpness.