Dynamic photomask directed lithography based on electrically stimulated nematic liquid crystal architectures

Abstract

Abstract Lithography technology is a powerful tool for preparing complex microstructures through projecting the patterns of static templates with permanent features onto samples. To simplify fabrication and alignment processes, dynamic photomask for multiple configurations preparation becomes increasingly noteworthy. Hereby, we report a dynamic photomask by assembling the electrically stimulated nematic liquid crystal (NLC) into multifarious architectures. We demonstrate that these architectures give rise to reconfigurable and switchable diffraction patterns via electrically modulating the hybrid phase arising from the NLC molecules. These electrically configurable diffraction patterns are adopted as metamask to produce multiple microstructures with height gradients in one-step exposure and hierarchical microstructures through multiple in-situ exposures using standard photolithography. The fabricated pattern has feature size about 3.2 times smaller than the electrode pattern and can be transferred onto silicon wafer via etching. This strategy can be extended to design diverse microstructures with great flexibility and controllability, offers a promising avenue for fabricating metamaterials via complex structures with simplified lithography processes.