Fabrication of micro-lens arrays with moth-eye antireflective nanostructures using thermal imprinting process

We fabricated micro-lens arrays which have moth-eye antireflective nanostructures on their surfaces using thermal imprinting process and plasma treatment and characterized the morphology of the micro-lens arrays. After a micro-lens array shape was fabricated on a photoresist using photolithography and thermal reflow process, patterns were transferred onto a Ni stamp, and then micro-lens patterns were replicated on a polycarbonate film using thermal imprinting lithography. Using reactive ion etching, we were able to form the moth-eye antireflective nanostructures on the surface of polycarbonate films and polycarbonate micro-lens arrays. The AFM and SEM images of the plasma treated samples clearly show that the moth-eye nanostructures are formed on the surface. By measuring the transmittance spectrum using a UV–visible spectrometer, we also show that the moth-eye structures really act as antireflection coatings.