Development of a step micro-imprint lithography tool

Abstract

This paper proposes a UV imprint lithography process which uses a soft PDMS mold to transfer high resolution patterns at room temperature and low pressures conditions, and emphasizes reporting the development of the step micro-imprint lithography (SIL) tool for sub-micrometer patterning. The overall design of the machine and implementation of key units are described in detail. To eliminate the distortion of the soft mold in the loading process, distortion reduction by a load release process was proposed and applied in the SIL machine. By optimizing the loading process curve, an imprinting process curve was established. Furthermore, an overlay process using the load release and alignment error pre-compensation method was proposed to achieve high precision overlay for the SIL tool. Finally, various experiments were conducted to test the performance of the SIL apparatus. The experimental results show that the step micro-imprint lithography tool together with the proposed processes can replicate the sub-micrometer patterns with different feature sizes, different structures and different pattern sizes.