R2R (Roll-to-roll) production is a powerful process for patterning owing to its cost effectiveness and high productivity. Nanopatterned cylindrical molds for continuous fabrication of nanopatterned polymer film have been generally fabricated by various methods such as e-beam lithography, anodic oxidation, photolithography, or wrapping of nanopatterned sheets. However, these fabrication processes exhibit problems such as high economic and time costs, and creation of seam and stitch. In this paper, to overcome these problems, we suggest the cost-effective laser interference lithography (LIL) for fabrication of a nanopatterned cylindrical molds. LIL is a suitable process for fabricating high-resolution periodic nanometer patterns in large areas without the creation of seams or stitches. Periodic line patterns with hundred-nanometer periodicity were fabricated by LIL and pattern distortions were observed. Period and width of the line patterns on the cylindrical mold were measured along the circumference to experimentally confirm the distortion as related to the projection of light. Further, it was observed that the degree of distortion was dependent on the diameter of the cylindrical mold and the position along the circumference. However, it was theoretically expected that this distortion can be minimized below 0.2% by using a cylindrical mold with a sufficiently large diameter and control of the exposure area.
|