Abstract
In order to improve the utilization ratio of light source in LCD display, we propose to replace the traditional absorption polarizer with the reflection nano-polarizer, and combine with nanoimprint lithography technology to achieve the goal of mass production of nano-polarizer. Accordingly, the nanoimprint mold plays a critical role in nanoimprint process. There are many different methods to fabricate the nanoimprint mold, for example, optical lithography, E-beam lithography and so on. Amount these techniques, laser interference lithography provides an inexpensive, rapid and easy way to fabricate nano-patterns. To fabricate high density and large-area nano-patterns, some ameliorated interference lithography systems have been proposed. However, these interference lithography systems are either complicated or expensive. The objective of this study is aimed at designing a compact and cost-effective interference lithography system and by step-and-tiling method to fabricate large-area nanoimprint mold. Interference lithography is based on the interference of two or more coherent laser beams incident from different directions intersect on a photoresist-coated substrate. The resulting fringes recorded in the photoresist can be used to fabricate 1-D or 2-D period structures. In this study, we first consider the standing wave effect in interference lithography. By establishing a Hardmask design model and combine with the use of ARC, we can reduce the standing wave effect more effectively. The experimental set-up used in this work is Lloyds-mirror . To combine with the two-axis nano-stage and maintain the stability and precision of nano-stage, we designed a horizental-type Lloyd’s-mirror set-up and verified the viability. Besides, to better understand the factors that contribute to the fabrication of nanoimprint mold, we also consider the experiment process recipe, the mask material suit for this set-up, and the optimum condition for tiling. Similarly, a two-dimensional pattern can be generated by superposition of two sinusoidal standing waves with this sep-up. In the consideration of cost-effective condition, the compact interference lithography system not only provides a rapid way to fabricate large-area nanoimprint mold but has the advantage of flexibility in fabricating different dimensional period structures.